Objective To clarify the mechanisms that the response of fibroblast-like synovial (FLS) cellsto methotrexate (MTX) in rheumatoid arthritis (RA) and to provide theory basis for the drug treatment of RA.Methods Synovial fibroblasts were isolated from synovial tissue specimens obtained from patients with RA andexposed to MTX.Cell viability was measured using a MTT assay and cell apoptosis was valued by flow cytometry.Western blotting analysis of LC3 and immunocytochemistry were used to analyze the induction of autophagy in RA-FLS after treating with MTX.Transfection of siRNA was used to interfere the expression of Beclin1 to down-regulate the autophagy,cell apoptosis was valued by flow cytometry and western blot analysis was used to test the PARPp85 with or without the presence of MTX.Statistical product and service solutions (SPSS) 18.0 statistical software was used for statistical analysis of all experimental data.Independent sample t test was used according to data distribution status,homogeneity of variance,and normal distribution.GraphPad Prism 5.0 was used to draw statistical graphs.Results MTX induced apoptosis was increased in RA-FLS.MTX stimulated the autophagy response in RA-FLS by inducing autophagosome formation.In RA-FLS,transfection with Beclin1 siRNA inhibited autophagy and increased the susceptibility to MTX,which induced cell death.Conclusion Autophagy of RA-FLS contributes to the resistance to apoptosis induced by methotrexate.

CircRNA is a single-stranded, covalently closed non-coding RNA, whose mechanism mainly involves sponge adsorption of micro RNA (miRNA), regulation of protein transcription and post-transcriptional levels, interaction with RNA-binding proteins and few coding proteins of circRNA. Meanwhile, because of its abundant expression, highly conserved and dynamic changes, circRNAs have promising applications such as becoming biomarkers of diseases, developing circRNA vaccines and gene editing therapies for circRNAs. Cardiovascular diseases are the leading cause of death from diseases worldwide, and existing therapeutic approaches can delay the development of heart diseases, but are still limited by the unknown pathogenesis and therapeutic targets. Many studies have reported the mechanistic link between circRNAs and cardiac diseases, therefore, this review is to explain the progress of circRNA research in cardiovascular diseases and to illustrate the three clinical applications in which circRNAs are currently involved.