Lithium Chloride Intraperitoneal Injection Combined With Olfactory Ensheathing Cells Transplantation On The Vitreous Cavity Retinal Ganglion Cells

Objective:To investigate the effect of different doses of lithium chloride (LiCl) Intraperitoneal injection, Intravitreal transplantation of olfactory ensheathing cells (OEC) and combined of the two on the survival of retinal ganglion cells (RGC) after optic nerve (ON) transection in adult SD rats. And analysis the expression of brain-derived neurotrophic factor (BDNF) of the retina,do a preliminary study of its mechanism.Methods:1The left ONs of120adult female Sprague-Dawley rats were transected intraorbitally and RGCs were retrogradely-labeled with FluoroGold (FG) before they were divided into the saline control and low dose (30mg/kg/d), medium dose (60mg/kg/d) and high dose (85mg/kg/d) LiCl groups. The animals received daily intraperitoneal injections of saline or the three different doses of LiCl one day before ON transection until they were euthanized2,7or14days after ON transection. The FG-labeled surviving RGCs were counted in each whole-mounted retina using a sampling method and the mean RGCs density was then calculated in each retina. And at7and14days,Research the BDNF expression in the protein and mRNA levels of retinal2The left ONs of60adult female Sprague-Dawley rats were transected intraorbitally and RGCs were retrogradely-labeled with FluoroGold (FG) then they were divided into Intravitreal transplant the DF12group and intravitreal transplant OEC group.36of them were euthanized at7.14. and21days after ON transection. The FG-labeled surviving RGCs were counted in each whole-mounted retina using a sampling method and the mean RGCs density was then calculated in each retina. And other24of them were euthanized at7and14days,Research the BDNF expression in the protein and mRNA levels of retinal3The left ONs of48adult female Sprague-Dawley rats were transected intraorbitally and RGCs were retrogradely-labeled with FluoroGold (FG) before they were divided into Intravitreal transplant the DF12combined intraperitoneal injection saline group and intravitreal transplant OEC combined intraperitoneal injection middle Licl group.The animals received daily intraperitoneal injections of saline or LiCl one day before ON transection until they were euthanized7D and14D days after ON transection. The FG-labeled surviving RGCs were counted in each whole-mounted retina using a sampling method and the mean RGCs density was then calculated in each retina. And Research the BDNF expression in the protein and mRNA levels of retinal In the corresponding time.Results:1No significant difference (P>0.05) in the RGCs density could be detected among the control and three LiCl experimental groups2days after ON transection. When the survival time increased to7days, the RGCs densities in three LiCl groups became significantly higher (P<0.01) than that in the control group, with the highest RGCs density being in the medium dose group. In the protein and mRNA levels of retinal,the BDNF expression in three LiCl groups became significantly higher (P<0.01) than that in the control group,and the expression of middle group were significantly higher (P<0.01) than that in the low group. At the14th postoperative day. the densities in the low and medium dose groups remained higher markedly (P<0.01) than that in the control group but the density in the high dose group was similar (P>0.05) to that in the control group. In the protein and mRNA levels of retinal,the BDNF expression in low, middle LiCl groups became significantly higher (P<0.01) than that in the control group,and the expression of middle group were significantly higher (P<0.01) than that in the low group.2There were significant difference (P<0.01) in the RGCs density could be detected among intravitreal transplant DF12group and intravitreal transplant OEC group at7and14days after ON transection. And in the protein and mRNA levels of retinal, the BDNF expression of intravitreal transplant OEC group were significantly higher (P<0.01) than that in the intravitreal transplant DF12group at7D and14D after ON transection.. but at the21th postoperative day, There were no significant difference (P>0.05) in the RGCs density could be detected among intravitreal transplant DF12group and intravitreal transplant OEC group.3There were significant difference (P<0.01) in the RGCs density could be detected among intravitreal transplant DF12combined intraperitoneal injection saline group and intravitreal transplant OEC combined intraperitoneal injection middle LiCl group at7and14days after ON transection. And in the protein and mRNA levels of retinal, the BDNF expression of intravitreal transplant OEC combined intraperitoneal injection middle LiCl group were significantly higher (P<0.01) than that in the intravitreal transplant DF12combined intraperitoneal injection saline group at7and14days after ON transection.Conclusion:1Intraperitoneal injections of LiCl can promote the RGCs survival following ON transection in adult rats and such neuroprotection is dose-dependent. The most significant role in the middle dose (60mg/kg/d). And this role is worked by an increased expression of BDNF in the retina.2Intravitreal transplantation OEC compared to intravitreal transplantation DF12can promote RGCs survival in the retina,compared to Optic nerve stump transplantation OEC can extend the survival time of OEC.And this role is worked by an increased expression of BDNF in the retina.3Intravitreal transplantation OEC combined intraperitoneal injections of middle LiCl can improve the the expression of of BDNF,and promote RGCs survival time.