Smoothelin

About: Smoothelin is a research topic. Over the lifetime, 264 publications have been published within this topic receiving 14069 citations.

Novel smooth muscle markers reveal abnormalities of the intestinal musculature in severe colorectal motility disorders.

Abstract: Histopathological studies of gastrointestinal motility disorders have mainly focused on enteric nerves and interstitial cells of Cajal, but rarely considered the enteric musculature. Here we used both classical and novel smooth muscle markers and transmission electron microscopy (TEM) to investigate muscular alterations in severe colorectal motility disorders. Full-thickness specimens from Hirschsprung's disease, idiopathic megacolon, slow-transit constipation and controls were stained with haematoxylin/eosin (HE) and Masson's trichrome (MT), incubated with antibodies against smooth muscle alpha-actin (alpha-SMA), smooth muscle myosin heavy chain (SMMHC), smoothelin (SM) and histone deacetylase 8 (HDAC8) and processed for TEM. Control specimens exhibited homogeneous immunoreactivity for all antibodies. Diseased specimens showed normal smooth muscle morphology by HE and MT. While anti-alpha-SMA staining was generally normal, immunoreactivity for SMMHC, HDAC8 and/or SM was either absent or focally lacking in Hirschsprung's disease (80%), idiopathic megacolon (75%) and slow-transit constipation (70%). Ultrastructurally, clusters of myocytes with noticeably decreased myofilaments were observed in all diseases. SMMHC and the novel smooth muscle markers SM and HDAC8 often display striking abnormalities linked to the smooth muscle contractile apparatus unnoticed by both routine stainings and alpha-SMA, suggesting specific defects of smooth muscle cells involved in the pathogenesis of gastrointestinal motility disorders.

Correction of Diabetic Erectile Dysfunction with Adipose Derived Stem Cells Modified with the Vascular Endothelial Growth Factor Gene in a Rodent Diabetic Model

Abstract: The aim of this study was to determine whether adipose derived stem cells (ADSCs) expressing vascular endothelial growth factor (VEGF) gene can improve endothelial function, recover the impaired VEGF signaling pathway and enhance smooth muscle contents in a rat diabetic erectile dysfunction (DED) model. DED rats were induced via intraperitoneal injection of streptozotocin (40 mg/kg), and then screened by apomorphine (100 µg/kg). Five groups were used (n = 12/group)–Group 1 (G1): intracavernous injection of lentivirus-VEGF; G2: ADSCs injection; G3: VEGF-expressing ADSCs injection; G4: Phosphate buffered saline injection; G1–G4 were DED rats; G5: normal rats. The mean arterial pressure (MAP) and intracavernosal pressure (ICP) were measured at days 7 and 28 after the injections. The components of the VEGF system, endothelial, smooth muscle, pericytes markers in cavernoursal tissue were assessed. On day 28 after injection, the group with intracavernosum injection of ADSCs expressing VEGF displayed more efficiently and significantly raised ICP and ICP/MAP (p<0.01) than those with ADSCs or lentivirus-VEGF injection. Western blot and immunofluorescent analysis demonstrated that improved erectile function by ADSCs-VEGF was associated with increased expression of endothelial markers (VEGF, VEGF R1, VEGF R2, eNOS, CD31 and vWF), smooth muscle markers (a-actin and smoothelin), and pericyte markers (CD146 and NG2). ADSCs expressing VEGF produced a therapeutic effect and restored erectile function in diabetic rats by enhancing VEGF-stimulated endothelial function and increasing the contents of smooth muscle and pericytes.

miR-145 directs intestinal maturation in zebrafish.

Abstract: The rapid specification and differentiation of the embryonic zebrafish gut is essential to provide contractility for the digestion of food. The role of microRNAs in modulating gut epithelial or smooth muscle differentiation is currently not known. Here we show that the microRNA miR-145 is strongly expressed in zebrafish gut smooth muscle and regulates its development. Modulation of miR-145 levels results in gut smooth muscle and epithelium maturation defects. Loss of miR-145 results in defects of smooth muscle function as measured by decreased nitric oxide production but also leads to increased expression of the embryonic smooth muscle markers sm22α-b, nm-mhc-b, and smoothelin. Defects in gut epithelial maturation are also present as observed by immature morphology and a complete loss of alkaline phosphatase expression. Loss or gain of miR-145 function phenocopies defects observed with altered gata6 expression and accordingly, we show that miR-145 directly represses gata6, and that gata6 is a major miR-145 target in vitro and in vivo. miR-145 therefore plays a critical role in promoting the maturation of both layers of the gut during development through regulation of gata6.

Clonal multipotency of skeletal muscle-derived stem cells between mesodermal and ectodermal lineage.

Abstract: The differentiation potential of skeletal muscle-derived stem cells (MDSCs) after in vitro culture and in vivo transplantation has been extensively studied. However, the clonal multipotency of MDSCs has yet to be fully determined. Here, we show that single skeletal muscle-derived CD34-/CD45- (skeletal muscle-derived double negative [Sk-DN]) cells exhibit clonal multipotency that can give rise to myogenic, vasculogenic, and neural cell lineages after in vivo single cell-derived single sphere implantation and in vitro clonal single cell culture. Muscles from green fluorescent protein (GFP) transgenic mice were enzymatically dissociated and sorted based on CD34 and CD45. Sk-DN cells were clone-sorted into a 96-well plate and were cultured in collagen-based medium with basic fibroblast growth factor and epidermal growth factor for 14 days. Individual colony-forming units (CFUs) were then transplanted directly into severely damaged muscle together with 1 x 10(5) competitive carrier Sk-DN cells obtained from wild-type mice muscle expanded for 5 days under the same culture conditions using 35-mm culture dishes. Four weeks after transplantation, implanted GFP+ cells demonstrated differentiation into endothelial, vascular smooth muscle, skeletal muscle, and neural cell (Schwann cell) lineages. This multipotency was also confirmed by expression of mRNA markers for myogenic (MyoD, myf5), neural (Musashi-1, Nestin, neural cell adhesion molecule-1, peripheral myelin protein-22, Nucleostemin), and vascular (alpha-smooth muscle actin, smoothelin, vascular endothelial-cadherin, tyrosine kinase-endothelial) stem cells by clonal (single-cell derived) single-sphere reverse transcription-polymerase chain reaction. Approximately 70% of clonal CFUs exhibited expression of all three cell lineages. These findings support the notion that Sk-DN cells are a useful tool for damaged muscle-related tissue reconstitution by synchronized vasculogenesis, myogenesis, and neurogenesis.