The Role Of IGFBP2 Through ERK1/2 Signal Pathways Regulating The RA-FLS Cell Biology Behavior

OBJECTIVES: In order to study the role of insulin-like growth factor binding protein 2(IGFBP2)in rheumatoid arthritis synovial fibroblasts(RA-FLS)biological behavior and the role of IGFBP2 for Extracellular regulated protein kinases1/2,ERK1/2.METHODS: Firstly,we cultured RA-FLS and FLS normal cells using primary culture assay.then q RT PCR,Western blot and immunofluorescence assays were performed to detect the m RNA and protein expression levels of IGFBP2 in fibroblast-like synoviosytes(FLS)and fibroblast-like synoviosytes from rheumatoid arthritis patients(RA-FLS).Secondly,RA-FLS cells were transfected with si RNA-IGFBP2 and si RNA-NC,q RT-PCR was used to detect the m RNA expression level of IGFBP2 in RA-FLS cells.CCK 8 assay was perforemed to measure the effect of IGFBP2 interference on on RAFLS cell proliferation ability;Flow cytometry was used to detect the effect of IGFBP2 interference on RA-FLS cell apoptosis;Transwell analyzed the effect of IGFBP2 interference on RA-FLS cell invision ability;Wound healing assay analyzed the influence of IGFBP2 interference on RA-FLS cell migration ability.In addition,the RA-FLS cells were transfected with IGFBP2 si RNAs after 48 hrs,total RNA and total protein were extracred,q RT-PCR and Western blot assays were used to analyze the expression levels of IGFBP2,ERK and p-ERK in RA-FLS cells.RESULTS: The expression of IGFBP2 in FLS cells and RA-FLS cells:The results of q RT-PCR and western blot showed that the m RNA and protein expression of IGFBP2 remarkably increased in RA-FLS cells when compared with FLS cells;After down-regulate the IGFBP2 expression:Significantly decrease IGFBP2 expression which was determined by q RT-PCR,exogenous inhibition of IGFBP2 could inhibit the proliferation and invasion and migration of RA-FLS cells by CCK-8 assay and transwell test and cell scratch assay respectively,We also found RA-FLS cells transfected with IGFBP2 si RNA had a significant higher rate of apoptosis by flow cytometry.The phosphor-ERK1/2 expression was downregulated by IGFBP2 si RNA,and no significant changes were observed in total-ERK1/2.CONCLUSIONS: In summary,IGFBP2 showed a higher m RNA and protein expression level in RA-FLS than that in FLS.Silencing IGFBP2 was shown to decrease proliferation,invasion,migration and increase apoptosis via ERK signaling pathway in RA-FLS.Therefore,silencing IGFBP2 levers may represent a new targeted therapy for the treatment of rheumatoid arthritis.