Affiliation:
1. Department of Medicine, Division of Nephrology, Mount Sinai School of Medicine, New York, New York; and
2. Department of Pediatrics, Children's Research Institute, Medical College of Wisconsin, Milwaukee, Wisconsin
Abstract
Integrin-associated focal adhesion complex formation and turnover plays an essential role in directing interactions between epithelial cells and the extracellular matrix during organogenesis, leading to appropriate cell spreading, cell-matrix adhesion, and migration. Autosomal recessive polycystic kidney disease (ARPKD) is associated with loss of function of PKHD1-encoded protein fibrocystin-1 and is characterized by cystic dilation of renal collecting tubules (CT) in utero and loss of renal function in patients if they survive the perinatal period. Normal polycystin-1 (PC-1)/focal adhesion complex function is required for control of CT diameter during renal development, and abnormalities in these complexes have been demonstrated in human PC-1 mutant cystic cells. To determine whether loss of fibrocystin-1 was associated with focal adhesion abnormalities, ARPKD cells or normal age-matched human fetal (HF)CT cells in which fibrocystin-1 had been decreased by 85% by small interfering RNA inhibition were compared with normal HFCT. Accelerated attachment and spreading on collagen matrix and decreased motility of fibrocystin-1-deficient cells were associated with longer paxillin-containing focal adhesions, more complex actin-cytoskeletal rearrangements, and increased levels of total β1-integrin, c-Src, and paxillin. Immunoblot analysis of adhesive cells using site-specific phospho-antibodies demonstrated ARPKD-associated loss of activation of focal adhesion kinase (FAK) by phosphorylation at its autophosphorylation site (Y397); accelerated FAK inhibition by phosphorylation at Y407, S843, and S910; as well as increased activation of c-Src at pY418. Paxillin coimmunoprecipitation analyses suggested that fibrocystin-1 was a component of the normal focal adhesion complex and that actin and fibrocystin-1 were lost from ARPKD complexes.
Publisher
American Physiological Society
Cited by
32 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献