Profibrotic effect of miR-33a with Akt activation in hepatic stellate cells.

MicroRNAs (miRNAs) attract more attention in the pathophysiology of liver fibrosis and miR-33a has been previously demonstrated as involved in the regulation of cholesterol and lipid metabolism. Transforming growth factor-beta1 (TGF-ß1) is generally accepted to be the main stimulating factor in the hepatic stellate cells (HSCs) activation, which plays an important role in hepatic fibrosis. However, the involvement and underlying mechanism of miR-33a and its role in TGF-ß1-induced hepatic fibrogenesis remains unknown. Here, we investigate the role of miR-33a in the activation of immortalized human HSCs, Lx-2 cells. Our findings have shown that the expression of miR-33a with its host gene sterol regulatory element-binding protein 2 (SREBP2) was more highly expressed in activation of Lx-2 cells than in quiescent cells. The expression of miR-33a on TGF-ß1-induced HSCs activation may be modulated via the activation of PI3K/Akt pathway. In addition, miR-33a significantly correlated with TGF-ß1-induced expression of α1 (I) collagen (Col1A1) and α-SMA in HSCs. Bioinformatics analyses predict that peroxisome proliferator activated receptor-alpha (PPAR-α) is the potential target of miR-33a. We further found that anti-miR-33a significantly increases target gene PPAR-α mRNA and protein level, suggesting that miR-33a involved in HSCs function might be modulated by targeting PPAR-α. Finally, our results indicate that the expression of miR-33a increased with the progression of liver fibrosis. These results suggested that anti-miR-33a inhibit activation and extracellular matrix production, at least in part, via the activation of PI3K/Akt pathway and PPAR-α and anti sense of miR-33a may be a novel potential therapeutic approach for treating hepatic fibrosis in the future.

Nutrition deficiency increases the risk of stomach cancer mortality.

BACKGROUND: The purpose of the study is to determine whether exposure to malnutrition during early life is associated with increased risk of stomach cancer in later life. METHODS: The design protocol included analyzing the trend of gastric cancer mortality and nutrition and evaluating the association between nutrient deficiency in early life and the risk of gastric cancer by hierarchical age-period-birth cohort (APC) analysis using general log-linear Poisson models and to compare the difference between birth cohorts who were exposed to the 1959-1961 Chinese famine and those who were not exposed to the famine. Data on stomach cancer mortality from 1970 to 2009 and the dietary patterns from 1955 to 1985 which included the 1959-1961 Chinese famine period in the Zhaoyuan County population were obtained. The nutrition information was collected 15 years prior to the mortality data as based on the latest reference of disease incubation. RESULTS: APC analysis revealed that severe nutrition deficiency during early life may increase the risk of stomach cancer. Compared with the 1960-1964 birth cohort, the risk for stomach cancer in all birth cohorts from 1900 to 1959 significantly increased; compared with the 1970-1974 cohort, the risk for stomach cancer in the 1975-1979 cohort significantly increased, whereas the others had a steadily decreased risk; compared with 85-89 age group in the 2005-2009 death survey, the ORs decreased with younger age and reached significant levels for the 50-54 age group after adjusting the confounding factors. The 1930 to 1964 group (exposed to famine) had a higher mortality rate than the 1965 to 1999 group (not exposed to famine). For males, the relative risk (RR) was 2.39 and the 95% confidence interval (CI) was 1.51 to 3.77. For females, RR was 1.64 and 95% CI was 1.02 to 2.62. CONCLUSION: The results of the present study suggested that prolonged malnutrition during early life may increase the risk of stomach cancer mortality in later life.