Mechanism studies underlying the alleviatory effects of isoliquiritigenin on abnormal glucolipid metabolism triggered by type 2 diabetes / 药学学报

Isoliquiritigenin (ISL) is an active chalcone compound isolated from licorice. It possesses anti-inflammatory and anti-oxidative activities. In our previous study, we uncovered a great potential of ISL in treatment of type 2 diabetes mellitus (T2DM). Therefore, this study aims to reveal the mechanism underlying the alleviatory effects of ISL on T2DM-induced glycolipid metabolism disorder. High-fat-high-sugar diet (HFD) combined with intraperitoneal injection of streptozotocin (STZ) were used to establish T2DM mice model. All animal experiments were carried out with approval of the Committee of Ethics at Beijing University of Chinese Medicine. HepG2 cells were used in in vitro experiments, and sodium palmitate (SP) was applied to establish insulin resistance (IR) model cells. The effects of ISL on body weight, fasting blood glucose levels, and pathological changes in the livers of mice were examined. Enzyme-linked immune sorbent assay (ELISA) and real-time quantitative PCR (RT-qPCR) were applied to detect the regulatory effects of ISL on key targets involved in glucolipid metabolism. Additionally, molecular docking and analytical dynamics simulation methods were used to analyze the interaction between ISL and key target protein. The results indicate that ISL significantly downregulates the transcriptional levels and inhibits the activities of key enzymes involved in gluconeogenesis, including pyruvate carboxylase (PC), phosphoenolpyruvate carboxykinase (PEPCK), and fructose-1, 6-bisphosphatase (FBP). It also downregulates the transcriptional and protein levels of hepatocyte nuclear factor 4α (HNF4α) and cAMP response element binding protein (CREB), the two transcriptional factors involved in gluconeogenesis. Thus, ISL inhibits hepatic gluconeogenesis in T2DM mice. In addition, ISL reduces total cholesterol (TC) and triglyceride (TG) levels in the livers of T2DM mice. Moreover, ISL downregulates the mRNA levels of lipogenesis genes and upregulates those of genes involved in fatty acid oxidation, lipid uptake, and lipid export. In conclusion, ISL suppresses hepatic gluconeogenesis, promotes lipolysis, and restrains lipogenesis in T2DM mice, thereby improving the abnormal glycolipid metabolism caused by T2DM.

Mechanism of Qizhu Kang'ai Prescription for Inhibiting Proliferation of Hepatocellular Carcinoma by Regulating Tumor Metabolic Reprogramming via PCK1/Akt/p21 Signal Axis / 中国实验方剂学杂志

ObjectiveTo study the effect of Qizhu Kang'ai prescription （QZAP） on the gluconeogenesis enzyme phosphoenolpyruvate carboxykinase 1 （PCK1） in the liver of mouse model of liver cancer induced by diethylnitrosamine （DEN） combined with carbon tetrachloride （CCl4） and Huh7 cells of human liver cancer， so as to explore the mechanism on regulating metabolic reprogramming and inhibiting cell proliferation of liver cancer cells. MethodDEN combined with CCl4 was used to construct a mouse model of liver cancer via intraperitoneal injection. A normal group， a model group， and a QZAP group were set up， in which QZAP （3.51 g·kg-1） or an equal volume of normal saline was administered daily by gavage， respectively. Serum and liver samples were collected after eight weeks of intervention. Serum alanine aminotransferase （ALT）， aspartate aminotransferase （AST）， γ-glutamyltransferase （γ-GT）， and alpha-fetoprotein （AFP） in mice were detected to evaluate liver function changes of mice in each group. Hematoxylin-eosin （HE） staining and Sirius red staining were used to observe pathological changes in liver tissue. In the cell experiment， Huh7 cells were divided into blank group， QZAP low， medium， and high dose groups and/or PCK1 inhibitor （SKF-34288 hydrochloride） group， and Sorafenib group. The corresponding drug-containing serum and drug treatment were given， respectively. Cell counting kit-8 （CCK-8） method， colony formation experiment， Edu fluorescent labeling detection， intracellular adenosine triphosphate （ATP） content detection， and cell cycle flow cytometry detection were used to evaluate the proliferation ability， energy metabolism changes， and change in the cell cycle of Huh7 cells in each group. Western blot was used to detect the protein expression levels of PCK1， serine/threonine kinase （Akt）， phosphorylated Akt （p-Akt）， and cell cycle-dependent protein kinase inhibitor 1A （p21）. ResultCompared with the model group， the pathological changes such as cell atypia， necrosis， and collagen fiber deposition in liver cancer tissue of mice in the QZAP group were alleviated， and the number of liver tumors was reduced （P<0.01）. The serum ALT， AST， γ-GT， and AFP levels were reduced （P<0.01）. At the cell level， compared with the blank group， low， medium， and high-dose groups of QZAP-containing serum and the Sorafenib group could significantly reduce the survival rate of Huh7 cells （P<0.01） and the number of positive cells with Edu labeling （P<0.01） and inhibit clonal proliferation ability （P<0.01）. The QZAP groups could also reduce the intracellular ATP content （P<0.05） and increase the distribution ratio of the G0/G1 phase of the cell cycle （P<0.05） in a dose-dependent manner. Compared with the model group and blank group， PCK1 and p21 protein levels of mouse liver cancer tissue and Huh7 cells in the QZAP groups were significantly reduced （P<0.05，P<0.01）， and the p-Akt protein level was significantly increased （P<0.01）. Compared with the blank group， the ATP content and cell survival rate of Huh7 cells in the SKF-34288 hydrochloride group were significantly increased （P<0.05）， but there was no statistical difference in the ratio of Edu-positive cells and the proportion of G0/G1 phase distribution. Compared with the SKF-34288 hydrochloride group， the QZAP combined with the SKF-34288 hydrochloride group significantly reduced the ATP content， cell survival rate， and Edu-positive cell ratio of Huh7 cells （P<0.05） and significantly increased the G0/G1 phase distribution proportion （P<0.05）. ConclusionQZAP may induce the metabolic reprogramming of liver cancer cells by activating PCK1 to promote Akt/p21-mediated tumor suppression， thereby exerting an anti-hepatocellular carcinoma proliferation mechanism.

The coronary heart disease of phlegm-stasis cementation syndrome in mini-swine based on platelet proteomics / 药学学报

Based on the technology of platelet proteomics, the key regulatory proteins and pathogenesis of coronary heart disease with phlegm and blood stasis syndrome were explored and analyzed. Based on the previous laboratory research, the model of coronary heart disease in mini-swine with phlegm-stasis cementation syndrome was duplicated. The model was judged by the changes in blood lipid and myocardial tissue characteristics. Furthermore, the platelet proteins were studied by quantitative proteomics, and the differentially expressed proteins were screened. The critical regulatory proteins and biological pathways of coronary heart disease with phlegm-stasis cementation syndrome were analyzed by bioinformatics. After ten weeks of modeling, the levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), very low density lipoprotein (VLDL-C), triglyceride (TG), creatine kinase (CK) and creatine kinase-MB (CK-MB) in the model group were significantly increased, reflecting the pathological changes such as increased blood lipid, abnormal coagulation function and myocardial ischemia in the model group. In addition, compared with the sham group, there were 26 up-regulated proteins and 8 down-regulated proteins in the platelets of the model group. Combined with bioinformatics analysis, it was found that differential proteins mainly involved in glycolysis/gluconeogenesis, pyruvate metabolism, lipid and atherosclerosis, Ras protein signal transduction. Among them, lactate dehydrogenase B (LDHB), alcohol dehydrogenase 5 (ADH5), neuroblastoma ratsarcoma viral oncogene homolog (NRAS) and Kirsten ratsarcoma viral oncogene homolog (KRAS) play a central role when interacting with other proteins and simultaneously participate in multiple action pathways. The results showed that LDHB, ADH5, NRAS, and KRAS may be the marker proteins in CHD with phlegm-stasis cementation syndrome by regulating glycolysis/gluconeogenesis, pyruvate metabolism, lipid and atherosclerosis, Ras protein signal transduction and other biological processes.

Mechanism of Momordica charantia Extract in Regulating Gluconeogenesis in ZDF Diabetes Rats / 中国实验方剂学杂志

ObjectiveTo observe the effect of Momordica charantia extract （MCE） on the gluconeogenesis signaling pathway in diabetes rats. MethodMale Zucker Diabetic Fatty （ZDF） rats aged 5-6 weeks were randomly divided into a model group and an MCE group （administered MCE at a dose of 0.40 g·kg-1 by gavage）. Additionally， seven healthy male ZDF （fa/+） rats were assigned to the normal group and received administration once daily for six consecutive weeks. During the experiment， the general condition of the rats was observed， and body weight was recorded. Fasting blood glucose and random blood glucose levels were measured in the 1st， 3rd， and 5th weeks. In the 6th week， an oral glucose tolerance test （OGTT） was conducted， and serum levels of triglycerides （TG）， free fatty acid （FFA）， total cholesterol （TC）， aspartate aminotransferase （AST）， and alanine aminotransferase （ALT） were measured. Hematoxylin-eosin （HE） staining was performed to examine liver morphology， periodic acid-Schiff （PAS） staining was used to assess hepatic glycogen storage， and Real-time polymerase chain reaction （PCR） was employed to measure the mRNA expression of phosphoenolpyruvate carboxykinase （PEPCK） and glucose-6-phosphatase （G6Pase） in the liver. Western blot analysis was conducted to measure the phosphorylation level of forkhead box protein O1 （FoxO1） and the protein expression of PEPCK and G6Pase in the liver. ResultCompared with the model group， the MCE group showed significant improvements in body weight， fasting blood glucose， random blood glucose， and glucose tolerance （P<0.05， P<0.01） and reduced serum levels of FFA， TC， and TG （P<0.05， P<0.01）. There were no significant differences in ALT and AST between the two groups. In the MCE group， the HE staining revealed more orderly liver cell arrangement and reduced hepatic steatosis and the PAS staining showed increased hepatic glycogen storage. The protein expression of p-FoxO1 in the liver was significantly elevated （P<0.01）， while there was no significant difference in FoxO1 protein expression. The mRNA and protein expression of PEPCK and G6Pase significantly decreased （P<0.05）. ConclusionMCE exhibits glucose-lowering and lipid-lowering effects， improves glucose tolerance， and enhances hepatic glycogen storage. These effects may be attributed to the upregulation of p-FoxO1， leading to the inhibition of PEPCK and G6Pase expression and the regulation of gluconeogenesis-related processes.

The effects and mechanisms of trimethylamine-N-oxide on insulin sensitivity in insulin target cells / 药学学报

Gut microbial metabolite trimethylamine-N-oxide (TMAO) is associated with type 2 diabetes (T2DM). Decreased insulin sensitivity is a significant etiological factor of T2DM. Adipocytes, myocytes, and hepatocytes are the three major target cells for insulin. This study aims to investigate the effects and mechanisms of TMAO on the insulin sensitivity of these target cells. Research results indicate that in different ages of db/db diabetic mice, plasma TMAO levels were increased. TMAO significantly inhibits the insulin signaling pathways in these three major insulin target cells, reduces glucose uptake in 3T3-L1 adipocytes and L6 myocytes and downregulates genes related to gluconeogenesis in primary mouse hepatocytes. Furthermore, in mice with normal insulin sensitivity, elevating plasma TMAO levels to those seen in db/db mice using a minipump results in impaired glucose tolerance and hyperinsulinemia. All animal experiments were carried out with approval of the Experimental Animal Welfare Ethics Committee of the Institute of Materia Medica (Chinese Academy of Medical Sciences and Peking Union Medical College). Mechanistic studies suggest that TMAO exposure increases the levels of endoplasmic reticulum stress-related proteins in these three major insulin target cells. In summary, TMAO directly attenuates insulin sensitivity in insulin target cells, and its mechanism of action may involve enhancing endoplasmic reticulum stress.

Regulation of gluconeogenesis in liver, kidney and intestine by glucagon / 中国药理学通报

Aim To investigate the regulatory effect of glucagon on gluconeogenesis in liver, kidney and intes¬tine during different fasting periods and the underlying mechanism. Methods The 8-week-old male C57BIV 6J mice were randomly divided into six groups ( n = 6) :control group, control + glucagon group, fasting 18 h group, fasting 18 h + glucagon group, fasting 36 h group, and fasting 36 h + glucagon group. Glucose, triglyceride ( TG) and free fatty acids ( FFAs ) kits were used to detect their serum contents in mouse in-traperitoneal injection of glucagon at different fasting time points. Besides, liver/muscle glycogen assay kit and PAS staining were used to detect the glycogen con¬tents in liver tissue. RT-PCR method was used to observe the effects of glucagon on the gene expressions of peroxisome proliferators-activated receptor y coactivator la (PGC-1α), glucose-6-phosphatase (G6Pase) and phosphoenol pyruvate carboxykinase 1 (PEPCK) in liver, kidney and intestine of mice at different fasting time. Western blot was employed to detect the protein expressions of PGC-1α, G6Pase, PEPCK, phosphoryl-ase protein kinase A ( p-PKA) , protlein kinase A (PKA) , phosphorylase cAMp-response element binding protein (p-CREB) and cAMp-response element binding protein (CREB) in liver, kidney and intestine of mice were. Results (1) Glucagon increased the serum glucose level, reduced serum TG and FFAs levels, and reduced the hepatic glycogen content. (2) Glucagon promoted gluconeogenesis via upregulation of PGC-1α. On the stimulation of glucagon, PGC-1α gene and protein expressions in liver were significantly raised by glucagon when the mice were fasted 18 h and 36 h, while the gene and protein expressions of PGC-1α in kidney were obviously up-regulated by glucagon after fasting 18 h. However, PGC-1α gene and protein expressions in intestine were significantly elevated by glucagon at 36 h after fasting. (3 ) Glucagon induced gene and protein expressions of gluconeogenesis-related enzymes G6Pase and PEPCK in liver, kidney and intestine after fasting. (4 ) Glucagon upregulated p-PKA/PKA and p-CREB/CREB in liver. Conclusions Glucagon shows temporal difference in the gluconeo-genic response of liver, kidney and intestine in mice. Glucagon promotes the gene and protein expressions of key gluconeogenic enzymes G6Pase and PEPCK by increasing PGC-1α gene and protein expression, and thus increasing fasting blood glucose. Besides, glucagon promotes hepatic gluconeogenesis via PKA/CREB signaling pathway.

Hepatic retinaldehyde deficiency is involved in diabetes deterioration by enhancing PCK1- and G6PC-mediated gluconeogenesis

Type 2 diabetes (T2D) is often accompanied with an induction of retinaldehyde dehydrogenase 1 (RALDH1 or ALDH1A1) expression and a consequent decrease in hepatic retinaldehyde (Rald) levels. However, the role of hepatic Rald deficiency in T2D progression remains unclear. In this study, we demonstrated that reversing T2D-mediated hepatic Rald deficiency by Rald or citral treatments, or liver-specific Raldh1 silencing substantially lowered fasting glycemia levels, inhibited hepatic glucogenesis, and downregulated phosphoenolpyruvate carboxykinase 1 (PCK1) and glucose-6-phosphatase (G6PC) expression in diabetic db/db mice. Fasting glycemia and Pck1/G6pc mRNA expression levels were strongly negatively correlated with hepatic Rald levels, indicating the involvement of hepatic Rald depletion in T2D deterioration. A similar result that liver-specific Raldh1 silencing improved glucose metabolism was also observed in high-fat diet-fed mice. In primary human hepatocytes and oleic acid-treated HepG2 cells, Rald or Rald + RALDH1 silencing resulted in decreased glucose production and downregulated PCK1/G6PC mRNA and protein expression. Mechanistically, Rald downregulated direct repeat 1-mediated PCK1 and G6PC expression by antagonizing retinoid X receptor α, as confirmed by luciferase reporter assays and molecular docking. These results highlight the link between hepatic Rald deficiency, glucose dyshomeostasis, and the progression of T2D, whilst also suggesting RALDH1 as a potential therapeutic target for T2D.

Research advances in abnormal gluconeogenesis in hepatocellular carcinoma / 临床肝胆病杂志

Tumors still perform glycolysis in the aerobic environment to accelerate the uptake of glucose and produce a large amount of lactic acid in tumor microenvironment, provide biomolecular precursors of nucleotides, lipids, and proteins for tumor cell proliferation, and inhibit the function of immune cells and promote the metastasis of tumor cells in acidic environment. Gluconeogenesis, as the reverse reaction of glycolysis, is inhibited in hepatocellular carcinoma, especially the downregulated expression of the four key rate-limiting enzymes pyruvate carboxylase, phosphoenolpyruvate carboxykinase, fructose-1, 6-diphosphate 1, and glucose-6-phosphatase 4, which promotes the growth and proliferation of hepatocellular carcinoma by promoting aerobic glycolysis and its branched pathways, and meanwhile, it is also associated with the overall survival time and prognosis of patients with hepatocellular carcinoma and is considered an inhibitor for hepatocellular carcinoma. Therefore, this review summarizes the changes and mechanism of action of the key enzymes of gluconeogenesis in the development and progression of hepatocellular carcinoma and analyzes the shortcomings and future directions of related research in hepatocellular carcinoma, so as to provide new ideas for the treatment of hepatocellular carcinoma.

Study on the mechanism of Poria cocos polysaccharides on the regulation of gluconeogenesis in liver of type 2 diabetic mellitus model rats / 中国药房

OBJECTIVE To investigate the effect and mechanism of Poria cocos polysaccharides on the regulation of blood glucose in type 2 diabetes mellitus （T2DM）model rats by phosphatidylinositol 3-kinase（PI3K）/protein kinase B （Akt）/forked box transcription factor O 1（FoxO1）pathway. METHODS SD rats were randomly divided into blank control group （no modeling ，no administration），model group （modeling，no administration ），metformin group （modeling，200 mg/kg）and P. cocos polysaccharide low-dose，medium-dose and high-dose groups （modeling，100，200，400 mg/kg），8 in each group. Except for blank control group ， other groups were given high fat diet combined with streptozotocin to construct the model of T 2DM rats. At the same time ， administration groups were given relevant dose of medicine intragastrically ，and blank control group and model group were given constant volume of water intragastrically ，once a day ，for consecutive 42 days. During the experiment ，general condition and bodyweight of rats were observed every day ；fasting blood glucose （FBG）of rats were collected ，and oral glucose tolerance test were conducted and area under curve （AUC）was calculated the day before last administration. After last medication ，the heart ，liver， kidney organ index were calculated ；the levels of HbA 1c，TC，TG，MDA，SOD，GSH-Px and hepatic glycogen content were detected. HE staining was used to observe the pathological changes of liver and pancreatic tissue ，and the pathological grade score was calculated. Western blot assay was used to detect the protein expressions of p-PI 3K，p-Akt，p-FoxO1， PEPCK and G 6Pase in liver tissues. RESULTS Compared with blank control group ，the rats of model group suffered cc1965@163.com from polydipsia ，polyphagia and polyuria ；the body weight ， the levels of SOD and GSH-Px ，the protein expressions of p-PI 3K，p-Akt and p-FoxO 1 were significantly decreased （P＜0.05）；liver and kidney organ index ，blood glucose level at 0，0.5 and 2 hours after intragastric administration of glucose solution ，AUC， FBG，HbA1c，serum levels of MDA ，TC，TG and hepatic glycogen content ，liver and pancreatic pathological grade score ，the protein expressions of PEPCK and G 6Pase were all increased significantly （P＜0.05）. Compared with model group ，the general condition of rats in P. cocos polysaccharide groups were all improved ，and all of above indicators had been reversed to varying degrees. CONCLUSIONS P. cocos polysaccharide can downregulate protein expressions of PEPCK and G 6Pase which are key enzymes of gluconeogenesis ，inhibit hepatic gluconeogenesis ，effectively decrease blood glucose levels and regulate glucolipid metabolism in T 2DM model rats by weakening oxidative stress and upregulating PI 3K/Akt/FoxO1 pathway.

FXR agonist GW4064 ameliorates tacrolimus-induced abnormalities in glucose metabolism / 中国临床药理学与治疗学

AIM: To investigate the expression of glucose metabolism genes associated with tacrolimus-induced post-transplant diabetes in the mouse kidney and the mechanisms involved in the regulation of glucose metabolism by farnesylate X (FXR) receptor activator. METHODS: The gene expression levels of FXR, small heterodimeric partner-1 (SHP-1), phosphoenolpyruvate carboxykinase (PEPCK), and glucose transporter protein-2 (GLUT2) were measured after 72 h in HK-2 cell lines treated with tacrolimus and tacrolimus+FXR agonist (GW4064) and control groups, respectively. C57BL/6J male mice were gavaged with tacrolimus and tacrolimus+FXR agonist for 12 weeks, respectively, and the control group was given saline to observe the changes in body weight and blood glucose; after the animals were treated, the gene expression levels of FXR, SHP-1, PEPCK, and GLUT2 were detected, respectively. RESULTS: In cellular experiments, the expression of FXR, SHP-1 and GLUT2 genes was decreased in the tacrolimus-treated group (P< 0.05) and the expression of the PEPCK gene was significantly upregulated compared with the control group (P< 0.05). In animal experiments, compared with the control group, the blood glucose values were significantly increased in the tacrolimus-treated group and significantly decreased in the tacrolimus+FXR agonist combination intervention group (P< 0.05), and the expression of FXR, SHP-1 and GLUT2 genes were upregulated (P< 0.05) and the expression of PEPCK genes was significantly decreased in the mice kidney (P< 0.05).CONCLUSION: FXR agonists can improve tacrolimus-induced abnormal glucose metabolism after transplantation. Therefore, FXR may be a potential new target for the prevention and treatment of post-transplant diabetes.

Effect of Astragaloside Ⅳ in Regulating PI3K/Akt/FoxO1 Pathway and Inhibiting Hepatic Gluconeogenesis in Diabetic Rats / 中国实验方剂学杂志

<b>Objective::To investigate the potential mechanism of astragaloside Ⅳ in protecting liver injury and phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/forkheadbox transcription factor 1 (FoxO1), phosphoenolpyruvate carboxykinase (PEPCK) and glucose 6-phosphatase (G6Pase) protein expressions in type 2 diabetic (T2DM) rats. <b>Method::After 6 weeks of high-sugar and high-fat diet, a model of type 2 diabetes was established through intraperitoneal injection of streptozotocin (STZ, 0.035 g·kg^-1). The rats were randomly divided into normal group, model group, low, medium and high-dose astragaloside Ⅳ groups and metformin group, 0.02, 0.04, 0.08 g·kg^-1·d^-1 astragaloside crude drug and 0.2 g·kg^-1·d^-1 metformin were administered in the low, middle and high-dose astragaloside Ⅳ and metformin groups. After 8 weeks of continuous administration, and 24 hours later after the last gavage, the rats were executed. Serum and liver tissues were collected to detect serum liver biochemical indexes, liver index HDL-C. Hematoxylin-eosin (HE) staining was used to observe the pathological changes of liver tissue. Masson staining was used to observe the degree of liver fibrosis. The changes of glycogen, glycoprotein, or mucopolysaccharide in tissue cells were observed by periodic acid Schiff (PAS) reaction staining. Immunohistochemistry and Western blot analysis were used to detect the expression levels of PI3K/Akt/FoxO1 signaling protein and PEPCK and G6Pase in liver tissues of each group. <b>Result::Compared with normal group, the liver index of the model group increased significantly (<italic>P</italic><0.01), the levels of liver function indicators alanine aminotransferase(ALT), aspartate aminotransferase(AST), TC and TG were significantly increased (<italic>P</italic><0.01), while HDL-C and body weight were significantly reduced (<italic>P</italic><0.01). The results of immunohistochemistry and Western blot showed that the signal of PI3K/Akt/FoxO1 was weakened (<italic>P</italic><0.01), and PEPCK and G6Pase were increased (<italic>P</italic><0.01) in model group. Compared with model group, the contents of ALT, AST, TC and TG in middle and high-dose astragaloside Ⅳ groups were significantly decreased (<italic>P</italic><0.05, <italic>P</italic><0.01), while the body weight was significantly increased (<italic>P</italic><0.05, <italic>P</italic><0.01), the middle and high dose of astragaloside Ⅳ significantly inhibited the levels of FoxO1, PEPCK and G6Pase in liver tissue (<italic>P</italic><0.05, <italic>P</italic>< 0.01), and enhanced the phosphorylation of FoxO1 (<italic>P</italic><0.05, <italic>P</italic><0.01). <b>Conclusion::Astragaloside Ⅳ may inhibit T2DM hepatic gluconeogenesis by regulating PI3K/Akt/FoxO1 signaling pathway, and inhibiting high-fat, high-sugar and low-dose STZ, thereby protecting liver damage in T2DM rats.

Melatonin inhibits endogenous glucose via activation of akt in insulin resistant hepg2 cells / 中国药理学通报

Aim To study the effects of melatonin on glucose output in insulin resistant HepG2 cells and the related mechanism. Methods Insulin resistant HepG2 cells were induced by high glucose and insulin (HGI) (25 mmol • L"1 and 1 (irnol • L"1 respectively) co-culture for 24 h,and then melatonin (10 nmol • L"1) was supplied. The glucose uptake and the gly-cogen content were measured. Levels of protein p-Akt, p-FoxOl as well as p-GSK-30 were evaluated by Western blot. The nuclear export of FoxOl and its intracellular localization were detected by immunofluorescence. Results HGI incubation led to significant decrease in insulin-stimulated glucose uptake and glyco-gen synthesis in HepG2 cells (P < 0. 0( ). However, melatonin reversed these inhibitory effects by increasing glucose uptake and glycogen synthesis significantly (P<0. 01). The results also showed that melatonin not only up-regulated levels of protein p-GSK-3 (3, p-Akt and p-FoxOl but also promoted cytoplasm translocation of FoxOl. Conclusions Melatonin could regulate glycogenesis and gluconeogenesis ih insulin resistant HepG2 cells via Akt/GSK-3(3 and Akt/FoxOl pathway. It thus suppresses the endogenous glucose output and improves the glucose metabolism.

Effect of recombinant adenovirus Ad-mir-22 on glucose uptake in HepG2 cells / 生物工程学报

The recombinant adenoviruses expressing miR-22 (Ad-miR-22) was constructed and the effect of Ad-miR-22 on insulin signal pathway and glucose uptake in HepG2 cells was analyzed. MiR-22 gene was amplified by PCR from human hepatocytes and cloned into the pAdTrack-CMV vector to generate the shuttle plasmid pAdT-22. The positive colonies were confirmed by PCR and sequencing. The resultant shuttle plasmid was linearized with Pme I, followed by co-transformation into competent BJ5183 cells containing an adenoviral backbone plasmid (pAdEasy-1) to create the recombinant plasmid pAd-miR-22. After digested with Pac I, the linearized pAd-miR-22 was transfected into 293A packaging cell line to generate recombinant adenoviruses Ad-miR-22. HepG2 cells were infected with Ad-miR-22 or control Ad-GFP (adenoviruses expressing green fluorescent protein), and then the miR-22 expression levels were analyzed by qPCR. The result shows that adenovirus-mediated overexpression of miR-22 significantly decreased insulin-induced glucose uptake in HepG2 cells. Moreover, overexpression of miR-22 markedly decreased insulin-induced phosphorylation of GSK-3β. miR-22 also increased the mRNA levels of gluconeogenic genes in HepG2 cells. Furthermore, Western blotting results indicate that the protein expression of SIRT1 decreased in Ad-miR-22 infected HepG2 cells as compared with Ad-GFP infected HepG2 cells. In summary, overexpressing of miR-22 significantly increased gluconeogenesis while decreased glucose uptake in HepG2 cells. The effect of miR-22 on glucose metabolism may be mediated by SIRT1.

Outcomes of Metformin on Lipid Profile of Type II Diabetes Mellitus Cases in Tertiary Care Hospital

INTRODUCTION:-Metformin acts mainly at the liver by reducing glucose output and secondarily, by augmenting glucose uptake in the peripheral tissues, primarily muscle. These effects are facilitated by the activation of an upstream kinase, liver kinase B1 (LKB-1), which in turn controls the downstream kinase adenosine monophosphates protein kinase (AMPK). AMPK phosphorylates a transcriptional co-activator, transducer of regulated CREB protein 2, resulting in its inactivation which consequently down regulates transcriptional events that promote synthesis of gluconeogenic enzymes METHODOLOGY:- 200 total numbers of cases were included of diabetic mellitus who received 1500mg/day metformin. The duration of study was one year. RESULT:- In results observed that decrease in fasting blood glucose, total cholesterol, LDL- C and TGs. HDL-C levels were increased significantly after treatment. Conclusion:- Therefore, the findings of the present study concluded that metformin used in diabetic treatment improves lipid profile.

Clinical and genetic studies of two cases of fructose-1,6-bisphosphatase deficiency caused by FBP1 mutations / 中国实用儿科杂志

OBJECTIVE: To analyze the clinical and molecular genetic characteristics of 2 cases of fructose-1,6-bisphosphatase deficiency in the same family to provide evidence for the precise treatment,genetic counseling and prenatal diagnosis.METHODS: Clinical data were collected from 2 patients with hypoglycemia encephalopathy,and molecular genetic analysis was performed using targeted capture next-generation sequencing. RESULTS: The 2 patients were siblings,the male proband was 7 years old,mainly manifested with convulsions after hunger or ingestion of a large amount of fructose,accompanied by ketoacidosis;clinical diagnosis was hypoglycemia encephalopathy,and fructose metabolism abnormalities was suspected. The younger brother was 4 years old,mainly showing hunger and sweating in the morning,stomach ache after eating fruit,and convulsion episode once after hunger. Next-generation sequencing results showed that the siblings had c.333+1＿2 delinsTC and c.490 G>A compound heterozygous mutations in the FBP1 gene,and their parents were carriers with normal phenotype.The c.333+1＿2 delins TCis a novel mutation,c.490 G>A is a reported pathogenic mutation,and the two patients were diagnosed with fructose-1,6-bisphosphatase deficiency genetically. CONCLUSION: For children with unexplained hypoglycemia,convulsions and metabolic acidosis,the fructose-1,6-bisphosphatase deficiency should be considered. Early genetic analysis is helpful to clarify the cause,make precise treatment and improve prognosis.

Pros and cons of insulin administration on liver glucose metabolism in strength-trained healthy mice

Non-diabetic individuals use hormones like insulin to improve muscle strength and performance. However, as insulin also leads the liver and the adipose tissue to an anabolic state, the purpose of this study was to investigate the effects of insulin on liver metabolism in trained non-diabetic Swiss mice. The mice were divided into four groups: sedentary treated with saline (SS) or insulin (SI) and trained treated with saline (TS) or insulin (TI). Training was made in a vertical stair, at 90% of the maximum load, three times per week. Insulin (0.3 U/kg body weight) or saline were given intraperitoneally five times per week. After eight weeks, tissue and blood were collected and in situ liver perfusion with glycerol+lactate or alanine+glutamine (4 mM each) was carried out. The trained animals increased their muscle strength (+100%) and decreased body weight gain (-11%), subcutaneous fat (-42%), mesenteric fat (-45%), and peritoneal adipocyte size (-33%) compared with the sedentary groups. Insulin prevented the adipose effects of training (TI). The gastrocnemius muscle had greater density of muscle fibers (+60%) and less connective tissue in the trained groups. Liver glycogen was increased by insulin (SI +40% and TI +117%), as well as liver basal glucose release (TI +40%). Lactate and pyruvate release were reduced to a half by training. The greater gluconeogenesis from alanine+glutamine induced by training (TS +50%) was reversed by insulin (TI). Insulin administration had no additional effect on muscle strength and reversed some of the lipolytic and gluconeogenic effects of the resistance training. Therefore, insulin administration does not complement training in improving liver glucose metabolism.

Hepatic phosphoenolpyruvate carboxykinase expression after gastric bypass surgery in rats with type 2 diabetes mellitus / 中华内分泌外科杂志

Objective To investigate mRNA expression of hepatic phosphoenolpyruvate carboxykinase (PEPCK) after gastric bypass surgery (GBS) in rats with type 2 diabetes mellitus (T2DM).Methods 36 male Goto-Kakizaki rats,aged 12 weeks,were randomly divided into GBS,sham operation with diet restriction (SO),and sham operation alone(control) groups(n=12 per group).The blood lipid levels and fasting plasma glucose (FPG)levels in rats before and 8 weeks after surgery were measured and compared.The insulin sensitivity index (ISI)was calculated.Real-time polymerase chain reaction (RT-PCR) and Western blot were used to detect the expression of PEPCK mRNA and protein in hepatocytes at 8 weeks after operation.Results 8 weeks after operation,the blood lipid levels [TC(1.25±0.08) mmol/L,TG (0.93±0.10) mmol/L,FFA(0.88±0.12) mmoUL] in GBS group were significantly lower than those before operation [TC (2.31 ±0.52) mmol/L,TG(1.44±0.27) mmol/L,FFA (1.08±0.06) mmol/L] (P＜0.05).The fasting blood glucose levels in GBS decreased from (11.73±0.37) mmol/L to (5.13±0.22) mmol/L (P＜0.05),and ISI in GBS group increased from (-5.78±0.10) to (-4.64±0.15) (P＜0.05).PEPCKmR-NA (3.97±0.30) and protein (1.60±0.31) expression significantly reduced (P＜0.05).Conclusion GBS can reduce blood glucose in T2DM rats while improving glucose tolerance and hyperglycemia,and the mechanism appears to be associated with a decrease of hepatic PEPCK mRNA and protein expression.

Anti-hyperglycemic effects and signaling mechanism of Perilla frutescens sprout extract

BACKGROUND/OBJECTIVES: Perilla frutescens (L.) Britton var. (PF) sprout is a plant of the labiate family. We have previously reported the protective effects of PF sprout extract on cytokine-induced β-cell damage. However, the mechanism of action of the PF sprout extract in type 2 diabetes (T2DM) has not been investigated. The present study was designed to study the effects of PF sprout extract and signaling mechanisms in the T2DM mice model using C57BL/KsJ-db/db (db/db) mice. MATERIALS/METHODS: Male db/db mice were orally administered PF sprout extract (100, 300, and 1,000 mg/kg of body weight) or rosiglitazone (RGZ, positive drug, 1 mg/kg of body weight) for 4 weeks. Signaling mechanisms were analyzed using liver tissues and HepG2 cells. RESULTS: The PF sprout extract (300 and 1,000 mg/kg) significantly reduced the fasting blood glucose, serum insulin, triglyceride and total cholesterol levels in db/db mice. PF sprout extract also significantly improved glucose intolerance and insulin sensitivity, decreased hepatic gluconeogenic protein expression, and ameliorated histological alterations of the pancreas and liver. Levels of phosphorylated AMP-activated protein kinase (AMPK) protein expression also increased in the liver after treatment with the extract. In addition, an increase in the phosphorylation of AMPK and decrease in the phosphoenolpyruvate carboxykinase and glucose 6-phosphatase proteins in HepG2 cells were also observed. CONCLUSIONS: Our results sugges that PF sprout displays beneficial effects in the prevention and treatment of type 2 diabetes via modulation of the AMPK pathway and inhibition of gluconeogenesis in the liver.

A Journey to Understand Glucose Homeostasis: Starting from Rat Glucose Transporter Type 2 Promoter Cloning to Hyperglycemia

My professional journey to understand the glucose homeostasis began in the 1990s, starting from cloning of the promoter region of glucose transporter type 2 (GLUT2) gene that led us to establish research foundation of my group. When I was a graduate student, I simply thought that hyperglycemia, a typical clinical manifestation of type 2 diabetes mellitus (T2DM), could be caused by a defect in the glucose transport system in the body. Thus, if a molecular mechanism controlling glucose transport system could be understood, treatment of T2DM could be possible. In the early 70s, hyperglycemia was thought to develop primarily due to a defect in the muscle and adipose tissue; thus, muscle/adipose tissue type glucose transporter (GLUT4) became a major research interest in the diabetology. However, glucose utilization occurs not only in muscle/adipose tissue but also in liver and brain. Thus, I was interested in the hepatic glucose transport system, where glucose storage and release are the most actively occurring.