Sirtuins Expression Changes And Resveratrol Activated SIRT1 To Regulate Mitochondrial Dynamics In Acute Transient Rat Retinal Ischemic Injury

Objective:Oxidative stress induced mitochondrial dysfunction and eventually lead to retinal ganglion cell death. Resveratrol has anti-inflammatory effects of oxidative stress, and its protective effect by activating Sirt1. However, whether resveratrol can activate Sirt1 to protect mitochondria in an unknown phase. Enough emerging studies focus on Sirtuins,how the Sirtuins changes in the field of ophthalmologyu are unknown. So this study not just examine the expression pattern analysis of sirtuin family members related to retinal ischemic injury in rat retina and optic nerve,but also to investigate the protective effect of resveratrol on mitochondria and whether mediated by Sirt1 in rat transient retinal ischemic injury model. Methods:(1) Randomly select right eye to make acute transient retinal ischemic injury, left eye as a control group. After that,to extract retinal tissue protein and examine Sirtuins,SIRT1, OPA1, Drp1 protein expression at 1d, 3d, 7d respectively.(2) To examine SIRT1 and OPA1 expression on normal adult rat retina by immunofluorescence,but also to examine Sirtuin family members expression on rat retina and optic nerve by immunofluorescence.(3) To give resveratrol treatment immediately after rat acute retinal ischemic injury and to examine SIRT1,OPA1, Drp1 protein expression after 7d 。(4) To investigate sirt1、opa1、drp1and Sirtuins mRNA expression by q-PCR.(5) To investigate the correlationship between sirt1 and opa1 by immunoprecipitation. Results:(1) Sirtuins 、OAP1 and SIRT1 mainly express in the retinal ganglion cell layer, inner nuclear layer, outer nuclear layer in normal rat retina, and in which OAP1 and SIRT1 togetherly express in retinal ganglion cells cytoplasm.(2) Compared with control group,Sirtuins proteins expression are different.Compared with control group,sirt1 protein expression has no change at 1d,which decreasingly express at 3d and 7d after retinal ischemic injury and 7d decreases significantly(* p <0.05).Compared with control group, opa1 protein expression increase after retinal ischemic injury at 1d,but opa1 protein expression has decreased after 3d, 7d, and 7d decreased significantly(* p <0.05). Compared with control group,drp1 express decreased at 1d after rat retinal ischemic injury(* p <0.05),however,drp1 protein express increased at 3d and drp1 continuely decrease at 7d again(** p <0.01) after rat retinal ischemic injury.(3) Compared with control group, OPA1 express decreased significantly(*p<0.05) at 7d after retinal ischemic injury; after RSV treatment, OPA1 express increased significantly again(*p<0.05) compared with 7d.And Drp1 express decreased at 7d(*p<0.05), and after RSV treatment, Drp1 express continuely decline(*p <0.05) compared with control group, but there is no significant difference between 7d and 7d +RSV(P> 0.05);SIRT1 express decreased significantly(*p<0.05) at 7d after retinal ischemic injury; after RSV treatment, SIRT1 express increased significantly again(*p<0.05) compared with 7d.(4) Compared with control group, Sirtuins mRNA are not the same.Compared with control group,opa1 mRNA express decreased significantly(*p<0.05) at 7d after retinal ischemic injury; after RSV treatment,opa1 mRNA express increased significantly again(*p<0.05) compared with 7d.And drp1 mRNA express decreased at 7d(*p<0.05), and after RSV treatment, drp1 mRNA express increased significantly again(*p <0.05) compared with 7d group.sirt1 mRNA express decreased significantly(*p<0.05) at 7d after retinal ischemic injury; after RSV treatment,sirt1 mRNA express increased significantly again(*p<0.05) compared with 7d.(5) SIRT1 and OPA1 have no direct influence. Conclusion:(1) Sirtuin family members differently expressed in rat retina and optic nerve.(2) Sirt1 has a decreased expression after rat retinal ischemic injury, however, opa1 protein express first increased and then decreased,and drp1,compared with opa1,which has a opposite expression.(3) Resveratrol has a protective effect on sirt1, which also protect mitochondria and promote the fusion of mitochondria while inhibit its fission.