Urine-derived stem cells differentiate into urothelial cells and smooth muscle cells in vitro / 中国组织工程研究

ABSTRACT

BACKGROUND: Adult stem cells are pluripotent stem cells that exist in differentiated tissues. Urine-derived stem cells are newly discovered adult stem cells. They have attracted increasing attentions in the tissue engineering, due to its advantages of convenient sampling, highly proliferative ability and multidirectional differentiation potential. OBJECTIVE: To investigate the separation and extraction method of urine-derived stem cells and to investigate the feasibility of differentiation into urothelial cells and smooth muscle cells in vitro. METHODS: Urine specimens were collected from healthy adults, and urine-derived stem cells were obtained by isolation and culture in vitro. Cell counting kit-8 assay was used to detect cell proliferation and plot cell growth curve. Cell phenotype was detected by flow cytometry. The differentiation into urothelial and smooth muscle cells was induced by special medium respectively in vitro. The cell differentiation was detected by quantitative PCR, immunohistochemical staining, immunofluorescence cell staining and western blot assay. RESULTS AND CONCLUSION: Urine-derived stem cells were successfully isolated from the urine specimens of healthy adults. Urine-derived stem cells possessed high proliferation rate and the cell growth curve exhibited an S-shape. Urine-derived stem cells exhibited high expression of CD29 (98.11%) and CD90 (95.74%), both of which are mesenchymal stem cell surface markers. After 14 days of induction in vitro, urine-derived stem cells were able to express urothelial cell specific genes Cytokeratin 7, Cytokeratin 20, Uroplakin II and smooth muscle cell specific genes α-SMA and SM22. These results suggest that urine-derived stem cells can differentiate into urothelial cells and smooth muscle cells after induction in vitro and can be used as ideal seed cells for urinary tract tissue engineering.