mIGF-1 transgenic expression protects against DNA damage and increases expression of the mitochondrial protein UCP1. A, TUNEL assay analysis of WT (upper panel) and TG hearts (lower panels) 1 week after CTX injection. White arrows in the WT heart indicate TUNEL-positive nuclei, whereas the TG heart showed a nonspecific signal. Red outline demarcates the border of the injury. B, Percentage amount of TUNEL-positive cells 1 week after CTX injection. Asterisk (*) indicates a significant decrease of apoptotic cells in TG hearts. C, Expression analysis of the pro-apoptotic markers Bax and Bcl-xL 6 hours, 24 hours, and 1 week after CTX injection. D, UCP1 RT-PCR of uninjured WT and TG hearts and injured WT and TG hearts 24 hours after CTX injection. Asterisk indicates a significant increase of UCP1 transcripts in TG hearts compared with WT hearts with or without CTX-induced infarct. § indicates UCP1 increasing levels compared with uninjured hearts. E, Affymetrix analysis of UCP1. The transcript is expressed as logarithmic scale of intensity in 2 TG and WT hearts. * indicates a significant increase of UCP1 transcripts in TG hearts.