ERK和JNK通路在沙土鼠脑缺血预处理中的表达及作用

目的探讨ERK和JNK在沙土鼠脑缺血预处理中的表达及作用。方法采用沙土鼠前脑缺血再灌注损伤模型。随机分为假手术组(SH)、预处理对照组(IC)、预处理缺血组(IP)及脑缺血再灌注组(IR);各组根据再灌注15 m in、2 h、4h、6 h、1 d、3 d、5 d及7 d又分8个亚组。在预定时间点行开阔法行为学检查、TUNEL法海马CA1/3区凋亡细胞检测、免疫组织化学SP法测定p-ERK、p-JNK在海马区的变化。结果IP可减少沙土鼠探索活动及海马CA1区凋亡锥体细胞数量(vsIR,P<0.01)各组CA1区p-ERK无表达,IR组海马CA1区p-JNK表达较强,再灌后1d最为明显,IP可明显减弱CA1区p-JNK的表达(vsIR,P<0.01),明显增强CA3区p-ERK的表达(P<0.05,P<0.01)。结论脑缺血可导致ERK及JNK在海马各亚区的差异性表达。缺血预处理可能通过抑制CA1区JNK磷酸化、增强CA3区ERK活性而保护海马细胞。     

JNK信号通路与缺血再灌注损伤的相关性研究进展

缺血再灌注损伤(ischemia-reperfusion injury,IRI)是一种重要的临床问题,在缺血性疾病和器官移植等疾病的治疗过程中常见。随着研究的发现,对组织造成损伤的主要因素不是缺血本身,而是恢复血供以后,大量的组织细胞死亡。实验证明,JNK(c-Jun N-termianlkinase)参与了细胞的凋亡,在IRI的病理变化中起重要作用。因此,JNK信号通路与IRI具有高度的相关性,通过调节JNK信号通路可作为治疗IRI的新的靶点。本文对JNK信号通路以及与IRI的相关性研究进行综述。     

缺血预处理对肝脏缺血——再灌注损伤的保护作用机制及应用

随着肝脏外科的发展，在临床上肝移植术越来越多地应用于多种肝脏疾病。肝门阻断、选择性半肝血流阻断、全肝血流阻断等一系列外科技术的应用，以及肝移植、休克等过程中，均遇到肝脏缺血再灌注(Ischemia／reperfusion，I／R)损伤问题。如何提高肝脏的自我保护能力，调动其内源性的保护机制，目前已成为肝脏外科发展的方向和热点。本文就近年来国内、     

缺血预处理联合后处理的肺保护作用研究进展

近年来,体外循环术、肺移植术、肺栓塞溶栓治疗术等技术水平的日渐成熟,然而肺缺血再灌注损伤仍然是最常见的术后并发症,造成患者术后肺功能不全,严重者甚至可造成患者死亡。随着缺血预处理和缺血后处理概念的提出,为再灌注肺损伤的保护方法提供了新的理论基础和研究方向。本文就预处理联合后处理的肺保护作用综述其研究进展。     

肢体缺血预处理对大鼠肝缺血-再灌注损伤的延迟性保护作用

目的观察肢体缺血预处理(LIPC)对大鼠肝缺血-再灌注(I-R)损伤的延迟性保护作用。方法雄性SD大鼠36只,随机分为对照组(S组),I-R组,LIPC组,每组12只。S组仅行开腹,不作其他处理;I-R组行肝缺血1h,再灌注3h;LIPC组先行双后肢缺血5min,反复3次24h后行肝缺血1h,再灌注3h。手术完毕,腹主动脉采血用于检测总超氧化物歧化酶(T-SOD)、丙二醛(MDA)、血清ALT与AST;切取肝组织,测定肝脏的湿干比(W/D),免疫组化检测肿瘤坏死因子α(TNF-α)的表达,同时光电镜观察肝组织显微、超微结构的变化。结果与I-R组比较,LIPC组T-SOD活性增加(P<0.01),MDA水平、ALT、AST、W/D值及TNF-α的阳性表达均明显降低(P<0.01),肝脏的显微及超微结构损伤减轻。结论 LIPC对大鼠肝脏I-R损伤有明显的延迟性保护作用。其机制可能与增加机体抗氧化能力、抑制肝脏炎症反应、减轻肝脏水肿、抑制TNF-α的表达和改善肝组织微循环有关。     

预处理对肝脏的保护作用

目的　评价缺血预处理 (IPC)对大鼠肝脏的保护作用。方法　在原位灌注的大鼠肝脏缺血再灌注模型上观察 IPC的保护作用。结果　预处理可阻止血清丙氨酸转氨酶 (AL T)、天冬氨酸转氨酶 (AST)、乳酸脱氢酶 (L DH)及脂质过氧化物 (L PO)水平增高 ,而使组织超氧化歧化酶 (SOD)保持在较高水平。结论　缺血预处理对大鼠肝脏有保护作用     

下肢缺血预处理对大鼠肺缺血-再灌注损伤的保护作用

目的 研究下肢缺血预处理在大鼠肺组织缺血-再灌注(I-R)损伤中的作用及机制.方法 18只SD大鼠随机均分为假手术(A组)、I-R(B组)和下肢缺血预处理十I-R(C组)三组.实验结束时,取肺组织测定湿/干重比(W/D)、超氧化物歧化酶(SOD)、髓过氧化物酶(MPO)活性和丙二醛(MDA)含量,观察肺组织病理学变化;ELISA法检测血清肿瘤坏死因子α(TNF-α)、白细胞介素1β(IL-1β)和IL-6含量.结果 与B组比较,C组肺组织W/D、MPO活性和MDA、TNF-α、IL-1β、IL-6的含量均明显降低(P＜0.05),SOD活性升高(P＜0.05).光镜下C组肺组织病理学改变较B组明显减轻.结论 下肢缺血预处理可以通过抑制大鼠肺组织I-R后炎症细胞的聚集、氧自由基的产生和促炎细胞因子TNF-α、IL-1β、IL-6的释放而减轻肺I-R损伤.     

缺血预处理和缺血后处理联合应用对肝脏缺血-再灌注损伤的保护作用

目的 探讨缺血预处理和缺血后处理联合应用对肝脏缺血-再灌注(I-R)损伤的保护作用.方法 采用大鼠部分肝缺血模型,将SPF级雄性SD大鼠40只随机分为5组,每组8只:假手术(S)组,缺血-再灌注(I-R)组.缺血预处理(IPre)组,缺血后处理(IPost)组,缺血预处理+后处理(IPre+IPost)组.全面复流120 min后收集肝脏组织和血液标本,检测血清ALT,肝组织ATP、MDA和RCR,做肝组织病理检查.结果 IPre+IPost组血清ALT、肝组织MDA显著低于其余各组(P<0.05);IPre+IPost组肝组织ATP、RCR高于其余各组(P<0.05);病理结果:IPre+IPost组肝组织损伤轻于其余各组.结论 IPre和IPost联合应用能更好的保护线粒体,维持组织的能量代谢稳定,从而在再灌注早期更好的减轻肝脏的损伤.     

L-精氨酸复合缺血预处理对肢体缺血再灌注损伤的保护作用

为探讨L-精氨酸复合缺血预处理对肢体缺血再灌注损伤的保护作用，将75例需要上止血带充气止血的择期手术病人随机分为5组各15例：A组(缺血再灌注)；B组(上止血带前10min和松止血带前10min各静滴L-精氨酸150mg/kg)；C组(在B组处理基础上于术后5h静滴L-精氨酸150mg/kg)；D组(缺血前阻断血流5min，复流5min，重复3次)；E组(并用C、D两组处理)。各组止血带阻断下肢血流1-1．5h。分别于缺血前、再灌注45min、术后6h、术后24h抽术侧股静脉血，检测血浆肌酸磷酸激酶(CK)、丙二醛(MDA)水平。结果表明与缺血前比较，随着肢体血流的恢复，血浆CK及MDA的值逐渐升高，以术后6h最显著；但B、C、E组45min及D、E组术后24h的变化无显著性意义。C、D、E组与A组相应时段相比，CK和MDA均有显著性下降(P&;lt;0．05、P&;lt;0．01)。E组与C、D组相比亦有显著性下降。结论：L-精氨酸与缺血预处理合并应用对肢体再灌注损伤的保护作用优于单独应用。     

参麦及缺血预处理对大鼠肝缺血再灌注损伤的保护作用

目的:研究参麦注射液及缺血预处理对肝缺血再灌注损伤的保护作用.方法:64只Wistar大鼠随机分成4组:假手术组(sham-operation,SO);缺血再灌注组(ischemia reperfusion,IR);缺血预处理组(ischemic preconditioning,IPC);参麦组(Shengmai injection,SM).建立肝脏缺血再灌注损伤模型.SO组行剖腹假手术;IR、IPC、SM组于再灌注60 min 、90 min时分别随机取8只大鼠检测血清谷丙转氨酶(ALT)、谷草转氨酶(AST)、乳酸脱氢酶(LDH)和白细胞介素6(IL-6),同时取肝组织制成匀浆检测金属硫蛋白(MT),SO组于相应时点取样检测相同指标.分析比较各组计量资料.结果:SM组及IPC组在再灌注60 min、90 min时ALT、AST、LDH、IL-6水平均低于IR组(P＜0.01),而金属硫蛋白水平均高于IR组.结论:参麦及缺血预处理对肝缺血再灌注损伤具有保护作用.     

Effect of a new calcium entry blocker, NB-818, on delayed neuronal death in the ischemic gerbil hippocampus

The effect of NB-818, a new dihydropyridine calcium entry blocker, on delayed neuronal death (DND) in the hippocampal CA1 subfield of gerbils after 5 minutes of forebrain ischemia induced by bilateral carotid artery occlusion was examined. Gerbils were treated intraperitoneally with NB-818 (0.1-3 mg/kg) just after release of the occlusion. Four days after the ischemia, they were fixed by perfusing 10% buffered-formalin, and the neuronal cell density (NCD, cell/mm) in the CA1 subfield was estimated under microscopy. The average NCD in the ischemic control group was 43 +/- 10.8 cells/mm, whereas NB-818 (3 mg/kg) significantly ameliorated DND with an average NCD of 143 +/- 24.2 cells/mm (P less than 0.01). In addition, NB-818 (3 mg/kg) significantly inhibited DND at 1, 2 and 4 weeks after transient ischemia: the average NCD of the NB-818 and ischemic control groups were 80 +/- 9.4 (P less than 0.01) and 43 +/- 7.7 cells/mm, 92 +/- 13.7 (P less than 0.05) and 52 +/- 9.3 cells/mm, and 57 +/- 5.0 (P less than 0.01) and 43 +/- 12.4 cells/mm, respectively. In this experiment, NB-818 exhibited a protective effect on DND in the hippocampal CA1 subfield after transient forebrain ischemia, and its effect persisted for up to 4 weeks. These findings suggest that NB-818 may be useful for clinical treatment of neurological deficit after an ischemic insult.     

缺血预适应在缺血性脑卒中患者神经功能中的保护作用

目的　研究缺血预适应在缺血性脑卒中患者神经功能中的保护作用及疗效。方法　选取2019年6月至2021年6月聊城市第三人民医院收治的110例缺血性脑卒中患者,进行前瞻性随机平行对照研究,采用随机数字表法将患者分为A组和B组,每组55例。A组男23例,女32例;年龄52～74（62.78±4.77）岁;B组男27例,女28例;年龄51～73（61.48±4.59）岁。B组采用常规药物治疗,A组在B组的基础上采用远隔缺血后适应治疗。比较两组临床疗效,治疗前、治疗3个月后美国国立卫生研究院卒中量表（NIHSS）、日常生活能力Barthel指数（BI）评分及梗死灶体积、血清S100蛋白（S100β）、神经元特异性烯醇化酶（NSE）、新喋呤（Npt）、半乳糖凝集素3（GAL3）、血液流变学指标（血浆黏度、全血高切黏度、全血低切黏度、纤维蛋白原）水平。计数资料采用χ²检验,计量资料采用t检验。结果　治疗3个月后,A组临床总有效率为94.55%（52/55）,高于B组的81.82%（45/55）,两组比较,差异有统计学意义（χ²=4.274,P=0.039）;治疗3个月后,A组NIHSS评分为（9.74±1.83）分,低于B组的（12.25±2.82）分,BI评分为（75.26±5.38）分,高于B组的（62.47±6.02）分,两组比较,差异均有统计学意义（t=5.496、11.748,均P<0.001）;治疗3个月后,A组梗死灶体积为（3.35±1.02）cm³,缩小幅度优于B组［（3.79±1.11）cm³］,差异有统计学意义（P<0.05）;治疗3个月后,A组全血低切黏度为（5.08±0.79）mPa·s、全血高切黏度为（4.22±0.51）mPa·s、血浆黏度为（1.17±0.34）mPa·s、纤维蛋白原为（2.86±0.34）g/L,均低于B组的（6.63±1.02）mPa·s、（4.85±0.62）mPa·s、（1.36±0.40）mPa·s、（3.53±0.42）g/L,两组比较,差异均有统计学意义（均P<0.05）;治疗3个月后,A组血清S100β为（1.37±0.38）μg/L、NSE为（15.28±3.37）μg/L、Npt为（6.95±1.78）nmol/L、GAL3为（9.68±2.27）g/L,均低于B组的（1.74±0.46）μg/L、（19.72±4.73）μg/L、（9.07±2.24）nmol/L、（11.94±3.04）g/L,两组比较,差异均有统计学意义（均P<0.05）。结论　缺血预适应辅助治疗缺血性脑卒中患者可进一步提升疗效,可有效改善患者日常生活能力及神经功能,缩小梗死灶体积,调节血液流变学状态,促进病情恢复。     

The role of c-Jun N-terminal kinase in the A beta-mediated impairment of LTP and regulation of synaptic transmission in the hippocampus

The effects of the beta-amyloid peptide (Abeta) fragment 25-35 were investigated on hippocampal synaptic transmission and long-term potentiation (LTP) in vitro. Abeta([25-35]) was found to impair both post-tetanic potentiation (PTP) and LTP in the hippocampal CA1. The anthra[1,9-cd]pyrazol-6(2H)-one, SP600125, was used to inhibit c-Jun N-terminal kinase (JNK) activity, which is believed to mediate cell death. Prior application of SP600125 attenuated the Abeta([25-35])-mediated impairment of PTP and LTP, when measured from the pre-drug baseline. In the presence of SP600125 alone, we observed an increase in baseline synaptic transmission and reduction in paired-pulse facilitation, consistent with an increase in synaptic transmission. There was no alteration in the level of PTP and LTP obtained, when measured from the pre-drug baseline. In the presence of both SP600125 and Abeta, however, PTP was greatly enhanced compared with controls. We therefore suggest that the activation of the JNK signalling pathway mediates the effects of Abeta on synaptic plasticity. Our data also indicate that endogenous JNK activity may regulate neurotransmitter release in the hippocampal CA1 in vitro.     

肢体缺血预处理通过激活有丝分裂原激活蛋白激酶p38减轻脑缺血导致的大鼠海马CA1区神经元凋亡和脑水肿(英文)

目的旨在探讨肢体缺血预处理(LIP)能否减轻脑缺血过程中海马CA1区神经元凋亡和脑水肿。方法72只永久凝闭椎动脉的Wistar大鼠随机分为6组:假手术,LIP(双侧股动脉夹闭10min,间歇10min,3次循环),脑缺血,LIP+脑缺血,DMSO和SB 203580+LIP+脑缺血组。各组大鼠中6只在脑缺血后3d处死,TUNEL染色计数凋亡细胞;6只在脑缺血后24h处死,测定脑组织含水量。结果TUNEL染色显示,假手术和LIP组海马CA1区偶有TUNEL阳性细胞;脑缺血组海马CA1区可见大量棕黄色着色的TUNEL阳性细胞,与假手术组及LIP组相比,细胞数量明显增加;LIP+脑缺血组,TUNEL阳性神经元数与脑缺血组相比明显减少,提示LIP明显抑制缺血引起的海马CA1区锥体细胞凋亡;有丝分裂原激活蛋白激酶p38拮抗剂SB 203580+LIP+脑缺血组,海马CA1区阳性染色锥体细胞明显增加,与DMSO+LIP+脑缺血组相比有显著性差别,表明SB 203580可拮抗LIP抑制凋亡的作用。与假手术和LIP组比较,脑缺血组脑组织含水量明显增加,表明LIP降低了脑缺血引起的脑组织含水量增加;LIP前应用SB 203580可抑制LIP的脑保护作用,使脑组织含水量较LIP+脑缺血组显著增加。结论LIP能够减轻脑缺血过程中海马CA1区神经元凋亡和脑水肿,可能与活化有丝分裂原激活蛋白激酶p38有关。     

沙利度胺对肺纤维化大鼠肺组织中c-jun氨基末端激酶及α-平滑肌肌动蛋白表达的影响及意义

目的观察沙利度胺在大鼠肺纤维化中的干预作用及对磷酸化c-jun氨基末端激酶(p-JNK)及α-平滑肌肌动蛋白(α-SMA)表达的影响,进一步分析沙利度胺在肺纤维化过程中可能的作用机制。方法将54只健康雄性Wistar大鼠随机分为对照组、模型组、沙利度胺组,每组各18只,于气管内滴注博莱霉素注射液制备肺纤维化模型,对照组给予气管内滴注0.9%氯化钠注射液。沙利度胺组于造模当日起给予沙利度胺(100mg/kg)灌胃,对照组和模型组给予等量0.9%氯化钠注射液,每日1次。各组分别于第7、14、28天随机处死6只大鼠,取肺组织行苏木素-伊红(HE)染色和Masson染色,碱水解法测大鼠肺组织羟脯氨酸(Hyp)含量,免疫组织化学法测肺组织中p-JNK蛋白及α-SMA的表达。结果模型组第7天时肺泡炎症明显,第28天时可见明显纤维化改变;随着时间的推移,羟脯氨酸含量呈逐渐上升趋势,第28天时含量最高;p-JNK蛋白及α-SMA的表达较对照组明显增加。沙利度胺组与模型组比较,肺泡炎症及纤维化程度均有所减轻;第14、28天时Hyp含量有所降低,p-JNK蛋白及α-SMA的表达有所减少(P<0.05);模型组α-SMA与p-JNK蛋白含量呈正相关。结论沙利度胺可减轻博莱霉素所致大鼠肺纤维化的程度,其机制可能是通过抑制p-JNK蛋白的活化及α-SMA的表达实现的。     

Involvement of c-jun N-terminal kinase in G2/M arrest and caspase-mediated apoptosis induced by cardiotoxin III (Naja naja atra) in K562 leukemia cells.

Cardiotoxin III (CTX III), a basic polypeptide with 60 amino acid residues isolated from Naja naja atra venom, may have a potentiality as a structural template for rational drug design in killing cancer cells. Treatment of K562 cells with 0.3 microM of CTX III resulted in G2/M phase cell cycle arrest that was associated with a marked decline in protein levels of G2/M regulatory proteins including cyclin A, cyclin B1, Cdk2 and Cdc25C. In contrast to no effect on the phosphorylation of ERK, p38 MAPK and Akt, an activation of JNK was noted when K562 cells were exposed to CTX III. CTX III-mediated G2/M phase arrest and apoptosis were reduced by treatment with the JNK-specific inhibitor SP600125, but not by ERK and p38MAPK inhibitors. Further investigation showed that the specific JNK inhibitor, SP600125, reduced the activation of caspase-3, caspase-9, and reversed the decline in the expression of cyclin B1. Taken together, our data show for the first time that JNK, but not ERK, p38MAPK or Akt signaling, plays an important role in CTX III-mediated G2/M arrest and apoptosis in K562 cancer cells.     

Role of adenosine in renal protection induced by a brief episode of ischemic preconditioning in rats.

The protective effect of a brief episode of ischemic preconditioning was examined at an early phase of ischemic-reperfusion injury in the rat kidney. Rats were subjected to 50 min of left renal artery occlusion followed by 120 min of reperfusion. Ischemic preconditioned rats were subjected to preconditioning with two cycles of 3-min ischemia and 5-min reperfusion (IPC). Ischemic-reperfusion injury led to a low recovery of the glomerular filtration rate (GFR). Overt morphological changes, consisting of blood trapping and tubular collapse, were seen. IPC improved the recovery of GFR and renal morphology. The IPC effect was not blocked by 8-(p-sulfophenyl)-theophylline (SPT), a non-selective adenosine receptor antagonist, by 1,3-dipropyl-8-cyclopentylxanthine (DPCPX), a selective A1-receptor antagonist, or by 3,7-dimethyl-1-propargylxanthine (DMPX), a selective A2-receptor antagonist. Intravenous infusion of adenosine (30 microg/min per rat, for 5 min) prior to the 50-min occlusion improved the recovery of GFR, and this protection of GFR was blocked by SPT. Thus, both IPC and exogenous adenosine attenuated ischemic-reperfusion injury of the kidney. However, because three adenosine receptor antagonists failed to abolish the protective effect of IPC, there is no evidence to indicate that activation of adenosine receptors contributes to the IPC effect in the kidney.     

Role of angiotensin in cardioprotective effect of ischemic preconditioning

This study was designed to investigate the role of angiotensin (Ang II) in the cardioprotective effect of ischemic preconditioning. Isolated perfused rat heart was subjected to global ischemia for 30 min followed by reperfusion for 120 min. Coronary effluent was analyzed for lactate dehydrogenase (LDH) and creatine kinase (CK) release to assess the degree of cardiac injury. Myocardial infarct size was estimated macroscopically by using triphenyl tetrazolium chloride (TTC) staining. Four episodes of ischemic/Ang II preconditioning markedly reduced LDH and CK release in the coronary effluent and decreased myocardial infarct size. The cardioprotective effect of Ang II preconditioning was abolished by CV 11974, AT1-receptor antagonist, whereas no such effect was noted with CV 11974 in ischemic preconditioning. PD 123319, AT2-receptor antagonist, produced no marked effect on Ang II preconditioning and ischemic preconditioning induced reduction in myocardial injury. On the basis of these results, it may be concluded that activation of AT1 receptors may be involved in angiotensin-induced pharmacologic preconditioning. But it may not be involved in the cardioprotective effect of ischemic preconditioning in isolated rat heart.     

Low concentrations of paraquat induces early activation of extracellular signal-regulated kinase 1/2, protein kinase B, and c-Jun N-terminal kinase 1/2 pathways: role of c-Jun N-terminal kinase in paraquat-induced cell death.

Paraquat is a herbicide with a potential risk to induce parkinsonism due to its demonstrated neurotoxicity and its strong structural similarity to 1-methyl-4-phenylpyridinium (MPP(+)), a well-known neurotoxin which causes a clinical syndrome similar to Parkinson's disease (PD). However, at present very little is known about the signaling pathways activated by paraquat in any cell system. In this study, we have investigated the effect of paraquat on extracellular signal-regulated kinases 1 and 2 (ERK1/2), c-Jun N-terminal kinase (JNK), and protein kinase B (PKB) activation in E18 cells. Low concentrations of paraquat stimulated very early increases in ERK1/2, JNK1/2, and PKB phosphorylation. The phosphatidylinositol 3-kinase (PI-3K) inhibitors wortmannin and LY 294002 (2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one) inhibited early paraquat-induced increases in PKB phosphorylation. Furthermore, early paraquat-mediated increases in ERK1/2 activation were sensitive to the mitogen-activated protein kinase kinase 1 (MEK1) inhibitor PD 98059 (2'-amino-3'-methoxyflavone), whereas JNK1/2 responses were blocked by the JNK1/2 inhibitor SP 600125 (anthra[1-9-cd]pyrazol-6(2H)-one). Pretreatment with wortmannin, LY 294002, or PD 98059 had no effect on paraquat cell death in E18 cells. In contrast, SP 600125 significantly decreased paraquat-induced cell death in E18 cells. In conclusion, we have shown that low concentrations of paraquat stimulate robust very early increases in ERK1/2, JNK1/2, and PKB phosphorylation in E18 cells. Furthermore, the data presented clearly suggest that inhibition of the JNK1/2 pathway protects E18 cells from paraquat-induced cell death and support the fact that inhibition of early activation of JNK1/2 can constitute a potential strategy in PD treatment.