Neuroprotection Of ProIyl-4-Hydroxylases Inhibitor Against Photoreceptor Damage Of Experimental Retinal Detachment By Mitophagy

PURPOSE.To investigate the neuroprotective effect of prolyl-4-hydroxylases inhibitor(PHI)against photoreceptor damage,by stabilizing HIF-1?,in experimental retinal detachment(RD).METHODS.RD was created in Brown Norway rats by subretinal injection of 10mg/ml sodium hyaluronate.FG-4592(a PHI,25 mg/kg)or DMSO was administered every 2 days by retroorbital injecting.TdT-dUTP terminal nick-end labeling(TUNEL)assay was used to evaluate the photoreceptor apoptosis 3 days after RD.The thickness of the outer nuclear layer(ONL)7 days after RD was used to represent the number of residual photoreceptors.Western Blot and immunofluorescence were used to detecte the mitophagy-related markers,such as hypoxia inducible factor 1?(HIF-1?),BCL2/ade novirus E1[19 kDa protein-interacting protein 3(BNIP3),autop ha gy-re lated gene 5(Atg5),microtubuleassociated protein 1 light chain 3(LC3),and FUN 14 domain containing 1(FUNDC1).Transmission electron microscopy(TEM)was used to observe autophagic vacuoles and mitochondria.In situ detection with dihydroethidium(DHE)was used to measure the reactive oxygen species(ROS).RESULTS.The Expression of HIF-1? and BNIP3 significantly increased with PHI treatment(P<0.05),followed by higher 33KD Atg5/24KD Atg5 and LC3-?/LC3-?(P<0.05).More FUNDC1 was colocated with LC3 and more punctate LC3 form was detected with PHI treatment.More autophagic vacuoles engulfing mitochondria were detected by TEM after PHI treatment.The damage of mitochondria of PHI group was slighter than DMSO group with TEM observation,followed by decreased ROS with DHE detection(P<0.05).The number of TUNEL-positive photoreceptors 3 days after RD of PHI group was less than DMSO group(P<0.05),and the thickness of ONL 7 days after RD of PHI group was higher than DMSO group(P<0.05).CONCLUSIONS.PHI treatment can protect against photoreceptor cell death of RD,by stabilizing HIF-la along with increased BNIP3,followed by enhancement of mitophagy and decreased ROS generation.