Hepatitis B Virus Induces IL-23 Production in Antigen Presenting Cells and Causes Liver Damage via the IL-23/IL-17 Axis

IL-23 regulates myriad processes in the innate and adaptive immune systems, and is a critical mediator of the proinflammatory effects exerted by Th17 cells in many diseases. In this study, we investigated whether and how hepatitis B virus (HBV) causes liver damage directly through the IL-23 signaling pathway. In biopsied liver tissues from HBV-infected patients, expression of both IL-23 and IL-23R was remarkably elevated. In vivo observations also indicated that the main sources of IL-23 were myeloid dendritic cells (mDCs) and macrophages. Analysis of in vitro differentiated immature DCs and macrophages isolated from healthy donors revealed that the HBV surface antigen (HBsAg) efficiently induces IL-23 secretion in a mannose receptor (MR)-dependent manner. Culture with an endosomal acidification inhibitor and the dynamin inhibitor showed that, upon binding to the MR, the HBsAg is taken up by mDCs and macrophages through an endocytosis mechanism. In contrast, although the HBV core antigen (HBcAg) can also stimulate IL-23 secretion from mDCs, the process was MR- and endocytosis-independent. In addition, IL-23 was shown to be indispensible for HBsAg-stimulated differentiation of naïve CD4⁺ T cells into Th17 cells, which were determined to be the primary source of IL-17 in HBV-infected livers. The cognate receptor, IL-17R, was found to exist on the hepatic stellate cells and mDCs, both of which might represent the potential target cells of IL-17 in hepatitis B disease. These data provide novel insights into a yet unrecognized mechanism of HBV-induced hepatitis, by which increases in IL-23 expression, through an MR/endocytosis-dependent or -independent manner, produce liver damage through the IL-23/IL-17 axis.     

A Novel Zebrafish Xenotransplantation Model for Study of Glioma Stem Cell Invasion

Invasion and metastasis of solid tumors are the major causes of death in cancer patients. Cancer stem cells (CSCs) constitute a small fraction of tumor cell population, but play a critical role in tumor invasion and metastasis. The xenograft of tumor cells in immunodeficient mice is one of commonly used in vivo models to study the invasion and metastasis of cancer cells. However, this model is time-consuming and labor intensive. Zebrafish (Danio rerio) and their transparent embryos are emerging as a promising xenograft tumor model system for studies of tumor invasion. In this study, we established a tumor invasion model by using zebrafish embryo xenografted with human glioblastoma cell line U87 and its derived cancer stem cells (CSCs). We found that CSCs-enriched from U87 cells spreaded via the vessels within zebrafish embryos and such cells displayed an extremely high level of invasiveness which was associated with the up-regulated MMP-9 by CSCs. The invasion of glioma CSCs (GSCs) in zebrafish embryos was markedly inhibited by an MMP-9 inhibitor. Thus, our zebrafish embryo model is considered a cost-effective approach tostudies of the mechanisms underlying the invasion of CSCs and suitable for high-throughput screening of novel anti-tumor invasion/metastasis agents.     

Prevalence of HIV Infection and Associated Risk Factors among Men Who Have Sex with Men (MSM) in Harbin,P. R. China

Objective

To assess the prevalence of HIV infection and characteristically risk of factors which associated with HIV infection among MSM in Harbin, China.

Methods

A face-to-face questionnaire interview was conducted among 463 Men Who Have Sex with Men (MSM) who were recruited by the snowball sampling in Harbin from April, 2011 to July, 2011. The questionnaire mainly included demographics, AIDS knowledge, homosexual behavior and the status of intervention in MSM. Blood specimens were obtained and tested for the diagnoses of HIV, syphilis and hepatitis C virus (HCV). Associations between above exposed factors and HIV infection were analyzed using a univariate analysis and forward stepwise logistic regression.

Results

The prevalence of HIV and syphilis was 9.5 and 14.3%. The awareness rate of AIDS was 86.8%. The rate of unprotected sexual behavior was 57.6% of MSM during the past 6 months. The univariate analysis identified that the age (age≥35 years old), cohabitation, more than 10 years of homosexual behavior and more than 10 homosexual partners were risk factors which associated with the HIV infection, and that protected sex during the past 6 months was a protective factor for the HIV infection. The multivariate analysis identified that the duration of homosexual behavior and commercial sexual behavior were independent risk factors which associated with the HIV infection, and the protected sex during the past 6 months was a protective factor for the HIV infection.

Conclusion

The prevalence of HIV among MSM in Harbin has been rapidly increasing in the past few years. Targeted, tailored, and comprehensive interventions are urgently needed to prevent the HIV infection from MSM.     

Inhibition of mTOR Reduces Anal Carcinogenesis in Transgenic Mouse Model

The molecular mechanism of human anal squamous cell carcinoma (ASCC) is unclear, and the accumulating evidence indicate association of ASCC with the activation of the Akt/mTOR pathway. Here we describe a mouse model with spontaneous anal squamous cell cancer, wherein a combined deletion of Tgfbr1 and Pten in stratified squamous epithelia was induced using inducible K14-Cre. Histopathologic analyses confirmed that 33.3% of the mice showed increased susceptibility to ASCC and precancerous lesions. Biomarker analyses demonstrated that the activation of the Akt pathway in ASCC of the Tgfbr1 and Pten double knockout (2cKO) mouse was similar to that observed in human anal cancer. Chemopreventive experiments using mTOR inhibitor-rapamycin treatment significantly delayed the onset of the ASCC tumors and reduced the tumor burden in 2cKO mice by decreasing the phosphorylation of Akt and S6. This is the first conditional knockout mouse model used for investigating the contributions of viral and cellular factors in anal carcinogenesis without carcinogen-mediated induction, and it would provide a platform for assessing new therapeutic modalities for treating and/or preventing this type of cancer.     

Correction of Diabetic Erectile Dysfunction with Adipose Derived Stem Cells Modified with the Vascular Endothelial Growth Factor Gene in a Rodent Diabetic Model

The aim of this study was to determine whether adipose derived stem cells (ADSCs) expressing vascular endothelial growth factor (VEGF) gene can improve endothelial function, recover the impaired VEGF signaling pathway and enhance smooth muscle contents in a rat diabetic erectile dysfunction (DED) model. DED rats were induced via intraperitoneal injection of streptozotocin (40 mg/kg), and then screened by apomorphine (100 µg/kg). Five groups were used (n = 12/group)–Group 1 (G1): intracavernous injection of lentivirus-VEGF; G2: ADSCs injection; G3: VEGF-expressing ADSCs injection; G4: Phosphate buffered saline injection; G1–G4 were DED rats; G5: normal rats. The mean arterial pressure (MAP) and intracavernosal pressure (ICP) were measured at days 7 and 28 after the injections. The components of the VEGF system, endothelial, smooth muscle, pericytes markers in cavernoursal tissue were assessed. On day 28 after injection, the group with intracavernosum injection of ADSCs expressing VEGF displayed more efficiently and significantly raised ICP and ICP/MAP (p<0.01) than those with ADSCs or lentivirus-VEGF injection. Western blot and immunofluorescent analysis demonstrated that improved erectile function by ADSCs-VEGF was associated with increased expression of endothelial markers (VEGF, VEGF R1, VEGF R2, eNOS, CD31 and vWF), smooth muscle markers (a-actin and smoothelin), and pericyte markers (CD146 and NG2). ADSCs expressing VEGF produced a therapeutic effect and restored erectile function in diabetic rats by enhancing VEGF-stimulated endothelial function and increasing the contents of smooth muscle and pericytes.     

Exogenous Spermidine Promotes Somatic Embryogenesis of <i>Cunninghamia lanceolata</i> by Altering the Endogenous Phytohormone Content

In order to study how exogenous hormones in C. lanceolata (gymnosperm) regulate somatic embryogenesis, we measured the endogenous phytohormones of two genotypes with different somatic embryogenesis efficiency and found that an increase in endogenous concentrations of IAA and ABA may be correlated to more efficient somatic embryogenesis. By applying exogenous spermidine, we found that exogenous hormones may affect somatic embryogenesis efficiency through affecting the endogenous phytohormone content. Based on these results, further studies can be conducted whereby the concentration of exogenous hormones or the levels of endogenous phytohormones by molecular methods are regulated to promote somatic embryogenesis. Our research may benefit the long-term economic output of the forestry industry and lays the foundation to studying the molecular mechanism that controls somatic embryogenesis efficiency.     

暗黑菌(Atribacteria)的环境分布和功能特征

暗黑菌门包括OP9和JS1两大分支,成员大多为未培养微生物,在自然环境中广泛分布,并且在部分环境如厌氧海洋沉积物、地热环境以及油藏中为优势微生物。基于基因组信息的研究表明,暗黑菌为严格的厌氧微生物,同时具有降解糖类、小分子酸、短链正构烷烃的能力,在地球碳循环过程中可能扮演着重要的角色。然而,由于缺乏相应代表性的纯培养菌株,对于暗黑菌的生理生化功能推测仍有待验证。文章概述了暗黑菌的发现及发展历史,分析了其环境分布和多样性,简述了目前提出的三种代谢方式,提出了未来暗黑菌的研究发展方向。     

Sinomenine hydrochloride enhancement of the inhibitory effects of anti-transferrin receptor antibody-dependent on the COX-2 pathway in human hepatoma cells

Transferrin receptor (TfR) has been used as a target for the antibody-based therapy of cancer due to its higher expression in tumors relative to normal tissues. Great potential has been shown by anti-TfR antibodies combined with chemotherapeutic drugs as a possible cancer therapeutic strategy. In our study, we investigated the anti-tumor effects of anti-TfR monoclonal antibody (mAb) alone or in combination with sinomenine hydrochloride in vitro. Results suggested that anti-TfR mAb or sinomenine hydrochloride could induce apoptosis, inhibit proliferation, and affect the cell cycle. A synergistic effect was found in relation to tumor growth inhibition and the induction of apoptosis when anti-TfR mAb and sinomenine hydrochloride were used simultaneously. The expression of COX-2 and VEGF protein in HepG2 cells treated with anti-TfR mAb alone was increased in line with increasing dosage of the agent. In contrast, COX-2 expression was dramatically decreased in HepG2 cells treated with sinomenine hydrochloride alone. Furthermore, we demonstrated that the inhibitory effects of sinomenine hydrochloride and anti-TfR mAb administered in combination were more prominent than when the agents were administered singly. To sum up, these results showed that the combined use of sinomenine hydrochloride and anti-TfR mAb may exert synergistic inhibitory effects on human hepatoma HepG2 cells in a COX-2-dependent manner. This finding provides new insight into how tumor cells overcome the interference of iron intake to survive and forms the basis of a new therapeutic strategy involving the development of anti-TfR mAb combined with sinomenine hydrochloride for liver cancer.     

A functional polymorphism in interleukin-1α (IL1A) gene is associated with risk of alopecia areata in Chinese populations

Alopecia areata (AA) is an inflammatory hair loss disorder with a major genetic component, which may cause great psychosocial distress for those affected. Studies have shown that interleukin-1 (IL-1) is a very potent inducer of hair loss and a significant human hair growth inhibitor. The 4-bp insertion/deletion (Indel) polymorphism (rs3783553) within the 3′ untranslated regions of IL1A gene has been suggested to be associated with risk of various types of cancers, possibly through regulating expression of IL-1α levels. In the current study, we estimated the susceptibility to AA associated with rs3783553 in two independent case–control panels of Eastern and Southern Chinese populations, totally containing 313 AA cases and 626 healthy controls. Logistic regression analysis showed that the heterozygote and the homozygote 4-bp ins/ins confer a significantly lower risk of AA in both panels and total subjects [odds ratio (OR) = 0.55, 95% confidence interval (C.I.) = 0.41–0.75, P = 6.24 × 10^− 5; OR = 0.47, 95% C.I. = 0.28–0.76, P = 0.001, respectively]. Stratification analysis based on age onset showed that the protective roles of ins/del and ins/ins genotype against developing AA was more obvious in AA patients with early age onset (< 30 years) under dominant model (OR = 0.48, 95% C.I. = 0.29–0.77, P = 0.001). The results of luciferase assay showed that rs3783553 could influence expression of IL-1α in a miR-122 dependant manner. Taken together, our results suggested that the IL1A 4-bp indel polymorphism may be a marker for genetic susceptibility to patchy (mild) AA in Chinese populations, likely through miR-122 mediated regulation.     

DNA methylation and MeCP2 regulation of PTCH1 expression during rats hepatic fibrosis

Hepatic stellate cell (HSC) activation plays an important role in liver fibrogenesis. Transdifferentiation of quiescent hepatic stellate cells into myofibroblastic-HSCs is a key event in liver fibrosis. The methyl-CpG-binding protein MeCP2 which promotes repressed chromatin structure is selectively detected in myofibroblasts of diseased liver. MeCP2 binds to methylated CpG dinucleotides, which are abundant in the promoters of many genes. Treatment of HSCs with DNA methylation inhibitor 5-aza-2′- deoxycytidine (5-azadC) prevented proliferation and activation. Treatment with 5-azadC prevented loss of Patched (PTCH1) expression that occurred during HSCs activation. In a search for underlying molecular medchanisms, we investigated whether the targeting of epigenetic silencing mechanisms could be useful in the treatment of PTCH1-associated fibrogenesis. It was indicated that hypermethylation of PTCH1 is associated with the perpetuation of fibroblast activation and fibrosis in the liver. siRNA knockdown of MeCP2 increased the expressions of PTCH1 mRNA and protein in hepatic myofibroblasts. These data suggest that DNA methylation and MeCP2 may provide molecular mechanisms for silencing of PTCH1.