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Th17 cells are involved in liver fibrosis by activating hepatic stellate cells (HSCs). We aimed to investigate whether HSCs are able to regulate the function of Th17 cells and to determine the relevant mechanism. Sixty-five patients diagnosed with chronic hepatitis B (CHB) were enrolled in this study. To determine the effect of HSCs on T cells, naïve CD4 + T cells and Th17 cells were sorted from CHB patients and cultured with or without activated-HSCs, and cytokine expression and gene transcription were analyzed. In addition, the regulatory mechanism of HSCs was investigated. ELISA and qRT-PCR showed that Th17 cells from CHB patients were more pathogenic, on the basis of the expression of IL-17A, IL-23R, RORC, CCL20 and CCR6, and meanwhile, they could activate the primary HSCs. Co-culture experiments indicated that activated HSCs dramatically promoted proliferation of CD4 + T cells in a time- and dose-dependent manner. In addition, they could induce naïve CD4 + T cells to become Th17 cells which had a more pathogenic phenotype. Moreover, activated HSCs-mediated induction of Th17 cells might depend on the release of IL-1β and IL-6 as well as on the COX-PGE2 pathway. Th17 cells cooperated with HSCs in a proinflammatory feedback loop might provide a better understanding of the pathogenic role of Th17 cells in the chronicity of HBV infection. [ABSTRACT FROM AUTHOR]

Selective cyclooxygenase-2 (COX-2) inhibitors have been shown to produce fewer gastrointestinal adverse reactions when compared with conventional nonselective nonsteroidal anti-inflammatory drugs and they suppress angiogenesis in tumors. The purpose of the present study was to investigate the effects of highly selective COX-2 inhibitor on angiogenesis and protein expression of angiogenic factor during gastric ulcer healing. Gastric ulcers were induced in male Sprague–Dawley rats by a luminal application of acetic acid solution. Rofecoxib, a selective COX-2 inhibitor, was administered at a dose of 10 mg/kg/day by gastric intubation for 14 successive days. The ulcer size was measured at different time intervals after ulcer induction. The microvessels that were immunohistologically positive for von Willebrand factor within the ulcer bed were counted. The protein levels of basic fibroblast growth factor (bFGF) and concentration of prostaglandin E2 (PGE2) in the ulcer tissues were analyzed with Western blotting and immunoassay methods, respectively. The results demonstrated that rofecoxib treatment significantly increased the ulcer size at days 6, 10, and 15. It decreased the number of microvessels, bFGF protein expression, and PGE2 level in the ulcer base at day 6. The findings that highly selective COX-2 inhibitor delayed ulcer healing in rats and impaired angiogenesis in the ulcer base raise cautions regarding the use of COX-2 inhibitors in patients with gastric ulcers. [Copyright &y& Elsevier]