RNA-seq analyses of mouse retinal pigment epithelium cells

The retinal pigment epithelium (RPE) is a monolayer of polarized epithelial cells lying between the retina and the choroid/sclera, with a major function in supporting photoreceptor homeostasis, but the role of RPE in eye size regulation is yet to be further explored. it was recently reported that selective deletion of Low density lipoprotein receptor-related protein 2 (Lrp2) in the mouse RPE resulted in large eyes, similar to the phenotypes of Lrp2 whole eye knockout mice, suggesting that the RPE is the tissue in which LRP2 functions. Here, to investigate which downstream pathways of Srebp2 and Lrp2 are responsible for regulating eye growth, we performed RNA-seq analysis with the mouse RPE tissues. Postnatal day 0 (P0) mice were injected with AAV8-Best1-GFP/nSrebp2/ctrl sh/Lrp2 sh1/Lrp2 sh2 viruses to overexpress the constitutively active form of Srebp2 or to knockdown Lrp2 in the RPE specifically. At P14, RPE cells were carefully dissociated for RNA extraction. Via RNA-seq analysis and functional validation, we identified that Bmp2 is the target and the effector of the Srebp2-Lrp2 pathway. Overall, the present study unveils an essential role of RPE in regulating eye size via the Srebp2-Lrp2-Bmp2 signaling pathway, shedding light on the underlying mechanism of eye size control. Overall design: Retinal pigment epithelium (RPE) mRNA profiles of postnatal day 14 mice injected with AAV8-Best1-GFP/nSrebp2/ctrl sh/Lrp2 sh1/Lrp2 sh2 viruses