Cardio-protective determinants are conserved in aged human myocardium after ischemic preconditioning.
Ischemic preconditioning (IPrec) improves post-ischemic dysfunctions of the myocardium along with activation of protein kinase C isozymes including PKCdelta. Moreover, expression of cardio-protective determinants can reduce ischemic damages. Because IPrec is limited in aged hearts, we assessed in an experimental model the impact of aging on PKCdelta and selected protective proteins in the preconditioned myocardium from adult (< or =55) and older (> or =70 years) humans. Adult myocardium showed PKCdelta up-regulation after IPrec along with improved post-ischemic contractility. Although there was no functional benefit, PKCdelta increased in older myocardium as well. Subsequent mRNA analyses demonstrated that IPrec stabilizes the mRNA expression of protective proteins (Hsp70, Bcl-2/-xL, IAPs) in both aging groups. Moreover, older hearts revealed increase in post-ischemic Hsp90beta. Our study indicates, that IPrec conserves the expression of cardio-protective determinants in aged hearts despite limited functional recovery.
Bartling
Babett
B
Clinic of Cardio-thoracic Surgery, Martin Luther University Halle-Wittenberg, Ernst-Grube-Str. 40, D-61120, Halle/Saale, Germany. babett.barling@medizin.uni-halle.de
Hilgefort
Claas
C
Friedrich
Ivar
I
Silber
Rolf Edgar
RE
Simm
Andreas
A
D000199:Actins / Q000032:analysis / Q000096:biosynthesis; D000367:Age Factors; D000368:Aged; D016275:Atrial Function / Q000502:physiology; D017931:DNA Primers / Q000235:genetics; D018841:HSP90 Heat-Shock Proteins / Q000378:metabolism; D006801:Humans; D019157:Ischemic Preconditioning, Myocardial; D007527:Isoenzymes / Q000378:metabolism; D008875:Middle Aged; D009200:Myocardial Contraction / Q000502:physiology; D009206:Myocardium / Q000378:metabolism*; D020011:Protective Agents / Q000378:metabolism*; D011493:Protein Kinase C / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D015854:Up-Regulation
D000199:Actins; D017931:DNA Primers; D018841:HSP90 Heat-Shock Proteins; D007527:Isoenzymes; D020011:Protective Agents; D012333:RNA, Messenger; D011493:Protein Kinase C