Eucommia lignans alleviate the progression of diabetic nephropathy through mediating the AR/Nrf2/HO-1/AMPK axis in vivo and in vitro / 中国天然药物

Lignans derived from Eucommia ulmoides Oliver (Eucommia lignans) inhibit the progression of inflammatory diseases, while their effect on the progression of diabetic nephropathy (DN) remained unclear. This work was designed to assess the function of Eucommia lignans in DN. The major constituents of Eucommia lignans were analyzed by UPLC-Q-TOF-MS/MS. The binding between Eucommia lignans and aldose reductase (AR) was predicted by molecular docking. Eucommia lignans (200, 100, and 50 mg·kg-1) were used in model animals to evaluate their renal function changes. Rat glomerular mesangial cells (HBZY-1) were transfected with sh-AR, sh-AMPK, and oe-AR in the presence of high glucose (HG) or HG combined with Eucommia lignans to evaluate whether Eucommia lignans affected HG-induced cell injury and mitochondrial dysfunction through the AR/Nrf2/HO-1/AMPK axis. Eucommia lignans significantly attenuated the progression of DN in vivo. Eucommia lignans notably reversed HG-induced upregulation of inflammatory cytokines and mitochondrial injury, while downregulating the levels of Cyto c, caspase 9, AR, and NOX4 in HBZY-1 cells. In contrast, HG-induced downregulation of Nrf2, HO-1 and p-AMPKα levels were abolished by Eucommia lignans. Meanwhile, knockdown of AR exerted similar therapeutic effect of Eucommia lignans on DN progression, and AR overexpression reversed the effect of Eucommia lignans. Eucommia lignans alleviated renal injury through the AR/Nrf2/HO-1/AMPK axis. Thus, these findings might provide evidence for the use of Eucommia lignans in treating DN.

Hypoglycemic effect of electroacupuncture at "Tianshu" (ST 25) combined with metformin on rats with type 2 diabetes mellitus based on AMPK / 中国针灸

OBJECTIVE@#To observe the hypoglycemic effect of electroacupuncture (EA) at "Tianshu" (ST 25) combined with metformin on rats with type 2 diabetes mellitus (T2DM) as well as its effect on expression of adenosine monophosphate activated protein kinase (AMPK) in liver and pancreas.@*METHODS@#Thirty-six male SD rats were randomly divided into a blank group (6 rats) and a model establishing group (30 rats). The rats in the model establishing group were fed with high-fat diet and treated with intraperitoneal injection of low-dose streptozotocin (STZ) to establish T2DM model. The rats with successful model establishment were randomly divided into a model group, a control group, a metformin group, an EA group and a combination group, 6 rats in each group. The rats in the EA group were treated with EA at "Tianshu" (ST 25), dense-disperse wave, 2 Hz/15 Hz in frequency and 2 mA in current intensity, 20 min each time. The rats in the metformin group were treated with intragastric administration of metformin (190 mg/kg) dissolved in 0.9% sodium chloride solution (2 mL/kg). The rats in the combination group were treated with EA at "Tianshu" (ST 25) and intragastric administration of metformin. The rats in the control group were treated with intragastric administration of 0.9% sodium chloride solution with the same dose. All the treatments were given once a day for 5 weeks. After the intervention, the body mass and random blood glucose were detected; the serum insulin level was detected by ELISA; the expression of AMPK and phosphorylated adenosine monophosphate activated protein kinase (p-AMPK) in liver and pancreas was detected by Western blot method; the expression of protein gene product 9.5 (PGP9.5) was detected by immunofluorescence.@*RESULTS@#①Compared with the blank group, the body mass in the model group was decreased (P<0.05); compared with the model group, the body mass in the EA group and the combination group was decreased (P<0.05); the body mass in the EA group and the combination group was lower than the metformin group (P<0.05). Compared with the blank group, the random blood glucose in the model group was increased (P<0.01); compared with the model group, the random blood glucose in the metformin group, the EA group and the combination group was decreased (P<0.01). The random blood glucose in the combination group was lower than the metformin group and the EA group (P<0.05). ②Compared with the blank group, the insulin level in the model group was decreased (P<0.05); compared with the model group, the insulin level in the metformin group, the EA group and the combination group was all increased (P<0.05). The insulin level in the combination group was higher than the metformin group and the EA group (P<0.05). ③Compared with the blank group, the protein expression of AMPK and p-AMPK in liver tissue was decreased (P<0.05), and the protein expression of AMPK and p-AMPK in pancreatic tissue was increased (P<0.05) in the model group. Compared with the model group, the protein expression of AMPK and p-AMPK in liver tissue in the metformin group, the EA group and the combination group was increased (P<0.05, P<0.01); the protein expression of AMPK in pancreatic tissue in the metformin group was increased (P<0.05); the protein expression of AMPK in pancreatic tissue in the EA group and the combination group was decreased (P<0.05); the protein expression of p-AMPK in pancreatic tissue in the metformin group, the EA group and the combination group was decreased (P<0.05). The protein expression of AMPK and p-AMPK in liver tissue in the combination group was higher than that in the metformin group and the EA group (P<0.05); the protein expression of AMPK in pancreatic tissue in the EA group and the combination group was less than that in the metformin group (P<0.05), and the expression of p-AMPK protein in pancreatic tissue in the combination group was less than that in the metformin group and the EA group (P<0.05). ④Compared with the blank group, the expression of PGP9.5 in pancreatic tissue in the model group was increased (P<0.01); compared with the model group, the expression of PGP9.5 in pancreatic tissue in the metformin group, the EA group and the combination group was decreased (P<0.05, P<0.01). The expression of PGP9.5 in pancreatic tissue in the EA group was lower than the metformin group and the combination group (P<0.05).@*CONCLUSION@#Electroacupuncture at "Tianshu" (ST 25) could promote the effect of metformin on activating AMPK in liver tissue of T2DM rats, improve the negative effect of metformin on AMPK in pancreatic tissue, and enhance the hypoglycemic effect of metformin. The mechanism may be related to the inhibition of pancreatic intrinsic nervous system.

EGCG and ECG induce apoptosis and decrease autophagy via the AMPK/mTOR and PI3K/AKT/mTOR pathway in human melanoma cells / 中国天然药物

Catechins have been proven to exert antitumor effects in different kinds of cancers. However, the underlying mechanisms have not been completely clarified yet. This study aimed to assess the effects and mechanisms of (-)-epigallocatechin-3-gallate (EGCG) and (-)-epicatechin-3-gallate (ECG) on human melanoma skin A375 cells. Results showed that EGCG and ECG inhibited the proliferation of A375 cells and ECG showed better inhibitory effect. Flow cytometry analysis had shown that EGCG and ECG induced apoptosis and led to cell cycle arrest. EGCG and ECG decreased Bcl-2 expression and upregulated Caspase-3 protein level, indicating the development of apoptosis. Furthermore, EGCG and ECG could decreased mitochondrial membrane potential of A375 cells. In addition, the expression of Beclin-1, LC3 and Sirt3 were downregulated at protein levels, which known to be associated with autophagy. After autophagy was increased by rapamycin, the apoptotic trend was not change, indicating that apoptosis and autophagy are independent. Mechanistically, EGCG and ECG treatments decreased phosphorylated-AMPK (p-AMPK) and increased the ratios of p-PI3K, p-AKT and p-mTOR in melanoma cells. Conclusively, EGCG and ECG induced apoptosis via mitochondrial signaling pathway, downregulated autophagy through modulating the AMPK/mTOR and PI3K/AKT/mTOR signaling pathway. It indicated that EGCG and ECG may be utilized in human melanoma treatment.

β-Elemene induces apoptosis and autophagy in colorectal cancer cells through regulating the ROS/AMPK/mTOR pathway / 中国天然药物

β-Elemene is an effective anti-cancer ingredient extracted from the genus Curcuma (Zingiberaceae familiy). In the present study, we demonstrated that β-elemene inhibited the proliferation of colorectal cancer cells and induced cell cycle arrest in the G2/M phase. In addition, β-elemene induced nuclear chromatin condensation and cell membrane phosphatidylserine eversion, decreased cell mitochondrial membrane potential, and promoted the cleavage of caspase-3, caspase-9 and PARP proteins, indicating apoptosis in colorectal cancer cells. At the same time, β-elemene induced autophagy response, and the treated cells showed autophagic vesicle bilayer membrane structure, which was accompanied by up-regulation of the expression of LC3B and SQSTM1. Furthermore, β-elemene increased ROS levels in colorectal cancer cells, promoted phosphorylation of AMPK protein, and inhibited mTOR protein phosphorylation. In the experiments in vivo, β-elemene inhibited the tumor size and induced apoptosis and autophagy in nude mice. In summary, β-elemene inhibited the occurrence and development of colon cancer xenografts in nude mice, and significantly induced apoptosis and autophagy in colorectal cancer cells in vitro. These effects were associated with regulation of the ROS/AMPK/mTOR signaling. We offered a molecular basis for the development of β-elemene as a promising anti-tumor drug candidate for colorectal cancer.

Rehmanniae Radix and Rehmanniae Radix Praeparata improve diabetes induced by high-fat diet coupled with streptozotocin in mice through AMPK-mediated NF-κB/NLRP3 signaling pathway / 中国中药杂志

This study investigated the differential mechanisms of Rehmanniae Radix and Rehmanniae Radix Praeparata in improving diabetes in mice through AMPK-mediated NF-κB/NLRP3 signaling pathway. The diabetic mouse model was established with high-fat diet coupled with streptozotocin(STZ, intraperitoneal injection, 100 mg·kg~(-1), once a day for three consecutive days), after which the mice were randomly divided into model group, low-dose(5 g·kg~(-1)) and high-dose(15 g·kg~(-1)) Rehmanniae Radix groups, low-dose(5 g·kg~(-1)) and high-dose(15 g·kg~(-1)) Rehmanniae Radix Praeparata groups, catalpol group(250 mg·kg~(-1)), 5-hydroxymethylfurfural(5-HMF) group(250 mg·kg~(-1)), metformin group(250 mg·kg~(-1)), with the normal group also set. The organ indexes of heart,liver, spleen, lung, kidney and pancreas were calculated after four weeks of administration. The pathological changes and fibrosis of pancreas, kidney and liver in mice were observed by hematoxylin-eosin(HE) staining and Masson staining. Western blot was used to determine the expression levels of Toll-like receptor-4(TLR4), nuclear factor-κB(NF-κB), Nod-like receptor protein 3(NLRP3),interleukin-1β(IL-1β), adenosine monophosphate-activated protein kinase(AMPK), phosphorylated AMPK(p-AMPK) in the pancreas, kidney and liver of mice. Compared with the model group, the administration groups witnessed significant decrease in the liver,spleen, kidney, pancreas and fat indexes of diabetic mice, and there was no significant difference in heart and lung indexes. The pathological states and fibrosis of pancreatic, kidney and liver tissues were significantly improved after administration. Additionally, the expression levels of TLR4, NF-κB and NLRP3 in pancreas, kidney and liver of diabetic mice were significantly lowered. The expression levels of p-AMPK/AMPK were enhanced significantly in kidney and liver of mice in Rehmanniae Radix group while in pancreas, kidney and liver in Rehmanniae Radix Praeparata group. This suggests that Rehmanniae Radix and Rehmanniae Radix Praeparata differ in the mechanism of regulating energy metabolism of multiple organs and thereby exerting anti-inflammatory effects to alleviate symptoms of diabetic mice.

The study of copy number variations in the regions of PRKAB2 and PPM1K among congenital heart defects patients

SUMMARY OBJECTIVE: This study was to assess the genetic association of copy number variations in two genes (PRKAB2 and PPM1K) located in two regions (tetralogy of Fallot and ventricular septal defect) in a Chinese Han population. METHODS: A total of 200 congenital heart disease patients (100 tetralogy of Fallot patients and 100 ventricular septal defect patients) and 100 congenital heart defect-free controls were recruited, and quantitative real-time PCR analysis was used to replicate the association of two copy number variations with congenital heart defects in a Chinese Han population. RESULTS: One deletion at PRKAB2 and one duplication at PPM1K were found in two of the tetralogy of Fallot patients, respectively; while all these regions were duplicated in both ventricular septal defect patients and in the 100 congenital heart defects-free controls. CONCLUSIONS: We replicated the copy number variations at the disease-candidate genes of PRKAB2 and PPM1K with tetralogy of Fallot in a Chinese Han population, and in patients with ventricular septal defect mutations in these two genes were not found. These results indicate the same molecular population genetics exist in these two genes with different ethnicity. This shows that these two genes are possibly specific pf tetralogy of Fallot candidates.

RESUMO OBJETIVO: Este estudo teve como objetivo avaliar a associação genética do número de cópias em dois genes (PRKAB2 e PPM1K) localizados em duas regiões (tetralogia de Fallot e comunicação interventricular) em uma população chinesa da etnia Han. METODOLOGIA: Um total de 200 pacientes com doença cardíaca congênita (100 pacientes com tetralogia de Fallot e 100 com comunicação interventricular) e 100 indivíduos livres de defeitos cardíacos congênitos foram recrutados, e uma análise quantitativa de PCR em tempo real foi utilizada para replicar a associação de duas variações de número de cópia de defeitos cardíacos congênitos, em uma população chinesa da etnia Han. RESULTADOS: Uma supressão em PRKAB2 e duplicação em PPM1K foram encontradas em dois pacientes com tetralogia de Fallot, respectivamente; todas essas regiões estavam duplicadas nos pacientes com comunicação interventricular e nos 100 indivíduos livres de defeitos cardíacos congênitos. CONCLUSÃO: Nós replicado a variações no número de cópias de genes candidatos de doença PRKAB2 e PPM1K com tetralogia de Fallot em uma população chinesa da etnia Han; em pacientes com comunicação interventricular, não foram encontradas mutações nesses dois genes. Estes resultados indicam que a mesma genética de população molecular existe nestes dois genes em diferentes etnias. Isso mostra que esses dois genes são possivelmente candidatos a genes específicos de tetralogia de Fallot.

Association of PRKAA1 gene polymorphisms with chronic hepatitis B virus infection in Chinese Han population

ABSTRACT Objective: Studies have indicated that AMPK play critical roles in the regulation of innate immunity and inflammatory responses. However, the role of the polymorphisms of PRKAA1 gene in immune-response to infectious organisms remains unknown. To evaluate the potential role of PRKAA1/AMPKα1 in the immune-response to HBV, we conducted this case-control study. Methods: We recruited 276 patients (145 men and 131 women; average age, 51.6 years) with chronic HBV infection (CHB) and 303 healthy controls (166 men and 137 women; average age, 54.2 years). All the subjects were unrelated individuals of Chinese Han Population. Three SNPs of PRKAA1gene were tested. Results: Rs1002424 polymorphism showed significant difference in the allele frequencies, but no difference in the genotype frequencies (allele: p = 0.039411, OR95%CI = 0.783479 [0.621067-0.988362]; genotype: p = 0.104758); rs13361707 polymorphism showed significance in allele analysis, but not in genotype analysis (allele: p = 0.034749, OR95%CI = 1.284303 [1.017958-1.620335]; genotype: p = 0.098027); rs3792822 polymorphism was demonstrated to have significant differences in both genotype and allele frequencies between cases and controls (allele: p = 0.029286, OR95%CI= 0.741519 [0.566439-0.970716]; genotype: p = 0.034560). The haplotype results showed that CTG and TCA in the rs13361707-rs1002424-rs3792822 block were significantly associated with the happening of HBV (CTG: p = 0.036854, OR95%CI = 1.281 [1.015-1.617]; p = 0.030841, OR95%CI = 0.743 [0.568-0.973]). Conclusion: These findings suggest that PRKAA1 polymorphisms may contribute to the susceptibility of chronic HBV infection in Chinese Han origin.

The effect of 5-aminoimidazole-4-carboxamide-ribonucleoside was mediated by p38 mitogen activated protein kinase signaling pathway in FRO thyroid cancer cells

BACKGROUND/AIMS: 5'-Adenosine monophosphate (AMP)-activated protein kinase (AMPK) is a cellular energy sensor that monitors intracellular AMP/adenosine triphosphate (ATP) ratios and is a key regulator of the proliferation and survival of diverse malignant cell types. In the present study, we investigated the effect of activating AMPK by 5-aminoimidazole-4-carboxamide-ribonucleotide (AICAR) in thyroid cancer cells. METHODS: We used FRO thyroid cancer cells harboring the BRAF(V600E) mutation to examine the effect of AICAR on cell proliferation and cell survival. We also evaluated the involvement of mitogen-activated protein kinase (MAPK) pathways in this effect. RESULTS: We found that AICAR treatment promoted AMPK activation and suppressed cell proliferation and survival by inducing p21 accumulation and activating caspase-3. AICAR significantly induced activation of p38 MAPK, and pretreatment with SB203580, a specific inhibitor of the p38 MAPK pathway, partially but significantly rescued cell survival. Furthermore, small interfering RNA targeting AMPK-alpha1 abolished AICAR-induced activation of p38 MAPK, p21 accumulation, and activation of caspase-3. CONCLUSIONS: Our findings demonstrate that AMPK activation using AICAR inhibited cell proliferation and survival by activating p38 MAPK and proapoptotic molecules in FRO thyroid cancer cells. These results suggest that the AMPK and p38 MAPK signaling pathways may be useful therapeutic targets to treat thyroid cancer.

Chronic ethanol feeding impairs AMPK and MEF2 expression and is associated with GLUT4 decrease in rat myocardium

Chronic and heavy alcohol consumption is one of the causes of heart diseases. However, the effects of ethanol on insulin sensitivity in myocardium has been unclear. To investigate the effects of ethanol on the expression of AMP-activated protein kinase (AMPK), myocyte enhancer factor 2 (MEF2) and glucose transporter 4 (GLUT4), all of which are involved in the regulation of insulin sensitivity, in the myocardium, we performed three parts of experiments in vivo and in vitro. I: Rats were injected with 5-amino-4-imidazolecarboxamide ribonucleotide (AICAR, 0.8 mg.kg(-1)) for 2 h. II: Rats received different dose (0.5, 2.5 or 5 g.kg(-1).d(-1)) of ethanol for 22-week. III: Primary neonatal rat cardiomyocytes were isolated and treated with or without 100 mM ethanol or 1 mM AICAR for 4 h. The cardiac protein and mRNA expression of AMPKalpha subunits, MEF2 and GLUT4 were observed by western-blotting and RT-PCR, respectively. Serum TNFalpha levels were assessed by ELISA. The results showed chronic ethanol exposure induced insulin resistance. Ethanol decreased the mRNA levels of AMPKalpha1 and alpha2, the protein levels of total- and phospho-AMPKalpha in cardiomyocytes. Similarly, ethanol showed inhibitory effects on both the mRNA and protein levels of MEF2A and 2D, and GLUT4 in a dose-response-like fashion. Correlation analysis implied an association between phospho-AMPKalpha and MEF2A or MEF2D, and between the levels of MEF2 protein and GLUT4 transcription. In addition, ethanol elevated serum TNFalpha level. Taken together, chronic ethanol exposure decreases the expression of AMPKalpha and MEF2, and is associated with GLUT4 decline in rat myocardium.