[Effect of N-acetyl-seryl-aspartyl-lysyl-proline on differentiation from pulmonary fibroblast to myofibroblast mediated by Rho-associated coiled-coil forming protein kinase pathway].
OBJECTIVE
To investigate whether N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP) can inhibit the differentiation of pulmonary fibroblasts into myofibroblasts by regulating Rho-associated coiled-coil forming protein kinase (ROCK) pathway mediated by transforming growth factor-β1 (TGF-β1).


METHODS
Primary culture of pulmonary fibroblasts was performed by trypsinization method. Four generations of pulmonary fibroblasts were divided into control group, TGF-β-induced differentiation group, Y-27632 treatment group, and Ac-SDKP treatment group. The intracellular distributions of ROCK, serum response factor (SRF), and α-smooth muscle actin (α-SMA) were observed by confocal laser scanning microscopy. The protein expression of ROCK, SFR, α-SMA, and type I and type III collagen in pulmonary fibroblasts was measured by Western blot. The mRNA expression of ROCK, SFR, and α-SMA was measured by real-time quantitative PCR.


RESULTS
Compared with the control group, the pulmonary fibroblasts stimulated by TGF-β1 had a lot of α-SMA antibody-labeled myofilaments in parallel or cross arrangement, as observed by confocal laser scanning microscopy, and the mRNA and protein expression of ROCK, SRF, and α-SMA and protein expression of type I and type III collagen increased significantly after 6, 12, and 24 h of stimulation (P < 0.05). Compared with the TGF-β1-induced differentiation group, the Y-27632 treatment group and Ac-SDKP treatment group had significantly decreased mRNA and protein expression of ROCK, SRF, and α-SMA and protein expression of type I and type III collagen at the same time point (P < 0.05).


CONCLUSIONS
Ac-SDKP can inhibit the differentiation of pulmonary fibroblasts into myofibroblasts and the synthesis of collagen in rats by regulating the ROCK pathway mediated by TGF-β1. That may be one of the mechanisms by which Ac-SDKP acts against (silicotic) pulmonary fibrosis.
Hebei United University, Tangshan, Hebei Province 063000, China.
Yuan
Y
Yuan
Fang
F
Yang
Hong
H
Xu
Wan-ying
WY
Yu
Yue
Y
Sun
Hai-jing
HJ
Deng
Wen-dong
WD
Ma
Zhong-qiu
ZQ
Wei
Rui-min
RM
Wang
D000199:Actins / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn; D002454:Cell Differentiation / Q000187:drug effects*; D002478:Cells, Cultured; D024042:Collagen Type I / Q000378:metabolism; D024061:Collagen Type III / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology* / Q000187:drug effects; D008168:Lung / Q000166:cytology / Q000187:drug effects; D058628:Myofibroblasts / Q000166:cytology* / Q000187:drug effects; D009842:Oligopeptides / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D026362:Serum Response Factor / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000494:pharmacology; D054460:rho-Associated Kinases / Q000378:metabolism
D000199:Actins; D024042:Collagen Type I; D024061:Collagen Type III; D009842:Oligopeptides; D026362:Serum Response Factor; D016212:Transforming Growth Factor beta; D054460:rho-Associated Kinases; C498862:Acta2 protein, rat; C058504:goralatide