ABSTRACT
ObjectiveTo explore the mechanism of Huangqisan （HQS） in regulating autophagy to alleviate hepatic steatosis and improve non-alcoholic fatty liver disease （NAFLD） based on adenosine 5'-monophosphate-activated protein kinase （AMPK）/mammalian target of rapamycin （mTOR） signaling pathway. MethodThe main chemical components and targets of HQS and NAFLD-related targets were collected from database and the intersection targets were used for Gene Ontology （GO） functional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes （KEGG） pathway enrichment analysis. The protein-protein interaction （PPI） network was constructed， and in vivo experimental verification was conducted. Sixty C57BL/6J male mice were randomly divided into normal control group （NCD）， model group high-fat diet （HFD）， metformin group （MET， 0.25 g·kg-1）， low-dose Huangqisan group （HQS-L， 0.5 g·kg-1）， and the high-dose Huangqisan group （HQS-H， 1 g·kg-1）， with 12 mice in each group after a one-week acclimatization period. NAFLD model was induced by HFD， and intragastric administration was performed at the same time， once a day for 13 weeks. Random blood glucose， serum total cholesterol （TC）， triglyceride （TG）， non-esterified fatty acid （NEFA）， low density lipoprotein-chdesterol （LDL-C） levels， and liver TG content were determined. The liver weight was weighed， and liver index was calculated. Hematoxylin-eosin （HE） staining， oil red O staining， transmission electron microscope （TEM）， real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）， and Western blot were used to verify the effect and reveal the potential mechanism of C57BL/6J mice in vivo. ResultThrough network pharmacology analysis， combined with previous studies， it was predicted that HQS may improve NAFLD by regulating autophagy via the AMPK/mTOR signaling pathway. The result of in vivo experiment showed that， as compared with NCD group， random blood glucose， body weight， serum TC， LDL-C， NEFA， liver weight， liver index， and liver TG content of mice in the HFD groups were significantly increased （P<0.01）. HE staining showed massive lipid droplets （LDs） vacuolated， oil red O staining showed lipid accumulation in liver cells， and no obvious autophagosomes and autolysosome were observed under TEM. The relative mRNA expression of LC3A、LC3B、AMPKα1 and protein expression of AMPK， phosphory phosphorylated（p）-AMPK， and p-AMPK/AMPK were significantly down-regulated （P<0.01）， while the protein expression of microtubule-associated protein 1 light chain 3 （LC3）Ⅱ/Ⅰ and p-mTOR was significantly up-regulated （P<0.01）. As compared with HFD groups， liver weight， serum TG， and NEFA levels in HQS-L and HQS-H groups were significantly deceased （P<0.05， P<0.01）. HE staining and oil red O staining showed the improvement of liver pathological changes after HQS administration. Under TEM， a small amount of autophagosome and autolysosome were observed. Besides， liver index was significantly decreased in the HQS-L group （P<0.01）， and random blood glucose， serum TC level and liver TG content were significantly decreased in the HQS-H group （P<0.05）. The results of Western blot and Real-time PCR showed that the mRNA expression of LC3A and LC3B and the protein expression of LC3Ⅱ/Ⅰ， p-AMPK， and p-AMPK/AMPK were significantly up-regulated （P<0.01）， while the mRNA expressions of p62 and protein expression of p62 and p-mTOR were significantly down-regulated （P<0.05， P<0.01）. ConclusionHQS may promote autophagy and restore autophagy flux via the AMPK/mTOR signaling pathway to alleviate hepatic steatosis improving NAFLD.
ABSTRACT
ObjectiveTo explore the effect and mechanism of Zuogui Jiangtang Tongmai prescription （ZGJTTMP） on astrocytes （ASs） injured by advanced glycation end products（AGEs） combined with oxygen-glucose deprivation （OGD）. MethodCell counting kit-8 （CCK-8） was used to determine the optimal concentration of AGEs and the action time of OGD， and the optimal blood concentration of ZGJTTMP was selected for follow-up experiments. ASs were divided into normal group， model group （AGEs + OGD）， ZGJTTMP group， an adenosine 5'-monophosphate-activated protein kinase （AMPK） inhibitor （Compound C） group， AMPK activator （AICAR） group， and combination group （ZGJTTMP + AICAR）. The morphological changes in ASs in each group were observed under an inverted microscope. The cell survival rate in each group was detected by CCK-8. The content of interleukin-1β（IL-1β）， interleukin-6（IL-6）， and tumor necrosis factor-α（TNF-α） was detected by enzyme-linked immunosorbent assay （ELISA）. The number of autophagosomes in each group was counted under an electron microscope. The expression of microtubule-associated protein light chain 3 （LC3） was observed by immunofluorescence. The protein expression of LC3， p62， p-AMPK， AMPK， p-mammalian target of rapamycin （mTOR）， mTOR， p-UNC-51 like kinase 1 （ULK1）， and ULK1 was detected by Western blot. ResultAccording to the results of cell survival rate， 200 mg·L-1 AGEs and OGD for 6 h were selected as the optimal modeling conditions for the model group， and 5% was selected as the optimal blood concentration of ZGJTTMP. Under the inverted microscope， the cells were severely damaged after modeling， but the cell injury in the ZGJTTMP group and the Compound C group was significantly improved. As revealed by ELISA results， the content of IL-1β， IL-6， and TNF-α in the model group increased （P<0.01）， and the content of inflammatory factors in the ZGJTTMP group and the Compound C group decreased （P<0.01）. Under the electron microscope， the number of autophagosomes in the model group increased significantly. The immunofluorescence results showed that the expression area of LC3 increased in the model group （P<0.01）， and the ZGJTTMP group and the Compound C group showed decreased number of autophagosomes and reduced expression area of LC3 （P<0.01）. As demonstrated by the results of Western blot， compared with the normal group， the model group showed increased expression of LC3Ⅱ/LC3Ⅰ and p-AMPK/AMPK （P<0.01） and decreased p62， p-mTOR/mTOR， and p-ULK1/ULK1 （P<0.01）. Compared with the model group， the ZGJTTMP group and the Compound C group showed decreased expression of LC3Ⅱ/LC3Ⅰ and p-AMPK/AMPK （P<0.01） and increased p62， p-mTOR/mTOR， and p-ULK1/ULK1 （P<0.01）. ConclusionZGJTTMP possesses a protective effect on ASs with inflammatory injury by AGEs combined with OGD， which may be achieved by inhibiting the activation of the AMPK/mTOR/ULK1 pathway related to autophagy， thus inhibiting the overexpression of autophagy.
ABSTRACT
Objective To observe the effect of rosiglitazone on the protein expression of AMPK and GLUT4 in peripheral tissue (liver, skeletal muscle and fat) of type 2 diabetic db/db mice and to prove that rosiglitazone can regulate the glucose metabolism in db/db mice partly through the AMPK pathway. Methods db/db mice were randomly divided into model group and rosiglitazone group according to their blood glucose.The db/m mice were normal control group.After 4 weeks of administration, fasting blood glucose was detected in each group.Western blot was used to detect the contents of AMPK, p-AMPK and GLUT4 in liver, skeletal muscle and adipose tissue. Results (1) Rosiglitazone significantly reduced the fasting blood glucose of db/db mice; (2)Rosiglitazone increased the level of AMPK phosphorylation in the liver, skeletal muscle and adipose tissue of db/db mice, and increased the content of GLUT4 protein in skeletal muscle and adipose tissue. Conclusion Rosiglitazone can increase the phosphorylation of AMPK and the expression of GLUT4 protein in the liver, muscle and fat tissue of db/db mice, and promote the uptake and utilization of glucose in peripheral tissue, suggesting that it can regulate glucose metabolism in db/db mice partly through the AMPK pathway.