Furthermore, Ala deceased the density of cardiac fibrosis, as assessed by Masson and Sirius red staining; reduced expression of fibrotic proteins, including connective tissue growth factor, collagen I (COL1A1) and matrix metalloproteinase 9, was also observed.
Expression levels of IL-33/ST2 pathway factors in myocardial tissue were significantly associated with cardiac fibrosis and the expression levels of CTGF and TGFβ1.
The matricellular protein connective tissue growth factor (CTGF), or CCN2, is strongly produced by injured cardiomyocytes and although it is considered a pro-fibrotic factor in many organ systems, its role in cardiac fibrosis is controversial.
These effects of Rh2 were reversed by GSK0660 or siRNA specific for PPARδ Taken together, PPARδ activation may inhibit STAT3 activation to reduce CCN2 and fibronectin expression in diabetic rats with cardiac fibrosis.
In conclusion, while STAT3 regulates matrix metalloproteinase-9 and connective tissue growth factor expression in diabetic rats with cardiac fibrosis, cryptotanshinone inhibited fibrosis to improve cardiac function by suppressing the STAT3 pathway.