Effects Of IL-17F Research Articles

Effects of IL-17F/IL-17RC on the expression of caveolae-1 in rat pulmonary microvascular endothelial cells

To explore the expression of caveolin-1 (Cav-1) induced by interleukin-17F/IL-17 receptor C (IL-17F/IL-17RC) in rat pulmonary microvascular endothelial cells (PMVECs). Cultured PMVECs were divided into two groups of time-dependent experiment and IL-17RC signal pathway intervention according to the results of time-dependent experimental group: namely peak time of IL-17F-induced Cav-1 and its phosphorylation (p-Cav-1) expression of PMVEC for formulating the incubation time between IL-17F and PMVEC in IL-17RC signal pathway intervention group. Time-dependent experiment group: Western blot was used to detect the expression of Cav-1 after IL-17F stimulation for 0, 0.5, 1.5, 3.0, 6.0, 12.0, 24.0 h. Cav-1 and its phosphorylation expression after IL-17F challenge for 0, 10, 30, 60, 90, 120 min were evaluated by Western blot. IL-17RC signal pathway intervention group: PMVECs were divided into two groups after a 3-day pre-treatment of siRNA. The first group received a 60-min stimulation of 100 ng/ml IL-17F before detecting the expression of p-Cav-1 while the second group was subject to a 24-hour stimulation of 100 ng/ml IL-17F before detection. In addition, control, meaningless-siRNA, IL-17RC-siRNA, IL-17F and meaningless-siRNA + IL-17F groups were set as references for two groups respectively. IL-17F up-regulated the expression of Cav-1 in a time-dependent manner. At 0, 0.5, 1.5, 3.0, 6.0, 12.0, 24.0 h, the relative expression levels of Cav-1 were (1.139 ± 0.134), (1.276 ± 0.166), (1.604 ± 0.080), (2.115 ± 0.231), (2.763 ± 0.226), (3.309 ± 0.493) and (3.963 ± 0.169). At 1.5 h, it was significantly higher than 0 h, peaked at 24.0 h and remained significantly higher than 0, 0.5, 1.5, 3.0, 6.0, 12.0 h (all P < 0.05). And IL-17F increased the expression of p-Cav-1 in a time-dependent manner. At 0, 10, 30, 60, 90, 120 min, the relative expression levels of p-Cav-1 were (0.540 ± 0.085), (0.880 ± 0.084), (1.437 ± 0.297), (1.491 ± 0.212), (1.017 ± 0.210) and (0.882 ± 0.074). At 10 min, p-Cav-1 was significantly higher than 0 min, peaked at 60 min, remained significantly higher than 0, 10, 30, 90, 120 min (all P < 0.05) and gradually decreased. At 120 min, it was still higher than 0 min. Compared with IL-17F group, IL-17RC-siRNA significantly inhibited IL-17F-induced Cav-1 and its phosphorylation (2.126 ± 0.318 vs 3.897 ± 0.424 and 1.014 ± 0.136 vs 1.431 ± 0.298, all P < 0.05). IL-17F up-regulates the expressions of Cav-1 and p-Cav-1 in a time-dependent manner in PMVECs. And the silenced expression of IL-17RC in PMVECs by IL-17RC-siRNA significantly inhibits the IL-17F-induced expressions of Cav-1 and p-Cav-1.

Interleukin-17F Down-Regulates the Plasminogen/Plasmin Pathway in Chondrocytes

Interleukin-17 (IL-17) is a proinflammatory cytokine involved in autoimmune diseases such as rheumatoid arthritis (RA). IL-17 consists of six ligands that signal through five receptors (IL-17Rs). Serine proteinases, such as plasmin and plasminogen activators (PAs), as well as matrix metalloproteinases (MMPs) degrade the extracellular matrix during cartilage remodeling.In contrast, plasminogen activator inhibitor-1 (PAI-1), an endogenous inhibitor of PAs, forms a complex with PA to inhibit plasmin production. In the present study, we examined the effect of IL-17F on the plasminogen/plasmin pathway in cartilage using human articular chondrocytes. We evaluated the effects of IL-17F on the expression of tissue-type plasminogen activator (tPA), urokinase-type plasminogen activator (uPA), PAI-1, and cyclooxygenases (COXs), as well as on the production of prostaglandin E2 (PGE2). We also examined the indirect effects of PGE2 on the above IL-17F-induced/reduced components using NS-398, a specific inhibitor of COX-2 activity. Cells were cultured with or without IL-17F in the presence or absence of NS-398 for up to 28 days. mRNA and protein expression levels of PAs, PAI-1, and COXs were determined using real-time polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA), respectively. PGE2 production was determined by ELISA. The addition of IL-17F increased the expression of PAI-1 and COX-2, as well as the production of PGE2, whereas uPA and COX-1 expression decreased and tPA expression was unaffected. NS-398 did not block the reducing/stimulating effects of IL-17F on the expression of COX-1 and COX-2. In contrast, NS-398 may be, in part, responsible for IL-17F-induced/reduced uPA and PAI-1 expression. Our results suggest that IL-17F suppresses the plasminogen/plasmin pathway by increasing PAI-1 expression and decreasing uPA expression in chondrocytes.

IL-27 increases intestinal epithelial cell proliferation and migration and its mRNA expression is up-regulated in active Crohn's disease

Background & Aims: Interleukin (IL)-17F is a novel proinflammatory cytokine which is a member of the IL-17 cytokine family. IL-17F mediates signal transduction via the heterodimeric IL-17RA/IL-17RC receptor complex. IL-17F is closely related to IL-17A. Both cytokines are secreted by Th17 cells which play a major role in the pathogenesis of Crohn's disease (CD) and other autoimmune diseases. Previous studies demonstrated that IL-17RA, the specific receptor for IL-17A, is expressed in intestinal epithelial cells (IECs). We therefore analyzed expression, signal transduction and potential biological functions of IL-17F in IECs. Methods: Expression studies were performed by RT-PCR, Western blot analysis, and immunohistochemical analysis. IL-17F mediated signaling was analyzed in Western blot experiments. IEC restitution was analyzed by wounding assays in IEC monolayer cultures. Cell proliferation was measured in MTS assays. The effect of IL-17F on apoptosis was analyzed by flow cytometry. Results: Using RT-PCR, we demonstrated expression of IL17RA and IL-17RC in several colorectal cancer (CRC)-derived IEC lines. High IL-17RC expression was found especially in DLD-1 cells which was also confirmed by Western blot analysis and immunohistochemistry. DLD-1 cells were therefore used in the following experiments. IL-17F mediated the activation of ERK-1/2 and p38 MAP kinases and of Akt but had no significant effect on the phosphorylation levels of SAPK/JNK. IL-17F mediated signals resulted in significantly increased cell proliferation (p=0.01) and an increase of IEC restitution in wounding assays (p<0.0001). However, IL-17F had no significant effect on Fas ligand-induced apoptosis. Importantly, colonic IL-17F mRNA expression was significantly increased in inflamed colonic lesions in CD. Conclusions: Here, we demonstrate for the first time expression of the functional IL-17F receptor complex in CRC-derived IECs. IL-17F mediates similar functions as the Th17 cytokine IL-22 including up-regulation of IEC migration and proliferation suggesting tumor promoting effects in CRC. Considering that previous studies demonstrated that IL-23 promotes tumour incidence and growth (Nature 2006; 442:461-5), we propose that some of these effects may be mediated via IL-23Rexpressing Th17 cells promoting IL-17F secretion. Given the increased IL-17F expression in CD, we currently analyze whether the IL-17F receptor complex is also expressed in primary IECs modulating epithelial barrier function in intestinal inflammation.

S1721 The Selective Glucocorticoid Receptor Agonist CpdA Offers Anti-Inflammatory Action Without Affecting TGF-β Mediated Intestinal Epithelial Wound Healing

Background & Aims: Interleukin (IL)-17F is a novel proinflammatory cytokine which is a member of the IL-17 cytokine family. IL-17F mediates signal transduction via the heterodimeric IL-17RA/IL-17RC receptor complex. IL-17F is closely related to IL-17A. Both cytokines are secreted by Th17 cells which play a major role in the pathogenesis of Crohn's disease (CD) and other autoimmune diseases. Previous studies demonstrated that IL-17RA, the specific receptor for IL-17A, is expressed in intestinal epithelial cells (IECs). We therefore analyzed expression, signal transduction and potential biological functions of IL-17F in IECs. Methods: Expression studies were performed by RT-PCR, Western blot analysis, and immunohistochemical analysis. IL-17F mediated signaling was analyzed in Western blot experiments. IEC restitution was analyzed by wounding assays in IEC monolayer cultures. Cell proliferation was measured in MTS assays. The effect of IL-17F on apoptosis was analyzed by flow cytometry. Results: Using RT-PCR, we demonstrated expression of IL17RA and IL-17RC in several colorectal cancer (CRC)-derived IEC lines. High IL-17RC expression was found especially in DLD-1 cells which was also confirmed by Western blot analysis and immunohistochemistry. DLD-1 cells were therefore used in the following experiments. IL-17F mediated the activation of ERK-1/2 and p38 MAP kinases and of Akt but had no significant effect on the phosphorylation levels of SAPK/JNK. IL-17F mediated signals resulted in significantly increased cell proliferation (p=0.01) and an increase of IEC restitution in wounding assays (p<0.0001). However, IL-17F had no significant effect on Fas ligand-induced apoptosis. Importantly, colonic IL-17F mRNA expression was significantly increased in inflamed colonic lesions in CD. Conclusions: Here, we demonstrate for the first time expression of the functional IL-17F receptor complex in CRC-derived IECs. IL-17F mediates similar functions as the Th17 cytokine IL-22 including up-regulation of IEC migration and proliferation suggesting tumor promoting effects in CRC. Considering that previous studies demonstrated that IL-23 promotes tumour incidence and growth (Nature 2006; 442:461-5), we propose that some of these effects may be mediated via IL-23Rexpressing Th17 cells promoting IL-17F secretion. Given the increased IL-17F expression in CD, we currently analyze whether the IL-17F receptor complex is also expressed in primary IECs modulating epithelial barrier function in intestinal inflammation.