ABSTRACT
Background Studies showed that macophenolic acid (MPA)down-regulates and inhibits the expression and secretion of tissue growth factor and inflammatory factor,and further impacts the proliferation and inflammation process.Pterygium is an inflammatory and proliferative lesion.Whether MPA has an inhibitory effect on pterygium is unclear.Objective This study was to investigate the antifibrotic effects of macophenolic acid on pterygium fibroblasts(PFBs) in vitro and discuss its mechanism.Methods Pterygium tissue was obtained from pterygium patient during the surgery.PFBs were cultured using explants and identified with vimentin immunohistochemisty.0,0.125,0.250,0.500,1.000 μmol/L MPA were added into the culture medium,respectively,and the cells were cultured in the medium without MPA as the control group.MTT colorimetry was used to find the optimization effective concentration of MPA and evaluate their inhibitory effect on PFBs,and BrdU fluorescence staining was used to assess the growth statue of PFBs.Expressions of nuclear factor-κB(NF-κB),p65 and inhibitor of NF-κB-α(IκB-α) in the cells were detected by Western blot.Results The cells was spindle in shape 3 days after cultured and showed the vortex and radial arrangement with the positive response to vimentin.With the increase of MPA,the proliferative value of PFBs (A560)showed gradually decline,with a significant difference among the five groups (F =42.874,P＜0.01).In addition,the proliferative value of PFBs (A560) significantly lowed as the prolong of MPA active time(F=26.038,P＜0.01).BrdU fluorescence staining showed a significant decrease of DNA synthesis of PFBs with the elevation of MPA dose among the five groups(F=175.279,P＜0.05),and the A560of PFBs DNA synthesis in different concentrations of MPA groups was lower than that of the control group (all at P＜0.05).No apoptotic and necrotic cell was found after MPA action by DAPI staining.The expression level of p65 in the PFBs was 0.886±0.072 and 1.542±0.124 in the MPA group and the control group,indicating a declined value in the MPA group(P＜0.05).However,the expression value of IκB-α in the cytoplasm PFBs was significantly higher in the MPA group compared with the control group(2.141 ±0.305 vs.1.559±0.267) (P＜0.05).Conclusions MPA has an inhibitory effect on the growth of PFBs,which probably is related to the arresting of NF-κB pathway.