The proliferation and differentiation characteristics of co-cultured porcine preadipocytes and muscle satellite cells in vitro

To explore the proliferation and differentiation characteristics of co-cultured porcine preadipocytes and muscle satellite cells, preadipocytes and muscle satellite cells were isolated from the healthy nascent landrace. Oil Red O stain and desmin immunohistochemistry were used to identify the two solo-cultured cells. Methyl thiazolyl tetrazolium (MTT) colorimetric assay was used to detect the proliferation characteristic of co-cultured cells, and the expression level of differentiation marker genes lipoprotein lipase (LPL), peroxisome proliferator-activated receptors (PPARγ), myogenic factor 5 (Myf5), myogenin (MyoG) were analyzed with reverse transcription PCR (RT-PCR) and western blot. The success of co-culture system was proved. In the co-cultured cells, slight lipid droplets were observed and appeared more slowly. The polykaryocytes fused into myotubes in co-cultured cells were less and relatively slow than that in solo myocytes. After fusion, the proliferation rate of co-cultured cells was higher than that in the solo-cultured muscle satellite cells (P < 0.01), and the duration were also longer. On day 5 and 10, the expression of the marker genes in earlier stage of cell differentiation (LPL and Myf5) were lower than those in the solo-cultured cells (P < 0.01) (except LPL gene at day 5). Moreover, the expression of intermediate and advanced stages’ maker genes (PPARγ2 and MyoG) were hardly detectable at day 5, but increased significantly on day 10 (P < 0.01). These results confirm that the co-culture system could facilitate the cells’ growth and proliferation, meanwhile, inhibited the cell differentiation.