BACKGROUND:Bone marrow mesenchymal stem cells (BMSCs) have been induced to differentiate into cardiomyocyte-like cells in vitro.OBJECTIVE:To explore the association between GATA-4, Nkx-2.5 and α-myosin heavy chain (α-MHC) expression and cell morphological changes and structure formation in the process of BMSCs differentiation into cardiomyocyte-like cells.METHODS:By using myocardial lysate, BMSCs were induced to differentiate into cardiomyocytes.Immunocytochemistry staining was used to detect cardiac troponin T (cTnT) and connexin43, for the identification of cardiomyocytes. In the process of directional differentiation, RT-PCR was used to detect the expression of GATA-4,Nkx2.5 and α-MHC.RESULTS AND CONCLUSION:During the directional differentiation of BMSCs, the cells were changed from long fusiform to short rod, forming protrusions that were interconnected to form mesh-like, bamboo-like or myotube-like structure. When the cells were interconnected like a bamboo, cTNT and connexin43 positive cells were visible, and then the number of positive cells increased with the presence of myotube-like structure. RT-PCR results showed that during the induced directional differentiation of BMSCs, GATA-4, Nkx2.5 and α-MHC mRNA levels increased continuously. When interconnected cells formed a mesh-like structure, GATA-4 expression reached the peak and then kept a high level. When adjacent cells were fused into a myotube-like structure, α-MHC reached the peak. Additionally, the expression of Nkx2.5presented a time-dependent increase trend. Overall, during the induced differentiation of BMSCs into cardiomyocyte-like cells, the expression of cardiomyocyte specific genes, characterized by temporality and spatiality, is related to the changes of cell morphology and special structure formation.

BACKGROUND: Bone marrow mesenchymal stem cells have been induced into islet-like cell mass in vitro. However, little researches reported on the morphological changes of cells, the types of endocrine cells in the islet-like cell mass and their relationships. OBJECTIVE: To investigate the morphological changes of cells in the differentiation of bone marrow mesenchymal stem cells into islet-like structure and to explore the composition and distribution of endocrine cells. METHODS: Passage 3 bone marrow mesenchymal stem cells growing well were cultured and expanded until the cell colonies occupies 80% of the bottom of the culture bottle, and the pancreatic tissue lysate was added for continuous induction. Dithizone staining was used to screen the islet-like cell mass directly differentiated from bone marrow mesenchymal stem cells. The types and distribution of endocrine cells were identified by Mallory staining. Expressions of insulin, C-peptide, glucagon and somatostatin protein were detected by immunofluorescence cytochemical staining. RESULTS AND CONCLUSION: (1) Dithizone staining showed that the number of positive cells was increased over the induction time. (2) Mallory staining showed the red α-like cells were located in the periphery of the islet-like cell mass, the yellow β-like cells located in the center and periphery, and the light blue fibroblasts were distributed around the cell mass. (3) Immunofluorescence staining showed insulin, C-peptide, glucagon and somatostatin positive cells in the islet-like cell mass. To conclude, under certain microenvironment, bone marrow mesenchymal stem cells can differentiate into islet-like structures which containing α, β, δ-like cells, and are surrounded by fibroblast-like cells.

"Belt and Road" is an opportunity for the development of traditional Chinese medicine (TCM) education.Based on the analysis of international development of TCM education,this paper focused on how to seize the "Belt and Road" strategic development opportunities to further promote the strategy analysis on international development of TCM education,and put forward specific implementation measures.