Patsenker Eleonora, Popov Yury, Wiesner Matthias, Goodman Simon L, Schuppan Detlef
Institute of Clinical Pharmacology, University of Bern, Bern, Switzerland.
J Hepatol. 2007 May;46(5):878-87. doi: 10.1016/j.jhep.2006.11.011. Epub 2006 Dec 12.
BACKGROUND/AIMS: Activated hepatic stellate cells (HSC) play a central role in the development of liver fibrosis. Platelet-derived growth factor (PDGF)-BB and the integrin alphavbeta3 mediate mesenchymal cell migration and proliferation. However, their contribution and interaction during fibrogenic activation of HSC remains unclear. To this aim we investigated if PDFGF-BB and alphavbeta3 interact, and how far small molecular inhibitors of alphavbeta3 modulate PDGF-BB and serum-induced migration, proliferation and fibrogenic activation of HSC.
Rat and human HSC were subjected to migration and proliferation assays in the presence or absence of a peptide or a nonpeptide alphavbeta3 inhibitor. Activation of mitogen-activated protein kinases (ERK1/2, p38), Akt, focal adhesion kinase (FAK), paxillin and beta3 integrin was evaluated by phospho-specific Western blotting. Fibrosis related transcripts were determined by quantitative real-time PCR.
PDGF-BB-stimulated HSC migration which was blocked dose-dependently by the alphavbeta3 antagonists, with complete inhibition at 10(-6)M. alphavbeta3 blockage did not affect cell viability or proliferation, while it decreased phosphorylation of FAK, paxillin, beta3 integrin and p38, but not of ERK1/2 or Akt. alphavbeta3 inhibition led to downregulation of certain profibrogenic transcripts, while it upregulated fibrolytic MMP-13 mRNA.
Inhibition of integrin alphavbeta3 leads to abrogation of migration of HSC stimulated with PDGF-BB and to an antifibrogenic gene expression pattern.
背景/目的：活化的肝星状细胞（HSC）在肝纤维化发展过程中起核心作用。血小板衍生生长因子（PDGF）-BB和整合素αvβ3介导间充质细胞迁移和增殖。然而，它们在HSC纤维化激活过程中的作用及相互作用仍不清楚。为此，我们研究了PDGF-BB与αvβ3是否相互作用，以及αvβ3小分子抑制剂在多大程度上调节PDGF-BB和血清诱导的HSC迁移、增殖及纤维化激活。
在有或无肽类或非肽类αvβ3抑制剂存在的情况下，对大鼠和人HSC进行迁移和增殖试验。通过磷酸化特异性蛋白质印迹法评估丝裂原活化蛋白激酶（ERK1/2、p38）、Akt、粘着斑激酶（FAK）、桩蛋白和β3整合素的激活情况。通过定量实时PCR测定纤维化相关转录本。
PDGF-BB刺激HSC迁移，αvβ3拮抗剂可剂量依赖性地阻断该迁移，在10^(-6)M时完全抑制。αvβ3阻断不影响细胞活力或增殖，但可降低FAK、桩蛋白、β3整合素和p38的磷酸化水平，而不影响ERK1/2或Akt的磷酸化水平。αvβ3抑制导致某些促纤维化转录本下调，同时上调纤溶酶原激活物MMP-13 mRNA。
整合素αvβ3的抑制导致PDGF-BB刺激的HSC迁移被消除，并导致抗纤维化基因表达模式。
