OBJECTIVE: To study the nerve growth factor (NGF) expression and the influence of IL-1 alpha or IL-1 beta on NGF secretion in newborn rat astrocytes. METHODS: Astrocytes obtained from the brain cortex of newborn rats were cultured and purified, and they were divided into three groups, experimental, control and blank groups. IL-1 alpha or IL-1 beta were added into the experimental group with 25, 50 and 100 U/ml, each group was cultured for 24, 48 or 72 hours, and then the NGF contents in cultured astrocytes suspension media were measured by a two-cite enzymelinked immunoserbent assay (ELISA). RESULTS: Astrocytes could secret NGF by themselves and each concentration of IL-1 alpha or IL-1 beta media at any testing time could enhance NGF secreting in newborn rat astrocytes in certain degrees. The effects of IL-1 beta were ber than IL-1 alpha, the best effect in the unit time was observed in IL-1 beta with 50 U/ml for 24 hours. CONCLUSION: Astrocytes can express NGF, and IL-1 alpha or IL-1 beta can enhance the NGF expression in newborn rat astrocytes.
Objective Telomerase reverse transcriptase (TERT) is the key factor to determine cell growth and l ifespan. Meanwhile, it is tightly related to resistance of cell to stress and apoptosis. However, up till now l ittle is known about the role TERT plays in nervous system. To investigate the effect of conditioned medium from astrocytes (AS) transfected with TERT on neurons subjected to hypoxia-ischemia-reperfusion (HI-RP) through construction of in vitro HI-RP model of neurons. Methods An eukaryote expression plasmids containing rat full length TERT gene was constructed as pcDNA3-TERT. Twenty newborn rats at age of 3 days were sacrificed and their cerebral cortex were collected for isolation and cultivationof AS. Then AS were transfected with pcDNA3-TERT through l iposomes mediation, and positive clones were selected by G418 and expanded for continuous culture to establ ish the plamid pcDNA3-TERT transfection group. Meanwhile, the empty plasmid pcDNA3 transfection group and the non-transfection group were establ ished as control. The expression of gl ial fibrillary acidic protein (GFAP), which was the specific marker of the AS, was detected by immunocytochemistry, as well as the expression of TERT. Astrocyte conditioned medium (ACM) of the plamid pcDNA3-TERT transfection group was collected as TERT-ACM, while the ACM of the empty plasmid pcDNA3 transfection group and the non-transfection group were collected respectively as p-ACM and ACM. Next, 60 rats at age of 1 day were sacrificed and their cerebral cortex were collected for isolation and cultivation of neurons. The neurons were randomly divided into experimental group and normal group, the experimental group were further divided into 4 groups including control group, ACM group, p-ACM group, and TERT-ACM group. The neurons of control group were subjected to HI damage in serum-free DMEM, and the neurons of ACM group, p-ACM group, and TERTACM group were subjected to HI damage in different medium which contained ACM, p-ACM, and TERT-ACM, respectively. After duration of HI for 3 hours under the environment with 5%CO2, 1%O2, and 94%N2; the neurons of experimental groups were placed in CO2 incubator to imitate RP for 3, 6, 18, 24, and 36 hours in vitro. The neurons of normal group were not subjected to HI and RP treatment. During the treatment of HI-RP, the survival ratio of neurons was detected by means of MTT, the lactate dehydrogenase (LDH) activity of neuron medium with LDH detection kit, and the neuronal apoptosis by means of TUNEL. Results The percentages of GFAP positive cells were 98%, 99%, and 98% in non-transfection group, plasmid pcDNA3-TERT transfection group, and plasmid pcDNA3 transfection group, respectively. There was no expression of TERT in no-transfection group and plasmid pcDNA3 transfection group, and the percentage of TERT positive cells in plasmid pcDNA3- TERT transfection group was 98%. Compared with normal group, the survival ratio of ......（余见正文）
Neuropathic pain has been redefined by NeuPSIG as “pain arising as a direct consequence of a lesion or disease affecting the somatosensory syste”. However, pharmacological management for neuropathic pain is not effective, which is correlated with the uncertainty of pathogenesis. For a long time, neuron had been considered acting a major role in the development of neuropathic pain. In recent years, a majority of studies revealed that glia cell also involved in the occurrence and development of neuropathic pain, and neuron-glia interaction is one of the key mechanism of neuropathic pain, including complex signaling pathways as purinergic signaling. This review focuses on recent advances on the role of purinergic receptors in neuropathic pain.
Developmental and epileptic encephalopathy (DEE) is a genetic neurological disease affecting 0.27–0.54 per 1000 newborns, with a strong genetic association. Currently, the majority of known pathogenic genes in genetic DEE can be classified into six functional categories: ion channels, organelles and cell membranes, growth and development, synaptic function, neurotransmitters and receptors, DNA and RNA regulation, and signal transduction pathways. Emerging evidence suggests that inflammatory regulation may play a critical role in genetic DEE pathogenesis. Specifically, astrocyte and microglial activation contributes to neuroinflammation in genetic DEE, while pro-inflammatory cytokines disrupt neuron-glia interactions, exacerbating epileptic seizures and neuronal damage. Targeting the source mechanism of neuroinflammation in genetic DEE, such as the activation of astrocytes and microglia, and intervening from the source, is expected to be a new target for the treatment of genetic DEE.
目的:观察体外培养星形胶质细胞损伤后S100β的表达变化,进一步了解脑损伤修复的分子机制,以期为法医病理学鉴定提供更多的依据。方法:取出生后24h内SD大鼠大脑皮质进行星形胶质细胞体外分离培养和纯化。随机分为对照组和损伤后30min、1h、3h、6h、12h、24h、3d、7d组,应用ABC法检测不同时间段S100β表达的差异。结果:体外培养星形胶质细胞的纯度达95％以上。对照组可见少量S100β蛋白表达;损伤后30min,S100β开始增加,3~6h达高峰,随后下降,24h时低于对照组水平,此后略有上升,7d时恢复至对照组水平。结论: 机械性划痕损伤后S100β总体表达呈单峰,而在体动物实验结果表明大鼠大脑损伤后S100β总体表达成双峰趋势,但均具有时序性变化规律,说明损伤后S100β表达可为脑损伤时间的推断依据之一;体外培养细胞损伤模型对组织细胞损伤的分子机制研究具有优越性。
Objective To investigate the division, prol iferation and differentiation abil ities of nestin+/GFAP+cell after spinal cord injury and to identify whether it has the characteristic of neural stem cells (NSCs). Methods Twelvemale SD rats, aged 8 weeks and weighing 200-250 g, were randomized into 2 groups (n=6 per group): model group inwhich the spinal cord injury model was establ ished by aneurysm cl ip compression method, and control group in which no processing was conducted. At 5 days after model ing, T8 spinal cord segment of rats in each group were obtained and the gray and the white substance of spinal cord outside the ependymal region around central tube were isolated to prepare single cellsuspension. Serum-free NSCs culture medium was adopted to culture and serum NSCs culture medium was appl ied to induce differentiation. Immunohistochemistry detection and flow cytometry were appl ied to observe and analyze the type of cells and their capabil ity of division, prol iferation and differentiation. Results At 3-7 days after injury, the model group witnessed a plenty of nestin+/GFAP+ cells in the single cell suspension, while the control group witnessed few. Cell count of the model and the control group was 5.15 ± 0.71 and 1.12 ± 0.38, respectively, indicating there was a significant difference between two groups (P lt; 0.01). Concerning cell cycle, the proportion of S-phase cell and prol iferation index of the model group (15.49% ± 3.04%, 15.88% ± 2.56%) were obviously higher than those of the control group (5.84% ± 0.28%, 6.47% ± 0.61%), indicating there were significant differences between two groups (P lt; 0.01). In the model group, primary cells gradually formed threedimensional cell clone spheres, which were small in size, smooth in margin, protruding in center and positive for nestin immunofluorescence staining, and large amounts of cell clone spheres were harvested after multi ple passages. While in the control group, no obvious cell clone spheres was observed in the primary and passage culture of single cell suspension. At 5 days after induced differentiation of cloned spheres in the model group, immunofluorescence staining showed there were a number of galactocerebroside (GaLC) -nestin+ cells; at 5-7 days, there were abundance of β-tubul in III-nestin+ and GFAP-nestin+ cells; and at 5-14 days, GaLC+ ol igodendrocyte, β-tubul in II+ neuron and GalC+ cell body and protruding were observed. Conclusion Nestin+/GFAP+ cells obtained by isolating the gray and the white substance of spinal cord outside the ependymal region around central tube after compressive spinal cord injury in adult rat has the abil ity of self-renewal and the potential of multi-polarization and may be a renewable source of NSCs in the central nervous system.
ObjectiveTo explore the biological functions of Kip1 ubiquitylation-promoting complex 2 (KPC2) in the repair process of spinal cord injury (SCI) by studying the expression and cellular localization of KPC2 in rat SCI models. MethodsFifty-six adult Sprague-Dawley rats were randomly divided into 2 groups: in the control group (n=7), simple T9 laminectomy was performed;in the experimental group (n=49), the SCI model was established at T9, 7 rats were used to detect follow indexs at 6 hours, 12 hours, 1 day, 3 days, 5 days, 7 days, and 14 days after SCI. Western blot analysis was used to detect the protein expressions of P27kip1, KPC2, CyclinA and proliferating cell nuclear antigen (PCNA) after SCI. Immunohistochemistry was used to observed the cellular localization of KPC2 after SCI, double-labeling immunofluorescence staining to observe the co-localization of KPC2 with neuronal nuclei (NeuN), glial fibrillary acidic protein (GFAP) and PCNA. in vitro astrocytes proliferation model was used to further validate these results, Western blot to detect KPC2, P27kip1, and PCNA expressions. The interaction of P27kip1, KPC1, and KPC2 in cell proliferation was analyzed by co-immunoprecipitation. ResultsThe Western blot analysis showed a significant down-regulation of P27kip1 and a concomitant up-regulation of KPC2, CyclinA, and PCNA after SCI. Immunohistochemistry staining revealed a wide distribution of KPC2 positive signals in the gray matter and white matter of the spinal cord. The number of KPC2 positive cells in the experimental group was significantly higher than that in the control group (t=10.982, P=0.000). Double-labeling immunofluorescence staining revealed the number of KPC2/NeuN co-expression cells in the gray matter of spinal cord was (0.43±0.53)/visual field in the control group and (0.57±0.53)/visual field in the experimental group, showing no significant difference (t=0.548, P=0.604);in the white matter of spinal cord, the number of KPC2/PCNA co-expression cells was (3.86±0.90)/visual field in the control group and (0.71±0.49)/visual field in the experimental group, showing significant difference (t=7.778, P=0.000). And then, the number of KPC2/PCNA co-expression cells were (0.57±0.53)/visual field in the control group and (5.57±1.13)/visual field in the experimental group, showing significant difference (t=8.101, P=0.000). Concomitantly, there was a similar kinetic in proliferating astrocytes in vitro. The Western blot analysis showed a significant down-regulation of P27kip1 and a concomitant up-regulation of KPC2 and PCNA after serum stimulated. Co-immunoprecipitation demonstrated increased interactions between P27kip1, KPC1, and KPC2 after stimulation. ConclusionThe up-regulated expression of KPC2 after SCI is related to the down-regulation of P27kip1, this event may be involved in the proliferation of astrocytes after SCI.
Objective To investigate the effect of M2 microglia (M2-MG) transplantation on spinal cord injury (SCI) repair in mice. Methods Primary MG were obtained from the cerebral cortex of 15 C57BL/6 mice born 2-3 days old by pancreatic enzyme digestion and identified by immunofluorescence staining of Iba1. Then the primary MG were co-cultured with interleukin 4 for 48 hours (experimental group) to induce into M2 phenotype and identified by immunofluorescence staining of Arginase 1 (Arg-1) and Iba1. The normal MG were harvested as control (control group). The dorsal root ganglion (DRG) of 5 C57BL/6 mice born 1 week old were co-cultured with M2-MG for 5 days to observe the axon length, the DRG alone was used as control. Forty-two 6-week-old female C57BL/6 mice were randomly divided into sham group (n=6), SCI group (n=18), and SCI+M2-MG group (n=18). In sham group, only the laminae of T10 level were removed; SCI group and SCI+M2-MG group underwent SCI modeling, and SCI+M2-MG group was simultaneously injected with M2-MG. The survival of mice in each group was observed after operation. At immediate (0), 3, 7, 14, 21, and 28 days after operation, the motor function of mice was evaluated by Basso Mouse Scale (BMS) score, and the gait was evaluated by footprint experiment at 28 days. The spinal cord tissue was taken after operation for immunofluorescence staining, in which glial fibrillary acidic protein (GFAP) staining at 7, 14, and 28 days was used to observe the injured area of the spinal cord, neuronal nuclei antigen staining at 28 days was used to observe the survival of neurons, and GFAP/C3 double staining at 7 and 14 days was used to observe the changes in the number of A1 astrocytes. Results The purity of MG in vitro reached 90%, and the most of the cells were polarized into M2 phenotype identified by Arg-1 immunofluorescence staining. M2-MG promoted the axon growth when co-cultured with DRGs in vitro (P<0.05). All groups of mice survived until the experiment was completed. The hind limb motor function of SCI group and SCI+M2-MG group gradually recovered over time. Among them, the SCI+M2-MG group had significantly higher BMS scores than the SCI group at 21 and 28 days (P<0.05), and the dragging gait significantly improved at 28 days, but it did not reach the level of the sham group. Immunofluorescence staining showed that compared with the SCI group, the SCI+M2-MG group had a smaller injury area at 7, 14, and 28 days, an increase in neuronal survival at 28 days, and a decrease in the number of A1 astrocytes at 7 and 14 days, with significant differences (P<0.05). ConclusionM2-MG transplantation improves the motor function of the hind limbs of SCI mice by promoting neuron survival and axon regeneration. This neuroprotective effect is related to the inhibition of A1 astrocytes polarization.