A Study Of Glutathione S Transferase P1in Liver Diseases

Acute-on-chronic liver failure is a serious syndrome characterized by hepatic decompensation with a short onset of jaundice, very high alanine aminotransferase (ALT) level and low prothrombin time activity (PTa) level, which is an acute deterioration of unknown or known chronic liver disease. In China, it often occurs in chronic hepatitis B patients and diagnosed as acute-on-chronic hepatitis B liver failure (ACLF) according to a recent Asia-Pacific consensus recommendation. As a major cause of cancer-related death worldwide, HCC is one of the most frequent human cancers and demonstrates geogrphic variation, particularly in China.GST enzymes play a critical role in the protection against oxidative stress, due to that they can utilize various products of oxidative stress as substrates in liver. The enzyme family is composed of alpha, kappa, mu, omega, pi, sigma, theta, and zeta isoforms in humans,. As a member of the enzyme family, GSTP1is expressed in various normal tissues at different levels and its aberrant activity and expression due to the promoter methylation has been demonstrated in many tumors and other diseases.The present study was designed to evaluate the status of GSTP1promoter methylation, the possible role of GSTP1expression change and redox state in ACLF patients, as well as the potential associations between GSTP1and oxidative stress in HCC patients. 英文摘要第一部分PROMOTER METHYLATION OF OXIDATIVE-STRESS RELATED ENZYME GSTP1AND OXIDATIVE STRESS ANALYSIS IN ACUTE-ON-CHRONIC HEPATITIS B LIVER FAILUREBackground As an antioxidant enzyme, aberrant promoter methylation of Glutathione-S-transferases PI (GSTP1) may be involved in liver damage caused by oxidative stress in acute-on-chronic hepatitis B liver failure(ACLF).Objective To explore GSTP1promoter methylation status and oxidative stress of ACLF patients.Methods DNA was extracted from peripheral blood mononuclear cells (PBMCs) of, chronic hepatitis B (CHB) patients, and normal controls, followed by sodium-bisulfite treatment and methylation-specific PCR (MSP) analysis. Plasma Malondialdehyde (MDA) adduct and was detected by ELISA as oxidative stress marker. Model for end-stage liver disease (MELD) was employed to estimate ACLF severity. GSTP1promoter methylation status of ACLF, chronic hepatitis B (CHB) patients was detected by methylation-specific PCR (MSP-PCR) analysis. GSTP1mRNA expression was detected by quantitative RT-PCR. Oxidant and antioxidant levels were evaluated by plasma Malondialdehyde (MDA) adduct and GSH level detected by ELISA.Results Thirteen of48ACLF and4of48CHB patients displayed GSTP1promoter methylated and the difference was significant (x2=5.79, P=0.03). GSTP1mRNA expression of ACLF patients was significantly decreased compared with CHB patients (P<0.01), and it was significantly decreased in methylated group of ACLF patients than unmethylated group (P=0.01). No considerable difference of clinical parameters were found between methylated and unmethylated group (P>0.05), except total bilirubin (TBIL) level (P=0.04). MDA adduct level was significantly higher in ACLF than CHB patients (12.48±4.8pmol/mg vs8.27±3.4pmol/mg, P=0.03), and GSH level was significantly lower in ACLF patients than CHB patients (0.68±0.3ng/ml versus0.42Q0.18ng/ml, P=0.02). MDA level in methylated ACLF group was higher than in unmethylated group (14.45±6.23pmol/mg versus11.76±3.94pmol/mg, P=0.04), while no significantly different GSH level was found between the two groups (0.46±0.18ng/ml versus0.41±0.18ng/ml, P=0.75). MELD was not significantly different between methylated and unmethylated group of ACLF patients (P>0.05). MDA adduct level is correlated with MELD of ACLF (r=0.579, P<0.01).Conclusion Aberrant GSTP1promoter methylation may facilitate oxidative stress in ACLF, and oxidative stress is correlated with the severity of ACLF. 英文摘要第二部分REDUCED GSTP1EXPRESSION IS DETECTED IN HBV-RELATED HEPATOCELLULAR CARCINOMA PATIENTS COMPARED WITH CHRONIC HEPATITIS B PATIENTS IN CHINABackground Aberrant glutathione-S-transferase PI (GSTP1) expression and increased oxidative stress are involved in various human cancer.Objective We aimed to assay GSTP1expression and oxidative stress status in hepatocellular carcinoma (HCC) patients and chronic hepatitis B (CHB) patients.Methods GSTP1protein expression was detected by flow cytometry in peripheral blood mononuclear cells (PBMC) of38HCC patients,38CHB patients and10 normal contrals, while its mRNA expression level was evaluated by quantitative real-time polymerase chain reaction (QRT-PCR). Enzyme-linked-immunosorbent-assay (ELISA) was employed to measure oxidative stress status indexed with plasma levels of malondialdehyde (MDA), xanthine oxidase (XOD), and reduced glutathione hormone (GSH), glutathione-S-transferases (GST).Results Significantly decreased GSTP1protein expression was found in HCC patients than in CHB patients. GSTP1mRNA expression in HCC patients was also decreased in contrast to CHB patients (P=0.01). Plasma MDA and XOD levels were significantly higher in HCC patients than in CHB patients, while plasma GSH and GST levels were statistically lower in HCC patients than in CHB patients.Conclusion Reduced GSTPl expression is found in PBMC of HCC patients by flow cytometry and contributes to oxidant/antioxidant imbalance in development of HBV-related HCC from CHB in China.