Based On Lipid Metabolomics, The Mechanism Of Bushen Jianpi Recipe In Improving Abnormal Lipid Deposition In Skeletal Muscle Atrophy Rats

Objective:Using dexamethasone(Dex)combined with the aging rat to produce skeletal muscle atrophy rat model,to observed the relationship between the increase of glucocorticoid induce by Dex and the fat content in skeletal muscle,the expression of lipid metabolism-related gene,to explore the role of glucocorticoid-glucocorticoid receptor signaling pathway in the process of skeletal muscle lipid metabolism disorder induced skeletal muscle atrophy and the intervention of TCM treatment,provides a theoretical basis to enrich the scientific connotation of TCM anti-aging and enhance the clinical application.Methods:1.1Dex induction model:Male SD,3 months old,body mass(200±20)g rats were used to made Dex induction model,which were randomly divided into 5 groups:1)Normal group(Normal):Intraperitoneal injection of saline.2)Model group(Dex):Intraperitoneal injection of Dex.3)Traditional Chinese Medicine group(Dex+Tcm):Intraperitoneal injection of Dex,after giving the herbs.4)Acupuncture group(Dex+Acu):Intraperitoneal injection of Dex,after acupuncture Baihui,Vital and Zusanli,at the same time using electro-acupuncture to stimulates bilateral Zu s anli.5)Antagoni st group(Dex+RU-486):Intraperitoneal injection of Dex,after intraperitoneal injection of glucocorticoid receptor antagonist RU-486.The experiment lasted 14 days,once a day.1.2Natural aging model:Male SD,23 months old,body mass(900±100)g rats were used to made natural aging model,which were randomly divided into 3 groups:1)Old group(Old):Intraperitoneal injection of saline.2)Old Traditional Chinese medicine group(Tcm):Drink the herbs for 5 days a week,and then stop for 2 days.3)Old antagonist group(RU-486):Intraperitoneal injection of normal saline.the glucocorticoid receptor antagonist RU-486 was intraperitoneally injected for one week brfore experiment.Male SD,3 months old,body weight(200±20)g rats were young control group(Young):Intraperitoneal injection of normal saline.The experiment lasted three months,once a day.1.3Biochemical parameters:Gastrocnemius muscle tissue specimens.HE staining was used to observe the changes of muscle fibers in gastrocnemius muscle;Oil-red O staining was used to observe the changes of fat deposition in gastrocnemius muscle;LC/MS technique was used to detect lipids and found differentially expressed lipid metabolites.The expression of GR,SIRT2 and PPARy in the gastrocnemius muscle was detected by Western blotting.The expression of PPARy mRNA in the gastrocnemius muscle was detected by Q-RT PCRResults:1.1Compared with the normal group,the cross-sectional area of the gastrocnemius muscle fibers in the Model group was significantly decreased;the fat droplets in the gastrocnemius muscle tissue were significantly increased,and the fat deposition was obvious.Compared with the Dex group,the thickness of the gastrocnemius muscle fibers in the Normal、Acupuncture、Chinese medicine group and the Antagonist group were significantly improved,the cross-sectional area of the muscle fibers was thickened,the fat droplets in the gastrocnemius muscle tissue were significantly decreased,and the fat deposition was improved.Lipid metabolomics analysis showed that the internal agglomeration of each group of rats was better;the metabolic profile between the groups changed,TG,DG,MG,PC,PE,LPC,LPE and other lipids Metabolite content changes.Molecular level test results:Compared with Dex group,herbs、acupuncture and antagonist can significantly decrease the expression of GR and PPARy protein in the gastrocnemius of rats induced by Dex(P<0.05),and the protein expression of SIRT2 was significantly increased(P<0.05);the relative expression of PPARy mRNA was significantly down-regulated(P<0.05).1.2Compared with the young control group,the cross-sectional area of the gastrocnemius muscle fibers in the aged rats decreased significantly;the fat droplets in the gastrocnemius muscle tissue increased significantly,and the fat deposition phenomenon was obvious.Compared with the old group,the thickness of the gastrocnemius muscle fibers in the old TCM group and the old antagonist group were significantly improved,the cross-sectional area of the muscle fibers was thickened,the fat droplets in the gastrocnemius muscle tissue were significantly decreased,and the fat deposition was improved.Lipid metabolomics analysis showed that the internal agglomeration of each group of rats was better;the metabolic profile between the groups were changed,TG,DG,MG,PC,PE,LPC,LPE and other lipids Metabolite content changes.Molecular detection result:Compared with old group,herbs and antagonists can make the expression of PPARy and GR protein significantly decreased(P<0.05),and the protein expression of SIRT2 was significantly increased(P<0.05);the relative expression of PPARy mRNA was significantly down-regulated(P<0.05)Conclusions:The high corticosterone level in the Dex induction model and the natural aging model can activate GCR pathway down-regulate the expression of histone deacetylase SIRT2 and up-regulate the expression of the key gene PPARγ in the fat synthesis,thereby promoting abnormal deposition of fat in skeletal muscle.The use of RU-486 to block the GCR pathway can correct the abnormal levels of molecular expression,suggesting that the GCR pathway is a key pathway for promoting abnormal deposition of skeletal muscle fat.The Chinese medicine therapy(Chinese medicine/Acupuncture)can regulate the expression level of related molecules by regulating the GCR pathway,thereby improving the skeletal muscle atrophy caused by abnormal fat deposition.