Expression of NF-kB in Schwann apoptosis in spinal cord following cells and its effect on motor neuron sciatic nerves injury in rats

Objective：To explore the expression of nuclear factor-kappa B （NF-kB） in Schwann cells （SCs） and its effect on motor neuron apoptosis in spinal cord following sciatic nerves injury in adult rats. Methods： Thirty-six adult Sprague-Dawley （SD） rats were divided randomly into normal control group （n=6）, and sciatic nerves crushing group （n= 30）, and the later was further equally randomized into 5 subgroups： 1, 3, 7, 14, and 21 d post-injury groups. The expression of NF-kB of normal and injured nerves were examined by immunohistochemistry staining, and the apoptosis of motor neurons in spinal cord of lumbar 4 to lumbar 6 （L4-L6） was investigated by terminal deoxynucleotidyl transferase mediated dUTP-biotin nick end labeling （TUNEL） assay. Both were qua.ntitated by image analysis. Results： In crushing group, except 21 d post-injury group, the expression of NF-kB was markedly higher than that in the normal control group （P〈0.05, P〈0. 01）. At 1 d after sciatic nerves crushing, the expression of NF-kB was obviously up-regulated, reached peak at 3 d, and recovered at 21 d. The same trend was observed in the time-course on motor neuron apoptosis after sciatic nerves injury. Correlation analyses revealed that motor neuron apoptosis was significantly and positively correlated with the expression of NF-kB following sciatic nerves injury （r= 0. 976 0, P〈0. 01）. Conclusion： After injury of sciatic nerves, the presence and up-regulation of NF-kB in SCs may be involved in motor neuron apoptosis in L4-L6 spinal cord.     

Survival and migration of Schwann cells after the vascularized peripheral nerve grafted into spinal cord in rats

Objective：To study the survival and ability of inducing axonal regeneration of the Schwann cells after the peripheral nerve being grafted into spinal cord. Methods：A total of 30 adult female Wistar rats were randomly divided into the VN （vascularized peripheral nerve） and PN （peripheral nerve） groups. A 5-mm spinal cord defect of the left posterior column was made at the T1-3 vertebral level. The defect was grafted with the vascularized or isolated peripheral nerve respectively. The survival and proliferation of the Schwann cells were assessed by histological and morphometric analysis 8 weeks after the operation. Resuits：In the VN group, the peripheral nerve grew into the cord with lots of Schwann cells survived and proliferated, and had more NF and S-100 positive fibers than in the PN group. Conclusion：The vascularized peripheral nerve enhances the survival and proliferation of the Schwann cells and prompts the regener- ation of injured axon of the central nerve system to certain degree.     

Effect of neurotrophin-3 on SOD and MDA in rats after acute spinal cord injury

Objective：To investigate the effect of neurotrophin-3 on the expressions of SOD and MDA in the injured spinal cord of rats. Methods： Totally 105 SD rats were randomly divided into 3 groups （n= 35）： sham group, control group and experimental group. Animal model of acute spinal cord was inflicted with Allen＇s method by a thin plastic tube situated in subarachnoid space below the injury level for perfusion. Rats in experimental group received 20μl NT-3 （200ng） from the tube at 0, 4, 8, 12, 24 h and 3, 7 d after injury, and those in control group got the equal volume of normal saline at the same time points. The animals in sham group only received opening vertebral plate and putting tube in subarachnoid space. The rats were sacrificed at 4, 8, 12, 24 h, and 3, 7, 14 d postinjury （n=5）. And the levels of superoxide dismutase （SOD） and malondialdehyde （MDA） in blood were observed with colorimetric method. Results： The serum level of SOD reduced obviously and the level of MDA raised obviously in rats after the injury, and the activity of SOD reached the lowest on day 3 and the concentration of MDA reached peak at the 7 d. In the experimental group, the SOD level was obviously higher （P〈0. 01）, and MDA level was lower than the control （P〈0. 01）. Conclusion： NT-3 can mitigate secondary injury of spinal cord in vivo. One of mechanisms is that inhibits abnormal expression of MDA and elevates the activity of SOD, thus the injury of free radical and lipid peroxidation is attenuated.     

Influence of neurotrophin-3 on Bcl-2 and Bax expressions in spinal cord injury of rats

Objective： To study the protective mechanisms of neurotrophin-3 （NT-3） on the spinal cord injury. Methods：Totally 105 SD rats were randomly divided into 3 groups： control group, experimental group and sham operation group. Rats from the former 2 groups were inflicted to animal model of acute spinal cord injury according to Allen＇s （WD） by situating a thin plastic tube in the subarachnoid space below the injury level for perfusion. Rats in experimental group received 20 ul NT-3 （200 ng） from the tube at 0, 4, 8, 12, 24 h and 3, 7 d after injury, and those in control group got an equal volume of normal saline at the same time. The animals in sham operation group only received opening vertebral plate and tube was put in subarachnoid space. The rats were sacrificed at 4, 8, 12, 24 h and 3, 7, 14 d post injury （n=5）. The expression levels of Bcl-2 and Bax proteins in spinal cord of rats were detected by immunohistochemistry assay. Results： The level of Bax protein in control group significantly increased as compared with those in sham operation group, and the peak reached at 8 h after spinal cord injury. The Bcl-2 proteins were always weakly positive. The Bax proteins in NT-3 group significantly decreased but the Bcl-2 proteins obviously increased as compared with those in control group. Conclusion： NT-3 can protect spinal cord from injury in vivo. One of the mechanisms is that NT-3 can inhibit abnormal expression of Pax protein, and increase the expression of Bcl-2 protein, then inhibit apoptosis after spinal cord injury.     

The effects of ciliary neurotrophic factor on neurological function and glial activity following contusive spinal cord injury in the rats

Ciliary neurotrophic factor (CNTF) has been implicated in the pathophysiology of injury to the central nervous system. The rapid increase in CNTF production following spinal cord injury (SCI) in rats is thought to serve a role in the neuronal survival and functional recovery. In this study, 40 SD rats were divided into four groups.- sham-     

Transplantation of human amniotic epithelial cells improves hindlimb function in rats with spinal cord injury

Background Human amniotic epithelial cells (HAECs), which have several characteristics similar to stem cells, therefore could possibly be used in cell therapy without creating legal or ethical problems. In this study, we transplanted HEACs into the injured spinal cord of rats to investigate if the cells can improve the rats’ hindlimb motor function. Methods HAECs were obtained from a piece of fresh amnion, labeled with Hoechst33342, and transplanted into the site of complete midthoracic spinal transections in adult rats. The rats (n=21) were randomly divided into three groups: Sham-operation group (n=7), cells-graft group (n=7), and PBS group (n=7). One rat of each group was killed for histological analysis at the second week after the transplantation. The other six rats of each group were killed for histological analysis after an 8-week behavioral testing. Hindlimb motor function was assessed by using the open-field BBB scoring system. Survival rate of the graft cells was observed at second and eighth weeks after the transplantation. We also detected the myelin sheath fibers around the lesions and the size of the axotomized red nucleus. A one-way ANOVA was used to compare the means among the groups. The significance level was set at P<0.05.Results The graft HAECs survived for a long time (8 weeks) and integrated into the host spinal cord without immune rejection. Compared with the control group, HAECs can promote the regeneration and sprouting of the axons, improve the hindlimb motor function of the rats (BBB score: cells-graft group 9.0±0.89 vs PBS group 3.7±1.03, P<0.01), and inhibit the atrophy of axotomized red nucleus [cells-graft group (526.47±148.42) µm(2 )vs PBS group (473.69±164.73) µm(2), P<0.01]. Conclusion Transplantation of HAECs can improve the hindlimb motor function of rats with spinal cord injury.     

Effect of platelet activating factor on blood spinal cord barrier following cervical cord injury

Bloodspinalcordbarrierdamagefollowingcervicalcordinjuryplaysanimportantroleinthepathophysiologicalprocessofsecondarybleeding,edemaandnecrosisofcervicalcordtissue-Plateletactivatingfactor(PAF)isaverystrongbiologicalactivatinglipidmediator-Inrecentyears,interesthasbeenfocusedontheroleofPAFinbloodbrainbarrierdisruption'IthasbeenprovedthatPAFplaysanimportantroleininducingthepathologicalprocessofstrokeLlj.ThestudyoftherelationshipbetweenPAFandbloodspinalcordbarrierisrarelyreported.Inthepresen…     

Nestin expression and proliferation of ependymal cells in adult rat spinal cord after injury

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Studies on the apoptosis of autonomic neuron in streptozotocin-induced diabetic rats

Objective： The aim of the study was to investigate apoptosis of the autonomic neuron in streptozotocin-induced diabetic rats, and observe the effect of intervention with nerve growth factor （NGF） on the apoptosis. Methods： A total of 29 male Sprague-Dawley rats were divided into three groups, i.e. normal control （NC, n = 12）, untreated diabetic （DM, n = 9） and diabetic treated with NGF daily of 500 μg/kg for 30 days （DM＋NGF, n = 8）. The diabetic rat models were produced by intraperitoneal injection with streptozotocin （65 mg/kg ）. Over 3 months since the diabetes were setup, the superior cervical sympathetic ganglions（SCG） and the celiac ganglions（CG） were removed and fixed with 10% paraformaldchyde. Apoptosis was measured using terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling（TUNEL）. Apoptotic index （AI） was calculated by computer image analysis system. Results： The AI of SCG and CG in DM and DM＋NGF group were significant higher than those of NC group （P 〈 0.001） respectively. There was no difference of AI of SCG and CG between DM group and DM＋NGF group （both P 〉 0.05）. Conclusion： Neuron apoptosis may contribute to the pathophysiology of diabetic autonomic neuropathy and NGF can not prevent the apoptosis of autonomic neuron in diabetic rats.     

The effect of spinal cord injury on the expression of TGF-β and TNF-α in rat articular cartilage

Objective: To observe the expression of TGF-β and TNF-α in the spinal cord injured rat model and discuss the significance of the articular cartilage metabolism. Methods: 36 SD female rats were randomly divided into 2 groups: Rats models of spinal cord injury were implemented by Allen method. T10 laminectomy was performed in the control group. Both groups of rats were killed respectively in 1w, 3w and 6w. Hematoxylin-eosin stain was given to each slice in the model group and control group. Immunohistochemical stain was applied by using ABC method in the expression of TGF-β and TNF-α. Those expressed level were performed in image analysis and statistics process. Results: TGF-β and TNF-α were mainly distributed on the surface layer of the articular cartilage, with a weak expression in control group. The expression of TNF-α in the model group was more significant than that in the control group in the 1w, and still remained an evident difference with that in control group until the 6w(P ＜ 0.05). TGF-β expression of the model group had no remarkable difference with the control group in the lw (P ＞ 0.05) and prominently became stronger at 6w(P ＜ 0.05). Conclusion: The expression of TNF-o occurred early in the development of spinal cord injury, and the expression of TGF-β became stronger with the revival of spinal neural function. Both expressions were strengthened in articular cartilage in the 3rd week.     

The effect of spinal cord injury on the expression of TGF-β and TNF-α in rat articular cartilage

Objective： To observe the expression of TGF-β and TNF-α in the spinal cord injured rat model and discuss the significance of the articular cartilage metabolism. Methods： 36 SD female rats were randomly divided into 2 groups： Rats models of spinal cord injury were implemented by Allen method. T10 laminectomy was performed in the control group. Both groups of rats were killed respectively in 1w, 3w and 6w. Hematoxylin-eosin stain was given to each slice in the model group and control group. Immunohistochemical stain was applied by using ABC method in the expression of TGF-β and TNF-α. Those expressed level were performed in image analysis and statistics process. Results： TGF-β and TNF-α were mainly distributed on the surface layer of the articular cartilage, with a weak expression in control group. The expression of TNF-α in the model group was more significant than that in the control group in the lw, and still remained an evident difference with that in control group until the 6w（P 〈 0.05）. TGF-β expression of the model group had no remarkable difference with the control group in the lw （P 〉 0.05） and prominently became stronger at 6w（P 〈 0.05）. Conclusion： The expression of TNF-α occurred early in the development of spinal cord injury, and the expression of TGF-β became stronger with the revival of spinal neural function. Both expressions were strengthened in articular cartilage in the 3rd week.     

Activation of NF-κB and its regulation on IL-6 expression during LPS-induced liver injury

Objective： To explore the kinetics of the activation of nuclear factor-kappa B （NF-κB） and its regulation of interleukin-6 （IL-6） expression during LPS induced liver injury. Methods： Kunming mice were randomly divided into 4 groups in order to observe the does effect relationship at 3h： normal saline solution （control） group, low （1 mg/kg）, middle （5 mg/kg）, and high （10 mg/kg） LPS-induced groups; 6 groups in order to observe the time-effect relationship of 5 mg/kg LPS injection： normal saline solution （control） group, 0.5, 1, 3, 5 and 8 h groups ; pyrrolidine dithiocarbamate （PDTC） intervened groups （3 h）： normal saline solution （control） group, 5 mg/kg LPS, 200 mg/kg PDTC, and 200 mg/kg PDTC＋5 mg/kg LPS groups. NF-κB activities of Kupffer cells were determined with electrophoretic mobility shift assay （EMSA） and expression levels of IL-6 were measured with enzyme-linked immunosorbent assay （ELISA）. Results： Does-effect of NF-κB activities in Kupffer cells after LPS injection 3 h： NF-κB activation could be detected in 1 mg/kg LPS group, reached the highest level in 5 mg/kg LPS group, and persisted in 10 mg/kg LPS group; time-course after 5 mg/kg LPS injection： the DNA-binding activity was observable at 0.5 h after LPS injection, increased significantly at 3 h, and persisted for at least 8 h; in addition, antioxidant PDTC could inhibit the activation of NF-κB significantly. The kinetics of IL-6 level in liver tissues during LPS-induced liver injury were that IL-6 level after 3 h of injection increased first and then reduced; the same trend was observed in the time-course on IL-6 level after LPS injection; PDTC could significantly inhibit the release of IL-6. Correlation analyses revealed that IL-6 level was significantly and positively correlated with the activation of NF-κB. Conclusion ： NF-κB in Kupffer cells can be activitied during LPS-induced liver injury to some extent, and NF-κB may have some regulation on the expression of IL-6.     

Expression and significance of IL-6 mRNA and its protein in liver after injury in rats

Thereisagraduallyincreasedinterestoninterle'ukin--6(II---6)anditbecomesahotspotofresearchbecauseofitsrelationshipwithothercytokines,itsparticipationinthesynthesisofacutephaseproteinsanditseffectsontheearlydamagesoforgansinsystemicinjury['j.ThisstudywasdesignedtoobservethedistributionandcelllocalizationofII---6andIL--6mRNAinliverafterburninjury,endotoxemiaorthecombinationofthetwoinrats1andtheeffectsofII---6onthedevelopmentofliverdamageswereinvestigated.MATERIALSANDMETHODSOnehundreda…     

Effect of continuous spinal anesthesia with ropivacaine on the ultrastructure of spinal cord and nerve roots in rats

Effect of continuous spinal anesthesia with ropivacaine on the ultrastructure of spinal cord and nerve roots in rats@孙志华$Dept Anesthesiol,Xiangya Hosp,Zhongnan Univ,Changsha 410008     

Effect of U—74389G on apoptosis and bcl—2 expression following traumatic brain injury in rats

Objective: To investigate the relationship between oxidative stress and apoptosis and bcl-2 expression fol-lowing traumatic brain injury (TBI). Methods: Male Sprague-Dawley ras were subjected to lateral fluid percussionbrain injury (FPBI) of moderate severity. U-74389G (20 mg/kg) were administered intravenously before FPBI. Theneurological functions were measured by beam-walk task (BWT) and beam-balance task (BBT). In addition to mor-phological evidence of apoptosis, TUNEL histochemistry was used to identify DNA fragmentation in situ with both lightand electron microscopic levels. The internucleosomal fragments of DNA in apoptotic cells were examined using agarose     

Immunohistochemical changes of synaptophysin in the rat spinal cord after chronic constriction injury of sciatic nerve and ketamine intervention study

Immunohistochemical changes of synaptophysin in the rat spinal cord after chronic constriction injury of sciatic nerve and ketamine intervention study@陈敏$Dept Anesthesiol,Tongji Hosp,Tongji Med Col,Huazhong Univ Sci Technol,Wuhan 430030     

Hyperbaric oxygen intervention on expression of hypoxia-inducible factor-1α and vascular endothelial growth factor in spinal cord injury models in rats

Background Hyperbaric oxygen （HBO） intervention is a main therapeutic method and the curative effect has been certified for spinal cord injury （SCI）, but the mechanisms of the neuroprotective effect of HBO on SCI remain elusive. This study aimed to observe the change in expression of hypoxia-inducible factor-1α （HIF-1α） and vascular endothelial growth factor （VEGF） after SCI at different time points and to investigate the neuroprotective mechanism of HBO on SCI in rats.