Effects of IL-32γ on proliferation and cell cycle of rat vascular smooth muscle cells

AIM: To observe the effects of interleukin-32γ(IL-32γ)on the proliferation and cell cycle of rat vascular smooth muscle cells(VSMCs).METHODS: The VSMCs were isolated from the thoracic aorta of SD rats by the method of tissue-piece inoculation.The cells were cultured and treated with different concentrations of IL-32γ.The proliferation of the cells was examined by MTT assay.The cell cycles were analyzed by flow cytometry.The protein levels of NF-κB p65 and cyclin D1 were detected by Western blotting.The expression of proliferating cell nuclear antigen(PCNA)was examined by immunocytochemical staining.RESULTS: Administration of IL-32γ at the concentrations of 10~50 μg/L for 24～48 h significantly promoted the proliferation of VSMCs in a dose-and time-dependent manner.After stimulation with IL-32γ at the concentration of 50 μg/L for 24 h,the cell cycle transition from G1 phase to S/G2 phase was accelerated and the expression levels of NF-κB p65,cyclin D1 and PCNA increased as compared with those in control group.CONCLUSION: IL-32γ promotes the proliferation of rat VSMCs and accelerates the cell cycle transition via upregulating the expression of NF-κB p65 and cyclin D1.