Beta 1 integrin activation mediates adhesive differences between trisomy 21 and non-trisomic fibroblasts on type VI collagen

Ian N. Jongewaard, Ronald M. Lauer, Douglas A. Behrendt, Shivanand Patil, Scott E. Klewer

Research output: Contribution to journalArticle

22 Scopus citations

Abstract

Trisomy 21 (Down syndrome) is a common genetic condition with a high incidence of congenital heart defects (CHD), particularly those involving abnormal development of the embryonic atrioventricular (AV) canal. Type VI collagen (Col VI) is expressed in the developing AV canal extracellular matrix, and has been associated with trisomy 21 AV canal defects in human genetic studies. Although the molecular mechanisms linking Col VI and trisomy 21 AV canal defects are not well understood, a computer model predicts increased cell adhesiveness is responsible for these CHD. We compared integrin-mediated cell adhesive properties for skin fibroblasts isolated from trisomy 21 and non-trisomic individuals on Col VI, fibronectin (FN) and type I collagen (Col I). Cell lines demonstrate similar adhesion profiles to FN and Col I, but all trisomy 21 cells display increased adhesive capacity for Col VI compared to non-trisomic fibroblasts. Cell adhesion to type VI collagen was shown to be GRGDS independent, but β1integrin family dependent. Function-blocking antibodies identified α3β1 as the predominant integrin mediating trisomy 21 and nontrisomic skin fibroblast adhesion on Col VI. Trisomy 21 and non-trisomic fibroblasts display similar expression levels for each of the integrin receptors examined. A β1 integrin-activating antibody augments nontrisomic cell adhesion on Col VI, but has no effect upon trisomy 21 fibroblasts. These results demonstrate that β1 integrin family members mediate trisomy 21 and non-trisomic skin fibroblast adhesion for Col VI. Altered activation state of the β1 integrin is a mechanism responsible for increased trisomy 21 cell adhesion on Col VI.

Original languageEnglish (US)
Pages (from-to)298-305
Number of pages8
JournalAmerican journal of medical genetics
Volume109
Issue number4
DOIs
StatePublished - May 15 2002

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Keywords

  • Cell adhesion
  • Down syndrome
  • Integrin activation
  • Integrins
  • Trisomy 21
  • Type VI collagen

ASJC Scopus subject areas

  • Genetics
  • Genetics(clinical)

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