Thyroid hormone induces artery smooth muscle cell proliferation: discovery of a new TRalpha1-Nox1 pathway.
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ABSTRACT:
SUBMITTER: Wang X
PROVIDER: S-EPMC2888973 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:The chronic phase of pulmonary arterial hypertension (PAH) is associated with vascular remodeling, especially thickening of the smooth muscle layer of large pulmonary arteries and muscularization of small pulmonary vessels, which normally have no associated smooth muscle. Serotonin (5-hydroxytryptamine, 5-HT) has been shown to induce proliferation and hypertrophy of pulmonary artery smooth muscle cells (PASMC), and may be important for in vivo pulmonary vascular remodeling. Here, we show that 5-HT stimulates migration of pulmonary artery PASMC. Treatment with 5-HT for 16h increased migration of PASMC up to four-fold as monitored in a modified Boyden chamber assay. Increased migratory responses were associated with cellular morphological changes and reorganization of the actin cytoskeleton. 5-HT-induced alterations in morphology were previously shown in our laboratory to require cAMP [Lee SL, Fanburg BL. Serotonin produces a configurational change of cultured smooth muscle cells that is associated with elevation of intracellular cAMP. J Cell Phys 1992;150(2):396-405], and the 5-HT4 receptor was pharmacologically determined to be the primary activator of cAMP in bovine PASMC [Becker BN, Gettys TW, Middleton JP, Olsen CL, Albers FJ, Lee SL, et al. 8-Hydroxy-2-(di-n-propylamino)tetralin-responsive 5-hydroxytryptamine4-like receptor expressed in bovine pulmonary artery smooth muscle cells. Mol Pharmacol 1992;42(5):817-25]. We examined the role of the 5-HT4 receptor and cAMP in 5-HT-induced bovine PASMC migration. PASMC express 5-HT4 receptor mRNA, and a 5-HT4 receptor antagonist and a cAMP antagonist completely blocked 5-HT-induced cellular migration. Consistent with our previous report that a cAMP-dependent Cl(-) channel is required for 5-HT-induced morphological changes in PASMC, phenylanthranilic acid, a Cl(-) channel blocker, inhibited actin cytoskeletal reorganization and migration produced by 5-HT. We conclude that 5-HT stimulates PASMC migration and associated cytoskeletal reorganization through the 5-HT4 receptor and cAMP activation of a chloride channel.
| S-EPMC1831537 | biostudies-literature
Project description:PurposeThe migration and proliferation of vascular smooth muscle cells play crucial roles in the development of atherosclerotic lesions. This study examined the effects of fatty acid binding protein 4 (FABP4), an adipokine that is associated with cardiovascular risk, endothelial dysfunction and proinflammatory effects, on the migration and proliferation of human coronary artery smooth muscle cells (HCASMCs).Methods and resultsA DNA 5-bromo-2'-deoxy-uridine (BrdU) incorporation assay indicated that FABP4 significantly induced the dose-dependent proliferation of HCASMCs with a maximum stimulatory effect at 120 ng/ml (13% vs. unstimulated cells, p<0.05). An anti-FABP4 antibody (40 ng/ml) significantly inhibited the induced cell proliferation, demonstrating the specificity of the FABP4 proliferative effect. FABP4 significantly induced HCASMC migration in a dose-dependent manner with an initial effect at 60 ng/ml (12% vs. unstimulated cells, p<0.05). Time-course studies demonstrated that FABP4 significantly increased cell migration compared with unstimulated cells from 4 h (23%vs. 17%, p<0.05) to 12 h (74%vs. 59%, p<0.05). Pretreatment with LY-294002 (5 µM) and PD98059 (10 µM) blocked the FABP4-induced proliferation and migration of HCASMCs, suggesting the activation of a kinase pathway. On a molecular level, we observed an up-regulation of the MAPK pathway without activation of Akt. We found that FABP4 induced the active forms of the nuclear transcription factors c-jun and c-myc, which are regulated by MAPK cascades, and increased the expression of the downstream genes cyclin D1 and MMP2, CCL2, and fibulin 4 and 5, which are involved in cell cycle regulation and cell migration.ConclusionsThese findings indicate a direct effect of FABP4 on the migration and proliferation of HCASMCs, suggesting a role for this adipokine in vascular remodelling. Taken together, these results demonstrate that the FABP4-induced DNA synthesis and cell migration are mediated primarily through a MAPK-dependent pathway that activates the transcription factors c-jun and c-myc in HCASMCs.
| S-EPMC3843707 | biostudies-literature
Project description:Pulmonary Arterial Hypertension (PAH) is a progressive devastating disease characterized by excessive proliferation of the Pulmonary Arterial Smooth Muscle Cells (PASMCs). Studies suggest that PAH and cancers share an apoptosis-resistant state featuring excessive cell proliferation. MicroRNA-206 (miR-206) is known to regulate proliferation and is implicated in various types of cancers. However, the role of miR-206 in PAH has not been studied. In this study, it is hypothesized that miR-206 could play a role in the proliferation of PASMCs. In the present study, the expression patterns of miR-206 were investigated in normal and hypertensive mouse PASMCs. The effects of miR-206 in modulating cell proliferation, apoptosis and smooth muscle cell markers in human pulmonary artery smooth muscle cells (hPASMCs) were investigated in vitro. miR-206 expression in mouse PASMCs was correlated with an increase in right ventricular systolic pressure. Reduction of miR-206 levels in hPASMCs causes increased proliferation and reduced apoptosis and these effects were reversed by the overexpression of miR-206. miR-206 over expression also increased the levels of smooth muscle cell differentiation markers ?-smooth muscle actin and calponin implicating its importance in the differentiation of SMCs. miR-206 overexpression down regulated Notch-3 expression, which is key a factor in PAH development. These results suggest that miR-206 is a potential regulator of proliferation, apoptosis and differentiation of PASMCs, and that it could be used as a novel treatment strategy in PAH.
| S-EPMC3468623 | biostudies-literature
Project description:Baicalin, a flavonoid compound purified from the dry roots of Scutellaria baicalensis Georgi, has been shown to possess various pharmacological actions. Previous studies have revealed that baicalin inhibits the growth of cancer cells through the induction of apoptosis. Pulmonary arterial hypertension (PAH) is a devastating disease characterized by enhanced pulmonary artery smooth muscle cell (PASMCs) proliferation and suppressed apoptosis. However, the potential mechanism of baicalin in the regulation of PASMC proliferation and the prevention of cardiovascular diseases remains unexplored. To test the effects of baicalin on hypoxia, we used rats treated with or without baicalin (100 mg·kg?¹ each rat) at the beginning of the third week after hypoxia. Hemodynamic and pulmonary pathomorphology data showed that right ventricular systolic pressures (RVSP), the weight of the right ventricle/left ventricle plus septum (RV/LV + S) ratio and the medial width of pulmonary arterioles were much higher in chronic hypoxia. However, baicalin treatment repressed the elevation of RVSP, RV/LV + S and attenuated the pulmonary vascular structure remodeling (PVSR) of pulmonary arterioles induced by chronic hypoxia. Additionally, baicalin (10 and 20 ?mol·L?¹) treatment suppressed the proliferation of PASMCs and attenuated the expression of hypoxia-inducible factor-? (HIF-?) under hypoxia exposure. Meanwhile, baicalin reversed the hypoxia-induced reduction of p27 and increased AKT/protein kinase B phosphorylation p-AKT both in vivo and in vitro. These results suggested that baicalin could effectively attenuate PVSR and hypoxic pulmonary hypertension.
| S-EPMC4057725 | biostudies-literature
Project description:Studies were undertaken to examine any role for the hepcidin/ferroportin axis in proliferative responses of human pulmonary artery smooth muscle cells (hPASMCs). Entirely novel findings have demonstrated the presence of ferroportin in hPASMCs. Hepcidin treatment caused increased proliferation of these cells most likely by binding ferroportin resulting in internalisation and cellular iron retention. Cellular iron content increased with hepcidin treatment. Stabilisation of ferroportin expression and activity via intervention with the therapeutic monoclonal antibody LY2928057 reversed proliferation and cellular iron accumulation. Additionally, IL-6 treatment was found to enhance proliferation and iron accumulation in hPASMCs; intervention with LY2928057 prevented this response. IL-6 was also found to increase hepcidin transcription and release from hPASMCs suggesting a potential autocrine response. Hepcidin or IL-6 mediated iron accumulation contributes to proliferation in hPASMCs; ferroportin mediated cellular iron excretion limits proliferation. Haemoglobin also caused proliferation of hPASMCs; in other novel findings, CD163, the haemoglobin/haptoglobin receptor, was found on these cells and offers a means for cellular uptake of iron via haemoglobin. Il-6 was also found to modulate CD163 on these cells. These data contribute to a better understanding of how disrupted iron homeostasis may induce vascular remodelling, such as in pulmonary arterial hypertension.
| S-EPMC6113242 | biostudies-literature
Project description:ObjectvesTransient receptor potential vanilloid 3 (TRPV3) is a member of the TRP channels family of Ca2+ -permeant cation channels. In this study, we aim to investigate the role of TRPV3 in pulmonary vascular remodeling and PASMCs proliferation under hypoxia.Materials and methodsThe expression of TRPV3 was evaluated in patients with pulmonary arterial hypertension (PAH) and hypoxic rats, using hematoxylin and eosin (H&E) and immunohistochemistry. In vitro, MTT assay, flow cytometry, Western blotting and immunofluorescence were performed to investigate the effects of TRPV3 on proliferation of PASMCs.ResultsWe found that, in vivo, the expression of TRPV3 was increased in patients with PAH and hypoxic rats. Right ventricular hypertrophy measurements and pulmonary pathomorphology data show that the ratio of the heart weight/tibia length (HW/TL), the right ventricle/left ventricle plus septum (RV/LV+S) and the medial width of the pulmonary artery were increased in chronic hypoxic rats. Moreover, the expression of proliferating cell nuclear antigen (PCNA), Cyclin D, Cyclin E and Cyclin A, phospho-CaMKII (p-CaMKII) were induced by hypoxia. In vitro, we revealed that hypoxia promoted PASMCs viability, increased the expression of PCNA, Cyclin D, Cyclin E, Cyclin A p-CaMKII, made more cells from G0 /G1 phase to G2 /M + S phase, enhanced the microtubule formation, and increased [Ca2+ ]i , which could be suppressed by Ruthenium Red, an inhibitor of TRPV3, and TRPV3 silencing has similar effects. Furthermore, the up-regulated expression of PCNA, Cyclin D, Cyclin E and Cyclin A, the increased number of cells in G2 /M and S phase, and the enhanced activation and expression of PI3K and AKT proteins induced by hypoxia and in presence of carvacrol (an agonist of TRPV3), was significantly attenuated by incubation of LY 294002, a specific inhibitor for PI3K/AKT.ConclusionsThese findings suggest that TRPV3 is involved in hypoxia-induced pulmonary vascular remodeling and promotes proliferation of PASMCs and the effect is, at least in part, mediated via the PI3K/AKT pathway.
| S-EPMC6528857 | biostudies-literature
Project description:BackgroundRecent studies have demonstrated that the activation of NADPH oxidase 1 (Nox1) plays an important role in the control of reactive oxygen species and their involvement in vascular physiology and pathophysiology. In order to function properly, Nox1 needs to be available in an optimal state, where it is ready to respond appropriately and efficiently to upstream signals. It must also be able to return quickly to this state as soon as the input signal disappears. While Nox1 activation has been discussed extensively in recent years, mechanisms for enzyme disassembly and proper subunit recovery have not received the same attention and therefore require investigation.ResultsWe study the Nox1 system in vascular smooth smucle cells and propose four potential disassembly mechanisms. The analysis consists primarily of large-scale Monte-Carlo simulations whose results are essentially independent of specific parameter values. The computational analysis shows that a specific profile of subunit concentrations is crucial for optimal functioning and responsiveness of the system to input signals. Specifically, free p47(phox) and inactive Rac1 should be dominant under unstimulated resting conditions, and the proteolytic disassembly pathway should have a low flux, as it is relatively inefficient. The computational results also reveal that the optimal design of the three subunit recovery pathways depends on the intracellular settings of the pathway and that the response speeds of key reversible reactions within the pathway are of great importance.ConclusionsOur results provide a systematic basis for understanding the dynamics of Nox1 and yield novel insights into its crucially important disassembly mechanisms. The rigorous comparisons of the relative importance of four potential disassembly pathways demonstrate that disassembly via proteolysis is the least effective mechanism. The relative significance of the other three recovery pathways varies among different scenarios. It is greatly affected by the required response speed of the system and depends critically on appropriate flux balances between forward and reverse reactions. Our findings are predictive and pose novel hypotheses that should be validated with future experiments.
| S-EPMC3606394 | biostudies-literature
Project description:AimsReactive oxygen species (ROS)-mediated intracellular signalling is well described in the vasculature, yet the precise roles of ROS in paracrine signalling are not known. Studies implicate interstitial ROS hydrogen peroxide (H(2)O(2)) in vascular disease, and plasma H(2)O(2) levels in the micromolar range are detectable in animal models and humans with hypertension. Recently, H(2)O(2) was shown to cross biological membranes of non-vascular cells via aquaporin (Aqp) water channels. Previous findings suggest that H(2)O(2) activates NADPH oxidase (Nox) enzymes in vascular cells and apoptosis signal-regulating kinase 1 (Ask1) in non-vascular cells. We hypothesized that extracellular H(2)O(2) induces smooth muscle cell (SMC) hypertrophy by a mechanism involving Aqp1, Nox1, and Ask1.Methods and resultsTreatment of rat aortic SMCs (rASMC) with exogenous H(2)O(2) resulted in a concentration-dependent increase in Nox-derived superoxide (O(2)(•-)), determined by L-012 chemiluminescence, cytochrome c and electron paramagnetic resonance. Nox1 was verified as the source of O(2)(·-) by siRNA. Aqp1 siRNA attenuated H(2)O(2) cellular entry and H(2)O(2)-induced O(2)(•-) production. H(2)O(2) treatment increased Ask1 activation and induced rASMC hypertrophy in a Nox1-dependent mechanism. Adenoviral-dominant-negative Ask1 attenuated H(2)O(2)-induced rASMC hypertrophy and adenoviral overexpression of Ask1 augmented it.ConclusionOur results demonstrate for the first time that extracellular H(2)O(2), at pathophysiological concentrations, stimulates rASMC Nox1-derived O(2)(•-), subsequent Ask1 activation and SMC hypertrophy. The data demonstrate a novel pathway by which H(2)O(2) enters vascular cells via aquaporins and activates Nox, leading to hypertrophy, and provide multiple novel targets for combinatorial therapeutics development targeting hypertrophy and vascular disease.
| S-EPMC3527765 | biostudies-literature
Project description:ObjectivesPulmonary arterial hypertension (PAH) is a fast progressing vascular disease characterized by uncontrolled cell proliferation of pulmonary artery smooth muscle cells (PASMCs). Some studies have suggested that PAH and cancers share an apoptosis-resistant state, featuring excessive cell proliferation. The miR-34 family consists of tumour-suppressive miRNAs, and its reduced expression has been reported in numerous cancers; however, its role in hypoxia-induced PAH has not been previously studied.Materials and methodsmiR-34 family expression was evaluated in a rat model with hypoxia and in cultured hypoxic PASMCs, using real-time quantitative PCR (RT-qPCR). Function of miR-34 family was assessed by transfecting miR-34 mimics and inhibitors. Dual luciferase reporter gene assays, RT-qPCR and Western blotting were performed to validate target genes of miR-34.ResultsSignificant down-regulation of miR-34a in hypoxic lung tissue, pulmonary artery and PASMCs was identified and then effects of miR-34a in modulating cell proliferation in human pulmonary artery smooth muscle cells (hPASMCs) was investigated in vitro. Reduction of miR-34a levels in hPASMCs caused increased proliferation and these effects were reversed by overexpression of miR-34a. miR-34a overexpression down-regulated platelet-derived growth factor receptor alpha (PDGFRA) expression, which is a key factor in PAH development. These results suggest that miR-34a is a potential regulator of proliferation in PASMCs, and that it could be used as a novel treatment strategy in PAH.
| S-EPMC6496014 | biostudies-literature
Project description:Background: Proliferation and migration of smooth muscle cells in the coronary artery contribute to the deterioration of coronary artery disease (CAD). Aim: This research was designed to study the function of Shexiang Baoxin pills (SBPs) on the proliferation and migration of human coronary artery smooth muscle cells (HCASMCs) and their mechanism. Methods: Oxidized low-density lipoprotein (ox-LDL) was applied to stimulate the proliferation and migration of HCASMCs. The function of ox-LDL and SBP on HCASMCs was evidenced by the cell counting kit-8 assay, cell cycle, and Transwell assay. Network pharmacology was employed to predict the potential targets and pathways of SBP on CAD. Western blot assay and molecular docking were conducted to validate the potential targets and pathways. Results: The current research revealed that 2.5 mg/L SBP significantly inhibited the proliferation and migration of HCASMCs. Besides, network pharmacology revealed 11 candidate targets. Molecular docking and Western blot assay validated that the activation of the top 2 targets STAT3 and MAPK14 was associated with the inhibition of HCASMCs. Moreover, the Western blot assay also detected that HCASMCs treated with ox-LDL promoted the phosphorylation of the PI3K/AKT/mTOR pathway, and SBP inhibited the activation of the PI3K/AKT/mTOR pathway in HCASMCs stimulated by ox-LDL. Conclusion: This study demonstrated that the treatment of CAD using SBP may result from the suppression of the proliferation and migration of HCASMCs. The mechanism of this function partly resulted from relieving the phosphorylation of targets STAT3 and MAPK14 and the PI3K/AKT/mTOR pathway. This study enhanced our comprehension of SBP and provides new targets for the treatment of CAD.
| S-EPMC8425485 | biostudies-literature