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Objective:To establish a mouse model of imiquimod (IMQ)-induced chronic psoriasis skin inflammation and to investigate the role of C5a/C5aR1 pathway in this process and the underlying mechanism.Methods:BALB/c mice were treated with IMQ cream or Vasline cream (control group) every other day for eight times to mimic the chronic skin inflammation. Psoriatic skin inflammation and pathological changes in the wild-type (C5aR1 + /+ ) mice and the mice with C5aR1 gene deletion (C5aR1 -/-) were monitored and analyzed. Epidermal proliferation (Ki67), keratin 6/14 expression and neutrophil infiltration in the skin lesions were observed with immunohistochemical (IHC) staining. qRCR was used to detect the expression of keratin 6/14 and related inflammatory cytokines. Flow cytometry was performed to measure the percentages of leukocytes, CD3 + T cells and IL-17A + γδTCR + T cells in local skin samples as well as IL-17A responses in draining lymph nodes. Results:IMQ treatment induced typical psoriatic skin inflammation, including scaling, erythema and thickness. Dysregulated epidermal proliferation, acanthosis, micro-abscesses, inflammatory cell infiltration and abnormal hyperplasia of dermal capillaries were observed after HE staining. Compared with the C5aR1 + /+ mice, the C5aR1 -/- mice showed significantly attenuated chronic skin inflammation, evidenced by decreased epidermal proliferation, down-regulated keratin 6/14 expression and alleviated neutrophil infiltration. Results of qPCR also indicated decreased expression of keratin 6/14, inflammatory cytokines (IFN-γ, MIP-1α, IL-1β and TNF-α) and IL-17-related cytokines (IL-6, IL-17A and IL-23) in skin samples of C5aR1 -/- mice. Moreover, the infiltration of leukocytes (CD45), CD3 + T cells and IL-17A + γδTCR + T cells in skin lesions as well as the percentages of IL-17A + , IL-17A + CD3 + T and IL-17A + γδTCR + T cells in draining lymph nodes were also decreased in C5aR1 -/- mice. Conclusions:This study suggested that IMQ treatment could induce chronic psoriasis skin inflammation in mice. C5a/C5aR1 signaling pathway mediates IMQ induced chronic skin inflammation via activating IL-17 producing cells. Targeting C5a/C5aR pathway would be a new strategy for the management of psoriasis.
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Objective To investigate the expression of autophagy and the effect of complement C5a/C5aR pathway on autophagy induced by renal ischemia reperfusion injury (IRI).Methods MaleWT and C5aR gene knockout (BALB/C background) mice were selected.The model of renal IRI was established by occluding bilateral renal pedicles with microaneurysm clamps.Mice were divided into wild type BALB/C (WT) group and C5aR gene knock out (C5aRKO) group.The pathology of kidney was assessed by HE staining.The levels of BUN and KIM-1 were detected 24 h after reperfusion.The expression of the autophagy-associated protein (LC3 Ⅱ/LC3 Ⅰ and P62) was measured by Western blotting and immunofluorescence.In vitro,human renal tubular epithelial cells (HK2) were cultured.The expression of LC3 in HK2 cells was investigated by immunofluorescence and Western blotting after being treated with recombinant C5a or C5a combined with C5aR antagonist (C5aRA).Results As compared with WT group,the severity of kidney injury was obviously reduced in C5aRKO group (P＜0.05).After ischemia-reperfusion,the expression of autophagy-related protein LC3 gradually increased with the reperfusion time prolonged.The level of autophagy induced by ischemia-reperfusion was significantly reduced in C5aRKO group as compared with WT group (P＜0.05).In addition,the expression of autophagy-related protein LC3 Ⅱ in HK2 cells was increased with the augment of C5a stimulation concentration in vitro.Blockage of C5aR pathway by C5aRA led to a significant decrease in autophagy (P ＜ 0.05).Conclusion Complement C5a/C5aR pathway promotes renal IRI-induced autophagy.
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Objective:To explore the role of TNFSF14 and its receptors LTβR and HVEM in the pathogenesis of virus hepatitis.Methods:Marine fulminant viral hepatitis model was established by infecting mice with MHV-3.Liver tissue destruction in LIGHT KO and WT mice were analyzed by HE staining and ALT levels in serum by automatic biochemical analyzer .The mRNA levels of HVEM and LTβR in the liver and spleen tissues in the indicated time points ( 0 h, 12 h, 24 h, 48 h, 72 h ) were detected by quantitative-PCR.The expression of HVEM and LTβR on PBMC in patients with severe hepatitis were measured by flow cytometry.Results:In the MHV-3-induced murine fulminant hepatitis model ,liver injury in LIGHT KO mice was obviously decreased than that of WT mice,and ALT levels was also significantly lower than that of WT mice (P<0.01).The mRNA of HVEM and LTβR in the spleen were increased significantly after 48 h postinfection with MHV-3 ( P<0.05 );The level of LTβR mRNA in liver was significantly up-regulated in 12 h postinfection with MHV-3(P<0.01).Compared to healthy volunteers,the expression of both HVEM and LTβR on PBMC in patients with severe hepatitis was remarkably enhanced .Conclusion: TNFSF14 and its receptors LTβR and HVEM play a critical role in the pathogenesis of viral fulminant hepatitis .
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Objective To investigate the expression of proinflammatory cytokine interleukin-17(IL-17) and complement cleavage fragment C5a and the regulation effect of C5a on the expression of IL-17 during renal allograft rejection .Methods The frequency of IL-17+ T cell in peripheral blood and the expression of IL-17 in renal tubular epithelial cells (HK2) after C5a stimulation in renal transplant recipients were measured by flow cytometry and the changes of serum C5a level was detected by ELISA ,respectively .Im-munohistochemistry was applied to detect and compare the expression of IL-17 and the deposition of C5b-9 in normal renal tissues and renal tissues with allograft rejection .The difference of IL-17 expression in HK2 cells before and after the recombinant C5a stimulation was detected by immunocytochemistry .Results Both the percentage of IL-17+ T cells and serum C5a levels were sig-nificantly increased after the allogeneic renal transplantation .Compared with normal renal tissues ,both the deposition of C5b-9 and the IL-17 expression in renal tissues with allograft rejection was remarkably up-regulated ,which showed the positive correlation be-tween them .The expression of IL-17 in HK2 was obviously up-regulated by the recombinant C5a stimulation .Conclusion C5a may positively regulate the expression of IL-17 by tubular epithelial cells during the renal allograft rejection .