The expression analysis of nanog in the developing rat myocardial tissues.

OBJECTIVES: To investigate the expression dynamic of nanog gene in the development of rat myocardial tissues. METHODS: SD rats were studied at 5 time points before and after birth. The techniques of immunohistochemistry, immunofluorescence, western blotting and RT-PCR were used to investigate the expression of nanog gene in the rat myocardial tissues at different embryonic (E) and postnatal (P) stages, and image analysis system was used for the quantitative analysis. RESULTS: The immunohistochemistry, immunofluorescence and western blotting analyses have shown that expression of nanog protein was highest in the rat myocardial tissues at E18, then it gradually declined at postnatal stages (P<0.05), and became nearly undetectable in most myocardial tissues at P30 with very few remaining nanog-positive cells. RT-PCR result indicated that the expression of nanog gene was strong at E18, but gradually decreased from E18 to P30. CONCLUSION: The mRNA transcription and protein translation of nanog gene in the rat heart gradually decreased with every consecutive growth stage. This indicates that nanog gene has potential regulatory functions in the differentiation of myocardial cells during rat development.

[Expression of ANO1 during cardiac fibroblasts differentiation and its electrophysiological characteristics as calcium-activated chloride channel protein].

OBJECTIVE: To investigate the expression and electrophysiological characteristics of calcium-activated chlorine channel anoctamin-1 (ANO1) protein during the differentiation of cardiac fibroblasts (CFs) into myofibroblasts (MFs), and to elucidate the role of ANO1 in myocardial fibrosis. METHODS: The primary CFs from neonatal rats were isolated and the cells differentiated into MFs by subculture. The Ca2+-activated Cl- current (ICl(Ca)) in CFs and MFs were measured by whole-cell patch clamp, and the expressions of ANO1, α-smooth muscle actin(α-SMA)and vimentin in CFs and MFs were detected by immunofluorescence assay and Western blot, respectively. RESULTS: The current density in the early adherent CFs was stronger than that in MFs. ANO1 was expressed preferentially within and around the nuclei, and a small amount of ANO1 was expressed on the cell membrane. Moreover, ANO1 expression was weak in the early adherent CFs and displayed stronger expression in the MFs with proliferation tendency. CONCLUSION: The expression of ANO1 is closely related to the differentiation of MFs and it may be involved in modulation myocardial fibrosis.

Gata4, Tbx5 and Baf60c induce differentiation of adipose tissue-derived mesenchymal stem cells into beating cardiomyocytes.

The adipose tissue-derived mesenchymal stem cells (ADMSCs) are extensively utilized in tissue engineering, regenerative medicine and cell therapy. ADMSCs can differentiate into cardiomyocytes, and it has been shown that over-expression of a cocktail of factors can induce ectopic heart formation and program cardiogenesis in ESCs. However, which genes are responsible for differentiation of ADMSCs into beating cardiomyocyte-like cells remains unknown. In this study we have shown that the combination of Gata4, Tbx5 and Baf60c is sufficient for inducing ADMSCs to form cardiomyocytes. It also appears that, while Gata4 and Baf60c are key inducers of myocardial differentiation, Tbx5 is essential for the ability of cardiac cells to contract. These findings provide additional experimental references for myocardial tissue engineering in the emerging field of cell-based therapy of heart diseases.