Abstract
Abstract: :
Purpose: To examine if retinal stem cells are present in the membranes surgically excised from patients with proliferative vitreoretinopathy (PVR) Methods: Surgical membranes were collected from patients with chronic retinal detachment associated with PVR (N=16). Tissues were fixed in 1% formaldehyde. 6µ paraffin sections were cut on a cryostat from embedded samples. The membranes were deparaffinized and exposed to primary antibodies of Nestin, Notch, and Chx–10. After overnight incubation at 4oC, slides were incubated with conjugated secondary antibodies. DAB chromagen was added to visualize the peroxidase–conjugated second antibody. Cell nuclei were stained with DAPI during the last rinse. Slides were mounted, and examined using a Zeiss Axioscop 2. Results: Specific attention was paid to cells that showed positive staining for all the markers. Positive cells are most prominent in the membranes from ora serrata, possesed fibrillary processes, small amounts of perinuclear cytoplasm, and were arranged radially within or superficially on the retina. Specific areas of co–flourescence with notch and chx–10 was most prominent in this area. In the posterior retina, speckled cytoplasmic nestin staining is seen around the nuclei of neurons. Occasional positive staining of glial cells was also noted. These cells appear to represent nestin positive neurons. In epiretinal membranes patches of elongated nestin positive cells were found. Conclusions: Retinal progenitor cells, immunolocalized with three known stem cell markers were present predominantly in membranes from ora serrata in tissue removed from patients with PVR. These cells represent a population of progenitor cells from normal adult human retina that may dedifferentiate and participate in reparative process of the retina .
Keywords: immunohistochemistry • proliferative vitreoretinopathy • detection