Research Paper Volume 6, Issue 10 pp 820—834

Figure 5. PARP-1 inhibits SIRT-1 activity by PARylation. (A) NAD⁺ levels were determined in myotubes either in the presence or in the absence of H₂O₂ with or without the inhibition of PARP-1 by PJ34 or siRNA. (B) NAD⁺ levels were determined in myotubes either in the presence or in the absence of H₂O₂ with or without the inhibition of PARP-1 by PJ34 or siRNA. (B and C) SIRT-1 protein PARylation was determined in total cell lysates from myotubes treated with the conditions similar to ‘A’ by immunoblotting after IP. (D) PGC-1α acetylation levels were determined by immunoblotting in total cell lysates from myotubes treated with or without resveratrol. (E) SIRT-1 protein PARylation was determined in myotubes either in the presence or in the absence of H₂O₂ with or without RSV. (F) Infection of myotubes isolated from conditional knockout mice (flox/flox) with AAV2-GFP or AAV2-Cre-GFP to determine SIRT-1 knock-down. (G) PGC-1α acetylation levels were determined in total cell lysate from myotubes infected with either AAV2-GFP or AAV2-Cre-GFP in the presence or absence of RSV by immunoblotting after IP. Global cellular protein PARylation (H) and percentage of myotube survival (I) were determined in either AAV2-GFP or AAV2-Cre-GFP infected myotubes in the presence or in the absence of H₂O₂ or RSV. AAV, adeno-associated virus; GFP, green fluorescence protein; IP, immunoprecipitation; RSV, resveratrol.