The Relationship Between Mitochondrial Fusion/fission and Apoptosis in the Process of Adipose-derived Stromal Cells Differentiation into Astrocytes

To research the features of mitochondrial fusion and fission proteins and their relationship with apoptosis in the process of adipose-derived stromal cells (ADSCs) differentiation into astrocytes. Immunocytochemistry and Western-blotting were used to analyze the expression of glial fibrillary acidic protein (GFAP), mitochondria fusion-2 (Mfn2), mitochondrial fission-1 (Fis1) and cysteine aspartate specific protease-3 (Caspase-3). Flow cytometry for quantification of the number of apoptotic cells. Transmission electron microscopy (TEM) for observation of the ultrastructure. After induced for 48h, 7, 14 and 21 days showed expression of GFAP, reached the peak on the 7th day (P<0.05). The expression of Mfn2 was decreased with the induction time extending, reached the minimum on the 14th day (P<0.05). The expression of Fis1 and Caspase-3 was increased with the induction time extending, reached the peak on the 14th day (P<0.05, respectively). The rates of early apoptosis, late apoptosis or necrosis were increased gradually (P<0.05). Our findings suggest that in the process of ADSCs differentiation into astrocytes, mitochondrial fusion decreased while mitochondrial fission enhanced significantly; caspase-dependent apoptosis was one of the main reasons leading to cell death.