Retinitis pigmentosa (RP) is a group of inherited dystrophic retinal disease that affects 1 of
4000 people worldwide. It gradually leads to visual loss through retinal neurodegeneration
with a slow and progressive process. The underlying mechanisms of the cell death are now
well studied but their interactions remain uncertain. Just before the death of the
photoreceptor, some of the cell cycle proteins are reactivated and may play an important
role. In the laboratory, some microRNAs have been identified during the photoreceptor
relapse of the Rd1 mouse model of retinal degeneration. The objectives of this study is to
understand the potential role of the miR-31 in the control of specific cell cycle proteins. For
this experiment, a mouse photoreceptor-like cell line (661W) has been cultured and
transfected with a plasmid coding for miR-31 and GFP or a scramble sequence and GFP
(control). Western Blot and qPCR allowed us to evaluate respectively the cell cycle protein
status and the corresponding mRNA status in relation to the miR-31 overexpression.
Our experiment revealed that miR-31 downregulates E2f1 cell cycle protein in 661W cells.
These results must be confirmed with supplementary experiments in vivo studies in Rd1
mouse retina.