Human pluripotent stem cells derived endothelial cells repair choroidal ischemia

Abstract

Purpose : Choroidal atrophy is a common fundus pathological change closely related to the development of age-related macular degeneration (AMD), retinitis pigmentosa, and pathological myopia. Studies suggested that choroidal endothelial cells (CECs) that form the choriocapillaris vessels are the first cells lost in choroidal atrophy. Therefore, restoring the choriocapillaris vessels is crucial to the prognosis of the above diseases. We hypothesize that transplanting human pluripotent stem cell derived endothelial cells (hPSC-ECs) could regenerate blood vessels in a rat choroid ischemia model.

Methods : We first confirmed the choroid characteristics of hPSC-ECs by immunostaining choroid-specific markers like CA4, RGCC and CD31. Then we transplanted 1μL of 5×10⁴ hPSC-ECs into the suprachoroidal space of a rat model of choroid ischemia or 1 μL of EC culture media as control (N=24 for each group). Confirmation of graft survival was achieved by immunostaining of human-specific CD31 and human nucleus markers at 7, 14, 30 and 90 days. Morphological assessments of choroid thickness and vessel regeneration were conducted for up to 90 days post-transplantation with H&E staining images and fundus angiography/indocyanine angiography (FA/ICG) images analyzed by AngioTool. Unpaired t-tests were used for statistical analysis.

Results : We found that hPSC-ECs through the MESP1+ mesodermal progenitor stage expressed CECs-specific markers and can integrate into choriocapillaris. In a rat model of choroid ischemia, transplantation of hPSC-ECs into the suprachoroidal space increased choroid thickness (p<0.0005) and vessel junction density (p<0.05 in FA/ICG images). Close-up immunostaining examination showed that engrafted hPSC-ECs formed new blood vessels and integrated with existing rat vessels.

Conclusions : Our work demonstrated that hPSC-ECs could be used to repair choroidal ischemia in the animal model, which may lead to a new therapy to alleviate choroidal atrophy implicated in AMD and other ocular diseases such as retinitis pigmentosa, and pathological myopia.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.