[Inhibition effect of N-acetyl-seryl-aspartyl-lysyl-proline on myofibroblast differentiation of MRC-5 human fetal lung fibroblasts inuced by Ang II].

Objective: To explore the inhibition effect of N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP) on myofibroblast differentiation of MRC-5 human fetal lung fibroblasts induced by angiotensin (Ang) II.

Methods: The study was divided into 2 step: (1) MRC-5 human fetal lung fibroblasts was induced for 48 h at different dose of Ang II and at different time point by 100 nmol/L Ang II. Then the expression of collagen type I and α-smooth muscle actin (α-SMA) were mesaured by western blot.

[Comparative proteomic analysis on anti-fibrotic effect of N-acetyl-seryl-aspartyl-lysyl-proline in rats with silicosis].

Objective: To perform a comparative proteomic analysis for identification of pulmonary proteins related to the progression of silicosis and anti-fibrotic effect of N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP).

Methods: Bronchial instillation of SiO₂powder (for 4 or 8 weeks) was applied in rats to establish a silicosis model. Ac-SDKP treatment was performed before (prevention group) or after (treatment group) SiO₂instillation.

Ac-SDKP suppresses epithelial-mesenchymal transition in A549 cells via HSP27 signaling.

The synthetic tetrapeptide N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP) has been shown to be a modulator of molecular aspects of the fibrosis pathway. This study reveals that Ac-SDKP exerts an anti-fibrotic effect on human type II alveolar epithelial cells (A549), which are a source of myofibroblasts once exposed to TGF-β1, by decreasing the expression of heat shock protein 27 (HSP27). We used A549 cells in vitro to detect morphological evidence of epithelial-mesenchymal transition (EMT) by phase-contrast microscopy.