title: Lack of α8 integrin leads to morphological changes in renal mesangial cells, but not in vascular smooth muscle cells.
abstract: BACKGROUND
  Extracellular matrix receptors of the integrin family are known to regulate cell adhesion, shape and functions. The α8 integrin chain is expressed in glomerular mesangial cells and in vascular smooth muscle cells. Mice deficient for α8 integrin have structural alterations in glomeruli but not in renal arteries. For this reason we hypothesized that mesangial cells and vascular smooth muscle cells differ in their respective capacity to compensate for the lack of α8 integrin.
  
  
  RESULTS
  Wild type and α8 integrin-deficient mesangial cells varied markedly in cell morphology and expression or localization of cytoskeletal molecules. In α8 integrin-deficient mesangial cells α-smooth muscle actin and CTGF were downregulated. In contrast, there were no comparable differences between α8 integrin-deficient and wild type vascular smooth muscle cells. Expression patterns of integrins were altered in α8 integrin-deficient mesangial cells compared to wild type mesangial cells, displaying a prominent overexpression of α2 and α6 integrins, while expression patterns of the these integrins were not different between wild type and α8 integrin-deficient vascular smooth muscle cells, respectively. Cell proliferation was augmented in α8 integrin-deficient mesangial cells, but not in vascular smooth muscle cells, compared to wild type cells.
  
  
  CONCLUSIONS
  Our findings suggest that α8 integrin deficiency has differential effects in mesangial cells and vascular smooth muscle cells. While the phenotype of vascular smooth muscle cells lacking α8 integrin is not altered, mesangial cells lacking α8 integrin differ considerably from wild type mesangial cells which might be a consequence of compensatory changes in the expression patterns of other integrins. This could result in glomerular changes in α8 integrin-deficient mice, while the vasculature is not affected in these mice.
authors.affiliation: Hospital for Children and Adolescents, Universität Erlangen-Nürnberg, Loschgestrasse 15, 91054 Erlangen, Germany.
authors.forename: Ines
authors.initials: I
authors.lastname: Marek
authors.forename: Gudrun
authors.initials: G
authors.lastname: Volkert
authors.forename: Angelika
authors.initials: A
authors.lastname: Jahn
authors.forename: Fabian
authors.initials: F
authors.lastname: Fahlbusch
authors.forename: Christina
authors.initials: C
authors.lastname: Zürn
authors.forename: Zehra
authors.initials: Z
authors.lastname: Ozcan
authors.forename: Margarete
authors.initials: M
authors.lastname: Goppelt-Struebe
authors.forename: Karl F
authors.initials: KF
authors.lastname: Hilgers
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Rascher
authors.forename: Andrea
authors.initials: A
authors.lastname: Hartner
mesh_terms: D000818:Animals; D049109:Cell Proliferation; D002478:Cells, Cultured; D039001:Integrin alpha Chains / Q000172:deficiency* / Q000235:genetics; D050527:Mesangial Cells / Q000166:cytology* / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D009131:Muscle, Smooth, Vascular / Q000166:cytology* / Q000378:metabolism*
chemical_list: D039001:Integrin alpha Chains; C093856:integrin alpha8