PURPOSES:To investigate the time of neuronie apoptosis in the retinas of Imman fetuses,and its relations with neuronie proliferation and differentiation, METHODS:The retinas of 27 human fetuses from 8th to 38th week of R,~til- ization age and 3 adults were studied by TdT-mediated dUTP nick end labelling(TUNEL) method. RESULTS:Tbe nuctei of labeled apoptotic cells were charaeterised by nuclear marginization,ehromatln condensation and cleseent shape,and some apoptotie bodies were visible in the specimens. The apoptosis of neuroepithelium of fetal rclina took place during 8th to 18th week, Apoptosis of ganglion cells were observed from 1256 to 18th week. The apoptos[s of pholorec, plors were formd from 14th to 2Ist week ,while thai of bipolar neurones and M~ller cells were found from ldth to 28th week. No apoptosb of ocstones were observed in the retinas after 28th week of fertilization age and within the retinas of adults. CONCLUSION:The proliferating cells of neuroepithelium and Ihe neurones which just differetiated from fetal retina might partly undergo apoptosis. The time of apoptosls of differentiated neurones was consistent with the time of the synapses formation between neurones and their targel cells. （Chin J Ocul Fundus Dis,1997,13:67 -69 ）
Objective To explore the method that can inducethe mesenchymal stem cells (MSCs) to differentiate into the neuronlike cells in vitro．Methods The neuron-like cells were isolated froman SD rat (age, 3 months; weight, 200 g). They underwent a primary culture; theinduced liquid supernatant was collected, and was identified by the cell immunohistochemistry. The C3H1OT1/2 cells were cultured, as an MSCs model, and they were induced into differentiation by β-mercaptoethanol (Group A) and by the liquid supernatant of the neuron-like primary cells (Group B), respectively. The cells were cultured without any induction were used as a control (Group C). Immunohistochemistrywas used to identify the type of the cells． Results The result of the immunochemistry showed that the cells undergoing the primary culture expressed the neurofilament protein (NF) and the neuronspecific enolase (NSE), and they were neuron-like cells. β-mercaptoethanol could induce the C3H1OT1/2 cells toexpress NF and NSE at 2 h, and the expression intensity increased at 5 h. The liquid supernatant of the primarily-cultured neuron-like cells could induce theC3H1OT1/2 cells to express NF and NSE at 1 d, but the expression intensity induced by the liquid supernatant was weaker than that induced by β-mercaptoethanol. The positivity rate and the intensity expression of NSE were higher than those of NF. Conclusion MSCs can differentiate into the neuron-like cells by β-mercaptoethanol and the microenvironment humoral factor, which can pave the way for a further study of the differentiation of MSCs and the effectof the differentiation on the brain trauma repair.
Objective To review the possible mechanisms of the mammal ian target of rapamycin (mTOR) in theneuronal restoration process after nervous system injury. Methods The related l iterature on mTOR in the restoration ofnervous system injury was extensively reviewed and comprehensively analyzed. Results mTOR can integrate signals fromextracellular stress and then plays a critical role in the regulation of various cell biological processes, thus contributes to therestoration of nervous system injury. Conclusion Regulating the activity of mTOR signaling pathway in different aspects cancontribute to the restoration of nervous system injury via different mechanisms, especially in the stress-induced brain injury.mTOR may be a potential target for neuronal restoration mechanism after nervous system injury.
ObjectiveTo observe the effect of integrin β8 on the neuronal apoptosis after hypoxia ischemia (HI) in astrocyte/neuron co-culture system. MethodsAstrocytes and neurons were cultured in vitro from cerebral cortex of the P1-3 days Sprague Dawley rats and E16 days fetal rats, respectively. Immunocytochemistry staining was used to identify the purity of cells. Integrin β8 mRNA expression was qualified in the astrocytes at 12 hours, 1 day, and 2 days after HI and reoxygenation (experimental group) and in normal astrocytes (control group) by RT-PCR. Integrin β8 small interering RNA (siRNA) system was established to specifically block astrocyte β8 expression, the efficiency of integrin β8 inhibition was detected by real-time fluorescent PCR. The astrocytes and neurons were co-cultured to established the astrocyte/neuron co-culture system. The neuronal apoptosis was detected with TUNEL in the normal neurons/astrocytes group (co-cultured HI group), the astrocytes infected by integrin β8 siRNA for 2 days/normal neurons group (β8 RNA interference group), and normal neurons in vitro with HI treatment group (HI group) at 1 day after HI and reoxygenation. The normal neurons without treatment as control (control group). ResultsGlial fibrillary acidic protein and neuronal nuclei staining suggested a purity of more than 90% in cultured cells. HI resulted in an increase of integrin β8 mRNA expression at 12 hours after reoxygenation in astrocytes, which peaked at 1 day after reoxygenation, then slowly decreased and remained higher at 2 days, showing significant differences between control group and experimental group and among different time points in experimental group (P<0.05). RNA interference efficiency was most significant at 2 days after astrocytes infected with integrin β8 siRNA (P<0.05). The neuronal apoptosis was significantly increased in HI group, co-cultured HI group, and β8 RNA interference group when compared with control group (P<0.05). But neuronal apoptosis index (AI) was significantly decreased in co-cultured HI group and β8 RNA interference group when compared with HI group (P<0.05). The significant difference of AI was found between co-cultured HI group and β8 RNA interference group (P<0.05). ConclusionIntegrin β8 expression can be induced with hypoxic-ischemic brain damage, leading to decreased AI of neurons and obvious protective effect.
Objective To evaluate the prognostic value of the level of serum neurone specific enolase (NSE) in patients with small cell lung cancer (SCLC). Methods We searched MEDLINE, EMbase, CBMdisc, and The Cochrane Central Register of Controlled Trials (1950 to December 2007). Studies meeting the eligibility criteria were retrieved and their bibliographies were checked for other relevant publications. The quality of included studies was evaluated by 2 reviewers independently. Meta-analyses were performed for the results of homogeneous studies using STATA 7.0 software. Results Nine studies involving 2 021 SCLC patients were included. About 66.0% of patients had high serum levels of NSE, according to the cut-off value defined by the authors. The hazard ratio (HR) of high levels of NSE for overall survival (OS) was 1.27 times of that of low levels of NSE for OS in SCLC patients (95% CI 1.19 to 1.35, P=0.281). Conclusion Patients with high levels of NSE appear to have a poorer OS compared with those with low levels of NSE, thus the level of NSE has a prognostic value in SCLC patients. Due to the potential publication bias, selection bias, and measurement bias among these studies, the conclusion should be interpreted carefully. More high-quality homogeneous studies are required to accurately evaluate the prognostic value of NSE.
OBJECTIVE: To research the protective effect of Schwann cell and extracellular matrix (ECM) gel on neurons in dorsal root ganglion. METHODS: 1. Schwann cells were seeded into 30% ECM at 1 x 10(8)/ml and then implanted into PLA hollow fiber conduits to repair 10 mm length defects of rat sciatic nerve, and histological observation was taken at 8 and 12 weeks after operation. 2. To observe the survival of Schwann cells, Schwann cells labeled BrdU were seeded into 30% ECM at 1 x 10(8)/ml and then implanted into PLA hollow fiber conduits to repair 10 mm length defects of rat sciatic nerve. Histological observation and immunohistochemical method stained with BrdU were done at 3 and 6 weeks after operation. RESULTS: 1. When seeded into ECM gel and transplanted into rats, most of the Schwann cells survived to 3 weeks and a part of them survived up to 6 weeks. 2. The survival neuron ratios of Schwann cells with ECM gel group and ECM gel group were 83.5% and 81.3% respectively, and significantly higher than that of saline group (72.9%, P lt; 0.05). CONCLUSION: When seeded into ECM gel and transplanted into rats, most of the Schwann cells survive and protect 83.5% neurons in dorsal root ganglion from retrograde death.
Objective To observe the effects of minocycline to the viability and apoptosis of ratprime;s retinal neuron cells (RNC) under pressure, and to investigate the neuroprotective mechanisms of minocycline against the RNC damage. Methods Establish a model of ratprime;s RNs under pressure cultured in vitro, the protective effect of minocycline is observed by different methods, including observing the morphology of the cells, evaluating the cellsprime; viability by methyl thiazolyl tetrazolium (MTT) colorimetry assay, and detecting the cellular apoptosis with acridine orange/ethidium bromide (AO/EB) double staining by fluorescence microscopy. Immunocytochemistry was used to detect the expression of iNOS and caspase-3 in the cells. Results Obvious morphology changes of RNC were found in cells under pressure compared with the control; the viability of RNC decreased and cellular apoptosis was found in 53.93% cells. The cellular morphology improved in the cells treated by 20 mu;mol/L minocycline, the cellular viability significantly increased, and the cellular apoptosis was found in 17.29% cells. In addition, the expression of iNOS and caspase3 in the treated cells decreased compared with which in the pressured group. Conclusion Minocycline with a certain concentration can effectively inhibit pressureinduced damage and apoptosis of RNC of rats, and the inhibitory effect on expression of iNOS and capases-3 may be the underlying mechanism.
Objective To investigate the influence of diammonium glycyrrhizinate (DG) on the expression of NF-κB and neuron apoptosis after spinal cord ischemia-reperfusion injury in rats. Methods Fourty-eight healthy SD male rats, weighing 220-270 g, were randomly divided into the experimental group and the control group, with 24 rats in each group. A model of spinal cord ischemia-reperfusion injury was completed by intercepting the rats’ abdominal aorta between right and left renal arteries for 30 minunts. In the experimental group, each rat was injected 20 mg/kg DG via subl ingual vein 10 minutes before ischemia occurred. Equal qual ities of physiological sal ine were injected into the rats in the control group. The two groups were observed at 3, 24, 72 and 168 hours after ischemia-reperfusion, respectively. Lumbar myeloid tissues were prepared at the different times, respectively. The expression of NF-κB p65 in lumbar myeloidtissues was analyzed by immunohistochemistry and the apoptosis of neurons was examined by TUNEL reaction. Meanwhile, histological changes of spinal cord were observed by HE staining. Then the correlation between NF-κB and neuron apoptosis was analyzed. Results HE staining showed obvious histological changes of spinal cord of the two groups. In the control group, myeloid tissue edema and normal neurons were observed at 3 hours; there were more histological changes at 24 hours and 72 hours; vacuolus in gray matters and some survived neurons were seen at 168 hours. The histological changes at each time in the experimental group were fewer than those in the control group. The immunohistochemical staining showed that the expression of NF-κB p65 was observed. After ischemia-reperfusion, the expression strengthened at 3 hours, reached the peak at 24 hours and then weakened slowly. At 3, 24, 72 and 168 hours after ischemia-reperfusion, the absorbency (A) value of NF-κB p65 in the experimental group was 0.306 0 ± 0.024 4, 0.396 4 ± 0.022 7, 0.296 6 ± 0.021 1 and 0.267 9 ± 0.015 3, respectively, and that in the control group was 0.361 1 ± 0.017 7, 0.496 6 ± 0.020 1, 0.356 3 ± 0.021 0 and 0.301 4 ± 0.018 1, respectively. There were significant differences between the two groups (P lt; 0.05). The inhabitation ratio of NF- κB p65 expression by DG was 15.40%, 20.17%, 19.28% and 11.11% at 3, 24, 72 and 168 hours after ischemia-reperfusion, respectively. Neuron apoptosis was observed, which strengthened at 3 hours and was the most serious at 24 and 168 hours after ischemia-reperfusion. At 3, 24, 72 and 168 hours after ischemia-reperfusion, the A value of neuron apoptosis in the experimental group was 0.171 0 ± 0.029 1, 0.175 5 ± 0.031 1, 0.175 1 ± 0.027 9 and 0.183 2 ± 0.023 7, respectively, and that in the control group was 0.236 8 ± 0.063 6, 0.241 2 ± 0.042 6, 0.201 5 ± 0.049 8 and 0.250 1 ± 0.048 4, respectively. There were significant differences between the two groups (P lt; 0.05). The inhabitation ratio of neuron apoptosis by DG was 27.79%, 27.23%, 13.08% and 26.74% at 3, 24, 72 and 168 hours after ischemia-reperfusion, respectively. The expression of NF-κB in myeloid tissues was positively correlated with neurons apoptosis in the two groups (r = 0.838, P lt; 0.01). Conclusion Spinal cord ischemia-reperfusion injury may cause a marked expression of NF-κB and notable evidence of neurons apoptosis. DGcan reduce neurons apoptosis by inhibiting the expression of NF-κB.
Objective To investigate the possibility of commitment differentiation of embryonic stem cells induced by the medium of cultured retinal neurons of SD rats. Methods The medium from cultured retinal neurons of SD rats were collected, sterilized and mixed with DMEM medium according to 2∶3 proportion, ES cells were cultured with these mixed medium and were observed under the phase contrast microscope daily, the induced cells were identified by NF immunohistochemistry methods. Results The ES cells cultured with these mixed medium can differentiate into neuron-like structure, and the induced cells were positive in NF immunofluorescence staining. Conclusion The medium from cultured retinal neurons of SD rats can induce ES cells commitment differentiation into neuron-like structure. (Chin J Ocul Fundus Dis, 2002, 18: 134-136)
Objective To study the expression and its significance of bcl-2 associated death (bad) gene in human optic nerves from traumatic atrophic eyeballs. Methods The optic nerves from 8 normal human donor eyes and 31 traumatic atrophic eyes were studied by immunohistochemistry technique. Results Bad protein was positively expressed in the normal optic nerve myelin sheath and residual myelin portions of optic nerve tissues from traumatic atrophic eyes. The expression of bad protein in the residual portions of myelin sheath was stained significantly ber than that in normal optic nerves (P＜0.05)。The pathological durations for ocular atrophy was not co-related with the quantites of expression of bad protein. There was no significant difference between pathogenic causes of ocular atrophies and the quantites of bad expression (P＞0.05). Conclusion Bad might possess the function of promoting the optic nerve atrophy processes in traumatic atrophic eyes. (Chin J Ocul Fundus Dis, 2002, 18: 276-278)