Therapeutic effect of a traditional Chinese medicine formulation on experimental choroidal neovascularization in mouse

AIM:To investigate therapeutic effects of traditional Chinese medicine formulations,Hexuemingmu(HXMM)on laser-induced choroidal neovascularization(CNV)and followup effect in mice.METHODS:C57 BL/6 mice of 8-week-old were used and CNV was induced with 577 nm laser photocoagulation.Animals were randomly divided into groups and different doses of HXMM were administered daily.One,four,and eight weeks after the intervention,the electroretinogram(ERG),fundus fluorescence angiography,choroidal flat mount and immunofluorescence staining were preformed to evaluate the function and CNV formation.The expression levels of angiogenic proteins were determined by Western blotting and immunofluorescence staining.An analysis of variance and Kruskal-Wallis test were used to test the differences among the groups.RESULTS:The results showed that HXMM effectively increased amplitude of ERG of mice(P<0.05),alleviated fundus CNV leakage(P<0.05),and reduced the area of neovascularization and the expression of angiogenic proteins(P<0.05)after laser-induced CNV.CONCLUSION:HXMM can protect the retinal function of mice after laser-induced CNV,and inhibit the CNV development.

Müller cells are activated in response to retinal outer nuclear layer degeneration in rats subjected to simulated weightlessness conditions

A microgravity environment has been shown to cause ocular damage and affect visual acuity,but the underlying mechanisms remain unclear.Therefore,we established an animal model of weightlessness via tail suspension to examine the pathological changes and molecular mechanisms of retinal damage under microgravity.After 4 weeks of tail suspension,there were no notable alterations in retinal function and morphology,while after 8 weeks of tail suspension,significant reductions in retinal function were observed,and the outer nuclear layer was thinner,with abundant apoptotic cells.To investigate the mechanism underlying the degenerative changes that occurred in the outer nuclear layer of the retina,proteomics was used to analyze differentially expressed proteins in rat retinas after 8 weeks of tail suspension.The results showed that the expression levels of fibroblast growth factor 2(also known as basic fibroblast growth factor)and glial fibrillary acidic protein,which are closely related to Müller cell activation,were significantly upregulated.In addition,Müller cell regeneration and Müller cell gliosis were observed after 4 and 8 weeks,respectively,of simulated weightlessness.These findings indicate that Müller cells play an important regulatory role in retinal outer nuclear layer degeneration during weightlessness.

Necroptosis plays a crucial role in the exacerbation of retinal injury after blunt ocular trauma

Retinal injury after blunt ocular trauma may directly affect prognosis and lead to vision loss.To investigate the pathological changes and molecular mechanisms involved in retinal injury after blunt ocular trauma,we established a weight drop injury model of blunt ocular trauma in male Beagle dogs.Hematoxylin-eosin staining,immunofluorescence staining,western blotting,and TUNEL assays were performed to investigate retinal injury within 14 days after blunt ocular trauma.Compared with the control group,the thicknesses of the inner and outer nuclear layers,as well as the number of retinal ganglion cells,gradually decreased within 14 days after injury.The number of bipolar cells in the inner nuclear layer began to decrease 1 day after injury,while the numbers of cholinergic and amacrine cells in the inner nuclear layer did not decrease until 7 days after injury.Moreover,retinal cell necroptosis increased with time after injury;it progressed from the ganglion cell layer to the outer nuclear layer.Visual electrophysiological findings indicated that visual impairment began on the first day after injury and worsened over time.Additionally,blunt ocular trauma induced nerve regeneration and Müller glial hyperplasia;it also resulted in the recruitment of microglia to the retina and polarization of those microglia to the M1 phenotype.These findings suggest that necroptosis plays an important role in exacerbating retinal injury after blunt ocular trauma via gliosis and neuroinflammation.Such a role has important implications for the development of therapeutic strategies.

Frequency cumulative effect of subthreshold energy laser-activated remote phosphors irradiation on visual function in guinea pigs

AIM:To explore the effects of laser-activated remote phosphors(LARP)on visual function in guinea pigs.METHODS:Electroretinogram(ERG)of guinea pigs were observed after LARP irradiation at different frequencies and irradiation times.We evaluated the expression of rhodopsin,β-catenin,connexin36,calretinin,and calbindin in the retina of guinea pigs and measured the density of photoreceptor cells after high-frequency LARP irradiation.RESULTS:After LARP irradiation,the ERG results showed that the amplitude of the dark-adapted 3.0 b-wave of the model eye was lower than that of the control eye after high-frequency irradiation(P<0.05).The expression of rhodopsin,β-catenin,connexin36,calretinin,and calbindin in the retina of guinea pig declined.CONCLUSION:There is frequency cumulative damage effect on the retina that relates to LARP illumination frequency.This has significance for staff visual protection policies under LARP lighting conditions.

Shenfu injection attenuates neurotoxicity of bupivacaine in cultured mouse spinal cord neurons

Background Our previous in vivo study in the rat demonstrates that Shenfu injection, a clinically used extract preparation from Chinese herbs, attenuates neural and cardiac toxicity induced by intravenous infusion of bupivacaine, a local anesthetic. This study was designed to investigate whether bupivacaine could induce a toxic effect in pnmary cultured mouse spinal cord neuron and if so, whether the Shenfu injection had a similar neuroprotective effect in the cell model. Methods The spinal cords from 11 - to 14-day-old fetal mice were minced and incubated. Cytarabine was added into the medium to inhibit the proliferation of non-neuronal cells. The immunocytochemical staining of β-tubulin was used to determine the identity of cultured cells. The cultured neurons were randomly assigned into three sets treated with various doses of bupivacaine, Shenfu and bupivacaine＋Shenfu, for 48 hours respectively. Cell viability in each group was analyzed by methyl thiazoleterazolium （MTT） assay. Results The viability of the cultured neurons treated with bupivacaine at concentrations of 0.01%, 0.02%, 0.04% and 0.08% was decreased in a dose-dependent manner. Although the Shenfu injection at concentrations ranging from 1/50 to 1/12.5 （VN） had no significant influence on the viability of cultured neurons （P〈0.05 vs control）, the injection significantly increased the cellular viability of cultured neurons pretreated with 0.03% bupivacaine （P〈0.05）. Conclusion Although Shenfu injection itself has no effect on spinal neurons, it was able to reduce the bupivacaineinduced neurotoxicity in vitro.