Differential expression of the alpha- and beta-isoforms of protein kinase C in peripheral blood T and B cells from young and elderly adults.
The expression of alpha- and beta-isoforms of protein kinase C (PKC) was analyzed in the peripheral blood T and B cells from 11 elderly and young humans. Immunoblot analysis with isoenzyme specific antibodies showed that T cells from five of 11 elderly subjects exhibited selective reductions in PKC alpha which was < 60% of those in young subjects whereas the levels of PKC beta were comparable to T cells of young subjects. No age-related reductions of PKC alpha or beta were observed in B cells. Among individual elderly subjects, the reductions in T cell PKC alpha were not associated with lower levels of PKC beta thereby resulting in only approximately 60-70% reductions of combined PKC alpha plus PKC beta. In addition, the functional properties of PKC in stimulated T cells of elderly subjects with respect to activation/translocation were comparable to T cells of young subjects. These results suggest that selective alterations in PKC isoenzymes can occur in human T cells during aging which may not be readily apparent in standard enzymatic assays and may contribute to aberrancies in intracellular signal transduction.
Whisler
R L
RL
William H. Davis Medical Research Center, Department of Internal Medicine and Medical Biochemistry, Ohio State University, Columbus 43210-1228, USA.
Newhouse
Y G
YG
Grants
I S
IS
Hackshaw
K V
KV
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000378:metabolism*; D001402:B-Lymphocytes / Q000201:enzymology*; D001692:Biological Transport; D001773:Blood Cells / Q000201:enzymology*; D002118:Calcium / Q000502:physiology; D005260:Female; D006801:Humans; D015151:Immunoblotting; D007527:Isoenzymes / Q000378:metabolism*; D008297:Male; D010743:Phospholipids / Q000502:physiology; D011493:Protein Kinase C / Q000378:metabolism*; D013601:T-Lymphocytes / Q000201:enzymology*
D007527:Isoenzymes; D010743:Phospholipids; D011493:Protein Kinase C; D002118:Calcium