Format

Send to

Choose Destination
J Clin Invest. 2003 Jun;111(11):1683-90.

Mice deficient in alpha-actinin-4 have severe glomerular disease.

Author information

1
Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA.

Abstract

Dominantly inherited mutations in ACTN4, which encodes alpha-actinin-4, cause a form of human focal and segmental glomerulosclerosis (FSGS). By homologous recombination in ES cells, we developed a mouse model deficient in Actn4. Mice homozygous for the targeted allele have no detectable alpha-actinin-4 protein expression. The number of homozygous mice observed was lower than expected under mendelian inheritance. Surviving mice homozygous for the targeted allele show progressive proteinuria, glomerular disease, and typically death by several months of age. Light microscopic analysis shows extensive glomerular disease and proteinaceous casts. Electron microscopic examination shows focal areas of podocyte foot-process effacement in young mice, and diffuse effacement and globally disrupted podocyte morphology in older mice. Despite the widespread distribution of alpha-actinin-4, histologic examination of mice showed abnormalities only in the kidneys. In contrast to the dominantly inherited human form of ACTN4-associated FSGS, here we show that the absence of alpha-actinin-4 causes a recessive form of disease in mice. Cell motility, as measured by lymphocyte chemotaxis assays, was increased in the absence of alpha-actinin-4. We conclude that alpha-actinin-4 is required for normal glomerular function. We further conclude that the nonsarcomeric forms of alpha-actinin (alpha-actinin-1 and alpha-actinin-4) are not functionally redundant. In addition, these genetic studies demonstrate that the nonsarcomeric alpha-actinin-4 is involved in the regulation of cell movement.

PMID:
12782671
PMCID:
PMC156110
DOI:
10.1172/JCI17988
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for American Society for Clinical Investigation Icon for PubMed Central
Loading ...
Support Center