Age-related DGC structure and function in the F344/N X BN rat heart

Recent data has suggested that disruption of the dystrophin-glycoprotein complex (DGC) may be involved in mediating the progression of cardiac hypertrophy and failure. Here we examined the regulation of DGC proteins in the hearts of adult (6 months), aged (30 months), and very aged (36 months) F344/N X BN rats. Compared to adult animals, the content of alpha- and beta-dystroglycan were 6.93 +/- 5.16% and 58.36 +/- 3.64% higher, respectively (P < 0.05) in very aged animals. Immunoblotting and immunhistochemical analysis suggested that aging appeared to diminish alpha-sarcoglycan, beta-sarcoglycan and delta-sarcoglycan content by 13.89 +/- 3.1%,15.8 +/- 2.8% and 18.63 +/- 3.04%, respectively (P < 0.05). These alterations in the DGC occurred coincident with age-associated alterations in cytoplasmic anti-rat IgG immunoreactivity, TUNEL positive nuclei, alpha-fodrin cleavage, indices of caspase-3 activation and diminished AKT phosphoryation (Ser 308). Taken together, these data suggest that aging alters cardiac DGC structure and function.; Keywords. aging; heart; dystrophin glycoprotein complex; apoptosis; cell signaling...