ObjectiveTo investigate the neuroprotective effects and mechanisms of selective histone deacetylases inhibitor MS-275 on rats after seizures. MethodsA total of 75 rats were randomly divided into 5 groups for treatment:control group,pilocarpine group, treatment group Ⅰ(administered with MS-275, 20mg/kg, once a day,intraperitoneally in 7 consecutive days), treatment group Ⅱ(administered with MS-275, 40mg/kg, once a day, intraperitoneally in 7 consecutive days), MS-275 pretreatment group. We used lithium and pilocarpin to induce seizures. Behaviors of rats in each group were observed. At 72 hours after seizures, Nissl staining and immunohistochemical were respectively used to evaluate the loss of neurons and histone acetylation levels of hippocampal CA1 and CA3 regions in each group. Escape latency in the control group, treatment group Ⅰ, treatment group Ⅱ and MS-275 pretreatment group were longer than pilocarpine group(P<0.05). ResultsCompared with the pilocarpine group, rats in MS-275 pretreatment group could delay pilocarpine-induced seizures and reduce mortality (P<0.05). Degree of neuronal loss and degeneration in both treatment group Ⅰ and treatment group Ⅱ were reduced compared with the pilocarpine group (P<0.05) and the level of histone acetylation in hippocampal CA1 and CA3 regions of the rats were increased compared with the pilocarpine group (P<0.05). ConclusionHDACs inhibitors MS-275 can improve the neuronal damage, histone deacetylation of rats' brain and rats cognitive decline, which can exert an neuroprotective effect on rats after seizures, whose mechanism may be related to its antiinflammatory effect.
ObjectiveTo explore the effect of fingolimod (FTY720) on secondary nerve injury after thalamic-ventricle hemorrhage (TH-IVH) in rats.MethodsAdult male Sprague Dawley rats (clean animal) were randomly divided into 3 groups: sham group, TH-IVH group, and intervention group (FTY720 group), with 6 rats in each group. TH-IVH model was established in both TH-IVH group and FTY720 group, but only the rats in FTY720 group were treated with FTY720. The observation was conducted at the 1st, 3rd and 7th day after modeling. The main observation index included scores of neurological function, change of body weight, water content of brain tissue, the activation of inflammatory cells, the degree of neuronal degeneration and apoptosis, and the level of cell autophagy.ResultsAt the 1st, 3rd and 7th day after modeling, the change of body weight, the neurological score, brain edema and microglia activation in TH-IVH group were statistically different from those in sham group and FTY720 group (P<0.05). The number of degenerated neurons and the number of apoptotic cells in TH-IVH group were statistically different from those in sham group and FTY720 group at the 1st and 3rd day after modeling (P<0.05). The differences in the ratio of LC3Ⅱ/LC3Ⅰ protein expression andBcl-2/Bax expression were statistically significant between FTY720 group and TH-IVH group at the 1st and 3rd day after modeling (P<0.05).ConclusionsFTY720 can improve neurological function of the TH-IVH model in the acute phase, and has certain neuroprotective effect. The neuroprotective effect of FTY720 may be associated with neuronal autophagy and apoptosis regulation and immunosuppression.
ObjectiveTo observe the protective effect of etomidate (ET) on cultured retinal ganglion cells (RGC) with mechanical injury in vitro. MethodsNew Sprague-Dawley rat RGC was cultured in vitro and identified by double immunofluorescent labeling of Thy1.1 and microtubule associated protein 2. The cultured primary cells were randomly divided into control group, RGC scratch group, ET low dose group (1 μmol/L), ET medium dose group (5 μmol/L) and ET high dose group (10 μmol/L). The RGC mechanical injury model was established by using iris knife to culture cells in RGC scratch group and ET group with different concentration. Seven days after modeling, the RGC survival rate of each group was detected by cell count Kit 8 proliferation assay. The apoptosis rate of RGC was detected by Annexin Ⅴ/propyl iodide double staining. Single factor analysis of variance was used to compare the groups. The pairwise comparison between groups was tested by the least significant difference method. ResultsThe survival rates of RGC in RGC scratch group, ET low dose group, ET medium dose group and ET high dose group were (72.60±2.97)%, (73.73±1.14)%, (79.19±1.79)% and (83.88±0.94)%, respectively. The RGC apoptosis rates of control group, RGC scratch group, ET low dose group, ET medium dose group and ET high dose group were (5.08±0.17)%, (18.67±1.24)%, (17.96±0.74)%, (15.11± 0.56)% and (11.67±1.32)%, respectively. Comparison of RGC survival rate between groups: compared with RGC scratch group, the cell survival rate of ET low-dose group, ET medium-dose group and ET high-dose group was increased, and the difference between RGC scratch group and ET low-dose group was not statistically significant (P=0.728); the differences between RGC scratch group, ET medium dose group and ET high dose group were statistically significant (P＜0.001); the difference between ET medium dose group and ET high dose group was statistically significant (P=0.002). Comparison of apoptosis rate of RGC among groups: the apoptosis rate of RGC scratch group was significantly higher than that of control group, the difference was statistically significant (P＜0.001). Compared with RGC scratch group, the apoptosis rate of ET low-dose group, ET medium-dose group and ET high-dose group was decreased, and there was no statistical significance between RGC scratch group and ET low-dose group (P=0.869). The differences of apoptosis rate between RGC scratch group, ET medium dose group and ET high dose group were statistically significant (P＜0.05). The difference of apoptosis rate between ET medium dose group and ET high dose group was statistically significant (P=0.007). ConclusionET has neuroprotective effect on RGC cultured in vitro with mechanical injury, and the protective effect increases with the increase of ET dose in a certain range.
Primary or secondary death of retinal ganglion cells (RGC) is a common outcome in various optic neuropathies, often resulting in severe visual damage. The inherent characteristics of RGC include the continuous upregulation of intracellular growth-inhibitory transcription factors and the downregulation of growth-inducing transcription factors during cell differentiation. Additionally, the external inhibitory microenvironment following RGC damage, including oxidative stress, chronic inflammation, lack of neurotrophic factors, high expression of myelin proteins, and the formation of glial scars, all restrict axonal regeneration. Both intrinsic and extrinsic factors lead to the death of damaged RGC and hinder axonal regeneration. Various neuroprotective agents and methods attempt to promote neuroprotection and axonal regeneration from both intrinsic and extrinsic aspects, and well knowledge of these neuroprotective strategies is of significant importance for promoting the neuroprotective experimental research and facilitating its translation into clinical practice.
ObjectiveTo observe the morphological and functional changes of retinal degeneration in mice with CLN7 neuronal ceroid-lipofuscinosis, and the therapeutic effects of glial cell derived neurotrophic factor (GDNF) and/or ciliary neurotrophic factor (CNTF) based on neural stem cells (NSC) on mouse photoreceptor cells. MethodsA total of 100 CLN7 mice aged 14 days were randomly divided into the experimental group and the control group, with 80 and 20 mice respectively. Twenty C57BL/6J mice aged 14 days were assigned as wild-type group (WT group). Mice in control group and WT group did not receive any interventions. At 2, 4, and 6 months of age, immunohistochemical staining was conducted to examine alterations in the distribution and quantity of cones, rod-bipolar cells, and cone-bipolar cells within the retinal of mice while electroretinography (ERG) examination was utilized to record scotopic a and b-waves and photopic b-wave amplitudes. At 14 days of age, the mice in the experimental group were intravitreally injected with 2 μl of CNTF-NSC, GDNF-NSC, and a 1:1 cell mixture of CNTF-NSC and GDNF-NSC (GDNF/CNTF-NSC). Those mice were then subdivided into the CNTF-NSC group, the GDNF-NSC group, and the GDNF/CNTF-NSC group accordingly. The contralateral eyes of the mice were injected with 2 μl of control NSC without neurotrophic factor (NTF) as their own control group. At 2 and 4 months of age, the rows of photoreceptor cells in mice was observed by immunohistochemical staining while ERG was performed to record amplitudes. At 4 months of age, the differentiation of grafted NSC and the expression of NTF were observed. Statistical comparisons between the groups were performed using a two-way ANOVA. ResultsCompared with WT group, the density of cones in the peripheral region of the control group at 2, 4 and 6 months of age (F=285.10), rod-bipolar cell density in central and peripheral retina (F=823.20, 346.20), cone-bipolar cell density (F=356.30, 210.60) and the scotopic amplitude of a and b waves (F=1 911.00, 387.10) in central and peripheral retina were significantly decreased, with statistical significance (P＜0.05). At the age of 4 and 6 months, the density of retinal cone cells (F=127.30) and b-wave photopic amplitude (F=51.13) in the control group were significantly decreased, and the difference was statistically significant (P＜0.05). Immunofluorescence microscopy showed that the NSC transplanted in the experimental group preferentially differentiated into astrocytes, and stably expressed CNTF and GDNF at high levels. Comparison of retinal photoreceptor nucleus lines in different treatment subgroups of the experimental group at different ages: CNTF-NSC group, at 2 months of age: the whole, central and peripheral regions were significantly different (F=31.73, 75.06, 75.06; P＜0.05); 4 months of age: The difference between the whole area and the peripheral region was statistically significant (F=12.27, 12.27; P＜0.05). GDNF/CNTF-NSC group, 2 and 4 months of age: the whole (F=27.26, 27.26) and the peripheral area (F=16.01, 13.55) were significantly different (P＜0.05). In GDNF-NSC group, there was no statistical significance at all in the whole, central and peripheral areas at different months of age (F=0.00, 0.01, 0.02; P＞0.05). ConclusionsCLN7 neuronal ceroid-lipofuscinosis mice exhibit progressively increasing degenerative alterations in photoreceptor cells and bipolar cells with age growing, aligning with both morphological and functional observations. Intravitreal administration of stem cell-based CNTF as well as GDNF/CNTF show therapeutic potential in rescuing photoreceptor cells. Nevertheless, the combined application of GDNF/CNTF-NSC do not demonstrate the anticipated synergistic protective effect. GDNF has no therapeutic effect on the retinal morphology and function in CLN7 neuronal ceroid-lipofuscinosis mice.
Age-related macular degeneration (AMD) is an age-related neurodegenerative eye disease characterized by degeneration of retinal pigment epithelium (RPE) cells, photoreceptor cells, and progressive death. Stem cell therapy is a new treatment for AMD in recent years, and it is a research hotspot. Although there are risks such as increased incidence of cancer and immune rejection in stem cell therapy, retinal cells such as RPE cells are derived from stem cells, and neurotrophic factors and extracellular vesicles produced by stem cells can significantly repair damaged photoreceptors and retinal cells. The cryopreservation method of embryonic stem cell-derived RPE cells and the vigorous development of delivery technologies such as plasmids, adeno-associated viruses and Sendai virus have also laid a solid foundation for stem cell therapy of AMD. Stem cell neuroprotective therapy is being used as a new method to prevent retinal damage and photoreceptor degeneration, which will provide new ideas for the prevention and treatment of AMD in the future.