Metformin ameliorates arsenic trioxide hepatotoxicity via inhibiting mitochondrial complex I.

Arsenic trioxide (ATO) is a well-accepted chemotherapy agent in managing promyelocytic leukemia. ATO often causes severe health hazards such as hepatotoxicity, dermatosis, neurotoxicity, nephrotoxicity and cardiotoxicity. The production of reactive oxygen species, (ROS) play a significant role in ATO-induced hepatotoxicity. The oral hypoglycemic drug, metformin, is considered to be a potential novel agent for chemoprevention in the treatment of cancer. Moreover, metformin has also been shown to have hepatoprotective effects. In the present study, we demonstrated that metformin protected normal hepatocytes from ATO-induced apoptotic cell death in vitro and in vivo. Gene expression screening revealed that glucose metabolism might be related to the metformin-induced protective effect on ATO-treated AML12 cells. The metformin-promoted or induced glycolysis was not responsible for the protection of AML12 cells from ATO-induced apoptotic cell death. Instead, metformin increased the intracellular NADH/NAD+ ratio by inhibiting mitochondrial respiratory chain complex I, further decreasing the intracellular ROS induced by ATO. Treatment with low glucose or rotenone, a mitochondrial respiratory chain complex I inhibitor, also protected AML12 cells from ATO-induced apoptotic cell death. We show for the first time that metformin protects the hepatocyte from ATO by regulating the mitochondrial function. With its properties of chemoprevention, chemosensitization and the amelioration of liver damage, metformin has great prospects for clinical application other than type 2 diabetes mellitus (T2DM).

New-onset diabetes after liver transplantation: a national report from China Liver Transplant Registry.

BACKGROUND/AIMS: New-onset diabetes after transplantation (NODAT) is a serious complication of liver transplantation (LT). The present study aimed to investigate the risk factors of NODAT by a national survey using the China Liver Transplant Registry database. PATIENTS: A total of 10 204 non-pre-existing diabetic patients undergone primary LT between January 2000 and December 2013 were included. Risk factors were identified by logistic regression analysis. RESULTS: NODAT occurred in 24.3% of liver recipients with a median follow-up time of 2.6 years, and was associated with a significantly lower patient survival. NODAT increased not only diabetes related complications (e.g., infection, kidney failure) but also biliary stricture and cholangitis. NODAT patients who received hypoglycaemic treatment had a worse prognosis and a higher hepatocellular carcinoma recurrence compared with those without treatment. New-onset hyperglycaemia (<30 days) was the major predictor of NODAT. Other risk factors included cold ischaemia time >9 h, recipient age >50 years, body mass index >25 kg/m(2) , other hepatitis (mainly hepatitis C), post-transplant intensive care unit stay >15 days, cytomegalovirus infection and corticosteroid at discharge. CONCLUSIONS: The incidence of NODAT in China is similar to that in Western countries. However, the NODAT-related complications are more common and severer in China compared with those in Western countries. The major risk factors are different.

Donor PPARα Gene Polymorphisms Influence the Susceptibility to Glucose and Lipid Disorders in Liver Transplant Recipients: A Strobe-Compliant Observational Study.

Peroxisome proliferator-activated receptor α (PPARα) is an important regulator of glucose and lipid metabolism, and is predominantly expressed in the liver. We aimed to evaluate the effect of donor hepatic PPARα gene polymorphisms on the development of metabolic disorders following liver transplantation (LT).A total of 176 patients undergoing primary LT were included in this Review Board-approved study. Genomic DNA was extracted from fresh frozen donor liver tissues (biopsy specimens for pathological testing at surgery). Eight single nucleotide polymorphisms in the PPARα gene were chosen from either the HapMap CHB database or previous reports.The distribution of metabolic disorders differed significantly between the wild-type and variant genotypes of both the rs5767743 and rs5767700 loci (P < 0.05 for all). After an adjustment for other factors (body mass index and tacrolimus blood concentration), the rs5767743 genetic variant was found to be an independent protective factor (P = 0.005, odds ratio = 0.416 per C allele, 95% confidence interval  = 0.225-0.768). When compared with the wild-type genotype, the variant genotypes rs5767743 and rs5767700 correlated with significantly increased PPARα and CYP3A4 mRNA expression and lower tacrolimus trough concentration/dose ratios (P < 0.05 for all).Donor PPARα gene polymorphisms influence the susceptibility to metabolic disorders following LT and may also be associated with a fasten tacrolimus metabolism because of elevated CYP3A4 expression.