Proteomic analysis of oxymatrine-induced changes in lung fibroblasts

Oxymatrine, one kind of alkaloids extracted from Sophora flavescens Ait, has been demonstrated to attenuate bleomycin-induced lung fibrosis. The mechanisms of this action are poorly known. This study aimed to use proteomics to provide new insights into the mechanisms of the pharmacological effects. Proteins from murine lung fibroblasts exposed to oxymatrine were separated by two-dimensional electrophoresis. Differentially expressed proteins were identified using mass spectrometry. A two-dimensional cell migration assay was used to study the effects of oxymatrine on fibroblast migration activity. Among these detectable protein spots on the 2-DE gel 9 protein, spots were signii¬cantly altered in oxymatrine treated cells. 5 proteins were successfully identii¬ed. All were down-regulated by oxymatrine. Mass spectrometer analysis indicated that one of these proteins is a metabolic enzyme, while others are related to cytoskeleton or involved in cellular transcription and translation. The attenuated expressions of mRNA and protein of the cytoskeleton-related protein, HSP27, were confirmed by Western blotting and RT-PCR analysis. Besides these, the migration activity of fibroblast was reduced by oxymatrine. It is suggested that regulation of HSP27 expression by oxymatrine is associated with its inhibitory effects on motility of lung fibroblasts, which contributes to the protective action of this drug against lung fibrosis. Key words: Oxymatrine, fibroblasts, proteomics, heat shock protein 27, motility.