| Objective:To invest the response of retina glial cells to inflammation induced by intravitreal lipopolysaccharide injection and the effect of TRPV4 in the inflammation.Method:The rat received intravitreal injection of LPS to induce retinal inflammation.GFAP and IBA1 immunofluorescence staining were used to observe the activation and duration of retina Miiller glia cells and microglia cells.Immunofluorescence staining and Western blot were used to detect LPS-induced expression changes of TRPV4 protein in the retina after LPS intravitreal injection for 1 day.HC067047,a specific inhibitor of TRPV4,was injected into the vitreous cavity 30 minutes before the intravitreal injection of LPS,The expression of proinflammatory factors in the retina after TRPV4 specific regulation was detected by qPCR.Result:The retinal inflammation model was successfully induced.The expression of GFAP in retinal Müller glial cells was significantly up-regulated after intravitreal injection of LPS,and was still significantly up-regulated on the 14th day after injection.The number of microglia expressing IBA1 in the retina increased significantly and still significantly up-regulated on the 14th day after injection after injection.After intravitreal injection of LPS for 1 day,the expression of TRPV4 in the retina was significantly up-regulated.TRPV4 inhibitor HC067047 can significantly inhibit LPS-induced up-regulation mRNA expression of TRPV4 and retinal pro-inflammatory factors IL-1β,TNFα,IL6 and MMP9.Conclusions:Intravitreal injection of LPS induced retinal inflammation persisted up to 14 days after injection.In LPS-induced retinal inflammation,Retinal inflammatory response can be alleviated by reducing the expression of pro-inflammatory factors.Objective:To investigate the inflammatory injury of optic nerve head and optic nerve induced by intravitreal lipopolysaccharide injection and related mechanisms.Methods:The model of retinal inflammation was established by intravitreal injection of LPS in rats.GFAP and IBA1 immunofluorescence staining were used to detect the responses of astrocyte and microglia in optic nerve after LPS injection for 1day,7day and 14 day.The structure of optic nerve myelin sheath after LPS injection was observed by MBP immunofluorescence staining and transmission electron microscopy.The mRNA levels of proinflammatory cytokines were detected by qPCR after LPS injection for 1 day.Transcriptome sequencing was used to detect the changes in the gene expression profile of the optic nerve head 1 day after LPS injection.The expressions of GFAP,AQP4 and TRPV4 in the optic nerve head were detected by immunofluorescence staining.Results:The mean fluorescence intensity of GFAP and the number of microglia expressing IBA1 were not significantly changed after intravitreal injection of LPS for 1 day,7 day and 14 day.The mean fluorescence intensity of MBP did not change significantly,but mild demyelination of the optic nerve after LPS injection was observed in transmission electron microscopy.The mRNA levels of proinflammatory cytokines did not change significantly 1 day after LPS injection.Transcriptome sequencing of optic nerve head showed that there were significant differences in molecular transcription levels between the two groups.The protein level of GFAP and AQP4,the specific markers of astrocytes,did not change significantly in the optic nerve head,and the expression of TRPV4 protein did not change significantly in the optic nerve head too.Conclnsions:The results suggest that LPS in the vitreous cavity may notenter into the optic nerve directly,thus causing significant activation of astrocytes and microglias of the optic nerve,but causing mild demyelination of the optic nerve.Intravenous injection of LPS induced significant changes in the transcriptional level of the optic nerve head,implying that the optic nerve head may play a barrier role in the spread of retinal inflammation to the optic nerve. |
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