Expression Of MYH11 Research Articles

Overexpression of Smooth Muscle Myosin Heavy Chain Leads to Activation of the Unfolded Protein Response and Autophagic Turnover of Thick Filament-associated Proteins in Vascular Smooth Muscle Cells

Duplications spanning nine genes at the genomic locus 16p13.1 predispose individuals to acute aortic dissections. The most likely candidate gene in this region leading to the predisposition for dissection is MYH11, which encodes smooth muscle myosin heavy chain (SM-MHC). The effects of increased expression of MYH11 on smooth muscle cell (SMC) phenotypes were explored using mouse aortic SMCs with transgenic overexpression of one isoform of SM-MHC. We found that these cells show increased expression of Myh11 and myosin filament-associated contractile genes at the message level when compared with control SMCs, but not at the protein level due to increased protein degradation. Increased expression of Myh11 resulted in endoplasmic reticulum (ER) stress in SMCs, which led to a paradoxical decrease of protein levels through increased autophagic degradation. An additional consequence of ER stress in SMCs was increased intracellular calcium ion concentration, resulting in increased contractile signaling and contraction. The increased signals for contraction further promote transcription of contractile genes, leading to a feedback loop of metabolic abnormalities in these SMCs. We suggest that overexpression of MYH11 can lead to increased ER stress and autophagy, findings that may be globally implicated in disease processes associated with genomic duplications.

MP47-20 INCREASED RHO-KINASE 2 AND AN INCREASE OF SYNTHETIC SMOOTH MUSCLE-SPECIFIC MARKER EXPRESSION IS OBSERVED IN THE CORPUS CAVERNOSUM OF PATIENTS WITH SEVERE ERECTILE DYSFUNCTION.

You have accessJournal of UrologySexual Function/Dysfunction/Andrology: Basic Research II1 Apr 2014MP47-20 INCREASED RHO-KINASE 2 AND AN INCREASE OF SYNTHETIC SMOOTH MUSCLE-SPECIFIC MARKER EXPRESSION IS OBSERVED IN THE CORPUS CAVERNOSUM OF PATIENTS WITH SEVERE ERECTILE DYSFUNCTION. Maarten Albersen, Trinity Bivalacqua, Johanna Hannan, Loes Linsen, Emmanuel Weyne, Hanna Tinel, Peter Sandner, Pieter Uvin, and Koenraad Van Renterghem Maarten AlbersenMaarten Albersen More articles by this author , Trinity BivalacquaTrinity Bivalacqua More articles by this author , Johanna HannanJohanna Hannan More articles by this author , Loes LinsenLoes Linsen More articles by this author , Emmanuel WeyneEmmanuel Weyne More articles by this author , Hanna TinelHanna Tinel More articles by this author , Peter SandnerPeter Sandner More articles by this author , Pieter UvinPieter Uvin More articles by this author , and Koenraad Van RenterghemKoenraad Van Renterghem More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2014.02.1473AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail Introduction and Objectives Various animal models of erectile dysfunction (ED) have consistently shown upregulation of the RhoA/Rho associated protein kinase (ROCK) pathway, specifically isoform ROCK2, in the corpus cavernosum (CC). In vascular diseases such as hypertension and atherosclerosis, a long-term increased ROCK activation and/or upregulation results in vascular wall fibrosis by inducing a phenotypical switch from contractile smooth muscle cells (SMCs) to synthetic SMCs, also termed myofibroblasts (MFs). This switch in phenotype reflects a continuum, in which various phenotypical states are reflected by the expression of a distinct set of markers. Alpha-SMC actin (aSMA) is expressed in both contractile SMCs as well as in MFs. SMC heavy chain kinase (MYH11)is almost exclusively expressed in contractile SMCs, and is not expressed in MFs. We aimed to see whether phenotypical changes are occurring in the human CC SMCs by examining expression of ROCK mRNA and evaluating the regulation of genes involved in the phenotypical switch of SMCs. Methods Specimen of human CC were harvested from consenting patients undergoing penile prosthesis implantation (n=14 patients) and potent control subjects (n=5 healthy controls, needle biopsy). Tissues of patients were compared to those of healthy controls for the expression of mRNA coding for ROCK1, ROCK2, MYH11 and aSMA by qPCR and normalized to the expression of beta-actin. ROCK and aSMA proteins were further localized using immunofluorescence. Statistical analysis was performed using Student’s t-test or Mann–Whitney test, depending on normality of data. Data are reported as mean±SEM. Results aSMA, was expressed more in CC from ED vs control men (relative expression 504243±15265 vs 385483±25456 P<0.05), while MYH11 was downregulated 6-fold in ED patients (26916±5131 vs 156658±14333 P<0.05). ROCK1 was unchanged (P>0.05), while ROCK2 (7570±3013 vs 2924±432 P<0.05) was significantly upregulated in ED patients. ROCK protein colocalized with aSMA, confirming the presence of this kinase in SMCs and MFs. Conclusions We provide evidence of a dysregulation between aSMA and MYH11 expression in human erectile tissue. A decrease of MYH11 expression is indicative of a loss of SMC contractile phenotype. As ROCK2 was upregulated, we postulate that chronic ROCK inhibition may be a future pharmacological target in humans for preventing ED by interfering with smooth muscle phenotype transition. © 2014FiguresReferencesRelatedDetails Volume 191Issue 4SApril 2014Page: e526 Advertisement Copyright & Permissions© 2014MetricsAuthor Information Maarten Albersen More articles by this author Trinity Bivalacqua More articles by this author Johanna Hannan More articles by this author Loes Linsen More articles by this author Emmanuel Weyne More articles by this author Hanna Tinel More articles by this author Peter Sandner More articles by this author Pieter Uvin More articles by this author Koenraad Van Renterghem More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Abstract 149: Pluripotency Factors Krüppel-Like Factor 4 and Octamer-binding Transcription Factor 4 Alter Indices of Plaque Stability in Long Term Western Diet Fed Mice by Regulating Smooth Muscle Cell Phenotypes

The bulk of life threatening thrombotic events have been associated with disruption of the fibrous cap, an atheroprotective layer of smooth muscle α-actin positive (ACTA2+) cells that form around the plaque, and the presence of a large foam cell-laden necrotic core within the plaque. Despite the overwhelming research demonstrating that ACTA2+ cells are beneficial for plaque stability, and cells positive for macrophage-markers are detrimental, there are major ambiguities regarding the origins of these cells, and their role in lesion stability. To clearly define the contribution of smooth muscle cells (SMCs) within atherosclerotic lesions, we generated SMC specific lineage tracing Apoe-/- mice containing a SM myosin heavy chain ( Myh11 ) tamoxifen-inducible cre-recombinase gene and a floxed STOP ROSA eYFP gene ( Myh11 YFP ApoE-/- mice) thus allowing activation of eYFP exclusively in fully differentiated SMCs before the onset of atherosclerosis and subsequent determination of the fate of these cells and their progeny irrespective of continued expression of MYH11 or other SMC marker genes. Remarkably, our results reveal that 86% of SMCs cannot be identified using traditional SMC markers, such as ACTA2, and 23% of presumed macrophages (LGALS3+ cells) are derived from SMC origins. The last finding was confirmed in human coronary atheromas using the ISH-PLA approach. SMC specific knockout (KO) of the pluripotency factor Klf4 in Myh11 YFP ApoE-/- mice did not alter the frequency of phenotypically modulated (ACTA2-eYFP+) SMCs within atherosclerotic lesions of mice fed a high fat diet for 18 weeks, however, decreased the number of ACTA2-eYFP+ SMCs that expressed LGALS3, and increased several indices of plaque stability, suggesting a detrimental role for KLF4 in SMCs within atherosclerotic lesions. Conversely, SMC specific Oct4 KO resulted in a dramatic reduction in the number of ACTA2-eYFP+ SMCs within the lesion with marked decreases in indices of plaque stability. In summary results show that the majority of SMC-derived cells within advanced atherosclerotic lesions cannot be identified using conventional SMC marker genes, and that phenotypic switching of SMC during atherogenesis is differentially regulated by the pluripotency factors KLF4 and OCT4.

Phenotype and steroidogenic potential of PDGFRα-positive rat neonatal peritubular cells

Platelet-derived growth factor receptor α (PDGFRα)-positive peritubular cells (PTCs) are suggested to be putative stem Leydig cells. At present little is known about their phenotype and steroidogenic potential. We isolated highly purified PDGFRα-positive neonatal PTCs by magnetic cell sorting (MACS) from 8dpp rat testes and characterized them in vitro. We have demonstrated that PDGFRα-positive PTCs have a mixed phenotype. They expressed PTC-specific genes (αSma, Myh11), pluripotency markers (Pou5f1, nestin, Lifr) and genes encoding steroidogenic enzymes. Treatment with the cAMP-analog (Bu)2cAMP for 7days upregulated steroidogenic enzyme gene expression and significantly increased their steroidogenic potential. The main end-point steroid was progesterone due to rapid inactivation of CYP17 and 17βHSD. Long-term culturing of PDGFRα-positive PTCs increased the expression of Myh11, and treatment with (Bu)2cAMP attenuated this process.All together, our findings support the hypothesis that neonatal PDGFRα-positive PTCs are steroidogenic competent progeny of stem Leydig cells (SLCs) which give rise to the adult Leydig cell lineage.

Estrogen-Induced Maldevelopment of the Penis Involves Down-Regulation of Myosin Heavy Chain 11 (MYH11) Expression, a Biomarker for Smooth Muscle Cell Differentiation1

Cavernous smooth muscle cells are essential components in penile erection. In this study, we investigated effects of estrogen exposure on biomarkers for smooth muscle cell differentiation in the penis. Neonatal rats received diethylstilbestrol (DES), with or without the estrogen receptor (ESR) antagonist ICI 182,780 (ICI) or the androgen receptor (AR) agonist dihydrotestosterone (DHT), from Postnatal Days 1 to 6. Tissues were collected at 7, 10, or 21 days of age. The smooth muscle cell biomarker MYH11 was studied in depth because microarray data showed it was significantly down-regulated, along with other biomarkers, in DES treatment. Quantitative real time-PCR and Western blot analyses showed 50%-80% reduction (P ≤ 0.05) in Myh11 expression in DES-treated rats compared to that in controls; and ICI and DHT coadministration mitigated the decrease. Temporally, from 7 to 21 days of age, Myh11 expression was onefold increased (P ≥ 0.05) in DES-treated rats versus threefold increased (P ≤ 0.001) in controls, implying the long-lasting inhibitory effect of DES on smooth muscle cell differentiation. Immunohistochemical localization of smooth muscle alpha actin, another biomarker for smooth muscle cell differentiation, showed fewer cavernous smooth muscle cells in DES-treated animals than in controls. Additionally, DES treatment significantly up-regulated Esr1 mRNA expression and suppressed the neonatal testosterone surge by 90%, which was mitigated by ICI coadministration but not by DHT coadministration. Collectively, results provided evidence that DES treatment in neonatal rats inhibited cavernous smooth muscle cell differentiation, as shown by down-regulation of MYH11 expression at the mRNA and protein levels and by reduced immunohistochemical staining of smooth muscle alpha actin. Both the ESR and the AR pathways probably mediate this effect.

Identification of gene expression of MYH11 and PF4V1 in cumulus cells (CC) after ovarian stimulation by microarrays technology: possible implications on oocyte maturation

MYH11 and PF4V1 are genes encoding for molecules related to the regulation of angiotensin II (AngII) and angiogenesis, MYH11 induces the synthesis of AngII and PF4V1 inhibits it. An endothelin-angiotensin-atrial natriuretic peptide functional system at the ovarian level is involved in oocyte maturation and ovulation and seems to be controlled by LH. Since most of the protocols used in IVF require the use of gonadotrophins is logical to think on the possible effect of ovarian stimulation on the process related to ovulation and oocyte maturation.

Recurrent Chromosome 16p13.1 Duplications Are a Risk Factor for Aortic Dissections

Chromosomal deletions or reciprocal duplications of the 16p13.1 region have been implicated in a variety of neuropsychiatric disorders such as autism, schizophrenia, epilepsies, and attention-deficit hyperactivity disorder (ADHD). In this study, we investigated the association of recurrent genomic copy number variants (CNVs) with thoracic aortic aneurysms and dissections (TAAD). By using SNP arrays to screen and comparative genomic hybridization microarrays to validate, we identified 16p13.1 duplications in 8 out of 765 patients of European descent with adult-onset TAAD compared with 4 of 4,569 controls matched for ethnicity (P = 5.0×10−5, OR = 12.2). The findings were replicated in an independent cohort of 467 patients of European descent with TAAD (P = 0.005, OR = 14.7). Patients with 16p13.1 duplications were more likely to harbor a second rare CNV (P = 0.012) and to present with aortic dissections (P = 0.010) than patients without duplications. Duplications of 16p13.1 were identified in 2 of 130 patients with familial TAAD, but the duplications did not segregate with TAAD in the families. MYH11, a gene known to predispose to TAAD, lies in the duplicated region of 16p13.1, and increased MYH11 expression was found in aortic tissues from TAAD patients with 16p13.1 duplications compared with control aortas. These data suggest chromosome 16p13.1 duplications confer a risk for TAAD in addition to the established risk for neuropsychiatric disorders. It also indicates that recurrent CNVs may predispose to disorders involving more than one organ system, an observation critical to the understanding of the role of recurrent CNVs in human disease and a finding that may be common to other recurrent CNVs involving multiple genes.