动物造模 Z-bio 2022-12-26 361

　　Objective To screen the differentially expressed genes and their related pathways in tibialis anterior muscle of rats exposed to chronic intermittent hypoxia and acute hypoxia.

　　Methods Twenty four SD rats were divided into normoxia control group (group C) and chronic intermittent hypoxia group (group IH). The oxygen concentration was 12 4%, 8 hours a day for 4 weeks) and acute hypoxia group (AH group, oxygen concentration is 12 4%, 24 hours a day, 3 days in total). After intervention, the grasping force and lean body weight were tested. The tibialis anterior muscle (TA) was taken for HE staining, and then the muscle fiber cross-sectional area (FCSA) was counted. Western Blot method was used to test the relative content of proteins of Atrogin-1 and MuRF1, and the total RNA of rat TA was extracted for sequencing, screening its differential genes, and analyzing the related biological processes (BP) and pathway.

　　Results (1) During the intervention period, the weight of IH group was lower than that of group C, and the weight of AH group continued to decline; After intervention, lean weight and relative grip in AH group were significantly lower than those in C group (P<0 05)。 (2) The morphology of muscle fibers in IH group and AH group was damaged, and it was more obvious in IH group, while the FCSA of TA in each group had no significant difference. (3) The content of Atrogin-1 and MuRF1 in TA in IH group was significantly higher than that in C group, and the content of MuRF1 in AH group was significantly higher than that in C group (P<0 05)。 (4) The screening of differential genes showed that the differential gene that was up-regulated in AH/C group and down-regulated in IH/C group was the slow muscle structure related gene. GO and KEGG analysis showed that IH/C group differential genes were mainly enriched in PPAR pathway; The function of up-regulated differential genes is enriched in the process of antioxidation and glycolipid metabolism, while the down-regulated genes are enriched in the process of transformation and oxidative stress between fast and slow muscles; In AH/C group, the functions of up-regulated differential genes were mainly enriched in oxidative stress, inflammatory reaction and the transformation between fast muscle and slow muscle, while down-regulated genes were enriched in the processes of smad protein signal transduction and ubiquitin protein ligase binding.

　　Conclusion Chronic intermittent hypoxia and acute hypoxia affect the differential expression of tibialis anterior muscle in rats, which are enriched in influencing the level of glucose and lipid metabolism and promoting oxidative stress and inflammatory reaction, respectively, indicating that different hypoxia modes can affect the metabolism of skeletal muscle through different transcription pathways.