NF2 deficiency accelerates neointima hyperplasia following vascular injury via promoting YAP-TEAD1 interaction in vascular smooth muscle cells.
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ABSTRACT:
SUBMITTER: Sun X
PROVIDER: S-EPMC7288949 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:To investigate the functional role of the microRNA (miR)-15b/16 in vascular smooth muscle (SM) phenotypic modulation.We found that miR-15b/16 is one of the most abundant mRs expressed in contractile vascular smooth muscle cells (VSMCs). However, when contractile VSMCs get converted to a synthetic phenotype, miR-15b/16 expression is significantly reduced. Knocking down endogenous miR-15b/16 in VSMCs attenuates SM-specific gene expression but promotes VSMC proliferation and migration. Conversely, overexpression of miR-15b/16 promotes SM contractile gene expression while attenuating VSMC migration and proliferation. Consistent with this, overexpression of miR-15b/16 in a rat carotid balloon injury model markedly attenuates injury-induced SM dedifferentiation and neointima formation. Mechanistically, we identified the potent oncoprotein yes-associated protein (YAP) as a downstream target of miR-15b/16 in VSMCs. Reporter assays validated that miR-15b/16 targets YAP's 3' untranslated region. Moreover, overexpression of miR-15b/16 significantly represses YAP expression, whereas conversely, depletion of endogenous miR-15b/16 results in upregulation of YAP expression.These results indicate that miR-15b/16 plays a critical role in SM phenotypic modulation at least partly through targeting YAP. Restoring expression of miR-15b/16 would be a potential therapeutic approach for treatment of proliferative vascular diseases.
| S-EPMC4701035 | biostudies-literature
Project description:TEAD1 (TEA domain transcription factor 1), a transcription factor known for the functional output of Hippo signaling, is important for tumorigenesis. However, the role of TEAD1 in the development of vascular smooth muscle cell (VSMC) is unknown. To investigate cell-specific role of Tead1, we generated cardiomyocyte (CMC) and VSMC-specific Tead1 knockout mice. We found CMC/VSMC-specific deletion of Tead1 led to embryonic lethality by E14.5 in mice due to hypoplastic cardiac and vascular walls, as a result of impaired CMC and VSMC proliferation. Whole transcriptome analysis revealed that deletion of Tead1 in CMCs/VSMCs downregulated expression of muscle contractile genes and key transcription factors including Pitx2c and myocardin. In vitro studies demonstrated that PITX2c and myocardin rescued TEAD1-dependent defects in VSMC differentiation. We further identified Pitx2c as a novel transcriptional target of TEAD1, and PITX2c exhibited functional synergy with myocardin by directly interacting with myocardin, leading to augment the differentiation of VSMC. In summary, our study reveals a critical role of Tead1 in cardiovascular development in mice, but also identifies a novel regulatory mechanism, whereby Tead1 functions upstream of the genetic regulatory hierarchy for establishing smooth muscle contractile phenotype.
| S-EPMC7224394 | biostudies-literature
Project description:OBJECTIVE:Genome-wide studies showed that mutation in apoER2 (apolipoprotein E receptor-2) is additive with ?4 polymorphism in the APOE gene on cardiovascular disease risk in humans. ApoE or apoER2 deficiency also accelerates atherosclerosis lesion necrosis in hypercholesterolemic mice and promotes neointima formation after vascular injury. This study tests the hypothesis that apoE and apoER2 modulate vascular occlusive diseases through distinct mechanisms. Approach and Results: Carotid endothelial denudation induced robust neointima formation in both apoE-/- and apoER2-deficient Lrp8-/- mice. The intima in apoE-/- mice was rich in smooth muscle cells, but the intima in Lrp8-/- mice was cell-poor and rich in extracellular matrix. Vascular smooth muscle cells isolated from apoE-/- mice were hyperplastic whereas Lrp8-/- smooth muscle cells showed reduced proliferation but responded robustly to TGF (transforming growth factor)-?-induced fibronectin synthesis indicative of a senescence-associated secretory phenotype, which was confirmed by increased ?-galactosidase activity, p16INK4a immunofluorescence, and number of multinucleated cells. Western blot analysis of cell cycle-associated proteins showed that apoER2 deficiency promotes cell cycle arrest at the metaphase/anaphase. Coimmunoprecipitation experiments revealed that apoER2 interacts with the catalytic subunit of protein phosphatase 2A. In the absence of apoER2, PP2A-C (protein phosphatase 2A catalytic subunit) failed to interact with CDC20 (cell-division cycle protein 20) thus resulting in inactive anaphase-promoting complex and impaired cell cycle exit. CONCLUSIONS:This study showed that apoER2 participates in APC (anaphase-promoting complex)/CDC20 complex formation during mitosis, and its absence impedes cytokinesis abscission thereby accelerating premature cell senescence and vascular disease. This mechanism is distinct from apoE deficiency, which causes smooth muscle cell hyperplasia to accelerate vascular disease.
| S-EPMC6761011 | biostudies-literature
Project description:We have previously demonstrated that the transcription co-factor yes-associated protein 1 (YAP1) promotes vascular smooth muscle cell (VSMC) de-differentiation. Yet, the role and underlying mechanisms of YAP1 in neointima formation in vivo remain unclear. The goal of this study was to investigate the role of VSMC-expressed YAP1 in vascular injury-induced VSMC proliferation and delineate the mechanisms underlying its action. Experiments employing gain- or loss-of-function of YAP1 demonstrated that YAP1 promotes human VSMC proliferation. Mechanistically, we identified platelet-derived growth factor receptor beta (PDGFRB) as a novel YAP1 target gene that confers the YAP1-dependent hyper-proliferative effects in VSMCs. Furthermore, we identified TEA domain transcription factor 1 (TEAD1) as a key transcription factor that mediates YAP1-dependent PDGFRβ expression. ChIP assays demonstrated that TEAD1 is enriched at a PDGFRB gene enhancer. Luciferase reporter assays further demonstrated that YAP1 and TEAD1 co-operatively activate the PDGFRB enhancer. Consistent with these observations, we found that YAP1 expression is upregulated after arterial injury and correlates with PDGFRβ expression and VSMC proliferation in vivo. Using a novel inducible SM-specific Yap1 knockout mouse model, we found that the specific deletion of Yap1 in adult VSMCs is sufficient to attenuate arterial injury-induced neointima formation, largely due to inhibited PDGFRβ expression and VSMC proliferation. Our study unravels a novel mechanism by which YAP1/TEAD1 promote VSMC proliferation via transcriptional induction of PDGFRβ, thereby enhancing PDGF-BB downstream signaling and promoting neointima formation.
| S-EPMC8217227 | biostudies-literature
Project description:Autophagy is triggered in vascular smooth muscle cells (VSMCs) of diseased arterial vessels. However, the role of VSMC autophagy in cardiovascular disease is poorly understood. Therefore, we investigated the effect of defective autophagy on VSMC survival and phenotype and its significance in the development of postinjury neointima formation and atherosclerosis. Tissue-specific deletion of the essential autophagy gene Atg7 in murine VSMCs (atg7-/- VSMCs) caused accumulation of SQSTM1/p62 and accelerated the development of stress-induced premature senescence as shown by cellular and nuclear hypertrophy, CDKN2A-RB-mediated G1 proliferative arrest and senescence-associated GLB1 activity. Transfection of SQSTM1-encoding plasmid DNA in Atg7+/+ VSMCs induced similar features, suggesting that accumulation of SQSTM1 promotes VSMC senescence. Interestingly, atg7-/- VSMCs were resistant to oxidative stress-induced cell death as compared to controls. This effect was attributed to nuclear translocation of the transcription factor NFE2L2 resulting in upregulation of several antioxidative enzymes. In vivo, defective VSMC autophagy led to upregulation of MMP9, TGFB and CXCL12 and promoted postinjury neointima formation and diet-induced atherogenesis. Lesions of VSMC-specific atg7 knockout mice were characterized by increased total collagen deposition, nuclear hypertrophy, CDKN2A upregulation, RB hypophosphorylation, and GLB1 activity, all features typical of cellular senescence. To conclude, autophagy is crucial for VSMC function, phenotype, and survival. Defective autophagy in VSMCs accelerates senescence and promotes ligation-induced neointima formation and diet-induced atherogenesis, implying that autophagy inhibition as therapeutic strategy in the treatment of neointimal stenosis and atherosclerosis would be unfavorable. Conversely, stimulation of autophagy could be a valuable new strategy in the treatment of arterial disease.
| S-EPMC4824610 | biostudies-literature
Project description:OBJECTIVE:hnRNPA1 (heterogeneous nuclear ribonucleoprotein A1) plays a variety of roles in gene expression. However, little is known about the functional involvement of hnRNPA1 in vascular smooth muscle cell (VSMC) function and neointima hyperplasia. In this study, we have attempted to investigate the functional roles of hnRNPA1 in the contexts of VSMC function, injury-induced vessel remodeling, and human atherosclerotic lesions, as well as discern the molecular mechanisms involved. APPROACH AND RESULTS: hnRNPA1 expression levels were consistently modulated during VSMC phenotype switching and neointimal lesion formation induced by wire injury. Functional studies showed that VSMC-specific gene expression, proliferation, and migration were regulated by hnRNPA1. Our data show that hnRNPA1 exerts its effects on VSMC functions through modulation of IQGAP1 (IQ motif containing GTPase activating protein 1). Mechanistically, hnRNPA1 regulates IQGAP1 mRNA degradation through 2 mechanisms: upregulating microRNA-124 (miR-124) and binding to AU-rich element of IQGAP1 gene. Further evidence suggests that hnRNPA1 upregulates miR-124 by modulating miR-124 biogenesis and that IQGAP1 is the authentic target gene of miR-124. Importantly, ectopic overexpression of hnRNPA1 greatly reduced VSMC proliferation and inhibited neointima formation in wire-injured carotid arteries. Finally, lower expression levels of hnRNPA1 and miR-124, while higher expression levels of IQGAP1, were observed in human atherosclerotic lesions. CONCLUSIONS:Our data show that hnRNPA1 is a critical regulator of VSMC function and behavior in the context of neointima hyperplasia, and the hnRNPA1/miR-124/IQGAP1 regulatory axis represents a novel therapeutic target for the prevention of cardiovascular diseases.
| S-EPMC5660626 | biostudies-literature
Project description:BACKGROUND:MicroRNA miR-214 has been implicated in many biological cellular functions, but the impact of miR-214 and its target genes on vascular smooth muscle cell (VSMC) proliferation, migration, and neointima smooth muscle cell hyperplasia is unknown. METHODS AND RESULTS:Expression of miR-214 was closely regulated by different pathogenic stimuli in VSMCs through a transcriptional mechanism and decreased in response to vascular injury. Overexpression of miR-214 in serum-starved VSMCs significantly decreased VSMC proliferation and migration, whereas knockdown of miR-214 dramatically increased VSMC proliferation and migration. Gene and protein biochemical assays, including proteomic analyses, showed that NCK associated protein 1 (NCKAP1)-a major component of the WAVE complex that regulates lamellipodia formation and cell motility-was negatively regulated by miR-214 in VSMCs. Luciferase assays showed that miR-214 substantially repressed wild-type but not the miR-214 binding site mutated version of NCKAP1 3' untranslated region luciferase activity in VSMCs. This result confirmed that NCKAP1 is the functional target of miR-214 in VSMCs. NCKAP1 knockdown in VSMCs recapitulates the inhibitory effects of miR-214 overexpression on actin polymerization, cell migration, and proliferation. Data from cotransfection experiments also revealed that inhibition of NCKAP1 is required for miR-214-mediated lamellipodia formation, cell motility, and growth. Importantly, locally enforced expression of miR-214 in the injured vessels significantly reduced NCKAP1 expression levels, inhibited VSMC proliferation, and prevented neointima smooth muscle cell hyperplasia after injury. CONCLUSIONS:We uncovered an important role of miR-214 and its target gene NCKAP1 in modulating VSMC functions and neointima hyperplasia. Our findings suggest that miR-214 represents a potential therapeutic target for vascular diseases.
| S-EPMC5210428 | biostudies-literature
Project description:OBJECTIVE:Smooth muscle cells (SMCs) contribute to neointima formation after vascular injury. Although ?-catenin expression is induced after injury, whether its function is essential in SMCs for neointimal growth is unknown. Moreover, although inhibitors of ?-catenin have been developed, their effects on SMC growth have not been tested. We assessed the requirement for SMC ?-catenin in short-term vascular homeostasis and in response to arterial injury and investigated the effects of ?-catenin inhibitors on vascular SMC growth. APPROACH AND RESULTS:We used an inducible, conditional genetic deletion of ?-catenin in SMCs of adult mice. Uninjured arteries from adult mice lacking SMC ?-catenin were indistinguishable from controls in terms of structure and SMC marker gene expression. After carotid artery ligation, however, vessels from mice lacking SMC ?-catenin developed smaller neointimas, with lower neointimal cell proliferation and increased apoptosis. SMCs lacking ?-catenin showed decreased mRNA expression of Mmp2, Mmp9, Sphk1, and S1pr1 (genes that promote neointima formation), higher levels of Jag1 and Gja1 (genes that inhibit neointima formation), decreased Mmp2 protein expression and secretion, and reduced cell invasion in vitro. Moreover, ?-catenin inhibitors PKF118-310 and ICG-001 limited growth of mouse and human vascular SMCs in a dose-dependent manner. CONCLUSIONS:SMC ?-catenin is dispensable for maintenance of the structure and state of differentiation of uninjured adult arteries, but is required for neointima formation after vascular injury. Pharmacological ?-catenin inhibitors hinder growth of human vascular SMCs. Thus, inhibiting ?-catenin has potential as a therapy to limit SMC accumulation and vascular obstruction.
| S-EPMC5408313 | biostudies-literature
Project description:Mitogen-activated protein kinase pathways play an important role in neointima formation secondary to vascular injury, in part by promoting proliferation of vascular smooth muscle cells (VSMC). Mixed-lineage kinase 3 (MLK3) is a mitogen-activated protein kinase kinase kinase that activates multiple mitogen-activated protein kinase pathways and has been implicated in regulating proliferation in several cell types. However, the role of MLK3 in VSMC proliferation and neointima formation is unknown. The aim of this study was to determine the function of MLK3 in the development of neointimal hyperplasia and to elucidate the underlying mechanisms.Neointima formation was analyzed after endothelial denudation of carotid arteries from wild-type and MLK3-deficient mice. MLK3 deficiency promoted injury-induced neointima formation and increased proliferation of primary VSMC derived from aortas isolated from MLK3-deficient mice compared with wild-type mice. Furthermore, MLK3 deficiency increased the activation of p63Rho guanine nucleotide exchange factor, RhoA, and Rho kinase in VSMC, a pathway known to promote neointimal hyperplasia, and reconstitution of MLK3 expression attenuated Rho kinase activation. Furthermore, cJun NH2-terminal kinase activation was decreased in MLK3-deficient VSMC, and proliferation of wild-type but not MLK3 knockout cells treated with a cJun NH2-terminal kinase inhibitor was attenuated.We demonstrate that MLK3 limits RhoA activation and injury-induced neointima formation by binding to and inhibiting the activation of p63Rho guanine nucleotide exchange factor, a RhoA activator. In MLK3-deficient cells, activation of p63Rho guanine nucleotide exchange factor proceeds in an unchecked manner, leading to a net increase in RhoA pathway activation. Reconstitution of MLK3 expression restores MLK3/p63Rho guanine nucleotide exchange factor interaction, which is attenuated by feedback from activated cJun NH2-terminal kinase.
| S-EPMC4084683 | biostudies-literature
Project description:BackgroundAccelerated smooth muscle cell (SMC) proliferation is the primary cause of intimal hyperplasia (IH) following vascular interventions. Forkhead Box M1 (FOXM1) is considered a proliferation-associated transcription factor. However, the presence and role of FOXM1 in IH following vascular injury have not been determined.ObjectiveWe examined the expression of FOXM1 in balloon-injured rat carotid arteries and investigated the effect of FOXM1 inhibition in SMCs and on the development of IH.Methods and resultsFOXM1 was detected by immunofluorescent staining in balloon-injured rat carotid arteries where we observed an upregulation at day 7, 14, and 28 compared to uninjured controls. Immunofluorescence staining revealed FOXM1 coincided with proliferating cell nuclear antigen (PCNA). FOXM1 was also detectable in human carotid plaque samples. Western blot showed an upregulation of FOXM1 protein in serum-stimulated SMCs. Inhibition of FOXM1 using siRNA or chemical inhibition led to the induction of apoptosis as measured by flow cytometry and western blot for cleaved caspase 3. Perturbations in survival signaling were measured by western blot following FOXM1 inhibition, which showed a decrease in phosphorylated AKT and β-catenin. The chemical inhibitor thiostrepton was delivered by intraperitoneal injection in rats that underwent balloon injury and led to reduced intimal thickening compared to DMSO controls.ConclusionsFOXM1 is an important molecular mediator of IH that contributes to the proliferation and survival of SMCs following vascular injury.
| S-EPMC7303564 | biostudies-literature