Effect of ageing on the expression of protein kinase C and its activation by 1,25(OH)(2)-vitamin D-3 in rat skeletal muscle

FACCHINETTI MM; DE BOLAND AR

CELLULAR SIGNALLING

ELSEVIER SCIENCE INC

Lugar: New York; Año: 1999 vol. 11 p. 39 - 44

0898-6568

To characterize age-induced effects on muscle protein kinase C (PKC) and its regulation by the steroid hormone 1,25(OH)2-vitamin D3 [1,25(OH)2D3], changes in PKC activity and the expression and translocation of the specific PKC conventional isoforms a and b, novel isoforms d, e, and u and atypical isoform z were studied in homogenates and subcellular fractions from skeletal muscle of young (3 months) and aged (24 months) rats treated in vitro with 1,25(OH)2D3. The hormone (1029 M) increased total and membrane PKC activity, within 1 min, and these effects were completely blunted in muscle from aged rats. The presence of PKC isoenzymes was shown by Western blot analysis with the use of specific antibodies. The expression of PKC a, b and2-vitamin D3 [1,25(OH)2D3], changes in PKC activity and the expression and translocation of the specific PKC conventional isoforms a and b, novel isoforms d, e, and u and atypical isoform z were studied in homogenates and subcellular fractions from skeletal muscle of young (3 months) and aged (24 months) rats treated in vitro with 1,25(OH)2D3. The hormone (1029 M) increased total and membrane PKC activity, within 1 min, and these effects were completely blunted in muscle from aged rats. The presence of PKC isoenzymes was shown by Western blot analysis with the use of specific antibodies. The expression of PKC a, b anda and b, novel isoforms d, e, and u and atypical isoform z were studied in homogenates and subcellular fractions from skeletal muscle of young (3 months) and aged (24 months) rats treated in vitro with 1,25(OH)2D3. The hormone (1029 M) increased total and membrane PKC activity, within 1 min, and these effects were completely blunted in muscle from aged rats. The presence of PKC isoenzymes was shown by Western blot analysis with the use of specific antibodies. The expression of PKC a, b andin vitro with 1,25(OH)2D3. The hormone (1029 M) increased total and membrane PKC activity, within 1 min, and these effects were completely blunted in muscle from aged rats. The presence of PKC isoenzymes was shown by Western blot analysis with the use of specific antibodies. The expression of PKC a, b anda, b and d was greatly diminished in old rats, whereas age-related changes were less pronounced in the isoforms e, u andwas greatly diminished in old rats, whereas age-related changes were less pronounced in the isoforms e, u and z. After a short exposure (1 min) of muscle to 1,25(OH)2D3, increased amounts of PKC a and b in muscle membranes and reverse translocation (from membrane to cytosol) of PKC e were observed only in young animals. The data indicate that, in rat muscle, ageing impairs calcium-dependent PKC (a and b) and calcium-independent PKC (d, e, u and z) signal transduction pathways under selective regulation by 1,25(OH)2D3.. After a short exposure (1 min) of muscle to 1,25(OH)2D3, increased amounts of PKC a and b in muscle membranes and reverse translocation (from membrane to cytosol) of PKC e were observed only in young animals. The data indicate that, in rat muscle, ageing impairs calcium-dependent PKC (a and b) and calcium-independent PKC (d, e, u and z) signal transduction pathways under selective regulation by 1,25(OH)2D3.e were observed only in young animals. The data indicate that, in rat muscle, ageing impairs calcium-dependent PKC (a and b) and calcium-independent PKC (d, e, u and z) signal transduction pathways under selective regulation by 1,25(OH)2D3.a and b) and calcium-independent PKC (d, e, u and z) signal transduction pathways under selective regulation by 1,25(OH)2D3.d, e, u and z) signal transduction pathways under selective regulation by 1,25(OH)2D3.