Smooth Muscle Cell Hypertrophy Research Articles

High salt-induced hypertrophy of human vascular smooth muscle cells associated with a decrease in glycocalyx

All health organizations agree that, presently, the average daily salt (sodium chloride) consumption per person has attained almost double the recommended amount. A chronic high salt diet contributes to the increase in blood pressure and to the development of cardiovascular disease. Although our knowledge of hypertension, in general, is abundant, little is known about salt-sensitive hypertension.Here we tested the hypothesis that acute and/or chronic high salt mimicking that present in high-salt sensitive hypertensive patients may induce hypertrophy of human vascular smooth muscle cells (hVSMCs) and their nuclei that are associated with damage to the plasma membrane glycocalyx.Using quantitative 3D confocal microscopy coupled to immunofluorescence techniques, we tested the effects of acute (2–4 days) and chronic (6–16 days) treatments of hVSMCs without (145 mM) or with high (149 mM) extracellular sodium chloride. Our results showed that acute treatment with high salt significantly decreased the relative density of membrane glycocalyx without affecting the whole cell and nuclear volumes of hVSMCs. However, chronic treatments with high salts induced significant decreases in the relative density of glycocalyx accompanied by significant increases in the whole cell and nuclear volumes as well as in the protein/DNA ratio. The high salt-induced hVSMC hypertrophy was associated with a sustained increase in intracellular sodium and calcium.Our results clearly showed that, increasing salt concentration by as little as 4 mM immediately induced damage to the cell membrane glycocalyx leading to chronic Na+ and Ca2+ overloads and hVSMC hypertrophy. The latter may reduce the lumen of arteries leading to an increase in blood pressure. Future identification of the mechanisms that are implicated in a high salt-induced remodeling of hVSMCs may permit the development of new therapeutic interventions for the treatment of high salt-sensitive hypertension and the prevention of the associated cardiovascular diseases.

Abstract 021: Interleukin-21 Plays a Critical Role in Hypertension and Vascular Dysfunction

T cell derived cytokines, interleukin 17A (IL17A) and interferon gamma (IFNg), promote angiotensin II (Ang II)-induced hypertension and end-organ damage. Interleukin 21 (IL21), produced primarily by T follicular helper (Tfh) cells, has been shown to induce IL17A and IFNγ production from T effector cells. IL21 is also a potent activator of germinal center (GC) B cells and immunoglobulin (Ig) class switching. We hypothesized that IL21 plays a fundamental role in hypertension and hypertensive end-organ damage through its effects on pro-inflammatory T cell polarization, vascular dysfunction, and enhanced Ig secretion. CD4+ T cells from Ang II infused WT mice exhibit 1.5-fold increased IL21 mRNA expression and 2-fold increased IL-21 production compared to vehicle. We found IL21 -/- mice exhibit a 30mmHg reduction in systolic blood pressure (SBP) in response to 4 weeks of Ang II infusion compared to age-matched wild type (WT) mice. Further, IFNg and IL17A production from CD8+ or CD4+ T cells, respectively, was abrogated in IL21 -/- mice vs. WT mice infused with Ang II. We also found Tfh cells and GC B cells significantly increased in the aortas and mesenteric vessels of Ang II WT mice but not IL21 -/- mice. Ang II induced an increase in percent of lymph node GC B cells and IgG/IgM ratio, consistent with Ig class switching. Ang II-induced increase in renal injury was also blunted in IL21 -/- mice vs. WT mice. Mesenteric vessels from IL21 -/- mice were protected from Ang II-induced endothelial dysfunction. IL21 -/- mice also developed blunted aortic fibrosis and reduced smooth muscle cell hypertrophy after 4 weeks of Ang II vs. WT mice. IL-21 neutralization beginning 2 weeks after Ang II resulted in a 15 mmHg reduction in SBP and reversal of aortic inflammation and vascular endothelial dysfunction compared to isotype control treated animals. Lastly, CD4+ T cell production of IL21 positively correlated with SBP in human volunteers, and in fact, IL-21 production was significantly higher in hypertensive compared to normotensive subjects. Taken together, these studies provide compelling evidence that IL21 may function as a master cytokine in the pathogenesis of hypertension and suggest that therapies targeting IL21 may reduce hypertension and the associated end-organ damage.

ULTRASTRUCTURAL CHANGES IN THE WALL OF THE GREAT SAPHENOUS VEIN AT THE VARICOSE DISEASE OF VEINS OF LOWER LIMBS DEPENDING ON AGE AND ILLNESS DURATION

The aim of the study was features of ultrastructural changes in cellular elements and connective tissue carcass of the great saphenous vein (GSV) at varicose disease in depending on the duration of the disease in persons of different ages. An examination by light microscopy of 133 fragments of BPV, excised during phlebectomy in 19 patients, and an electron microscopic examination of 532 preparations were performed. Depending on the age of the patients, four age groups was distinguished: 18-44 years old (young people); 45-59 years (middle-aged people); 60-74 years old (the elderly), 75-90 years old (persons of senile age). In the wall of the GSV of young people with a small duration of the disease, there were poorly expressed pathomorphological changes characterized by moderately expressed endothelial dysfunction and minor hypertrophy of smooth muscle cells (SMC) of the middle shell. In the group of middle-aged people, in addition to age-related changes in the structure of the wall of varicose dilated GSV, pathological changes are noted that are characteristic of the long course of the disease with the development of endothelial dysfunction. The phenotypic heterogeneity of the SMC in the middle shell intensifies, and the communication links between them is altered. Disorganization of connective tissue leads to a decrease in the strength of the connective tissue vein skeleton. Hypertrophy of SMC, as a universal compensatory-adaptive response of cells, develops in response to an increase in functional load with hemodynamic disturbances in the veins of the lower limbs and to compensate for the quantitative deficiency of SMC as a result of their death. In elderly and senile age the duration of varicose disease is more than 10 years, on average - up to 25-30 years. The number of destructively altered SMC is increasing, degenerative processes and sclerotic changes are progressing. The ultrastructural analysis of biopsies showed that at the initial stage of development of varicose disease in young people with a small duration of varicose disease, morphological changes in the structure of the GSV wall are poorly expressed. With the increase in the age of the patient and the duration of the disease, changes in GSV are progressed. Involute degenerative-dystrophic changes are most pronounced in patients over 60 years of age and are an aggravating factor during varicose transformation of the GSV wall. In elderly and senile age, the compensatory possibilities of the cells decrease, the sclerotic degenerative changes in the wall of the GSV are progressed.

IGF-1 Deficiency Promotes Pathological Remodeling of Cerebral Arteries: A Potential Mechanism Contributing to the Pathogenesis of Intracerebral Hemorrhages in Aging.

Clinical and experimental studies show that age-related decline in circulating insulin-like growth factor-1 (IGF-1) levels promotes the pathogenesis of intracerebral hemorrhages, which critically contribute to the development of vascular cognitive impairment and disability in older adults. Yet, the mechanisms by which IGF-1 deficiency compromises structural integrity of the cerebral vasculature are not completely understood. To determine the role of IGF-1 deficiency in pathological remodeling of middle cerebral arteries (MCAs), we compared alterations in vascular mechanics, morphology, and remodeling-related gene expression profile in mice with liver-specific knockdown of IGF-1 (Igf1f/f + TBG-Cre-AAV8) and control mice with or without hypertension induced by angiotensin-II treatment. We found that IGF-1 deficiency resulted in thinning of the media and decreased wall-to-lumen ratio in MCAs. MCAs of control mice exhibited structural adaptation to hypertension, manifested as a significant increase in wall thickness, vascular smooth muscle cell (VSMC) hypertrophy, decreased internal diameter and up-regulation of extracellular matrix (ECM)-related genes. IGF-1 deficiency impaired hypertension-induced adaptive media hypertrophy and dysregulated ECM remodeling, decreasing elastin content and attenuating adaptive changes in ECM-related gene expression. Thus, circulating IGF-1 plays a critical role in maintenance of the structural integrity of cerebral arteries. Alterations of VSMC phenotype and pathological remodeling of the arterial wall associated with age-related IGF-1 deficiency have important translational relevance for the pathogenesis of intracerebral hemorrhages and vascular cognitive impairment in elderly hypertensive patients.

MiR-1 is increased in pulmonary hypertension and downregulates Kv1.5 channels in rat pulmonary arteries.

The expression of miR-1 is increased in lungs from the Hyp/Su5416 PAH rat model. Pulmonary artery smooth muscle cells from this animal model are more depolarized and show decreased expression and activity of voltage-dependent potassium channel (Kv)1.5. miR-1 directly targets Kv1.5 channels, reduces Kv1.5 activity and induces membrane depolarization. Antagomir-1 prevents Kv1.5 channel downregulation and the depolarization induced by hypoxia/Su5416 exposition. Impairment of the voltage-dependent potassium channel (Kv) plays a central role in the development of cardiovascular diseases, including pulmonary arterial hypertension (PAH). MicroRNAs are non-coding RNAs that regulate gene expression by binding to the 3'-untranslated region region of specific mRNAs. The present study aimed to analyse the effects of miR-1 on Kv channel function in pulmonary arteries (PA). Kv channel activity was studied in PA from healthy animals transfected with miR-1 or scrambled-miR. Kv currents were studied using the whole-cell configuration of the patch clamp technique. The characterization of the Kv1.5 currents was performed with the selective inhibitor DPO-1. miR-1 expression was increased and Kv1.5 channels were decreased in lungs from a rat model of PAH induced by hypoxia and Su5416. miR-1 transfection increased cell capacitance, reduced Kv1.5 currents and induced membrane depolarization in isolated pulmonary artery smooth muscle cells. A luciferase reporter assay indicated that KCNA5, which encodes Kv1.5 channels, is a direct target gene of miR-1. Incubation of PA with Su5416 and hypoxia (3% O2 ) increased miR-1 and induced a decline in Kv1.5 currents, which was prevented by antagomiR-1. In conclusion, these data indicate that miR-1 induces pulmonary artery smooth muscle cell hypertrophy and reduces the activity and expression of Kv channels, suggesting a pathophysiological role in PAH.

Genistein rescues hypoxia-induced pulmonary arterial hypertension through estrogen receptor and β-adrenoceptor signaling

Pulmonary vascular remodeling is an important pathological feature of pulmonary arterial hypertension (PAH), which is characterized by thickening of the medial smooth muscle layer. Hypertrophy of pulmonary artery smooth muscle cells (PASMCs) participates in the development of medial thickening. Genistein can attenuate PAH and inhibit medial thickening of pulmonary arteries. Since hypoxia is one of the main causes of pulmonary hypertension, this study aims to investigate the mechanism of genistein in inhibiting hypertrophic responses in PASMCs induced by hypoxia. Cells isolated from the chick embryo were cultured with or without genistein and subjected to hypoxia or not. The increase of cell surface area and α-smooth muscle actin (α-SMA) of PASMCs was significantly suppressed by genistein during hypoxia. This result was confirmed by the incorporation of puromycin into peptide chains and flow cytometry analysis. Constrained mRNA and protein hypoxia-inducible factor (HIF)-1α expression was improved by genistein under hypoxia condition. Genistein restored redox homeostasis by fluorescent probe determination. The effect of genistein on hypertrophic response was blocked by estrogen receptor inhibitor, β1-adrenoceptor agonist and β2-adrenoceptor antagonist. In conclusion, genistein potently attenuates hypoxia-induced hypertrophy of PASMCs, which may enable a novel therapy for PAH.

IGF‐1 deficiency promotes pathological remodeling of cerebral arteries: a potential mechanism contributing to the pathogenesis of intracerebral hemorrhages in aging

Clinical and experimental studies show that age‐related decline in circulating IGF‐1 levels promotes the pathogenesis of intracerebral hemorrhages, which critically contribute to the development of vascular cognitive impairment and disability in older adults. Yet, the mechanisms by which IGF‐1 deficiency compromises structural integrity of the cerebral vasculature are not completely understood. To determine the role of IGF‐1 deficiency in pathological remodeling of middle cerebral arteries (MCAs), we compared alterations in vascular mechanics, morphology and remodeling‐related gene expression profile in mice with liver‐specific knockdown of IGF‐1 (Igf1f/f + TBG‐Cre‐AAV8) and control mice with or without hypertension induced by angiotensin‐II treatment. We found that IGF‐1 deficiency resulted in thinning of the media and decreased wall‐to‐lumen ratio in MCAs. MCAs of control mice exhibited structural adaptation to hypertension, manifested as a significant increase in wall thickness, vascular smooth muscle cell hypertrophy, decreased internal diameter and up‐regulation of extracellular matrix (ECM)‐related genes. IGF‐1 deficiency impaired hypertension‐induced adaptive media hypertrophy and dysregulated extracellular matrix remodeling, decreasing elastin content and attenuating adaptive changes in ECM‐related gene expression. Thus, circulating IGF‐1 plays a critical role in maintenance of the structural integrity of cerebral arteries. Alterations of VSMC phenotype and pathological remodeling of the arterial wall associated with age‐related IGF‐1 deficiency have important translational relevance for the pathogenesis of ICHs and vascular cognitive impairment in elderly hypertensive patients.Support or Funding InformationThis work was supported by grants from the American Heart Association, the National Center for Complementary and Alternative Medicine, and the National Institute on AgingThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Plasma miR-199a-5p is increased in neutrophilic phenotype asthma patients and negatively correlated with pulmonary function.

ObjectiveWe investigated the relationship between plasma miRNAs levels and inflammatory characteristics in asthmatic patients.MethodsEligible adults with untreated asthma (n = 35) underwent a clinical assessment, sputum induction, and assessment of pulmonary function test and Asthma Control Test (ACT) scores. Asthma phenotypes were defined using the sputum cell count. miR-199a-5p expression was measured using quantitative real-time polymerase chain reaction (qPCR). Lipopolysaccharide (LPS) stimulation was used to detect miR-199a-5p secretion from peripheral blood-derived neutrophil, lymphocyte, macrophage and BEAS-2B cells. The correlation of miR-199a-5p expression with clinical parameters was analyzed using multiple linear regression analysis. In silico analysis predicted the target genes and signaling pathway of miR-199a-5p. Transfection of miR-199a-5p mimics in human airway smooth muscle cells (HASMCs) was performed in vitro.ResultsThe miRNA-199a-5p levels in plasma and sputum increased significantly in patients with neutrophilic asthma compared to healthy subjects (ps = 0.014 and 0.006, respectively). Expression of miR-199a-5p in the plasma of asthmatic patients positively correlated with sputum miR-199a-5p expression (r = 0.511, p = 0.021). The miR-199a-5p level was only elevated with LPS stimulation in neutrophils but not macrophages, lymphocytes, or epithelial cells from healthy controls (p < 0.01). miR-199a-5p expression increased in response to LPS (p = 0.005) and LPS combined with IL-4 (p = 0.003), but not IL-4 alone. However, peripheral neutrophils from eosinophilic asthma patients did not respond to LPS with increased miR-199a-5p expression (n = 5, p > 0.05) in contrast to the significant response from neutrophilic patients (n = 4, p < 0.0001). miR-199a-5p negatively correlated with FEV1, FVC and PEF (r = -0.377, p = 0.026; r = -0.419, p = 0.012; and r = -0.392, p = 0.024, respectively). Multivariate correlation analysis confirmed that the plasma miR-199a-5p levels negatively correlated with FEV1 in patients with asthma (Adjusted R2 = 0.164, p = 0.015). In silico analysis suggested that the WNT signaling pathway participates in miR-199a-5p mediation of smooth muscle cell hypertrophy. In vitro experiment, miR-199a-5p mimics inhibited the protein expressions of WNT2 and WNT4, decreased the c-myc expression and dramatically increased the Sm-MHC expression in HASMCs.ConclusionPlasma miR-199a-5p was increased in neutrophilic asthma and negatively correlated with pulmonary function, which suggests that miR-199a-5p actively contributes to disease pathogenesis by modulating the inflammatory process and transferring the signal from inflammatory cells to structure cells.

Loss of SMAD3 Promotes Vascular Remodeling in Pulmonary Arterial Hypertension via MRTF Disinhibition.

Vascular remodeling in pulmonary arterial hypertension (PAH) results from smooth muscle cell hypertrophy and proliferation of vascular cells. Loss of BMPR-II (bone morphogenetic protein receptor 2) signaling and increased signaling via TGF-β (transforming growth factor β) and its downstream mediators SMAD (small body size [a C. elegans protein] mothers against decapentaplegic [a Drosophila protein family])-2/3 has been proposed to drive lung vascular remodeling; yet, proteomic analyses indicate a loss of SMAD3 in PAH. We proposed that SMAD3 may be dysregulated in PAH and that loss of SMAD3 may present a pathophysiological master switch by disinhibiting its interaction partner, MRTF (myocardin-related transcription factor), which drives muscle protein expression. SMAD3 levels were measured in lungs from PAH patients, rats treated either with Sugen/hypoxia or monocrotaline (MCT), and in mice carrying a BMPR2 mutation. In vitro, effects of SMAD3 or BMPR2 silencing or SMAD3 overexpression on cell proliferation or smooth muscle hypertrophy were assessed. In vivo, the therapeutic and prophylactic potential of CCG1423, an inhibitor of MRTF, was investigated in Sugen/hypoxia rats. SMAD3 was downregulated in lungs of patients with PAH and in pulmonary arteries of three independent PAH animal models. TGF-β treatment replicated the loss of SMAD3 in human pulmonary artery smooth muscle cells (huPASMCs) and human pulmonary artery endothelial cells. SMAD3 silencing increased proliferation and migration in huPASMCs and human pulmonary artery endothelial cells. Coimmunoprecipitation revealed reduced interaction of MRTF with SMAD3 in TGF-β-treated huPASMCs and pulmonary arteries of PAH animal models. In huPASMCs, loss of SMAD3 or BMPR-II increased smooth muscle actin expression, which was attenuated by MRTF inhibition. Conversely, SMAD3 overexpression prevented TGF-β-induced activation of an MRTF reporter and reduced actin stress fibers in BMPR2-silenced huPASMCs. MRTF inhibition attenuated PAH and lung vascular remodeling in Sugen/hypoxia rats. Loss of SMAD3 presents a novel pathomechanism in PAH that promotes vascular cell proliferation and-via MRTF disinhibition-hypertrophy of huPASMCs, thereby reconciling the parallel induction of a synthetic and contractile huPASMC phenotype.

Hypertension and cardiometabolic disease.

Hypertension has a central role in cardiometabolic disease and is usually associated with metabolic disorders, such as insulin resistance, obesity, and dyslipidemia. Hyperinsulinemia may increase cardiovascular (CV) risk through its promotion of hypertension, which is possibly a result of chronic enhancement of sympathetic nervous system activity, stimulation of the renin-angiotensin-aldosterone system leading to increased renal tubular sodium reabsorption, modulating cation transport, or inducing vascular smooth muscle cell hypertrophy. The body mass index value is associated with hypertension, but additional analyses showed that the strongest link existed between visceral obesity and hypertension. In a cross-sectional study, we have already shown that pulse pressure (PP) amplification, heart rate (HR), and pulse valve velocity (PWV), but not augmentation index (Aix), are increased in patients with metabolic syndrome (MS). The basis of therapy for hypertension in MS lies in a changed way of life, involving caloric intake reduction, increased quality of food, increased physical activity, and medicamentous therapy. Such a therapy has a favorable impact not only on blood pressure (BP), but on all the components of MS, and is able to delay the onset of diabetes.

Resveratrol attenuates hyperproliferation of vascular smooth muscle cells from spontaneously hypertensive rats: Role of ROS and ROS-mediated cell signaling

Resveratrol, a natural polyphenolic compound has been reported to attenuate angiotensin II -induced vascular smooth muscle cell (VSMC) hypertrophy; however, whether resveratrol could also inhibit hyperproliferation of VSMC from spontaneously hypertensive rats (SHR) is unexplored. The present study investigates the effect of resveratrol on hyperproliferation of VSMC from SHR and the underlying molecular mechanisms responsible for this response. For these studies, aortic VSMC from SHR and Wistar-Kyoto (WKY) rats were used. The proliferation of VSMC was determined by [3H] thymidine incorporation and the levels of proteins were determined by Western blotting. The enhanced proliferation exhibited by VSMC from SHR was attenuated by resveratrol. In addition, resveratrol attenuated the overexpression of cyclin D1, cyclin E, cyclin dependent kinase 4 (Cdk4), Cdk2, phosphorylated retinoblastoma protein (pRb), Giα proteins and enhanced phosphorylation of ERK1/2 and AKT in VSMC from SHR. Furthermore, the overproduction of superoxide anion, increased NADPH oxidase activity, overexpression of Nox2, Nox4 and p47phox proteins, increased phosphorylation of EGFR, IGF-IR, and c-Src were all abrogated by resveratrol. These results suggest that resveratrol attenuates the hyperproliferation of VSMC from SHR through the inhibition of ROS, c-Src, growth factor receptor activation, MAPK/PI3K, Giα and cell cycle proteins that are implicated in VSMC hyperproliferation.

Natriuretic peptide receptor-C-mediated attenuation of vascular smooth muscle cell hypertrophy involves Gqα/PLCβ1 proteins and ROS-associated signaling.

Hypertension is associated with vascular remodeling due to hyperproliferation and hypertrophy of vascular smooth muscle cells (VSMC). Recently, we showed the implication of enhanced expression of Gqα and PLCβ1 proteins in hypertrophy of VSMCs from 16‐week‐old spontaneously hypertensive rats (SHR). The aim of this study was to investigate whether C‐ANP4‐23, a natriuretic peptide receptor‐C (NPR‐C) ligand that was shown to inhibit vasoactive peptide‐induced enhanced protein synthesis in A10 VSMC could also attenuate hypertrophy of VSMC isolated from rat model of cardiac hypertrophy and to further explore the possible involvement of Gqα/PLCβ1 proteins and ROS‐mediated signaling in this effect. The protein synthesis and cell volume, markers of hypertrophy were significantly enhanced in VSMC from 16‐week‐old SHR compared with age‐matched WKY rats and C‐ANP4‐23 treatment attenuated both to WKY levels. In addition, C‐ANP4‐23 treatment also attenuated the enhanced expression of AT1 receptor, Gqα, PLCβ1, Nox4, and p47phox proteins, the enhanced activation of EGFR, PDGFR, IGF‐1R, enhanced phosphorylation of ERK1/2/AKT and c‐Src in VSMC from SHR. Furthermore, the enhanced levels of superoxide anion and NADPH oxidase activity exhibited by VSMC from SHR were also attenuated to control levels by C‐ANP4‐23 treatment. These results indicate that C‐ANP4‐23 via the activation of NPR‐C attenuates VSMC hypertrophy through decreasing the overexpression of Gqα/PLCβ1 proteins, enhanced oxidative stress, increased activation of growth factor receptors, and enhanced phosphorylation of MAPK/AKT signaling pathways. Thus, it can be suggested that C‐ANP4‐23 may be used as a therapeutic agent for the treatment of vascular complications associated with hypertension and atherosclerosis.

Activated Hedgehog-GLI Signaling Causes Congenital Ureteropelvic Junction Obstruction.

Intrinsic ureteropelvic junction obstruction is the most common cause of congenital hydronephrosis, yet the underlying pathogenesis is undefined. Hedgehog proteins control morphogenesis by promoting GLI-dependent transcriptional activation and inhibiting the formation of the GLI3 transcriptional repressor. Hedgehog regulates differentiation and proliferation of ureteric smooth muscle progenitor cells during murine kidney-ureter development. Histopathologic findings of smooth muscle cell hypertrophy and stroma-like cells, consistently observed in obstructing tissue at the time of surgical correction, suggest that Hedgehog signaling is abnormally regulated during the genesis of congenital intrinsic ureteropelvic junction obstruction. Here, we demonstrate that constitutively active Hedgehog signaling in murine intermediate mesoderm-derived renal progenitors results in hydronephrosis and failure to develop a patent pelvic-ureteric junction. Tissue obstructing the ureteropelvic junction was marked as early as E13.5 by an ectopic population of cells expressing Ptch2, a Hedgehog signaling target. Constitutive expression of GLI3 repressor in Ptch1-deficient mice rescued ectopic Ptch2 expression and obstructive hydronephrosis. Whole transcriptome analysis of isolated Ptch2+ cells revealed coexpression of genes characteristic of stromal progenitor cells. Genetic lineage tracing indicated that stromal cells blocking the ureteropelvic junction were derived from intermediate mesoderm-derived renal progenitors and were distinct from the smooth muscle or epithelial lineages. Analysis of obstructive ureteric tissue resected from children with congenital intrinsic ureteropelvic junction obstruction revealed a molecular signature similar to that observed in Ptch1-deficient mice. Together, these results demonstrate a Hedgehog-dependent mechanism underlying mammalian intrinsic ureteropelvic junction obstruction.

Regulation of Pulmonary Vascular Smooth Muscle Contractility in Pulmonary Arterial Hypertension: Implications for Therapy.

There are two primary components that produce pulmonary arterial hypertension (PAH); aberrant structural changes (smooth muscle cell proliferation, smooth muscle cell hypertrophy, and the deposition of matrix proteins within the media of pulmonary arterial vessels), and excess vasoconstriction. However, in PAH, the target and aim of all current therapeutic agents is to reduce the contractility of the pulmonary vasculature; prostaglandins, phosphodiesterase inhibitors, guanylate cyclase stimulators, endothelin antagonists, NO inhalation and Rho kinase inhibitors all influence signaling pathways in the pulmonary vascular smooth muscle to decrease vasoconstriction, and hence, pulmonary vascular resistance (PVR). This review will therefore primarily focus on discussing the signaling pathways regulating contractility in pulmonary vascular smooth muscle, the mechanism for current treatments, as well as highlighting potential targets for the development of novel therapies.

Resveratrol prevents angiotensin II-induced hypertrophy of vascular smooth muscle cells through the transactivation of growth factor receptors

We previously showed that augmented levels of endogenous angiotensin II (AngII) contribute to vascular smooth muscle cell (VSMC) hypertrophy through the transactivation of growth factor receptors in spontaneously hypertensive rats. Resveratrol (RV), a polyphenolic component of red wine, has also been shown to attenuate AngII-evoked VSMC hypertrophy; however, the molecular mechanism mediating this response is obscure. The present study was therefore undertaken to examine whether RV could prevent AngII-induced VSMC hypertrophy through the transactivation of growth factor receptor and associated signaling pathways. AngII treatment of VSMC enhanced the protein synthesis that was attenuated towards control levels by RV pretreatment as well as by the inhibitors of NADPH oxidase, c-Src, and growth factor receptors. Furthermore, RV pretreatment also inhibited enhanced levels of superoxide anion, NADPH oxidase activity, increased expression of NADPH oxidase subunits, and phosphorylation of c-Src, EGF-R, PDGE-R, ERK1/2, and AKT1/2. In conclusion, these results indicate that RV attenuates AngII-induced VSMC hypertrophy through the inhibition of enhanced oxidative stress and activation of c-Src, growth factor receptors, and MAPK/AKT signaling. We suggest that RV could be used as a therapeutic agent in the treatment of vascular complications associated with hypertension and hypertrophy.

CLINICAL CASE OF COMBINATION THERAPY INCLUDING AMBRIZENTAN IN THE PATIENT WITH SEVERE IDIOPATHIC PULMONARY ARTERIAL HYPERTENSION

Idiopathic pulmonary hypertension (IPAH) is a rare cardiovascular disease of unknown etiology, but the most common form of pulmonary arterial hypertension, defined as mean pulmonary arterial pressure &gt;25 mmHg and pulmonary vascular resistance &gt;3 Wood Units. Endothelial dysfunction seems to play an integral role in the pathogenesis of IPAH: the activation of endothelin-1 causes the hypertrophy of smooth muscle cells and endothelial cells, fibrotic changes, immune inflammation and vasoconstriction which leads to small pulmonary arteries and arterioles remodeling. The endothelial system activation is the reason for using endothelin receptor antagonists (ERA) to block the endothelin receptors type A (ETA) or both types (ETA, ETB). ERA, as the main class of PAH-specific therapy, is presented by bosentan and macitentan, dual endothelin receptor antagonists, and ambrisentan, non-sulfonamide, ETA-selective ERA. This clinical case demonstrates the successful treatment with ambrisentan as the part of combination therapy in the patient with severe IPAH.

MP26-18 TIME-DEPENDENT BLADDER AND URETHRAL DYSFUNCTIONS IN AGING RATS

You have accessJournal of UrologyUrodynamics/Lower Urinary Tract Dysfunction/Female Pelvic Medicine: Basic Research & Pathophysiology I1 Apr 2017MP26-18 TIME-DEPENDENT BLADDER AND URETHRAL DYSFUNCTIONS IN AGING RATS Takuma Oshiro, Minoru Miyazato, Asuka Ashikari, and Seiich Saito Takuma OshiroTakuma Oshiro More articles by this author , Minoru MiyazatoMinoru Miyazato More articles by this author , Asuka AshikariAsuka Ashikari More articles by this author , and Seiich SaitoSeiich Saito More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2017.02.789AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Age-related symptoms such as urinary retention, poor urine flow, and/or incontinence have been attributed to detrusor underactivity (DU). Our recent data showed that in continuous cystometry, bladder contractility did not diminish but post-void residual urine volume was higher in aging rats than in young rats. Thus, the assumption that bladder and urethral dysfunction occur simultaneously in aging rats seems reasonable. Therefore, we investigated this possibility by measuring time-dependent changes of bladder and urethral functions in rats. METHODS Female Sprague-Dawley rats (young rats aged 3 months and rats aged 12 and 24 months) were used. 1) Continuous cystometry was performed under awake condition in each group. 2) Urethral activity was evaluated by simultaneous recordings of intravesical pressure under isovolumetric conditions and urethral perfusion pressure (UPP) under urethane anesthesia in 3-month-old and 12-month-old rats. 3) Masson's trichrome staining in the bladder was performed in each group. RESULTS 1) Cystometric evaluations revealed that the intercontraction intervals in the 24-month-old rats were prolonged (p < 0.01) when compared with those in the 3-month-old or 12-month-old rats. In the 24-month-old rats, residual urine volume was significantly higher than in the 3-month-old or 12-month-old rats, and non-voiding contractions were prominent. However, the amplitude of bladder contraction did not differ among the three groups. 2) UPP relaxation (baseline UPP minus nadir UPP) was more significantly diminished (64%) in the 12-month-old rats than in the 3-month-old rats (p < 0.05). The mean rate and amplitude of high-frequency oscillation (HFO) of urethral striated muscle were also significantly lower (12% and 41%, respectively) in the 12-month-old rats than in the 3-month-old rats. 3) In the bladders of the 24-month-old rats, increases in smooth muscle cell hypertrophy and fibrous tissue were observed. CONCLUSIONS 1) Our aging model that focused on bladder function showed increased intercontraction intervals and non-voiding bladder contractions with increased residual urine volume, suggesting detrusor hyperactivity with impaired contractility bladder activity. 2) Our aging model that focused on urethral function indicates urethral dysfunction, as evident from the reduction in HFO activity of the urethral striated muscle and the urethral relaxation. Thus, age-associated bladder and urethral dysfunction seem likely to occur simultaneously, which leads to DU with a vicious cycle. © 2017FiguresReferencesRelatedDetails Volume 197Issue 4SApril 2017Page: e326-e327 Advertisement Copyright & Permissions© 2017MetricsAuthor Information Takuma Oshiro More articles by this author Minoru Miyazato More articles by this author Asuka Ashikari More articles by this author Seiich Saito More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Identification of genes associated with the effect of inflammation on the neurotransmission of vascular smooth muscle cell

Vascular smooth muscle cell (VSMC) accumulation and hypertrophy are common in vascular disorders, and inflammation has a crucial role in the development of these diseases. To investigate the effect of inflammation on the neurotransmission of VSMC, bioinformatic analysis was performed, following next generation sequencing. Genes of lipopolysaccharide (LPS)-treated A7r5 cells and phosphate-buffered saline (PBS)-treated A7r5 cells were sequenced via next generation sequencing, and each assay was repeated three times. Differentially expressed genes (DEGs) were obtained using the NOISeq package in R. Subsequently, their potential functions were predicted by functional and pathway enrichment analyses using the Database for Annotation, Visualization and Integrated Discovery online tool. Interaction relationships of the proteins enriched in pathways associated with neurological diseases, the proteins which had interaction relationships with adrenoceptor α 1D (ADRA1D) or calcium voltage-gated channel subunit α1 S (CACNA1S), separately, were obtained from STRING, and protein-protein interaction (PPI) networks were constructed using Cytoscape software. A total of 2,038 DEGs, including 1,094 upregulated and 944 downregulated genes in the LPS treatment group were identified when compared with the control group. Enrichment analyses showed that NADH:Ubiquinone Oxidoreductase Core Subunit V2 (NDUFV2) was involved in several neurological diseases, including oxidative phosphorylation, Alzheimer's disease, Parkinson's disease and Huntington's disease. Furthermore, NDUFV2 (degree, 20) had a higher degree in the PPI network for DEGs enriched in pathways associated with neurological diseases. In the PPI network for ADRA1D, CACNA1S and the DEGs interacting with them, prohibitin (PHB), oxytocin receptor (OXTR), collapsin response mediator protein 1 (CRMP1) and dihydropyrimidinase like 2 (DPYSL2) had interaction relationships with both ADRA1D and CACNA1S. To conclude, the present study revealed that NDUFV2, PHB, OXTR, CRMP1 and DPYSL2 may have key roles in the effect of inflammation on neurotransmission of VSMC.

Blood Lipids and Leptin Levels in Patients with Ischemic Heart Disease and Concomitant Non-Alcoholic Fatty Liver Disease after Treatment with Atorvastatin

Non-alcoholic fatty liver disease which is regarded as an independent predictor of cardiovascular diseases plays a significant role in the development of ischemic heart disease. In patients with verified ischemic heart disease, hyperleptinemia causes hypertrophy of vascular smooth muscle cells, increases the synthesis of endothelial growth factor as well as the accumulation of reactive oxygen species in the vascular wall and leads to elevated expression of endothelin-1, which is also an indicator of its influence on vascular remodeling. Leptin is a predictor of a higher functional class of angina pectoris and heart rhythm disorders; it may be used as an indirect marker of systemic inflammation as well. Pathogenic basis for ischemic heart disease treatment is hypolipidemic therapy with statins as the medications of choice; in addition to basic hypolipidemic action, they improve endothelial function increasing nitric oxide synthesis possessing anti-inflammatory, anti-ischemic, antiaggregatory, antithrombotic and profibrinolytic action, as well as antioxidant and antiproliferative effects.The objective of the research was to study changes in blood lipids and leptin levels in patients with ischemic heart disease and concomitant non-alcoholic fatty liver disease after a course of atorvastatin. Materials and methods. 54 patients with ischemic heart disease and concomitant non-alcoholic fatty liver disease were examined; there were 26 individuals who did not take atorvastatin and 28 individuals taking atorvastatin at a dose of 40 mg per day for 3 months. All the patients underwent anthropometry, determination of blood lipids, leptin and liver transaminase levels, electrocardiography, echocardiography, ultrasound of the internal organs.Results. A significant decrease in the average level of total cholesterol (p&lt;0.01), concentration of low-density lipoproteins (p&lt;0.01) and leptin level (p&lt;0.01) was detected in patients after 3 months of atorvastatin use. Moreover, there was detected a direct correlation between leptin level and triglyceride concentration, leptin level and the body mass index, leptin level and waist circumference, leptin level and hip circumference, as well as a high correlation between total cholesterol and low-density lipoproteins, and total cholesterol and the body mass index.Conclusions. The administration of atorvastatin to patients with ischemic heart disease and concomitant non-alcoholic fatty liver disease at a dose of 40 mg per day improves the patients’ general condition and promotes a significant decrease in the levels of pro-atherogenic fractions of blood lipids and leptin level, as well as promotes the reduction in risk factors for comorbid pathology and prevents the occurrence of its complications.

Loss of smooth muscle cell disintegrin and metalloproteinase 17 transiently suppresses angiotensin II-induced hypertension and end-organ damage

Hypertension is associated with hypertrophy and hyperplasia of smooth muscle cells (SMCs). Disintegrin and metalloproteinase 17 (ADAM17) is a membrane-bound enzyme reported to mediate SMC hypertrophy through activation of epidermal growth factor receptor (EGFR). We investigated the role of ADAM17 in Ang II-induced hypertension and end-organ damage. VSMC was isolated from mice with intact ADAM17 expression (Adam17f/f) or lacking ADAM17 in the SMC (Adam17f/f/CreSm22). Human VSMCs were isolated from the aorta of donors, and ADAM17 deletion was achieved by siRNA transfection. Ang II suppressed proliferation and migration of Adam17-deficient SMCs, but did not affect apoptosis (mouse and human), this was associated with reduced activation of EGFR and Erk1/2 signaling. Adam17f/f/CreSm22 and littermate Adam17f/f mice received saline or Ang II (Alzet pumps, 1.5mg/kg/d; 2 or 4weeks). Daily blood pressure measurement in conscious mice (telemetry) showed suppressed hypertension in Adam17f/f/CreSm22 mice during the first week of Ang II infusion, but by the second week, it become comparable to that in Adam17f/f mice. EGFR activation remained suppressed in Adam17f/f/CreSm22-Ang II arteries. Ex vivo vascular function and compliance assessed in mesenteric arteries were comparable between genotypes. Consistent with the transient protection against Ang II-induced hypertension, Adam17f/f/CreSm22 mice exhibited significantly lower cardiac hypertrophy and fibrosis, and renal fibrosis at 2weeks post-Ang II, however this protection was abolished by the fourth week of Ang II infusion. In conclusion, while Adam17-deficiency suppresses Ang II-induced SMC remodeling in vitro, in vivo Adam17-deficiency provides only a transient protective effect against Ang II-mediated hypertension and end-organ damage.