Fig. 6

PGC-1α isoform expression in heart at baseline and 3- and 16 days post I/R. Expression levels at baseline (black bars) and 3 or 16 days post sham surgery (sham, white bars) or ischemia / reperfusion injury (I/R, striped bars) for different PGC-1α starting exons (A–D), for the four group-wise testable isoforms (E–H) and for the four single-detectable isoforms (I–L). Housekeeper-normalized expression values in infarct area (upper row) and remote area (bottom row). A Exon 1a, originating from the canonical promoter. B, C Exons 1b and 1b’, under control of the alternative (known) promoter. D Novel exon 1c, originating from a new promoter site. E Isoforms with canonical C-terminal ending. F Isoforms with novel C-terminal ending. G N-terminal isoforms. H Isoforms with the novel exon 6b. I PGC-1α-trE6-Ex13c. J sNT-PGC-1α. K PGC-1α-E3c. L CT-PGC-1α-E3c. I/R leads to downregulation of canonical and novel PGC-1α starting exons as well as most of the single- and group-wise-detectable PGC-1α isoforms 3 days post I/R, suggesting a general downregulation of PGC-1α in infarct area 3 days post I/R. At 16 days post I/R, a recovery can be observed. Moreover, PGC-1α-trE6-Ex13c is showing ‘overcompensative’ behaviour in infarcted and remote area. In all other isoforms, the expression in the remote area is not affected, neither at day 3 nor 16 days post infarction. Detailed description, see text. Data acquired by qPCR using cDNA using primers covering specific starting exon 1 (a, b, b’ or c) and exon 2 resp. using primers covering specific exon-exon junctions. Expression values are normalized to housekeeper NUDC. n = 4 each, bars depict mean values, error bars represent SD. Significance calculated by unpaired Student’s t test (ns p > 0.05, *p ≤ 0.05, **p ≤ 0.01, ***p ≤ 0.001)