ABSTRACT
Objective@#To establish the isolation and culture methods of skeletal muscle stem cells, derived from human orbicularis oculi muscle (OOMSCs), and to identify their multi-directional differentiation potential in vitro.@*Methods@#The cellswere isolated from pretarsal orbicularis oculi muscle (OOM), obtained in routine blepharoplasty surgery.The tissue was digested using collagenase type I combined with re-plating methods. Specific cell surface antigen markers were detected using flow cytometry analysis. OOMSCs were cultured under different inductive conditions, to identify their pluripotent differentiation ability.@*Results@#OOMSCs exhibited similar fibroblast-like morphology as mesenchymal stem cells with high expression of skeletal muscle-derived stem cell surface markers. OOMSCs were able to differentiate into adipocytes, osteoblasts and chondrocytes in vitro, in the presence of lineage-specific inductive media. Moreover, after myogenic induction, the differentiated cells were fused into multinucleated myotube-like structure, and positive for myogenic-related marks, Pax3, Pax7, Myf5 and MyoD.@*Conclusions@#Muscle-derived stem cells can be isolated from human OOM with myogenic differentiation properties, showing further applications potential intissue regeneration and medical therapies of muscle diseases.
ABSTRACT
Adult stem cells from skeletal muscle cells were induced to differentiate into cardiocytes to see if stem cells from another different but histologically-comparable tissues can differentiate to the target cells. Skeletal muscles-derived stem cells (MDSCs) were isolated from adult skeleton muscle tissues by differential adhesion,and immunocytochemically identified by using Sca-1. In order to induce the proliferation but not differentiation of MDSCs,the cells were cultured in Dulbecco's modified Eagle's medium/F12 (DMEM/F12) supplemented with 1:50 B27,20 ng/mL basic fibroblast growth factor (bFGF),20 ng/mL epidermal growth factor (EGF) in a suspension for 6 days. Then these stem cells were treated with 5 μmol/L 5-azacytidine for 24 h in an adherence culture. The characteristics of induced cells were examined by immunocytochemistry,quantitative real time RT-PCR and morphological observation of cell phenotype. Our results showed that the appearance of some cells gradually changed from spindle-shape into polygonal or short-column-shape. Some of these post-treated cells could contract spontaneously and rhythmically. The expression of GATA-4 and cTnT was increased 1 and 2 week(s) after the treatment. And about 16.6% of post-treated cells were cTnT-positive. Therefore,we are led to conclude that skeletal muscle-derived stem cells could differentiate into cardiocyte-like cells,which exhibited some characteristics of cardiocytes.