Effects Of Aerobic Exercise On Pyroptosis-Related Proteins And Inflammatory Factors In Hippocampus Of Mice With Insulin Resistance

Objective: As a new programmed death method,pyroptosis is fundamentally different from apoptosis and necrosis.It depends on activation of inflammasome,recruitment of downstream pro-Caspase-1 / Caspase-1,and cleavage of execution protein of pyroptosis GSDMD and release of inflammatory factors IL-1?,IL-18.Many symptoms such as intensified inflammatory response and excess energy when insulin resistance(IR)occurs are important inducers of pyroptosis.A large number of studies have shown that aerobic exercise has extremely significant effects on many metabolic diseases including insulin resistance,such as reducing inflammation and improving blood lipids and blood glucose levels.Then,in this study,a 12-week high-fat diet was used to establish insulin-resistant mice and a 12-week progressive speed treadmill training model to observe the expression of pyroptosis-and inflammation-related proteins in mouse hippocampus cells after high-fat diet and aerobic intervention.To explore the possible mechanisms by which exercise improves insulin resistance.Methods: Thirty-eight C57 BL / 6J male mice at 6 weeks of age were randomly fed on a normal diet(n = 12)or high-fat diet(HFD,n = 26)for 12 weeks,and the mice were fasted.Blood was collected overnight in the tail vein,and glucose tolerance test(GTT)and insulin tolerance test(ITT)experiments were performed.When the area under curve(AUC)of HFD-fed mice was significantly different from that of normal-fed mice,IR modeling was successful.According to the results,mice were divided into control groups(n = 12)IR group(n = 10)and IR aerobic exercise group(AE,n = 10).The aerobic exercise group performed a 12-week progressive speed treadmill training.After the intervention,fasting for 12 hours,intraperitoneal injection of 10% chloral hydrate(dose 4 ml / kg body weight),anesthesia,sacrifice and strip hippocampal tissues,extract whole tissue protein of hippocampus,determine protein concentration by BCA method and prepare protein samples for Western blot experiments,including gel preparation,sample loading,electrophoresis,transfer membrane,Blocking,incubating the primary antibody overnight,and incubating the secondary antibody for 1 ~ 2 h.Then perform chemiluminescence,development,and image analysis.Finally,the expression of pyroptosis-and inflammation-related proteins was detected.All results were expressed by mean ± SD.Statistical analysis was performed by one-way analysis of variance.Tukey test was used for pairwise comparison.SPSS 24.0 was selected as the data processing software.P <0.05 indicated that the difference was statistically significant.Results: The results showed that compared with control group,nuclear factor-kappa B(NF-?B)(P < 0.01),Nod-like receptor protein 3(NLRP3)(P < 0.05),apoptosisassociated speck-like protein containing CARD(ASC)(P < 0.05),pyroptosis-related proteins like pro-Caspase-1(P < 0.01),gasdermin D(GSDMD)(P < 0.01),GSDMDN(P < 0.05),and inflammatory factors IL-1?(P < 0.05),IL-18(P < 0.05)were significantly increased.The inflammasome-related protein NIMA-related kinase 7(NEK7)and pyroptosis-related protein Caspase-1 showed an increasing trend,but there was no significant difference.Compared with the IR group,progressive speed treadmill training significantly reduced the expression of NF-?B,NLRP3,NEK7,ASC,proCaspase-1,GSDMD,GSDMD-N,IL-1?,and IL-18 in the hippocampus of mice.Conclusion: These results suggested 12-week progressive speed treadmill training can significantly reduce the expression of pyroptosis-related proteins and inflammatory factors in the hippocampus of mice,and inhibit pyroptosis.