Aspects of the renal phenotype of adult alpha8 integrin-deficient mice.

Integrins mediate cell-matrix interactions which are important for organ development. In the kidney, alpha8 integrin is expressed during early nephrogenesis. In alpha8 gene-mutated mice, lack of alpha8 leads to unilateral or bilateral renal agenesis in part of the animals. We investigated surviving animals with one or two kidneys. These mice had significantly reduced renal mass and displayed higher blood pressure compared with the wild-type. Furthermore, most of them revealed urine concentration defects. Many alpha8-deficient mice also exhibited segmental malformations of the kidney with collapse or atrophy of tubuli and interstitial cell infiltrates. These data provide further evidence that alpha8 has important functions in renal development.