Tumor necrosis factor-α induces sensitization of meningeal nociceptors mediated via local COX and p38 MAP kinase actions

The proinflammatory cytokine TNF-α has been shown to promote activation and sensitization of primary afferent nociceptors. The downstream signaling processes that play a role in promoting this neuronal response remain however controversial. Increased TNF-α plasma levels during migraine attacks suggest that local interaction between this cytokine and intracranial meningeal nociceptors plays a role in promoting the headache. Here, using in vivo single unit recording in the trigeminal ganglia of anesthetized rats, we show that meningeal TNF-α action promotes a delayed mechanical sensitization of meningeal nociceptors. Using immunohistochemistry, we provide evidence for non-neuronal localization of the TNF receptors TNFR1 to dural endothelial vascular cells and TNFR2 to dural resident macrophages as well as to some CGRP-expressing dural nerve fibers. We also demonstrate that meningeal vascular TNFR1 is co-localized with COX-1 while the perivascular TNFR2 is co-expressed with COX-2. We further report here for the first time that TNF-α evoked sensitization of meningeal nociceptors is dependent upon local action of cyclooxygenase (COX). Finally, we show that local application of TNF-α to the meninges evokes activation of the p38 MAP kinase in dural blood vessels that also express TNFR1 and that pharmacological blockade of p38 activation inhibits TNF-α evoked sensitization of meningeal nociceptors. Our study suggests that meningeal action of TNF-α could play an important role in the genesis of intracranial throbbing headaches such as migraine through a mechanism that involves at least part activation of non-neuronal TNFR1 and TNFR2 and downstream activation of meningeal non-neuronal COX and the p38 MAP kinase.     

Short term exendin-4 treatment reduces markers of metabolic disorders in female offspring of obese rat dams

ObjectivesMaternal obesity imposes significant health risks in the offspring including diabetes and dyslipidemia. We previously showed that the hypoglycaemic agent exendin-4 (Ex-4) administered from weaning can reverse the maternal impact of ‘transmitted disorders’ in such offspring. However daily injection for six-weeks was required and the beneficial effect may lapse upon drug withdrawal. This study aimed to investigate whether short term Ex-4 treatment during suckling period in a rodent model can reverse transmitted metabolic disorders due to maternal obesity.MethodsMaternal obesity was induced in female Sprague Dawley rats by high-fat diet feeding for 6 weeks, throughout gestation and lactation. Female offspring were treated with Ex-4 (5 μg/kg/day) between postnatal day (P) 4 and 14. Female offspring were harvested at weaning (P20). Lipid and glucose metabolic markers were measured in the liver and fat. Appetite regulators were measured in the plasma and hypothalamus.ResultsMaternal obesity significantly increased body weight, fat mass, and liver weight in the offspring. There was an associated inhibition of peroxisomal proliferator activated receptor gamma coactivator 1α (PGC1α), increased fatty acid synthase (FASN) expression in the liver, and reduced adipocyte triglyceride lipase (ATGL) expression. It also increased the plasma gut hormone ghrelin and reduced glucagon-like peptide-1. Ex-4 treatment partially reversed the maternal impact on adiposity and impaired lipid metabolism in the offspring, with increased liver PGC1α and inhibition of FASN mRNA expression. Ex-4 treatment also increased the expression of a novel fat depletion gene a2-zinc-glycoprotein 1 in the fat tissue.ConclusionShort term Ex-4 treatment during the suckling period significantly improved the metabolic profile in the offspring from the obese mothers at weaning. Long-term studies are needed to follow such offspring to adulthood to examine the sustained effects of Ex-4 in preventing the development of metabolic disease.     

天然罗汉松二萜体外抗登革病毒活性研究

登革病毒(dengue virus,DENV)是造成热带和亚热带地区登革热和登革出血热季节性大爆发的蚊媒病原体,可导致严重威胁生命的疾病,因此亟需研发DENV疫苗和药物.本研究发现从石栗枝叶中分离的罗汉松型二萜(3α,5β,10α)-13-methoxypodocarpa-8,11,13-triene-3,12-dio...     

STAT3 表达与肿瘤血管生成及放射敏感性关系的研究进展*

信号转导和转录活化因子3（STAT3）属于STATs 家族中重要一员,广泛表达于不同类型的细胞和组织中,并参与细胞生长、增殖、凋亡、恶性转化等生理和病理过程的调控。近年来,STAT3 在肿瘤血管生成及放疗敏感性方面的研究日益增多。研究表明STAT3 活化后,一方面通过直接调控血管内皮生长因子（VEGF）表达促进血管生成进而产生放疗抗拒;另一方面STAT3 通过活化缺氧诱导因子- 1α（HIF-1α）间接促进血管生成产生放疗耐受。此外,STAT3 还可以直接或通过HIF-1α 间接调控细胞周期蛋白D 1（CyclinD1）表达,使细胞周期由G 1 期快速进入S 期,促进细胞增殖,且CyclinD1 与放疗敏感性相关。由此发现,STAT3 通过直接和间接两种途径在肿瘤血管生成及放疗抗拒方面发挥作用。本文拟对此方面的相关研究新进展作一综述。     

JAK2/STAT3信号通路对A549细胞株中HIF-1ɑ、VEGF蛋白表达的影响

目的：研究人肺腺癌细胞A549细胞中JAK2/STAT3信号通路对HIF-1ɑ、VEGF蛋白表达的影响。方法：AG490处理在氧含量正常及缺氧条件下（CoCl2200μmol/L）48h后Westernblot法测定A549细胞中HIF-1ɑ、VEGF蛋白表达变化（分组为对照组、AG49050μmol/L、AG490100μmol/L、CoCl2、CoCl2＋AG49050μmol/L和CoCl2＋AG490100μmol/L组）。IL-6（3.85nmol/L）处理A549细胞24h后,检测细胞中STAT3、p-STAT3、HIF-1ɑ、VEGF蛋白表达变化（分组为对照组,IL-6组）。结果：JAK2特异性抑制剂AG490作用48h后,相对于对照组AG490能够下调HIF-1ɑ、VEGF的蛋白表达,且呈浓度依赖性;随浓度的升高,抑制作用更明显。缺氧条件下（CoCl2200μmol/L）能够上调HIF-1ɑ、VEGF的蛋白表达。AG490也能够下调CoCl2诱导的HIF-1ɑ、VEGF的蛋白表达,且呈浓度依赖性,随浓度的升高,抑制作用更显著。IL-6能够上调HIF-1ɑ、VEGF的蛋白表达。结论：在人肺腺癌细胞A549细胞中,缺氧可上调HIF-1α和VEGF蛋白表达。JAK2/STAT3信号通路对HIF-1α和VEGF蛋白的表达具有调节作用。     

重力打击式小鼠外伤性视神经病变模型的建立及外伤性视神经病变发病机制的探讨

目的 通过建立重力打击式小鼠外伤性视神经病变模型探讨外伤性视神经病变的发病机制.方法 选取SPF级C57BL/6J成熟小鼠48只(96眼),均取小鼠左眼为实验眼进行造模,右眼为对照眼不做处理.采用重力打击建立小鼠外伤性视神经病变模型,造模后第1、3、5、7天对小鼠进行观察,每个时间点取6只小鼠进行闪光视觉诱发电位检查、...     

瑞苏伐他汀对2型糖尿病大鼠心肌的保护作用及其机制

目的：探讨瑞苏伐他汀对2型糖尿病大鼠心肌病变的防治作用及其作用机制.方法：STZ注射诱导制备T2DM大鼠模型,成功模型随机分为对照组（B组,n=25）、瑞苏伐他汀组（C组,n=25）,并设正常对照组（A组,n=10）.于第14周末取大鼠心脏,称取心脏质量并计算心脏肥厚指数（HWI）,胶原容积分数（CVF）,电镜观察心肌超微结构; 应用免疫组化法检测过氧化物酶体激活物受体α（PPARα）在心肌组织中的表达.结果：B组大鼠表现出心肌病特征,HWI,CVF增加,电镜观察可见大鼠心肌纤维以变性坏死为主,肌丝纤维丢失,肌丝排列紊乱,间质胶原纤维增多,糖原、脂褐素沉积等病理改变,C组大鼠心肌病变较B组有所减轻,HWI,CVF下降,免疫组化图像分析显示,B组大鼠心肌PPARα蛋白表达比A组明显升高,C组大鼠PPARα蛋白表达比B组明显升高,差别均具有统计学意义（均P〈0.01）.结论：瑞苏伐他汀在调脂的基础上,通过提高心肌PPARα的表达,对T2DM的心肌病变具有保护作用.     

缺血缺氧脑损伤大鼠IL-6和TNF-α的变化及其临床意义

目的：探讨缺血缺氧脑损伤大鼠白介素-6（IL-6）和肿瘤坏死因子-α（TNF-α）的动态变化及其临床意义。方法：90只Wistar大鼠随机分为对照组和实验组,再将实验组按造模后4h、8h、12h、24h和48h不同时点分为5个亚组。利用夹闭双侧颈总动脉,并进行缺氧的方法制备模型。以放射免疫分析（RIA）测定血清和脑组织中IL-6和TNF-α的变化。结果：造模后48h内,血清和脑组织中IL-6和TNF-α的水平呈动态变化。实验组中各亚组的两者含量均明显高于对照组（P〈0.01或P〈0.05）。血清和脑组织中两者分别在24h和12h时达到峰值。结论：缺血缺氧后不同时点IL-6和TNF-α的含量呈动态变化;两者可作为缺血缺氧后脑组织损伤程度及修复的临床指标。     

基于TCGA数据库挖掘恶性脑胶质瘤乏氧与免疫微环境相关预后价值基因

目的 挖掘恶性脑胶质瘤中与乏氧诱导因子-1α（hypoxia inducible factor-1α,HIF-1α）表达存在相关性的免疫通路或基因,并进一步分析其对脑胶质瘤预后的影响。方法 从肿瘤基因组图谱（the cancer genome atlas,TCGA）数据库提取脑胶质瘤HIF-1α基因表达谱数据,采用R语言分析HIF-1α基因与其他基因之间的相关性,通过GO和KEGG数据库对差异表达基因进行功能注释,包括细胞组分、生物学过程、分子功能及相关信号通路。并采集了74例人脑胶质瘤组织进一步验证分析。结果 TCGA数据库中共收集到169例脑胶质瘤患者的数据,其中与HIF-1α基因有相关性的基因有455个。对455个满足条件的相关性基因进行GO和Pathway富集分析,共得到66个KEGG Pathway;最终发现基因TNFRSF1α的P值具有统计差异。进一步对比分析TCGA数据库169例脑胶质瘤患者与529例非肿瘤患者数据中TNFRSF1α表达的情况。结果 提示TNFRSF1α与HIF-1α在脑胶质瘤组织中显著高于癌旁组织。且人脑胶质瘤组织TNFRSF1α表达水平与胶质瘤的病理分级正相关。结论 KEGG通路发现TNFRSF1α基因与乏氧有关,提示TNFRSF1α基因可能与乏氧共同影响脑胶质瘤患者的预后。     

杂色曲霉素对小鼠小脑Purkinje细胞TNF-α和TGF-β2 mRNA表达的影响

本研究观察了杂色曲霉素(sterigmatocystin,ST)对小鼠Purkinje细胞TNF-α和TGF-β2 mRNA表达的影响。给予BALB/c小鼠一次灌胃ST(3000μg/kg),分别于灌胃后0.5、1、2、4、8和16h处死动物,用原位杂交方法观察了Purkinje细胞TNF-α和TGF-β2 mRNA的表达。TNF-α和TGF-β2mRNA在对照组和处理组各时间点的Purkinje细胞均有阳性表达。但各处理组与对照组比较,TNF-α和TGF-β2 mRNA表达显著增加(P<0.01)。上述结果说明单次ST灌胃后TNF-α和TGF-β2 mRNA在Purkinje细胞表达明显增加,TNF-α和TGF-β2在ST对脑组织的损伤过程中起着重要的作用。