鞘内注射p38 MAPK抑制剂对神经病理性疼痛大鼠脊髓背角脑源性神经营养因子表达的影响

目的 观察鞘内注射p38 MAPK抑制剂SB203580对坐骨神经压缩性损伤(CCI)神经病理性疼痛大鼠的镇痛效果及脊髓背角p38丝裂原活化蛋白激酶(p38 MAPK)、脑源性神经营养因子(BDNF)的表达,探讨大鼠神经病理性疼痛可能的发生机制。 方法 30只SD雄性大鼠随机分为3组(n=10):假手术组、对照组(CCI组)、SB203580组(CCI术前30 min及术后第1~3天鞘内注射SB203580,剂量为0.1 ml/kg)。于CCI术前2 h以及术后第4~14天测定大鼠右足机械痛阈值;术后第14天取损伤侧腰段脊髓,采用免疫组化方法观察脊髓背角p38 MAPK及BDNF的表达。结果 与术前相比,假手术组术后机械痛阈值差异无统计学意义,对照组、SB203580组在CCI术后机械痛阈值明显降低(P<0.05);与假手术组相比,CCI术后,对照组、SB203580组机械痛阈值明显降低(P<0.05);与对照组相比,CCI术后第4~14天SB203580组机械痛阈值明显升高(P<0.05)。与假手术组相比,对照组、SB203580组脊髓背角p38 MAPK表达及BDNF释放明显增加(P<0.05);与对照组相比,SB203580组损伤侧脊髓背角p38 MAPK表达及BDNF释放明显降低(P<0.05)。结论 鞘内注射p38 MAPK抑制剂可能通过降低损伤侧脊髓背角p38 MAPK表达,抑制BDNF释放,从而缓解CCI大鼠慢性神经病理性疼痛。     

新生鼠高氧肺损伤中p38MAPK的磷酸化

目的 探讨p38丝裂素活化蛋白激酶(p38 mitogen-activated protein kinase,p38MAPK)在新生鼠高氧肺损伤中的表达及意义.方法 160只新生鼠分为空气对照组、高氧肺损伤组、高氧肺损伤 SB203580组和高氧肺损伤 生理盐水组,分别建立动物模型.在12、24、72 h和1周4个时相点处死,进行肺组织病理学检查、肺湿/干重比值(W/D)测定、Western blot法检测p38MAPK的表达.结果 高氧暴露72 h即可建立肺损伤模型.新生鼠暴露于高氧12h后,p38MAPK开始表达,72h达高峰,后逐渐降低.在高氧暴露72 h后,空气对照组未见p38MAPK表达,高氧肺损伤组可见p38MAPK表达;高氧肺损伤 生理盐水组p38MAPK表达明显强于高氧肺损伤 SB203580组.结论 p38MAPK参与了新生鼠高氧肺损伤的过程,SB203580可以减轻这种损伤.     

阿尔茨海默大鼠嗅球p38MAPK的表达

目的 观察阿尔茨海默(AD)大鼠嗅球p38MAPK的表达,探讨p38MAPK在AD病理改变发生中的作用机制.方法 采用大鼠侧脑室注射Aβ25-35建立AD动物模型,Y迷宫实验测定行为学变化,免疫组化染色法检测建模后4 d、7 d和14 d时AD组、生理盐水组、抑制剂组和抑制剂对照组p38MAPK在大鼠嗅球中的表达.结果 ①建模后7 d、14 d AD组大鼠行为学测试出现明显改变,学会训练次数(N)、完成所有反应中错误反应的次数(EN)及全天总反应时间(TRT)均较生理盐水组增加(P<0.05),抑制剂组较AD组N、EN和TRT均有明显改善.②AD组在建模后4 d,嗅球出现明显的p38MAPK表达,且随时间的延长表达增加(P<0.05),与生理盐水组比较,AD组p38MAPK阳性细胞数明显升高(P<0.01).抑制效组p38MAPK的表达在3个时间点,较AD组、抑制剂对照组均明显下降(P<0.01).结论 Aβ25-35可激活痴呆大鼠嗅觉中枢p38MAPK信号转导通路,p38MAPK可能参与了AD早期嗅觉障碍的形成过程.p38MAPK抑制剂SB203580能部分减弱A1325-35的神经毒性作用.     

苦参煎与SB203580对p38MAPK信号传导通路的调控影响

目的:探讨苦参煎与SB203580对p38MAPK信号传导通路的调控影响。利用苦参煎与SB203580抑制p38 MAPK信号传导通路,来证明中药对基因转录表达具有一定的调控作用。方法:模拟血管内膜损伤术,采用ELISA方法检测188只Webster大鼠血清中P38MAPK的水平含量。将其随机平均分为正常对照组、假手术组、生理盐水组、苦参煎组和SB203580组。结果与结论:中药苦参煎有着与SB203580相同的功效,即对P38MAPK的显著抑制作用。所以对血管内皮有比较明确的保护作用,能干扰MAPK信号传导通路,既能减轻内皮损伤后的炎性细胞释放反应,也能使再生的内皮某些功能得到恢复,有利于内皮细胞结构和功能恢复,防止炎性因子对细胞的损害。     

TNF-α 通过 p38 丝裂原活化蛋白激酶信号通路对小胶质细胞HMGB1 表达的调控作用

目的：观察P38丝裂原活化蛋白激酶(p38 mitogen-activated protein kinase,p38 MAPK)抑制剂SB203580对 TNF-α诱导的原代培养大鼠小胶质细胞高迁移率族蛋白B1(high mobility group protein B1,HMGB1)表达的影响。方法： 采用原代培养大鼠小胶质细胞,设立对照组、TNF-α组(25 ng/mL)、TNF-α(25 ng/mL)+SB 203580组(10 μmol/L)、SB 203580组(10 μmol/L),各组细胞经药物处理16 h后分别用ELISA法检测细胞培养上清中HMGB1的表达情况,Western 印迹检测细胞HMGB1和磷酸化p38MAPK表达情况,用反转录PCR检测HMGB1 mRNA表达。结果：经TNF-α刺激 后,大鼠小胶质细胞及其培养上清液中HMGB1蛋白表达增高;SB 203580可抑制TNF-α诱导的磷酸化p38 MAPK表达 (P<0.01),同时下调HMGB1mRNA和HMGB1蛋白的表达。结论：TNF-α可诱导小胶质细胞晚期炎症因子HMGB1的表 达,并且其诱导机制与p38 MAPK被快速激活相关。     

Coronary microembolization induced myocardial contractile dysfunction and tumor necrosis factor-α mRNA expression partly inhibited by SB203580 through a p38 mitogen-activated protein kinase pathway

Background  The microemboli produced during spontaneous plaque rupture and ulceration and during coronary intervention will reduce coronary reserve and cause cardiac dysfunction. It is though that inflammation caused by the microinfarction induced by the microembolization may play an essential role. It is known that the activation of p38 mitogen-activated protein kinases (MAPK) in both infected and non-infected inflammation in myocardium may cause a contractile dysfunction. But the relation between the activation of p38 MAPK and microembolization is still unknown.

Methods  Sprague-Dawley rats were randomly divided into three groups: Sham group, coronary microembolization (CME) group and SB203580 group (n=10 per group). CME rats were produced by injection of 42 μm microspheres into the left ventricle with occlusion of the ascending aorta. SB203580, a p38 MAPK inhibitor, was injected into the femoral vein after the injection of microspheres to make the SB203580 group. Left ventricular ejection fraction (LVEF) was determined by echocardiography. The protein concentration of P38 MAPK in the myocardium was assessed by Western blotting. The relative expression of mRNA for tumor necrosis factor (TNF)-α was assessed by the technique of semi-quantitative polymerase chain reaction amplification.  

Results  LVEF was depressed at three hours up to 12 hours in the CME group. Increased p38 MAPK activity and TNF-α mRNA expression were observed in the CME group. The administration of SB203580 partly inhibited p38 MAPK activity, but did not fully depress the TNF-α expression, and partly preserved cardiac contractile function.

Conclusions  p38 MAPK is significantly activated by CME and the inhibition of p38 MAPK can partly depress the TNF-α expression and preserve cardiac contractile function.

     

p38MAPK参与去甲肾上腺素预处理的延迟保护作用

目的 探讨p38MAPK(丝裂素活化蛋白激酶)是否参与去甲肾上腺素(NE)预处理的延迟保护作用。方法 建立大鼠心肌缺血/再灌注损伤(I/R)模型。分别应用去甲肾上腺素、p38的特异性抑制剂SB203580预处理心脏,24h后对心脏进行缺血再灌注,观察此时心肌梗塞范围、血浆乳酸脱氢酶(LDH)活性,同时用western blotting方法检测NE预处理后即刻、10 min、15 min、30 min时p~(38)磷酸化水平。结果 NE预处理明显缩小心梗范围,减轻血浆LDH活性升高程度(P<0.01 vs I/R)。p38磷酸化在NE预处理后即刻稍微增高,10min轻度升高,15min达到高峰,30min开始下降。用SB203580可明显抑制p38磷酸化,而心梗范围、血浆LDH活性同单纯缺血/再灌注组相似(P>0.05)。结论 ①去甲肾上腺素预处理对24h后缺血/再灌注心肌有保护作用。②p38参与心肌预处理后的延迟保护作用,去甲肾上腺素预处理后p38短暂而快速的激活可能是药物延迟保护作用的重要机制之一。     

p38丝裂原激活蛋白激酶抑制剂对脓毒症早期大鼠心肌中炎性因子和细胞凋亡蛋白表达的影响

 目的 探讨脓毒症时心肌损害的原因及p38丝裂原激活蛋白激酶(MAPK)抑制剂的保护作用。方法 将84只雄性SD大鼠随机分为对照组、实验组和治疗组（n=28）。实验组和治疗组采用腹腔注射内毒素（10 mg/kg）制作脓毒症模型,治疗组同时加p38MAPK抑制剂SB203580予以干预,对照组腹腔注射生理盐水。在不同时间点观察大鼠血清脑钠素（BNP）、肿瘤坏死因子α(TNF-α)、白细胞介素6（IL-6）的浓度及心肌组织中TNF-α、IL-6、凋亡蛋白caspase-9的表达情况。 结果 实验组大鼠血清TNF-α、IL-6进行性升高。对照组心肌组织中仅有微量TNF-α、IL-6及caspase-9表达,而实验组心肌组织中则大量表达。血清TNF-α、IL-6浓度及心肌中caspase-9的表达与心肌损害程度呈显著正相关。应用SB203580后,治疗组血清TNF-α、IL-6浓度显著降低,心肌中caspase-9的表达也减少。但各组血清BNP浓度之间差异无统计学意义,均在正常范围之内。结论 TNF-α、IL-6的大量释放及其在心肌中的表达是脓毒症心肌损害的原因之一,p38MAPK抑制剂SB203580可对脓毒症大鼠心肌损害起保护作用。     

Role of p38 mitogen-activated protein kinases in cardioprotection of morphine preconditioning

Background p38 mitogen-activated protein kinases (MAPK) in ischemic preconditioning (IPC) may be essential to cardioprotection. We assessed whether protective effect of morphine-induced preconditioning (MPC) on myocardial ischemia and reperfusion injury in rat hearts involved p38 MAPK activation. Methods Male Spargue-Dawley rats (weighing 300－350 g) were randomly assigned to 1 of the following 8 groups: control (CON, saline vehicle, n=9), SB 203580 (SB, a p38 MAPK inhibitor, n=6), MPC (n=6), IPC (n=9), SB+MPC, SB+IPC, MPC+SB, and IPC+SB (n=6). Infarct sizes (IS), a percentage of the area at risk (AAR), were determined by triphenyltetrazolium (TTC) staining. Tissue samples were processed from the entire AAR of left ventricle for the determination of p38 MAPK protein expression (5 hearts/group). The bands representing the proteins were visualized using an enhanced chemiluminescence detection system. Results The IS/AAR was significantly reduced by IPC (12.9±1.6)% or MPC (25.3±2.9)% compared to the control (52.7±5.5)%. SB 203580 administered prior to preconditioning abolished the effect of IPC (SB+IPC: (43.8±2.6)%, P&gt;0.05 vs CON, P&lt;0.01 vs IPC), but not MPC (SB+MPC: (30.7±0.9)%, P&lt;0.01 vs CON, P&gt;0.05 vs MPC). Treatment with SB 203580 prior to sustained ischemia diminished the protective effect of both MPC (MPC+SB: (42.4±2.9)%, P&gt;0.05 vs CON) and IPC (IPC+SB: (52.0±2.5)%, P&gt;0.05 vs CON) on IS/AAR. In the IPC group, phospho-p38 MAPK protein increased significantly within 5 minutes into ischemia and remained elevated at 30 minutes into reperfusion, while phospho-p38 MAPK protein in the MPC group only increased significantly at 30 minutes into reperfusion. Conclusion The activation of p38 MAPK just acts as a mediator of MPC,whereas it acts as both a trigger and a mediator in IPC.     

SB203580对干燥综合征(SS)小鼠泪腺分泌功能的干预研究

 目的 观察干燥综合征(Sjgren’s syndrome,SS)小鼠泪腺组织注射p38丝裂原活化激酶(p38 mitogen-activated protein kinases,p38MAPK)通路抑制剂SB203580后对小鼠干眼的改善情况,以探索今后临床治疗SS干眼的新方法。方法 选用20只雌性BALB/c小鼠(10~20周龄)和20只雌性MRL/lpr小鼠(18周龄),将BALB/c小鼠随机分为空白对照组和不同作用时间的实验组;MRL/lpr小鼠分为空白对照组和不同浓度SB203580注射组。Western blot法检测IL-1β对BALB/c小鼠泪腺作用不同时间后P-p38 MAPK的表达;不同浓度SB203580对MRL/lpr小鼠泪腺组织注射7天后检测酚红棉丝试验、泪膜破裂时间(BUT)、荧光素染色情况,光谱分析法检测注射前后泪腺组织乙酰胆碱和去甲肾上腺素表达量,并进行组织病理学检查。结果 随着BALB/c小鼠泪腺在10 ng/mL IL-1β中孵育时间延长,P-p38 MAPK的表达量逐渐增加;空白对照组MRL/lpr小鼠泪液分泌功能低下,泪膜破裂时间短,角膜荧光素染色评分高,经SB203580注射后,泪液分泌逐渐增加,泪膜破裂时间延长,角膜荧光素染色范围显著缩小,泪腺组织乙酰胆碱和去甲肾上腺素分泌量较空白对照组显著增多;病理切片显示,与空白对照组相比,SB203580注射组淋巴细胞浸润程度显著减轻。结论 IL-1β下游p38MAPK通路激活在SS小鼠干眼的发病中有重要作用,阻断p38MAPK通路对SS小鼠干眼有一定疗效。