Study Reveals Promising Drug Target for Full-course DR

Researchers believe the association between PPARG enhancement and lower DR risk may be dependent on the protein’s glucose-lowering effect. The protective mechanism of PPARG agonists still needs to be further explored through animal studies and clinical trials. Click image to enlarge. Dyslipidaemia is a common comorbidity of diabetes mellitus (DM), and levels of various lipids are believed to play a role in the development and worsening of diabetic retinopathy (DR). A new study aimed to evaluate the relationship between lipid traits, lipid-lowering drug targets and full-course DR, from preclinical to proliferative stages. Its findings, published recently in British Journal of Ophthalmology, revealed that enhancement of peroxisome proliferator-activated receptor gamma (PPARG) was associated with lower risks of severe DR.Using a Mendelian randomization (MR) analysis method, researchers specifically selected genetic variants that directly impact PPARG activity—known to affect lipid metabolism and insulin sensitivity—and observed their influence on a cohort predisposed to varying stages of DR.Interestingly, the data failed to show an association between lipid traits and DR. However, it did reveal that the activation of PPARG led to significantly lower levels of fasting insulin and glycated hemoglobin (HbA1c), which are critical markers of effective diabetes management and indicators of lowered retinopathy risk. These two markers mediated most of the association between PPARG and full-course DR, leading researchers to suggest that “the mechanism of the PPARG agonists’ protection of full-course DR may be dependent on the glucose-lowering effect.”In the discussion portion of their paper, the study authors further elucidate the mechanisms of action driving the association between PPARG enhancement and lower DR risk. “PPARG is the main modulator of adipogenesis, which can enhance lipid storage, insulin sensitivity and glucose metabolism through the lipid-stealing effect,” they explained. “Furthermore, PPARG is associated with inflammation, angiogenesis, neural homeostasis and redox balance, which are all vital pathological mechanisms of DR.”While these links between PPARG activity and DR have been demonstrated previously in mice, the authors of the present study vow to “further explore the role of PPARG in the occurrence and development of DR through animal experiments and clinical trials.” Moreover, they note, “It is necessary to further explore the specific effects of PPARG agonists on the retinal structure of DR patients through ophthalmic examinations (e.g., OCT, electroretinogram) to better understand the protective mechanism of PPARG agonists.” Click here for the journal source.  Cao J, Su T, Chen S, et al. Evaluating lipid-lowering drug targets for full-course diabetic retinopathy. Br J Ophthalmol. April 21, 2025. [Epub ahead of print].