Mitral valve interstitial Tissue: Myxomatous P2 prolapse of the mitral valve vs. Control
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE109744 | GEO | 2018/01/29
REPOSITORIES: GEO
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Project description:For RNA extraction, we obtained peripheral blood mononuclear cells (PBMCs) from 5 patients with mitral valve prolapse (MVP), with or without chordae tendineae rupture, and 5 healthy individuals. High-throughput sequencing was used for RNA-sequencing.
2023-04-18 | GSE229778 | GEO
Project description:Mitral valve interstitial Tissue: Myxomatous P2 prolapse of the mitral valve vs. Control
| PRJNA431911 | ENA
Project description:Mitral valve prolapse (MVP) is a common condition present in 1-3% of the population. There has been evidence that a subset of MVP patients is at higher risk of sudden cardiac death. The arrhythmogenic mechanism is related to fibrotic changes in the papillary muscles caused by the prolapsing valve. ECG features include ST-segment depression, T wave inversion or biphasic T waves in inferior leads, and premature ventricular contractions arising from the papillary muscles and the fascicular system. Echocardiography can identify MVP and mitral annular disjunction, a feature that has significant negative prognostic value in MVP. Cardiac MRI is indicated for identifying fibrosis. Patients with high-risk features should be referred for further evaluation. Catheter ablation and mitral valve repair might reduce the risk of malignant arrhythmia. MVP patients with high-risk features and clinically documented ventricular arrhythmia may also be considered for an ICD.
| S-EPMC9376835 | biostudies-literature
Project description:Rationale: Ischemic mitral regurgitation (IMR) is frequently observed following myocardial infarction (MI) and is associated with higher mortality and poor clinical prognosis if left untreated. Accumulating evidence suggests that mitral valve (MV) leaflets actively remodel post-MI, yet the cellular mechanisms underlying these responses and how this affects tissue function remain largely unknown. Objective: We sought to elucidate MV remodeling post-MI at the tissue, cellular, and transcriptomic levels. Methods and Results: The mechanical behavior of ovine MV leaflets pre-MI and 8 weeks post-MI reveal a significant decrease in radial direction extensibility, which essentially eliminated the mechanical anisotropy typically observed in healthy MVs. Quantitative histology and ultrastructural assessment by transmission electron microscopy revealed altered leaflet composition and architecture at 8 weeks post-MI. Assessment of the MV interstitial cell (MVIC) nuclear aspect ratio, a metric of cellular deformation, revealed that MVICs were on average rounder following MI. RNA sequencing (RNA-seq) indicated that YAP-induced genes were elevated at 4 weeks post-MI and genes related to extracellular matrix organization were some of the most downregulated in sheep with IMR compared to sheep without IMR at 4 weeks post-MI. Additionally, RNA-seq revealed the possible recruitment of immune cells in this remodeling process due to the drastic elevation of CXCL9 and CLEC10A. Conclusions: This multiscale assessment revealed significant mechanical and microstructural changes due to MI. RNA-seq provided a baseline for global gene expression changes in response to MI with and without IMR and suggests YAP-induced mechanotransduction, altered expression of ECM-related genes, and recruitment of immune cells as mechanisms contributing to altered MV biomechanics post-MI. Conclusions: This multiscale assessment revealed significant mechanical and microstructural changes due to MI. RNA-seq provided a baseline for global gene expression changes in response to MI with and without IMR and suggests YAP-induced mechanotransduction, altered expression of ECM-related genes, and recruitment of immune cells as mechanisms contributing to altered MV biomechanics post-MI.
2020-05-06 | GSE139921 | GEO
Project description:Rational: We previously reported evidence of endothelial to mesenchymal transition (EndMT) and fibrosis in mitral valve (MV) leaflets at two to six months post-myocardial infarction (MI) in sheep. The onset of these changes and the mechanism of their instigation are not known. Early modulation of EndMT and fibrosis in MV leaflets may limit the development of ischemic mitral regurgitation (IMR) and heart failure. H Objective: To test the hypothesis that circulating molecules present in plasma within days after MI incite EndMT and fibrotic processes in MV leaflets. Method and Results: Ovine MVs harvested 8-10 days after inferior MI (IMI) showed an increase in MV thickness by histology and onset of EndMT, shown by increased CD31/α-smooth muscle actin (α-SMA)+ cells in post-MI MV leaflets (10.5±6.9%) versus sham (2.6±4%). In vitro, post-MI plasma induced EndMT and pro-fibrotic markers and enhanced migration of primary mitral valve endothelial cells (VECs). In contrast, sham plasma did not, despite the presence of TGFβ2 at levels known to induce EndMT in VECs (2 ng/ml). Analysis of sham versus post-MI plasma using a cytokine array revealed a significant drop in the Wnt signaling antagonist secreted frizzled-related protein 3 (sFRP3) in post-MI plasma compared to sham plasma, which was confirmed by ELISA. Addition of recombinant sFRP3 to post-MI plasma reversed its EndMT-inducing effect on mitral VECs, measured by restored VE-cadherin, reduced α-SMA, and reduced TGFβ1-3 expression. Extracellular signal related kinase 1/2 and SMAD2/3 phosphorylation were increased in mitral VEC by post-MI plasma, and both were blocked by supplementing the post-MI plasma with sFRP3. RNA-seq analysis of mitral VECs exposed to post-MI versus sham plasma for 24 hours showed upregulated forkhead box M1 (FOXM1), a transcription factor previously shown to drive fibrosis. FOXM1 was co-localized with CD31 in MV leaflets obtained from sheep at 8-10 days post-MI, which suggests FOXM1 may be linked to EndMT initiation. Blocking FOXM1 with Siomycin A (Sio A) reduced EndMT and pro-fibrotic transcripts in post-MI plasma treated mitral VECs. Finally, post-MI plasma-induced and TGFβ-induced FOXM1 was downregulated by sFRP3. Conclusions: Reduced sFRP3 in post-MI plasma appears to facilitate the onset of TGFβ-driven EndMT and fibrosis in mitral VECs by increasing the transcription factor FOXM1. Restoring sFRP3 levels and/or inhibiting FOXM1 may provide new strategies to minimize maladaptive changes that occur in the MV due to MI.
2022-01-15 | GSE182696 | GEO
Project description:BackgroundInitial studies have suggested the familial clustering of mitral valve prolapse, but most of them were either community based among unselected individuals or applied non-specific diagnostic criteria. Therefore little is known about the familial distribution of mitral regurgitation in a referral-type population with a more severe mitral valve prolapse phenotype. The objective of this study was to evaluate the presence of familial mitral regurgitation in patients undergoing surgery for mitral valve prolapse, differentiating patients with Barlow's disease, Barlow forme fruste and fibro-elastic deficiency.MethodsA total of 385 patients (62 ± 12 years, 63% men) who underwent surgery for mitral valve prolapse were contacted to assess cardiac family history systematically. Only the documented presence of mitral regurgitation was considered to define 'familial mitral regurgitation'. In the probands, the aetiology of mitral valve prolapse was defined by surgical observations.ResultsA total of 107 (28%) probands were classified as having Barlow's disease, 85 (22%) as Barlow forme fruste and 193 (50%) patients as fibro-elastic deficiency. In total, 51 patients (13%) reported a clear family history for mitral regurgitation; these patients were significantly younger, more often diagnosed with Barlow's disease and also reported more sudden death in their family as compared with 'sporadic mitral regurgitation'. In particular, 'familial mitral regurgitation' was reported in 28 patients with Barlow's disease (26%), 15 patients (8%) with fibro-elastic deficiency and eight (9%) with Barlow forme fruste (P < 0.001).ConclusionsIn a large cohort of patients operated for mitral valve prolapse, the self-reported prevalence of familial mitral regurgitation was 26% in patients with Barlow's disease and still 8% in patients with fibro-elastic deficiency, highlighting the importance of familial anamnesis and echocardiographic screening in all mitral valve prolapse patients.
| S-EPMC7008556 | biostudies-literature
Project description:Mitral valve prolapse (MVP) affects 1 in 40 people and is the most common indication for mitral valve surgery. MVP can cause arrhythmias, heart failure, and sudden cardiac death, and to date, the causes of this disease are poorly understood. We now demonstrate that defects in primary cilia genes and their regulated pathways can cause MVP in familial and sporadic nonsyndromic MVP cases. Our expression studies and genetic ablation experiments confirmed a role for primary cilia in regulating ECM deposition during cardiac development. Loss of primary cilia during development resulted in progressive myxomatous degeneration and profound mitral valve pathology in the adult setting. Analysis of a large family with inherited, autosomal dominant nonsyndromic MVP identified a deleterious missense mutation in a cilia gene, DZIP1 A mouse model harboring this variant confirmed the pathogenicity of this mutation and revealed impaired ciliogenesis during development, which progressed to adult myxomatous valve disease and functional MVP. Relevance of primary cilia in common forms of MVP was tested using pathway enrichment in a large population of patients with MVP and controls from previously generated genome-wide association studies (GWAS), which confirmed the involvement of primary cilia genes in MVP. Together, our studies establish a developmental basis for MVP through altered cilia-dependent regulation of ECM and suggest that defects in primary cilia genes can be causative to disease phenotype in some patients with MVP.
| S-EPMC7331025 | biostudies-literature
Project description:Mitral valve prolapse (MVP) is a common cardiac valve disease that affects nearly 1 in 40 individuals. It can manifest as mitral regurgitation and is the leading indication for mitral valve surgery. Despite a clear heritable component, the genetic aetiology leading to non-syndromic MVP has remained elusive. Four affected individuals from a large multigenerational family segregating non-syndromic MVP underwent capture sequencing of the linked interval on chromosome 11. We report a missense mutation in the DCHS1 gene, the human homologue of the Drosophila cell polarity gene dachsous (ds), that segregates with MVP in the family. Morpholino knockdown of the zebrafish homologue dachsous1b resulted in a cardiac atrioventricular canal defect that could be rescued by wild-type human DCHS1, but not by DCHS1 messenger RNA with the familial mutation. Further genetic studies identified two additional families in which a second deleterious DCHS1 mutation segregates with MVP. Both DCHS1 mutations reduce protein stability as demonstrated in zebrafish, cultured cells and, notably, in mitral valve interstitial cells (MVICs) obtained during mitral valve repair surgery of a proband. Dchs1(+/-) mice had prolapse of thickened mitral leaflets, which could be traced back to developmental errors in valve morphogenesis. DCHS1 deficiency in MVP patient MVICs, as well as in Dchs1(+/-) mouse MVICs, result in altered migration and cellular patterning, supporting these processes as aetiological underpinnings for the disease. Understanding the role of DCHS1 in mitral valve development and MVP pathogenesis holds potential for therapeutic insights for this very common disease.
| S-EPMC4720389 | biostudies-literature
Project description:BackgroundMitral valve thickness is used as a criterion to distinguish the classical from the non-classical form of mitral valve prolapse (MVP). Classical form of MVP has been associated with higher risk of mitral regurgitation (MR) and concomitant complications. We sought to determine the relation of mitral valve morphology and motion to mitral regurgitation severity in patients with MVP.MethodsWe prospectively analyzed transthoracic echocardiograms of 38 consecutive patients with MVP and various degrees of MR. In the parasternal long-axis view, leaflets length, diastolic leaflet thickness, prolapsing depth, billowing area and non-coaptation distance between both leaflets were measured.ResultsTwenty patients (53%) and 18 patients (47%) were identified as having moderate to severe and mild MR respectively (ERO = 45 ± 27 mm² vs. 5 ± 7 mm², p < 0.001). Diastolic leaflet thickness was similar in both groups (5.5 ± 0.9 mm vs. 5.3 ± 1 mm, p = 0.57). On multivariate analysis, the non-coaptation distance (OR 7.9 per 1 mm increase; 95% CI 1.72-37.2) was associated with significant MR. Thick mitral valve leaflet as traditionally reported (? 5 mm) was not associated with significant MR (OR 0.9; 95% CI 0.2-3.4).ConclusionsIn patients with MVP, thick mitral leaflet is not associated with significant MR. Leaflet thickness is probably not as important in risk stratification as previously reported in patients with MVP. Other anatomical and geometrical features of the mitral valve apparatus area appear to be much more closely related to MR severity.
| S-EPMC3296553 | biostudies-literature
Project description:The overall goal of this study is to determine the transcriptomic consequences of the absence of epicardial-derived cells in the parietal leaflets of the atrioventricular valves as a consequence of epicardial deletion of Sox9.
2024-02-14 | GSE236187 | GEO