La pseudomiotonia congenita del bovino come modello sperimentale per lo studio della malattia umana di Brody

Brody disease is a rare inherited disorder of skeletal muscle due to a sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA) deficiency, resulting from a defect of ATP2A1 gene coding for SERCA1 isoform. The SERCA1 isoform, expressed in fast-twitch (type 2) skeletal muscle fibers, is a key participant in the Ca2+ homeostasis, being responsible for the transport of Ca2+ from cytosol to sarcoplasmic reticulum lumen. Recently, an inherited muscle disorder defined as “congenital pseudomyotonia” has been described in Chianina cattle and in a Dutch Improved Red and With cross-breed calf. Cattle pseudomyotonia has been well characterized at both genetic and biochemical levels. By DNA sequencing of affected calves, we have provided evidence of mutations in ATP2A1 gene. Moreover, our results clearly demonstrate that cattle pathological muscles are characterized by a selective deficiency in Ca2+-ATPase activity. Recently, we have obtained crystals of bovine SERCA1 protein. On the basis of symptoms and of genetic and biochemical confirmations, cattle pseudomyotonia has been defined as the true counterpart of human Brody disease and bovine species represents a suitable non-conventional animal model for investigating the pathogenesis of Brody disease.