Abstract 378: Cytochrome b5 Reductase 3 Regulates Vascular Smooth Muscle Phenotypic Switching

2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Amogha Vijayvargiya ◽  
Anh Nguyen ◽  
Megan P Miller ◽  
Scott Hahn ◽  
Adam C Straub
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Cytochrome B5 ◽  
Muscle Cells ◽  
Phenotypic Switching ◽  
Serum Starvation ◽  
Contractile State ◽  
Cytochrome B5 Reductase ◽  
Arterial Blood

Contractile vascular smooth muscle cells (VSMC) play a key role in the regulation of arterial blood vessel tone and cardiovascular health. However, in many vascular diseases, VSMCs undergo a phenotypic switch from a contractile state to a synthetic phenotype, where loss of the contractile markers myosin heavy chain 11 (Myh11), smooth muscle alpha actin (ACTA2) and transgelin (SM22) are observed and proliferation is increased. Recent evidence from our lab demonstrates that cytochrome b5 reductase 3 (Cyb5R3) regulates the redox state of soluble guanylate cyclase to control cGMP levels in VSMCs. Because cGMP modulates protein kinase G activity, a critical kinase that maintains VSMCs in a contractile state, we tested the hypothesis that Cyb5R3 is critical for maintenance of the contractile phenotype. To test this hypothesis, we transduced primary rat aortic smooth muscle cells with non-targeting (NT) or Cyb5R3 shRNA followed by serum starvation for 24, 48, and 72 hours to induce phenotypic switching. After each time point, mRNA measurements of Cyb5R3, Myh11, ACTA2, and SM22 were conducted using RT-PCR. In NT shRNA transduced VSMCs, we observed a significant increase in Cyb5R3, Myh11, ACTA2, and SM22 mRNA, but not in Cyb5R3 knockdown VSMCs. Next, we conducted proliferation studies by serum starving NT shRNA and Cyb5R3 shRNA treated VSMCs for 24 hours followed by stimulation of platelet growth factor BB (PDGF-BB, 40 ng/mL). After 24 hours of PDGF-BB treatment, Cyb5R3 deficient cells showed augmented proliferation compared to control cells measured by 3 H-thymidine incorporation. Together, our data suggest that Cyb5R3 is essential for VSMC phenotypic switching and proliferation, which may unravel a new therapeutic target for treating individuals with cardiovascular disease.

scholarly journals TRPC6 regulates phenotypic switching of vascular smooth muscle cells through plasma membrane potential‐dependent coupling with PTEN

2019 ◽  
Vol 33 (9) ◽  
pp. 9785-9796 ◽  
Author(s):  
Takuro Numaga‐Tomita ◽  
Tsukasa Shimauchi ◽  
Sayaka Oda ◽  
Tomohiro Tanaka ◽  
Kazuhiro Nishiyama ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Plasma Membrane ◽  
Membrane Potential ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Muscle Cells ◽  
Phenotypic Switching ◽  
Plasma Membrane Potential

scholarly journals RGS5 Attenuates Baseline Activity of ERK1/2 and Promotes Growth Arrest of Vascular Smooth Muscle Cells

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1748
Author(s):  
Eda Demirel ◽  
Caroline Arnold ◽  
Jaspal Garg ◽  
Marius Andreas Jäger ◽  
Carsten Sticht ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Map Kinase ◽  
Vascular Smooth Muscle Cells ◽  
Muscle Cells ◽  
Genetic Ablation ◽  
Variable Expression ◽  
Arterial Blood

The regulator of G-protein signaling 5 (RGS5) acts as an inhibitor of Gαq/11 and Gαi/o activity in vascular smooth muscle cells (VSMCs), which regulate arterial tone and blood pressure. While RGS5 has been described as a crucial determinant regulating the VSMC responses during various vascular remodeling processes, its regulatory features in resting VSMCs and its impact on their phenotype are still under debate and were subject of this study. While Rgs5 shows a variable expression in mouse arteries, neither global nor SMC-specific genetic ablation of Rgs5 affected the baseline blood pressure yet elevated the phosphorylation level of the MAP kinase ERK1/2. Comparable results were obtained with 3D cultured resting VSMCs. In contrast, overexpression of RGS5 in 2D-cultured proliferating VSMCs promoted their resting state as evidenced by microarray-based expression profiling and attenuated the activity of Akt- and MAP kinase-related signaling cascades. Moreover, RGS5 overexpression attenuated ERK1/2 phosphorylation, VSMC proliferation, and migration, which was mimicked by selectively inhibiting Gαi/o but not Gαq/11 activity. Collectively, the heterogeneous expression of Rgs5 suggests arterial blood vessel type-specific functions in mouse VSMCs. This comprises inhibition of acute agonist-induced Gαq/11/calcium release as well as the support of a resting VSMC phenotype with low ERK1/2 activity by suppressing the activity of Gαi/o.

Micro-RNA Regulation of Vascular Smooth Muscle Cells and Its Significance in Cardiovascular Diseases

2021 ◽  
Author(s):  
Duong Ngoc Diem Nguyen ◽  
William M Chilian ◽  
Shamsul Mohd Zain ◽  
Muhammad Fauzi Daud ◽  
Yuh Fen Pung
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Intracellular Signaling ◽  
Neointimal Hyperplasia ◽  
Muscle Cells ◽  
Micro Rna ◽  
Phenotypic Switching ◽  
Micro Rnas

Cardiovascular disease (CVD) is among the leading causes of death worldwide. Micro-RNAs (miRNAs), regulatory molecules that repress protein expression, have attracted considerable attention in CVD research. The vasculature plays a big role in CVD development and progression and dysregulation of vascular cells underlies the root of many vascular diseases. This review provides a brief introduction of the biogenesis of miRNAs and exosomes, followed by overview of the regulatory mechanisms of miRNAs in vascular smooth muscle cells (VSMCs) intracellular signaling during phenotypic switching, senescence, calcification and neointimal hyperplasia. Evidence of extracellular signaling of VSMCs and other cells via exosomal and circulating miRNAs was also presented. Lastly, current drawbacks and limitations of miRNA studies in CVD research and potential ways to overcome these disadvantages were discussed in detail. In-depth understanding of VSMC regulation via miRNAs will add substantial knowledge and advance research in diagnosis, disease progression and/or miRNA-derived therapeutic approaches in CVD research.

Abstract 107: Cytochrome B5 Reductase 3 Sensitizes Soluble Guanylate Cyclase to Nitric Oxide in Vascular Smooth Muscle

Hypertension ◽  
2015 ◽  
Vol 66 (suppl_1) ◽  
Author(s):  
Adam C Straub ◽  
Anh T Nguyen ◽  
Mizanur Rahaman ◽  
Stephanie M Mutchler ◽  
Megan Miller ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Blood Pressure ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Guanylate Cyclase ◽  
Soluble Guanylate Cyclase ◽  
Cytochrome B5 ◽  
Heme Iron ◽  
Cytochrome B5 Reductase ◽  
Arterial Blood

The inability nitric oxide (NO) to stimulate soluble guanylate cyclase (sGC) has been linked to numerous cardiovascular diseases (CVD) including hypertension. While several studies have defined the importance of sGC expression in the cardiovascular system, the basic mechanisms that regulate sGC activity remain incompletely understood. Here, we report for the first time that sGC heme iron redox state, which is essential for NO-induced sGC activation, is regulated by cytochrome B5 reductase 3 (CyB5R3). Genetic knockdown and pharmacological inhibition of CyB5R3 in primary rat vascular smooth muscle cells resulted in a 60% loss in cGMP production. Conversely, the sGC activator Bay 58-2667, which activates oxidized or heme free sGC, reversed these effects. Consistent with our cell culture work, purified protein studies demonstrate that CyB5R3 can directly reduce oxidized sGC heme iron and sensitize sGC to NO. To test the functional importance of Cyb5R3 activity, we cultured mouse thoracodorsal arteries with a pharmacological inhibitor of Cyb5R3 (ZINC 747) and performed vascular reactivity studies using pressure myography. Arteries treated with ZINC 747 showed decreased responsiveness the NO donor DETA-NONOate but increase sensitivity to Bay 58-2667. We then treated mice with 10mg/kg/day of ZINC 747 using osmotic mini pumps, which caused an increase in mean arterial blood pressure (107.5±3.4 vs 131±13.16) measured via radio telemetry. Lastly, translational studies reveal that the CyB5R3 T116S polymorphism with allele frequency 0.23 only in African Americans is unable to reduce sGC and correlates with increased blood pressure. Considering the defining role of sGC in NO signaling and the fact that the oxidation state of sGC may predict responses to NO therapies and new classes of sGC activator medications, we anticipate that these studies may significantly impact our understanding of biology, precision therapeutics (right drug for the right patient) and pharmacogenetics (T117S SNP based drug selection).

Abstract MP19: Smooth Muscle Cell Cytochrome B5 Reductase 3 Causes Heart Failure With Reduced Ejection Fraction Under Hypoxic Stress

Hypertension ◽  
2020 ◽  
Vol 76 (Suppl_1) ◽  
Author(s):  
Brittany G Durgin ◽  
Adam C Straub ◽  
Katherine C Wood ◽  
Scott A Hahn
Keyword(s):  
Heart Failure ◽  
Pulmonary Hypertension ◽  
Smooth Muscle ◽  
Ejection Fraction ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Cytochrome B5 ◽  
Muscle Cells ◽  
Right Heart

Pulmonary hypertension causes increased pulmonary vascular resistance and right heart failure. Nitric oxide (NO) binds to its receptor soluble guanylyl cyclase (sGC) within vascular smooth muscle cells in its reduced heme (Fe 2+ ) form to increase intracellular cGMP production, activate protein kinase G signaling, and induce vessel relaxation. In pulmonary hypertension, endothelial damage leading to decreased NO bioavailability combined with oxidation of the sGC heme (Fe 3+ ) in vascular smooth muscle cells rendering it NO-insensitive results in vasonstriction. Notably, we have previously shown that cytochrome b5 reductase 3 (CYB5R3) in vascular smooth muscle cells is an sGC reductase (Fe 3+ to Fe 2+ ) that maintains NO-dependent vasodilation in vascular disease. We therefore hypothesized that CYB5R3 confers protection in pulmonary hypertension. To test this, we subjected smooth muscle cell-specific CYB5R3 knockout mice (SMC CYB5R3 KO) to 21 days of continuous hypoxia (10% O 2 ) and assessed vascular and cardiac function. We found that SMC CYB5R3 KO led to enhanced cardiac hypertrophy when compared to wild-type (WT) controls (n=8/ group). Specifically, SMC CYB5R3 KO mice had a larger right ventricle per tibia size, left ventricle mass, and Fulton index compared to WT (n=8/ group). Moreover, SMC CYB5R3 KO mice had a significantly impaired ejection fraction and fractional shortening, and increased left ventricular posterior wall pressure (n=3-5/group). No differences in right heart function or overall cardiac fibrosis were observed between groups (n=3-5/group). With respect to vascular function, hypoxic pulmonary arteries from SMC CYB5R3 KO mice also had a blunted response to sodium nitroprusside induced NO-dependent vasodilation though no difference in sGC activator BAY 58-2667 induced NO-independent vasodilation was observed as compared to WT (n=8-11/ group). No differences in pulmonary arterial sGC levels or medial area were observed between groups (n=6-7). Combined, these data implicate that loss of SMC CYB5R3 exacerbates cardiomyocyte hypertrophy and reduces cardiac function independent of pulmonary pressure differences.

scholarly journals MicroRNA regulation of BMP signaling; cross-talk between endothelium and vascular smooth muscle cells

2018 ◽  
Author(s):  
Charlene Watterston ◽  
Lei Zeng ◽  
Abidemi Onabadejo ◽  
Sarah J Childs
Keyword(s):  
Endothelial Cells ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Vascular Function ◽  
Muscle Cells ◽  
Phenotypic Switching ◽  
Vascular Stability ◽  
Bmp Signalling

AbstractVascular smooth muscle cells (vSMC) are essential to the integrity of blood vessels, and therefore an attractive target of therapeutics aimed at improving vascular function. Smooth muscle cells are one of the few cell types that maintain plasticity and can switch phenotypes from differentiated (contractile) to de-differentiated (synthetic) and vice versa. As small regulatory transcripts, miRNAs act as genetic ‘fine tuners’ of posttranscriptional events and can act as genetic switches promoting phenotypic switching. The microRNAmiR26atargets the BMP signalling effector,smad1. We show that loss ofmiR26leads to hemorrhage (a loss of vascular stability)in vivo, suggesting altered vascular differentiation. Reduction inmiR26alevels increasessmad1mRNA and phospho-Smad1 (pSmad1) levels. We show that increasing BMP signalling by overexpression ofsmad1also leads to hemorrhage and that normalization of Smad1 levels through double knockdown ofmiR26andsmad1rescues hemorrhage suggesting a direct relationship betweenmiR26andsmad1and vascular stability. Using a BMP genetic reporter and pSmad1 staining we show that the effect ofmiR26on vascular instability is non-autonomous; BMP signalling is active in embryonic endothelial cells, but not in smooth muscle cells. Nonetheless, increased BMP signalling due to loss ofmiR26results in an increase inacta2-expressing smooth muscle cell numbers and promotes a differentiated smooth muscle morphology. Taken together our data suggests thatmiR26modulates BMP signalling in endothelial cells and indirectly promotes a differentiated smooth muscle phenotype. Our data also suggests that crosstalk from BMP-responsive endothelium to smooth muscle is important for its differentiation.

scholarly journals Akt/eNOS and MAPK Signaling Pathways Mediated the Phenotypic Switching of Thoracic Aorta Vascular Smooth Muscle Cells in Aging/Hypertensive Rats

2018 ◽  
pp. 543-553 ◽  
Author(s):  
L. ZHANG ◽  
Z. XU ◽  
Y. WU ◽  
J. LIAO ◽  
F. ZENG ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Western Blot ◽  
Smooth Muscle Cells ◽  
Thoracic Aorta ◽  
Vascular Smooth Muscle Cells ◽  
Muscle Cells ◽  
Mapk Signaling ◽  
Phenotypic Switching ◽  
Hypertensive Rats

Considerable evidence demonstrates that phenotypic switching of vascular smooth muscle cells (VSMCs) is influenced by aging and hypertension. During phenotypic switching, VSMCs undergo a switch to a proliferative and migratory phenotype, with this switch being a common pathology in cardiovascular diseases. The aim of this study was to explore the joint influence of age and hypertension on thoracic aortic smooth muscle phenotypic switching and the balance of Akt and mitogen-activated protein kinase (MAPK) signaling during this switch. Different ages of spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY) were used to establish hypertension and aging models. The phenotypic state was determined by detecting the marker proteins α-SM-actin, calponin, and osteopontin (OPN) via immunohistochemical staining and Western blot. Signaling proteins associated with the Akt and MAPK pathways were detected in rat thoracic aorta using Western blot. Both aging and hypertension caused a decrease in contractile (differentiated) phenotype markers (α-SM-actin and calponin), while the synthetic (proliferative or de-differentiated) phenotype maker was elevated (OPN). When combining hypertension and aging, this effect was enhanced, with Akt signaling decreased, while MAPK signaling was increased. These results suggested that VSMCs phenotype switching is modulated by a balance between Akt and MAPK signaling in the process of aging and hypertension.

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