- Ferrandi, Mara;
- Cusi, Daniele;
- Molinari, Isabella;
- Del Vecchio, Lucia;
- Barlassina, Cristina;
- Rastaldi, Maria Pia;
- Schena, Francesco Paolo;
- Macciardi, Fabio;
- Marcantoni, Carmelita;
- Roccatello, Dario;
- Peters, Luanne L;
- Armelloni, Silvia;
- Min, Li;
- Giardino, Laura;
- Mattinzoli, Deborah;
- Camisasca, Claudio;
- Palazzo, Fiorentina;
- Manunta, Paolo;
- Ferrari, Patrizia;
- Bianchi, Giuseppe
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.