The Effects of Different Modes of Exercise on PGC-1α/FNDC5/PPARγ Signaling Pathway in Skeletal Muscle of Obese Rats

Objective: To explore the effects of resistance exercise, aerobic exercise or resistance+aerobic exercise on PGC-1α/FNDC5/PPARγ signaling pathway in skeletal muscle of obese rats and its mechanisms in exercise regulating body weight. Methods: Diet-induced obese SD rats were randomly divided into obesity control group (OC group) , obesity aerobic exercise group (OAE group) , obesity resistance exercise group (ORE group) and obesity resistance+aerobic exercise group (OARE group) , 8 rats in each group. The aerobic exercise was performed by running on an animal treadmill, the maximum speed was 20 m/min. The resistance exercise was performed by using a load climbing ladder, after one-week adaptive training, the initial load was set as 20% of the rats' weight, the load was gradually increased to the maximum of 100% of the rats' weight. The resistance exercise was trained every two days for 12 weeks. In OARE group, the aerobic and resistance exercise were conducted alternately, and the intensity was the same as those in OAE and ORE groups. The mR NA and protein expression levels of PGC-1α, FNDC5 and PPARγ were detected by qRTPCR and Western Blotting. Results: 1) After exercise training, the body weight of 3 exercise groups were significantly lower than the OC group (P<0.05) , and the OAE and OARE groups were significantly lower than the ORE group (P<0.05) ; 2) The body fat percentage of the OAE group was significantly lower than that of the OC group (P<0.05) , the body fat percentage of the ORE and OARE groups were lower than that of the OC group but higher than the OAE group with no significant difference (P>0.05) ; 3) The relative expression levels of PGC-1α, FNDC5 and PPARγ mRNA and protein in the ORE, OAE, OARE groups were significantly higher than that of the OC group (P<0.05) ; the relative expression levels of PGC-1α, FNDC5 and PPARγ mRNA and protein in the OAE group were significantly higher than the ORE and OARE groups (P<0.05) ; the relative expression levels of PGC-1α, FNDC5, and PPARγ mR NA and protein in the ORE group were significantly higher than the OARE group (P<0.05) ; 4) The relative expression levels of PGC-1α, FNDC5, and PPARγ mRNA and protein in the gastrocnemius of rats were negatively correlated with the body weight, body fat weight and body fat percentage (P<0.05, P<0.01) . Conclusion: The aerobic exercise, resistance exercise, or resistance+aerobic exercise was effectively in increasing the gene and protein expression levels of PGC-1α, FNDC5, and PPARγ, which promoted the “browning” of white fat tissue and reduced body fat. The effects of resistance exercise or resistance+aerobic exercise on the PGC-1α/FNDC5/PPARγ signaling pathway was not as effective as that of aerobic exercise, however, these two exercise types were revealed a better effect on reducing body fat in terms of time, and the exercise intensity may be the key factor leading to this phenomenon.