Hypertension-induced Cardiac Hypertrophy Research Articles

Exercise-induced cardiac mitochondrial reorganization and enhancement in spontaneously hypertensive rats.

The myocardium is a highly oxidative tissue in which mitochondria are essential to supply the energy required to maintain pump function. When pathological hypertrophy develops, energy consumption augments and jeopardizes mitochondrial capacity. We explored the cardiac consequences of chronic swimming training, focusing on the mitochondrial network, in spontaneously hypertensive rats (SHR). Male adult SHR were randomized to sedentary or trained (T: 8-week swimming protocol). Blood pressure and echocardiograms were recorded, and hearts were removed at the end of the training period to perform molecular, imaging, or isolated mitochondria studies. Swimming improved cardiac midventricular shortening and decreased the pathological hypertrophic marker atrial natriuretic peptide. Oxidative stress was reduced, and even more interesting, mitochondrial spatial distribution, dynamics, function, and ATP were significantly improved in the myocardium of T rats. In the signaling pathway triggered by training, we detected an increase in the phosphorylation level of both AKT and glycogen synthase kinase-3 β, key downstream targets of insulin-like growth factor 1 signaling that are crucially involved in mitochondria biogenesis and integrity. Aerobic exercise training emerges as an effective approach to improve pathological cardiac hypertrophy and bioenergetics in hypertension-induced cardiac hypertrophy.

TIGAR Deficiency Blunts Angiotensin-II-Induced Cardiac Hypertrophy in Mice.

Hypertension is the key contributor to pathological cardiac hypertrophy. Growing evidence indicates that glucose metabolism plays an essential role in cardiac hypertrophy. TP53-induced glycolysis and apoptosis regulator (TIGAR) has been shown to regulate glucose metabolism in pressure overload-induced cardiac remodeling. In the present study, we investigated the role of TIGAR in cardiac remodeling during Angiotensin II (Ang-II)-induced hypertension. Wild-type (WT) and TIGAR knockout (KO) mice were infused with Angiotensin-II (Ang-II, 1 µg/kg/min) via mini-pump for four weeks. The blood pressure was similar between the WT and TIGAR KO mice. The Ang-II infusion resulted in a similar reduction of systolic function in both groups, as evidenced by the comparable decrease in LV ejection fraction and fractional shortening. The Ang-II infusion also increased the isovolumic relaxation time and myocardial performance index to the same extent in WT and TIGAR KO mice, suggesting the development of similar diastolic dysfunction. However, the knockout of TIGAR significantly attenuated hypertension-induced cardiac hypertrophy. This was associated with higher levels of fructose 2,6-bisphosphate, PFK-1, and Glut-4 in the TIGAR KO mice. Our present study suggests that TIGAR is involved in the control of glucose metabolism and glucose transporters by Ang-II and that knockout of TIGAR attenuates the development of maladaptive cardiac hypertrophy.

Lipoamide Attenuates Hypertensive Myocardial Hypertrophy Through PI3K/Akt-Mediated Nrf2 Signaling Pathway

AbstractThe process of myocardial hypertrophy in hypertension can lead to excessive activation of oxidative stress. Lipoamide (ALM) has significant antioxidant and anti-inflammatory effects. This study aimed to investigate the effects of ALM on hypertension-induced cardiac hypertrophy, as well as explore its underlying mechanisms. We evaluated the effects of ALM on spontaneously hypertensive rats and rat cardiomyocytes treated with Ang II. We found that ALM was not effective in lowering blood pressure in SHR, but it attenuated hypertension-mediated cardiac fibrosis, oxidative stress, inflammation, and hypertrophy in rats. After that, in cultured H9C2 cells stimulated with Ang II, ALM increased the expression of antioxidant proteins that were decreased in the Ang II group. ALM also alleviated cell hypertrophy and the accumulation of ROS, while LY294002 partially abrogated these effects. Collectively, these results demonstrate that ALM could alleviate oxidative stress in cardiac hypertrophy, potentially through the activation of the PI3K/Akt-mediated Nrf2 signaling pathway. Graphical Abstract

Glucagon-like peptide-1 attenuates cardiac hypertrophy via the AngII/AT1R/ACE2 and AMPK/mTOR/p70S6K pathways.

Glucagon-like peptide-1 (GLP-1), a novel type of glucose-lowering agent, has been reported to exert cardioprotective effects. However, the cardioprotective mechanism of GLP-1 on spontaneous hypertension-induced cardiac hypertrophy has not been fully elucidated. In this study, we revealed that liraglutide or alogliptin treatment ameliorated spontaneous hypertension-induced cardiac hypertrophy, as evidenced by decreased levels of cardiac hypertrophic markers (atrial natriuretic peptide, brain natriuretic peptide, and β-myosin heavy chain), as well as systolic blood pressure, diastolic blood pressure, mean arterial pressure, and histological changes. Both drugs significantly reduced the levels of angiotensin II (AngII) and AngII type 1 receptor (AT1R) and upregulated the levels of AngII type 2 receptor (AT2R) and angiotensin-converting enzyme 2 (ACE2), as indicated by a reduced AT1R/AT2R ratio. Simultaneously, treatment with liraglutide or alogliptin significantly increased GLP-1 receptor expression and adenosine monophosphate-activated protein kinase (AMPK) phosphorylation and downregulated the phosphorylation of mammalian target of rapamycin (mTOR), p70 ribosomal S6 protein kinase, and eukaryotic translation initiation factor 4E binding protein 1 in spontaneous hypertension rats. Furthermore, our data demonstrated that the AMPK inhibitor compound C or mTOR activator MHY1485 inhibited the anti-hypertrophic effect of GLP-1. In summary, our study suggests that liraglutide or alogliptin protects the heart against cardiac hypertrophy by regulating the expression of AngII/AT1R/ACE2 and activating the AMPK/mTOR pathway, and GLP-1 agonist can be used in the treatment of patients with cardiac hypertrophy.

Apigenin Improves Hypertension and Cardiac Hypertrophy Through Modulating NADPH Oxidase-Dependent ROS Generation and Cytokines in Hypothalamic Paraventricular Nucleus.

Apigenin, identified as 4', 5, 7-trihydroxyflavone, is a natural flavonoid compound that has many interesting pharmacological activities and nutraceutical potential including anti-inflammatory and antioxidant functions. Chronic, low-grade inflammation and oxidative stress are involved in both the initiation and progression of hypertension and hypertension-induced cardiac hypertrophy. However, whether or not apigenin improves hypertension and cardiac hypertrophy through modulating NADPH oxidase-dependent reactive oxygen species (ROS) generation and inflammation in hypothalamic paraventricular nucleus (PVN) has not been reported. This study aimed to investigate the effects of apigenin on hypertension in spontaneously hypertensive rats (SHRs) and its possible central mechanism of action. SHRs and Wistar-Kyoto (WKY) rats were randomly assigned and treated with bilateral PVN infusion of apigenin or vehicle (artificial cerebrospinal fluid) via osmotic minipumps (20μg/h) for 4weeks. The results showed that after PVN infusion of apigenin, the mean arterial pressure (MAP), heart rate, plasma norepinephrine (NE), Beta 1 receptor in kidneys, level of phosphorylation of PKA in the ventricular tissue and cardiac hypertrophy, perivascular fibrosis, heart level of oxidative stress, PVN levels of oxidative stress, interleukin 1β (IL-1β), interleukin 6 (IL-6), iNOS, monocyte chemotactic protein 1 (MCP-1), tyrosine hydroxylase (TH), NOX2 and NOX4 were attenuated and PVN levels of interleukin 10 (IL-10), superoxide dismutase 1 (Cu/Zn-SOD) and the 67-kDa isoform of glutamate decarboxylase (GAD67) were increased. These results revealed that apigenin improves hypertension and cardiac hypertrophy in SHRs which are associated with the down-regulation of NADPH oxidase-dependent ROS generation and inflammation in the PVN.

Loss of Chloride Channel 6 (CLC-6) Affects Vascular Smooth Muscle Contractility and Arterial Stiffness via Alterations to Golgi Calcium Stores.

Genome-wide association studies have found a number of potential genes involved in blood pressure regulation; however, the functional role of many of these candidates has yet to be established. One such candidate gene is CLCN6, which encodes the transmembrane protein, chloride channel 6 (ClC-6). Although the CLCN6 locus has been widely associated with human blood pressure regulation, the mechanistic role of ClC-6 in blood pressure homeostasis at the molecular, cellular, and physiological levels is completely unknown. In this study, we demonstrate that rats with a functional knockout of ClC-6 on the Dahl Salt-Sensitive rat background (SS-Clcn6) have lower diastolic but not systolic blood pressures. The effect of diastolic blood pressure attenuation was independent of dietary salt exposure in knockout animals. Moreover, SS-Clcn6 rats are protected from hypertension-induced cardiac hypertrophy and arterial stiffening; however, they have impaired vasodilation and dysregulated intracellular calcium handling. ClC-6 is highly expressed in vascular smooth muscle cells where it is targeted to the Golgi apparatus. Using bilayer electrophysiology, we provide evidence that recombinant human ClC-6 protein can function as a channel. Last, we demonstrate that loss of ClC-6 function reduces Golgi calcium stores, which may play a previously unidentified role in vascular contraction and relaxation signaling in vascular smooth muscle cells. Collectively, these data indicate that ClC-6 may modulate blood pressure by regulating Golgi calcium reserves, which in turn contribute to vascular smooth muscle function.

Qingda granule attenuates angiotensin II-induced cardiac hypertrophy and apoptosis and modulates the PI3K/AKT pathway

Qingda granule (QDG), simplified from Qingxuan Jiangya Decoction, is a well-known traditional Chinese medicine formula that has been used for decades to treat hypertension. However, the cardioprotective effects of QDG on Ang II-induced hypertension remain unknown. This study aimed to investigate the effects of QDG on hypertension-induced cardiac hypertrophy and apoptosis, as well as explore its underlying mechanisms. Mice were infused with Ang II (500 ng/kg/min) or saline solution as control, then administered oral QDG (1.145 g/kg/day) or saline for two weeks. QDG treatment attenuated the elevation in blood pressure caused by Ang II, as well as the decreased left ventricle ejection fractions and fractional shortening. Moreover, QDG treatment significantly alleviated the Ang II-induced elevation of the ratio of heart weight to tibia length, as well as cardiac injury, hypertrophy, and apoptosis. In cultured H9C2 cells stimulated with Ang II, QDG partially reversed the increase in cell surface area and number of apoptotic cells, up-regulation of hypertrophy markers ANP and BNP, and activation of caspases-9 and -3. QDG also partially reversed Ang II-induced accumulation of reactive oxygen species (ROS), depolarization of the mitochondrial membrane, release of cytochrome C, up-regulation of Bax, and decrease in levels of p-PI3K, p-AKT, and Bcl-2. These results suggest that QDG can significantly attenuate Ang II-induced hypertension, cardiac hypertrophy and apoptosis, and it may exert these effects in part by suppressing ROS production and activating the PI3K/AKT signaling pathway.

Redox Regulation of Cardiac ASK1 (Apoptosis Signal-Regulating Kinase 1) Controls p38-MAPK (Mitogen-Activated Protein Kinase) and Orchestrates Cardiac Remodeling to Hypertension.

Systemic hypertension increases cardiac workload causing cardiomyocyte hypertrophy and increased cardiac fibrosis. An underlying feature is increased production of reactive oxygen species. Redox-sensitive ASK1 (apoptosis signal-regulating kinase 1) activates stress-regulated protein kinases (p38-MAPK [mitogen-activated protein kinases] and JNKs [c-Jun N-terminal kinases]) and promotes fibrosis in various tissues. Here, we determined the specificity of ASK1 signaling in the heart, with the hypothesis that ASK1 inhibitors may be used to manage fibrosis in hypertensive heart disease. Using immunoblotting, we established that moderate levels of H2O2 activate ASK1 in neonatal rat cardiomyocytes and perfused rat hearts. ASK1 was activated during ischemia in adult rat hearts, but not on reperfusion, consistent with activation by moderate (not high) reactive oxygen species levels. In contrast, IL (interleukin)-1β activated an alternative kinase, TAK1 (transforming growth factor-activated kinase 1). ASK1 was not activated by IL1β in cardiomyocytes and activation in perfused hearts was due to increased reactive oxygen species. Selonsertib (ASK1 inhibitor) prevented activation of p38-MAPKs (but not JNKs) by oxidative stresses in cultured cardiomyocytes and perfused hearts. In vivo (C57Bl/6J mice with osmotic minipumps for drug delivery), selonsertib (4 mg/[kg·d]) alone did not affect cardiac function/dimensions (assessed by echocardiography). However, it suppressed hypertension-induced cardiac hypertrophy resulting from angiotensin II (0.8 mg/[kg·d], 7d), with inhibition of Nppa/Nppb mRNA upregulation, reduced cardiomyocyte hypertrophy and, notably, significant reductions in interstitial and perivascular fibrosis. Our data identify a specific reactive oxygen species→ASK1→p38-MAPK pathway in the heart and establish that ASK1 inhibitors protect the heart from hypertension-induced cardiac remodeling. Thus, targeting the ASK1→p38-MAPK nexus has potential therapeutic viability as a treatment for hypertensive heart disease.

Leech extract: A candidate cardioprotective against hypertension-induced cardiac hypertrophy and fibrosis

The prevalence of cardiovascular diseases (CVDs) has been increasing worldwide. Despite significant improvements in therapeutics and on-going developments of novel targeted-treatment regimens, cardiac diseases lack effective preventive and curative therapies with minimal side effects. Therefore, there is an urgent need to identify and propagate alternative and complementary therapies against cardiovascular diseases. Some traditional Chinese medicines can contribute to the prevention and treatment of CVDs and other chronic diseases, with few side effects. Hirudo, a medicinal leech, has been acclaimed for improving blood circulation and overcoming blood stagnation; however, the precise molecular mechanisms of leech extract treatment against pathological cardiac remodeling remain elusive. In this study, we aimed to delineate the molecular mechanisms of medicinal leech extract in the treatment of cardiac hypertrophy and fibrosis, using both in vitro and in vivo assessments. We conducted in vitro and in vivo animal experiments, including cell-viability assays, fluorescence microscopy, immunoblotting, immunohistochemistry, and Masson's trichrome staining. Pre-treatment with leech extract conferred a survival benefit to spontaneously-hypertensive rats (SHRs) and significantly reduced angiotensin II (ANG II)-induced cardiac hypertrophy and fibrosis. ANG II-stimulated cardiac hypertrophy markers were attenuated by leech extract treatment, versus controls. Translational expression of stress-associated mitogen-activated protein kinases (MAPKs) was also repressed. In vivo, leech extract treatment significantly ameliorated the cardiac hypertrophy phenotype in SHRs and diminished interstitial fibrosis, accompanied with reduced fibrosis markers. Leech extract treatment under a hypertensive condition exerted significant cardio-protective benefits by reducing the expression of cardiac hypertrophy-related transcription factors, stress-associated MAPKs, and fibrosis mediators. Our findings imply that medicinal leach extract may be effective against hypertension-induced cardiac hypertrophy and fibrosis.

054 Potential New Treatment Based on FKBPL for Hypertension-Induced Cardiac Hypertrophy

054 Potential New Treatment Based on FKBPL for Hypertension-Induced Cardiac Hypertrophy

Nanoparticles for regenerative medicine.

NanomedicineVol. 14, No. 15 Journal WatchFree AccessNanoparticles for regenerative medicineMarina Pöttler, Iwona Cicha, Harald Unterweger, Christina Janko, Ralf P Friedrich & Christoph AlexiouMarina PöttlerDepartment of Otorhinolaryngology, Head & Neck Surgery, Section of Experimental Oncology & Nanomedicine (SEON), Else Kröner-Fresenius-Stiftung-Professorship, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Glueckstr. 10a, 91054 Erlangen, GermanySearch for more papers by this author, Iwona CichaDepartment of Otorhinolaryngology, Head & Neck Surgery, Section of Experimental Oncology & Nanomedicine (SEON), Else Kröner-Fresenius-Stiftung-Professorship, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Glueckstr. 10a, 91054 Erlangen, GermanySearch for more papers by this author, Harald UnterwegerDepartment of Otorhinolaryngology, Head & Neck Surgery, Section of Experimental Oncology & Nanomedicine (SEON), Else Kröner-Fresenius-Stiftung-Professorship, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Glueckstr. 10a, 91054 Erlangen, GermanySearch for more papers by this author, Christina JankoDepartment of Otorhinolaryngology, Head & Neck Surgery, Section of Experimental Oncology & Nanomedicine (SEON), Else Kröner-Fresenius-Stiftung-Professorship, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Glueckstr. 10a, 91054 Erlangen, GermanySearch for more papers by this author, Ralf P FriedrichDepartment of Otorhinolaryngology, Head & Neck Surgery, Section of Experimental Oncology & Nanomedicine (SEON), Else Kröner-Fresenius-Stiftung-Professorship, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Glueckstr. 10a, 91054 Erlangen, GermanySearch for more papers by this author & Christoph Alexiou*Author for correspondence: E-mail Address: c.alexiou@web.deDepartment of Otorhinolaryngology, Head & Neck Surgery, Section of Experimental Oncology & Nanomedicine (SEON), Else Kröner-Fresenius-Stiftung-Professorship, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Glueckstr. 10a, 91054 Erlangen, GermanySearch for more papers by this authorPublished Online:2 Aug 2019https://doi.org/10.2217/nnm-2019-0162AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareShare onFacebookTwitterLinkedInRedditEmail Keywords: cilia restorationnanoparticles for functional recoveryosteogenesisremyelinationtissue regenerationMagnetic-assisted osteogenesis in a 3D collagen modelEvaluation of: Yuan Z, Memarzadeh K, Stephen AS, Allaker RP, Brown RA, Huang J. Development of a 3D collagen model for the in vitro evaluation of magnetic-assisted osteogenesis. Sci. Rep. 8(1),16270 (2018) – written by Marina PöttlerBiological behavior of cells can be modified with an induced magnetic field if magnetic nanoparticles are localized within the cells or associated with cell membrane. A high magnetic gradient can lead to a shift of the nanoparticles along the gradient vector, which causes compression and stretch forces on the cell membrane. This phenomenon can be very useful for regenerative medicine, especially for tissues that need mechanical forces as growth- and proliferation-stimuli. Although magnetic stimulation was previously used to induce bone regeneration [1], the underlying mechanisms are not well understood.To gain more insights in such process, Yuan et al. used static magnetic fields in a 3D cell culture model in order to induce the growth of MG-63 human osteosarcoma cells. Magnetic nanoparticles, which were taken up by the cells, served as internal stimulus and the applied static magnetic field was used as an external growth-promoting stimulus. Cells were cultured in a 3D collagen bioreactor for up to 42 days and were analyzed for proliferation, differentiation, mineralization and gene expression. The cells in the scaffold were exposed to the magnetic field alone, the nanoparticles alone, or a combination of both.Compared with unstimulated controls, cell proliferation was induced in all three treatment groups between day 1 and 14. After 21 days, cell differentiation was significantly increased in cells stimulated with magnetic field alone, and even more in cells exposed to the combination of nanoparticles and magnetic field, whereas cells stimulated with nanoparticles alone did not show an increase in differentiation. A higher level of mineralization was detected in scaffolds exposed to magnetic fields at day 21, but after 42 days no differences in mineralization were seen between the samples, indicating that stimulation with a magnetic field can induce earlier mineralization. Using real time-PCR, the authors investigated the expression of several key genes for osteogenesis including, Runx2, osteonectin-encoding SPARC gene, BMP-2 and BMP-4. Runx2 was upregulated using the combination of nanoparticles and magnetic field after 7 and 14 days. Osteonectin-encoding SPARC was only upregulated by combined stimuli at day 7, but at day 14, the control group reached the same level. BMP-2 and BMP-4 were also only upregulated by the combination of both stimuli at all time points.The presented biomimetic 3D collagen model allows long-term culture of cells, which are associated with magnetic nanoparticles and can thus respond to magnetic stimulation. Using this tool, the authors demonstrated that the combination of static magnetic field and magnetic nanoparticles can enhance osteogenesis of MG-63 by upregulating the expression of Runx2, SPARC, BMP-2 and BMP-4. These data indicate the great potential of their model as a platform to study the mechanisms of magnetic stimulation in osteogenesis, which can also be applied to other applications in tissue regeneration research.Magnetic particles for targeted drug delivery & remote control of primary ciliaEvaluation of: Pala R, Mohieldin AM, Sherpa RT et al. Ciliotherapy: remote control of primary cilia movement and function by magnetic nanoparticles. ACS Nano 13(3), 3555-3572 (2019) – written by Iwona Cicha and Christoph Alexiou.Primary cilia, membrane-bound organelles protruding into extracellular space, participate in mechanosensory and chemosensory signaling in most human cell types. Defects in cilia functions or structure (ciliopathies) lead to a wide spectrum of organ specific but also systemic disorders, such as polycystic kidney disease, hypertension, cardiovascular disorders and aberrations of vascular homeostasis [2]. To address this problem, Pala et al. have previously designed cilia-targeted nanosystems carrying an experimental drug fenoldopam, which acts by extending cilia length [3]. The particles were based either on metal (Au) or polymer poly(lactic-co-glycolic acid) (PLGA) core and, when tested in a mouse model of hypertension induced by endothelium-specific knockout of polycystin-2-encoding PKD2 gene, effectively reduced blood pressure, improved heart function and increased nitric oxide bioavailability, as compared with free fenoldopam-treated animals.Most recently, the authors investigated the possibility of further improving functionality of their nanosystem by using magnetic particles. The resulting ciliotherapeutic construct was based on iron oxide nanoparticles loaded with fenoldopam and targeted to cilia (CT-IO-F) using antibodies directed to dopamine receptor type 5. The specific targeting of primary cilia was confirmed both in vitro and in vivo. Using CT-IO-F in combination with an external magnetic field, the movement of the nonmotile cilium was induced. Both magnetic and flow-induced cilia movement improved their function as shown by increased calcium signaling and nitric oxide (NO) production both in porcine kidney cell line LLC-PK1 and in isolated primary endothelial cells. Compared with free fenoldopam, intravenously administered CT-IO-F strongly reduced blood pressure in a mouse model of PKD2 knockout-induced hypertension, which was further decreased in animals receiving nanoparticles in the presence of magnetic field. After 8 weeks of blood pressure studies, heart function was examined ex vivo, showing pronounced hypertrophy and functional decline in hypertensive controls. In contrast, CT-IO-F particles improved left ventricular pressure, stroke volume, ejection fraction and overall cardiac output. Importantly, in the animals receiving CT-IO-F in combination with magnetic stimulation applied every 72 h, cardiac function was further improved returning to the levels of wild-type, nonciliopathic controls.In conclusion, the functional regeneration of primary cilia in a mouse model of hypertension using the developed CT-IO-F was strongly vasculo- and cardioprotective. By efficient targeting of cilia and the resulting increase in calcium signaling leading to NO synthesis, the ciliotherapeutic magnetic nanoparticles prevented the hypertension-induced cardiac hypertrophy in mice. These data suggest that targeted restoration of primary cilia length and motility can represent a promising treatment option in patients with cilia dysfunction-related diseases.Nanoparticle-based pH buffer prevents the PLGA-induced inflammationEvaluation of: Lih E, Kum CH, Park W et al. Modified magnesium hydroxide nanoparticles inhibit the Inflammatory response to biodegradable poly(lactide-co-glycolide) implants. ACS Nano 12(7), 6917–6925 (2018) – written by Harald Unterweger.Synthetic biodegradable polymers, such as PLGA, have been widely used as coating or matrix material in drug delivery, tissue engineering and regenerative medicine applications. In vivo, these systems degrade by hydrolysis of their ester bonds, resulting in acidic degradation byproducts. Yet, these acidic byproducts can react with the surrounding tissue, leading to the induction of (chronic) inflammation, which can cause the subsequent failure of the system [4]. In their work, Lih et al. developed a method to incorporate uniformly dispersed Mg(OH)2 nanoparticles in a PLGA matrix. To achieve this and prevent the particles from aggregation during the incorporation process, their surface was modified in a two-step process with ricinoleic acid and L-lactide, leading to the formation of oligolactide on the particle surface. In contrast to the unmodified nanoparticles (15 wt%), the functionalized Mg(OH)2 particles incorporated in the PLGA matrix led to a smooth polymer surface with a uniform Mg distribution. Additional advantage of the uniform particle distribution was an increase in tensile strength. In a degradation study, the composite material could maintain the pH of the system closely at neutral pH, while the pure PLGA material caused a significant drop in pH below 3.In vitro studies with human umbilical vein endothelial cells showed an increase in cell viability for the composite material (90 vs 40%). Additional ELISA experiments with human umbilical vein endothelial cells and the U937 monocytic cell line also demonstrated reduced expression of important inflammation markers, IL-6 and TNF-α, respectively. Two in vivo studies were performed to confirm the advantages of the composite material. In the first study, coronary stent implantation was performed in a porcine model of neointima formation. Compared with the control PLGA stent, the composite stent achieved a better regeneration of the tissue, with significantly lower arterial wall injury, inflammation and fibrin scores, resulting in improved prevention of in-stent restenosis. The second in vivo study was performed in a mouse model of partial nephrectomy, aiming at the reconstruction of renal glomerular tissue. One week after implantation, the composite scaffold led to higher cell densities and a more glomerular-like tissue structure compared with pure PLGA scaffolds. In addition, the secretion of inflammatory proteins was also significantly reduced in response to the composite implants.All in all, these data indicate the great potential of the buffered-PLGA matrix to amend the drawbacks associated with PLGA implants and may facilitate the clinical translation of such systems in the future.M2 macrophage polarization by IL-4-loaded nanoparticles for functional muscle recoveryEvaluation of: Raimondo TM, Mooney DJ. Functional muscle recovery with nanoparticle-directed M2 macrophage polarization in mice. Proc. Natl Acad. Sci. USA 115(42), 10648–10653 (2018) – written by Christina Janko.Whereas acute inflammation helps to kill invaders, persisting chronic inflammation contributes to the progression of many diseases. During acute infection, circulating monocytes differentiate into macrophages with pro-inflammatory M1 phenotype. Afterward, macrophages switch toward an anti-inflammatory multiple sclerosis (MS) phenotype that supports healing and tissue regeneration [5]. The imbalance of M1 over M2 macrophages can cause excessive chronic inflammation leading to tissue damage or insufficient regeneration, for example, of skeletal muscles after injury [6]. An anti-inflammatory cytokine, IL-4, is explored as potential therapeutic agent in various inflammatory diseases [7]. Of note, IL-4 can induce the switch from M1 to M2 phenotype, however, its short half-life resulting in the need of repeated high dose infusions and systemic side effects limit its in vivo use [8].To deliver IL-4 to the target tissue, Raimondo and Mooney synthesized gold nanoparticles (referred to as PA4), which were partially PEG-stabilized and loaded with IL-4 to the remaining gold surface. PA4, which had hydrodynamic diameter of 30 nm, were stable in medium containing 10% serum and released less than 1% of IL-4 after 7 days. PA4 showed no toxicity toward THP-derived macrophages but upregulated CD206 (M2a marker) to the same extent as soluble IL-4, indicating full bioactivity of nanoparticle-bound IL-4. Contrarily, CD163 (M2c marker) or CCR7 (M1 marker) were not upregulated. PA4-induced M2 polarization of macrophages persisted longer (5 days) than observed with soluble IL-4. Additionally, increasing IL-4 valency on PA4 resulted in higher levels of M2a polarization. The efficacy of PA4 was tested in vivo in C57BL6/J mice with ischemic tibialis anterior muscle. Upon treatment with intramuscular injection of soluble IL-4 or PA4, hematoxylin/eosin staining revealed immune cell infiltration after 3 days, which had disappeared in both study groups after 12 days. Additionally, muscle fiber area was increased. Control mice treated with unloaded nanoparticles did not show immune cell infiltration or muscle fiber gain. At 12 days postinjection, PA4 treated mice showed even higher contraction force and velocity compared with mice receiving soluble IL-4 bolus, unloaded nanoparticles or PBS. Flow cytometry of immune cell infiltrating into the injured tibialis anterior muscles showed a more rapid clearance of CD45+ immune cells, monocytes and macrophages in PA4 group compared with PBS-treated controls. Analyzing the macrophage phenotypes, PA4-treated mice showed an increase in CD206+ cells and decrease in CD80+ cells compared with PBS group, indicating a switch from M1 to M2a phenotype. Interestingly, bolus IL-4 and unloaded nanoparticles reduced M1, but did not promote M2a. To determine if the shift of M1 to M2a played a role in muscle regeneration, macrophages were depleted before ischemic injury using clodronate. With macrophage depletion and PA4 treatment, muscle contraction force and velocity were reduced compared with mice receiving PA4 without macrophage deletion, indicating their central role for muscle regeneration.Summarizing, the ability of PA4 to direct M2 macrophage polarization may be beneficial not only in the treatment of muscular dystrophies, but also in the treatment of various other inflammatory conditions.Nanoparticle-based remyelination of the CNS in a rat modelEvaluation of: Youssef AEH, Dief AE, El Azhary NM, Abdelmonsif DA, El-Fetiany OS. LINGO-1 siRNA nanoparticles promote central remyelination in ethidium bromide-induced (EB) demyelination in rats. J. Physiol. Biochem. 75(1), 89–99 (2019) – written by Ralf P Friedrich.Multiple sclerosis (MS) is one of the most common neurological disorders of the CNS. MS is characterized by the loss of the myelin sheath, resulting in demyelinating plaques with variable degrees of inflammation, gliosis and neurodegeneration [9,10]. The treatment of MS is currently limited to drugs with anti-inflammatory or immunomodulatory activity that inhibit inflammation-driven tissue injury [11]. Current developments in MS therapy aim to stop or reverse the demyelination process itself, for example, by influencing the signaling pathways involved in myelination process. As an example, inhibition of LINGO-1, which belongs to the family of leucine-rich repeat proteins playing key roles in CNS biology, is known to promote remyelination in CNS by stimulating oligodendrocyte precursor cells [12,13].Addressing this pathway, Yousseff et al. produced chitosan nanoparticles loaded with LINGO-1 siRNA (LINGO-1 siRNA NPs) and investigated the effect of their intranasal administration in a rat model of EB demyelination. The noninvasive intranasal route enables bypassing of the blood–brain barrier to deliver drugs directly to the CNS [14], whereas the EB model, which triggers an extended demyelination lesion, enables a clear temporal separation between de- and remyelination processes. Various behavioral studies using beam balance test, foot fault test, rotarod test and inverted screen test, showed significantly improved balance and coordination, paw strength, reduced numbers of foot slippage and an increased latency to fall off the rotating rod after treatment with LINGO-1 siRNA NPs compared with untreated EB animals. Quantitative RT-PCR and western blot analysis revealed a strong increase in myelin basic protein mRNA and protein expression in EB rats treated with LINGO-1 siRNA NPs compared with the controls. Moreover, LINGO-1 siRNA NPs protected animals against neural apoptosis, as evidenced by decreased caspase-3 activity, and decreased LINGO-1 mRNA and protein expression in pontine tissue. Finally, histopathological analysis of the pontine tissue in LINGO-1 siRNA NP-treated EB rats showed a partial protection of the axons from demyelination in the demyelination group and more compact myelin sheaths within the demyelinated lesions of the remyelination group. In agreement with previous reports on the neuroprotective effects of chitosan [15], chitosan NPs without siRNA also increased the mRNA and protein expression of myelin basic protein although their effects were less pronounced as compared with LINGO-1 siRNA NPs.Thus, based on behavioral testing, biochemical parameters and histopathological findings, intranasal administration of LINGO-1 siRNA NPs led to a significant improvement of neurological disturbances in the rat model of EB-induced demyelination. These data suggest that noninvasive intranasal administration of LINGO-1 siRNA NPs could represent a promising therapy for MS.Financial & competing interests disclosureThe authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.No writing assistance was utilized in the production of this manuscript.

The TIR/BB-loop mimetic AS-1 prevents Ang II-induced hypertensive cardiac hypertrophy via NF-\u03baB dependent downregulation of miRNA-143

Untreated pathological cardiac hypertrophy, which can be caused by sustained systemic hypertension, may lead to heart failure. In the present study, we investigated whether AS-1 had attenuating effects on hypertension-induced cardiac hypertrophy, and whether this process was mediated by the regulation of miRNA-143. To induce the hypertrophic response in vitro, cardiomyocytes were stimulated with Ang II for 24hs. AS-1 administration strongly attenuated Ang II-induced hypertrophic response of cardiomyocytes. Chronical infusion of Ang II via implanted osmotic mini-pump induced increased blood pressure and cardiac hypertrophy in vivo. AS-1 administration attenuated hypertension-induced cardiac hypertrophy by, at least in part, inhibin of MAPK signaling. We observed, for the first time, upregulated expression of miRNA-143 in Ang II-induced cardiomyocytes, and inhibition of miRNA-143 significantly reduced the Ang II-induced hypertrophic responses. Importantly, AS-1 administration diminished the Ang II-induced upregulation of miRNA-143. Overexpression of miRNA-143 abolished the attenuating effects of AS-1 on Ang II-induced hypertrophic response of cardiomyocytes. Additionally, AS-1 administration abrogates Ang II-induced nuclear translocation of p50 NF-κB subunit in hypertrophic cardiomyocytes. Application of NF-κB inhibitor significantly suppressed Ang II-induced upregulation of miRNA-143. Our data suggest a novel mechanism by which AS-1 attenuates Ang II-induced hypertrophic response through downregulation miRNA-143 expression in a NF-κB-dependent manner.

Acetyltransferase p300 inhibitor reverses hypertension-induced cardiac fibrosis.

Epigenetic dysregulation plays a crucial role in cardiovascular diseases. Previously, we reported that acetyltransferase p300 (ATp300) inhibitor L002 prevents hypertension‐induced cardiac hypertrophy and fibrosis in a murine model. In this short communication, we show that treatment of hypertensive mice with ATp300‐specific small molecule inhibitor L002 or C646 reverses hypertension‐induced left ventricular hypertrophy, cardiac fibrosis and diastolic dysfunction, without reducing elevated blood pressures. Biochemically, treatment with L002 and C646 also reverse hypertension‐induced histone acetylation and myofibroblast differentiation in murine ventricles. Our results confirm and extend the role of ATp300, a major epigenetic regulator, in the pathobiology of cardiac hypertrophy and fibrosis. Most importantly, we identify the efficacies of ATp300 inhibitors C646 and L002 in reversing hypertension‐induced cardiac hypertrophy and fibrosis, and discover new anti‐hypertrophic and anti‐fibrotic candidates.

Recent Developments on the Crosstalk Between STAT3 and Inflammation in Heart Function and Disease.

The transcription factor STAT3 has a protective function in the heart. Until recently, the role of STAT3 in hypertension-induced cardiac hypertrophy was unsettled. Earlier studies revealed that global reduction of STAT3 activity reduced cardiac hypertrophy with hypertension, but caused a disruption of myofilaments and increased contractile dysfunction. However, newer studies with cardiomyocyte-specific deletion of STAT3 indicate that STAT3 does not cause cardiac hypertrophy with increased blood pressure. Rather, cardiac STAT3 is important for maintaining metabolic homeostasis, and loss of STAT3 in cardiomyocytes makes the heart more susceptible to chronic pathological insult, for example by disrupting glucose metabolism and protective signaling networks via the upregulation of certain microRNAs. This scenario has implications for understanding peripartum cardiomyopathy as well. In viral myocarditis, STAT3 opposes the initiation of the dilated phenotype by maintaining membrane integrity via the expression of dystrophin. STAT3 signaling was also found to attenuate myocarditis by polarizing macrophages to a less inflammatory phenotype. On the other hand, STAT3 contributes to immune-mediated myocarditis due to IL-6-induced complement component C3 production in the liver, as well as the differentiation of Th17 cells, which play a role in initiation and development of myocarditis. Besides canonical signaling pathways, unphosphorylated STAT3 (U-STAT3) and redox-activated STAT3 have been shown to couple to transcription in the heart. In addition, tissue signaling cytokines such as IL-22 and IL-17 have been proposed to have actions on the heart that involve STAT3, but are not fully defined. Understanding the novel and often protective aspects of STAT3 in the myocardium could lead to new therapeutic approaches to treat heart disease.

2018 AHA Late-Breaking Basic Science Abstracts.

HomeCirculation ResearchVol. 123, No. 122018 AHA Late-Breaking Basic Science Abstracts Free AccessAbstractPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessAbstractPDF/EPUB2018 AHA Late-Breaking Basic Science Abstracts Originally published6 Dec 2018https://doi.org/10.1161/RES.0000000000000236Circulation Research. 2018;123:e69–e81Late-Breaking Basic Science Oral Abstracts I19701Whole Genome Sequencing Identifies PTGIS as a Novel Susceptibility Gene for Idiopathic Pulmonary Arterial HypertensionXiao-jian Wang1, Xi-qi Xu1, Kai Sun1, Ke-Qiang Liu2, Su-Qi Li1, Xin Jiang1, Qin-Hua Zhao3, Lan Wang3, Zhi-Cheng Jing1; 1Fuwai Hosp, Chinese Academy of Med Sciences and Peking Union Med College, Key Laboratory of Pulmonary Vascular Medicine, State Key Laboratory of Cardiovascular Disease, Beijing, China, Beijing, China, 2Institute of Basic Med Sciences, Chinese Academy of Med Sciences and Peking Union Med College, Beijing, China, 3Shanghai Pulmonary Hosp, Tongji Univ Sch of Medicine, Beijing, ChinaBackground: Idiopathic pulmonary arterial hypertension (IPAH) is a rare disease with high heritability. The inactivating mutation in the major predisposing gene bone morphogenetic protein receptor 2 (BMPR2) could only account for about 15–20% IPAH cases. The genetic etiology remains unknown for a large number of IPAH cases.Methods: The whole-genome sequencing was performed in a discovery cohort including 42 IPAH patients who are spare of BMPR2 mutations. Putative genes were validated in an independent cohort that included 188 IPAH patients without BMPR2 mutation and 968 healthy controls. Functional assessments were conducted to analyze the potential effects of candidate genetic mutations on transcript splicing, enzymatic activity and function.Results: An enrichment of rare variants in the gene encoding prostacyclin synthase (PTGIS) in IPAH was initially identified in the discovery cohort and further confirmed in the replication cohort. In the combined cohorts, fourteen patients (6.1%) were heterozygous for three PTGIS mutations, including one splice-site mutation (c.521+1G>A) and two missense mutations (R252Q, A447T). These mutations conferred a 7.8-fold greater risk of IPAH (P=5.0 x 10–6). In acute pulmonary vasoreactivity testing, iloprost induced more significantly decrease of pulmonary vascular resistance (P=0.001) and increase of cardiac index (P<0.001) in patients with PTGIS variants than those without. The functional studies indicated that the c.521+1G>A mutation resulted in aberrant mRNA transcripts. The two missense mutations caused a decrease in prostacyclin production and increased cell death in pulmonary microvascular endothelial cells.Conclusion: We have identified three loss-of-function mutations in PTGIS gene from two independent IPAH cohorts. These results provide a novel insight underlying the genetic basis of PTGIS mutations involved in the pathogenesis of IPAH.Download figureDownload PowerPointAuthor Disclosures: X. Wang: None. X. Xu: None. K. Sun: None. K. Liu: None. S. Li: None. X. Jiang: None. Q. Zhao: None. L. Wang: None. Z. Jing: None.Key Words: Pulmonary hypertension; Genetics; Prostacyclin19712High-throughput Drug Screen to Reverse Phenotype of Pulmonary Artery Hypertension Ipsc Derived Vascular Cells Combined with Bioinformatics Uncovers Promising TherapiesMingxia Gu, Michele Donate, Yifei Miao, Shuai Mao, Toshie Saito, Shoichiro Otsuki, Lingli Wang, Rebecca Harper, Silin Sa, Purvesh Khatri, Marlene Rabinovitch; STANFORD SCHOOL OF MEDICINE, Stanford, CAPulmonary arterial hypertension (PAH) is a progressive disorder characterized by endothelial cell (EC) apoptosis and smooth muscle cell (SMC) hyperproliferation, that leads to occlusive vascular remodeling. Current PAH therapies only improve symptoms, but do not reverse the pathological changes that underlie PAH. In this study, we used a high-throughput screen to identify compounds that reverse PAH EC and SMC dysfunction in a patient-specific manner. Induced pluripotent stem cell derived ECs (i-EC) generated from six PAH patients were exposed to 4,500 compounds and assayed for improved cell survival following serum withdrawal using the caspase assay. We identified a tyrosine kinase inhibitor (TKIx) that improved PAH i-EC survival, promoted angiogenesis, and suppressed aberrant growth of SMC in all the patients we tested. Interestingly, this TKIx was superior to other TKIs (e.g. imatinib) in improving EC functions in association with increasing BMPR2 as well as the co-receptors BMPR1a/1b and the downstream activator ID1. Using the LINCS database, we identified pathways regulated by TKIx that were inverse to a PAH disease signature generated by analysis of multiple transcriptomic profiles from control and PAH patients available on the GEO database. The transcriptional co-activators Creb3 and 5 that interact with Smad1/5 were selectively up-regulated by TKIx, explaining the increase in expression of ID1, BMPR2 and co-receptors. In the Sugen/hypoxia rat model of PAH, TKIx reduced right ventricular systolic pressure and PA occlusive changes. Lung organ culture from PAH patients treated with TKIx for seven days, showed reduced PA neointimal lesions and increased gene expression of Creb3, Apelin, eNOS, and BMP receptors. Further screening identified another two compounds effective in all PAH i-EC lines, and 13 compounds that were effective in i-EC subgroups, indicating a patient-specific response. One antioxidant effective in 5 out of the 6 i-EC lines also performed well in reversing aberrant PAH SMC proliferation and resistance to apoptosis. Our study suggests that using iPSC derived vascular cells combined with bioinformatics can identify novel compounds and pathways that reverse PAH pathology and can be optimized for patient specific selectivity.Author Disclosures: M. Gu: None. M. Donate: None. Y. Miao: None. S. Mao: None. T. Saito: None. S. Otsuki: None. L. Wang: None. R. Harper: None. S. Sa: None. P. Khatri: None. M. Rabinovitch: None.Key Words: Pulmonary hypertension; Pulmonary vascular biology; Stem cells; Endothelial function; Drugs19653Identification Of Dna Methyltransferase 3b As A Novel Epigenetic Mediator Against Pulmonary Vascular Remodeling In Pulmonary HypertensionYi Yan1, Yang-Yang He1, Ji-Wang Chen2, Jun-Han Zhao1, Jue Ye1, Hong-Da Zhang1, Tian-Yu Lian1, Ru-Jiao Zhang3, Shan-Shan Guo4, Xu Zhang5, Xin Jiang1, Xi-Qi Xu1, Yong Wang6, Zhi-Cheng Jing1; 1Key Laboratory of Pulmonary Vascular Medicine & FuWai Hosp, State Key Laboratory of Cardiovascular Disease, National Cntr for Cardiovascular Diseases, Chinese Academy of Med Sciences & Peking Union Med College, Beijing, China, 2Section of Pulmonary, Critical Care Medicine, Sleep and Allergy, Dept of Medicine, Univ of Illinois at Chicago, Chicago, IL, 3Hebei Univ Health Science Cntr, Baoding, China, 4Dept of Biochemistry, Pharmaceutical College, Henan Univ, Kaifeng, China, 5Key Laboratory of Human Disease Comparative Medicine, Institute of Laboratory Animal Science, Chinese Academy of Med Sciences & Peking Union Med College, Beijing, China, 6Dept of Respiration, Beijing Shijitan Hosp, Capital Med Univ, Beijing, ChinaIntroduction: DNA methyltransferase 3B (DNMT3B) is recognized as an epigenetic modulator of cellular biological behavior and involves in various disease process. Our previous study identified that deficiency in DNMT3B accelerates the pathological process of pulmonary hypertension (PH), suggesting a therapeutic role of DNMT3B against deleterious vascular remodeling.Methods: The effect of DNMT3B overexpression on migration in human PASMCs after PDGF-BB stimulation was examined. We also interrogated the effect of excessive DNMT3B by intratracheal instillation of AAV in PH mice after exposure to hypoxia. RNA sequencing was performed in hPASMCs after AdDNMT3B or control vector infection. Putative genes mediated by DNMT3B were validated by qPCR in hPASMCs under the stimuli.Results: Constitutive high-level human DNMT3B largely abolished the impact of PDGF-BB on migration in hPASMCs compared to control group at each examined time point. In vitro study showed overexpression of human DNMT3B elicited a remarkable reduction in right ventricular systolic pressure (31.0 ± 0.7 vs. 34.3 ± 0.8mmHg, P < 0.01) and right ventricular hypertrophy index (0.29 ± 0.01 vs. 0.37 ± 0.02, P < 0.01) compared to control mice in response to hypoxia. Furthermore, vascular remodeling was mitigated with the excessive DNMT3B as evidenced by the suppression of media thickness and arteriolar muscularization. Transcriptional profiling analysis revealed 222 transcripts express differentially in response to DNMT3B overexpression. KEGG pathway analysis highlighted inflammation-related processes as the most changed pathways. Of all the putative genes, CCL5 was demonstrated to be downregulated in AdDNMT3B infected hPASMCs in the presence or absence of PDGF-BB.Conclusions: Our data suggest DNMT3B could rescue the pathological remodeling and a crucial epigenetic link to CCL5 induction that engenders malfunction in PASMCs and pathogenesis of PH.Download figureDownload PowerPointAuthor Disclosures: Y. Yan: None. Y. He: None. J. Chen: None. J. Zhao: None. J. Ye: None. H. Zhang: None. T. Lian: None. R. Zhang: None. S. Guo: None. X. Zhang: None. X. Jiang: None. X. Xu: None. Y. Wang: None. Z. Jing: None.Key Words: Pulmonary hypertension; Pulmonary vascular biology; Vascular disease19716Hymecromone Inhibits Fibrotic Deposition and Pulmonary Hypertension in an Experimental Model of Combined Pulmonary Fibrosis and EmphysemaScott Collum1, Jose G Molina1, Ankit Hanmandlu1, Weizhen Bi1, Ning-Yuan Chen1, Mesias Pedroza2, Tingting Weng1, Tinne C Mertens1, Cory Wilson1, Michael R Blackburn1, Soma S Jyothula1, Harry Karmouty-Quintana1; 1UTHealth-McGovern Med Sch, Houston, TX, 2Baylor College of Medicine, Houston, TXBackground: Combined pulmonary fibrosis and emphysema (CPFE) was identified as a syndrome in 2005. This syndrome predominantly affects male smokers or ex-smokers, it has a mortality rate of 55% and a median survival of 5 years. A highly fatal complication of CPFE is pulmonary hypertension (PH) that is observed in over 50% of patients. The presence of PH plummets 1-year survival rates to 60%. Despite this dismal prognosis, no “curative” therapies exist for patients with CPFE outside of lung transplantation and no agents are recommended to treat PH. This highlights the need to develop novel treatment approaches for CPFE. Studies from our group have demonstrated that adenosine and its receptor, ADORA2B, are elevated in chronic lung diseases. Activation of ADORA2B leads to elevated levels of hyaluronan synthases and increased hyaluronan, a glycosaminoglycan which contributes to chronic lung injury.Hypothesis: We hypothesize that ADORA2B and hyaluronan contribute to chronic lung injury in CPFE.Methods: Using isolated lung tissue from patients with CPFE, we characterized expression levels of ADORA2B and hyaluronan synthases (HAS). Next using a unique model of experimental lung injury that replicates features of CPFE, namely airspace enlargement, PH and fibrotic deposition, we investigated whether hymecromone, a hyaluronan synthase inhibitor, is able to inhibit features of chronic lung disease.Results: We demonstrate increased levels of ADORA2B and HAS3 in lungs from patients with CPFE that were also elevated in our experimental model of lung injury. Treatment with hymecromone was able to attenuate PH and fibrotic deposition but not airspace enlargement. This was accompanied by a reduction of HAS3 positive macrophages.Conclusions: We have generated pre-clinical data demonstrating the capacity of hymecromone, a FDA-approved drug, to attenuate features of CPFE in an experimental model of chronic lung injury.This research has received full or partial funding support from the American Heart Association.Author Disclosures: S. Collum: None. J.G. Molina: None. A. Hanmandlu: None. W. Bi: None. N. Chen: None. M. Pedroza: None. T. Weng: None. T.C.J. Mertens: None. C. Wilson: None. M.R. Blackburn: None. S.S.K. Jyothula: None. H. Karmouty-Quintana: Research Grant; Significant; AHA 14SDG18550039.Key Words: Pulmonary hypertension; Fibrosis; Pulmonary19644A Novel Rat Model For Heritable Pulmonary Arterial HypertensionSu-Qi Li1, Xiao-Jian Wang1, Zi-Chao Lv1, Chun-Yan Cheng1, Shao-Fei Liu1, Si-Jin Zhang2, Yuan-Qing Tan1, Zhi-Cheng Jing1; 1the Key Laboratory of Pulmonary Vascular Medicine, State Key Laboratory of Cardiovascular Disease, FuWai Hosp, National Cntr for Cardiovascular Diseases, Chinese Academy of Med Sciences and Peking Union Med College, Beijing, China, 2Shanghai Pulmonary Hosp, Tongji Univ Sch of Medicine, Shanghai, ChinaIntroduction: A number of genetically engineered mouse models have been generated with a loss-of-function mutation on BMPR2 gene to study the pathogenesis of PAH. However, current mice models may not fully represent the pathology of clinical PAH. Hemodynamic and imageological measurements are difficult to obtain in mice. To understand the role of BMPR2 mutation in the development of PAH, we firstly constructed a novel rat model with Bmpr2 hotspot mutation and examined the phenotype.Methods: Using genetic testing, 670 IPAH/FPAH cases have been screened for BMPR2 mutation to find the hotspot mutation. SD rats carrying the heterozygous hotspot mutation were constructed by CRISPR/Cas9. The phenotypic characteristics were compared between Bmpr2 mutant and wild-type rats at baseline or exposed to hypobaric hypoxia (50Kpa, 10%O2) for 3 weeks.Results: According to the BMPR2 mutation spectrum, p.R491W (c.C1471T) was found to be the hotspot mutation. Rats carrying R491W mutation were apparently normal at baseline. However, after the hypobaric hypoxia treatment, the mutant rat showed more severe pulmonary vascular remodeling phenotype and RV hypertrophy. Compared to the wild-type littermates, the RVSP and RV/ (LV+S) were increased by 12% and 21% respectively in Bmpr2R491W rats. Echocardiographic assessment showed that the RV free wall thickness of Bmpr2R491W rats were 1.14 times that of wild-type rats, the TAPSE and right ventricular outflow tract cardiac output were reduced by 20% and 59%, respectively. The ratio of fully muscularized arteries and the wall thickness of muscularized pulmonary arteries (< 75μm in diameter) were greater in Bmpr2R491W rats.Conclusion: We firstly constructed the transgenic rat model with a hotspot missense mutation Bmpr2R491W related to PAH. Bmpr2R491W rats are more susceptible to hypoxia-induced pulmonary arterial hypertension than wild-type rats to be an ideal rodent model to study the molecular mechanism of BMPR2 missense mutation.Download figureDownload PowerPointAuthor Disclosures: S. Li: None. X. Wang: None. Z. Lv: None. C. Cheng: None. S. Liu: None. S. Zhang: None. Y. Tan: None. Z. Jing: None.Key Words: Gene mutations; Hypoxia; Pulmonary vascular biology; Ventricular remodelingLate-Breaking Basic Science Oral Abstracts II19702Therapeutic Targeting of Interleukin-11 with Neutralizing Antibodies Prevents Cardiac FibrosisWei-Wen Lim1, Ben Corden1, Viswanathan Sivakumar2, Anissa Widjaja2, Jessie Tan2, Lei Ye1, Xie Chen1, Shi jie Ko2, Liping Su1, Nicole Tee1, Brijesh Kumar Singh2, Sebastian Schaefer1, Stuart Cook1; 1National Heart Cntr Singapore, Singapore, Singapore, 2Duke-NUS, Singapore, SingaporeIntroduction: Cardiac fibrosis is a common pathology in heart failure and is associated with poor outcome. We previously identified interleukin-11 (IL11) as a critical pro-fibrotic factor in the heart: IL11 is elevated in preclinical models of cardiac disease, its upregulation is sufficient to drive fibrosis and IL11 receptor alpha (Il11ra) deleted mice are protected. To translate our findings, we developed first-in-class therapeutic IL11RA-binding antibodies for use in preclinical models of heart disease.Methods: Mouse monoclonal antibodies against IL11RA were developed using genetic immunization and tested for the ability to inhibit cardiac fibroblast activation in vitro. The strongest neutralizing antibody (X209) was taken forward for in vivo use. In a pressure-overload model, C57BL/6J mice were subjected to either sham surgery or transverse aortic constriction (TAC). Mice were randomized to be given 20mg/kg of anti-IL11RA or control antibody. In a model of metabolic syndrome, mice were fed either normal diet or a high fat/high fructose Western diet and were randomized for antibody treatments. Cardiac fibrosis and inflammation were assessed by qPCR, Western blot, histology and collagen assays.Results: X209 effectively blocked fibroblast activation in vitro and reduced the secretion of fibrosis markers downstream of multiple pro-fibrotic stimuli. In the TAC model, X209 significantly reduced the expression of fibrotic and inflammatory genes and reduced cardiac collagen levels 2-fold versus control (P<0.001). The degree of LV hypertrophy and systolic function was similar in both antibody treatments. Mice on a Western diet developed cardiac fibrosis (collagen increase 1.5-fold, P=0.01), which was reduced by administration of X209.Conclusions: Neutralizing anti-IL11RA antibodies block pro-fibrotic signaling in vitro and reduce cardiac fibrosis in mouse models of heart disease. These studies identify a new approach for treating cardiac fibrosis.Download figureDownload PowerPointAuthor Disclosures: W. Lim: None. B. Corden: None. V. Sivakumar: None. A. Widjaja: None. J. Tan: None. L. Ye: None. X. Chen: None. S. Ko: None. L. Su: None. N. Tee: None. B. Kumar Singh: None. S. Schaefer: Ownership Interest; Modest; S.A.C. and S.Scha. are co-inventors of the patent application (WO2017103108) ‘Treatment of fibrosis’., S.A.C. and S.Scha. are co-founders and shareholders of Enleofen Bio PTE LTD, a company that develops therapeutics based on findings described in this abstract. S. Cook: Ownership Interest; Modest;.A.C. and S.Scha. are co-inventors of the patent application (WO2017103108) ‘Treatment of fibrosis’., S.A.C. and S.Scha. are co-founders and shareholders of Enleofen Bio PTE LTD, a company that develops therapeutics based on findings described in this manuscript.Key Words: Fibrosis; Heart failure19670Molecular Imaging of Autophagy Impairment in Hypertrophic CardiomyopathyLan Wei1, Heather K Bowditch1, Samuel A Ding1, Sydney Weng1, Choukri Mekkaoui2, David E Sosnovik2, Robert M Blanton1, Gordon S Huggins1, Howard H Chen1; 1Tufts Med Cntr, Boston, MA, 2Massachusetts General Hosp, Harvard Med Sch, Boston, MAIntroduction: Hypertrophic cardiomyopathy (HCM), a genetic disease effecting 1 in 500 people, is often asymptomatic but leads to heart failure and sudden death. Current technology cannot detect HCM until cardiac dysfunction or myocardium thickening occurs. A GWAS study identified FHOD3-V1151I variant that strongly associates with HCM. FHOD3 is highly expressed in cardiomyocytes (CMs), and contains a LC3-interacting region. LC3 is a hallmark of autophagy that recognizes p62, a scaffold to mediate protein turnover during autophagy. We hypothesize that CM autophagy is important to maintain cellular structure and function, and plays a role in HCM.Methods: In HCM patient myectomy samples, we characterized FHOD3, LC3, and p62 by western blot. In H9C2 rat myoblasts, we overexpressed FHOD3 WT and V1151I variant, and assessed autophagy quantitatively with a lysosome-targeting autophagy detecting nanoparticle (ADN) by FACS and confocal microscopy. FHOD3-V1151I mice created by CRISPR were injected with ADN for direct fluorescence reflectance imaging of CM autophagy, and echo for cardiac function.Results: In 27 HCM human samples, the FHOD3-V1151I genotype was significantly associated with increased p62 protein level, suggesting autophagy impairment, while no change was seen in LC3II/I ratio or FHOD3 (Fig. A,B). Overexpressing FHOD3-V1151I in H9C2s increased p62 and decreased ADN signal (Fig. C,D) compared to FHOD3 WT, indicating less autophagolysosome activity. Interestingly, autophagy activation by rapamycin or fasting restored the ADN signal (Fig. D). ADN imaging revealed significant reduction in CM autophagy in heterozygous FHOD3-V1151I mice, compared to WT controls (n=8, Fig. E,F), while no cardiac dysfunction was observed.Conclusions:In vivo ADN imaging reveals altered autophagy mediated by FHOD3-V1151I. Autophagy activation, quantifiable by ADN, reverses the early p62-mediated autophagy impairment, and may be therapeutic for cardiomyopathy.Download figureDownload PowerPointAuthor Disclosures: L. Wei: None. H.K. Bowditch: None. S.A. Ding: None. S. Weng: None. C. Mekkaoui: None. D.E. Sosnovik: None. R.M. Blanton: None. G.S. Huggins: None. H.H. Chen: None.Key Words: Autophagy; Cardiac imaging; Cardiomyopathy; Hypertrophic cardiomyopathy; Cardiovascular therapeutics18623High-Throughput Phenotypic Screening Using Induced Pluripotent Stem Cell Derived Cardiomyocytes Identifies Compounds That Rescue Genetic Dilated CardiomyopathyIsaac Perea-Gil, Maricela Prado, Arne A Bruyneel, Wesley L McKeithan, Dries A Feyen, Pooja Nair, Mark Mercola, Ioannis Karakikes; Stanford Cardiovascular Institute, Stanford Univ Sch of Medicine, Palo Alto, CAIntroduction: Familial dilated cardiomyopathy (DCM) is a leading cause of heart failure. To date, there is still a large gap in our understanding of the molecular events and signaling pathways that lead from a mutation to diverse disease phenotypes and disease-modifying therapies are lacking. The development of induced pluripotent stem cell (iPSC) technology has enables new opportunities to identify disease-modulating therapeutics and empowers comparatively rapid drug screening for human genetic diseases such as DCM.Methods: iPSCs were generated from three DCM patients harboring a pathogenic mutation in the TNNT2 gene (p. Arg173Trp; TNNT2R173W) and differentiated towards cardiomyocytes (iPSC-CMs). We performed a primary phenotypic screen using high-throughput contractility assays in iPSC-CMs monolayers, and further validated our finding at the single cell and 3D engineered heart tissue levels. Results: We tested a small molecule library of 200 well-characterized protein kinase inhibitors and identified two compounds that rescued the contractile deficit of TNNT2R173W iPSC-CMs. We pursued two hits for further studies and demonstrated that this two kinase inhibitors when combined provided a synergistic effect.Conclusions: Here we determined the feasibility of performing a primary phenotypic screen in DCM iPSC-CMs and demonstrated that small-molecule discovery using an iPSC-based disease model can identify candidate drugs for potential therapeutic intervention. The identification of compounds that increase contractility in DCM iPSC-CMs could yield novel therapies for genetic DCM.Author Disclosures: I. Perea-Gil: None. M. Prado: None. A.A. Bruyneel: None. W.L. McKeithan: None. D.A. Feyen: None. P. Nair: None. M. Mercola: None. I. Karakikes: None.Key Words: Stem cells; Cardiomyopathy; Drugs; Molecular biology; Contractility19411Small Molecule Inhibitors of p300 Acetyltransferase Activity Reverse Hypertension-induced Cardiac FibrosisTianjiao Sun, Rahul Rai, Veronica Ramirez, Elizabeth Lux, Mesut Eren, Douglas Vaughan, Asish Ghosh; NORTHWESTERN UNIVERSITY, Chicago, ILBackground: Heart disease is the leading cause of all disease-related deaths worldwide. Sustained high blood pressure causes cardiac hypertrophy and myocardial fibrosis, leading to loss of myocardial elasticity and heart failure. Previously, we demonstrated that Type I collagen, major contributor in organ fibrogenesis, is epigenetically regulated by acetyltransferase p300 (ATp300). More recently, we showed that L002, a potent inhibitor of p300, prevents hypertension-induced cardiac hypertrophy and fibrogenesis. Here we tested the efficacies of two p300 AT inhibitors, L002 and C646, in reversing hypertension-induced cardiac fibrogenesis.Methods: High blood pressure was induced by minipump-mediated infusion of Angiotensin II (Ang II) for 4 weeks. Saline-infused mice were used as control. After first 2 weeks of Ang II infusion and initiation of hypertension, mice were then treated with DMSO (Group 2), C646 (Group 3), L002 (Group 4) for the next 2 weeks. Control mice infused with Saline were treated with DMSO (Group 1). Drugs were delivered every 72 hours by intraperitoneal injection. Blood pressures were recorded after weeks 2 and 4 using tail-cuff method, and echocardiography was undertaken after week 4. After 4 weeks, hearts were collected and processed for histochemical and biochemical analysis.Results: Ang II significantly induced blood pressure, cardiac hypertrophy and myocardial fibrosis as expected. Post-treatment of mice with L002 reversed hypertension-induced cardiac hypertrophy and myocardial fibrosis as evidenced by significant reduction in hypertrophy of left ventricular wall and myocardial collagen deposition. With C646, reduction in cardiac hypertrophy and myocardial fibrosis was less pronounced than L002. Biochemical analysis also revealed that posttreatment of hypertensive mice with p300 inhibitor leads to decreased myofibroblast differentiation in hypertensive hearts compared to hypertensive hearts without drug treatment.Conclusion: Our results demonstrate that small molecule inhibitors of p300 AT activity effectively reverse hypertension-induced myofibroblast differentiation and cardiac fibrogenesis, and confirm p300 as a druggable target for hypertension-induced cardiac pathologies.This research has received full or partial funding support from the American Heart Association.Author Disclosures: T. Sun: None. R. Rai: None. V. Ramirez: None. E. Lux: None. M. Eren: None. D. Vaughan: None. A. Ghosh: None.Key Words: Hypertension; Cardiac hypertrophy; Extracellular matrix; Fibrosis; Epigenetics19719Adult Deficiency of Cardiac ULK1, but not ULK2, Leads to Robust Mitochondrial Dysfunction, Dilated Cardiomyopathy and Early DeathMatthew P Harris, Cole T Cochran, Jordan D Fuqua, Ana Kronemberger, Vitor A Lira; Univ of Iowa, Iowa City, IAAutophagy is a conserved cellular process for degrading dysfunctional cellular organelles and long-lived proteins. Insufficient autophagy is a common feature of obesity, neurodegenerative diseases, type 2 diabetes, and cardiomyopathies. Unc-51 like autophagy activating kinases 1 and 2 (ULK1 and ULK2) are thought to play a redundant role in stimulating autophagy initiation but the functional significance of these two proteins in the heart remains unclear. qRT-PCR analysis revealed that Ulk1 and Ulk2 are expressed at ~250mRNA copies/ug of total RNA in the heart. To delineate the functions of these proteins in the heart, inducible ULK1 and ULK2 heart-specific knockout mice (i.e., ULK1ihKO and ULK2ihKO) were developed using the αMHC-MerCreMer/LoxP system. At 8 weeks of age ULK1ihKO and ULK2ihKO mice were injected intraperitoneally with 30 mg/kg of tamoxifen 3 consecutive days, which was sufficient to induce a 50% reduction in cardiac Ulk1 and Ulk2 mRNA, respectively. Deletion of ULK1 led to premature death in 55% of male and 30% of female mice within 9 days from the beginning of tamoxifen administration, cardiac hypertrophy (i.e., increased heart weight/tibia length and expression of fetal genes), and impaired cardiac function, specifically more than a two-fold increase in end-diastolic volume and a mean ejection fraction of 22%. These findings are consistent with a dilated cardiomyopathy phenotype leading to heart failure in ULK1ihKO mice. ULK2ihKO mice conversely experienced no premature death and maintained normal cardiac structure and function. Further biochemical analysis showed that ULK1 deficiency also led to an accumulation of LC3 I and II, p62, NBR1, and ubiquitin, suggesting an overall impairment in autophagy. Additionally, ULK1ihKO mice developed significant impairments in pyruvate/malate and palmitoyl+carnitine/malate driven mitochondrial respiration coupled with reduced expression of MTCO1 (i.e., a subunit of the complex IV in the Electron Transport Chain). These results demonstrate that ULK1 and ULK2 have independent roles in cardiac muscle, and that ULK1 is essential to preserve mitochondrial and cardiac contractile function at least in part by maintaining basal autophagy in the heart.This research has received full or partial funding support from the American Heart Association.Author Disclosures: M.P. Harris: None. C.T. Cochran: None. J.D. Fuqua: None. A. Kronemberger: None. V.A. Lira: None.Key Words: Autophagy; Mitochondria; CardiomyopathyLate-Breaking Basic Science19731Splenic Cd169+ Marginal-zone Metallophilic Macrophages Are Required For Wound Healing And Resolution Of Inflammation After Myocardial InfarctionMohamed Ameen Ismahil1, Shyam Bansal1, Bindiya Patel1, Tariq Hamid1, Guihua Zhou1, Gregg Rokosh1, Sumanth D Prabhu2; 1Univ of Alabama at Birmingham, Birmingham, AL, 2Univ of Alabama at Birmingham and Med Service, VAMC, Birmingham, ALIn mice, Ly6Chi monocytes originating from the bone marrow and spleen contribute importantly to inflammation and wound healing after acute myocardial infarction (MI). Beyond Ly6Chi monocytes, the spleen also contains macrophage populations specialized in both efferocytosis and immune tolerance. These include CD169+Tim4+ marginal zone (MZ) metallophilic macrophages (MMMs); however, their role in post-MI repair is entirely unknown. We hypothesized that splenic CD169+ MMMs infiltrate the acutely infarcted heart and play an essential role in wound healing post-MI. In adult C57BL/6 mice, CD169+Tim4+ phagocytes were readily identified in the splenic MZ and the circulation. In the blood, they were predominantly Ly6Clow cells (~50% of total non-classical Ly6Clow monocytes), originated in large part from the spleen (~50% reduction in splenectomized [SPX]

GW29-e1456 The TIR/BB-loop mimetic AS-1 prevents Ang II-induced hypertensive cardiac hypertrophy via modulation of miRNA-143

Untreated pathological cardiac hypertrophy, which can be caused by sustained systemic hypertension, may lead to heart failure. The purpose of this study is to determine whether AS-1 had attenuating effects on hypertension-induced cardiac hypertrophy, and whether this process was mediated by the

New Insights in Cardiac β-Adrenergic Signaling During Heart Failure and Aging.

Heart failure (HF) has become increasingly common within the elderly population, decreasing their survival and overall quality of life. In fact, despite the improvements in treatment, many elderly people suffer from cardiac dysfunction (HF, valvular diseases, arrhythmias or hypertension-induced cardiac hypertrophy) that are much more common in an older fragile heart. Since β-adrenergic receptor (β-AR) signaling is abnormal in failing as well as aged hearts, this pathway is an effective diagnostic and therapeutic target. Both HF and aging are characterized by activation/hyperactivity of various neurohormonal pathways, the most important of which is the sympathetic nervous system (SNS). SNS hyperactivity is initially a compensatory mechanism to stimulate contractility and maintain cardiac output. Unfortunately, this chronic stimulation becomes detrimental and causes decreased cardiac function as well as reduced inotropic reserve due to a decrease in cardiac β-ARs responsiveness. Therapies which (e.g., β-blockers and physical activity) restore β-ARs responsiveness can ameliorate cardiac performance and outcomes during HF, particularly in older patients. In this review, we will discuss physiological β-adrenergic signaling and its alterations in both HF and aging as well as the potential clinical application of targeting β-adrenergic signaling in these disease processes.

Abstract 269: RBM20 Knockout Ameliorates Angiotensin II Induced Hypertension and Cardiac Hypertrophy

Introduction: RNA binding motif 20 (RBM20) is a muscle specific splicing factor that has been implicated in heart failure (HF). RBM20 regulates mRNA splicing of titin, a giant muscle protein that is expressed in cardiac and smooth muscles and plays a major role in passive stiffness of them. RBM20 knockout (KO) results in less myocardial stiffness by inducing large titin isoform expression. Hence, we hypothesize that RBM20 decreases arterial stiffness through large titin isoform expression, and thus reduces blood pressure (BP) in hypertension. The aim of this study was to investigate whether RBM20 could be a therapeutic target to reduce BP in patients with hypertension and prevent HF progression. Methods: Male wild type (WT) (Sprague-Dawley х Brown Norway) and Rbm20 KO rats (n=10 each) were subcutaneously implanted with osmotic mini-pump to continuously release angiotensin II (Ang II) at a rate of 400 ng/kg/min for 28 days. BP was measured by noninvasive tail-cuff system weekly. Pulse wave velocity (PWV) was measured by Doppler system. Cardiac remodeling was evaluated by echocardiography. Biochemistry and histological analyses were performed on aorta and heart tissues. Results: Larger titin isoform was increased and no difference of elastin and collagen expression was observed in RBM20 KO blood vessels when compared to WT. Basal BPs were the same in WT and KO rats (diastolic BP, KO 91.75 ± 1.83 vs. WT 94.33±1.88 mmHg; systolic BP, KO 127.6 ± 0.97 vs. WT 128.0 ± 1.35 mmHg). Ang II increased BP in both WT and KO rats, but KO had a significantly lower BP than WT (diastolic BP, KO 141.7 ± 5.00 vs. WT 182.0±4.84 mmHg; systolic BP, KO 195.4 ± 3.671 vs. WT 226.4 ± 3.093 mmHg, P&lt;0.0001). PWV is lower in KO rats than in WT (KO 4.035 ± 0.21 mm/s vs. WT 5.128±0.37 mm/s, P&lt;0.05). Cardiac hypertrophy was developed in both WT and KO hearts treated with Ang II, but it was alleviated in the KO heart (left ventricular wall, KO 0.324 ± 0.01 cm vs. WT 0.368 ± 0.013 cm, P&lt;0.05). Conclusions: RBM20 KO reduces arterial stiffness through increased larger titin isoform expression, decreases Ang II-induced hypertension, and prevents HF progression. These findings suggest that RBM20 could be a potential novel target for the treatment of hypertension and hypertension-induced cardiac hypertrophy.

Nitrite exerts antioxidant effects, inhibits the mTOR pathway and reverses hypertension-induced cardiac hypertrophy.

Cardiac hypertrophy is a common consequence of chronic hypertension and leads to heart failure and premature death. The anion nitrite is now considered as a bioactive molecule able to exert beneficial cardiovascular effects. Previous results showed that nitrite attenuates hypertension-induced increases in reactive oxygen species (ROS) production in the vasculature. Whether antioxidant effects induced by nitrite block critical signaling pathways involved in cardiac hypertrophy induced by hypertension has not been determined yet. The Akt/mTOR signaling pathway is responsible to activate protein synthesis during cardiac remodeling and is activated by increased ROS production, which is commonly found in hypertension. Here, we investigated the effects of nitrite treatment on cardiac remodeling and activation of this hypertrophic signaling pathway in 2 kidney-1 clip (2K1C) hypertension. Sham and 2K1C rats were treated with oral nitrite at 1 or 15 mg/kg for four weeks. Nitrite treatment (15 mg/kg) reduced systolic blood pressure and decreased ROS production in the heart tissue from hypertensive rats. This nitrite dose also blunted hypertension-induced activation of mTOR pathway and cardiac hypertrophy. While the lower nitrite dose (1 mg/kg) did not affect blood pressure, it exerted antioxidant effects and tended to attenuate mTOR pathway activation and cardiac hypertrophy induced by hypertension. Our findings provide strong evidence that nitrite treatment decreases cardiac remodeling induced by hypertension as a result of its antioxidant effects and downregulation of mTOR signaling pathway. This study may help to establish nitrite as an effective therapy in hypertension-induced cardiac hypertrophic remodeling.

Temporal changes in cardiac oxidative stress, inflammation and remodeling induced by exercise in hypertension: Role for local angiotensin II reduction.

Exercise training reduces renin-angiotensin system (RAS) activation, decreases plasma and tissue oxidative stress and inflammation in hypertension. However, the temporal nature of these phenomena in response to exercise is unknown. We sought to determine in spontaneously hypertensive rats (SHR) and age-matched WKY controls the weekly effects of training on blood pressure (BP), plasma and left ventricle (LV) Ang II and Ang-(1–7) content (HPLC), LV oxidative stress (DHE staining), gene and protein expression (qPCR and WB) of pro-inflammatory cytokines, antioxidant enzymes and their consequence on hypertension-induced cardiac remodeling. SHR and WKY were submitted to aerobic training (T) or maintained sedentary (S) for 8 weeks; measurements were made at weeks 0, 1, 2, 4 and 8. Hypertension-induced cardiac hypertrophy was accompanied by acute plasma Ang II increase with amplified responses during the late phase of LV hypertrophy. Similar pattern was observed for oxidative stress markers, TNF alpha and interleukin-1β, associated with cardiomyocytes’ diameter enlargement and collagen deposition. SHR-T exhibited prompt and marked decrease in LV Ang II content (T1 vs T4 in WKY-T), normalized oxidative stress (T2), augmented antioxidant defense (T4) and reduced both collagen deposition and inflammatory profile (T8), without changing cardiomyocytes’ diameter and LV hypertrophy. These changes were accompanied by decreased plasma Ang II content (T2-T4) and reduced BP (T8). SHR-T and WKY-T showed parallel increases in LV and plasma Ang-(1–7) content. Our data indicate that early training-induced downregulation of LV ACE-AngII-AT1 receptor axis is a crucial mechanism to reduce oxidative/pro-inflammatory profile and improve antioxidant defense in SHR-T, showing in addition this effect precedes plasma RAS deactivation.