The role of tumor necrosis factor receptor superfamily members in mammalian brain development, function and homeostasis

Tumor necrosis factor receptor superfamily (TNFRSF) members were initially identified as immunological mediators, and are still commonly perceived as immunological molecules. However, our understanding of the diversity of TNFRSF members' roles in mammalian physiology has grown significantly since the first discovery of TNFRp55 (TNFRSF1) in 1975. In particular, the last decade has provided evidence for important roles in brain development, function and the emergent field of neuronal homeostasis. Recent evidence suggests that TNFRSF members are expressed in an overlapping regulated pattern during neuronal development, participating in the regulation of neuronal expansion, growth, differentiation and regional pattern development. This review examines evidence for non-immunological roles of TNFRSF members in brain development, function and maintenance under normal physiological conditions. In addition, several aspects of brain function during inflammation will also be described, when illuminating and relevant to the non-immunological role of TNFRSF members. Finally, key questions in the field will be outlined.     

Neuron death and glial response in pontosubicular necrosis. The role of the growth inhibition factor

AIM AND METHODS: Fluorochrome and immunohistochemical studies were performed on neonates with pontosubicular necrosis (PSN), aged 26 - 42 weeks of gestation (GW), compared with preterm and term controls aged from 10 GW to 3 months of age. RESULTS: A fluorochrome study using a confocal microscope revealed that nuclear DNA changes occurred earlier than cytoplasm degeneration with diminished RNA orange-red fluorescence. These changes were restricted to the small immature neurons in the pons and subiculum with PSN. On the other hand, although glial fibrillary acidic protein-positive reactive astrocytes were not increased in number, growth inhibitory factor- (GIF) immunoreactive glia with vesicular large nuclei were increased in number within the gray matter of the pons, subiculum, and cerebral cortex in the PSN group. The nuclei of GIF-containing astrocytes became round and vesicular, nearly twice in size and increased in number. Thus, the neuronal death began at the nuclei of selective neurons in specific areas in PSN, although GIFcontaining astrocytes were increased in widespread areas. CONCLUSION: These facts suggest that immature neurons in the pontine nuclei and subiculum are selectively vulnerable to some insults such as hypocarbia and hyperoxygenation, and PSN involves a possible apoptotic neuron death mechanism and a characteristic glial response.     

Changes in tumor necrosis factor alpha and myeloper-oxidase in mouse models of local cerebral infarction induced by photochemical method

BACKGROUND: Lots of evidences have demonstrated that acute inflammatory reaction plays an important role in cerebral ischemia and cerebral ischemia/reperfusion injury. Tumor necrosis factor (TNF), as one of important inflammatory cytokines, also participates in the injury. OBJECTIVE: To observe the changes in TNF-α expression and myeloperoxidase (MPO) activity of mouse models of local cerebral infarction induced by photochemical method, and analyze the correlation of TNF-α expression and MPO activity. DESIGN: Randomized controlled experiment. SETTING: Laboratory of Cerebral Microcirculation, Taishan Medical College. MATERIALS: Sixty involved male adult Kunming mice were provided by the Experimental Animal Center of Shandong University. TNF-α primary antibody, kits for enzyme-linked immunosorbent assay(ELISA) and streptavidin-biotin complex immunohistochemical dyeing kit were purchased from Boster Company(Wuhan). MPO kit was purchased from Jiancheng Bioengineering Institute (Nanjing). Cold light source was developed by Hengfa Co.,Ltd.( LG-150, Xuzhou). METHODS: This experiment was carried out in the Laboratory of Cerebral Microcirculation of Taishan Medical College between July 2004 and July 2005. The involved 60 Kunming mice were randomized into 3 groups: normal control group (n =6), sham-operation group (n =6) and model group (n =48). Mice in the model group were observed at 30 minutes, 1, 3, 6, 12, 24, 48 and 72 hours after illumination, separately, 6 mice at each time point. In the model group, mice models of local cerebral infarction were developed as follows: The mice were anesthetized to expose left skulls. Taking 2 mm left to sagittal suture and 2 mm posterior to coronal suture as center, a field with diameter of 3 mm for illumination was set. The optical fiber detecting head of cold light source was vertically close to exposed skull. The mice were injected with rose Bengal for 5 minutes, and then cold light source was open for 10 minutes. Illumination was omitted in the sham-operation group. Mice in the control group were not modeled. At postoperative 6 hours, TNF-α expression in infracted-side cortex was detected with immunohistochemical method and ELISA, and MPO activity in infracted-side cortex with chromatometry. MPO activity could reflect the infiltration degree of neutrophils in tissue. Stronger activity indicated severer infiltration. Single-factor analysis of variance was used for comparison among groups, q test for pairwise comparison and correlative analysis for detecting the inter-parameter correlation. MAIN OUTCOME MEASURES: Changes in TNF-α expression and MPO activity of left cortex of mice in each group. RESULTS: Sixty mice were involved in the final analysis. After cerebral infarction, TNF-α positive cells were neurons and glial cells mainly, distributing in and around the infarct region. TNF-α expression in cortex of mice of sham-operation group was （615.7±16.1） ng/L, and that of model group increased to （792.2±17.8） ng/L at 3 hours after illumination, and reached peak [（921.9±23.9） ng/L] at 6 hours after illumination, and decreased to （848.0±30.6） ng/L at 12 hours after illumination and recovered to the normal level [（625.3±14.3） ng/L] at 72 hours after illumination. MPO activity of sham-operation group was （7.151±0.433） nkat/g, and that of model group increased to （10.469±0.600） nkat/g at 3 hours after illumination, reached the peak [（15.486±0.650） nkat/g] at 12 hours after illumination, decreased to （11.052±0.617） nkat/g at 24 hours after illumination and recovered to the normal level [（7.418±0.617） nkat/g] at 72 hours after illumination. Change of MPO activity lagged behind that of TNF-α, and correlative analysis showed that the both were positively correlated（r =0.953, P < 0.01）. CONCLUSION: In the acute stage of cerebral infarction of mice induced by photochemical method, TNF-α expression in infarcted-side cortex is closely related with infiltration of neutrophils. TNF-α induces inflammatory cells to intrude into ischemic brain tissue, and participates in the inflammatory reaction process at the early stage of cerebral ischemia.     

The role of tumour necrosis factor alpha and soluble tumour necrosis factor alpha receptors in the symptomatology of schizophrenia

Background Immunological mechanisms may be responsible for the development and maintenance of schizophrenia symptoms. Aim The aim of this study is to measure tumour necrosis factor-alpha (TNF-α), soluble tumour necrosis factor-alpha receptor I (sTNF-αRI), and soluble tumour necrosis factor-alpha receptor II (sTNF-αRII) levels in patients with schizophrenia and healthy individuals, and to determine their relationship with the symptoms of schizophrenia. Methods Serum TNF-α, sTNF-αRI and sTNF-αRII levels were measured. The Positive and Negative Syndrome Scale (PANSS) was administered for patients with schizophrenia (n?=?35), and the results were compared with healthy controls (n?=?30). Hierarchical regression analyses were undertaken to predict the levels of TNF-α, sTNF-αRI and sTNF-αRII. Results No significant difference was observed in TNF-α levels, but sTNF-αRI and sTNF-αRII levels were lower in patients with schizophrenia. Serum sTNF-αRI and sTNF-αRII levels were found to be negatively correlated with the negative subscale score of the PANSS, and sTNF-αRI levels were also negatively correlated with the total score of the PANSS. Smoking, gender, body mass index were not correlated with TNF-α and sTNF-α receptor levels. Conclusions These results suggest that there may be a change in anti-inflammatory response in patients with schizophrenia due to sTNF-αRI and sTNF-αRII levels. The study also supports low levels of TNF activity in schizophrenia patients with negative symptoms.     

早期生长反应基因1对巨噬细胞分泌肿瘤坏死因子α的影响

背景：体内外研究已证实肺巨噬细胞合成和分泌肿瘤坏死因子α等参与肺组织局部损伤和炎症反应，但具体发生机制仍不明确。 目的：观察核转录因子早期生长反应基因1对巨噬细胞分泌肿瘤坏死因子α的影响。 设计、时间及地点：随机分组设计，于2004-06/2006-12在湘雅医学院病理学系完成。 材料：标准石英粉尘(SiO2)为Sigma公司产品；早期生长反应基因1抗体为Santa Cruz公司产品；小鼠巨噬细胞系RAW264.7购自中科院上海生物细胞研究所细胞库。 方法：实验将巨噬细胞分为正常对照组、二氧化硅刺激组、Egr-1+二氧化硅组和IgG+二氧化硅组，前两组加无血清培养基，后两组分别加入5，10，20 mg/L不同浓度的Egr-1和IgG抗体干预。 主要观察指标：酶联免疫吸附实验检测各组细胞上清中肿瘤坏死因子α蛋白的水平；反转录-聚合酶链反应检测细胞内肿瘤坏死因子α mRNA的表达。 结果：①与二氧化硅刺激组相比，不同浓度Egr-1+二氧化硅组细胞上清中肿瘤坏死因子α蛋白水平均下降(P < 0.01)，且10 mg/L 组与5，20 mg/L组相比，差异有显著性意义(P < 0.05)。不同浓度IgG+二氧化硅组相比，上清液中肿瘤坏死因子α蛋白水平差异无显著性意义(F=1.008，P=0.438)。②二氧化硅刺激组肿瘤坏死因子α mRNA表达高于正常对照组(P < 0.01)，而Egr-1+二氧化硅组mRNA表达低于二氧化硅刺激组和IgG+二氧化硅组(P < 0.01)。 结论：二氧化硅致巨噬细胞分泌肿瘤坏死因子α增加可能通过激活核转录因子早期生长反应基因1介导的信号通路而实现。     

The role of interleukin-1 and tumor necrosis factor alpha in the neurochemical and neuroendocrine responses to endotoxin.

Both interleukin-1 (IL-1) and endotoxin (lipopolysaccharide, LPS) are potent activators of the hypothalamo-pituitary-adrenal (HPA) axis, and they also increase cerebral norepinephrine metabolism and tryptophan. Injections of cause macrophages to synthesize and release various cytokines, including IL-1 and tumor necrosis factor alpha (TNF alpha). The hypothesis that macrophage production of IL-1 mediates the HPA-activating effect of LPS was tested in mice using the IL-1-receptor antagonist protein (IRAP). Administration of IRAP largely prevented the effects of IL-1 alpha or IL-1 beta on the elevation of plasma corticosterone and the concomitant increase in hypothalamic norepinephrine metabolism, but failed to alter the responses to LPS. IRAP did not prevent the increases in brain tryptophan that occurred after treatment with IL-1 or LPS. Recombinant human TNF alpha, TNF beta, IL-6, and interferon-alpha injected intraperitoneally failed to activate the HPA axis, but mouse TNF alpha was effective by this route, and human TNF alpha, TNF beta, and IL-6 were effective intravenously. None of these cytokines was as potent as IL-1. Pretreatment with an antibody specific for mouse TNF alpha, either alone or in combination with IRAP, also failed to prevent the elevation of plasma corticosterone by LPS. Thus, either IL-1 and TNF alpha are not involved in the HPA and noradrenergic responses to LPS, or there are alternative (redundant) pathways by which LPS can activate the HPA axis.     

A role for tumor necrosis factor alpha in death of dopaminergic neurons following neural transplantation

Poor survival of transplanted dopaminergic (DA) neurons remains a serious obstacle to the success of cell replacement therapy as an alternative to the current treatments for Parkinson's disease (PD). We have examined the temporal release profile of an inflammatory cytokine, tumor necrosis factor-alpha (TNFalpha), following transplantation of fetal mesencephalic tissue into the rat striatum. The amounts of TNFalpha released in vivo when added to cultures of embryonic DA neurons, significantly reduced the survival of DA neurons in vitro, and this cell death could be prevented by the inclusion of an antibody to the TNFalpha receptor type 1. Inclusion of this antibody in cell suspensions during transplantation also increased the survival of transplanted fetal DA neurons by approximately 250%. Use of this therapeutic antibody approach may offer significant improvements to neural transplantation as a treatment for PD.     

Blood interleukin-6 and tumor necrosis factor-alpha elevation after intracerebroventricular injection of Escherichia coli endotoxin in the rat is determined by two opposing factors: peripheral induction by LPS transferred from brain to blood and inhibition of peripheral response by a brain-mediated mechanism

Following intracerebroventricular injection of LPS in rats, IL-6 and TNF-alpha appear in peripheral blood. To determine whether these changes are mediated by passage of the injected LPS from the brain to the blood, the time course of appearance in blood of bioactive LPS after intracerebroventricular injection was compared with the time course of appearance of IL-6 and of TNF-alpha in blood. Bioactive LPS was detected 30 min after intracerebroventricular injection, the first time interval tested. TNF-alpha appeared in peripheral blood at 30 min, IL-6 at 60 min and both cytokines as well as LPS achieved highest levels at 120 min. To determine pharmacokinetics of LPS transfer from brain to blood more precisely, radioiodinated LPS was injected intracerebroventricularly. (125)I-LPS was detected in blood as early as 5 min after intracerebroventricular injection, reached peak levels at about 2 h, and was transferred from brain to blood at a rate corresponding to bulk flow (% of brain content per min was 1.40 +/- 0.58 and 1.00 +/- 0.21% in series 1 and 2, respectively). 70.0% of total injected LPS had entered blood by 4 h. However, when administered intravenously (by a programmed pump) at the same rate that it enters the blood after intracerebroventricular injection LPS induced a much greater cytokine response than when given intracerebroventricularly. This paradoxical response was shown in further studies to be due to the simultaneous central inhibitory effect of LPS; coinjection of intracerebroventricular LPS markedly reduced the peripheral cytokine response to intravenous LPS infusion.     

Differential role of tumor necrosis factor receptors in mouse brain inflammatory responses in cryolesion brain injury

Tumor necrosis factor-alpha (TNF-alpha) is one of the mediators dramatically increased after traumatic brain injury that leads to the activation, proliferation, and hypertrophy of mononuclear, phagocytic cells and gliosis. Eventually, TNF-alpha can induce both apoptosis and necrosis via intracellular signaling. This cytokine exerts its functions via interaction with two receptors: type-1 receptor (TNFR1) and type-2 receptor (TNFR2). In this work, the inflammatory response after a freeze injury (cryolesion) in the cortex was studied in wild-type (WT) animals and in mice lacking TNFR1 (TNFR1 KO) or TNFR2 (TNFR2 KO). Lack of TNFR1, but not of TNFR2, significantly decreased the inflammatory response and tissue damage elicited by the cryolesion at both 3 and 7 days postlesion, with decreased gliosis, lower IL-1beta immunostaining, and a reduction of apoptosis markers. Cryolesion produced a clear induction of the proinflammatory cytokines interleukin (IL)-1alpha, IL-1beta, IL-6, and TNF-alpha; this induction was significantly lower in the TNFR1 KO mice. Host response genes (ICAM-1, A20, EB22/5, and GFAP) were also induced by the cryolesion, but to a lesser extent in TNFR1 KO mice. Lack of TNFR1 signaling also affected the expression of apoptosis/cell death-related genes (Fas, Rip, p53), matrix metalloproteinases (MMP3, MMP9, MMP12), and their inhibitors (TIMP1), suggesting a role of TNFR1 in extracellular matrix remodeling after injury. However, GDNF, NGF, and BDNF expression were not affected by TNFR1 deficiency. Overall, these results suggest that TNFR1 is involved in the early establishment of the inflammatory response and that its deficiency causes a decreased inflammatory response and tissue damage following brain injury.     

The role of nitric oxide synthases in the sleep responses to tumor necrosis factor-alpha

It is well established that cytokines such as tumor necrosis factor-alpha (TNFalpha) and interleukin-1beta (IL-1beta) are involved in physiological sleep regulation, yet their downstream somnogenic mechanisms remain largely uninvestigated. Nitric oxide (NO) is an effector molecule for some TNFalpha actions. Neuronal nitric oxide synthase (nNOS) and inducible nitric oxide synthase (iNOS) gene knockout (KO) mice sleep differently than their respective controls. In this study, we tested the hypothesis that NO mediates TNFalpha-induced sleep using iNOS and nNOS KO mice and their corresponding wild-type controls. Systemic administration of TNFalpha increased non-rapid eye movement sleep (NREMS) in the two control strains and in the iNOS KO mice during the first 4 h post-injection but failed to increase NREMS in nNOS KO mice. Rapid eye movement sleep (REMS) was suppressed by TNFalpha in nNOS controls but not in the other strains examined. The results suggest that TNFalpha affects sleep, in part, through nNOS.     

The inhibitory effect of tumor necrosis factor and interleukin-1 on Ia induction by interferon-gamma on endothelial cells from murine central nervous system microvessels

The effect of both tumor necrosis factor-alpha (TNF) and interleukin-1 (IL-1) on interferon-gamma (IFN)-induced Ia expression was studied using cultured endothelial cells (EC) isolated from cerebral microvessels of SJL mice. TNF inhibited Ia induction by IFN in a dose-dependent manner. The degree of inhibition by TNF was related to the IFN concentration: 200 U/ml TNF inhibited Ia expression induced by 20 U/ml IFN by 80% and Ia induced by 100 U/ml IFN by 45%. FACS analysis revealed the induction of Ia antigen on 30-40% of EC after 3 days' culture with IFN; TNF significantly reduced the percent of EC expressing Ia antigens. Identical treatment of SJL astrocytes showed TNF augmented Ia expression induced by IFN. IL-1 also inhibited Ia induction by IFN in a manner similar to that observed with TNF. The percent reduction of Ia-positive EC by Il-1 (2.0 U/ml) was 30% and 50% during incubations with 100 and 20 U/ml IFN, respectively. When combined at suboptimal concentrations IL-1 and TNF synergistically inhibited Ia expression induced by IFN. These results demonstrate that TNF acts on EC and astrocytes in a disparate manner and indicate that TNF and IL-1 can synergistically down-regulate immune responses involving central nervous system EC.     

Postnatal development of the brain mass in guinea pigs (Cavia cobaya)

The quantitative development of body mass (BoM) and brain mass (BrM) has been studied in guinea pigs during postnatal life from the 1st day until adulthood. The increase of both the parameters (BoM, BrM) was statistically significant from the 7th day on (p less than or equal to 0.05). The growth curves of BoM and BrM can be described mathematically by non linear regression functions of which the correlation coefficients were r = 0.96 and r = 0.82, respectively. The two growth rates of BoM and BrM show negative allometry, the rate of increase of BoM being 2.45 and that of BrM 1.16 between the 1st day and day 19-25. The correlation coefficient of the BoM/BrM ratio was r = 0.87. During the postnatal brain development of the guinea pig no particular growth spurt could be observed, as it is known from other species, e.g. the rat. This finding seems to be coherent with the advanced state of the newborn guinea pig with his functioning sensory mechanisms and an important motor activity.     

The role of interleukin-1 and tumor necrosis factor α in the neurochemical and neuroendocrine responses to endotoxin

Both interleukin-1 (IL-1) and endotoxin (lipopolysaccharide, LPS) are potent activators of the hypothalamo-pituitary-adrenal (HPA) axis, and they also increase cerebral norepinephrine metabolism and tryptophan. Injections of cause macrophages to synthesize and release various cytokines, including IL-1 and tumor necrosis factor α (TNFα). The hypothesis that macrophage production of IL-1 mediates the HPA-activating effect of LPS was tested in mice using the IL-1-receptor antagonist protein (IRAP). Administration of IRAP largely prevented the effects of IL-1α or IL- 1β on the elevation of plasma corticosterone and the concomitant increase in hypothalamic norepinephrine metabolism, but failed to alter the responses to LPS. IRAP did not prevent the increases in brain tryptophan that occurred after treatment with IL-1 or LPS. Recombinant human TNFa, TNFβ, IL-6, and interferon-a injected intraperitoneally failed to activate the HPA axis, but mouse TNFa was effective by this route, and human TNFα, TNFβ, and IL-6 were effective intravenously. None of these cytokines was as potent as IL-1. Pretreatment with an antibody specific for mouse TNFα, either alone or in combination with IRAP, also failed to prevent the elevation of plasma corticosterone by LPS. Thus, either IL-1 and TNFα are not involved in the HPA and noradrenergic responses to LPS, or there are alternative (redundant) pathways by which LPS can activate the HPA axis.     

The role of the subependymal plate in avian sarcoma virus brain tumor induction:

Summary F-344 rats were inoculated intracerebrally at 1 and at 133 days of age with the Bratislava-77 strain of avian sarcoma virus. Groups of rats were sequentially sacrificed following inoculation so that early stages of microtumor formation could be evaluated. In neonatally inoculated rats incipient tumors developed in the subependymal region of the lateral ventricles in close juxtaposition to clusters of poorly differentiated germinal cells. Among these animals microtumors were detected as soon as 2 weeks after inoculation; by 4 weeks post-inoculation all rats inoculated at 1 day of age had tumors. In contrast among rats inoculated as adults incipient tumors developed in the cerebral cortex away from the subependymal region but adjacent to the locus of inoculation. Incipient tumors were uncommon in rats inoculated as adults during the first 2 months after inoculation.Supported by USPHS Grants CA-14651 and CA-11898. Dr. Copeland is supported by a National Research Service Award, CA-05431 from NCI. Dr. Bigner is the recipient of TIA fellowship 1F11NS11063 from NINCDS and a JFCF award from the American Cancer Society     

An essential role for tumor necrosis factor in the formation of experimental murine Staphylococcus aureus-induced brain abscess and clearance

Tumor necrosis factor-alpha (TNF-alpha) is a central mediator of the immune response to pathogens, but may also exert neurotoxic effects, thereby contributing to immunopathology. To define the role of TNF during the course of brain abscess, TNF-deficient (TNF(0/0) mice were stereotaxically infected with Staphylococcus (S.) aureus-laden agarose beads. In comparison to 100% survival of wild type (WT) mice, TNF(0/0) mice displayed high mortality rates (54%) in the initial phase of abscess development as well as significantly increased morbidity in the course of the disease. The worse clinical outcome was due to an increased intracerebral (i.c.) bacterial load in TNF(0/0) mice as compared to WT mice. The impaired control of S. aureus was associated with reduced inductible nitric oxide synthase (iNOS) mRNA and protein expression in TNF(0/0)mice. Similarly, numbers of inflammatory leukocytes, cytokine expression of IL-6, IL-12p40, IFNgamma IL-beta mRNA, and brain edema were significantly increased in TNF(0/0)mice as compared to WT animals. In addition, resolution of i.c. infiltrates was delayed in TNF(0/0)mice correlating with reduced apoptosis of inflammatory leukocytes and formation of a fibrous abscess capsule. Collectively, these data demonstrate that TNF is of key importance for the control of S. aureus-induced brain abscess and regulates the ensuing host immune response.     

Unilateral cortical application of tumor necrosis factor alpha induces asymmetry in Fos- and interleukin-1beta-immunoreactive cells within the corticothalamic projection

A unilateral microinjection of tumor necrosis factor alpha (TNFalpha) (150 ng) onto the primary somatosensory cortex induces state-dependent asymmetries in electroencephalographic (EEG) slow wave activity during non-rapid eye movement sleep in rats [H. Yoshida, Z. Peterfi, F. Garcia-Garcia, R. Kirkpatrick, T. Yasuda, J.M. Krueger, State-specific asymmetries in EEG slow wave activity induced by local application of TNF alpha, Brain Res. 1009 (2004) 129-136]. In the current study, analogous TNFalpha injections were performed to determine Fos- and interleukin-1beta (IL1beta) immunoreactivity (IR). A unilateral microinjection of TNFalpha increased the number of Fos- and IL1beta-IR cells in the primary somatosensory cortex relative to the contralateral side that received heat-inactivated TNFalpha. These asymmetric TNFalpha-induced increases in the number of Fos- and IL1beta-IR cells were evident along the outside surface of the cortex (mainly layers II and III) in a restricted rostral to caudal zone. Asymmetrical increases in the number of Fos-IR cells were also observed in the subcortical region that receives the main cortical projection from the somatosensory cortex, the somatic region of the reticular nucleus of the thalamus (reticular thalamus). The IL1beta-IR cells double-labeled with glial fibrillary acidic protein (GFAP), suggesting that many of the IL1beta-IR cells were astrocytes. The number of the IL1beta-IR cells in the reticular thalamus increased significantly ipsilateral to the TNFalpha injection. Current results indicated that Fos- and IL1beta-IR may be utilized to study the functional neuroanatomy involved in the TNFalpha-mediated state-dependent enhancement of EEG slow wave activity.     

肿瘤坏死因子基因与精神分裂症的传递不平衡研究

目的 探讨肿瘤坏死因子-α(TNF-α)基因和肿瘤坏死因子-β(TNF-β)基因与精神分裂症的关系.方法 收集172个广东潮汕地区的精神分裂症核心家系,将172例精神分裂症患者分为偏执型(96例)和非偏执型(76例),用聚合酶链反应-限制性片段长度多态性方法 ,检测所有研究对象的TNF-α的3个多态性位点(-C863A、-G308A、-G238A)和TNF-β+A252G位点的等位基因频率和基因型频率,并进行传递不平衡检验(TDT).结果 (1)单位点TDT检验,TNF-β+A252G位点杂合子父母过多地传递等位基因G给患者(X2=5.49,Pc＜0.05),而TNF-α的3个多态性位点(-C863A、-G308A、-G238A)均未发现传递不平衡.(2)多位点联合进行单体型分析,未显示在精神分裂症核心家系中存在传递不平衡;但在96个偏执型精神分裂症核心家系中,有一种常见单体型[(-863C,-308G,-238G,+252G);X2=7.20,Pc＜0.05]存在偏向传递.结论 在广东潮汕人群中,TNF-α和TNF-β基因与精神分裂症可能存在某些关联,该基因可能是偏执型精神分裂症的易感基因.     

Expression of tumor necrosis factor alpha in the developing nervous system.

We present evidence that tumor necrosis factor alpha (TNF-alpha) is transiently expressed at specific times during embryogenesis in precisely defined areas of the nervous system in two different classes of vertebrates. In murine embryos, TNF-alpha was detected in the brain, neural tube and peripheral mixed spinal nerves. In the chick embryo, TNF-alpha was observed in the brain neuroepithelium and in the developing Purkinje neurons of the cerebellum. Western immunoblot analysis revealed that brain tissue from both mouse and chick embryos contained a 50 kDa protein showing immunoreactivity with anti-TNF-alpha antibody. These results suggest that TNF-alpha participates in the normal development of the vertebrate brain and spinal cord.