Expression of brain nuclear factor-κB (P50) in mice with traumatic brain injury after hyperbaric oxygen treatment

Objective To investigate the relation between the therapeutic effect of hyperbaric oxygen treatment and nuclear factor-κB (NF-κB) (P50) expression in the brain tissue in mice with traumatic brain injury (TBI). Methods A total of 120 SD rats were randomly divided into sham-operated, TBI model, normobaric oxygen and hyperbaric oxygen (0.2 MPa) groups, and in the latter 3 groups, TBI was induced using Feeney's method. At 6 h and 1, 3, 5, and 7 d following TBI (6 rats at each time point), the rats were sacrificed to observe the pathological changes in the brain tissues under light microscope and detect the expression of NF-κB (P50) using immunohistochemistry. Results The rats in hyperbaric oxygen group showed lessened brain edema as compared with those in TBI model and normobaric oxygen groups. Only trace amount of NF-κB (P50) expression was observed in the sham-operated group, while in the 3 groups with TBI, NF-κB (P50) expression began to increase as early as 6 h after TBI and kept increasing till reaching the peak level at 5 days. At each of the time points for observation, the expression ofNF-κB (PS0) in hyperbaric oxygen group was significantly higher than those in TBI and normobaric oxygen groups (P<0.05). Conclusion Hyperbaric oxygen treatment offers protection of the injured neural cells and promotes their repair in rats following TBI. Increased NF-κB (P50) expression in the brain tissue may serve as one of the pathways mediating the neuroprotective effect of hyperbaric oxygen treatment.     

Neuroprotective effects of recombinant human erythropoietin on facial motoneurons after facial nerve injury in rats★

BACKGROUND： Erythropoietin and recombinant human erythropoietin （rhEPO） inhibit apoptosis of motor neurons caused by spinal cord injury and brain damage in rats. However, it still remains to be shown whether rhEPO can protect facial motoneurons （FMNs） as Well. OBJECTIVE： To test the neuroprotective effects of rhEPO on injured VMNs, as well as the influence on Caspase-3 expression. DESIGN, TIME AND SETTING： Randomized, controlled, animal experiment. This study was performed at the Central Laboratory of Basic Medical College, Chongqing Medical University from January to October 2007. MATERIALS： Seventy-five female SD rats, weighing 210-230 g. rhEPO injection was provided by Sansheng pharmaceuticals company, Shenyang City, Liaoning Province, China, and the License number was HMLN S20010001. METHODS： A total of 75 female rats were randomly divided into rhEPO treatment, control, and sham operation groups, with 25 rats in each group. Rat models of facial nerve injury were established in the rhEPO treatment group and the control group by crushing the main trunk of the left facial nerve. Surgical microscopic observation of the facial nerve damage displayed perineurial disruption. The left stylomastoid foramen of the sham operation group were only exposed, but without nerve injury. The rhEPO treatment group was treated with rhEPO （5 000 U/kg, i.p.） once following injury and once a day for two weeks. The control and sham operation groups were treated with the same dose of normal saline （i.p.）, once following injury and once a day for two weeks. MAIN OUTCOME MEASURES： Rats were sacrificed 3, 7, 14, 21, and 28 days after injury, FMN survival after facial nerve injury was analyzed by Toluidine blue staining, and then survival ratios （L/R） were calculated. The number of apoptotic profiles in the injured FMNs were evaluated by TUNEL staining. Expression of Caspase-3 in the facial nucleus was detected by immunohistochemistry methods. RESULTS： A total of 75 rats were included in the final analysi     

Urolithin A alleviates blood-brain barrier disruption and attenuates neuronal apoptosis following traumatic brain injury in mice

Urolithin A(UA)is a natural metabolite produced from polyphenolics in foods such as pomegranates,berries,and nuts.UA is neuroprotective against Parkinson’s disease,Alzheimer’s disease,and cerebral hemorrhage.However,its effect against traumatic brain injury remains unknown.In this study,we established adult C57BL/6J mouse models of traumatic brain injury by controlled cortical impact and then intraperitoneally administered UA.We found that UA greatly reduced brain edema;increased the expression of tight junction proteins in injured cortex;increased the immunopositivity of two neuronal autophagy markers,microtubule-associated protein 1A/B light chain 3A/B(LC3)and p62;downregulated protein kinase B(Akt)and mammalian target of rapamycin(mTOR),two regulators of the phosphatidylinositol 3-kinase(PI3K)/Akt/mTOR signaling pathway;decreased the phosphorylation levels of inhibitor of NFκB(IκB)kinase alpha(IKKα)and nuclear factor kappa B(NFκB),two regulators of the neuroinflammation-related Akt/IKK/NFκB signaling pathway;reduced blood-brain barrier permeability and neuronal apoptosis in injured cortex;and improved mouse neurological function.These findings suggest that UA may be a candidate drug for the treatment of traumatic brain injury,and its neuroprotective effects may be mediated by inhibition of the PI3K/Akt/mTOR and Akt/IKK/NFκB signaling pathways,thus reducing neuroinflammation and enhancing autophagy.     

微囊化兔坐骨神经组织细胞移植对大鼠损伤脊髓核因子κB表达的影响

BACKGROUND： It has been reported that nuclear factor-kappa B （NF- κB）, activated after spinal cord injury in rats, plays a key role in inflammatory responses in the central nervous system. OBJECTIVE： To investigate the effects of transplantation of microencapsulated rabbit sciatic nerve on NF- κB expression and motor function after spinal cord injury in rats, and to compare the results with the transplantation of rabbit sciatic nerve alone. DESIGN, TIME AND SETTING： This completely randomized, controlled study was performed at the Department of Neurobiology, Medical College of Nanchang University between December 2007 and July 2008. MATERIALS： A rabbit anti-NF- κB P65 monoclonal antibody was made by the Santa Cruz Company, USA and a streptavidin peroxidase immunohistochemical kit was provided by the Sequoia Company, China. METHODS： Eight rabbits were used to prepare a sciatic nerve cell suspension that was divided into two parts： one stored for transplantation, and the other mixed with a 1.5% sodium alginate solution. One hundred and twenty adult Sprague Dawley rats weighing 220-250 g were randomly divided into four groups： the microencapsulated cell group （n = 36）, the non-encapsulated cell group （n = 36）, the saline group （n = 36） and the sham operation group （n = 12）. The first three groups underwent a right hemisection injury of the spinal cord at the T10 level, into which was transplanted a gelatin sponge soaked with 10 μL of a microencapsulated nerve tissue/cell suspension （microencapsulated cell group）, a tissue/cell suspension （non-encapsulated cell group） or physiological saline （saline group）. In the sham operation group the vertebrae were exposed, but the spinal cord was not injured, and no implantation was given. MAIN OUTCOME MEASURES： Pathological changes were detected using hematoxylin-eosin staining; NF- κB expression was quantified using immunohistochemical staining; motor function was assessed using the Basso, Beattie and Bresnahan （BBB） scale. RESULTS： Spinal cord injuries, such as neuronal death and inflammatory cell infiltration, were found in the microencapsulated cell group, the non-encapsulated cell group and the saline group. However, the damage in the microencapsulated cell group was milder than in the non-encapsulated cell or saline groups. NF- κB expression in the microencapsulated cell group, the non-encapsulated cell group and the saline group was increased after spinal cord injury; it reached a peak after 24 hours, gradually decreased after 3 days, and was close to normal levels after 7 days. NF- κB expression in the microencapsulated cell group was significantly lower than in the saline group and the non-encapsulated cell group （P 〈 0.05）. With time, the motor function of the animals in each group improved to a certain extent, but did not reach normal levels. There were no significant differences in BBB scores between the different groups on post-operative day 3; however, the BBB scores for the microencapsulated cell group and the non-encapsulated cell group were significantly higher than the saline group on post-operative day 7 （P 〈 0.05）. In addition, the motor function recovered better in the microencapsulated cell group than in the non-encapsulated cell group （P 〈 0.05）. CONCLUSION： The transplantation of microencapsulated rabbit sciatic nerve can inhibit NF- κB expression and inflammatory reactions and promote recovery of motor function after spinal cord injury in rats. The effects of microencapsulated cell transplantation are superior to those of transplantation of cells alone.     

Dexmedetomidine attenuates traumatic brain injury: action pathway and mechanisms

Traumatic brain injury induces potent inflammatory responses that can exacerbate secondary blood-brain barrier(BBB) disruption, neuronal injury, and neurological dysfunction. Dexmedetomidine is a novel α2-adrenergic receptor agonist that exert protective effects in various central nervous system diseases. The present study was designed to investigate the neuroprotective action of dexmedetomidine in a mouse traumatic brain injury model, and to explore the possible mechanisms. Adult male C57 BL/6 J mice were subjected to controlled cortical impact. After injury, animals received 3 days of consecutive dexmedetomidine therapy(25 μg/kg per day). The modified neurological severity score was used to assess neurological deficits. The rotarod test was used to evaluate accurate motor coordination and balance. Immunofluorescence was used to determine expression of ionized calcium binding adapter molecule-1, myeloperoxidase, and zonula occluden-1 at the injury site. An enzyme linked immunosorbent assay was used to measure the concentration of interleukin-1β(IL-1β), tumor necrosis factor α, and IL-6. The dry-wet weight method was used to measure brain water content. The Evans blue dye extravasation assay was used to measure BBB disruption. Western blot assay was used to measure protein expression of nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3(NLRP3), caspase-1 p20, IL-1β, nuclear factor kappa B(NF-κB) p65, occluding, and zonula occluden-1. Flow cytometry was used to measure cellular apoptosis. Results showed that dexmedetomidine treatment attenuated early neurological dysfunction and brain edema. Further, dexmedetomidine attenuated post-traumatic inflammation, up-regulated tight junction protein expression, and reduced secondary BBB damage and apoptosis. These protective effects were accompanied by down-regulation of the NF-κB and NLRP3 inflammasome pathways. These findings suggest that dexmedetomidine exhibits neuroprotective effects against acute(3 days) post-traumatic inflammatory responses, potentially via suppression of NF-κB and NLRP3 inflammasome activation.     

LncRNA Airsci increases the inflammatory response after spinal cord injury in rats through the nuclear factor kappa B signaling pathway

Spinal cord injury(SCI) is a serious traumatic event to the central nervous system. Studies show that long non-coding RNAs(lncRNAs) play an important role in regulating the inflammatory response in the acute stage of SCI. Here, we investigated a new lncRNA related to spinal cord injury and acute inflammation. We analyzed the expression profile of lncRNAs after SCI, and explored the role of lncRNA Airsci(acute inflammatory response in SCI) on recovery following acute SCI. The rats were divided into the control group, SCI group, and SCI + lncRNA Airsci-siRNA group. The expression of inflammatory factors, including nuclear factor kappa B [NF-κB(p65)], NF-κB inhibitor IκBα and phosphorylated IκBα(p-IκBα), and the p-IκBα/IκBα ratio were examined 1–28 days after SCI in rats by western blot assay. The differential lncRNA expression profile after SCI was assessed by RNA sequencing. The differentially expressed lncRNAs were analyzed by bioinformatics technology. The differentially expressed lncRNA Airsci, which is involved in NF-κB signaling and associated with the acute inflammatory response, was verified by quantitative real-time PCR. Interleukin(IL-1β), IL-6 and tumor necrosis factor(TNF-α) at 3 days after SCI were measured by western blot assay and quantitative real-time PCR. The histopathology of the spinal cord was evaluated by hematoxylin-eosin and Nissl staining. Motor function was assessed with the Basso, Beattie and Bresnahan Locomotor Rating Scale. Numerous differentially expressed lncRNAs were detected after SCI, including 151 that were upregulated and 186 that were downregulated in the SCI 3 d group compared with the control group. LncRNA Airsci was the most significantly expressed among the five lncRNAs involved in the NF-κB signaling pathway. LncRNA Airsci-siRNA reduced the inflammatory response by inhibiting the NF-κB signaling pathway, alleviated spinal cord tissue injury, and promoted the recovery of motor function in SCI rats. These findings show that numerous lncRNAs are differentially expressed following SCI, and that inhibiting lncRNA Airsci reduces the inflammatory response through the NF-κB signaling pathway, thereby promoting functional recovery. All experimental procedures and protocols were approved by the approved by the Animal Ethics Committee of Jining Medical University(approval No. JNMC-2020-DW-RM-003) on January 18, 2020.     

Edema and neuronal apoptosis in the hippocampus and cortex of elderly rats following transient cerebral ischemia/reperfusion injury

BACKGROUND： Previous studies of cerebral ischemia have used young animals, with an ischemic time greater than 5 minutes （safe time limit）. Despite an increased understanding of neuronal apoptosis, it remains uncertain whether brief cerebral ischemic events of 5 minutes or less damage brain tissue in elderly rodents. OBJECTIVE： To investigate the effects of transient cerebral ischemia （5 minutes）/reperfusion injury on brain cortical and hippocampal edema, aquaporin-4 （AQP-4） expression, and neuronal apoptosis in aged rats, and to compare ischemic sensitivity between cortex and hippocampus. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed at the Institute of Cerebrovascular Disease, Qingdao University Medical School from April 2008 to March 2009. MATERIALS： Rabbit anti-AQP-4 polyclonal antibody, TUNEL kit, and SABC immunohistochemistry kit were purchased from Wuhan Boster Bioengineering, China. METHODS： A total of 160 healthy, male, aged 19-21 months, Wistar rats were randomly assigned to 4 groups： sham-surgery, and ischemia 1-, 3-, and 5-minute groups, with 40 rats in each group. The global cerebral ischemia model was established using the Pusinelli four-vessel occlusion, and the three cerebral ischemia groups were subdivided into reperfusion 12-hour, 1-, 2-, 3-, and 7-day subgroups, with 8 rats in each subgroup. The sham-surgery group was subjected to exposure of the first cervical bilateral alar foramina and bilateral common carotid arteries. MAIN OUTCOME MEASURES： The dry-wet weight assay was used to measure brain water content and histopathology of the cortex and hippocampus was observed following hematoxylin-eosin staining. In addition, cortical and hippocampal AQP-4 expression was detected by streptavidin-biotin complex immunohistochemistry, and neuronal apoptosis was detected by the TUNEL method. RESULTS： There was no significant difference in brain water content or AQP-4 expression in the cortex and hippocampus between ischemia 1- and 3-minute groups and the sham-surgery group or brain water content or AQP-4 expression in the cortex between ischemia 5-minute group and sham-surgery group （P 〉 0.05）. However, brain water content and AQP-4 expression in the hippocampus after 5 minutes of cerebral ischemia were significantly increased compared with the sham-surgery group （P 〈 0.05 or P 〈 0.01）. Several TUNEL-positive cells were observed in the cortex and hippocampus of the sham-surgery group and ischemia 1-minute group, as well as in the cortex of the ischemia 3-minute group. In addition, the number of apoptotic neurons in the hippocampus of ischemia 3-minute group and in the cortex and hippocampus of ischemia 5-minute group was significantly increased （P 〈 0.05 or P 〈 0.01 ）. Neuronal apoptosis was increased after 12 hours of ischemia/reperfusion, and it reached a peak by 2 days （P 〈 0.01）. CONCLUSION： Transient cerebral ischemia （5 minutes） resulted in increased hippocampal edema, AQP-4 expression, and neuronal apoptosis. Moreover, cerebral ischemia had a greater effect on neuronal apoptosis than brain edema or AQP-4 expression, and the hippocampus was more sensitive than the cortex.     

Effect of Ganoderma lucidum spore on expression of insulin-like growth factor-1, nuclear factor-kappa B, and neuronal apoptosis in the epileptic rat brain

BACKGROUND: It has been reported that Ganoderma lucidum spore powder, a very well known Chinese traditional medicine, can affect immunoregulation, free radical scavenging, and anti-hypoxia responses. OBJECTIVE: To investigate the effect of Ganoderma lucidum spore powder on expression of insulin-like growth factor-1 (IGF-1), nuclear factor-κB (NF-κB) and neuronal apoptosis in rats with pentylenetetrazol (PTZ)-induced epilepsy.DESIGN, TIME AND SETTING: A cellular and molecular biology experiment with randomized controlled study design was performed at the Central Laboratory of Basic Medical College of Jiamusi University from June to August 2005.MATERIALS: Thirty healthy, adult, male, Wistar rats were selected and randomly divided into 3 groups (10rats per group): control, epilepsy model, and Ganoderma lucidum spore powder. A sub-eclampsia PTZ dose (35 mg/kg) was intraperitoneally injected to induce epilepsy in the latter two groups. Wild Ganoderma lucidum spore powder (30 g/L) was provided by the wild Ganoderma lucidum plant nursery at Jiamusi,China. lmmunohistochemical detection and terminal deoxynucleotidyl transferase-mediate dUTP nick end-labeling (TUNEL) kits were purchased from Wuhan Boster Biological Technology Co., Ltd., China.METHODS: Ganoderma lucidum spore powder was intragastrically administered at a dose of 10.0 mL/kg,once a day for 28 days. In the epilepsy and control groups, an equivalent volume of normal saline was intragastrically administered.MAIN OUTCOME MEASURES: lmmunoreactivity for IGF-1 and NF-κB/P65 were detected by immunohistochemical staining. Neuronal apoptosis was detected using TUNEL methods.RESULTS: The hippocampus and cerebral cortex of rats with PTZ-induced epilepsy exhibited a higher number of apoptotic cells at high magnification (x400), compared with the control group. Expression of IGF-1and NF-κB were higher in the epilepsy group, compared with the control group (P < 0.01). In Ganoderma lucidum spore-treated rats, fewer apoptotic cells were observed in the hippocampus and cerebral cortex,expression of NF-κB/P65 was lower, and immunoreactivity to IGF-1 increased more distinctly, compared with the epilepsy group. In addition, seizure latency was longer on 17, 21, and 25 days post-PTZ treatment in the Ganoderma lucidum spore powder group, compared with the epilepsy group (P < 0.05 0.01).CONCLUSION: Ganoderma lucidum spore powder down-regulated expression of NF-κB in brain tissues of rats with PTZ-induced epilepsy, increased immunoreactivity to IGF-1, and inhibited neuronal apoptosis.These results indicated that Ganoderma lucidum spore powder has a neuroprotective effect.     

Acupuncture for cerebral ischemia/reperfusion injury Does it reduce the inflammatory reaction?

BACKGROUND:Nuclear factor-κB (NF-κB), intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) in brain tissue can participate in inflammatory reactions after cerebral ischemia.Acupuncture treatment for acute cerebral ischemia produces abnormal protein expression.OBJECTIVE:To investigate the effects of acupuncture on NF-κB, ICAM-1, and VCAM-1 mRNA and protein expression in the brain tissue of rats with cerebral ischemia/reperfusion injury.DESIGN, TIME AND SETTING:Randomized...     

大鼠颅脑损伤后脑组织miR-122-5p含量变化及其对神经功能的影响

目的 探讨大鼠颅脑损伤后脑组织miR-122-5p含量变化及其对神经功能的影响。方法 将40只成年SD大鼠随机分为假手术组,TBI模型组,乱序miRNA组,miR-122-5p模拟物组。采用Feeney法制备TBI大鼠模型;乱序miRNA组造模24 h后,立体定向注射乱序miRNA 5 μl（20 μmol/L）;miR-122-5p模拟物组造模24 h后,立体定向注射miR-122-5p模拟物组5 μl（20 μmol/L）。qRT-PCR法检测大鼠脑组织miR-122-5p的表达变化;免疫印迹法法检测p53蛋白表达水平;水迷宫法检测学习记忆功能;TUNEL法检测脑组织细胞凋亡情况;流式细胞术检测脑细胞线粒体膜电位的变化。结果 与假手术组大鼠比较,模型组和乱序miRNA组大鼠脑组织miR-122-5p表达明显减少,p53蛋白显著上调,脑组织细胞凋亡数明显增多,线粒体膜电位下降显著,水迷宫测试大鼠寻找隐形平台时间显著延长;与模型组大鼠比较,miR-122-5p模拟物组大鼠miR-122-5p表达明显增加,并伴随p53蛋白低表达,细胞凋亡水平下降,神经功能障碍得到明显逆转。结论 颅脑损伤后miR-122-5p的表达下调可能导致p53蛋白的表达升高,促进神经细胞凋亡。     

IL-8单抗对颅脑损伤后继发性脑损害的保护作用

目的　观察抗IL 8单抗对兔脑损伤后脑内炎症反应的抑制作用 ,以及对血脑屏障通透性和创伤性脑水肿的影响 ,探讨颅脑损伤后继发性脑损害新的治疗方法。方法　采用自由落体兔脑损伤模型 ,观察家兔抗IL 8单抗治疗前后脑组织中IL 8表达、中性粒细胞 (PMNL)浸润有无变化 ,同时检测脑组织含水量的变化 ,并用胶体金示踪 ,电镜观察抗IL 8单抗使用前后血脑屏障通透性有无改善。结果　抗IL 8单抗治疗组与对照组相比 ,伤后脑组织中IL 8无表达 ,PMNL浸润也明显减少 (P <0 .0 1 ) ,血脑屏障通透性降低 ,脑含水量下降 (P <0 .0 5)。结论　颅脑损伤后早期给予抗IL 8单抗治疗 ,可抑制IL 8的表达 ,抑制IL 8趋化PMNL的作用 ,减少组织中PMNL的浸润 ,减轻脑损伤后脑内炎症反应 ,降低血脑屏障通透性 ,减轻创伤性脑水肿 ,从而改善继发性脑损害。     

Effect of systemic LPS injection on cortical NF-kappaB activity and inflammatory response following traumatic brain injury in rats

The aim of current study is to investigate the effect of systemic administration of lipopolysaccharide (LPS) on the temporal pattern of cortical nuclear factor kappa B (NF-kappaB) binding activity, inflammatory response and secondary damage in the injured brain following traumatic brain injury (TBI). Right parietal cortical contusion in rats was made by using weight-dropping method. The rats were randomly divided into sham, LPS, TBI and TBI-LPS groups, with LPS injected intraperitoneally. NF-kappaB binding activity, cytokines, intercellular adhesion molecule-1 (ICAM-1) and brain damage were detected by electrophoretic mobility shift assay (EMSA), enzyme-linked immunosorbent assay (ELISA), immunohistochemistry and terminal deoxynucleotidyl-transferase-mediated biotin-dUTP nick end labeling (TUNEL) apoptosis, respectively. The results showed that systemic administration of LPS following TBI could induce an immediate, strong and persistent upregulation of NF-kappaB, tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6) and ICAM-1 in the area surrounding the injured brain. As compared with rats of sham, LPS and TBI groups, NF-kappaB binding activity, TNF-alpha and IL-6 were significantly upregulated in the surrounding cortex of injured site as early as 3 h postinjury when challenged with LPS, kept at high level up to 7-days postinjury. ICAM-1-positive vessels and apoptotic TUNEL-positive cells in the injured brain were also significantly increased in TBI-LPS rats. It was concluded that inflammatory response and secondary brain damage occurred in the injured brain could be highly exacerbated by endotoxemia.     

阿托伐他汀对颅脑损伤大鼠神经元凋亡的抑制作用

目的 探讨阿托伐他汀对颅脑损伤（TBI）大鼠神经元凋亡的抑制作用及机制。方法 30只SD大鼠随机分为假手术组、模型组和阿托伐汀他组，各10只。采用液压打击法制作TBI模型，阿托伐他汀组连续灌胃阿托伐他汀2周（1 mg/kg/d），假手术组、模型组灌胃等体积生理盐水。给药结束后第2天，参照Zea Longa 5分制标准进行神经功能评分。酶联免疫吸附法检测血清肿瘤坏死因子（TNF-α）、白介素（IL）-6和IL-1β水平；免疫印迹法检测损伤脑组织Toll样受体4（TLR4）、核转录因子（NF）-κB p65、p-IκB、cleaved Caspase-3蛋白表达；末端标记法检测神经元凋亡；HE染色观察脑组织病理变化。结果 与模型组相比，阿托伐他汀组大鼠神经功能缺损评分、细胞凋亡率、血清IL-6、TNF-α和IL-1β水平明显改善（P<0.05），损伤脑组织TLR4、NF-KB p65、p-IκB、cleaved Caspase-3水平明显下调（P<0.05）；HE染色显示脑组织损伤程度明显减轻。结论 阿托伐他汀可能通过抑制TLR4/NF-кB信号通路，抑制TBI大鼠的神经元细胞凋亡，促进神经功能恢复。     

七叶皂苷钠对大鼠脑缺血再灌注损伤的保护作用

目的 探讨七叶皂苷钠对大鼠脑缺血再灌注损伤的作用及机制。方法 60只成年SD大鼠随机分为假手术组、模型组和七叶皂苷钠组,各20只。采用线栓法建立大鼠局灶性大脑中动脉闭塞再灌注损伤模型,七叶皂苷钠组建模成功后1 h腹腔注射七叶皂苷钠（2.8 mg/kg）,假手术组和模型组腹腔注射等量生理盐水。造模后24 h,使用Longa评分评估大鼠神经功能损伤程度,使用称重法检测大鼠脑水肿程度,使用ELISA法测定大鼠损伤脑组织超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、丙二醛（MDA）、肿瘤坏死因子（TNF-α）、白细胞介素6（IL-6）及白细胞介素1β（IL-1β）的含量,使用TUNEL法检测损伤脑组织神经元凋亡率,使用蛋白免疫印迹法检测损伤脑组织双特异性磷酸酶1（DUSP1）、核转录因子-κB（NF-κB）p65、Bcl-2及Bax蛋白的表达。结果 与假手术组比较,模型组大鼠Longa评分显著增加（P<0.01）,脑含水量显著升高（P<0.01）,损伤脑组织MDA、TNF-α、IL-1β和IL-6水平显著增高（P<0.001）,损伤脑组织SOD和CAT水平显著降低（P<0.001）,损伤脑组织神经元凋亡率显著升高（P<0.01）,损伤脑组织DUSP1和Bcl-2蛋白表达水平显著降低（P<0.05）,损伤脑组织NF-kB p65和Bax蛋白表达水平显著增高（P<0.05）。七叶皂苷钠显著逆转大鼠上述反应（P<0.05）。结论 七叶皂苷钠显著改善大鼠脑缺血再灌注损伤,机制可能与减轻炎症反应、氧化应激反应、神经元凋亡等有关。     

创伤性颅脑损伤后脑组织中TLR4表达的实验研究

目的 研究创伤性脑损伤(TBI)后损伤灶周围脑组织Toll样受体4(TLR4)的表达,探讨TLR4/NF-κB信号通路在TBI中的作用机制.方法 SD大鼠36只按随机数字表法分为对照组(n=12)、TBI后1d组(n=6)、TBI后3d组(n=12)和TBI后7d组(n=6),后3组采用Feeney自由落体撞击法制作TBI模型,对照组仅行右侧顶部开窗而无TBI.应用RT-PCR、凝胶电泳迁移率实验(EMSA)、ELISA分别检测4组大鼠挫伤脑组织TLR4 mRNA、NF-κB活性、TNF-α和IL-6浓度的变化;免疫组化染色检测对照组和TBI后3d组大鼠挫伤脑组织TLR4的表达.结果 与对照组比较,TBI后1d、3d、7d组TLR4 mRNA表达、NF-κB活性、TNF-α和IL-6浓度均增加,差异有统计学意义(P＜0.05);对照组脑组织TLR4表达较少,TBI后3d组创伤灶周围可见大量TLR4阳性细胞,主要表达在皮层胶质细胞、神经元中;NF-κB活性与TLR4 mRNA的表达呈正相关关系(r=0.786,P=-0.000).TNF-α、IL-6与TLR4的表达也呈正相关关系(r=0.517,P=0.010;r=0.503,P=0.012).结论 TBI可引起损伤区脑组织TLR4的表达和下游NF-κB、促炎症因子水平的增加,TLR4/NF-κB信号通路可能在脑组织的继发性损害中起重要作用.     

重组人促红细胞生成素对大鼠局灶性脑缺血再灌注损伤所致NF - κB和IκB表达的影响

目的 探讨NF - κB和IκB在重组人促红细胞生成素(r- HuEPO)对大鼠局灶性脑缺血再灌注炎性反应损伤的保护机制中的作用.方法 采用栓线法制备大鼠局灶性脑缺血再灌注模型(MCAO),应用免疫组化和Western blot分别检测缺血脑组织NF - κB和IκB的表达,IL-1β蛋白含量采用ELISA法确定.结果 与假手术组相比,脑缺血2h再灌注3h后缺血侧皮质IL- 1β含量显著升高至(86.2±25.2)pg/ml(P＜0.05),再灌注24 h IL- 1β含量达高峰(867.2±74.3)pg/ml(P＜0.01),72 h仍处于较高水平(185.5±24.4)pg/ml(P＜0.01).EPO治疗组缺血再灌注3h、6h、12 h(164.1±11.6)pg/ml和24h缺血侧皮质IL- 1β含量显著降低,与病理组相应时间点相比,分别降低了55％、33％、56％和50％(P＜0.01).脑缺血再灌注组各时相点NF - κB p65表达及活化明显增加,为Sham组的4～8倍(P＜0.01),12h表达最高(P＜0.01),是Sham组的13倍.EPO治疗组与病理组相应时相点相比,NF - κB p65表达显著减弱,EPO处理后1、3、6和12 h,NF - κB p65表达较相应的I/R组降低了33％ ～40％(P＜0.01).缺血2h再灌注1h后缺血侧皮质IκBα蛋白水平从248.6±4.2降低至195.3±4.8(P ＜0.01),6h降至最低(134.7±19.9,P＜0.01).EPO治疗组可显著增高缺血再灌注组缺血侧皮质IκBa蛋白水平(P＜0.01),各时相点分别增高了11％、34％、83％、40％、23％和20％.结论 EPO可能通过抑制NF - κB/IκB信号传导通路,减少炎性因子IL-1β的合成和分泌而达到保护脑损伤的作用.     

葛根素通过Nrf2-ARE信号通路抵抗氧化应激对创伤性脑损伤的神经保护作用

目的 探讨葛根素对创伤性脑损伤(TBI)模型大鼠的神经保护作用及脑组织红系衍生的核因子相关因子2(Nrf2)一抗氧化反应原件(ARE)信号通路参与的机制。方法 选择健康成年雄性大鼠体重250～300 g构建TBI模型,将大鼠分为4组:创伤组(A组)、假手术组(B组)、葛根素治疗的创伤组(C组)和葛根素治疗的假手术组(D组); 通过采用改良的神经功能缺损评分(mNSS)评价神经功能,脑组织干湿重称量法评价脑水肿,Nissl染色,TUNEL染色评价脑损伤体积和神经元的凋亡,使用酶活试剂盒检测损伤48 h后抗氧化酶SOD,GSH,和GSSG的活性以及氧化应激产物MDA和NO的水平,最后使用western blot和RT-PCR的方法检测Nrf2-ARE信号通路及其下游分子HO-1,NQO1的表达水平。结果 TBI手术后损伤组mNSS评分明显增高(P<0.05),葛根素治疗组能够明显降低mNSS评分(P<0.05)。TBI手术后损伤组脑水肿加重及神经元凋亡增加(P<0.05),葛根素治疗组能够明显挽救脑水肿及神经元凋亡(P<0.05)。TBI手术12 h后损伤组脑内抗氧化酶SOD,GSH,和GSSG的活性增加及氧化应激产物MDA和NO的水平升高(P<0.05),葛根素治疗组能够明显降低抗氧化酶SOD,GSH,和GSSG的活性以及氧化应激产物MDA和NO的水平(P<0.05)。western blot和RT-PCR显示葛根素不改变Nrf2的翻译和表达,但是RT-PCR显示葛根素能够明显促进Nrf2-ARE信号通路下游分子HO-1,NQO1的表达。结论 葛根素可能通过Nrf2-ARE信号通路抵抗氧化应激对创伤性脑损伤发挥神经保护作用。     

西维来司钠对小鼠颅脑创伤后神经保护作用的研究

目的 探讨中性粒细胞弹性蛋白酶(NE)特异性抑制剂两维来司钠(ONO-5046)在小鼠创伤性颅脑损伤(TBI)后的抗凋亡作用.方法 64只C57BL/6小鼠随机分为对照组、TBI组、TBI+ONO-5046低剂量组(30 mg/kg)以及TBI+ ONO-5046高剂量组(50 mg/kg),所有小鼠均于致伤后24h处死,分别应用实时聚合酶链式反应(PCR)、Westem blot检测挫伤灶周围皮层caspase3、bcl-2、bcl-xl的表达水平.采用末端脱氧核苷酸转移酶介导的生物素脱氧尿嘧啶核苷酸缺口末端标记法( TUNEL)检测皮层神经元凋亡.结果 TBI后损伤灶周围皮层caspase3的mRNA及蛋白表达水平明显升高;bcl-2、bc1-xl的mRNA表达水平有轻度升高;TUNEL阳性细胞显著增多.施加ONO-5046治疗后,caspase3 mRNA及蛋白表达水平明显降低;bcl-2、bcl-xl的mRNA及蛋白表达水平显著升高;TUNEL阳性细胞显著减少,其中50 mg/kg剂量组阳性细胞数减少更为明显(P＜0.05).结论 ONO-5046能够明显抑制TBI后脑组织中caspase3的表达,并且促进bcl-2、bcl-xl的表达,有效抑制神经细胞的凋亡,减轻TBI后的继发性脑损害.