Ang II-induced Vascular Remodeling Research Articles

ZFP36 Regulates Vascular Smooth Muscle Contraction and Maintains Blood Pressure.

Hypertension remains a major risk factor for cardiovascular diseases, but the underlying mechanisms are not well understood. Zinc finger protein 36 (ZFP36) is an RNA-binding protein that regulates mRNA stability by binding to adenylate-uridylate-rich elements in the mRNA 3'-untranslated region. This study reveals that ZFP36 expression is highly elevated in the arteries of hypertensive patients and rodents. In cultured vascular smooth muscle cell (VSMC), angiotensin II (AngII) activates poly (ADP-ribose) polymerases1 (PARP1) to stimulate Zfp36 expression at the transcriptional level. VSMC-specific ZFP36 deletion reduces vessel contractility and blood pressure levels in mice. Mechanistically, ZFP36 regulates G protein-coupled receptors (GPCRs)-mediated increases in intracellular calcium levels through impairing the mRNA stability of regulator of G protein signaling 2 (RGS2). Moreover, the VSMC-specific ZFP36 deficiency attenuates AngII-induced hypertension and vascular remodeling in mice. AAV-mediated ZFP36 knockdown ameliorates spontaneous hypertension in rats. These findings elucidate that ZFP36 plays an important role in the regulation of smooth muscle contraction and blood pressure through modulating RGS2 expression. ZFP36 inhibition may represent a new therapeutic strategy for the treatment of hypertension.

Endothelial FOSL1 drives angiotensin II-induced myocardial injury via AT1R-upregulated MYH9.

Vascular remodeling represents a pathological basis for myocardial pathologies, including myocardial hypertrophy and myocardial infarction, which can ultimately lead to heart failure. The molecular mechanism of angiotensin II (Ang II)-induced vascular remodeling following myocardial infarction reperfusion is complex and not yet fully understood. In this study, we examined the effect of Ang II infusion on cardiac vascular remodeling in mice. Single-cell sequencing showed Ang IIinduced cytoskeletal pathway enrichment and that FOS like-1 (FOSL1) affected mouse cardiac endothelial dysfunction by pseudotime analysis. Myosin heavy chain 9 (MYH9) was predominantly expressed in primary cardiac endothelial cells. The Ang II type I receptor blocker telmisartan and the protein kinase C inhibitor staurosporine suppressed Ang II-induced upregulation of MYH9 and FOSL1 phosphorylation in human umbilical vein endothelial cells. Silencing MYH9 abolished Ang II-mediated inhibition of angiogenesis in human umbilical vein endothelial cells, and attenuated AngII-induced vascular hyperpermeability. We found that FOSL1 directly bound to the MYH9 promoter and thus activated transcription of MYH9 by the dual luciferase reporter and chromatin immunoprecipitation assays, leading to vascular dysfunction. In vivo, 6 weeks after injecting adeno-associated virus-ENT carrying the TEK tyrosine kinase (tie) promoter-driven short hairpin RNA for silencing FOSL1 (AAV-tie-shFOSL1), cardiac function represented by the ejection fraction and fractional shortening was improved, myocardial fibrosis was decreased, protein levels of phosphorylated FOSL1, MYH9, and collagen type I alpha were reduced, and cardiac vascular density was recovered in mice with endothelial Fosl1-specific knockdown in Ang II-infused mice. In ischemia-reperfusion mice, AAV-shFosl1 mice had a reduced infarct size and preserved cardiac function compared with control AAV mice. Our findings suggest a critical role of the FOSL1/MYH9 axis in hindering Ang II-induced vascular remodeling, and we identified FOSL1 as a potential therapeutic target in endothelial cell injuries induced by myocardial ischemia-reperfusion.

Endothelial deubiquinatase YOD1 mediates Ang II-induced vascular endothelial-mesenchymal transition and remodeling by regulating β-catenin.

Hypertension is a prominent contributor to vascular injury. Deubiquinatase has been implicated in the regulation of hypertension-induced vascular injury. In the present study we investigated the specific role of deubiquinatase YOD1 in hypertension-induced vascular injury. Vascular endothelial endothelial-mesenchymal transition (EndMT) was induced in male WT and YOD1-/- mice by administration of Ang II (1 μg/kg per minute) via osmotic pump for four weeks. We showed a significantly increased expression of YOD1 in mouse vascular endothelial cells upon Ang II stimulation. Knockout of YOD1 resulted in a notable reduction in EndMT in vascular endothelial cells of Ang II-treated mouse; a similar result was observed in Ang II-treated human umbilical vein endothelial cells (HUVECs). We then conducted LC-MS/MS and co-immunoprecipitation (Co-IP) analyses to verify the binding between YOD1 and EndMT-related proteins, and found that YOD1 directly bound to β-catenin in HUVECs via its ovarian tumor-associated protease (OTU) domain, and histidine at 262 performing deubiquitination to maintain β-catenin protein stability by removing the K48 ubiquitin chain from β-catenin and preventing its proteasome degradation, thereby promoting EndMT of vascular endothelial cells. Oral administration of β-catenin inhibitor MSAB (20 mg/kg, every other day for four weeks) eliminated the protective effect of YOD1 deletion on vascular endothelial injury. In conclusion, we demonstrate a new YOD1-β-catenin axis in regulating Ang II-induced vascular endothelial injury and reveal YOD1 as a deubiquitinating enzyme for β-catenin, suggesting that targeting YOD1 holds promise as a potential therapeutic strategy for treating β-catenin-mediated vascular diseases.

DNA-dependent protein kinase catalytic subunit (DNA-PKcs) drives angiotensin II-induced vascular remodeling through regulating mitochondrial fragmentation

BackgroundDNA-dependent protein kinase catalytic subunit (DNA-PKcs) is a novel instigator for mitochondrial dysfunction, and plays an important role in the pathogenesis of cardiovascular diseases. However, the role and mechanism of DNA-PKcs in angiotensin II (Ang II)-induced vascular remodeling remains obscure. MethodsRat aortic smooth muscle cells (SMC) and VSMC-specific DNA-PKcs knockout (DNA-PKcsΔVSMC) mice were employed to examine the role of DNA-PKcs in vascular remodeling and the underlying mechanisms. Blood pressure of mice was monitored using the tail-cuff and telemetry methods. The role of DNA-PKcs in vascular function was evaluated using vascular relaxation assessment. ResultsIn the tunica media of remodeled mouse thoracic aortas, and renal arteries from hypertensive patients, elevated DNA-PKcs expression was observed along with its cytoplasmic translocation from nucleus, suggesting a role for DNA-PKcs in vascular remodeling. We then infused wild-type (DNA-PKcsfl/fl) and DNA-PKcsΔVSMC mice with Ang II for 14 days to establish vascular remodeling, and demonstrated that DNA-PKcsΔVSMC mice displayed attenuated vascular remodeling through inhibition of dedifferentiation of VSMCs. Moreover, deletion of DNA-PKcs in VSMCs alleviated Ang II-induced vasodilation dysfunction and hypertension. Mechanistic investigations denoted that Ang II-evoked rises in cytoplasmic DNA-PKcs interacted with dynamin-related protein 1 (Drp1) at its TQ motif to phosphorylate Drp1S616, subsequently promoting mitochondrial fragmentation and dysfunction, as well as reactive oxygen species (ROS) production. Treatment of irbesartan, an Ang II type 1 receptor (AT1R) blocker, downregulated DNA-PKcs expression in VSMCs and aortic tissues following Ang II administration. ConclusionOur data revealed that cytoplasmic DNA-PKcs in VSMCs accelerated Ang II-induced vascular remodeling by interacting with Drp1 at its TQ motif and phosphorylating Drp1S616 to provoke mitochondrial fragmentation. Maneuvers targeting DNA-PKcs might be a valuable therapeutic option for the treatment of vascular remodeling and hypertension.

Abstract P237: Bainiku-ekisu Attenuates Cardiac Remodeling In Angiotensin Ii-infused Mice

A fruit of the Prunus mume is a traditional food in Japan. Recently, bainiku-ekisu, an infused juice concentrate of Japanse Prunus mume , is attracting attention as a health promoting supplement. Angiotensin II (AngII) plays a central role in development of hypertension. It has been reported that bainiku-ekisu treatment attenuates the growth-promoting signaling induced by AngII in vascular smooth muscle cells. However, whether bainiku-ekisu has any effect on an animal model of hypertension remains unknown. Therefore, this study was designed to explore the potential anti-hypertensive benefit of bainiku-ekisu utilizing a mouse model of hypertension with AngII infusion. 8- to 10-week-old male C57BL6 mice were randomly divided into four groups and infused with Ang II (1 μg/kg/min) for 2 weeks via osmotic mini-pump or sham-operated, and given 1% BE containing water (BEW) or normal water (control) for 2 weeks. Blood pressure was evaluated every other day by tail cuff measurement and at 2 weeks by telemetry. Cardiac hypertrophy was assessed by heart-to-body weight ratio. After 2 weeks, mice were euthanized, and the aorta and heart collected. Extracted aortas and hearts were fixed and used for histological studies to evaluate vascular remodeling. Increase in heart-to-body weight ratios by Ang II were unaltered by BEW. Aortic medial hypertrophy was observed in control mice (n=5) after 2 weeks of Ang II infusion, which was attenuated in BEW group (96 μm vs. 71 μm, respectively, p<0.01). Control mice with angiotensin II infusion showed cardiac matrix deposition, which was attenuated in BEW group. In addition, attenuation of hypertension was observed in Ang II-infused mice with BEW treatment. We also observed attenuation of protein synthesis induced by AngII with BE incubation in cultured aortic VSMC. In conclusion, BEW prevented Ang II-induced vascular remodeling and hypertension. Potential cardiovascular health benefit to taking BE as a functional food should be further studied.

Abstract P315: Angiotensin Ii Type 1a Receptor Expressed In Smooth Muscle Cells Is Required For Vascular Remodeling In Mice Infused With Angiotensin II

Angiotensin II (AngII) type 1A (AT 1A ) receptors play a critical role in hypertension and cardiovascular remodeling in mice infused with AngII. Although vascular remodeling, a significant contributor to organ damage, occurs concurrently with hypertension in AngII infused mice, the contribution of smooth muscle AT 1A in this process remains unexplored. Accordingly, it is hypothesized that smooth muscle AT 1A receptors exclusively contribute to both medial thickening and adventitial fibrosis regardless of the presence of hypertension. 1 μg/kg/min AngII was infused for 2 weeks in two distinct AT 1A receptor silenced mice, knock-in Tagln -mediated constitutive smooth muscle AT 1A receptor silenced mice and Myh11 -mediated inducible smooth muscle AT 1A silenced mice for evaluation of hypertensive cardiovascular remodeling. Medial thickness, adventitial collagen deposition and immune cell infiltration in aorta were increased in control mice but not in both smooth muscle AT 1A receptor silenced mice. Coronary arterial perivascular fibrosis in response to AngII infusion was also attenuated in both AT 1A receptor silenced mice. AngII-induced cardiac hypertrophy was attenuated in constitutive smooth muscle AT 1A receptor silenced mice. However, AngII-induced cardiac hypertrophy and hypertension were not altered in inducible smooth muscle AT 1A receptor silenced mice (SBP control 148 vs knockout 149 mmHg). In conclusion, smooth muscle AT 1A receptors mediate AngII-induced vascular remodeling including medial hypertrophy and inflammatory perivascular fibrosis regardless of the presence of hypertension. Our data suggest an independent etiology of blood pressure elevation and hypertensive vascular remodeling in response to AngII.

Vascular Smooth Muscle Cells Specific Deletion of Angiopoietin-Like Protein 8 Prevents AngII-Promoted Hypertension and Cardiovascular Hypertrophy.

Angiopoietin-like protein 8 (ANGPTL8) plays important roles in lipid metabolism, glucose metabolism, inflammation, and cell proliferation and migration. Clinical studies have indicated that circulating ANGPTL8 concentrations are increased in patients with hypertension and positively associated with blood pressure. ANGPTL8 deficiency ameliorates blood pressure in mice treated with chronic intermittent hypoxia. Currently, little is known regarding the pathophysiological role of vascular smooth muscle cell (VSMC)-derived ANGPTL8 in hypertension and hypertensive cardiovascular remodelling. Circulating ANGPTL8 concentrations, as determined by enzyme-linked immunosorbent assay, were significantly higher in hypertensive patients than in controls (524.51 ± 26.97 vs 962.92 ± 15.91 pg/ml; P < 0.001). In hypertensive mice (angiotensin II [AngII] treatment for 14 days) and spontaneously hypertensive rats, ANGPTL8 expression was increased and predominantly located in VSMCs. In AngII-treated mice, systolic and diastolic blood pressure in Tagln-Cre-ANGPTL8fl/fl mice were approximately 15-25 mmHg lower than that in ANGPTL8fl/fl mice. AngII-induced vascular remodelling, vascular constriction, and increased expression of cell markers of proliferation (PCNA and Ki67) and migration (MMP-2 and MMP-9) were strikingly attenuated in Tagln-Cre-ANGPTL8fl/fl mice compared with ANGPTL8fl/fl mice. Furthermore, the AngII-induced increase in the heart size, heart weight, heart/body weight ratio, cardiomyocyte cross-sectional area, and collagen deposition was ameliorated in Tagln-Cre-ANGPTL8fl/fl mice compared with ANGPTL8fl/fl mice. In rat artery smooth muscle cells, ANGPTL8-short hairpin RNA decreased intracellular calcium levels and prevented AngII-induced proliferation and migration through the PI3K-Akt pathway, as shown using LY294002 (inhibitor of PI3K) and Akt inhibitor VIII. This study suggests that ANGPTL8 in VSMCs plays an important role in AngII-induced hypertension and associated cardiovascular remodelling. ANGPTL8 may be a novel therapeutic target against pathological hypertension and hypertensive cardiovascular hypertrophy. This study reveals a novel factor included in hypertension and hypertensive cardiovascular remodeling. We found that VSMC specific deletion of ANGPTL8 could lower blood pressure approximately15-25 mmHg. Besides its role in regulating blood pressure, ANGPTL8 knockout also attenuated cardiovascular remodeling and fibrosis in hypertensive mice. These new findings indicate that ANGPTL8 in VSMC is involved in the regulating of hypertension and associated cardiovascular hypertrophy, thus suggesting that ANGPTL8 might be a new therapeutic target for hypertension and hypertensive cardiovascular remodeling.

Gasdermin D affects aortic vascular smooth muscle cell pyroptosis and Ang II-induced vascular remodeling

Vascular smooth muscle cells (VSMCs) are primarily responsible for vasoconstriction and the regulation of blood pressure1. Pyroptosis, a particular form of regulated cell death, is involved in multiple vascular injuries, including hypertensive vascular dysfunction. This pyroptotic cell death is mediated by the pore-forming protein of Gasdermin D (GSDMD). This study was designed to examine the direct effect of GSDMD on smooth muscle cell pyroptosis and vascular remodeling. Findings revealed that GSDMD was activated in Angiotensin (Ang) II- treated aortas. We then showed that genetic deletion of Gsdmd reduced vascular remodeling and aorta pyroptosis induced by Ang II in vivo. Aberrant expression of GSDMD by recombinant AAV9 virus carrying Gsdmd cDNA aggravated the level of pyroptosis in aortas of Ang II mice. Gain- and loss-of- function analysis further confirmed that GSDMD regulated the pyroptosis of murine aortic vascular smooth muscle cells (MOVAS) in an in vitro model of tumor necrosis factor (TNF)-α treatment, which was achieved by transfecting expressing plasmid or siRNA, respectively. Overall, this study provided evidence supporting the active involvement of GSDMD in smooth muscle cell pyroptosis and Ang II-induced mice vascular injury. This finding lends credence to GSDMD as a potential therapeutic target for hypertensive vascular remodeling via inhibiting pyroptosis.

Severe hypertriglyceridemia caused by Gpihbp1 deficiency facilitates vascular remodeling through increasing endothelial activation and oxidative stress

Hypertriglyceridemia (HTG) is an independent risk factor for atherosclerosis. However, its impact on non-atherosclerotic cardiovascular diseases remains largely unknown. Glycosylphosphatidylinositol anchored high-density lipoprotein binding protein 1 (GPIHBP1) is essential for the hydrolysis of circulating triglycerides and loss of functional GPIHBP1 causes severe HTG. In this study, we used Gpihbp1 knockout (GKO) mice to investigate the potential effects of HTG on non-atherosclerotic vascular remodeling. We compared the aortic morphology and gene expressions between three-month-old and ten-month-old GKO mice and their age-matched wild-type controls. We also conducted similar comparisons between GKO mice and wild-type controls in an angiotensin II (AngII)-induced vascular remodeling model. Our data showed that the intima-media wall of ten-month-old GKO mice but not three-month-olds was significantly thickened compared to wild-type controls. Moreover, ten-month-old GKO mice but not three-month-olds had increased aortic macrophage infiltration and perivascular fibrosis, along with increased endothelial activation and oxidative stress. Similarly, the AngII-induced vascular remodeling, as well as endothelial activation and oxidative stress, were also exacerbated in the GKO mice compared to wild-type controls. In conclusion, we demonstrated that severe HTG caused by Gpihbp1 deficiency could facilitate the onset and progression of non-atherosclerotic vascular remodeling through endothelial activation and oxidative stress in mice.

Mouse endothelial OTUD1 promotes angiotensin II-induced vascular remodeling by deubiquitinating SMAD3.

Understanding the molecular mechanisms of pathological vascular remodeling is important for treating cardiovascular diseases and complications. Recent studies have highlighted a role of deubiquitinases in vascular pathophysiology. Here, we investigate the role of a deubiquitinase, OTUD1, in angiotensin II (Ang II)-induced vascular remodeling. We detect upregulated OTUD1 in the vascular endothelium of Ang II-challenged mice and show that OTUD1 deletion attenuates vascular remodeling, collagen deposition, and EndMT. Conversely, OTUD1 overexpression aggravates these pathological changes both invivo and invitro. Mechanistically, SMAD3 is identified as a substrate of OTUD1 using co-immunoprecipitation followed by LC-MS/MS. We find that OTUD1 stabilizes SMAD3 and facilitates SMAD3/SMAD4 complex formation and subsequent nuclear translocation through both K48- and K63-linked deubiquitination. OTUD1-mediated SMAD3 activation regulates transcription of genes involved in vascular EndMT and remodeling in HUVECs. Finally, SMAD3 inhibition reverses OTUD1-promoted vascular remodeling. Our findings demonstrate that endothelial OTUD1 promotes Ang II-induced vascular remodeling by deubiquitinating SMAD3. We identify SMAD3 as a target of OTUD1 and propose OTUD1 as a potential therapeutic target for diseases related to vascular remodeling.

Attenuation of Smooth Muscle Cell Phenotypic Switching by Angiotensin 1-7 Protects against Thoracic Aortic Aneurysm.

Thoracic aortic aneurysm (TAA) involves extracellular matrix (ECM) remodeling of the aortic wall, leading to reduced biomechanical support with risk of aortic dissection and rupture. Activation of the renin-angiotensin system, and resultant angiotensin (Ang) II synthesis, is critically involved in the onset and progression of TAA. The current study investigated the effects of angiotensin (Ang) 1-7 on a murine model of TAA. Male 8-10-week-old ApoEKO mice were infused with Ang II (1.44 mg/kg/day) and treated with Ang 1-7 (0.576 mg/kg/day). ApoEKO mice developed advanced TAA in response to four weeks of Ang II infusion. Echocardiographic and histological analyses demonstrated increased aortic dilatation, excessive structural remodelling, perivascular fibrosis, and inflammation in the thoracic aorta. Ang 1-7 infusion led to attenuation of pathological phenotypic alterations associated with Ang II-induced TAA. Smooth muscle cells (SMCs) isolated from adult murine thoracic aorta exhibited excessive mitochondrial fission, oxidative stress, and hyperproliferation in response to Ang II. Treatment with Ang 1-7 resulted in inhibition of mitochondrial fragmentation, ROS generation, and hyperproliferation. Gene expression profiling used for characterization of the contractile and synthetic phenotypes of thoracic aortic SMCs revealed preservation of the contractile phenotype with Ang 1-7 treatment. In conclusion, Ang 1-7 prevented Ang II-induced vascular remodeling and the development of TAA. Enhancing Ang 1-7 actions may provide a novel therapeutic strategy to prevent or delay the progression of TAA.

ANGIOTENSIN 1-7 EXERTS PROTECTIVE EFFECTS IN THORACIC AORTIC ANEURYSM BY ATTENUATING SMOOTH MUSCLE CELL PHENOTYPIC SWITCHING

ANGIOTENSIN 1-7 EXERTS PROTECTIVE EFFECTS IN THORACIC AORTIC ANEURYSM BY ATTENUATING SMOOTH MUSCLE CELL PHENOTYPIC SWITCHING

Abstract P123: Angiotensin Ii Type 1a Receptor Expressed Insmooth Muscle Cells Is Required Forangiotensin Ii-induced Vascular Remodeling But Not For Cardiac Hypertrophy

Angiotensin II Type 1a Receptor (AT1a) has been shown to play a critical role in cardiovascular diseases. We have demonstrated that ADAM17 mediates cardiovascular remodeling induced by angiotensin II (AngII) by using an SM22α Cre reporter, which expresses in smooth muscle cells (SMC) and cardiomyocytes. It is conceivable that AT1 signaling in SMC specifically initiates cardiovascular remodeling, such as hypertrophy and fibrosis. Deficiency of SMC AT1a receptors via endogenous SM22α promoter knock-in (KISMKO) results in diminished hypertension and cardiac hypertrophy induced by AngII. However, we have limited understanding whether SMC AT1a receptors affect vascular fibrosis and cardiac hypertrophy. Thus, this study was designed to elucidate the roles of the SMC AT1a receptor in cardiovascular remodeling using two distinct SMC AT1a receptor deficient mice. One line is the KISMKO, and another line is Tamoxifen inducible SMMHC-Cre AT1aflox/flox mouse (SMMHCKO) silencing in SMC but not cardiac myocytes. 8 to 12-week-old male mice were infused with AngII (1 μg/kg/min) for 2 weeks. Cardiac hypertrophy was assessed by heart-to-body weight ratios and found to be reduced in KISMKO mice compared with control mice (6.04 mg/g versus 4.89 mg/g, p=0.032), whereas ratios were not altered in SMMHCKO mice (5.31 mg/g versus 5.47 mg/g, p=0.941). Histological assessment demonstrated that perivascular fibrosis in coronary arteries was increased in control mice and attenuated in both KISMKO and SMMHCKO mice (1.27 vs. 0.22, p&lt;0.0001 and 0.70 vs. 0.16, p&lt;0.0001, respectively.). Medial thickness of descending aorta was increased in control mice and these phenotypic changes were attenuated in both KISMKO and SMMHCKO mice (97 vs. 56 μm, p&lt;0.0001 and 98 vs. 74 μm, p&lt;0.0001, respectively.). In conclusion, SMC AT1a receptors could mediate AngII-induced vascular remodeling including perivascular fibrosis but not cardiac hypertrophy. Cardiac myocyte AT1a appears critical for cardiac hypertrophy. Our data together with a past manuscript demonstrate a protective effect of SMC AT1a silencing in overall vascular remodeling. However, the exact relationship between hypertension and vascular remodeling remains to be elucidated.

Resolvin D2 prevents cardiovascular damage in angiotensin II-induced hypertension

Introduction: Vascular functional and structural alterations induced by hypertension are greatly influenced by low- grade chronic inflammation. Resolution of inflammation is orchestrated by specialized lipid pro-resolving mediators (SPMs), which derive from n3 fatty acids (PUFAs). Previous evidence suggest that SPM prevent vascular damage in several pathological situations including atherosclerosis or vascular restenosis. Among SPMs, resolvins (Rv) seem to have beneficial effects in some cardiovascular pathologies, but little is known about their effect on cardiovascular damage in hypertension. Objective: The aim of this study was to evaluate the effects of resolvin D2 (RvD2) in blood pressure and cardiovascular damage associated with hypertension. Material and methods: aorta, mesenteric resistance arteries (MRA), heart and peritoneal macrophages were taken from C57BL/6J mice, infused or not with angiotensin II (AngII; 1,44mg/kg/day; for 14 days) in presence or absence of RvD2 (100ng/mice, every second day, started before AngII infusion). Blood pressure was measured by tail-cuff plethysmography. Cardiac and vascular function and structure were studied with wire and pressure myographs, confocal microscopy, histological staining, and echocardiography. Circulating leucocyte were analyzed by flow cytometry and macrophages behavior by electrophysiology. Gene expression was analyzed with RT-PCR. Results: Aorta or heart from AngII-infused mice showed altered expression of enzymes and receptors involved in SPMs biosynthesis and signaling. We also observed a downregulation of SPMs in heart tissues from these mice including 17R-RvD1 and RvE3. Treatment with RvD2 partially prevented the increase in blood pressure and in the content of circulating immune cells induced by AngII. RvD2 treatment also improved cardiac hypertrophy, fibrosis and dysfunction. Moreover, RvD2 treatment reduced vascular hypercontractility and endothelial dysfunction induced by AngII likely because of enhanced NO and PGI2 availability. RvD2 normalized AngII-induced vascular remodeling by decreasing media thickness and number of vascular smooth muscle cell, while it did not affect vascular stiffness. Finally, RvD2 reduced aortic and cardiac leukocyte infiltration and shifted macrophage phenotype towards a pro-resolving phenotype. Conclusion: Our data shows that RvD2 treatment limits the cardiovascular alterations induced by hypertension. These findings highlight that activating resolution mechanisms by treatment with RvD2 may represent a novel therapeutic strategy for the treatment of cardiovascular alterations associated to hypertension.

Abstract 348: Angiotensin 1-7 Exerts Protective Effects In Thoracic Aortic Aneurysm By Attenuating Smooth Muscle Cell Phenotypic Switching

Background: Thoracic aortic aneurysm (TAA) involves extracellular matrix (ECM) remodeling of the aortic wall, leading to reduced biomechanical support with risk of aortic dissection and rupture. Elusive pathophysiology of initiation and progression of TAA has hindered efforts to develop pharmacological therapeutic interventions to delay or prevent progressive aortic dilatation. Activation of the renin-angiotensin system, and resultant Angiotensin (Ang) II synthesis, is critically involved in the onset and progression of TAA. The current study investigated the effects of Angiotensin (Ang) 1-7 on a murine model of TAA. Methods &amp; Results: 8-10 weeks old apolipoprotein-deficient mice (ApoEKO) were infused with Ang II (1.44 mg/kg/day) and treated with Ang 1-7 (0.576 mg/kg/day). Echocardiography and histological analyses revealed increased thoracic aortic dilatation, ECM remodeling, perivascular fibrosis, and inflammation in Ang II-treated mice. Infusion of Ang 1-7 led to suppression of Ang II-induced dilatation, remodeling, and inflammation in the thoracic aorta. The immunofluorescence imaging showed reduced α-SMA fluorescence (contractile marker) in vascular smooth muscle cells (VSMCs) of the aortic media indicating phenotypic switching. In response to Ang II, the thoracic VSMCs from ApoEKO mice exhibited phenotypic switching indicated by reduced contractile ( Acta2, Cnn1, Myh11 ) and increased synthetic ( Il-6, Mmp2, Mmp9, Col1a1, Col3a1 ) gene expression. Ki67 staining and flow cytometry analysis showed VSMCs hyperproliferation with Ang II treatment. Ang 1-7 preserved the contractile phenotype of VSMCs and attenuated hyperproliferation. The mitochondrial structure was assessed using MitoTracker Red staining which showed Ang II-induced excessive mitochondrial fission. DHE and MitoSOX Red staining were used to assess the reactive oxygen species (ROS). Ang II-treated thoracic VSMCs demonstrated elevated cellular and mitochondrial ROS generation. Ang 1-7 mitigated Ang II-induced mitochondrial fission and oxidative stress. Conclusion: Ang 1-7 prevented Ang II-induced vascular remodeling and the development of TAA. Enhancing Ang 1-7 actions may provide a novel therapeutic strategy to prevent or delay the progression of TAA.

The role of immunoglobulin E and mast cells in hypertension.

Hypertension is the major cause of cardiovascular diseases and global mortality. Immunoglobulin E (IgE), which plays crucial roles in allergic diseases, has been implicated in the pathogenesis of vascular and cardiac remodelling via its receptor (FcεR1). In this study, we aimed to reveal the role of IgE and FcεR1 in hypertension. Herein, we reported that IgE levels were significantly increased in hypertensive patients as well as in hypertensive mice induced by angiotensin II (Ang II). Ang II-induced vascular remodelling and hypertension were significantly alleviated in FcεR1 genetic knockout mice or in mice treated with anti-IgE monoclonal antibody. Similarly, treatment with omalizumab (a clinical IgE antagonist) also markedly inhibited Ang II-induced hypertension. Furthermore, the cellular contribution of IgE-FcεR1 in hypertension was evaluated in mice with FcεR1 conditional knockout in mast cell (MC), smooth muscle cell (SMC), or endothelial cell (EC). Our data revealed that IgE-mediated hypertension is largely dependent on FcεR1 in MCs but not SMCs and ECs. Finally, RNA-seq and signalling pathway analyses of mouse bone marrow-derived MCs suggested that interleukin 6 (IL-6) is one of critical mediators in IgE-mediated hypertension. IL-6 derived from IgE-stimulated MCs promoted reactive oxygen species production and decreased the levels of phosphorylated endothelial nitric oxide synthase in ECs, leading to endothelial dysfunction. Our findings reveal that IgE contributes to the pathogenesis of hypertension, at least partially through activating the IgE-FcεR1 signalling in MCs. Thus, IgE may represent a new therapeutic target for IgE-mediated hypertension.

Stromal cell-derived factor-1 exerts opposing roles through CXCR4 and CXCR7 in angiotensin II-induced adventitial remodeling

Recent studies have emphasized the role of vascular adventitia inflammation and immune response in hypertension. It has been reported that stromal cell-derived factor-1 (SDF-1) plays various biological functions through its receptors C-X-C motif chemokine receptor 4 (CXCR4) and CXCR7 in tumor growth and tissue repair. However, it is unclear that whether SDF-1/CXCR4/CXCR7 axis is involved in hypertensive vascular remodeling. In the present study, the involvement of SDF-1/CXCR4/CXCR7 axis was evaluated with lentivirus-mediated shRNA of SDF-1 and CXCR7, CXCR4 antagonist AMD3100 and CXCR7 agonist VUF11207 in angiotensin II (AngII)-induced hypertensive mice and in cultured adventitial fibroblasts (AFs). Results showed that AngII infusion markedly increased SDF-1 expressed in vascular adventitia, but not in media and endothelium. Importantly, blockade of SDF-1/CXCR4 axis strikingly potentiated AngII-induced adventitial thickening and fibrosis, as indicated by enhanced collagen I deposition. In contrast, CXCR7 shRNA largely attenuated AngII-induced adventitial thickness and fibrosis, whereas CXCR7 activation with VUF11207 significantly potentiated AngII-induced adventitial thickening and fibrosis. In consistent with these in vivo study, CXCR4 inhibition with AMD3100 and CXCR7 activation with VUF11207 aggravated AngII-induced inflammation, proliferation and migration in cultured AFs. In summary, these results suggested that SDF-1 exerted opposing effects through CXCR4 and CXCR7 in AngII-induced vascular adventitial remodeling.

Low-intensity pulsed ultrasound prevents angiotensin II-induced aortic smooth muscle cell phenotypic switch via hampering miR-17-5p and enhancing PPAR-γ

Vascular events can trigger a pathological phenotypic switch in vascular smooth muscle cells (VSMCs), decreasing and disrupting the plasticity and diversity of vascular networks. The development of novel therapeutic approaches is necessary to prevent these changes. We aimed to investigate the effects and associated mechanisms of low-intensity pulsed ultrasound (LIPUS) irradiation on the angiotensin II (AngII)-induced phenotypic switch in VSMCs. In vivo, AngII was infused subcutaneously for 4 weeks to stimulate vascular remodeling in mice, and LIPUS irradiation was applied for 20min every 2 days for 4 weeks. In vitro, cultured rat aortic VSMCs (RAVSMCs) were pretreated once with LIPUS irradiation for 20min before 48-h AngII stimulation. Our results showed that LIPUS irradiation prevents AngII-induced vascular remodeling of the whole wall artery without discriminating between adventitia and media in vivo and RAVSMC phenotypic switching in vitro. LIPUS irradiation downregulated miR-17-5p expression and upregulated peroxisome proliferator-activated receptor gamma (PPAR-γ) expression. The PPAR-γ activator rosiglitazone could mimic the favorable effects of LIPUS irradiation on AngII-treated RAVSMCs. In contrast, GW9662 could impede the LIPUS-mediated downregulation of RAVSMC proliferation and inflammation under AngII stimulation conditions in vivo and in vitro. Also, the miR-17-5p agomir has the same effects as GW9662 in vitro. Besides, the inhibitory effects of GW9662 against the anti-remodeling effects of LIPUS irradiation in AngII-induced RAVSMCs could be blocked by pretreatment with the miR-17-5p antagomir. Overall, LIPUS irradiation prevents AngII-induced RAVSMCs phenotypic switching through hampering miR-17-5p and enhancing PPAR-γ, suggesting a new approach for the treatment of vascular disorders.

CD38 deficiency alleviates Ang II-induced vascular remodeling by inhibiting small extracellular vesicle-mediated vascular smooth muscle cell senescence in mice

CD38 is the main enzyme for nicotinamide adenine dinucleotide (NAD) degradation in mammalian cells. Decreased NAD levels are closely related to metabolic syndromes and aging-related diseases. Our study showed that CD38 deficiency significantly alleviated angiotensin II (Ang II)-induced vascular remodeling in mice, as shown by decreased blood pressures; reduced vascular media thickness, media-to-lumen ratio, and collagen deposition; and restored elastin expression. However, our bone marrow transplantation assay showed that CD38 deficiency in lymphocytes led to lack of protection against Ang II-induced vascular remodeling, suggesting that the effects of CD38 on Ang II-induced vascular remodeling might rely primarily on vascular smooth muscle cells (VSMCs), not lymphocytes. In addition, we observed that CD38 deficiency or NAD supplementation remarkably mitigated Ang II-induced vascular senescence by suppressing the biogenesis, secretion, and internalization of senescence-associated small extracellular vesicles (SA-sEVs), which facilitated the senescence of neighboring non-damaged VSMCs. Furthermore, we found that the protective effects of CD38 deficiency on VSMC senescence were related to restoration of lysosome dysfunction, particularly with respect to the maintenance of sirtuin-mediated mitochondrial homeostasis and activation of the mitochondria–lysosomal axis in VSMCs. In conclusion, our findings demonstrated that CD38 and its associated intracellular NAD decline are critical for Ang II-induced VSMC senescence and vascular remodeling.

Myeloid differentiation 2 deficiency attenuates AngII-induced arterial vascular oxidative stress, inflammation, and remodeling.

Vascular remodeling is a pertinent target for cardiovascular therapy. Vascular smooth muscle cell (VSMC) dysfunction plays a key role in vascular remodeling. Myeloid differentiation 2 (MD2), a cofactor of toll-like receptor 4 (TLR4), is involved in atherosclerotic progress and cardiac remodeling via activation of chronic inflammation. In this study, we explored the role of MD2 in vascular remodeling using an Ang II-induced mouse model and cultured human aortic VSMCs. MD2 deficiency suppressed Ang II-induced vascular fibrosis and phenotypic switching of VSMCs without affecting blood pressure in mice. Mechanistically, MD2 deficiency prevented Ang II-induced expression of inflammatory cytokines and oxidative stress in mice and cultured VSMCs. Furthermore, MD2 deficiency reversed Ang II-activated MAPK signaling and Ang II-downregulated SIRT1 expression. Taken together, MD2 plays a significant role in Ang II-induced vascular oxidative stress, inflammation, and remodeling, indicating that MD2 is a potential therapeutic target for the treatment of vascular remodeling-related cardiovascular diseases.