Progressive Triad-Mitochondria Un-Coupling in Aging

Abstract

Lack of both CASQ isoforms was confirmed by western blot. The doublenull mice are viable and breed normally, however the rate of spontaneous mortality of male animals is higher than CASQ1-null animals. Whereas the overall phenotype of mice is similar to that of CASQ1-null mice, significant differences are found in Soleus. From the structural point of view, in Soleus muscle we find many fibers (about 30%) with severe structural damage that were not found in CASQ1-null animals. Functional studies indicate significant prolongation in twitch time parameters, increased twitch tension and impaired tension generation during prolonged tetani both in EDL and Soleus, likely related to abnormal calcium release kinetics. These findings suggest that: a) expression of CASQ2 is essential for the maintenance of a subpopulation of Soleus fibers; and b) lack of both CASQ1 and 2 exacerbates the overall phenotype of CASQ1null mice.

Sequential stages in the age-dependent gradual formation and accumulation of tubular aggregates in fast twitch muscle fibers: SERCA and calsequestrin involvement

“…With the exception of sarcopenia and a general decrease in CRUs (Boncompagni et al 2006;D'Incecco et al 2010), skeletal muscle fibers show few structural changes that are specifically related to aging. For that reason, TAs have attracted considerable attention because they seemed an aging phenomenon in mouse muscles, although limited almost exclusively to fast-twitch skeletal muscle fibers of males from inbred strains (Agbulut et al 2000;Chevessier et al 2004).…”