Fig. 1.

PGC-1β was increased in diabetic heart. a–c KEGG pathway analysis of DEGs between diabetic hearts and normal ones. Genes altered at 3 day (a), 28 day (b), 42 day (c) after diabetes induction were obtained by statistical reanalysis of the GSE4745 data. Bubble diagrams were generated using ggplot2 package. The y-axis shows the name of KEGG pathway; and the enrichment factor in x-axis denotes the ratio of the number of DEGs to the number of all unigenes in each reference pathway. The color of the dot represents p-value, and the size of the dot represents the exact number of DEGs mapped to this pathway. Cardiac tissues used in d–g were from 28-week-old male db/db mice and their C57 littermates. d Western blots and quantitative analysis of PGC-1β in the heart tissues. β-actin was used as an internal control. e Representative images and quantitative analysis of oil red O staining of cardiac lipid deposition (n = 5–8, bar = 50 μm). f Representative images and quantification of DHE staining of cardiac ROS production (n = 5–8, bar = 50 μm). g Representative images and quantification of TUNEL assay determining cell apoptosis in heart tissues (n = 5–8, bar = 100 μm). For d–f, data are expressed as mean ± SEM, *p < 0.05. DEG indicates differently expressed gene. DHE dihydroethidium, ROS reactive oxygen species, TUNEL TdT-mediated dUTP nick-end labeling