Dual Modulation of Adipogenesis and Apoptosis by PPARG Agonist Rosiglitazone and Antagonist Betulinic Acid in 3T3-L1 Cells.

Background/Objectives: Disruptions in adipose tissue dynamics contribute to obesity-related metabolic disorders, emphasizing the need for targeted therapies focusing on adipose tissue cells, including progenitor cells and adipocytes. Peroxisome proliferator-activated receptor gamma (PPARG) ligands are potent insulin sensitizers used in type 2 diabetes treatment. This study investigated the effects of rosiglitazone, a PPARG agonist, and betulinic acid, a PPARG antagonist, on adipogenesis and apoptosis in 3T3-L1 pre-adipocytes. Method: 3T3-L1 pre-adipocytes were treated with rosiglitazone or betulinic acid during adipogenic differentiation. Lipid droplet formation was used to evaluate adipogenesis. Cell growth and cell death were assessed using the resazurin-based cell viability assay, trypan blue exclusion assay, LDH assay, and Annexin V/PI staining. Quantitative PCR was conducted to examine the expression of genes associated with adipogenesis and apoptosis. Results: Betulinic acid reduced adipogenesis only when administered daily for eight days. Rosiglitazone did not alter the overall lipid quantity; however, it promoted a shift toward fewer but larger lipid droplets. Both compounds increased Adipoq and Cfd expression, and betulinic acid also elevated Fabp4. Rosiglitazone induced stronger cell aggregation. Despite increased cell death, overall viability was maintained. Apoptotic cell death was enhanced by both compounds and confirmed via Annexin V/PI staining and flow cytometry, accompanied by downregulation of Ccnd1 and Bcl2. Additionally, rosiglitazone markedly increased the expression of Cebpa, a key regulator that can modulate lipid droplet formation and the balance between cell growth and death. Conclusions: Rosiglitazone and betulinic acid differentially modulate adipogenesis and apoptosis in 3T3-L1 cells, revealing a complex interplay between lipid accumulation and programmed cell death. Together, the findings underscore the potential of dual PPARG-targeting approaches for metabolic disease interventions.