Effects Of Inhibiting Hedgehog Signaling On Adipogenic Differentiation In Mouse Embryonic Mesenchymal Stem Cells

Intramuscular fat level was one of the crucial factors which had direct effects on pork flavor that low intramuscular fat level might cause variation of pork flavor. There was a negative correlation between intramuscular fat level and lean meat percentage, therefore it was difficult to cope with the problem of this negative correlation by genetic breeding technology sorely. Mediating on adipogenesis of mesenchymal stem cells via hedgehog signaling will be reviewed in this article. The aim is to increase intramuscular fat level and lean meat percentage simultaneously, thus giving comprehensive understanding of porcine breeding and pork quality regulation in china.The Hedgehog signaling pathway is discovered from vertebrates and plays an important role in the processs of embryonic development of many kinds of tissues and organs. Recently, an increased number of researches have demonstrated that Hedgehog signaling pathway regulates adipogenesis. Activation of Hedgehog signaling is known to suppress adipogenesis of mesenchymal stem cells, while it is still unclear whether inhibition of Hedgehog signaling would enhance adipogenesis of mesenchymal stem cells or not. Given this, we focused on the effect of inhibitting of Hedgehog signaling pathway on adipogenesis in stem cells and searched for a method by wnich increase intra-muscular fat content while keep an appropriate lean meat percentage, thus providing the potential applications for the breeding of lean-type pigs and regulation of meat quality.This study was aimed to investigate the effects of Hedgehog signaling on adipogenic differentiation in mesenchymal stem cells and to exploit the potential applications for the breeding of lean-type pigs and regulation of meat quality. [Methods] The mouse multi-potent stem cells-C3H10T1/2 cell line were established. Cells were treated with adipogenic inducer(10 μg/mL insulin, 1 μmol/L dexamethasone, 200 μmol/L indometacin, 0.5 mmol/L IBMX) as a reference control and treated with cyclopamine(5 μmol/L, 10 μmol/L, 15 μmol/L or 20 μmol/L, respectively) for various periods. The relative mRNA expression of genes in Hedgehog signalling, adipogenesis-related transcription regulator genes, or adipogenic gene marker FABP4 was detected using qRT-PCR. The relative level of proteins in Hedgehog signalling, adipogenesis-related transcription regulator, or adipogenic protein marker FABP4 was evaluated by western blot. The adipogenic differentiation was detected with Oil Red O staining in cells.The results showed that cyclopamine reduced the relative mRNA level of genes in Hedgehog signaling but raised the relative mRNA level of PPARγ, C/EBPα and FABP4. Furthermore, Compared with cells treated with medium, the relative mRNA level of genes in Hedgehog signaling was decreased significantly, while the relative mRNA level of PPARγ, C/EBPα and FABP4 was increased significantly in cells treated with 10 μmol/Lol/L cyclopamine(P<0.05); Compared with cells treated with medium, the relative level of proteins in Hedgehog signaling was decreased significantly, while the relative level of PPARγ, C/EBPα and FABP4 was increased significantly in cells treated with 10 μmol/L cyclopamine(P<0.05). The Oil Red O staining showed an obvious induction of adipogenic differentiation in cells. This study demonstrated that cyclopamine exerted promoting effects on the adipogenic differentiation in embryonic mesenchymal stem cells by inhibiting Hedgehog signaling. And the optimal concentration was 10μmol/L.