CCN1 and diabetes mellitus: Hence, we propose that CCN1/ERK1/2/EGR1 is important for reducing myocardial injury in diabetes, as supported by our findings with RT-PCR and western blotting analysis indicating that MOTS-c reduced mRNA expression levels of CCN1, ERK1/2 and EGR1, and protein expression levels of CCN1 and EGR1 in the hearts of diabetic rats, but without affecting ERK1/2 total protein expression (Figures 6, 7).