BACKGROUND/AIMS: Injury and activation of tubular proximal epithelial cells (TEC) play central roles in renal tubulointerstitial fibrosis (TIF), but its mechanisms remain obscure. Interleukin 18 (IL-18) is overproduced during chronic kidney diseases (CKD), but how IL-18 affects the biological behaviour of TEC is not clear. The aim of the present study is to reveal the role of IL-18 in renal TIF. METHODS: The expressions of IL-18 and IL-18 receptor in TEC were detected by immunohistochemical staining in vivo and by reverse transcriptase polymerase chain reaction (RT-PCR) in vitro. TEC line (HK-2 cells) were incubated without or with IL-18. Cell proliferation and cell cycle were evaluated by methyl thiazolyl tetrazolium assay and flow cytometric analysis, respectively. Cell apoptosis was assessed by Hoechst 33258 staining. Expression of alpha-smooth muscle actin was evaluated by RT-PCR, immunocytochemical staining and flow cytometric analysis, respectively. Type I collagen, fibronectin, MCP-1 and RANTES in cultured supernatants were measured by enzyme-linked immunosorbent assay. RESULTS: IL-18 expression in TEC increased significantly in CKD state. IL-18 receptor was constitutively expressed in normal proximal TEC, and its expression increased strongly in CKD state. Proliferation and cell cycle of HK-2 cells were not affected by IL-18. Cell apoptosis, alpha-smooth muscle actin expression, type I collagen and fibronectin production as well as MCP-1 secretion were promoted by IL-18 in dosage- and/or time-dependent manners, but RANTES secretion was not affected. CONCLUSION: IL-18 may play a crucial role in the process of TIF by promoting TEC injury and activation, and could be a target of the therapeutic approaches against TIF.
BACKGROUND/AIMS: Injury and activation of tubular proximal epithelial cells (TEC) play central roles in renal tubulointerstitial fibrosis (TIF), but its mechanisms remain obscure. Interleukin 18 (IL-18) is overproduced during chronic kidney diseases (CKD), but how IL-18 affects the biological behaviour of TEC is not clear. The aim of the present study is to reveal the role of IL-18 in renal TIF. METHODS: The expressions of IL-18 and IL-18 receptor in TEC were detected by immunohistochemical staining in vivo and by reverse transcriptase polymerase chain reaction (RT-PCR) in vitro. TEC line (HK-2 cells) were incubated without or with IL-18. Cell proliferation and cell cycle were evaluated by methyl thiazolyl tetrazolium assay and flow cytometric analysis, respectively. Cell apoptosis was assessed by Hoechst 33258 staining. Expression of alpha-smooth muscle actin was evaluated by RT-PCR, immunocytochemical staining and flow cytometric analysis, respectively. Type I collagen, fibronectin, MCP-1 and RANTES in cultured supernatants were measured by enzyme-linked immunosorbent assay. RESULTS:IL-18 expression in TEC increased significantly in CKD state. IL-18 receptor was constitutively expressed in normal proximal TEC, and its expression increased strongly in CKD state. Proliferation and cell cycle of HK-2 cells were not affected by IL-18. Cell apoptosis, alpha-smooth muscle actin expression, type I collagen and fibronectin production as well as MCP-1 secretion were promoted by IL-18 in dosage- and/or time-dependent manners, but RANTES secretion was not affected. CONCLUSION:IL-18 may play a crucial role in the process of TIF by promoting TEC injury and activation, and could be a target of the therapeutic approaches against TIF.
Authors: Hongji Zhang; Karen L Hile; Hiroshi Asanuma; Brian Vanderbrink; Ethan I Franke; Matthew T Campbell; Kirstan K Meldrum Journal: Am J Physiol Renal Physiol Date: 2011-04-20
Authors: Markus Reichold; Enriko D Klootwijk; Joerg Reinders; Edgar A Otto; Mario Milani; Carsten Broeker; Chris Laing; Julia Wiesner; Sulochana Devi; Weibin Zhou; Roland Schmitt; Ines Tegtmeier; Christina Sterner; Hannes Doellerer; Kathrin Renner; Peter J Oefner; Katja Dettmer; Johann M Simbuerger; Ralph Witzgall; Horia C Stanescu; Simona Dumitriu; Daniela Iancu; Vaksha Patel; Monika Mozere; Mehmet Tekman; Graciana Jaureguiberry; Naomi Issler; Anne Kesselheim; Stephen B Walsh; Daniel P Gale; Alexander J Howie; Joana R Martins; Andrew M Hall; Michael Kasgharian; Kevin O'Brien; Carlos R Ferreira; Paldeep S Atwal; Mahim Jain; Alexander Hammers; Geoffrey Charles-Edwards; Chi-Un Choe; Dirk Isbrandt; Alberto Cebrian-Serrano; Ben Davies; Richard N Sandford; Christopher Pugh; David S Konecki; Sue Povey; Detlef Bockenhauer; Uta Lichter-Konecki; William A Gahl; Robert J Unwin; Richard Warth; Robert Kleta Journal: J Am Soc Nephrol Date: 2018-04-13 Impact factor: 10.121
Authors: Brian A VanderBrink; Hiroshi Asanuma; Karen Hile; Honji Zhang; Richard C Rink; Kirstan K Meldrum Journal: J Urol Date: 2011-08-19 Impact factor: 7.450
Authors: Ethan I Franke; Brian A Vanderbrink; Karen L Hile; Hongji Zhang; Alexandra Cain; Futoshi Matsui; Kirstan K Meldrum Journal: PLoS One Date: 2012-10-12 Impact factor: 3.240