Abstract
Purpose: :
To investigate the proliferation of retinal stem cells in the proliferating marginal region of RCS rats during development of Retinitis Pigmentosa.
Methods: :
RCS rats were divided into 3 groups randomly: the initial stage group (P15d), the mid-stage group (P30d) and the advanced stage group (P90d) according to the severity of degeneration (n=4 in each group). Age-matched Long-Evan’s rats without retinal degeneration served as controls. The thickness of outer nuclear layer (ONL) was detected using DAPI immunofluorescence staining; A transcription factor (Chx-10) expressed by retinal stem cell/ progenitors and thymidine analog BrdU incorporated in proliferating cells were detected using immunofluorescence staining, and positive cells were counted per vision in the proliferating marginal region of the retinal.
Results: :
Compared with Long-Evan’s rats age-matched, the thickness of ONL of RCS rats decreased as aging from P15, almost disappeared in P90 RCS rats. There was no significant difference between the quantity of Chx-10 positive cells in P15 RCS rats and in P15 Long-Evan’s rats(P>0.05). As compared with Long-Evan’s rats age-matched, the quantity of Chx-10 positive cells both in P30 and P90 RCS rats increased (P<0.05); While groups of RCS rats compared with each other, the P30 group increaced markedly (P<0.01). 3) There were more BrdU positve cells in goups of RCS rats than that in the groups of Long-Evan’s rats age-matched, in which BrdU positve cells could hardly be detected; Compared with P15 and P90 RCS rats, the positive cells in P30 RCS rats increaced markedly (P<0.01).
Conclusions: :
This indicated that retinal stem cells could be activated to proliferate at proliferating marginal region during a short time while retinal of RCS rats at P30 degenerated significantly.
Keywords: degenerations/dystrophies • retinal degenerations: cell biology • proliferation