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

Objective: 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).

Methods: 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.

Results: 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).

Conclusions: 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.