Effects of Hypoxia with Different Time on Regulations of ERRαBinding to the PDK4 Promoter in Skeletal Muscle of Mice

Objective:Different time hypoxic exposure inducing ERRαbinding to the PDK4promoter and PDK4mRNA expression was investigated, which is to discuss the possible mechanism of carbohydrate metabolism and regulations among signal molecules under hypoxic conditions.Methods:Wild-type C57BL/6Jmice were subjected to either normoxia or hypoxia.Mice in the hypoxia groups were exposed to a hypobaric chamber that replicated the hypobaric hypoxia conditions found at 4 500maltitude for 8hours a day.And then each group with 10mice is also randomly based on the different days (0, 7, 14, 28) .Mice of the normoxic and hypoxic groups in the same days were sacrificed.Performing CHIP assay to confirm the hypoxia treated regulation of ERRαon PDK4promoter.PDK4mRNA was measured by Real Time-PCR.Results:1) When hypoxia exposed for 14days and 28days, ERRαrecruitment on PDK4promoter trends to elevate but has no significance;2) Comparing with 0day groups and normoxia 28 days group, hypoxia 28days group's PDK4mRNA was significantly increased (P<0.05) .Conclusion:Under 28days' exposure of hypoxia, PDK4mRNA was significantly increased in mice skeletal;muscles, but the ERRαrecruitment on PDK4promoter has no significant augment.So, we conjecture ERRαas a compensatory transcription control mechanism to PDK4.