Oleanolic acid derivative alleviates cardiac fibrosis through inhibiting PTP1B activity and regulating AMPK/TGF-ß/Smads pathway.

Cardiac fibrosis (CF) in response to persistent exogenous stimuli or myocardial injury results in cardiovascular diseases (CVDs). Protein tyrosine phosphatase 1B (PTP1B) can promote collagen deposition through regulating AMPK/TGF-ß/Smads signaling pathway, and PTP1B knockout improves cardiac dysfunction against overload-induced heart failure. Oleanolic acid (OA) has been proven to be an inhibitor of PTP1B, and its anti-cardiac remodeling effects have been validated in different mouse models. To improve the bioactivity of OA and to clarify whether OA derivatives with stronger inhibition of PTP1B activity have greater prevention of cardiac remodeling than OA, four new OA derivatives were synthesized and among them, we found that compound B had better effects than OA in inhibiting cardiac fibrosis both in vivo in the isoproterenol (ISO)-induced mouse cardiac fibrosis and in vitro in the TGF-ß/ISO-induced 3T3 cells. Combining with the results of molecular docking, surface plasmon resonance and PTP1B activity assay, we reported that OA and compound B directly bound to PTP1B and inhibited its activity, and that compound B showed comparable binding capability but stronger inhibitory effect on PTP1B activity than OA. Moreover, compound B presented much greater effects on AMPK activation and TGF-ß/Smads inhibition than OA. Taken together, OA derivative compound B more significantly alleviated cardiac fibrosis than OA through much greater inhibition of PTP1B activity and thus much stronger regulation of AMPK/TGF-ß/Smads signaling pathway.

The PIWI-specific insertion module helps load longer piRNAs for translational activation essential for male fertility.

PIWI-clade proteins harness piRNAs of 24-33 nt in length. Of great puzzles are how PIWI-clade proteins incorporate piRNAs of different sizes and whether the size matters to PIWI/piRNA function. Here we report that a PIWI-Ins module unique in PIWI-clade proteins helps define the length of piRNAs. Deletion of PIWI-Ins in Miwi shifts MIWI to load with shorter piRNAs and causes spermiogenic failure in mice, demonstrating the functional importance of this regulatory module. Mechanistically, we show that longer piRNAs provide additional complementarity to target mRNAs, thereby enhancing the assembly of the MIWI/eIF3f/HuR super-complex for translational activation. Importantly, we identify a c.1108C>T (p.R370W) mutation of HIWI (human PIWIL1) in infertile men and demonstrate in Miwi knock-in mice that this genetic mutation impairs male fertility by altering the property of PIWI-Ins in selecting longer piRNAs. These findings reveal a critical role of PIWI-Ins-ensured longer piRNAs in fine-tuning MIWI/piRNA targeting capacity, proven essential for spermatid development and male fertility.

Risk factors for poor outcome in posterior reversible encephalopathy syndrome: systematic review and meta-analysis.

BACKGROUND: The roles of clinical etiology and symptoms, imaging findings and biochemical parameters in predicting the prognosis of posterior reversible encephalopathy syndrome (PRES) have not been well-characterized. We perform a meta-analysis of all published studies to assess the value of various risk factors in predicting the prognosis of PRES. METHODS: Searches of the PubMed, EMBASE, Cochrane Library, and Web of Science databases were performed to identify the eligible studies. The odds ratios (ORs) with their corresponding 95% confidence interval (CI) for related risk factors were used to calculate the pooled estimates of the outcomes. RESULTS: Six studies with 448 cases were included in the meta-analysis. Hemorrhage was associated with high risk for poor outcome in patients with PRES. Toxemia of pregnancy (pre-eclampsia/eclampsia) was associated with improved outcome in PRES patients. Cytotoxic edema was noted to be related to poor outcome, but did not show statistical significance. The pooled OR for hemorrhage, pre-eclampsia/eclampsia, cytotoxic edema was 4.93 (95% CI: 3.94-6.17; P<0.00001), 0.24 (95% CI: 0.15-0.40; P<0.00001) and 2.59 (95% CI: 0.84-7.99; P=0.10), respectively. CONCLUSIONS: PRES patients with hemorrhage or cytotoxic edema are likely to have poor outcomes. Pre-eclampsia/eclampsia is associated with reduced risk of poor outcome in patients with PRES.

Modulation of Tim-3 Expression by Antigen-Dependent and -Independent Factors on T Cells from Patients with Chronic Hepatitis B Virus Infection.

T-cell immunoglobulin domain and mucin domain-containing molecule-3 (Tim-3) was up-regulated on viral specific T cells and contributed to T cells exhaustion during chronic hepatitis B virus (HBV) infection. However, modulation of Tim-3 expression was still not fully elucidated. To evaluate the potential viral and inflammatory factors involved in the inductor of Tim-3 expression on T cells, 76 patients with chronic HBV infection (including 40 chronic hepatitis B [CHB] and 36 asymptomatic HBV carriers [AsC]) and 40 of normal controls (NCs) were enrolled in this study. Tim-3 expressions on CD4+ and CD8+ T cells were assessed in response to HBV-encoding antigens, HBV peptide pools, and common γ-chain (γc) cytokines stimulation by flow cytometry. HBV peptides and anti-CD3/CD28 directly induced Tim-3 expression on T cells. γc cytokines also drive Tim-3 up-regulations on both CD4+ and CD8+ T cells in patients with chronic HBV infection. However, γc cytokines did not enhance the Tim-3 inductions by either anti-CD3/CD28 or HBV peptides stimulation. Furthermore, γc cytokines-mediated Tim-3 induction could not be abrogated by γc cytokine receptor-neutralizing antibodies. The current results suggested that elevation of Tim-3 expression on T cells could be regulated by both antigen-dependent and -independent manner in patients with chronic HBV infection. The role of γc cytokines in modulation of inhibitory pathway might be evaluated as immunotherapies in humans.

Epidemiological studies of esophageal cancer in the era of genome-wide association studies.

Esophageal cancer (EC) caused about 395000 deaths in 2010. China has the most cases of EC and EC is the fourth leading cause of cancer death in China. Esophageal squamous cell carcinoma (ESCC) is the predominant histologic type (90%-95%), while the incidence of esophageal adenocarcinoma (EAC) remains extremely low in China. Traditional epidemiological studies have revealed that environmental carcinogens are risk factors for EC. Molecular epidemiological studies revealed that susceptibility to EC is influenced by both environmental and genetic risk factors. Of all the risk factors for EC, some are associated with the risk of ESCC and others with the risk of EAC. However, the details and mechanisms of risk factors involved in the process for EC are unclear. The advanced methods and techniques used in human genome studies bring a great opportunity for researchers to explore and identify the details of those risk factors or susceptibility genes involved in the process of EC. Human genome epidemiology is a new branch of epidemiology, which leads the epidemiology study from the molecular epidemiology era to the era of genome wide association studies (GWAS). Here we review the epidemiological studies of EC (especially ESCC) in the era of GWAS, and provide an overview of the general risk factors and those genomic variants (genes, SNPs, miRNAs, proteins) involved in the process of ESCC.

Estrogen and its receptor enhance mechanobiological effects in compressed bone mesenchymal stem cells.

Mechanical stimulation and estrogen have been proven to be two important factors in promoting mesenchymal stem cell activity, which is closely associated with bone formation, mass maintenance and remodeling. However, the superposition effects of mechanical stimulation and estrogen on stem cells remain unknown. It is also unclear if the estrogen receptor (ER) plays only a key role in estrogen signaling or if it is also involved in the mechanotransduction of stem cells. To investigate the role of estrogen and its receptors in the mechanobiological effects in bone mesenchymal stem cells (BMSCs), isolated mesenchymal stem cells from bone marrow were exposed to mechanical pressure under additional estrogen treatment or ER blockade. Cell proliferation was examined using an MTT assay and alkaline phosphatase (ALP) activity was determined by a modified enzyme kinetic method. Alignment of the cytoskeleton was observed by Coomassie brilliant blue staining and F-actin fluorescent staining. Cellular ultrastructure was observed under transmission electron microscope. Expression of ERα was investigated using Western blot analysis. Results indicated that mechanical pressure promoted cell proliferation, ALP activity, ERα expression and F-actin stress fiber formation. Overall, this effect was enhanced by the addition of estrogen and inhibited by ER blockade. We concluded that pressure stimulated proliferation and differentiation capability via F-actin transduction in BMSCs. The effects were enhanced by the addition of estrogen, and the ER plays an important role in regulating mechanobiological effects and the mechanotransduction processes of BMSCs.

Effects of intestinal intervention on bacterial translocation in a rat model of acute liver failure in vivo.

BACKGROUND/AIMS: The study aimed to confirm bacterial translocation (BT) in rats with acute liver failure (ALF), to explore the correlation between the concentration of lipopolysaccharides and Toll-like receptor 4 (TLR4) expression, and further, to evaluate the curative effects of lactulose and montmorillonite (smecta) in this setting. METHODS: D-Galactosamine was injected into the abdominal cavity of rats to induce ALF. Escherichia coli JM109 labeled with enhanced green fluorescent protein was administered to track BT. Simultaneously, the rats were given lactulose or smecta. Blood samples were collected for measuring liver function, cytokines, endotoxins, and TLR4 expression. Representative tissue specimens from the liver, spleen, and mesenteric lymph nodes were aseptically harvested for bacterial identification by agarose gel electrophoresis, laser scanning confocal microscopy, and flow cytometry. RESULTS: BT occurred in ALF, accompanied by impaired liver function with increased cytokines, endotoxins, and TLR4 expression. After the treatment with lactulose or smecta, all these parameters decreased, including the relative quantity of translocated bacteria while albumin increased. Furthermore, compared with the lactulose treatment group, the parameters in the smecta treatment group improved. Moreover, in the group in which smecta was given for prophylaxis, there was greater improvement than with treatment. CONCLUSION: Intestinal intervention with lactulose or smecta can ameliorate BT; moreover, smecta has a better effect than lactulose, and its preventive effect was also better than its therapeutic effect.

[The mechanism of HBV infection of human trophoblast cell].

OBJECTIVE: To observe the changes of human trophoblast cells after infected with hepatitis B virus. METHODS: HBV positive serum was used to infect human trophoblast cells in vitro. HBsAg in cell culture medium were detected by ELISA method and HBV DNA in cell culture medium and cells were detected by PCR method. HBV fluorescence polymerase chain reaction diagnose kit were used to detect the HBV DNA concentration. Ultra structure of trophoblast cells were observed with transmission electron microscopy (TEM). RESULTS: HBsAg could be detected in infection group by ELISA. Infection group cell culture medium and infection group cells were HBV DNA positive. HBV DNA concentrations in HBV infection cell culture medium in 0, 12, 36, 60, 84 h after extensively PBS washed were < 10(3), 3 x 10(4), 6 x 10(5), 5 x 10(5), 3 x 10(5) copies/mL. HBV infected trophoblast cells were found many forms of endosomes, some of which contents virus like particle. CONCLUSION: HBV might take advantage of clathrin-mediated endocytosis to enter trophoblast cell, which might lead to cell infection or across the cell bar by transcytosis.

[Hepatitis B immunoglobulins blocking hepatitis B virus infection of trophoblast cell culture in vitro].

OBJECTIVE: To determine the role of hepatitis B Immunoglobulins (HBIG) in blocking hepatitis B virus (HBV) infection of trophoblast cell culture in vitro. METHODS: Trophoblast cells were placed in the six-well cluster dishes and incubated with 10% fetal calf serum/Dubecco's modified Eagle's Medium (10% FCS DMEM) at 37 degrees C with 5% CO2 in air. At 24 h after plating cells were subjected to experiment. Group A: cells were cultured with 0.5 ml HBV positive serum plus 3 ml 2% FCS DMEM; Group B: cells were cultured with 3 ml 2% FCS DMEM plus 0.5 ml HBV positive serum pretreated with 80 U HBIG for 30 min at 37 degrees C; Group C: cells were cultured with 3 ml 2% FCS DMEM plus 0.5 ml HBV positive serum pretreated with 40 U HBIG for 30 min at 37 degrees C; Group D: cells were cultured with 3 ml 2% FCS DMEM plus 40 U HBIG for 30 min before 0.5 ml HBV positive serum was added; Group E: cells were cultured with 40 U HBIG plus 3 ml 2% FCS DMEM; Group F: cells were cultured with HBV negative serum plus 3 ml 2% FCS DMEM. Twenty-four hours later the inoculums were removed, and the cells were extensively washed with 0.01 mol/L phosphate-buffered saline (PBS). After PBS washing, 4 ml 2% FCS DMEM was added to each well and the medium was collected every 12 hours. Enzyme-Linked Immunosorbent Assay (ELISA) method was used to detect HBsAg in culture medium (absorption value, A). HBV DNA in cell culture medium was detected by polymerase chain reaction (PCR). RESULTS: Before PBS washing, the A value of groups A, B, C, D, E, F were 2.697, 0.040, 0.102, 0.198, 0.036, 0.040 respectively. The cell culture medium in groups of A, B, C, and D were HBV DNA positive, groups of E, F were HBV DNA negative. From 12 hours to 84 hours, the average A value of groups A, B, C, D, E and F was 1.55 +/- 0.27, 0.032 +/- 0.016, 0.100 +/- 0.087, 0.052 +/- 0.044, 0.034 +/- 0.020, 0.034 +/- 0.022 respectively. The A value of groups A was significantly higher than those of other groups (P < 0.01). Cell culture medium at 84 hours of group A was HBV DNA positive and those of group B, C, D, E, F were HBV DNA negative. CONCLUSION: HBIG could effectively block HBV infection of trophoblast cell culture in vitro.

[In vitro infection of human hepatoma (Hep G2) cell line by hepatitis B virus positive serum].

OBJECTIVE: To establish a culture system of HBV positive serum infected Hep G2 cells in vitro. METHODS: Hep G2 cells were seeded into six-well cluster dishes, at 1 x 10(-6) cells per well and incubated with 3 ml 10% fetal calf serum/ Dulbecco's modified Eagle's medium (10% FCS/DMEM) at 37 degrees in 5% CO2 air. At 24 h after plating, infection group Hep G2 cells were cultured with 0.5 ml HBV positive serum, in control group HBV negative serum was used, 24 h later the inoculums was removed. The cells were then extensively washed with 0.01 mol/L phosphate-buffered saline (PBS). After washing with PBS, 4 ml 2% FCS/DMEM were added to each well and the medium was collected every 12 h. ELISA method was used to detect HBsAg in culture medium. HBV DNA in cells and culture medium was detected by PCR. RESULTS: In infection group, HBsAg could be detected from cell culture medium from 12 h (after PBS washed) to 84 h. HBV DNA could be detected by PCR in culture medium and cells. CONCLUSION: Infection of Hep G2 cells by HBV positive serum is feasible.

[Meta-analysis on the relationship between tobacco smoking, alcohol drinking and p53 alteration in cases with esophageal carcinoma].

OBJECTIVE: To investigate the relationship between tobacco smoking, drinking and p53 alteration in esophageal carcinoma. METHODS: Literature on the relationship between p53 alteration in esophageal carcinoma and tobacco smoking, drinking through Meta-analysis were reviewed. RESULTS: In 14 selected papers related to tobacco smoking, pooled odds ratio (OR) of tobacco smoking with P53 overexpression and p53 alteration were 1.99 (95% CI: 1.30- 3.06) and 1.64 (95% CI: 1.13 - 2.37), respectively (P < 0.05). Pooled OR of tobacco smoking with p53 mutation was 1.11 (95% CI: 0.47 - 2.76) (P > 0.05). In 11 selected papers on alcohol drinking, pooled OR of drinking with P53 overexpression, p53 mutation and p53 alteration were 1.30 (95% CI: 0.83 - 2.04), 1.13 (95% CI: 0.67 - 1.90) and 1.22 (95% CI: 0.87 - 1.72) respectively (P > 0.05). CONCLUSION: There were significant relations between tobacco smoking and p53 alteration while there were no significant relations between alcohol drinking and p53 alteration.

Genetic susceptibility and environmental factors of esophageal cancer in Xi'an.

AIM: To analyse the role of genetic susceptibility and environmental factors in the process of esophageal cancer (EC) formation in Xi'an, China. METHODS: A hospital based case-control study, combined with molecular epidemiological method, was carried out. A total of 127 EC cases and 101 controls were interviewed with questionnaires containing demographic items, habit of tobacco smoking, alcohol drinking, and family history of EC. Polymorphism of CYP1A1 and GSTM1 of 127 EC cases and 101 controls were detected by PCR method. The interactions between genetic susceptibility and environmental factors were also discussed. RESULTS: Tobacco smoking, alcohol drinking and a family history of EC were risk factors for EC with an OR of 2.04(95% CI 1.15-3.60), 3.45(95% CI 1.74-6.91), 3.14 (95% CI 1.28-7.94), respectively. Individuals carrying CYP1A1 Val/Val genotype compared to those with CYP1A1 Ile/Ile genotype had an increased risk for EC (OR 3.35, 95% CI 1.49-7.61). GSTM1 deletion genotype was a risk factor for EC (OR1.81, 95% CI 1.03-3.18). Gene-environment interaction analysis showed that CYP1A1 Val/Val genotype, GSTM1 deletion genotype had synergetic interactions with tobacco smoking, alcohol drinking and family history of EC. CONCLUSION: Tobacco smoking, alcohol drinking and a family history of EC are risk factors for EC. CYP1A1 Val/Val and GSTM1 deletion genotypes are genetic susceptibility biomarkers for EC. There are synergic interactions between genetic susceptibility and environmental factors.

Relationship of tobacco smoking CYP1A1 GSTM1 gene polymorphism and esophageal cancer in Xi'an.

AIM: To analyze the association of tobacco smoking polymorphism of CYP1A1 (7th exon) and GSTM1 genotype and esophageal cancer(EC) in Xi'an. METHODS: A hospital based case-control study, with molecular epidemiological method, was carried out. Polymorphism of CYP1A1 and GSTM1 of samples from 127 EC cases and 101 controls were detected by PCR method. RESULTS: There were no significant difference of age and gender between cases and controls. Tobacco smoking was the main risk factor OR=1.97;95% CI=1.12-3.48 for EC in Xi'an. The proportions of CYP1A1 Ile/Ile, Ile/Val and Val/Val gene types in cases and controls was 19.7% 45.7% 34.6% and 30.7%,47.5%, 21.8% respectively(P=0.049). Individuals with CYP1A1 Val/Val genotype compared to those with CYP1A1 Ile/Ile genotype had higher risk for EC increased (OR=2.48, 95%CI=1.12-5.54). The proportions of GSTM1 deletion genotype in cases and controls were 58.3% and 43.6%(OR=1.81, 95%CI=1.03-3.18, P=0.028). Analysis of gene-environment interaction showed that tobacco smoking and CYP1A1 Val/Val genotype; tobacco smoking and GSTM1 deletion genotype had synergism interaction respectively. Analysis of gene-gene interaction did not find synergistic interaction between these two genes. But in GSTM1 deletion group there was significant difference of distribution of CYP1A1 genotype between cases and controls (P=0.011). CONCLUSION: CYP1A1 Val/Val and GSTM1 deletion genotypes are genetic susceptibility biomarkers for EC. The risk increases, when person with CYP1A1 Val/Val and/or GSTM1 deletion genotype. And these two-metabolic enzymes seem to have interactions with tobacco smoking, in which the mechanism still needs further study.