Expression of connexin36 in the adult and developing rat brain

The distribution of connexin36 (Cx36) in the adult rat brain and retina has been analysed at the protein (immunofluorescence) and mRNA (in situ hybridization) level. Cx36 immunoreactivity, consisting primarily of round or elongated puncta, is highly enriched in specific brain regions (inferior olive and the olfactory bulb), in the retina, in the anterior pituitary and in the pineal gland, in agreement with the high levels of Cx36 mRNA in the same regions. A lower density of immunoreactive puncta can be observed in several brain regions, where only scattered subpopulations of cells express Cx36 mRNA. By combining in situ hybridization for Cx36 mRNA with immunohistochemistry for a general neuronal marker (NeuN), we found that neuronal cells are responsible for the expression of Cx36 mRNA in inferior olive, cerebellum, striatum, hippocampus and cerebral cortex. Cx36 mRNA was also demonstrated in parvalbumin-containing GABAergic interneurons of cerebral cortex, striatum, hippocampus and cerebellar cortex. Analysis of developing brain further revealed that Cx36 reaches a peak of expression in the first two weeks of postnatal life, and decreases sharply during the third week. Moreover, in these early stages of postnatal development Cx36 is detectable in neuronal populations that are devoid of Cx36 mRNA at the adult stage. The developmental changes of Cx36 expression suggest a participation of this connexin in the extensive interneuronal coupling which takes place in several regions of the early postnatal brain.     

Immunohistochemical examination of the INK4 and Cip inhibitors in the rat neonatal cerebellum: cellular localization and the impact of protein calorie malnutrition

Expression of the cyclin-dependent kinase inhibitors (CKIs) has been linked to the inhibition of cellular proliferation and the induction of differentiation. Based on structure function analysis, two distinct families of CDKIs, the INK4 and the Cip/Kip family have been identified. The INK4 family member p16(Ink4), and the Cip/Kip protein p27(Kip1) have been implicated in normal development of the CNS and cerebellum. Recent studies have suggested a functional inter-dependence between the CKI and the abundance of cyclin D1 in orchestrating growth factor-induced cellular proliferation. The neonatal rat cerebellum undergoes proliferative growth and differentiation, localized to distinct topographical regions and cell types. The cell type and the temporal profile of CKI expression during postnatal cerebellar development had not been described. The current studies determined the specific cerebellar cell types in which the CKIs were expressed during post natal development by co-staining for cell-type specific markers. p16(Ink4a) and p27(Kip1) immunostaining was identified in both neurons and glial cells, increasing progressively between postnatal days 6 to 13 into adulthood. By contrast, neuronal and glial cell p21(Cip1) staining was prominent at days 6-11 and decreased thereafter. Cyclin D1 was expressed in the proliferating external granular cells, with occassional staining in the molecular, and internal granular layers. Dual immunostaining demonstrated cyclin D1 within cells expressing CKI (p16(Ink4a), p21(Cip1),p27(Kip1)). Cerebellar cellular growth arrest, induced by protein-calorie malnutrition, inhibited cyclin D1 protein levels without affecting CKI immunostaining suggesting CKI do not mediate the developmental arrest. These results demonstrate that the CKIs are induced by differentiation cues in specific cell types with distinct kinetics in the developing cerebellum in vivo.     

An adenoviral vector expressing the glucose transporter protects cultured striatal neurons from 3-nitropropionic acid

Considerable interest has focused on the possibility of using gene transfer techniques to introduce protective genes into neurons around the time of necrotic insults. We have previously used herpes simplex virus amplicon vectors to overexpress the rat brain glucose transporter, Glut-1 (GT), and have shown it to protect against a variety of necrotic insults both in vitro and in vivo, as well as to buffer neurons from the steps thought to mediate necrotic injury. It is critical to show the specificity of the effects of any such transgene overexpression, in order to show that protection arises from the transgene delivered, rather than from the vector delivery system itself. As such, we tested the protective potential of GT overexpression driven, in this case, by an adenoviral vector, against a novel insult, namely exposure of primary striatal cultures to the metabolic poison, 3-nitropropionic acid (3NP). We observed that GT overexpression buffered neurons from neurotoxicity induced by 3NP.     

新生儿窒息后血清神经元特异性烯醇化酶与Apgar评分关系分析

目的 :探讨新生儿窒息后血清神经元特异性烯醇化酶 (NSE)浓度与Apgar评分关系。方法 :选择窒息新生儿52例 ,同期健康无窒息对照22例 ,采用免疫放射分析法 (RIA)测定其生后24小时血清NES水平。结果 :(1)1分钟和5分钟Apgar评分时 ,4～7分组与≤3分组之间血清NSE浓度差异均无显著性。 (2)5分钟复苏组、10分钟复苏组、>10分钟复苏组与对照组间血清NSE浓度差异具有统计学意义 (F=6.21,P<0.05)。>10分钟复苏组的血清NSE浓度较10分钟复苏组、5分钟复苏组及对照组明显升高 (P均<0.01)。结论 :新生儿窒息时 ,血清中NSE浓度与Apgar评分关系并非一致 ,而与复苏时间变化一致 ,复苏时间越长 ,NSE升高越明显     

中药加减补阳还五汤保护脊髓神经元的实验研究

目的探讨加减补阳还五汤对实验性脊髓损伤的保护作用。方法取健康SD大白鼠120只，随机分为假手术组、模型组、中药高剂量组、中药低荆量组和尼莫地平组，采用Allen氏法，以288g／em能量造成T9-T11脊髓不完全损伤。假手术组和模型组于手术前1周和术后1h胃肠灌注生理盐水，各治疗组同时胃肠灌注中药或尼莫地平。各组取12只动物于术后24h测定损伤段脊髓组织过氧化物歧化酶（SOD）、丙二醛（MDA）含量和血液流变学；各治疗组另12只动物治疗4周作为损伤后期观察，于第6用处死测定损伤段脊髓神经细胞数、神经元尼氏体平均灰度。结果①假手术组和各药物组SOD和MDA分别显著高于和低于模型组（P〈0．05-0．01）；假手术组和各药物组血液粘度显著低于模型组（P〈0．05-0．01），中药组血液粘度较西药组显著降低（P〈0．05-0．01）。②中药高剂量组、尼莫地平组和假手术组尼氏体平均灰度高于模型组（P〈0．05），中药低剂量组与模型组无显著差异。结论加减补阳还五汤可有效清除损伤脊髓组织自由基、降低血液粘度，从而一定程度阻止脊髓神经细胞尼氏体溶解，保护神经元。     

血清神经元特异性烯醇化酶在缺血性脑卒中患者中的变化及意义

目的通过观察缺血性脑卒患者中血清神经元特异性烯醇化酶(NSE)的动态变化情况,探讨其对患者临床病情监测和预后评估的意义。方法选择2012年3月至2013年6月期间在我院住院治疗的缺血性脑卒患者65例为研究组,并选择同期在我院接受体检的健康者50例为对照组。采用酶联免疫吸附法测定两组患者血清神经元特异性烯醇化酶的动态变化水平。并分析患者血清NSE水平与患者脑损伤程度和预后的关系。结果研究组与对照组入院24h内血清NSE平均水平相比差异显著(t=7.29,P=0.001)。随后在2d、5d和第7d研究组患者血清NSE水平均显著高于对照组,并较24h时亦显著升高(t=21.81,18.56,9.13;P=0.000,0.000.0.001)。入院第2d,脑损伤病情中型重型组患者血清NSE水平与病情轻型组患者比较显著偏高(t=4.06,t=8.58,P=0.002,0.005)。预后不良组患者各时间血清NSE水平检测值均显著高于预后良好组(t=6.46,5.17,6.43,3.83,7.34;P0.05)。结论临床上可以将血清NSE的表达水平作为判断缺血性脑卒患者早期诊断的有力依据和评价预后的重要指标。     

Minocycline prevents the depressive-like behavior through inhibiting the release of HMGB1 from microglia and neurons

BackgroundOur previous study reports the causal role of high mobility group box 1 (HMGB1) in the development of depression; and we find glycyrrhizic acid (GZA) can be a potential treatment for major depressive disorder (MDD) considering its inhibition of HMGB1 activity. This study aims to further explore the exact cell types that release HMGB1 in the hippocampus.MethodsWe detected the effects of microglia conditioned medium on primary astrocytes and neurons. The effects of minocycline on depressive-like behaviors were tested in BABLB/c mice after four weeks of chronic unpredictable mild stress (CUMS) exposure. Furthermore, the immunofluorescence (IF) assays, hematoxylin-eosin (HE) and TUNEL staining were used to observe hippocampal slices to evaluate the release of HMGB1. The cytoplasmic translocations of HMGB1 protein were assayed by western-blot.ResultsExposure to CUMS caused an active release of HMGB1 from microglia and neurons in the hippocampus. After minocycline administration for inhibiting the activation of microglia, both microglia and neurons reduced the release of HMGB1 and the protein level of central and peripheral HMGB1 recovered accordingly. Along with blocking the release of HMGB1, behavioral and cognitive deficits induced by CUMS were improved significantly by minocycline. In addition, the supernatant of primary microglia stimulated the secretion of HMGB1 in primary neurons, not in astrocytes, at 24 h after 4 h-LPS treatment.ConclusionAll the evidence supported our hypotheses that microglia and neurons are the main cell sources of HMGB1 release under CUMS condition, and that the release of HMGB1 by microglia may play an important role in the development of depressive-like behavior.     

低血糖脑病患者外周血清S100β蛋白和神经元特异性烯醇化酶测定及意义

目的探讨低血糖脑病(hypoglycemic encephalopathy,HE)患者外周血清中神经生化标志物S100β蛋白和神经元特异性烯醇化酶(neuron-specific enolase,NSE)水平与神经功能损害程度的相关性。方法纳入HE患者62例(研究组),以及年龄、性别与之匹配的健康志愿者62例(对照组)。搜集受试者的一般资料和疾病信息。应用酶联免疫吸附试验(ELISA)检测两组受试者外周血清中S100β蛋白和NSE的表达水平。分析低血糖持续时间对HE患者血清S100β蛋白和NSE表达水平的影响。采用美国国立卫生研究院卒中量表(National Institutes of Health Stroke Scale,NIHSS)对治疗后3 m HE患者的神经功能进行综合评分。分析HE患者血清S100β蛋白和NSE表达水平与血糖水平、低血糖持续时间、NIHSS评分的相关性,分析NIHSS评分与血糖水平、低血糖持续时间的相关性。结果研究组血清S100β蛋白和NSE表达水平显著高于正常对照组(P<0.01)。随着低血糖持续时间延长,HE患者外周血清S100β蛋白和NSE表达水平持续升高,至24 h后基本达峰值(P<0.05)。HE患者血清S100β蛋白和NSE表达水平与血糖水平呈负相关(P<0.05),与低血糖持续时间呈正相关(P<0.05),与NIHSS评分呈正相关(P<0.05)。NIHSS评分与血糖水平呈负相关(P<0.05),与低血糖持续时间呈正相关(P<0.05)。结论HE患者外周血清中S100β蛋白和NSE的表达水能在一定程度上反映患者神经功能损害的程度,对HE的诊断及预后的判断有一定参考价值。     

脑出血患者血清NSE、S100β蛋白水平变化及其意义研究

目的分析脑出血患者血清神经元特异性烯醇化酶(NSE)、S100β蛋白的变化特征及与患者神经功能缺损程度的关系。方法选取本院收治的100例脑出血患者作为病例组、100例年龄、性别与之匹配的健康人群作为健康组,分别检测病例组入院时、治疗3d后、治疗7d后的血清NSE、S100β蛋白水平,并分析血清NSE、S100β蛋白水平入院时水平与美国国立卫生研究院卒中量表(NIHSS)评分的关系。结果病例组的血清NSE、S100β测定值在入院时、治疗3 d后、治疗7d后均显著的高于对照组且差异有统计学意义(P0.05);病例组患者的血清NSE、S100β测定值在治疗第3天时达到高峰,显著的高于入院时和治疗7d后(P0.05);病例组的患者依据不同出血量分组,结果显示在入院时、治疗3d、治疗7d后,血清NSE、S100β测定值组间比较为出血量≤15ml、患者出血量15~30ml、患者出血量≥30ml差异均具有统计学意义(P0.05);NSE、S100β与NIHSS评分呈现显著的正相关关系(r=0.419、r=0.338)(P0.05)。结论脑出血患者血清NSE、S100β蛋白随着治疗时间发生显著变化,并且与患者神经缺损程度具有一定的关系。     

Cerebrospinal Fluid Antibodies Directed against Neuron-Associated Gangliosides in HIV-1 Infection

Summary Background: Loss of synapses and neurons is a common finding in HIV-1 infection. Since the in vivo infection of neurons by HIV-1 is limited, indirect factors are likely to contribute to the pathogenesis. Patients and Methods: We have analyzed cerebrospinal fluid (CSF) and serum samples from 25 HIV-1-infected individuals (nine with and 16 without CNS complications) and 19 HIV-negative controls with aseptic meningitis or viral encephalitis, for the presence of antibodies directed against the neuron-associated gangliosides GM1, GD1a and GD1b. Results: Positive antibody titers to ≥ 1 of the gangliosides were found in 13/25 HIV-1-infected patients in CSF and in 17/25 in serum. Significant correlations were found between the presence and titers of CSF antibodies against GM1, GD1a, and GD1b. Six out of nine patients with, and 3/16 without neurological complications (p < 0.05) had positive CSF titers of ≥ 1 of the ganglioside antibodies combined with negative serum titers, indicating intrathecal antibody production. In contrast, only 1/19 controls had detectable anti-ganglioside antibodies in the CSF. Conclusion: The results should be interpreted with caution and CSF anti-ganglioside antibody production might be a part of a non-specific intrathecal polyclonal immunoactivation. Nevertheless, autoantibodies directed against neuron-associated gangliosides might be involved in the neuropathogenesis in HIV-1 disease. Received: September 1, 1999 · Revision accepted: February 29, 2000