脊髓水平细胞外信号调节激酶激活参与吗啡依赖的形成及戒断反应的表达

在大鼠吗啡依赖和戒断模型上,采用行为学、免疫组织化学和Western blot方法观察吗啡依赖及戒断大鼠脊髓神经元磷酸化细胞外信号调节激酶（phospho-extracellular signal-regulated kinase,pERK）表达的变化,及鞘内注射促分裂原活化蛋白激酶激酶（mitogen-activated protein kinase kinase,MEK）抑制剂U0126或ERK反义寡核苷酸对吗啡依赖大鼠纳洛酮催促戒断反应、触诱发痛及脊髓神经元pERK表达的影响,探讨脊髓水平pERK在介导吗啡依赖和戒断过程中的作用。结果显示：（1）在吗啡依赖形成过程中,大鼠脊髓胞浆与胞核非磷酸化ERK表达没有改变,但pERK表达逐渐增加,纳洛酮催促戒断后,仍有进一步增加的趋势,戒断1h后,其表达量明显下降,但仍高于对照组。（2）鞘内预先注射MEK抑制剂U0126或ERK反义寡核苷酸能明显抑制吗啡戒断反应和戒断引起的痛觉异常;与行为学结果一致,脊髓背角pERK阳性神经元表达与脊髓胞浆和胞核pERK表达也明显降低。上述结果提示,脊髓水平ERK激活和核转位参与吗啡依赖的形成及戒断反应的表达。     

细胞外信号调节激酶1/2信号通路在慢性哮喘模型大鼠支气管平滑肌细胞迁移功能变化中的调控作用

本研究旨在探讨细胞外信号调节激酶1／2(extracellular signal-regulated kinase,ERK1/2)信号通路在慢性哮喘模型大鼠支气管平滑肌细胞(bronchial smooth muscle cells,BSMCs)迁移能力改变中的调控作用。应用卵清蛋白致敏和雾化方法制备大鼠慢性哮喘模型,体外培养大鼠BSMCs,采用免疫荧光细胞化学、Western blot和RT-PCR方法检测ERK1／2信号通路的表达,分别用平面迁移实验和跨膜迁移实验来评价BSMCs的活动和趋向迁移能力,并比较用和不用ERK1／2信号通路干预剂的差异。Western blot结果显示慢性哮喘模型大鼠BSMCs中总ERK1／2(9．13±0．87)较对照组(4．68±0．59)明显增加,磷酸化ERK1／2(p-ERK1/2)占总ERK1／2的比值(0．55±0．05)较对照组(0．48±0．04)显著提高(n=10,P<0．01)。慢性哮喘组ERK1和ERK2 mRNA的表达(1．83±0．24和1．07±0．11)较对照组(0．58±0．14和0．51±0．12)明显增高(n=10,P<0．01)。在平面迁移实验中,慢性哮喘大鼠BSMCs的迁移最远距离是对照组的(2．9±0．1)倍,在ERK1／2激动剂表皮生长因子(epidermal growth factor, EGF)刺激下增加到(5．0±0．2)倍,而在30μmol／L PD98059的作用后下降到(1．7±0．2)倍。正常对照大鼠BSMCs平面迁移能力对PD98059的反应较慢性哮喘组弱,仅在100μmol／L PD98059的作用下下降到(0．8±0．1)倍。跨膜迁移实验中,慢性哮喘大鼠BSMCs的跨膜迁移细胞是对照组的(1．9±0．1)倍,在EGF刺激下增加到(3．1±0．2)倍,而在30μmol/L PD98059作用后下降到(1.45±0.2)倍。这些结果表明慢性哮喘模型大鼠BSMCs的迁移能力明显增强,ERK1／2信号通路在该功能变化的调控中可能发挥了重要作用。     

细胞外信号调节激酶活化在慢性支气管哮喘大鼠气道平滑肌细胞增殖中的作用

本文旨在探讨细胞外信号调节激酶（extracellular signal-regulated kinase,ERK）在慢性支气管哮喘大鼠气道平滑肌细胞（airway smooth muscle cells,ASMCs）增殖中的作用。建立慢性哮喘大鼠模型,用ERK激动剂表皮生长因子（epidermal growth factor,EGF）和抑制剂PD98059干预慢性哮喘大鼠ASMCs的培养。采用流式细胞仪、四甲基偶氮唑盐（MTT）法、^3H-thymidine（TdR）掺入法和增殖细胞核抗原（proliferating cell nuclear antigen,PCNA）免疫组织化学法检测ASMCs增殖情况,观察ERK信号通路对ASMCs增殖的影响。RT-PCR和Western blot检测ERK mRNA和ERK1／2、磷酸化ERK1／2（p-ERK1／2）蛋白的表达。与正常对照组ASMCs比较,慢性哮喘组ASMCs的G0/G1期细胞所占比例明显减少,S＋G2／M期细胞所占比例增高;吸光度（A490）值、细胞DNA合成量和PCNA阳性表达量均明显增加,ERK mRNA、ERK1／2蛋白、P-ERK1／2蛋白的表达量以及ERK活化率显著增高。经PD98059干预之后,慢性哮喘组ASMCs的S＋G2／M期细胞所占比例、A490值、细胞DNA合成量和PCNA阳性表达量明显降低,ERK mRNA、ERK1／2蛋白、p-ERK1／2蛋白的表达量以及ERK活化率显著降低。经EGF干预后,慢性哮喘组ASMCs的S＋G2／M期细胞所占比例、A490值、细胞DNA合成量和PCNA阳性表达量进一步增高,而这一作用可以被PD98059抑制。以上结果提示,慢性哮喘大鼠ASMCs内源性增殖活性增加,ERK1／2参与其增殖活性的调控,ERK信号通路在哮喘气道重建的ASMCs增殖调控中具有重要作用。     

细胞外信号调节激酶1在大鼠胆汁性肝纤维化形成过程中的含量变化

目的:探讨细胞外信号调节激酶1(ERK1)在肝纤维化形成过程中的含量变化.方法:采用胆总管结扎(BDL)方法建立大鼠胆汁性肝纤维化模型,应用免疫组织化学、Western blotting技术及逆转录聚合酶链式反应(RT-PCR)方法,研究ERK1及其mRNA在肝纤维化不同时期肝组织中的分布及含量的动态变化.结果:正常肝组织有少量ERK1分布,随着肝纤维化的发展,ERK1阳性细胞明显增多;正常大鼠肝组织中有ERK1蛋白表达,造模1～4周明显增多,4周时增加了3.9倍:正常大鼠肝组织中亦有ERK1 mRNA表达,于造模2 d开始上调,造模4周表达最多.结论:肝纤维化形成过程中ERK1及其mRNA含量增加,尤以造模4周最明显.     

细胞外信号调节激酶在小鼠神经干细胞增殖中的作用

本文旨在探讨细胞外信号调节激酶(extracellular signal-regulated kinase 1/2, ERK1/2)对小鼠神经干细胞增殖的影响.分离E14.5小鼠皮层神经干细胞,通过Western blot检测神经干细胞增殖过程中磷酸化ERK1/2的表达情况,以及不同浓度PD98059处理对神经干细胞ERK1/2磷酸化及神经球形成的影响,并用CCK-8法检测PD98059对神经干细胞增殖的影响.结果显示:ERK1/2在体外培养的神经下细胞增殖过程中被激活;PD98059显著抑制ERK1/2磷酸化及神经干细胞的成球率,且存在剂量效应依赖关系;加入PD98059后神经干细胞的生长被抑制.以上结果表明,ERK1/2在小鼠神经干细胞增殖中具有重要的作用,阻断ERK1/2信号通路后可抑制神经干细胞的增殖.     

cAMP反应元件结合蛋白介导磷酸化细胞外信号调节激酶在神经病理性痛形成中的作用

采用行为学、免疫组织化学和Western blot方法,观察鞘内注射细胞外信号调节激酶(extracellular signal-regulate kinase,ERK)信号转导通路阻滞剂对慢性压迫性损伤(chronic constriction injury,CCI)大鼠痛行为及脊髓背角内磷酸化cAMP反应元件结合蛋白(phosphorylated cAMP response-element binding protein,pCREB)和Fos表达变化的影响,探讨ERK／CREB转导通路在神经病理性疼痛中的作用。结果表明,CCI可明显增加双侧脊髓背角pCREB、损伤侧脊髓背角浅层Fos阳性神经元表达,以CCI后3与5d时尤为显著。鞘内沣射促分裂原活化蛋白激酶激酶(mitogen-activated protein kinase kinase,MEK)阻滞剂U0126及ERK反义寡核苷酸在减轻大鼠痛行为的同时,能明显抑制双侧脊髓背角内pCREB的表达,同时,Fos阳性神经元的表达也明显减少。大鼠痛行为及脊髓背角pCREB和Fos的表达在时相上一致。上述结果提示pCREB参与pERK介导的神经病理性疼痛。     

丝裂原活化的细胞外信号调节激酶在金黄色葡萄球菌诱导的U937细胞凋亡中的作用

目的探讨细胞外信号调节激酶（ERK1／2）在金黄色葡萄球菌（简称金葡菌）诱导的人巨噬细胞系U937细胞凋亡中的作用。方法采用AnnexinVFITc／PI双染流式细胞仪检测U937细胞凋亡,用Westernblotting方法分析不同作用时间MEK和ERK1／2的磷酸化水平。预先用不同浓度的PD98059（ERK途径抑制剂）处理U937细胞1h,观察金葡菌感染30min后U937细胞的凋亡情况。结果U937细胞经过金葡菌处理后,发生凋亡,细胞凋亡率呈时间依赖性升高;随着感染时间的延长,MEK和ERK1／2的磷酸化水平逐渐增加,尤以ERK2比较明显。U937细胞的凋亡可被PD98059抑制。结论金葡菌以时间依赖的方式诱导U937细胞凋亡;金葡菌诱导U937细胞凋亡的效应与激活ERK1／2信号转导通路有关。     

细胞外信号调节激酶在乳腺癌组织中的活化

目的：探讨人乳腺癌中细胞外信号调节激酶（Erk2,p42MAP）在蛋白表达水平、mRNA表达水平和激酶活性水平的变化。方法：应用Western-blotting,免疫沉淀、激酶活性测定和RT-PCR方法检测37例人乳腺癌及其周围正常组织的Erk2表达及活性变化。结果：与周围正常组织相比,37例人乳腺癌中Erk2蛋白表达显增加（100％）;其激酶活性亦显增高（75.68％）;在mRNA水平,Erk2的表达亦明显增高;Erk2表达与其活性变化无相关性。结论：人乳腺癌中Erk2蛋白表达、mRNA表达和激酶活性均显高于周围正常组织。提示Erk2参与乳腺癌的信号转导,为乳腺癌的活化信号,可能成为人乳腺癌治疗的新靶点。     

环氧合酶-1抑制剂对术后疼痛大鼠脊髓中ERK表达的影响

目的：探讨术前鞘内注射选择性环氧合酶-1（cyclooxygenase-1）抑制剂SC-560对术后疼痛大鼠机械痛觉超敏以及脊髓中磷酸化ERK（p-ERK）蛋白表达的影响。方法：采用术后疼痛模型,于术后1h通过观察机械缩足反射阈值（MwT）测定术后痛觉超敏情况、免疫组化染色和免疫印迹检测脊髓中p-ERK表达的变化。结果：①术后疼痛大鼠术后1h出现明显痛觉超敏反应,术前鞘内注射SC-560 100μg可以明显抑制术后痛觉超敏;②术后1h大鼠腰段脊髓背角浅层p-ERK免疫组化染色阳性细胞数较正常对照组明显增加,鞘内注射SC-560可明显减少p-ERK阳性细胞数（P〈0．01）;术后1h大鼠腰段脊髓Western blot检测,p-ERK1／2蛋白的表达较正常大鼠均明显增加,鞘内注射9G560可以抑制p-ERK1／2蛋白的表达。结论：鞘内注射CO3X-1抑制剂可以抑制术后疼痛大鼠术后痛觉超敏反应,脊髓水平Ⅱ水可能介导其上述作用。     

p-ERK1／2及ERK2mRNA在哮喘大鼠气道中的表达变化

目的探讨细胞外信号调节激酶在哮喘大鼠气道中表达变化及其对气道平滑肌细胞增殖的影响。观察细胞外信号调节激酶是否参与了哮喘气道重构这一病理过程。方法18只6周龄雄性wistar大鼠随机分为对照组、哮喘组、地塞米松干预组各6只。以腹腔注射10％卵蛋白和1％卵蛋白雾化吸入复制慢性哮喘模型。干预组在每次激发前给予地塞米松干预。用免疫组化与原位杂交法检测p-ERK1／2及ERK2mRNA在不同大鼠肺组织的表达程度,采用图像分析系统进行图象分析。结果（1）哮喘模型组气道壁面积和平滑肌厚度较对照组和干预组显著增加（P〈0．05）。（2）哮喘组p-ERK1／2及ERK2mRNA在大鼠肺组织的表达程度较对照组和干预组显著增加（P〈0．05）。（3）直线相关性分析显示,哮喘组气道壁面积和平滑肌厚度与大鼠肺组织中p-ERK1／2表达水平呈正相关（分别为r=0．858,r=0．848,P均〈0．05）,哮喘组气道壁面积和平滑肌厚度与大鼠肺组织中ERK2mRNA表达水平呈正相关,（分别为r=0．918,r=0．860,P均〈0．05）。结论哮喘大鼠肺组织p-ERK1／2及ERK2mRNA表达上调,并与气道重构密切相关,该结果提示细胞外信号调节激酶可能参与了气道重构中平滑肌的增殖过程。     

大鼠脊髓小胶质细胞P2X4的表达和糖尿病病理性神经痛大鼠炎症反应和疼痛阈值的关系

摘要 目的：探究大鼠脊髓小胶质细胞P2X4的表达和糖尿病病理性神经痛大鼠炎症反应和疼痛阈值的关系。方法：通过高脂饮食结合链脲佐菌素注射诱导糖尿病病理性神经痛大鼠模型并分为3组：对照组（正常大鼠,腹腔注射载体柠檬酸盐缓冲液0.25 mL/kg）,模型组（糖尿病病理性疼痛模型,同上注射,n=15）和抑制剂组（大鼠糖尿病病理性模型,过鞘内导管注射米诺环素）,共28 d。通过MWT评估对机械刺激的手掌反应。通过双极针电极检测实验大鼠的运动神经传导速速。通过蛋白印迹分析P2X4和BDNF蛋白表达。通过RT-PCR分析炎症因子IL-1β、TNF-α和NLRP3的mRNA表达。通过蛋白印迹分析p38MAPK和p-p38MAPK的蛋白表达。结果：第2week、4week和6week,模型组MWT较对照组降低（P<0.05）,抑制剂组MWT较模型组升高（P<0.05）。第2 week,个实验组大鼠MNCV比较无差异（P>0.05）,第4week和第6week,模型组MNCV较对照组降低（P<0.05）,抑制剂组MNCV较模型组升高（P<0.05）。模型组P2X4和BDNF蛋白表达较对照组升高（P<0.05）,抑制剂组P2X4和BDNF蛋白表达较模型组降低（P<0.05）,模型组P2X4和BDNF mRNA表达较对照组升高（P<0.05）,抑制剂组P2X4和BDNF mRNA表达较模型组降低（P<0.05）。模型组IL-1β、TNF-α和NLRP3的mRNA表达较对照组升高（P<0.05）,抑制剂组IL-1β、TNF-α和NLRP3的mRNA表达较抑制剂组降低（P<0.05）。模型组p-p38MAPK蛋白表达较对照组升高（P<0.05）,抑制剂组p-p38MAPK蛋白表达较模型组降低（P<0.05）,各实验组大鼠p38MAPK蛋白表达无差异（P>0.05）。结论：大鼠脊髓小胶质细胞P2X4-BDNF信号在DNP中起重要作用,并且P2X4在DNP期间激活的脊髓小胶质细胞中表达升高,抑制小胶质细胞激活能显著降低P2X4表达和炎症水平,可防止热痛觉过敏并增加大鼠疼痛阈值。     

大鼠内侧前额叶皮质内ERK1/2 活化参与脊髓损伤后抑郁情绪

目的:观察细胞外信号调节激酶1/2(ERK1/2)的活化在脊髓损伤引起抑郁中的作用。方法:应用Western blot和行为药理学方法,观察脊髓损伤后(SCI)大鼠内侧前额叶皮质内(mPFC)ERK1/2及磷酸化-ERK1/2(p-ERK1/2)的表达情况及ERK1/2磷酸化抑制剂U0126对抑郁样行为的影响。结果:脊髓损伤后的第2天到第8周,SCI模型大鼠的BBB评分均显著低于假手术组,差异具有统计学意义(p0.05)。脊髓损伤后8周-12周,SCI模型大鼠强迫游泳不动时间与假手术组相比明显缩短,mPFC内pERK1/2蛋白表达水平明显升高,总ERK 1/2的蛋白水平则未见组间差异,而给予U0126的大鼠的不动时间与给药之前相比明显延长增加,mPFC内pERK1/2蛋白表达水平较SCI模型大鼠明显降低,差异均具有统计学意义(P0.05)。结论:内侧前额叶皮质内ERK1/2的激活参与了脊髓损伤后引起的突触可塑性,在相关的抑郁样行为的产生中发挥了重要的作用。     

Locomotor Dysfunction and Pain: The Scylla and Charybdis of Fiber Sprouting After Spinal Cord Injury

Injury to the spinal cord (SCI) can produce a constellation of problems including chronic pain, autonomic dysreflexia, and motor dysfunction. Neuroplasticity in the form of fiber sprouting or the lack thereof is an important phenomenon that can contribute to the deleterious effects of SCI. Aberrant sprouting of primary afferent fibers and synaptogenesis within incorrect dorsal horn laminae leads to the development and maintenance of chronic pain as well as autonomic dysreflexia. At the same time, interruption of connections between supraspinal motor control centers and spinal cord output cells, due to lack of successful regenerative sprouting of injured descending fiber tracts, contributes to motor deficits. Similarities in the molecular control of axonal growth of motor and sensory fibers have made the development of cogent therapies difficult. In this study, we discuss recent findings related to the degradation of inhibitory barriers and promotion of sprouting of motor fibers as a strategy for the restoration of motor function and note that this may induce primary afferent fiber sprouting that can contribute to chronic pain. We highlight the importance of careful attentiveness to off-target molecular- and circuit-level modulation of nociceptive processing while moving forward with the development of therapies that will restore motor function after SCI.     

阿米替林对脊髓电刺激治疗幻肢痛疗效的影响

目的：本研究旨在探讨阿米替林干预对脊髓电刺激（SCS）治疗幻肢痛疗效的影响。方法：研究对象为2007年1月至2009年6月在我科行SCS置入术且符合入组标准并自愿参加研究的幻肢痛患者,共获7例。术后SCS均开启,阿米替林治疗在术后1个月时开始。疼痛、情绪、生活质量评估采用视觉模拟评分法（visual analogue scales,VAS法）,现时疼痛强度评分法（presentpain intensity。PPI）,综合性医院焦虑抑郁量表（The Hospital Anxiety and Depression Scale,HAD）,疼痛失能指数（Pain disability index,PDI）。结果：（1）开启SCS后患者的疼痛、抑郁焦虑情绪及生活质量均得到显著改善。（2）所有患者在使用阿米替林治疗以后疼痛、情绪及生活质量也显著改善。结论：阿米替林能显著提高SCS对幻肢痛的疗效。     

Role of Extracellular Signal-Regulated Protein Kinases 1 and 2 in Oligodendroglial Process Extension

Abstract: The relationship between extracellular signal-regulated protein kinase (ERK) activation and process extension in cultured bovine oligodendrocytes (OLGs) was investigated. Process extension was induced through the exposure of cultured OLGs to phorbol 12-myristate 13-acetate (PMA), an activator of protein kinase C (PKC), for various intervals. During the isolation of these OLGs from bovine brain, the original processes were lost. Therefore, any reinitiation of process extension via PMA stimulation was easily discernible through morphological monitoring. It was found that exposure of OLGs to PMA for 10 min was enough to induce OLG process extension 24–72 h later. Furthermore, this extension was still evident at least 1 week after the initial PMA stimulation, indicating that OLGs do not need continuous PKC activation to sustain process extension. Control and PMA-stimulated OLGs were also subjected to immunocytochemistry using an anti-ERK antibody selective for the mitogen-activated protein kinases p42 Erk2 (ERK2) and p44 Erk1 (ERK1) isoforms. ERK immunoreactivity in the nucleus was evident after PMA stimulation of OLGs but not in control OLGs. In parallel experiments, the control and PMA-stimulated OLGs were purified by Mono Q fractionation and subjected to ERK phosphotransferase assays using [γ-³²P]ATP and either myelin basic protein (MBP) or a synthetic peptide substrate based on the Thr⁹⁷ phosphorylation site in MBP. These assays indicated that in PMA-treated OLGs, ERK activation was at least 12-fold higher than in control OLGs. Anti-ERK and anti-phosphotyrosine western blots of the assay fractions verified an enhanced phosphorylation of ERK1 and ERK2 in PMA-treated fractions relative to control fractions. When OLGs were pretreated for 15 min with the ERK kinase (MEK) inhibitor PD 098059 before PMA stimulation, they exhibited a 67% decrease in ERK activation as compared with cells treated with PMA alone. Furthermore, these MEK inhibitor-pretreated cells were still viable but showed no process extensions up to 1 week later. Therefore, we propose that a threshold level of ERK activity is required for the initiation of OLG process extension.     

阿米替林对脊髓电刺激治疗幻肢痛疗效的影响

目的:本研究旨在探讨阿米替林干预对脊髓电刺激(SCS)治疗幻肢痛疗效的影响。方法:研究对象为2007年1月至2009年6月在我科行SCS置入术且符合入组标准并自愿参加研究的幻肢痛患者,共获7例。术后SCS均开启,阿米替林治疗在术后1个月时开始。疼痛、情绪、生活质量评估采用视觉模拟评分法(visualanaloguescales,VAS法),现时疼痛强度评分法(presentpainin-tensity,PPI),综合性医院焦虑抑郁量表(The Hospital Anxiety and Depression Scale,HAD),疼痛失能指数(Pain disability index,PDI)。结果:(1)开启SCS后患者的疼痛、抑郁焦虑情绪及生活质量均得到显著改善。(2)所有患者在使用阿米替林治疗以后疼痛、情绪及生活质量也显著改善。结论:阿米替林能显著提高SCS对幻肢痛的疗效。     

Spinal Astrogliosis in Pain Models: Cause and Effects

Pathological pain has been subjected to intense research to shed light on the underlying mechanisms of key symptoms, such as allodynia and hyperalgesia. The main focus has by and large concerned plasticity of spinal cord neurons and the primary afferent nerves relaying peripheral information to the spinal cord. Animal pain models display an increased presence of reactive astrocytes in the spinal cord, but in contrast to neurons, little is known about how they contribute to abnormal pain sensation. However, astrocytes are now beginning to receive greater attention, and as new information is emerging, it appears that astrocytes undertake critical roles in manifesting pathological pain. Through the secretion of diffusible transmitters, such as interleukins, ATP, and NO, astrocytes may augment primary afferent neuronal signaling or sensitize second order neurons in the spinal cord. In addition, astrocytes might lead to altered pain perception by a direct modulation of synaptic transmission between neurons in the nociceptive pathway or through the creation of astrocytic networks capable of transducing signals for extended distances across and along the spinal cord. Future research in astrocyte activation and signaling may therefore reveal novel drug targets for managing pathological pain.     

ERK活化对哮喘大鼠气道重塑及CyclinD1表达的影响

目的探讨细胞外信号调节蛋白激酶（ERK）对哮喘大鼠气道重塑及CyclinD1表达的作用。方法原代培养大鼠的平滑肌细胞（ASMCs）,给予ERK激动剂表皮生长因子EGF和抑制剂PD98059干预ASMCs生长,依处理方式不同分为5组：（1）正常对照组（2）哮喘对照组;（3）E组：EGF20 ng/mL;（4）P＋E组,PD98059 10μmol/L1 h后添加EGF 20 ng/mL;（5）PD组,PD98059 10μmol/L。采用四甲基偶氮唑盐（MTT）法检测气道平滑肌细胞（ASMCs）增殖能力,流式细胞术（FCM）测定细胞周期和cyclinD1的蛋白含量,RT-PCR方法检测cyclinD1mRNA表达水平。结果（1）与哮喘对照组比较,E组ASMCs S＋G2/M期比例、吸光度A值、cyclinD1蛋白阳性表达率和cyclinD1 mRNA的A值均显著升高,PD组均显著降低（P〈0.05）。P＋E组与哮喘对照在此4项指标上比较无明显差异。（2）哮喘（对照组、E组、PD组和P＋E组）组与正常对照组,其S＋G2/M期比例、吸光度A值、cyclinD1蛋白和cyclinD1 mRNA的表达均显著增高（P〈0.05）。结论ERK活性促进哮喘大鼠ASMCs的增殖,增加cyclinD1在哮喘平滑肌细胞中的表达,导致气道重塑的形成,提示ERK可能对CyclinD1的表达具有调节作用。     

Spatiotemporal Expression of Dexras1 After Spinal Cord Transection in Rats

Dexras1, a brain-enriched member of the Ras subfamily of GTPases, as a novel physiologic nitric oxide (NO) effector, anchor neuronal nitric oxide synthase (nNOS) that increased after spinal cord injury (SCI), to specific targets to enhance NO signaling, and is strongly and rapidly induced during treatment with dexamethasone. It is unknown how the central nervous system (CNS) trauma affects the expression of Dexras1. Here we used spinal cord transection (SCT) model to detect expression of Dexras1 at mRNA and protein level in spinal cord homogenates by real-time PCR and Western blot analysis. The results showed that Dexras1 mRNA upregulated at 3 day, 5 day, and 7 day significantly (P < 0.05) that was consistent with the protein level except at 7 day. Immunofluorescence revealed that both neurons and glial cells showed Dexras1 immunoreactivivty (IR) around SCT site, but the proportion is different. Importantly, injury-induced expression of Dexras1 was co-labeled by caspase-3 (apoptotic marker) and Tau-1 (marker for pathological oligodendrocyte). Furthermore, colocalization of Dexras1, carboxy-terminal PSD95/DLG/ZO-1 (PDZ) ligand of nNOS (CAPON) and nNOS was observed in neurons and glial cells, supporting the existence of ternary complexes in this model. Thus, the results that the transient high expression of Dexras1 which localized in apoptotic neurons and pathological oligodendrocytes might provide new insight into the secondary response after SCT. Xin Li, Chun Cheng, and Min Fei contributed equally to this work.