RXRA and diabetic retinopathy: Figure 5D shows that the retinal explants cultured in the media with high glucose (to model diabetic retinopathy) and supplemented with rexinoid 3 and rexinoid 6 [30] demonstrated significant upregulations of Rxrα, Rxrβ, and Rxrγ mRNAs at 24 h. We next examined the expression of the Pparα and Pparγ genes and found significant increases in their expression as well.