Azithromycin attenuates pulmonary inflammation and emphysema in smoking-induced COPD model in rats.

INTRODUCTION: The role of inflammation and immunity in COPD treatment is increasingly being recognized. The relationship between anti-inflammation/immunoregulation and emphysema in COPD lungs remains to be elucidated. The aim of this study was to investigate the effects of azithromycin (Azm) on the development of emphysema in smoking-induced COPD in rats. METHODS: Sprague-Dawley rats (n = 50) were randomly assigned to normal, COPD, saline-treated, Azm-treated, and levofloxacin-treated (Lev) groups. The effects of treatment were assessed by measuring the levels of vascular endothelial growth factor (VEGF) by enzyme-linked immunosorbent assay and measuring the numbers of neutrophil and macrophage in bronchoalveolar lavage fluid, vascular endothelial growth factor (VEGF) and VEGF receptor-2 (VEGFR2) protein expression by western blotting. Lung function measurements and histopathological evaluations (mean linear intercept and destructive index) were performed. RESULTS: FEV0.3/FVC and peak expiratory flow were lower in the COPD group than in the normal group. Mean linear intercept and destructive index were lower in the Azm-treated group than in the COPD, saline-treated, and Lev-treated groups. The numbers of neutrophil and macrophage in bronchoalveolar lavage fluid were lower in the Azm-treated group than in the COPD, saline-treated, and Lev-treated groups. As confirmed by western blotting, the levels of VEGF in lung homogenates were higher in the Azm-treated group than in the COPD, saline-treated, and Lev-treated groups. VEGFR2 protein expression was higher in the Azm-treated group than in the COPD, saline-treated, and Lev-treated groups. CONCLUSIONS: Azm attenuates pulmonary emphysema by partly reversing the decrease in the numbers of inflammatory cells (neutrophil and macrophage) and VEGF secretion and VEGFR2 protein expression in smoking-induced COPD in rats.

[Hepatitis B e antigen from chronic hepatitis B patients induces Th1/Th2 cytokine imbalance in vitro].

OBJECTIVE: To study the immunoregulatory effect of hepatitis B virus (HBV) e antigen (HBeAg) on peripheral blood monocytes (PBMCs). METHODS: PBMCs were isolated from patients with chronic hepatitis B (CHB; both HBeAg- and HBeAg+) and healthy controls, and cultured with recombinant HBeAg. The HBeAg-induced changes in expression of PD-1/PD-L1 were measured by flow cytometry of the cells and in secreted cytokines were measured by enzyme-linked immunosorbent assay of the supernatants. Comparisons between two groups were made by the independent-samples t-test; the relationship between PD-1/B7-H1 level and HBV DNA copy number was evaluated by Spearman's correlation analysis. RESULTS: Exposure to HBeAg led to a significant decrease in CD3+CD4+ T lymphocyte-specific expression of IFNa for both the CHB patients' and healthy controls' samples (t = 2.382 and -4.190 respectively, P less than 0.01). For the HBeAg- CHB patients' and healthy controls' samples, the HBeAg exposure led to increased levels of secreted cytokines IL-6, IL-10 and TNFa (t = 2.504, 3.583 and 4.324, P less than 0.01 and t = 3.542, 6.246 and 5.273, P less than 0.01 respectively) and of CD14+ PBMC-specific expression of PD-L1 (t = 4.815 and 3.454, P less than 0.05 respectively). Compared to the HBeAg-negative CHB patients' and healthy controls' samples, the HBeAg+ CHB patients' samples had significantly lower CD3+CD4+ T cell-specific expression of IFNa (t = -3.177 and -4.541, P less than 0.01 respectively), but significantly higher levels of secreted IL-4 (t = 3.382 and 4.393, P less than 0.01 respectively), of CD3+ T cells-specific expression of PD-1/PD-L1 (t = 4.755, 2.942 and 4.518, 4.595, P less than 0.01 respectively), and of CD14+ T cells-specific expression of PD-L1 (t = 5.092 and 5.473, P less than 0.01 respectively). The CD3+ T cells-specific expression of PD-L1 was significantly higher in the samples from HBeAg- CHB patients than from the healthy controls (t = 3.214, P less than 0.01). CONCLUSION: HBeAg was able to down-regulate the production of Th1-type cytokines (IFNgamma), and up-regulate the secretion of Th2-type cytokines (IL-6, IL-10) and the expression of PD-1/PD-L1on monocytes. These changes are conducive to the formation of immune tolerance to HBV. Therefore, HBeAg may play an important role in immune tolerance to chronic HBV infection.

The association of NAT1 polymorphisms and colorectal carcinoma risk: evidence from 20,000 subjects.

Published data on the association between N-acetyltransferase 1 (NAT1) gene polymorphisms and colorectal carcinoma (CRC) susceptivity are inconclusive. To derive a more precise estimation of the association, we conducted this meta-analysis. Data were collected from electronic databases: PubMed, EMBASE, with the last report up to May 2010. The odds ratio (OR) and corresponding 95% confidence intervals (CIs) were used to assess the strength of the association. A total of 20 individual studies including 8,219 cases and 11,498 controls based on the search criteria were involved. Meta-analysis was performed for slow versus rapid acetylation genotypes of NAT1. We found no association between NAT1 polymorphisms and CRC in overall population (OR = 0.96, 95% CI = 0.88-1.05 P = 0.05 for heterogeneity) without significant publication bias present. In subgroup analyses, similar results were found in different ethnicities, source of controls, genotyping methods and adjustment. Current meta-analysis suggests that lack of association between the NAT1 polymorphisms and individual risk to CRC.

[The study of expansion and function HBV special interferon-γ secreting human T lymphocytes in vitro].

AIM: To expand HBV special interferon-γ secreting human T lymphocytes in vitro and sustain the ability to recognize special T cell epitodes of HBcAg. METHODS: After stimulated by peptide 22 hours, feeded with autologous peripheral blood mononuclear cells ( PBMCs) deproliferated by mitomycin C and low concentration of IL-2 to expand in vitro for other 4 weeks. Then cells were collected and tested by flow cells assay every week. The ability of these cells to recognize special epitodes was tested by enzyme linked immunospot assay in which autologous lymphoblastoid cell lines (LCLs) produced from PBMC was transfected by epstein-barr virus pulsed with peptides and used as target cell. RESULTS: HBV special interferon-secreting human T lymphocytes were selected and expanded more than 1000 times in vitro. The ability of the T cells to recognize special epitodes is as same as unexpanded cells and the proportion of CD4 and CD8 positive cells likely remained native state. CONCLUSION: HBV special interferon-γ secreting T lymphocytes are effectively expanded in vitro and keep the ability to recognize stringently special T cell epotides.

Involvement of mTOR and survivin inhibition in tamoxifen-induced apoptosis in human hepatoblastoma cell line HepG2.

Patients with advanced hepatocellular carcinoma (HCC) have shown to benefit from tamoxifen treatment. The mechanisms of tamoxifen effects in HCC, however, are not yet clearly understood. The PI3K/Akt/mTOR signal pathway is involved in cell proliferation, tumorigenesis, and apoptosis. Over-expression of survivin has played an important role in leading to antiapoptosis. The current study investigated changes in mTOR pathway and survivin expression in hepatocarcinoma cell line HepG2 treated with tamoxifen. We detected apoptosis of hepatocarcinoma cells by flow cytometry assay. Survivin transcription level and p70S6k was demonstrated by PCR, dual-luciferase reporter assay and western blot analysis respectively. Our results are showed as follows: tamoxifen leads to apoptosis of the cells, and reduction in survivin expression, as well as a dramatic reduction in the activated form of p70S6 kinase. Twenty micromoles tamoxifen treatment significantly depresses transcription of survivin mRNA. Treating HepG2 cells with rapamycin, a specific mTOR inhibitor, significantly reduce survivin protein level but did not affect survivin transcription, which indicated that tamoxifen and rapamycin were synergistic in regards to down-regulation of survivin expression in hepatocellular carcinoma cells. Our results suggest that tamoxifen down-regulate survivin expression in HepG2 cells is mediated by transcriptional and posttranscriptional level via PI3K/Akt/mTOR pathway to induce apoptosis.

[Down-regulation of mTOR activity and survivin expression during tamoxifen-induced apoptosis in hepatoblastoma cells].

OBJECTIVE: The aim of this study was to investigate the changes in mTOR activity and survivin expression in liver cancer cell line HepG2 cells treated with tamoxifen. METHODS: Survivin transcription level and p70S6K was demonstrated by PCR, dual-luciferase reporter assay and Western blot analysis, respectively, and the apoptosis in the HepG2 cells was detected by flow cytometry. RESULTS: Tamoxifen leads to apoptosis of the cells and reduction in survivin expression, as well as a dramatic reduction in the activated form of p70S6K. Treating HepG2 cells with rapamycin, a specific mTOR inhibitor, significantly reduced the survivin protein level but not affected the survivin transcription, indicating that tamoxifen and rapamycin were synergistic in regards to down-regulation of survivin expression in hepatocellular carcinoma cells. CONCLUSIONS: Our results suggest that tamoxifen down-regulates survivin expression in HepG2 cells and it is mediated by transcriptional and post-transcriptional level via PI3K/Akt/mTOR pathway to induce apoptosis.

[Establishment of long-term culture system for human B cells derived from peripheral blood mononuclear cells activated via soluble CD40 ligand].

OBJECTIVE: To develop a method for long-term culture of human B cells from peripheral blood mononuclear cells (PBMCs) by means of human soluble CD40 ligand (sCD40L), and to investigate the proliferation and antigen-presenting function of the CD40-activated B cells. METHOD: Peripheral blood sample of 30 ml was collected from a healthy person. PBMCs were isolated and cultured in the presence of sCD40L. Flow cytometry was used to examine the proliferation, DNA cycle, and cell surface markers: CD86, CD80, major histocompatibility complex (MHC) class II, and MHC Class I of the B cells. The cells cultured for 45 days were divided into 2 groups: Group 1 incubated with the fluorescein isothiocyanate (FITC)-conjugated hepatitis-B core antigen (HBcAg-FITC) and Group 2 used as control group. Eighteen hours later cytometry and fluorescence microscopy were used to detect the peptide pulsing. RESULTS: The B cells could be cultured up to 50 days in the sCD40L culture system. The ratio of B cells in the PBMCs was 8.21% at the beginning, and increased to 70.67% by day 47, and the B cell absolute count was 6.56 x 10(5) at the beginning and increased to 8.61 x 10(6) at day 50, about 10 times higher. sCD40L promoted a strong up-regulation of cell surface markers. The expression rates of CD80, CD86, MHC-II, and MHC-I of the sCD40L-activated B cells were 83.97%, 84.73%, 99.59%, and 98.70% respectively. Flow cytometry showed that 98.10% of the B cells co-incubated with HBcAg-FITC were loaded with HBcAg. Fluorescence microscopy showed that the HBcAg was in the cytoplasm of the B cells. CONCLUSION: A human sCD40L culture system has been developed with the ability to culture human peripheral blood B cells, thus realizing the long-term proliferation and activation of human peripheral blood B cells that function as antigen-presenting cells.

[Insulin/PI3K signalling pathway regulates the expression of survivin in liver cancer HepG2 cells].

OBJECTIVE: To determine the expression level changes of survivin, a inhibitor of apoptosis protein, followed by activation of insulin receptors in human hepatocellular carcinoma HepG2 cell line, and to investigate the signalling pathway involved in the regulation. METHODS: Human hepatocellular carcinoma HepG2 cells were treated with insulin alone or pre-treated with LY294002, a specific inhibitor of PI3K signalling pathway, to determine whether blocking PI3K signaling can attenuate the up-regulation of survivin expression. Real time RT-PCR and Western blot analysis were used to measure survivin mRNA and protein changes before and after treatment, respectively. RESULTS: Without serum supplement, HepG2 cells expressed a small amount of survivin. Insulin induced survivin expression in a dose- and time-dependent fashion. Survivin expression was blocked if cells were pre-treated with LY294002 prior to insulin stimulation. CONCLUSION: Insulin induces survivin expression via PI3K signalling pathway, suggesting that to interfere the key gene in this signalling pathway may block survivin expression, therefore, promoting apoptosis in hepatocellular carcinoma cells.