Omidenepag, a Selective, Prostanoid EP2 Agonist, Does Not Suppress Adipogenesis in 3D Organoids of Human Orbital Fibroblasts.

Purpose: The purpose of this study was to present the effects of the prostanoid EP2 agonist, omidenepag (OMD) on human orbital fibroblasts (HOFs) using a three-dimension (3D) cell culture. Methods: During adipogenesis of 3D HOFs organoids, changes in size, lipids staining, mRNA expression of adipogenesis related genes, PPARγ, AP2, and ADIPOQ, and extracellular matrix, collagen 1 (COL 1), COL 4, COL 6, and fibronectin (FN), and stiffness by a micro-squeezer were examined in the presence and absence of either 100 nM bimatoprost acid (BIM-A) or 10, 100, or 10,000 nM OMD. Results: The size of the 3D organoids increased dramatically during adipogenesis, and these were further enhanced in the presence of OMD in contrast to the BIM-A induced suppression effect. The intensity of lipid staining and the mRNA expression of PPARγ were significantly increased upon adipogenesis, and both or latter was markedly inhibited in the presence of OMD or BIM-A, respectively. AP2 expression was also upregulated by adipogenesis, and was further enhanced by BIM-A. The adipogenesis-induced downregulation of COL 1 and FN, or the upregulation of the expression of COL 4 and COL 6 were all suppressed in the presence of BIM-A. In contrast, OMD caused similar effects on COL 4, COL 6, or FN expression, but caused a significant increase in COL 1 expression. Stiffness was significantly increased upon adipogenesis, and was further increased or substantially decreased by BIM-A or OMD, respectively. Conclusions: The present study indicates that the FP2 agonist, OMD, had different effects on 3D HOFs organoids, as compared to BIM-A. Translational Relevance: The current study suggests that OMD may not induce deepening of upper eyelid sulcus (DUES).