软脂酸通过丝裂原活化蛋白激酶通路促进血管内皮细胞凋亡

目的探讨软脂酸(PA)诱导的血管内皮细胞凋亡中丝裂原活化蛋白激酶(MAPK)通路的作用。方法将人脐静脉内皮细胞(HUVEC)分对照组、PA组、MAPK通路干预组[分别先用p38抑制剂SB203580、氨基末端激酶(JNK)抑制剂PD98059、细胞外信号调节激酶(ERK)抑制剂SP600125干预]再分为PA+SB组、PA+PD组、PA+SP组。流式细胞仪检测细胞凋亡率;Western blot法检测caspase-3、磷酸化p38、JNK和ERK1/2表达水平;分光光度法检测caspase-3的活性。结果与对照组比较,PA组、PA+SB组、PA+PD组、PA+SP组HUVEC凋亡及caspase-3表达和活性明显增加,PA组磷酸化p38MAPK表达明显增加(P<0.05)。与PA组比较,PA+SB组HUVEC细胞凋亡率、caspase-3表达和活性明显降低(P<0.05);而PA+PD组和PA+SP组HUVEC凋亡率、caspase-3表达和活性无明显变化(P>0.05)。结论 PA通过p38MAPK通路促进内皮细胞凋亡。     

乐卡地平对老年大鼠血管平滑肌细胞增殖和凋亡的影响

目的探讨大鼠血管平滑肌细胞(VSMCs)发生衰老过程中,乐卡地平对细胞增殖和凋亡的影响和作用机制。方法取原代培养的4月龄和24月龄Wistar大鼠VSMCs分别为青年组、老年组,青年和老年大鼠加乐卡地平10μmol/L处理24 h分为青年实验组和老年实验组。采用免疫荧光染色、Western blot法、流式细胞分析仪和Real-time共聚焦等技术检测各组细胞核内p21蛋白结构含量的变化、细胞的增殖及凋亡指数和凋亡率。结果与青年组比较,青年实验组大鼠VSMCs分裂指数明显下降,相差13倍(P<0.05)。与青年组大鼠比较,乐卡地平对老年组大鼠的细胞内钙的抑制作用更强。与老年组比较,老年实验组大鼠细胞分裂指数和凋亡指数降低,差异有统计学意义[(2.08±0.22)%vs(0.7±0.06)%,P<0.05],凋亡率明显下降,差异有统计学意义[(16.1±2.04)%vs(2.3±0.88)%,P<0.01]。与青年组和老年组比较,老年实验组大鼠细胞核内p21蛋白随乐卡地平剂量增加而增强,蛋白结构发生变化,增殖性核抗原表达减少。结论乐卡地平通过改变p21蛋白的结构和含量表达,从而抑制增殖性核抗原表达,抑制VSMCs的增殖,降低老年大鼠VSMCs凋亡,减缓衰老。     

盐酸法舒地尔后适应对大鼠心肌缺血再灌注损伤的保护作用

目的通过主动脉根部模拟冠状动脉内给药,观察盐酸法舒地尔后适应对大鼠急性心肌缺血再灌注损伤的保护作用。方法选择SD大鼠48只,随机分为假手术组、缺血再灌注组、缺血后适应组、法舒地尔组,每组12只。各组于再灌注3 h后处死大鼠,分别测定心功能参数、血浆心肌酶、心肌梗死范围和心肌细胞凋亡指数。结果与假手术组比较,缺血再灌注组、缺血后适应组和法舒地尔组血浆心肌酶含量明显升高,差异有统计学意义(P<0.01)。与缺血再灌注组比较,法舒地尔组心功能参数明显改善,血浆心肌酶含量、心肌梗死范围、心肌细胞凋亡指数明显下降,差异有统计学意义(P<0.01)。结论盐酸法舒地尔可以模拟缺血后适应效应,减轻心肌缺血再灌注损伤,减少缺血心肌细胞凋亡,缩小心肌梗死范围。     

Activation of c-Jun N-terminal kinase in non-cancerous liver tissue predicts a high risk of recurrence after hepatic resection for hepatocellular carcinoma

Aim: Hepatocellular carcinoma (HCC) ranks as the third leading cause of cancer deaths worldwide. Hepatic resection is the mainstay of curative treatment for early stage HCC. Although c‐Jun N‐terminal kinase (JNK) activation contributes to hepatocyte proliferation and HCC development in mice, the extent of involvement of JNK in human HCC development is unknown. The aim of this study is to assess the predictive value of JNK for postoperative recurrence in HCC. Methods: From April 2005 to March 2008, 159 patients underwent curative resection for HCC. From the 159 patients, 20 patients each matched for age, gender and etiology were registered as three groups: (i) without recurrence (no recurrence group), (ii) with recurrence within one year after surgery (early recurrence group), and (iii) with recurrence at one year or more after surgery (late recurrence group) (a cross‐sectional control study). We investigated factors contributing to postoperative early and late phase recurrence. Results: Multivariate analysis using a Logistic regression model showed that JNK activity in non‐cancerous liver tissue was correlated with postoperative late recurrence. (P = 0.02, odds ratio; 5.79, 95% confidence interval [CI]; 1.33–25.36). Conclusions: JNK activity in non‐cancerous liver tissue is considered as a reliable predictive biomarker for post‐operative recurrence in HCC.     

Randomized phase II study of sunitinib versus standard of care for patients with previously treated advanced triple-negative breast cancer

PurposeThis randomized, open-label phase II study compared the efficacy of sunitinib monotherapy with that of single-agent standard-of-care (SOC) chemotherapy in patients with previously treated advanced triple-negative breast cancer (TNBC).MethodsPatients with advanced TNBC, relapsed after anthracycline- and taxane-based chemotherapy, were randomized to receive either sunitinib (37.5 mg/day) or the investigator's choice of SOC therapy. Progression-free survival was the primary endpoint.ResultsMedian progression-free survival was 2.0 months with sunitinib and 2.7 months with SOC chemotherapy (one-sided P = 0.888). Median overall survival was not prolonged with sunitinib (9.4 months) compared with SOC chemotherapy (10.5 months; one-sided P = 0.839). The objective response rate was 3% with sunitinib and 7% with SOC chemotherapy (one-sided P = 0.962).ConclusionsSunitinib monotherapy did not improve efficacy compared with SOC chemotherapy in patients with previously treated advanced TNBC, for which identification of effective treatments and therapeutic targets remains an urgent need.Trial registrationNCT00246571.     

Caveolin-1下调细胞外调节蛋白激酶1/2抑制血管吻合口再狭窄

目的 探讨Caveolin-1对新西兰兔颈总动脉血管吻合口再狭窄的作用,以及与细胞外调节蛋白激酶(extracellular regulated protein kinases,ERK)的关系.方法 40只新西兰兔,随机分为正常对照组、手术组、空转染组和Caveolin-1转染组.行左侧颈总动脉血管端端吻合,并局部转染Caveolin-1质粒(转染组)或空质粒(空转染组).于术后第7天各组中分别取5只新西兰兔血管标本,用于Western blot和逆转录-聚合酶链反应(RT-PCR)检测蛋白和mRNA的表达;其余新西兰兔于术后28 d处死取颈总动脉,通过HE染色观察内膜增生情况,用Image-Pro Plus6.0软件测量内膜与中膜面积比值(IA/MA).结果 血管HE染色后测量内膜与中膜面积比值:Caveolin-1转染组的血管内膜/中膜面积比值较手术组降低约50％;与手术组比较,转染组Caveolin-1的mRNA和蛋白的表达明显升高,差异有统计学意义(t=36.59,P＜0.01);而在高表达Caveolin-1的血管吻合口上,ERK1/2的mRNA的表达以及蛋白质的活性都显著低于手术组(t值分别为:32.64和7.28,两者均P＜0.01).结论 Caveolin-1抑制吻合口再狭窄的作用可能与调节ERK1/2的活化有关.     

MK2 plays an important role for the increased vascular permeability that follows thermal injury

We previously reported Rho kinase is involved in vessel hyper-permeability caused by burns. Here we further explore the Rho kinase downstream signaling, it is found that its specific inhibitor Y27632 significantly diminishes the activation of JNK and p38 MAPKs but not ERK that induced by serum from burned rats (burn-serum). JNK activation was found involved in the expression of HUVEC adhesion molecules following thermal injury, although not in the process of stress fiber formation. Inhibition of various MAPKs by specific inhibitors showed that SB203580 (inhibitor of p38), but neither SP600125 (inhibitor of JNK) nor PD98059 (inhibitor of ERK), abolish activation of the p38 downstream kinase MK2. Demonstration of stress fibers by fluorescent-labeled phalloidin showed that inhibition of MK2, either by its specific inhibitor or by dominant negative adeno-viral-carried constructs, significantly reduced burn-serum-induced HUVEC stress-fiber formation, while inhibition of another downstream p38 MAPK kinase, PRAK, had no such effects. Transfection of dominant negative adeno-viral MK2 (Ad-MK2(A)) significantly inhibited thermal injury-induced blood vessel hyper-permeability in rats and, moreover, prolonged the survival of burned rats beyond 72 h following thermal injury. One of the mechanisms behind these phenomena is that Ad-MK2(A) causes a significant depression of burn-serum-induced HSP27-phosphorylation, while the adeno-viral transported dominant negative PRAK (Ad-PRAK(A)) does not block. Although the effect of blockade of MK2 through its adeno-viral approach requires further study and investigation of alternatives to know for sure, we may have found a new pathway behind thermal-injury-induced blood vessel hyper-permeability, namely: Rho kinase > p38 > MK2 > HSP27.     

孕酮预处理对大鼠局灶性脑缺血再灌注损伤的保护作用及机制

目的 探讨孕酮预处理对局灶性脑缺血再灌注损伤(focal cerebral ischemic and reperfusion injury,fCIRI)的作用及机制.方法 在建立大鼠fCIRI模型前96、48、1h分别给予孕酮(8mg/kg)1次性腹腔注射.建立大鼠fCIRI模型,在fCIRI后第3～8天,检查大鼠的空间记忆功能和缺血侧海马CA1区存活神经元数量.检测孕酮预处理后1～96 h的海马细胞外信号调节激酶1/2(ERK1/2)磷酸化水平和活化ERK1/2核转移.结果 造模前48、1h经孕酮预处理的大鼠海马CA1区神经元存活数量(mm-1)较造模后明显增多(164.3±11.0、218.5±9.1与142.7±12.1,F=29.45,P＜0.01);造模前48、1h经孕酮预处理的大鼠能明显缩短脑缺血导致的水迷宫逃避潜伏期(s)延长(32.4±14.3、10.3±11.1与19.2±9.6;F=35.84,P＜0.01).海马CA1区ERK1/2磷酸化水平在孕酮给药后的12 ～48 h明显增强,96 h恢复基线.核内ERK1/2磷酸化水平在孕酮给药后2h增加,并持续到48 h.孕酮增加胞质ERK1/2及胞核内ERK1/2磷酸化的水平能被RU486阻断.结论 孕酮预处理对缺血引起的海马CA1区神经元死亡有保护作用,并能改善空间记忆功能;孕酮预处理的神经保护作用有48 h以上的有效时间窗;在孕酮的神经保护作用依赖于孕酮受体介导的ERK1/2信号通路.     

Distinct set of kinases induced after retrieval of spatial memory discriminate memory modulation processes in the mouse hippocampus

Protein phosphorylation and dephosphorylation events play a key role in memory formation and various protein kinases and phosphatases have been firmly associated with memory performance. Here, we determined expression changes of protein kinases and phosphatases following retrieval of spatial memory in CD1 mice in a Morris Water Maze task, using antibody microarrays and confirmatory Western blot. Comparing changes following single and consecutive retrieval, we identified stably and differentially expressed kinases, some of which have never been implicated before in memory functions. On the basis of these findings we define a small signaling network associated with spatial memory retrieval. Moreover, we describe differential regulation and correlation of expression levels with behavioral performance of polo‐like kinase 1. Together with its recently observed genetic association to autism‐spectrum disorders our data suggest a role of this kinase in balancing preservation and flexibility of learned behavior. © 2013 Wiley Periodicals, Inc.