沉默circROBO1通过下调KRAS抑制鼻咽癌CNE2细胞侵袭与肺转移

目的探讨沉默环状RNA hsa_circ_0124696(circROBO1)对鼻咽癌CNE2细胞侵袭与肺转移的影响机制。 方法qRT-PCR检测鼻咽癌及癌旁组织中circROBO1表达。采用干扰小RNA(siRNA)沉默鼻咽癌CNE2细胞中circROBO1的表达,Transwell及HE染色检测circROBO1对CNE2细胞迁移能力和体内肺转移的影响。TargetScan在线软件预测circROBO1下游miR-217与下游靶基因KRAS的靶向结合位点,双荧光素酶报告基因实验验证两者之间的靶向调控关系。蛋白免疫印迹检测siRNA沉默CNE2细胞中circROBO1表达对KRAS的影响。 结果鼻咽癌组织中circROBO1表达高于癌旁组织(P＜0.05)。与转染si-circNC的对照组相比,si-circROBO1组鼻咽癌CNE2细胞侵袭与体内肺转移能力均显著降低(P＜0.05)。circROBO1下游miR-217与KRAS之间存在靶向结合位点,并且circROBO1可影响KRAS的蛋白和mRNA表达量。 结论沉默circROBO1通过miR-217下调KRAS抑制鼻咽癌CNE2细胞侵袭与肺转移。     

Involvement of adenylate cyclase and protein kinase C in the α2-adrenoceptor-mediated inhibition of noradrenaline and 5-hydroxytryptamine release in rat hypothalamic slices

Summary In superfused rat hypothalamic slices prelabelled with [³H]-noradrenaline, the ₂-adrenoceptor agonist UK 14304 inhibited in a concentration-dependent manner the electrically-evoked release of tritium. This inhibition was antagonized by the ₂-adrenoceptor blocking agent idazoxan, which by itself increased the electrically-evoked tritium overflow. Exposure to forskolin, an adenylate cyclase activator, increased the electrically-evoked release of [³H]-noradrenaline. In the presence of forskolin (1 mol/l), both the inhibitory effect of UK 14304 and the increasing effect of idazoxan on the electrically-evoked release of [³H]-noradrenaline were less pronounced than in the absence of the adenylate cyclase activator. Exposure to forskolin and to the phosphodiesterase inhibitor 3-isobutyl-l-methylxanthine shifted to the right the concentration-effect curve for UK 14304 in a similar manner as that observed in the presence of forskolin alone. Exposure to phorbol-12,13-dibutyrate (0.01–10 mol/l), a drug which activates protein kinase C, increased the electrically-evoked release of [³H]-noradrenaline. In the presence of phorbol-12,13-dibutyrate (0.1 and 1 mol/l), the concentration effect curve for UK 14304 on tritium overflow was significantly shifted to the right. The increasing effect of idazoxan on tritium overflow was significantly less pronounced in the presence of 1 mol/l phorbol-12,13-dibutyrate.In superfused rat hypothalamic slices prelabelled with [³H]-5-hydroxytryptamine, the ₂-adrenoceptor agonist UK 14304 significantly inhibited the electrically-evoked release of tritium. Exposure to forskolin increased in a concentration-dependent manner [³H]-5-hydroxytryptamine overflow, but did not modify the UK 14304-mediated inhibition. Exposure to 3-isobutyl-1-methylxanthine enhanced the electrically-evoked release of [³H]-5-hydroxytryptamine. In the presence of both forskolin (1 mol/l) and 3-isobutyl-l-methylxanthine (1 mmol/l), the concentration-response curve for UK 14304 was significantly shifted to the right. Exposure to phorbol-12,13-dibutyrate (0.01–10 mol/l) enhanced in a concentration-dependent manner the electrically-evoked overflow of [³H]-5-hydroxytryptamine. In the presence of phorbol-12,13-dibutyrate (0.1 and 1 mol/l), UK 14304 was significantly less potent to inhibit tritium release than in the absence of the protein kinase C activator.It is concluded that both cyclic AMP and phosphoinositide turnover are involved in the modulation of noradrenaline and 5-hydroxytryptamine release by presynaptic ₂-adrenoceptors in rat hypothalamic slices. However, these interactions do not represent definitive proof for a cause-effect relationship for the second messengers mediating the ₂-adrenoceptor induced inhibition of transmitter release either as autoreceptor or as heteroreceptor.Send offprint requests to S. Z. Langer at the above address     

Decreased prefrontal 5-HT2A receptor binding in subjects at enhanced risk for schizophrenia

The brain serotonin-2A receptor (5-HT_2AR) has been implicated in both the pathology of schizophrenia and the therapeutic action of atypical antipsychotics. However, little is known about the 5-HT_2AR status before the onset of schizophrenia and before the exposure to antipsychotics. We used [¹⁸F] altanserin and positron emission tomography (PET) in a pilot study of 6 individuals suspected to be at elevated risk for schizophrenia and seven age-matched controls to test the hypothesis that regional 5-HT_2AR binding is altered in the prodromal stages of schizophrenia. Distribution volume ratios (DVRs) as a proxy for 5-HT_2AR availability were significantly reduced in prefrontal cortex regions of at-risk subjects, implicating early abnormalities of serotonergic neurotransmission that antecede the onset of schizophrenia.     

IL-18 Receptor Expression on Epithelial Cells is Upregulated by TNF Alpha

IL-18 is a multifunctional cytokine that augments both innate and acquired immunity and potentiates Th1 and Th2 reactions. We studied the expression of IL-18 receptor (IL-18R) on renal and respiratory epithelial cell lines. Both cell lines upregulated IL-18R mRNA and IL-18R membrane expression in response to TNF alpha and other proinflammatory cytokines. The function of IL-18R was confirmed by induction of IL-8 release from epithelial cells in response to recombinant IL-18. Epithelial cells may represent an important target for IL-18, mainly under inflammatory conditions associated with TNF alpha release.     

鼠巨细胞病毒抑制神经干细胞分化及分化基因表达的体外研究

目的 研究鼠巨细胞病毒(MCMV)感染对体外培养神经干细胞(NSCs)分化及分化基因表达的影响,探讨CMV先天感染致神经损伤的机制.方法 体外分离培养和鉴定BALB/c胎鼠NSCs并检测其分化潜能,用感染复数(MOI)为5、1和0.1的MCMV Smith毒株感染NSCs并进行分化培养,倒置显微镜下观察细胞形态学改变,流式细胞术检测分化细胞比率,免疫荧光法观察NSCs及其分化细胞标记物Nestin、胶质纤维酸性蛋白(GFAP)和神经元特异性烯醇化酶(NSE)表达的变化,采用MCMV早期抗原(EA)示踪感染过程(MOI=1),real-time RT-PCR检测分化早期NSCs Wnt信号途径关键分化基因Wnt-3和Wnt-Ta mRNA水平的动态变化.结果 体外培养的NSCs呈球样生长,神经干细胞特异性标记Nestin表达阳性,并可进一步诱导分化为NF-200阳性的神经元和GFAP阳性的星形胶质细胞;分化培养后,感染组NSCs不能贴壁分化生长并逐渐出现肿胀,细胞Nestin表达下调缓慢并显著高于正常对照组,而GFAP和NSE表达显著低于正常对照组(P<0.05),可检测到MCMV EA的阳性表达;分化培养3-9 d,感染组Nestin阳性细胞比率显著高于正常对照组,GFAP和NSE阳性细胞比率显著低于正常对照组(P<0.05);感染组Wnt-3 mRNA水平在分化培养后第1～2天显著低于正常对照组(P<0.05),感染组Wnto-7a mRNA水平在第0.5～2天明显低于正常对照组(P<0.05);感染组和正常对照组的差异随病毒MOI的增加而更加明显.结论 MCMV感染可明显抑制NSCs向神经元和星形胶质细胞方向分化,导致分化细胞比率减少;下调或干扰NSCs wnt信号途径分化基因wnt-3和Wnt-7a的表达;抑制NSCs分化及其分化基因表达的效应与MOI大小存在一定量效依赖关系;MCMV可能通过抑制NSCs分化基因的表达来抑制其分化,这可能是CMV先天感染致脑发育异常的重要机制之一.     

PET/CT在肿瘤疾病中的初步应用

目的回顾性探讨PET／CT对肿瘤的诊断价值。方法肿瘤病人200例，其中未治疗病人71例，已治疗病人129例。经静脉注射^18F-FDG 45min后，进行PET／CT扫描。结果未治疗病人71例中，PET／CT准确诊断有68例（95．7％），阴性3例，发现肿瘤转移54例，其中广泛转移30例。已治疗组129例中，提示肿瘤复发或／伴转移96例，其余33例在手术／放疗／化疗等治疗后未见肿瘤复发。结论PET／CT具有对病变部位进行精确定位和定性的优势，大大提高了诊断的准确率。对于肿瘤的早期诊断和分期、指导制定治疗方案、判断肿瘤有无复发与坏死及预后的估计均有重要的临床意义。     

牛IL-18基因的克隆及遗传进化分析

目的：克隆牛白细胞介素18（IL-18）全基因，并对其进行序列分析。方法：从ConA刺激培养的牛外周血淋巴细胞提取总RNA，利用巢式RT-PCR方法扩增出牛IL-18全长cDNA，将其克隆到pMDl8-T载体上，测序后进行序列分析。结果：成功地克隆到了牛IL-18全基因，序列分析表明，实验中所克隆到的牛IL-18序列与GeneBank所登录的牛IL-18核苷酸序列及其推导氨酸序列同源性分别是99．5％和99％。与人、猕猴、野猪、山羊属、马等核苷酸序列及其推导氨基酸序列同源性分别在84．9％-99．5％和74．9％～99％之间，研究结果在国内还未见报道。结论：成功地从牛外周血中克隆到了牛IL-18的基因，其全长为598bp。