scholarly journals Inducible Prmt1 ablation in adult vascular smooth muscle leads to contractile dysfunction and aortic dissection

2021 ◽  
Author(s):  
Jung-Hoon Pyun ◽  
Byeong-Yun Ahn ◽  
Tuan Anh Vuong ◽  
Su Woo Kim ◽  
Yunju Jo ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Aortic Dissection ◽  
Vascular Smooth Muscle ◽  
Vascular Function ◽  
Ex Vivo ◽  
Elastic Fiber ◽  
Aortic Aneurysms ◽  
Aortic Dilation ◽  
Smooth Muscle Contractility

AbstractVascular smooth muscle cells (VSMCs) have remarkable plasticity in response to diverse environmental cues. Although these cells are versatile, chronic stress can trigger VSMC dysfunction, which ultimately leads to vascular diseases such as aortic aneurysm and atherosclerosis. Protein arginine methyltransferase 1 (Prmt1) is a major enzyme catalyzing asymmetric arginine dimethylation of proteins that are sources of asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase. Although a potential role of Prmt1 in vascular pathogenesis has been proposed, its role in vascular function has yet to be clarified. Here, we investigated the role and underlying mechanism of Prmt1 in vascular smooth muscle contractility and function. The expression of PRMT1 and contractile-related genes was significantly decreased in the aortas of elderly humans and patients with aortic aneurysms. Mice with VSMC-specific Prmt1 ablation (smKO) exhibited partial lethality, low blood pressure and aortic dilation. The Prmt1-ablated aortas showed aortic dissection with elastic fiber degeneration and cell death. Ex vivo and in vitro analyses indicated that Prmt1 ablation significantly decreased the contractility of the aorta and traction forces of VSMCs. Prmt1 ablation downregulated the expression of contractile genes such as myocardin while upregulating the expression of synthetic genes, thus causing the contractile to synthetic phenotypic switch of VSMCs. In addition, mechanistic studies demonstrated that Prmt1 directly regulates myocardin gene activation by modulating epigenetic histone modifications in the myocardin promoter region. Thus, our study demonstrates that VSMC Prmt1 is essential for vascular homeostasis and that its ablation causes aortic dilation/dissection through impaired myocardin expression.

scholarly journals Molecular interactions of serotonin (5-HT) and endothelin-1 in vascular smooth muscle cells: in vitro and ex vivo analyses

2014 ◽  
Vol 306 (2) ◽  
pp. C143-C151 ◽  
Author(s):  
Subha Bhaskaran ◽  
Jeremy Zaluski ◽  
Amy Banes-Berceli
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Vascular Function ◽  
Vascular Reactivity ◽  
Ex Vivo ◽  
Janus Kinase ◽  
Mitogen Activated Protein Kinase ◽  
Contractile Responses ◽  
Endothelin 1

Elevated levels of serotonin (5-HT) and endothelin-1 (ET-1) may be involved in cardiovascular complications of diabetes mellitus. Data suggest supraphysiological concentrations of 5-HT (10−6 M) potentiate the ability of ET-1 to stimulate DNA synthesis and vascular smooth muscle cell (VSMC) proliferation in vitro via activation of mitogen-activated protein kinase (p42/44 MAPK) and Janus kinase 2 (JAK2) pathways. Additionally, 5-HT enhances agonist-induced contractions via p42/44 MAPK and an unknown tyrosine kinase. However, the exact mechanisms of the 5-HT/ET-1 interactions and whether these effects occur at physiological levels (10−9 M) are unknown. Therefore, we hypothesized that interactions between 5-HT and ET-1 at physiological concentrations in VSMC enhanced activation of both p42/44 MAPK and JAK2 pathways contributing to vascular growth and contractile responses. With the use of rat VSMC and Western blot analysis, our data suggest no effect of acute (30 min) preincubation with 5-HT (10−9 M) and/or ET-1 (10−9 M) on the activation of either pathway in normal or high glucose conditions. To determine if there was altered vascular reactivity in intact vessels we tested the effects of 5-HT and ET-1 interaction using myographs to measure isometric contractions of rat thoracic aortic rings. 5-HT (10−9 M) and ET-1 (10−12 M) stimulate enhanced contractile responses to each other that were inhibited by JAK2 and p42/44 MAPK antagonists. Our findings demonstrate that both 5-HT and ET-1 at physiological concentrations could interact with each other and activate p42/44 MAPK and JAK2 signaling pathways to cause an increase in smooth muscle contraction that could lead to altered vascular function.

MO583IN VITRO AND EX VIVO EXPERIMENTS OF VASCULAR CALCIFICATION

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Jana Holmar ◽  
Heidi Noels ◽  
Joachim Jankowski ◽  
Setareh Orth-Alampour
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Calcification ◽  
Vascular Smooth Muscle Cells ◽  
Incubation Time ◽  
Fetal Calf Serum ◽  
Ex Vivo ◽  
Calf Serum

Abstract Background and Aims Vascular calcification (VC) is one major complication in patients with chronic kidney disease whereas a misbalance in calcium and phosphate metabolism plays a crucial role. The mechanisms underlying VC have not been entirely revealed to date. Therefore are the studies aiming at the identification and characterization of the mediators/uremic toxins involved in VC ongoing and highly relevant. However, currently many different protocols being used in the studies of vascular calcification processes. This complicates the comparison of study outcomes, composing systematic reviews, and meta-analyses. Moreover, the reproducibility of data is hampered, and the efficiency in calcification research through the lack of a standardized protocol is reduced. In this study, we developed a standardized operating protocol for in vitro and ex vivo approaches to aiming at the comparability of these studies. Method We analysed in vitro and ex vivo experimental conditions to study VC. Vascular smooth muscle cells (HAoSMCs) were used for in vitro experiments and aortas from Wistar rats were used for ex vivo experiments. The influence of the following conditions was studied in detail: • Phosphate and calcium concentrations in calcifying media. • Incubation time. • Fetal calf serum (FCS) concentration. The degree of calcification was estimated by quantification of calcium concentrations that were normalized to protein content (in vitro) or to the dry weight of the aortic ring (ex vivo). Additionally, the aortic rings were stained using the von Kossa method. Optimal conditions for investigating medial vascular calcification were detected and summarized in the step-by-step protocol. Results We were able to demonstrate that the degree and the location of VC in vascular smooth muscle cells and aortic rings were highly dependent on the phosphate and CaCl2 concentration in the medium as well as the incubation time. Furthermore, the VC was reduced upon increasing fetal calf serum concentration in the medium. An optimized protocol for studying vascular calcification in vitro and ex vivo was developed and validated. The final protocol (Figure 1) presented will help to standardize in vitro and ex vivo approaches to investigate the processes of vascular calcification. Conclusion In the current study, we developed and validated a standardized operating protocol for systematic in vitro and ex vivo analyses of medial calcification, which is essential for the comparability of the results of future studies.

scholarly journals Stressor-Induced “Inflammaging” of Vascular Smooth Muscle Cells via Nlrp3-Mediated Pro-inflammatory Auto-Loop

2021 ◽  
Vol 8 ◽  
Author(s):  
Jaqueline Herrmann ◽  
Mengdi Xia ◽  
Manasa Reddy Gummi ◽  
Anna Greco ◽  
Annika Schacke ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Cardiovascular Mortality ◽  
Ex Vivo ◽  
Muscle Cells ◽  
Sterile Inflammation ◽  
Subsequent Reduction

Calcification of the vessel wall as one structural pathology of aged vessels is associated with high cardiovascular mortality of elderly patients. Aging is linked to chronic sterile inflammation and high burden of reactive oxygen species (ROS), leading to activation of pattern recognition receptors (PRRs) such as Nlrp3 in vascular cells. The current study investigates the role of PRR activation in the calcification of vascular smooth muscle cells (VSMCs). Therefore, in vitro cell culture of primary rat VSMCs and ex vivo aortic stimulations were used to analyze osteogenic, senescence and inflammatory markers via real-time PCR, in situ RNA hybridization, Western Blot, photometric assays and histological staining. Induction of ROS and DNA-damage by doxorubicin induces a shift of VSMC phenotype toward the expression of osteogenic, senescence and inflammatory proteins. Induction of calcification is dependent on Nlrp3 activity. Il-1β as a downstream target of Nlrp3 induces the synthetic, pro-calcifying VSMC phenotype. Inhibition of PRR with subsequent reduction of chronic inflammation might be an interesting target for reduction of calcification of VSMCs, with subsequent reduction of cardiovascular mortality of patients suffering from vessel stiffness.

scholarly journals Bcl11b is a Newly Identified Regulator of Vascular Smooth Muscle Phenotype and Arterial Stiffness

2017 ◽  
Author(s):  
Jeff Arni C. Valisno ◽  
Pavania Elavalakanar ◽  
Christopher Nicholson ◽  
Kuldeep Singh ◽  
Dorina Avram ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Arterial Stiffness ◽  
Vascular Smooth Muscle ◽  
Actin Polymerization ◽  
Genome Wide Association Study ◽  
Ex Vivo ◽  
Aortic Aneurysms ◽  
Cell Phenotype ◽  
Gene Desert ◽  
A Genome

ABSTRACTB-cell leukemia 11b (Bcl11b) is a zinc-finger transcription factor known as master regulator of T lymphocytes and neuronal development during embryogenesis. Bcl11b-interacting protein COUP-TFII is required for atrial development and vasculogenesis, however a role of Bcl11b in the adult cardiovascular system is unknown. A genome-wide association study (GWAS) recently showed that a gene desert region downstream ofBCL11Band known to function asBCL11Benhancer harbors single nucleotide polymorphisms (SNPs) associated with increased arterial stiffness. Based on these human findings, we sought to examine relations between Bcl11b and arterial function using mice with Bcl11b deletion. We report for the first time that Bcl11b is expressed in vascular smooth muscle (VSM) and transcriptionally regulates the expression of VSM contractile proteins smooth muscle myosin and smooth muscle α-actin. Lack of Bcl11b in VSM-specific Bcl11b null mice (BSMKO) resulted in increased expression of Ca++-calmodulin-dependent serine/threonine phosphatase calcineurin in BSMKO VSM cells, cultured in serum-free condition, and in BSMKO aortas, which showed an inverse correlation with levels of phosphorylated VASPS239, a regulator of cytoskeletal actin rearrangements. Moreover, decreased pVASPS239in BSMKO aortas was associated with increased actin polymerization (F/G actin ratio). Functionally, aortic force, stress and wall tension, measured ex vivo in organ baths, were increased in BSMKO aortas and BSMKO mice had increased pulse wave velocity, thein vivoindex of arterial stiffness, compared to WT littermates. Despite having no effect on baseline blood pressure or angiotensin II-induced hypertension, Bcl11b deletion in VSM increased the incidence of aortic aneurysms in BSMKO mice. Aneurysmal aortas from angII-treated BSMKO mice had increased number of apoptotic VSM cells. In conclusion, we identified VSM Bcl11b as a novel and crucial regulator of VSM cell phenotype and vascular structural and functional integrity.

scholarly journals Dependence of proliferative vascular smooth muscle cells on CD98hc (4F2hc, SLC3A2)

2009 ◽  
Vol 206 (11) ◽  
pp. 2397-2406 ◽  
Author(s):  
Per Fogelstrand ◽  
Chloé C. Féral ◽  
Ramin Zargham ◽  
Mark H. Ginsberg
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Intimal Hyperplasia ◽  
Ex Vivo ◽  
Muscle Cells ◽  
Amino Acid Transporters ◽  
Vessel Morphology

Activation of vascular smooth muscle cells (VSMCs) to migrate and proliferate is essential for the formation of intimal hyperplasia. Hence, selectively targeting activated VSMCs is a potential strategy against vaso-occlusive disorders such as in-stent restenosis, vein-graft stenosis, and transplant vasculopathy. We show that CD98 heavy chain (CD98hc) is markedly up-regulated in neointimal and cultured VSMCs, and that activated but not quiescent VSMCs require CD98hc for survival. CD98hc mediates integrin signaling and localizes amino acid transporters to the plasma membrane. SMC-specific deletion of CD98hc did not affect normal vessel morphology, indicating that CD98hc was not required for the maintenance of resident quiescent VSMCs; however, CD98hc deletion reduced intimal hyperplasia after arterial injury. Ex vivo and in vitro, loss of CD98hc suppressed proliferation and induced apoptosis in VSMCs. Furthermore, reconstitution with CD98hc mutants showed that CD98hc interaction with integrins was necessary for the survival of VSMCs. These studies establish the importance of CD98hc in VSMC proliferation and survival. Furthermore, loss of CD98hc was selectively deleterious to activated VSMCs while sparing resident quiescent VSMCs, suggesting that activated VSMCs are physiologically dependent on CD98hc, and hence, CD98hc is a potential therapeutic target in vaso-occlusive disorders.

scholarly journals microRNA overexpression in slow transit constipation leads to reduced NaV1.5 current and altered smooth muscle contractility

Gut ◽  
2019 ◽  
Vol 69 (5) ◽  
pp. 868-876
Author(s):  
Amelia Mazzone ◽  
Peter R Strege ◽  
Simon J Gibbons ◽  
Constanza Alcaino ◽  
Vikram Joshi ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Current Density ◽  
Ex Vivo ◽  
Slow Transit Constipation ◽  
Organotypic Cultures ◽  
Smooth Muscle Contractility ◽  
Slow Transit ◽  
Transit Constipation ◽  
Muscularis Externa

ObjectiveThis study was designed to evaluate the roles of microRNAs (miRNAs) in slow transit constipation (STC).DesignAll human tissue samples were from the muscularis externa of the colon. Expression of 372 miRNAs was examined in a discovery cohort of four patients with STC versus three age/sex-matched controls by a quantitative PCR array. Upregulated miRNAs were examined by quantitative reverse transcription qPCR (RT-qPCR) in a validation cohort of seven patients with STC and age/sex-matched controls. The effect of a highly differentially expressed miRNA on a custom human smooth muscle cell line was examined in vitro by RT-qPCR, electrophysiology, traction force microscopy, and ex vivo by lentiviral transduction in rat muscularis externa organotypic cultures.ResultsThe expression of 13 miRNAs was increased in STC samples. Of those miRNAs, four were predicted to target SCN5A, the gene that encodes the Na+ channel NaV1.5. The expression of SCN5A mRNA was decreased in STC samples. Let-7f significantly decreased Na+ current density in vitro in human smooth muscle cells. In rat muscularis externa organotypic cultures, overexpression of let-7f resulted in reduced frequency and amplitude of contraction.ConclusionsA small group of miRNAs is upregulated in STC, and many of these miRNAs target the SCN5A-encoded Na+ channel NaV1.5. Within this set, a novel NaV1.5 regulator, let-7f, resulted in decreased NaV1.5 expression, current density and reduced motility of GI smooth muscle. These results suggest NaV1.5 and miRNAs as novel diagnostic and potential therapeutic targets in STC.

scholarly journals Dysfunctional vascular smooth muscle cells mediate early and late-stage neuroinflammation and Tau hyperphosphorylation

2021 ◽  
Author(s):  
Jorge A. Aguilar-Pineda ◽  
Karin J. Vera-Lopez ◽  
Pallavi Shrivastava ◽  
Rita Nieto-Montesinos ◽  
Miguel A. Chávez-Fumagalli ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Ex Vivo ◽  
Muscle Cells ◽  
Dependent Manner ◽  
Tau Hyperphosphorylation

SUMMARYDespite the emerging evidence implying early vascular contributions to neurogenerative syndromes, the role of vascular smooth muscle cells (VSMCs) in the pathogenesis of Alzheimer’s disease is still not well understood. Herein, we show that VSMCs in brains of AD patients and the animal model of the disease, are deficient in multiple VSMC-contractile markers which correlated with Tau accumulation in brain arterioles. Ex vivo and in vitro experiments demonstrated that VSMCs undergo dramatic phenotypic transitions under AD-like conditions, adopting pro-inflammatory and synthetic phenotypes. Notably, these changes coincided with Tau hyperphosphorylation at residues Y18, T205 and S262. We also observed that loss of VSMC markers occurred in an age-dependent manner, and that expression of Sm22α and α-Sma proteins were inversely correlated with CD68 and Tau accumulation in brain arterioles of 3xTg-AD mice. Together, these findings further support the contribution of VSMCs in AD pathogenesis, and nominate VSMCs as potential novel therapeutic target in AD.Graphical Abstract

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