Figure 4
Histology of hiPSC-RPE strip transplant at an RPE-damaged site (M4). (A) Low magnified hematoxylin and eosin (HE) image and the immunostaining image of the neighboring section with anti-human MERTK (hMERTK) and − RPE65 antibody in the hiPSC-RPE strip transplanted area over RPE damage. Yellow line indicates MERTK positive grafted area. (B) Immunostaining image of hMERTK and rhodopsin. Yellow line indicates hMERTK positive grafted area. (C) Engrafted RPE cells are positive for STEM121 and hMERTK on the apical side (arrows) while host RPE cells at the border show only autofluorescence but not STEM121 or hMERTK positivity (C’). (D) hMERTK on the apical side of transplanted RPE cells (arrows) face and interact with rhodopsin-positive outer segments of host photoreceptors. (E) Immunohistochemistry of type IV collagen in intact and RPE-damaged sites at 2 days after laser treatment. Expression of type IV collagen is disrupted after microsecond pulse laser treatment. (F) Expression analysis of type IV collagen in the intact, laser-damaged, and transplant sites. Expression of type IV collagen is identified at the basement membrane of transplanted RPE. (G) Expression analysis of type IV collagen at the basement membrane of hMERTK-positive RPE cells. Magnified view of yellow boxed part on the right. ONL outer nuclear layer, INL inner nuclear layer. Scale bars: (A) 200 μm, (B) 100 μm, (C,D) 10 μm, (E) 50 μm, (F) 100 μm, (G) 50 μm.
