P4‐3: What are the factors contributing to decreased physical activity in outpatients with respiratory diseases?

In the current study, we examined the synergistic effect of IL-17A and TNF-α to contraction of airway smooth muscle cells and its mechanism. In smooth muscles contraction assay, 12hrs incubation both with 10 ng/ml of IL-17A and 10 ng/ml of TNF-α increased ASM contractility synergistically. In western blot, the expressions of RhoA and Rock2 which are key proteins to ASM contraction were increased when ASM cells were treated with IL-17A and TNF-α. Then, we performed qRT-PCR for mRNA of RhoA and Rock2. The mRNA levels of both RhoA and Rock2 were increased when treated with 10 ng/ml of IL-17A and 10 ng/ml of TNF-α for 12 hrs. We speculated IL-17A and TNF-a synergistically stabilized mRNA and confirmed that T-half of mRNA of RhoA and Rock2 were extended when treated with the two cytokines for 1hr. This study indicates that IL-17A and TNF-α enhance ASM contraction synergistically, and suggests that the mechanism is regulation of RhoA and Rock2 mRNA stabilities.