HIF2A gain-of-function mutation modulates the stiffness of smooth muscle cells and compromises vascular mechanics.
Ontology highlight
ABSTRACT:
SUBMITTER: Chan XY
PROVIDER: S-EPMC7995528 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:Cullin-3 (CUL3) mutations (CUL3Δ9) were previously identified in hypertensive patients with pseudohypoaldosteronism type-II (PHAII), but the mechanism causing hypertension and whether this is driven by renal tubular or extratubular mechanisms remains unknown. We report that selective expression of CUL3Δ9 in smooth muscle acts by interfering with expression and function of endogenous CUL3, resulting in impaired turnover of the CUL3 substrate RhoA, increased RhoA activity, and augmented RhoA/Rho kinase signaling. This caused vascular dysfunction and increased arterial pressure under baseline conditions and a marked increase in arterial pressure, collagen deposition, and vascular stiffness in response to a subpressor dose of angiotensin II, which did not cause hypertension in control mice. Inhibition of total cullin activity increased the level of CUL3 substrates cyclin E and RhoA, and expression of CUL3Δ9 decreased the level of the active form of endogenous CUL3 in human aortic smooth muscle cells. These data indicate that selective expression of the Cul3Δ9 mutation in vascular smooth muscle phenocopies the hypertension observed in Cul3Δ9 human subjects and suggest that mutations in CUL3 cause human hypertension in part through a mechanism involving smooth muscle dysfunction initiated by a loss of CUL3-mediated degradation of RhoA.
| S-EPMC5111503 | biostudies-literature
Project description:Mechanical compliance is emerging as an important environmental cue that can influence certain cell behaviors, such as morphology and motility. Recent in vitro studies have shown that cells preferentially migrate from less stiff to more stiff substrates; however, much of this phenomenon, termed durotaxis, remains ill-defined. To address this problem, we studied the morphology and motility of vascular smooth muscle cells on well-defined stiffness gradients. Baselines for cell spreading, polarization, and random motility on uniform gels with moduli ranging from 5 to 80 kPa were found to increase with increasing stiffness. Subsequent analysis of the behavior of vascular smooth muscle cells on gradient substrata (0-4 kPa/100 mum, with absolute moduli of 1-80 kPa) demonstrated that the morphology on gradient gels correlated with the absolute modulus. In contrast, durotaxis (evaluated quantitatively as the tactic index for a biased persistent random walk) and cell orientation with respect to the gradient both increased with increasing magnitude of gradient, but were independent of the absolute modulus. These observations provide a foundation for establishing quantitative relationships between gradients in substrate stiffness and cell response. Moreover, these results reveal common features of phenomenological cell response to chemotactic and durotactic gradients, motivating further mechanistic studies of how cells integrate and respond to multiple complex signals.
| S-EPMC2749749 | biostudies-literature
Project description:Arterial stiffness, a major cardiovascular risk factor, develops within 2 months in mice fed a high-fat, high-sucrose (HFHS) diet, serving as a model of human metabolic syndrome, and it is associated with activation of proinflammatory and oxidant pathways in vascular smooth muscle (VSM) cells. Sirtuin-1 (SirT1) is an NAD(+)-dependent deacetylase regulated by the cellular metabolic status. Our goal was to study the effects of VSM SirT1 on arterial stiffness in the context of diet-induced metabolic syndrome. Overnight fasting acutely decreased arterial stiffness, measured in vivo by pulse wave velocity, in mice fed HFHS for 2 or 8 months, but not in mice lacking SirT1 in VSM (SMKO). Similarly, VSM-specific genetic SirT1 overexpression (SMTG) prevented pulse wave velocity increases induced by HFHS feeding, during 8 months. Administration of resveratrol or S17834, 2 polyphenolic compounds known to activate SirT1, prevented HFHS-induced arterial stiffness and were mimicked by global SirT1 overexpression (SirT1 bacterial artificial chromosome overexpressor), without evident metabolic improvements. In addition, HFHS-induced pulse wave velocity increases were reversed by 1-week treatment with a specific, small molecule SirT1 activator (SRT1720). These beneficial effects of pharmacological or genetic SirT1 activation, against HFHS-induced arterial stiffness, were associated with a decrease in nuclear factor kappa light chain enhancer of activated B cells (NFκB) activation and vascular cell adhesion molecule (VCAM-1) and p47phox protein expressions, in aorta and VSM cells. In conclusion, VSM SirT1 activation decreases arterial stiffness in the setting of obesity by stimulating anti-inflammatory and antioxidant pathways in the aorta. SirT1 activators may represent a novel therapeutic approach to prevent arterial stiffness and associated cardiovascular complications in overweight/obese individuals with metabolic syndrome.
| S-EPMC4982825 | biostudies-literature
Project description:Coronary artery disease (CAD) has been the leading cause of morbidity and mortality worldwide, and its pathogenesis is closely related with the proliferation and migration of vascular smooth muscle cell (VSMC). We previously reported a truncated GATA4 protein lacking C-terminus induced by p.S335X mutation in cardiomyocyte from ventricular septal defect (VSD) patients. However, it is still unclear whether GATA4 p.S335X mutation could influence the development of CAD. GATA4 wild-type (WT) and p.S335X mutant (MU) overexpression plasmids were constructed and transfected transiently into rat coronary artery smooth muscle cell (RCSMC) to observe the proliferative and migratory abilities by MTS and wound healing assay, respectively. PCR array was used to preliminarily detect the expression of phenotypic modulation-related genes, and QRT-PCR was then carried out to verify the screened differentially expressed genes (DEGs). The results showed that, when stimulated by fetal bovine serum (10%) for 24 h or tumor necrosis factor-α (10 or 30 ng/ml) for 10 or 24 h, deletion of GATA4 C-terminus by p.S335X mutation in GATA4 enhanced the proliferation of RCSMC, without alteration of the migration capability. Twelve DEGs, including Fas, Hbegf, Itga5, Aimp1, Cxcl1, Il15, Il2rg, Il7, Tnfsf10, Il1r1, Irak1, and Tlr3, were screened and identified as phenotypic modulation-related genes. Our data might be beneficial for further exploration regarding the mechanisms of GATA4 p.S335X mutation on the phenotypic modulation of coronary VSMC.
| S-EPMC8449727 | biostudies-literature
Project description:In striated muscle, the giant protein titin spans the entire length of a half-sarcomere and extends from the backbone of the thick filament, reversibly attaches to the thin filaments, and anchors to the dense protein network of the z-disk capping the end of the half-sarcomere. However, little is known about the relationship between the basic mechanical properties of titin and muscle contractility. Here, we build upon our previous multi-filament, spatially explicit computational model of the half-sarcomere by incorporating the nonlinear mechanics of titin filaments in the I-band. We vary parameters of the nonlinearity to understand the effects of titin stiffness on contraction dynamics and efficiency. We do so by simulating isometric contraction for a range of sarcomere lengths (SLs; 1.6-3.25 µm). Intermediate values of titin stiffness accurately reproduce the passive force-SL relation for skeletal muscle. The maximum force-SL relation is not affected by titin for SL≤2.5 µm. However, as titin stiffness increases, maximum force for the four thick filament system at SL = 3.0 µm significantly decreases from 103.2 ± 2 to 58.8 ± 1 pN. Additionally, by monitoring ATP consumption, we measure contraction efficiency as a function of titin stiffness. We find that at SL = 3.0 µm, efficiency significantly decreases from 13.9 ± 0.4 to 7.0 ± 0.3 pN/ATP when increasing titin stiffness, with little or no effect below 2.5 µm. Taken together, our results suggest that, despite an increase in the fraction of motors bound to actin along the descending limb when titin is stiffer, the force-generating capacity of the motors is reduced. These results suggest that titin stiffness has the potential to affect contractile efficiency.
| S-EPMC6104699 | biostudies-literature
Project description:KATP channels, assembled from pore-forming (Kir6.1 or Kir6.2) and regulatory (SUR1 or SUR2) subunits, link metabolism to excitability. Loss of Kir6.2 results in hypoglycemia and hyperinsulinemia, whereas loss of Kir6.1 causes Prinzmetal angina-like symptoms in mice. Conversely, overactivity of Kir6.2 induces neonatal diabetes in mice and humans, but consequences of Kir6.1 overactivity are unknown.We generated transgenic mice expressing wild-type (WT), ATP-insensitive Kir6.1 [Gly343Asp] (GD), and ATP-insensitive Kir6.1 [Gly343Asp,Gln53Arg] (GD-QR) subunits, under Cre-recombinase control. Expression was induced in smooth muscle cells by crossing with smooth muscle myosin heavy chain promoter-driven tamoxifen-inducible Cre-recombinase (SMMHC-Cre-ER) mice. Three weeks after tamoxifen induction, we assessed blood pressure in anesthetized and conscious animals, as well as contractility of mesenteric artery smooth muscle and KATP currents in isolated mesenteric artery myocytes. Both systolic and diastolic blood pressures were significantly reduced in GD and GD-QR mice but normal in mice expressing the WT transgene and elevated in Kir6.1 knockout mice as well as in mice expressing dominant-negative Kir6.1 [AAA] in smooth muscle. Contractile response of isolated GD-QR mesenteric arteries was blunted relative to WT controls, but nitroprusside relaxation was unaffected. Basal KATP conductance and pinacidil-activated conductance were elevated in GD but not in WT myocytes.KATP overactivity in vascular muscle can lead directly to reduced vascular contractility and lower blood pressure. We predict that gain of vascular KATP function in humans would lead to a chronic vasodilatory phenotype, as indeed has recently been demonstrated in Cantu syndrome.
| S-EPMC3828800 | biostudies-literature
Project description:RATIONALE:Increased aortic stiffness, an important feature of many vascular diseases, eg, aging, hypertension, atherosclerosis, and aortic aneurysms, is assumed because of changes in extracellular matrix (ECM). OBJECTIVE:We tested the hypothesis that the mechanisms also involve intrinsic stiffening of vascular smooth muscle cells (VSMCs). METHODS AND RESULTS:Stiffness was measured in vitro both by atomic force microscopy (AFM) and in a reconstituted tissue model, using VSMCs from aorta of young versus old male monkeys (Macaca fascicularis) (n=7/group), where aortic stiffness increases by 200% in vivo. The apparent elastic modulus was increased (P<0.05) in old (41.7+/-0.5 kPa) versus young (12.8+/-0.3 kPa) VSMCs but not after disassembly of the actin cytoskeleton with cytochalasin D. Stiffness of the VSMCs in the reconstituted tissue model was also higher (P<0.05) in old (23.3+/-3.0 kPa) than in young (13.7+/-2.4 kPa). CONCLUSIONS:These data support the novel concept, not appreciated previously, that increased vascular stiffness with aging is attributable not only to changes in ECM but also to intrinsic changes in VSMCs.
| S-EPMC2936100 | biostudies-literature
Project description:Serum response factor (SRF) controls gene transcription in vascular smooth muscle cells (VSMCs) and regulates VSMC phenotypic switch from a contractile to a synthetic state, which plays a key role in the pathogenesis of cardiovascular diseases (CVD). It is not known how post-translational SUMOylation regulates the SRF activity in CVD. Here we show that Senp1 deficiency in VSMCs increased SUMOylated SRF and the SRF-ELK complex, leading to augmented vascular remodeling and neointimal formation in mice. Mechanistically, SENP1 deficiency in VSMCs increases SRF SUMOylation at lysine 143, reducing SRF lysosomal localization concomitant with increased nuclear accumulation and switching a contractile phenotype-responsive SRF-myocardin complex to a synthetic phenotype-responsive SRF-ELK1 complex. SUMOylated SRF and phospho-ELK1 are increased in VSMCs from coronary arteries of CVD patients. Importantly, ELK inhibitor AZD6244 prevents the shift from SRF-myocardin to SRF-ELK complex, attenuating VSMC synthetic phenotypes and neointimal formation in Senp1-deficient mice. Therefore, targeting the SRF complex may have a therapeutic potential for the treatment of CVD.
| S-EPMC11319592 | biostudies-literature
Project description:OBJECTIVE:Vascular extracellular matrix stiffening is a risk factor for aortic and coronary artery disease. How matrix stiffening regulates the transcriptome profile of human aortic and coronary vascular smooth muscle cells (VSMCs) is not well understood. Furthermore, the role of long noncoding RNAs (lncRNAs) in the cellular response to stiffening has never been explored. This study characterizes the stiffness-sensitive (SS) transcriptome of human aortic and coronary VSMCs and identifies potential key lncRNA regulators of stiffness-dependent VSMC functions. APPROACH AND RESULTS:Aortic and coronary VSMCs were cultured on hydrogel substrates mimicking physiological and pathological extracellular matrix stiffness. Total RNAseq was performed to compare the SS transcriptome profiles of aortic and coronary VSMCs. We identified 3098 genes (2842 protein coding and 157 lncRNA) that were stiffness sensitive in both aortic and coronary VSMCs (false discovery rate <1%). Hierarchical clustering revealed that aortic and coronary VSMCs grouped by stiffness rather than cell origin. Conservation analyses also revealed that SS genes were more conserved than stiffness-insensitive genes. These VSMC SS genes were less tissue-type specific and expressed in more tissues than stiffness-insensitive genes. Using unbiased systems analyses, we identified MALAT1 as an SS lncRNA that regulates stiffness-dependent VSMC proliferation and migration in vitro and in vivo. CONCLUSIONS:This study provides the transcriptomic landscape of human aortic and coronary VSMCs in response to extracellular matrix stiffness and identifies novel SS human lncRNAs. Our data suggest that the SS transcriptome is evolutionarily important to VSMCs function and that SS lncRNAs can act as regulators of stiffness-dependent phenotypes.
| S-EPMC5881588 | biostudies-literature
Project description:Vascular smooth muscle cells (vSMCs) retain the ability to undergo modulation in their phenotypic continuum, ranging from a mature contractile state to a proliferative, secretory state. vSMC differentiation is modulated by a complex array of microenvironmental cues, which include the biochemical milieu of the cells and the architecture and stiffness of the extracellular matrix. In this study, we demonstrate that by using UV-assisted capillary force lithography (CFL) to engineer a polyurethane substratum of defined nanotopography and stiffness, we can facilitate the differentiation of cultured vSMCs, reduce their inflammatory signature, and potentially promote the optimal functioning of the vSMC contractile and cytoskeletal machinery. Specifically, we found that the combination of medial tissue-like stiffness (11?MPa) and anisotropic nanotopography (ridge width_groove width_ridge height of 800_800_600?nm) resulted in significant upregulation of calponin, desmin, and smoothelin, in addition to the downregulation of intercellular adhesion molecule-1, tissue factor, interleukin-6, and monocyte chemoattractant protein-1. Further, our results allude to the mechanistic role of the RhoA/ROCK pathway and caveolin-1 in altered cellular mechanotransduction pathways via differential matrix nanotopography and stiffness. Notably, the nanopatterning of the stiffer substrata (1.1?GPa) resulted in the significant upregulation of RhoA, ROCK1, and ROCK2. This indicates that nanopatterning an 800_800_600?nm pattern on a stiff substratum may trigger the mechanical plasticity of vSMCs resulting in a hypercontractile vSMC phenotype, as observed in diabetes or hypertension. Given that matrix stiffness is an independent risk factor for cardiovascular disease and that CFL can create different matrix nanotopographic patterns with high pattern fidelity, we are poised to create a combinatorial library of arterial test beds, whether they are healthy, diseased, injured, or aged. Such high-throughput testing environments will pave the way for the evolution of the next generation of vascular scaffolds that can effectively crosstalk with the scaffold microenvironment and result in improved clinical outcomes.
| S-EPMC4137359 | biostudies-literature