Objective: To explore the effects of tumor necrosis factor-alpha (TNF-α) or methylprednisolone on the expression of interleukin-17 receptor C (IL-17RC) in rat pulmonary microvascular endothelial cells (RPMVEC).
Methods: Culture RPMVEC were randomly divided into dose-dependent and time-dependent groups. In dose-dependent group, cells were cultured with TNF-α (0, 0.1, 1, 10 µg/L TNF-α) for 3 h. In time-dependent group, cells were cultured with TNF-α (10 µg/L) for 0, 1, 3, 6, 12 h. In the drug intervention group, cells were cultured with TNF-α (10 µg/L) or methylprednisolone (200 µg/L) +TNF-α (10 µg/L) for 3 h respectively. The expression of IL-17RC in isolated and cultured RPMVEC was identified by reverse transcription-polymerase chain reaction (RT-PCR), Western blot and immunocytochemistry. The changes of IL-17RC mRNA were detected by RT-PCR after the stimulation of RPMVEC by TNF-α or methylprednisolone.
Results: RT-PCR and Western blot revealed that IL-17RC mRNA and protein were present in RPMVEC. The product of IL-17RC immunocytochemical reaction was predominantly located in cytoplasm and cytomembrane. In RPMVEC TNF-α significantly up-regulated IL-17RC mRNA in a dose-dependent manner (0 µg/L TNF-α group: 0.241 ± 0.010, 0.1 µg/L TNF-α group: 0.372 ± 0.017, 1 µg/L TNF-α group: 0.452 ± 0.017, 10 µg/L TNF-α group: 0.643 ± 0.042, F = 33.774, P < 0.05). In time-dependent group, the expression of IL-17RC mRNA rose at 1 h (0.417 ± 0.038), peaked at 3 h (0.674 ± 0.018), then decreased gradually at 6 h (0.378 ± 0.035), but stayed higher at 12 h (0.318 ± 0.032). When compared with 0 h group (0.197 ± 0.008), there were significant differences (F = 37.903, P < 0.05). Methylprednisolone caused a marked attenuation of TNF-α-induced IL-17RC expression (0.333 ± 0.031 vs 0.660 ± 0.026, F = 89.637, P < 0.05).
Conclusions: IL-17RC is predominantly present in cytomembrane and cytoplasm of RPMVEC. TNF-α up-regulates the expression of IL-17RC mRNA. Methylprednisolone inhibits the elevated expression of IL-17RC mRNA induced by TNF-α so as to relieve the inflammatory response of PMVEC.