Antifibrotic effects of N-acetyl-seryl-aspartyl-lysyl-proline mediated by regulation of transforming growth factor beta and connective tissue growth factor expression on rats with silicosis / 中华劳动卫生职业病杂志

ABSTRACT

<p><b>OBJECTIVE</b>To investigate whether the effect of N-acetyl-seryl-aspartyl-lysyl-proline (AcSDKP) on transforming growth factor beta (TGF-beta1) and connective tissues growth factor (CTGF) was involved in AcSDKP's antifibrotic effect on the rats with silicosis.</p><p><b>METHODS</b>Rats were divided into 6 groups randomly, 10 rats in each group Control of silicotic model 1.0 ml normal sodium and was killed after 4 or 8 weeks; Silicotic model 1 50 mg/ml silica suspension and was killed after 4 weeks; Silicotic model 2 50 mg/ml silica suspension and was killed after 8 weeks; Anti-fibrosis treatment of AcSDKP after each rat was intratracheally instilled with 50 mg/ml silica suspension for 4 weeks, AcSDKP 800 microg/(kg x d) was administered into every rat and rats were killed at the 8 weeks; Preventing fibrosis treatment of AcSDKP after AcSDKP [800 microg/(kg x d)] was administered into every rat for 48 hours, each rat was intratracheally instilled with 50 mg/ml silica suspension and rats were killed at the 8 weeks. Lung fibrosis in morphology was observed by HE staining. The expressions of TGF-beta1 and CTGF in lung were observed by immunohistochemistry. The mRNA expressions of TGF-beta1 and CTGF in lung were observed by real-time PCR.</p><p><b>RESULTS</b>In anti-fibrosis treatment of AcSDKP group, protein expression of TGF-beta1 and CTGF were (0.244 +/- 0.016) and (0.241 +/- 0.017) respectively, and significantly lower that those in the silicotic model 1 and 2 groups; mRNA expressions of TGF-beta1 and CTGF decreased, mRNA expressions of CTGF were significantly lower that those in the silicotic model 1 and 2 groups (P < 0.05); In preventing fibrosis treatment of AcSDKP group, protein expression and mRNA expression of TGF-beta1 were significantly lower that those in the silicotic model 2 group (P < 0.05).</p><p><b>CONCLUSION</b>AcSDKP can decrease the expressions of TGF-beta1 and CTGF in lung tissues of the rats with experimentally induced pulmonary fibrosis.</p>