alpha- and beta-Adducin polymorphisms affect podocyte proteins and proteinuria in rodents and decline of renal function in human IgA nephropathy

J Mol Med (Berl). 2010 Feb;88(2):203-17. doi: 10.1007/s00109-009-0549-x. Epub 2009 Oct 17.

Abstract

Adducins are cytoskeletal actin-binding proteins (alpha, beta, gamma) that function as heterodimers and heterotetramers and are encoded by distinct genes. Experimental and clinical evidence implicates alpha- and beta-adducin variants in hypertension and renal dysfunction. Here, we have addressed the role of alpha- and beta-adducin on glomerular function and disease using beta-adducin null mice, congenic substrains for alpha- and beta-adducin from the Milan hypertensive (MHS) and Milan normotensive (MNS) rats and patients with IgA nephropathy. Targeted deletion of beta-adducin in mice reduced urinary protein excretion, preceded by an increase of podocyte protein expression (phospho-nephrin, synaptopodin, alpha-actinin, ZO-1, Fyn). The introgression of polymorphic MHS beta-adducin locus into MNS (Add2, 529R) rats was associated with an early reduction of podocyte protein expression (nephrin, synaptopodin, alpha-actinin, ZO-1, podocin, Fyn), followed by severe glomerular and interstitial lesions and increased urinary protein excretion. These alterations were markedly attenuated when the polymorphic MHS alpha-adducin locus was also present (Add1, 316Y). In patients with IgA nephropathy, the rate of decline of renal function over time was associated to polymorphic beta-adducin (ADD2, 1797T, rs4984) with a significant interaction with alpha-adducin (ADD1, 460W, rs4961). These findings suggest that adducin genetic variants participate in the development of glomerular lesions by modulating the expression of specific podocyte proteins.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Calmodulin-Binding Proteins / genetics*
  • Calmodulin-Binding Proteins / metabolism
  • Glomerulonephritis, IGA / genetics*
  • Glomerulonephritis, IGA / pathology
  • Humans
  • Kidney / metabolism
  • Kidney / pathology
  • Kidney Function Tests
  • Mice
  • Podocytes* / metabolism
  • Podocytes* / pathology
  • Polymorphism, Genetic*
  • Proteinuria / genetics*
  • Rats
  • Rodentia

Substances

  • Calmodulin-Binding Proteins
  • adducin