Transcriptional regulation of Glis2 in hepatic fibrosis.

The role of Gli-similar 2 (Glis2) in hepatic fibrosis (HF) is controversial. In this study, we focused on the functional and molecular mechanisms involved in the Glis2-mediated activation of hepatic stellate cells (HSCs)-a milestone event leading to HF. The expression levels of Glis2 mRNA and protein were significantly decreased in the liver tissues of patients with severe HF and in mouse fibrotic liver tissues as well as HSCs activated by TGFß1. Functional studies indicated that upregulated Glis2 significantly inhibited HSC activation and alleviated BDL-induced HF in mice. Downregulation of Glis2 was found to correlate significantly with DNA methylation of the Glis2 promoter mediated by methyltransferase 1 (DNMT1), which restricted the binding of hepatic nuclear factor 1-α (HNF1-α), a liver-specific transcription factor, to Glis2 promoters. In addition, the enrichment of DNMT1 in the Glis2 promoter region was mediated by metastasis-associated lung adenocarcinoma transcriptor-1 (MALAT1) lncRNA, leading to transcriptional silencing of Glis2 and activation of HSCs. In conclusion, our findings reveal that the upregulation of Glis2 can maintain the resting state of HSCs. The decreased expression of Glis2 under pathological conditions may lead to the occurrence and development of HF with the expression silencing of DNA methylation mediated by MALAT1 and DNMT1.

11ß­hydroxysteroid dehydrogenase­1 is associated with the activation of hepatic stellate cells in the development of hepatic fibrosis.

Hepatic fibrosis (HF) is a common complication of numerous chronic liver diseases, but predominantly results from persistent liver inflammation or injury. If left untreated, HF can progress and develop into liver cirrhosis and even hepatocellular carcinoma. However, the underlying molecular mechanisms of HF remain unknown. The present study aimed to investigate the role of 11ß­hydroxysteroid dehydrogenase­1 (11ß­HSD1) during the development of hepatic fibrosis. An experimental rat model of liver fibrosis was induced using porcine serum. 11ß­HSD1 gene expression levels and enzyme activity during hepatic fibrogenesis were assessed. 11ß­HSD1 gene knockdown using small interfering RNA and overexpression were performed in LX2­human hepatic stellate cells (HSCs). HSCs were stimulated with transforming growth factor­ß1 (TGF­ß1). Cell cycle distribution, proliferation, collagen secretion and 11ß­HSD1 gene activity in HSCs were compared before and after stimulation. As hepatic fibrosis progressed, 11ß­HSD1 gene expression and activity increased, indicating a positive correlation with typical markers of liver fibrosis. 11ß­HSD1 inhibition markedly reduced the degree of fibrosis. The cell proliferation was increased, the number of cells in the G0/G1 phase decreased and the number of cells in the S and G2/M phases increased in the pSuper transfected group compared with the N group. In addition, the overexpression of 11ß­HSD1 enhanced the TGF­ß1­induced activation of LX2­HSCs and enzyme activity of connective tissue growth factor. 11ß­HSD1 knockdown suppressed cell proliferation by blocking the G0/G1 phase of the cell cycle, which was associated with HSC stimulation and inhibition of 11ß­HSD1 enzyme activity. In conclusion, increased 11ß­HSD1 expression in the liver may be partially responsible for hepatic fibrogenesis, which is potentially associated with HSC activation and proliferation.

Early hepatitis B viral DNA clearance predicts treatment response at week 96.

AIM: To investigate whether hepatitis viral DNA load at 24 wk of treatment predicts response at 96 wk in patients with chronic hepatitis B. METHODS: A total of 172 hepatitis B envelope antigen (HBeAg)-positive chronic hepatitis B patients who received initial treatment at 16 tertiary hospitals in Hunan Province, China were enrolled in this study. All patients received conventional doses of lamivudine and adefovir dipivoxil, telbivudine, entecavir dispersible tablets, or entecavir tablets for 96 wk. Patients who used other antiviral drugs or antitumor and immune regulation therapy were excluded. Patients were stratified into three groups according to their viral DNA load at 24 wk: < 10 IU/mL (group 1), 10-103 IU/mL (group 2), and > 103 IU/mL (group 3). Correlations of 24-wk DNA load with HBeAg negative status and HBeAg seroconversion at 96 wk were analyzed. Receiver operating characteristic curve analysis was used to test the predictive value of the HBV DNA load at 24 wk for long-term response. RESULTS: The rates of conversion to HBeAg negative status and HBeAg seroconversion rates were 53.7% and 51.9%, respectively, in group 1; 35.21% and 32.39% in group 2; and 6.38% and 6.38% in group 3. The receiver operating characteristic curves for the three subgroups revealed that the lowest DNA load (< 10 IU/mL) was better correlated with response at 96 wk than a higher DNA load (10-103 IU/mL). Nested PCR was used for amplifying and sequencing viral DNA in patients with a viral DNA load > 200 IU/mL at 96 wk; resistance mutations involving different loci were present in 26 patients, and three of these patients had a viral DNA load 10-103 IU/mL at 96 wk. CONCLUSION: Hepatitis B viral DNA load at 24 wk of antiviral treatment in patients with chronic hepatitis B is a predictor of the viral load and response rate at 96 wk.

[Analysis of the prophylactic effect of nucleosides against reactivation of HBV in HBsAg-positive patients with non-hepatic tumors after chemotherapy].

OBJECTIVE: To investigate the efficacy of nucleosides as a prophylactic agent against reactivation of hepatitis B virus (HBV) in HBsAg-positive patients with non-hepatic tumors after chemotherapy. METHODS: Fifty-eight patients with non-hepatic tumors were divided into prevention group and control group. The patients of prevention group received nucleosides as a prophylactic agent before chemotherapy and were compared with the control ones about the clinical manifestation of HBV reactivation. Then, the patients of the control group were divided into three groups according to antiviral drugs, use or not and time of the use. The patients having HBV reactivation but never received nucleosides were included in the group A, the patients receiving nucleosides after having HBV reactivation were divided into the group B, and the patients receiving nucleosides before HBV reactivation were divided into the group C. The progression, prognosis and curative effect among the three groups were compared. RESULTS: The rate of HBV reactivation, incidence of severe hepatitis, mortality rate of the control group (61.1%, 27.8%, 16.7%) were significantly higher than those of the prevention group (13.6%, 0, 0), and liver dysfunction was more serious than that in the prevention group. In the control group, all the 5 patients of group A died of liver failure. Of the 13 patients in the group B, 4 cases suffered from severe hepatitis and 1 of them died of the disease. Of the 18 patients in the group C, 4 cases suffered from HBV reactivation, but the clinical manifestation was milder than that of the group B. CONCLUSION: Nucleosides can be used as a prophylactic measure to prevent HBV reactivation. If chemotherapy had begun, the use of nucleosides may reduce the risk of HBV reactivation. Even if patients had suffered from HBV reactivation, the use of nucleosides may still help the recovery of liver function and improve prognosis.

Involvement of dimethylarginine dimethylaminohydrolase-2 in visfatin-enhanced angiogenic function of endothelial cells.

BACKGROUND: Visfatin, a new adipocytokine, was reported to promote angiogenesis. Dimethylarginine dimethylaminohydrolase (DDAH), which could regulate vascular endothelial growth factor (VEGF) expression in endothelial cells, is thought as a novel modulator of angiogenesis. The aim of the study was to investigate the role of DDAH2 in visfatin-induced angiogenesis in human umbilical vein endothelial cells (HUVECs). METHODS AND RESULTS: Visfatin could concentration- and time-dependently enhance cell migration and tube formation reflecting angiogenic capability of HUVECs. Moreover, visfatin upregulated both mRNA and protein expressions of DDAH2 and VEGF. Angiogenic effects of visfatin were attenuated by DDAH2 small interfering RNA. Visfatin-induced protein kinase B (Akt) phosphorylation and phosphoinositide 3 kinase (PI3K) inhibitors could suppress visfatin-induced upregulation of DDAH2 and VEGF expressions. CONCLUSIONS: Taken together, our results demonstrate that PI3K/Akt-mediated upregulation of DDAH2 expression plays a critical role in visfatin-promoted angiogenesis via regulating VEGF-dependent pathway.

[Immortalization of embryonic fibroblasts in heat shock transcription factor 1 knockout mouse].

OBJECTIVE: To establish immortalized embryonic fibroblast lines in heat shock transcription factor 1 (HSF1) HSF1-/- and HSF1+/+ mice and to provide experimental models to study the function of HSF1. METHODS: A mammalian expression vector (pSV3neo) containing the SV40 large T antigen was used to transfect the HSF1-/- and HSF1+/+ mouse embryonic fibroblast using Lipofectamine 2000. Colonies were screened by G418 and expanded to immortalized cell lines. PCR was used to detect the integration of the large T antigen with genome in the mouse embryonic fibroblast. Expression of SV40 large T antigen gene in expanded cells was identified by RT-PCR. HSP70 expression was examined by Western blot in the embryonic fibroblast lines. RESULTS: The stable growth and serial propagation were observed in the HSF1-/- and HSF1+/+ cell lines for six months. The mRNA of SV40 T antigen gene expressed in the two cell lines. HSP70 expression could not be induced in the heat-treated HSF1-/- mouse embryo fibroblasts. CONCLUSION: The immortalized cells of HSF1+/+ and HSF1-/- mouse embryo fibroblasts are successfully established.