Lifelong maintenance of composition, function and cellular/subcellular distribution of proteasomes in human liver

Publication date: November–December 2014 Source:Mechanisms of Ageing and Development, Volumes 141–142 Author(s): Elena Bellavista , Morena Martucci , Francesco Vasuri , Aurelia Santoro , Michele Mishto , Alexander Kloss , Elisa Capizzi , Alessio Degiovanni , Catia Lanzarini , Daniel Remondini , Alessandro Dazzi , Sara Pellegrini , Matteo Cescon , Miriam Capri , Stefano Salvioli , Antonia D’Errico-Grigioni , Burkhardt Dahlmann , Gian Luca Grazi , Claudio Franceschi Owing to organ shortage, livers from old donors are increasingly used for transplantation. The function and duration of such transplanted livers are apparently comparable to those from young donors, suggesting that, despite some morphological and structural age-related changes, no major functional changes do occur in liver with age. We tested this hypothesis by performing a comprehensive study on proteasomes, major cell organelles responsible for proteostasis, in liver biopsies from heart-beating donors. Oxidized and poly-ubiquitin conjugated proteins did not accumulate with age and the three major proteasome proteolytic activities were similar in livers from young and old donors. Analysis of proteasomes composition showed an age-related increased of β5i/α4 ratio, suggesting a shift toward proteasomes containing inducible subunits and a decreased content of PA28α subunit, mainly in the cytosol of hepatocytes. Thus our data suggest that, proteasomes activity is well preserved in livers...
Source: Mechanisms of Ageing and Development - Category: Geriatrics Source Type: research