Vascular smooth muscle cell derived from iPS cell of Moyamoya disease - Comparative characterization with endothelial cell transcriptome
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ABSTRACT: Transcriptome analysis of vascular smooth muscle cells differentiated from iPS-derived neural crest stem cells in Moyamoya disease Moyamoya disease (MMD) is a rare cerebrovascular disorder characterized by steno-occlusive changes in the cerebral arteries at the base of the brain with unknown etiology, although histopathological features have demonstrated as fibrocellular thickening of the intima and medial thinning on the steno-occlusive arteries. However, the pathophysiology of proliferating cells in the thickened intima is still obscure. Furthermore, biological features of the vascular smooth muscle cells are unclear in MMD. Here, we aimed to analyze whole genome gene expression profile in VSMC using induced pluripotent stem (iPS) cell line. We generated iPS cell line from the blood of MMD with RNF213 R4810K risk allele (rs112735431) or healthy control without the risk allele. VSMCs were differentiated from iPS-derived neural crest stem cells. As a result, we successfully established cranio-cervical region specific VSMC confirmed by immunocytochemistry. Biological cellular features, including cellular proliferation, migration, and contraction ability were similar in VSMCs between MMD and control. Genome-wide gene expression analysis showed similar transcriptome profile in the VSMCs between MMD and control. Differential gene expression analysis in MMD-VSMC revealed 6 differentially expressed genes (4 upregulated, 2 down regulated in MMD), including decorin (DCN, upregulated in MMD), playing an inhibitory role in angiogenesis. In conclusion, VSMCs are not impaired in cellular function with similar transcriptome profile in MMD compared to healthy control. Since many previous studies have shown impaired EC features in MMD, our study suggests EC may play more role in the vascular pathogenesis in MMD rather than VSMC.
Project description:Vascular smooth muscle cell (VSMC) dysregulation is a hallmark of vascular disease, including atherosclerosis. In particular, the majority of cells within atherosclerotic lesions are generated from pre-existing VSMCs and a clonal nature has been documented for VSMC-derived cells in multiple disease models. However, the mechanisms underlying the generation of oligoclonal lesions and the phenotype of proliferating VSMCs are unknown.Here we analyse clonal dynamics in multi-color lineage-traced animals over time after vessel injury to understand the cellular mechanisms underlying clonal VSMC expansion in disease.We demonstrate that VSMC proliferation is initiated in a small fraction of VSMCs that initially expand clonally in the medial layer and then migrate to form the oligoclonal neointima. Selective activation of VSMC proliferation also occurs in vitro, suggesting that this is a cell-autonomous feature. Mapping of VSMC trajectories using single-cell RNA-sequencing reveals a continuum of cellular states after injury and suggests that VSMC proliferation initiates in cells that have downregulated the contractile phenotype and show evidence of pronounced phenotypic switching. We show that proliferation is associated with induced expression of stem cell antigen 1 (SCA1) and the expression signature previously identified in SCA1+ VSMCs in healthy arteries. A remarkably increased proliferation of SCA1+ VSMCs, directly validated in functional assays, indicates that SCA1+ VSMCs act as "first responders" in vascular injury. Early atherosclerotic lesions also had clonal VSMC contribution and we show that the proliferation-associated injury response is conserved in plaque VSMCs, extending these findings to atherosclerosis. Finally, we identify VSMCs in healthy human arteries that correspond to the SCA1+ state in mouse VSMCs and show that genes identified as differentially expressed in this human VSMC subpopulation are enriched for genes showing genetic association with cardiovascular disease. We show that cell-intrinsic, selective VSMC activation drives clonal proliferation after injury and in atherosclerosis. Our study suggests that healthy mouse and human arteries contain VSMCs characterised by expression of disease-associated genes that are predisposed for proliferation. Targeting such "first responder" cells in patients undergoing vascular surgery could effectively prevent injury-associated VSMC activation and neoatherosclerosis.
Project description:Moyamoya disease (MMD) is a cerebrovascular disease characterized by progressive stenosis of the intracranial internal carotid arteries and their proximal branches. However, the etiology of this rare disease remains widely unknown. Serum microRNA (miRNA) profiles have been screened to identify novel biomarkers for disease diagnosis and prognosis. Here, we identified important serum miRNAs that might play important roles in contributing to MMD pathogenesis through microarray analysis. 10 MMD patients and 10 controls were consecutively recruited at Shanghai Changhai Hospital. Five-ml venous blood was collected from each participant and separated into serum and cellular fractions. We pooled serum samples from 10 MMD patients and 10 controls. Agilent Human 8 x 60K miRNA Array was performed on the two pooled samples.
Project description:Moyamoya disease (MMD) is a cerebrovascular disease characterized by progressive stenosis of the intracranial internal carotid arteries and their proximal branches. However, the etiology of this rare disease remains widely unknown. Serum microRNA (miRNA) profiles have been screened to identify novel biomarkers for disease diagnosis and prognosis. Here, we identified important serum miRNAs that might play important roles in contributing to MMD pathogenesis through microarray analysis.
Project description:Vascular smooth muscle cells (VSMCs) possess significant phenotypic plasticity, shifting between a contractile phenotype and a synthetic state for vascular repair/remodelling. Dysregulated VSMC transformation, marked by excessive proliferation and migration, primarily drives intimal hyperplasia. N6-methyladenosine (m6A), the most prevalent RNA modification in eukaryotes, plays a critical role in gene expression regulation; however, its impact on VSMC plasticity is not fully understood. This research investigates the alterations in m6A modification and its regulatory factors during VSMC phenotypic shifts and their influence on intimal hyperplasia. We demonstrate that METTL14, crucial for m6A deposition, significantly promotes VSMC dedifferentiation. METTL14 expression, initially negligible, is elevated in synthetic VSMC cultures, post-injury neointimal VSMCs, and human restenotic arteries. Reducing Mettl14 levels in mouse primary VSMCs decreases pro- synthetic genes, suppressing their proliferation and migration. m6A-RIP-seq profiling shows key VSMC gene networks undergo altered m6A regulation in Mettl14-deficient cells. Mettl14 enhances Klf4 and Serpine1 expression through increased m6A deposition. Local Mettl14 knockdown significantly curbs neointimal formation post-arterial injury, and reducing Mettl14 in hyperplastic arteries halts further neointimal development. We found that Mettl14 is a pivotal regulator of VSMC dedifferentiation, influencing Klf4- and Serpine1- mediated phenotypic conversion. Inhibiting Mettl14 is a viable strategy for preventing restenosis and halting restenotic occlusions
Project description:Vascular smooth muscle cells (VSMCs) possess significant phenotypic plasticity, shifting between a contractile phenotype and a synthetic state for vascular repair/remodelling. Dysregulated VSMC transformation, marked by excessive proliferation and migration, primarily drives intimal hyperplasia. N6-methyladenosine (m6A), the most prevalent RNA modification in eukaryotes, plays a critical role in gene expression regulation; however, its impact on VSMC plasticity is not fully understood. This research investigates the alterations in m6A modification and its regulatory factors during VSMC phenotypic shifts and their influence on intimal hyperplasia. We demonstrate that METTL14, crucial for m6A deposition, significantly promotes VSMC dedifferentiation. METTL14 expression, initially negligible, is elevated in synthetic VSMC cultures, post-injury neointimal VSMCs, and human restenotic arteries. Reducing Mettl14 levels in mouse primary VSMCs decreases pro- synthetic genes, suppressing their proliferation and migration. m6A-RIP-seq profiling shows key VSMC gene networks undergo altered m6A regulation in Mettl14-deficient cells. Mettl14 enhances Klf4 and Serpine1 expression through increased m6A deposition. Local Mettl14 knockdown significantly curbs neointimal formation post-arterial injury, and reducing Mettl14 in hyperplastic arteries halts further neointimal development. We found that Mettl14 is a pivotal regulator of VSMC dedifferentiation, influencing Klf4- and Serpine1- mediated phenotypic conversion. Inhibiting Mettl14 is a viable strategy for preventing restenosis and halting restenotic occlusions
Project description:We applied RNA-Seq to analyze the effects of silencing of Thoc2 or Thoc5, two components of the THO complex, in cultured VSMC. The result revealed that Thoc5 silencing closely resembled the gene expression changes induced upon PDGF-BB/PDGF-DD treatments in cultured VSMCs. Mechanistically, our RIP-Seq data revealed both Thoc2 and Thoc5 preferentially interacted with VSMC marker gene mRNAs and mediated their expression. Interestingly, mRNAs that lost Thoc2 or Thoc5 binding during VSMC dedifferentiation were enriched for genes important for VSMC identity. In addition, silencing of Thoc2 or Thoc5 led to dedifferentiation of VSMCs in vitro, characterized by decreased VSMC marker gene expression and increased migration and proliferation. Furthermore, we performed immuno-histochemical staining against Thoc2 and Thoc5, and found a dramatic reduction in their expression in human arteries undergoing carotid endarterectomy (CEA) compared to normal internal mammary arteries (IMA). Notably, Thoc5 overexpression in injured rat carotid arteries significantly repressed loss of VSMC marker gene expression and neointima formation. Together, our data introduce dynamic binding of THO to VSMC marker gene mRNAs as a novel mechanism contributing to VSMC fate decisions, and imply Thoc5 as a potential intervention node for vascular diseases.
Project description:Vascular inflammation underlies cardiovascular disease. Vascular smooth muscle cells (VSMCs) upregulate selective genes, including matrix metalloproteinases (MMPs) and pro-inflammatory cytokines in response to local inflammation, which directly contribute to vascular disease and adverse clinical outcome. Identification of factors controlling VSMC responses to inflammation is therefore of considerable therapeutic importance. Here, we determine the role of H3K9me2, a repressive epigenetic mark that is reduced in atherosclerotic lesions, in regulating the VSMC inflammatory response. We used VSMC-lineage tracing to detect reduced H3K9me2 levels in VSMCs of arteries after injury and in atherosclerosis. Intriguingly, chromatin immunoprecipitation revealed H3K9me2 enrichment at a subset of inflammation-responsive gene promoters, including MMP3, MMP9, MMP12 and IL6, in mouse and human VSMCs. Inhibition of G9A/GLP, the primary enzymes responsible for H3K9me2, significantly potentiated inflammation-induced gene induction in vitro and in vivo without altering NFkB and MAPK signalling. Rather, reduced G9A/GLP activity enhanced inflammation-induced binding of transcription factors NFkB-p65 and cJUN to H3K9me2 target gene promoters MMP3 and IL6. Taken together, these results suggest that promoter-associated H3K9me2 directly attenuates the induction of target genes in response to inflammation in human VSMCs. This study implicates H3K9me2 in regulating the pro-inflammatory VSMC phenotype. Our findings suggest that reduced H3K9me2 in disease allows complete binding of NFkB and AP-1 transcription factors at specific inflammation-responsive genes to augment pro-inflammatory stimuli in VSMC. Since increased MMP and IL6 activity are features of vascular disease, H3K9me2-regulation may be a novel target for clinical intervention.
Project description:Neointimal hyperplasia (NIH), driven by vascular smooth muscle cell (VSMC) dysfunction, is a key factor in vascular diseases like atherosclerosis and restenosis. While Nrf3 is known to regulate VSMC differentiation, its role in NIH remains unclear. Using transcriptomic data, Nrf3 knockout mice (global), we assessed Nrf3’s impact on VSMC function and NIH. We identified Trim5, a gene linked to coronary artery disease, as a downstream target of Nrf3, which promotes autophagy in VSMCs and injured arteries, enhancing VSMC dysfunction and NIH. Nrf3 overexpression increased VSMC proliferation, migration, and inflammation, while deletion or knockdown had the opposite effects. Nrf3-/- and Nrf3ΔSMC mice showed reduced VSMC accumulation and attenuated NIH after vascular injury. These findings highlight Nrf3 as a novel modulator of VSMC dysfunction and injury-induced NIH, with potential for therapeutic targeting of the Nrf3-Trim5 axis to treat NIH-related vascular diseases.
Project description:Loss of contractility and acquisition of an epithelial phenotype of vascular smooth muscle cells (VSMCs) are key events in proliferative vascular pathologies such as atherosclerosis and post-angioplastic restenosis. There is no proper cell culture system allowing VSMC differentiation so that it is difficult to delineate the molecular mechanism responsible for proliferative vasculopathy. We investigated whether a micro-patterned substrate could restore the contractile phenotype of VSMCs in vitro. To induce and maintain the differentiated VSMC phenotype in vitro, we introduced a micro-patterned groove substrate to modulate the morphology and function of VSMCs.
Project description:Background: Moyamoya is a cerebrovascular condition of unknown mechanism characterized by a progressive stenosis of the terminal part of the internal carotid arteries (ICA) and the compensatory development of abnormal “moyamoya” vessels. It leads to ischemic and hemorrhagic stroke. We describe a novel autosomal recessive disease leading to severe moyamoya and early onset achalasia and report its cause in 3 unrelated families. Methods: We used a combination of genetic linkage and exome sequencing in 2 consanguineous to identify rare shared variants. Sanger sequencing of GUCY1A3, the sole gene mutated in both families, was then conducted in the third family. Platelets from one of the patients and controls were used to carry out functional studies. Results: Homozygous mutations of GUCY1A3 gene encoding the alpha1 subunit of soluble guanylate cyclase (sGC), the major receptor for Nitric Oxide (NO), were identified in all 3 families. Platelet analysis showed a complete loss of the mutated protein and showed an unexpected stimulatory role of sGC within platelets. Conclusion: The NO/sGC/cGMP pathway is a major pathway controlling vascular smooth muscle (VSMC) relaxation, vascular tone and vascular remodeling. Our data suggest that alterations of this pathway may lead to an abnormal vascular remodeling process in sensitive vascular areas with low blood A total of 17 samples (8 affected and 9 unaffected) were used for this study. Linkage analysis was performed in a single informative consanguine family composed of 2 unaffected parents, 4 affected siblings and 3 unaffected siblings. Two affected samples in two different families were used for the exome sequencing analysis and results were compared to 20 control exomes (in-house exomes from IntegraGen, Evry, France) and 8 HapMap exomes. All samples were used for Sanger Sequencing confirmation.