Raf激酶抑制蛋白与妇科肿瘤间的潜在联系

Raf激酶抑制蛋白(RKIP)是从牛脑中纯化的一种小胞质蛋白,属于磷脂酰乙醇胺结合蛋白家族,具有多重分子与细胞功能。RKIP调节促分裂原活化/细胞外信号调节激酶激酶/细胞外信号调节激酶、G蛋白偶联受体、核因子κB、促分裂原活化蛋白激酶等多个信号转导通路,其减少或缺失可引起细胞功能异常、染色体变异等,进而导致机体的疾病状态,甚至恶性肿瘤的发生。RKIP的多重信号转导途径表明RKIP可能在多种疾病的生物进程,尤其是妇科肿瘤的调节过程中起到关键作用。     

硫化氢对淀粉样前体蛋白代谢途径的影响

目的:观察硫化氢(H2S)对PC12细胞淀粉样前体蛋白(APP)代谢途径的影响,探讨可能的细胞信号机制.方法:用不同浓度硫氢化钠(NaHS,50、100和200 μmol·L-1)作用PC12细胞1和18 h,Western blotting法检测APP、C99、C83、磷脂酰肌醇-3激酶/丝氨酸苏氨酸蛋白激酶(PI3...     

血管紧张素Ⅱ2型受体活化促进缺氧/复氧损伤PC12细胞的生长

目的 探讨血管紧张素Ⅱ2型受体(AT2R)活化对缺氧/复氧(H/R)损伤PC12细胞生长的影响。方法PC12细胞是大鼠肾上腺嗜铬细胞瘤细胞株,具有神经内分泌细胞的一般特征。将PC12细胞用连二亚硫酸钠(Na₂S₂O₄)处理后复制H/R损伤的神经细胞模型;H/R损伤PC12细胞分别予以AT2R拮抗剂(PD123319)、AT2R激动剂(CGP42112)进行处理,采用MTT法观察细胞存活率的变化;以逆转录—聚合酶链式反应(RT-PCR)检测Bax、Bcl-2 mRNA表达的变化。结果PC12细胞经40mmol/LNa₂S₂O₄处理1 h后,MTT法检测的细胞存活率约为55~60%,提示复制H/R损伤模型成功;H/R损伤PC12细胞经CGP42112处理后,细胞存活率显著增高,而Bax mRNA 表达下调,Bcl-2 mRNA 表达上调;而PD123319处理后,细胞存活率显著下降, Bax mRNA 表达上调,Bcl-2 mRNA 表达则下调。结论AT2R活化可改善H/R损伤的PC12细胞的生长,其机理可能与其上调Bcl-2/Bax的比值有关。     

基于POMC/AgRP神经元探讨瘦素调节食欲的作用机制

瘦素与瘦素受体结合后通过多种信号转导途径作用于阿片-促黑素细胞皮质素原/刺鼠相关蛋白神经元,从而发挥食欲调节的作用,进而预防肥胖等多种代谢性疾病的发生。目前发现的瘦素信号转导途径有酪氨酸激酶2/信号转导及转录激活因子3信号转导途径、促分裂原活化的蛋白激酶/胞外信号调节激酶1/2信号转导途径及胰岛素受体底物/磷脂酰肌醇-3-激酶(PI3K)信号转导途径三种。其中,PI3K通过蛋白激酶B/叉头状转录因子O1、离子通道及磷酸二酯酶3B/环腺苷酸三种子通路发挥调节食欲的作用,这些信号转导途径纷繁复杂,涉及多种生理病理反应。此外,各个信号途径中亦存在负反馈调节因子,其可有效地抑制信号途径的过表达,共同为机体的稳定发挥作用。     

外源性硫化氢对嗜铬细胞瘤细胞β位淀粉样前体蛋白裂解酶1表达的影响

 目的观察外源性硫化氢（H2S）对嗜铬细胞瘤细胞（PC12）茁位淀粉样前体蛋白裂解酶1（BACE1）表达的影响,并探讨可
能涉及的细胞信号机制。方法用不同浓度的硫氢化钠（NaHS）处理体外培养的PC12细胞,利用RT-PCR和Western blot法检
测细胞内BACE1mRNA及蛋白表达;继以LY294002 和PD98059 分别阻断磷脂酰肌醇3-激酶/丝氨酸苏氨酸蛋白激酶（PI3-K/
Akt）及丝裂酶原活化蛋白激酶/细胞外信号调节激酶1/2（MAPK/ERK1/2）通路,Western blot 法检测其对NaHS 诱导的通路下游
蛋白Akt1 和ERK1/2 磷酸化的影响及其对BACE1 蛋白表达变化的调节;ELISA法检测细胞培养液中A茁42 水平的变化。结果
NaHS 在实验浓度范围内呈剂量依赖性下调BACE1mRNA 及蛋白表达,200 μmol/L 时最明显,各NaHS 组与对照组相比,差异
均有统计学意义（ P<0.05）;LY294002 抑制NaHS 诱导的Akt1蛋白磷酸化,削弱NaHS 对BACE1 蛋白的下调作用,其表达在
LY294002 预处理组与NaHS 200 μmol/L组相比,差异具有统计学意义（ P<0.05）;而PD98059 虽能抑制NaHS 导致的ERK1/2
蛋白磷酸化,但对其调节BACE1 蛋白表达无影响,PD98059 预处理组与NaHS 200 μmol/L 组相比,差异无统计学意义（ 跃
0.05）;不同处理条件下的A茁42 表达与BACE1 变化趋势基本一致。结论外源性H2S 下调PC12 细胞BACE1 表达,其机制可
能与PI3-K/Akt 信号通路的激活有关,而与MAPK/ERK1/2 通路无关。     

PI3K抑制剂抗肿瘤研究进展

正磷脂酰肌醇-3-激酶(phosphoinositide 3-kinase,PI3K)是一种胞内磷脂酰肌醇激酶,属于细胞内重要的信号转导分子,参与调节细胞的增殖、凋亡与分化等生理过程。研究~([1])发现,PI3K依赖性信号通路在肿瘤发生中的主要特征和关键作用。PI3K介导的信号转导通路控制着众多在肿瘤发生发展中至关重要的细胞生物学过程,通路中的主要组件或上游调控因子的遗传学和表观遗传学的突变导致PI3K     

连接蛋白Lnk的研究进展

Lnk是新近发现的一种连接蛋白，在蛋白酪氨酸激酶（Jak）信号转导子和转录激活子（STAT）、Ras蛋白／丝裂原活化蛋白激酶（MAPK）、磷脂酰肌醇3激酶（PBK）等信号转导途径中发挥负性调节作用。其功能涉及到造血细胞的分化、内皮细胞激活、细胞骨架调控。作者对其结构特征、信号转导调节机制及生物学功能作一综述。     

PDGF-BB/PDGFR信号通路与糖尿病视网膜病变相关性研究进展

糖尿病视网膜病变(DR)是临床常见的致盲性眼病之一,其病理机制主要包括周细胞的选择性丢失与新生血管的形成等,但具体分子学机制目前尚未完全阐明.其中血小板衍生生长因子-BB(PDGF-BB)/血小板衍生生长因子受体(PDGFR)信号通路可通过活化细胞质中的胞外信号调节激酶、磷脂酶Cγ、磷脂酰肌醇-3-激酶等分子途径调节细...     

The effects of paeoniflorin monomer of a Chinese herb on cardiac ion channels

Background  Because of the potential proarrhythmic effect of current antiarrhythmic drugs, it is still desirable to find safer antiarrhythmic drugs worldwide. Paeoniflorin is one of the Chinese herb monomers that have different effects on many ion channels. The present study aimed to determine the effects of paeoniflorin on cardiac ion channels.

Methods  Whole-cell patch-clamp technique was used to record ion channel currents. L-type calcium current (I_Ca-L), inward rectifier potassium current (I_K1), and transient outward potassium current (I_to1) were studied in rat ventricular myocytes and sodium current (I_Na), slow delayed rectifier current (I_Ks), and HERG current (I_Kr) were investigated in transfected human embryonic kidney 293 cells.

Results  One hundred μmol/L paeoniflorin reduced the peak I_Ca-L by 40.29% at the test potential of +10 mV (from (–9.78±0.52) pA/pF to (–5.84±0.89) pA/pF, n=5, P=0.028). The steady-state activation curve was shifted to more positive potential in the presence of the drug. The half activation potentials were (–11.22±0.27) mV vs. (–5.95±0.84) mV (n=5, P=0.007), respectively. However, the steady-state inactivation and the time course of recovery from inactivation were not changed. One hundred μmol/L paeoniflorin completely inhibited the peak I_Na and the effect was reversible. Moreover, paeoniflorin inhibited the I_K1 by 30.13% at the test potential of –100 mV (from (–25.26±8.21) pA/pF to (–17.65±6.52) pA/pF, n=6, P=0.015) without effects on the reversal potential and the rectification property. By contrast, 100 μmol/L paeoniflorin had no effects on I_to1, I_Ks or I_Kr channels.

Conclusions  The study demonstrated that paeoniflorin blocked I_Ca-L, I_Na, and I_K1 without affecting I_to1, I_Ks, or I_Kr. The multi-channel block effect may account for its antiarrhythmic effects with less proarrhythmic potential.

     

视黄醇结合蛋白4与2型糖尿病胰岛素抵抗的相关性研究进展

视黄醇结合蛋白4(RBP4)是一种脂肪细胞因子,与2型糖尿病胰岛素抵抗以及糖代谢和脂代谢障碍均密切相关。RBP4通过c-Jun氨基端激酶(JNK)、IκB激酶(IKK)、胞外信号调节激酶(ERK)1/2及JAK激酶(JAK)2-信号转导和转录激活因子STAT5等信号转导途径干扰胰岛素受体底物磷酸化,从而抑制由胰岛素介导磷脂酰肌醇3-激酶(PI3K)/丝苏氨酸蛋白激酶(Akt)与Ras-丝裂原活化蛋白激酶(Ras-MAPK)调节的糖代谢和脂代谢过程,导致胰岛素抵抗,引起2型糖尿病的发生。     

Sevoflurane postconditioning alleviates action potential duration shortening and L-type calcium current suppression induced by ischemia/reperfusion injury in rat epicardial myocytes

Background  It has been proved that sevoflurane postconditioning (SpostC) could protect the heart against myocardial ischemia/reperfusion injury, however, there has been few research focused on the electrophysiological effects of SpostC. The objective of the study was to investigate the effects of SpostC on action potential duration (APD) and L-type calcium current (I_{Ca, L}) in isolated cardiomyocytes.

Methods  Langendorff perfused SD rat hearts were randomly assigned to one of the time control (TC), ischemia/reperfusion (I/R, 25 minutes of ischemia followed by 30 minutes of reperfusion), and SpostC (postconditioned with 3% sevoflurane) groups. At the end of reperfusion, epicardial myocytes were dissociated enzymatically for patch clamp studies.

Results  Sevoflurane directly prolonged APD and decreased peak I_{Ca, L} densities in epicardial myocytes of the TC group (P <0.05). I/R injury shortened APD and decreased peak I_{Ca, L} densities in epicardial myocytes of the I/R group (P <0.05). SpostC prolonged APD and increased peak I_{Ca, L} densities in epicardial myocytes exposed to I/R injury (P <0.05). SpostC decreased intracellular reactive oxygen species (ROS) levels, reduced the incidence of ventricular tachycardia and ventricular fibrillation, and decreased reperfusion arrhythmia scores compared with the I/R group (all P <0.05).

Conclusions  SpostC attenuates APD shortening and I_{Ca, L} suppression induced by I/R injury. The regulation of APD and I_{Ca, L} by SpostC might be related with intracellular ROS modulation, which contributes to the alleviation of reperfusion ventricular arrhythmia.

     

3, 5, 4'-三甲基白藜芦醇对豚鼠心室肌细胞钠电流和钾电流的影响

目的 研究3, 5, 4''-三甲基白藜芦醇(trans-resveratrol derivative 3,5,4''-trimethoxystilbene，TMS)对豚鼠心室肌细胞钠电流(I_Na)和钾电流(I_K1)的直接作用，探讨其心肌保护作用。方法 用全细胞膜片钳技术记录TMS对单个心室肌细胞I_Na和I_K1的作用。结果 TMS(10 μmol·L^-1)可快速抑制豚鼠心室肌细胞I_Na，用药后3 min左右即开始起效，10 min时抑制率为(36.8±5.6)％(P<0.005)，洗脱后可完全恢复；1，3 μmol·L^-1 TMS未影响I_Na大小。TMS不改变I_Na的最大激活电压，也不影响I_K1的大小。10 μmol·L^-1使半数最大失活电压(V_1/2)由(-87.0±3.3)mV变化到(-96.7±3.5)mV (P<0.001)，使失活曲线斜率(S)由(4.9±0.3)mV 变化到(5.4±0.3)mV (P<0.01)；使半数最大激活电压(V_1/2) (-38.9±1.4)mV 变化到(-47.3±1.3)mV (P<0.001)，未改变激活S。结论 TMS可直接作用于豚鼠心室肌细胞，快速抑制I_Na，且此作用快速、可逆。     

前列环素信号通路的研究进展

前列环素（PGI₂）是前列腺素家族的重要成员,由花生四烯酸在血管内皮细胞环氧合酶和前列环素合酶的作用下生成。PGI₂与细胞膜上组织特异性的G蛋白偶联受体前列环素受体相结合,激活腺苷酸环化酶,增加cAMP的含量,激活蛋白激酶A,从而发挥舒张血管、抑制血小板聚集、抑制血管平滑肌细胞增殖和迁移等作用。高浓度时,PGI₂可与一种核受体过氧化物酶体增殖物激活受体相互作用,调节心血管系统多种生理功能,如血管新生等。本文就PGI₂合成和信号转导通路的研究进展进行综述。     

PI3K/Akt/mTOR信号通路在常见妇科疾病中的研究进展

磷脂酰肌醇3激酶/蛋白激酶B（PI3K-Akt）信号通路是细胞内重要信号转导通路,也是机体内一条重要的信号通路,在细胞生长、增殖、分化和蛋白合成等过程中起重要作用。子宫内膜癌、子宫内膜异位症、多囊卵巢综合征、卵巢癌等属于常见的女性生殖系统疾病,与机体内磷脂酰肌醇3激酶/蛋白激酶B/哺乳动物雷帕霉素靶蛋白（PI3K/Akt/mTOR）信号通路和雌激素水平异常存在一定的相关性。本文就PI3K/Akt/mTOR信号通路在常见妇科疾病中的作用作一综述,以期为常见妇科疾病靶向治疗提供新思路。

     

邻苯二甲酸二(2-乙基已基)酯对人神经母细胞瘤细胞增殖的影响

目的 探讨环境内分泌干扰物邻苯二甲酸二（2-乙基已基）酯（di-2-ethylhexyl phthalate,DEHP）对人神经母细胞瘤细胞增殖的影响及机制。方法 体外培养人神经母细胞瘤SK-N-SH细胞,分为5组：不加干预药物（对照组）、加17β-雌二醇（17β-estradiol,E₂组）、加DEHP（DEHP组）、同时加E₂和磷脂酰肌醇3-激酶（phosphatidylinositol-3-kinases,PI3K）抑制剂LY294002（E₂ + LY294002组）、同时加DEHP和LY294002（DEHP + LY294002组）。检测各组细胞0、2、5 d时光吸收度值（absorbance value,AV）,5 d时DNA增殖指数（proliferation index,PI）,凋亡指数（apoptotic index,AI）、Capase-3蛋白、蛋白质丝氨酸苏氨酸激酶（protein-serine-threonine kinase,Akt）以及磷酸化Akt（phosphor-AktSer473,p-AktSer473）蛋白表达。结果 E₂和DEHP组2、5 d时AV值及5 d时PI值均较对照组明显增高（P<0.01）,而E₂ + LY294002和DEHP + LY294002组则较E₂和DEHP组明显降低（P<0.01）,各组AI及Caspase-3蛋白表达无明显变化。5 d时p-AktSer473蛋白表达,E₂和DEHP组较对照组增加（P<0.01）,而E₂ + LY294002和DEHP + LY294002组则较E₂和DEHP组明显减少（P<0.01）,各组Akt蛋白表达无明显变化。结论 DEHP可促进人神经母细胞瘤SK-N-SH细胞体外增殖,作用与雌激素相仿。该促增殖效应可能通过PI3K/Akt信号通路起作用,与细胞凋亡途径无关。     

5-脂氧合酶与细胞增殖及凋亡

5-脂氧合酶是5-脂氧合酶代谢通路中催化花生四烯酸转化为白三烯和氢氧化物的关键酶,在恶性肿瘤和多种病变细胞中高表达。它可以通过分裂原活化蛋白激酶激酶/细胞外信号调节激酶以及磷酯酰肌醇3激酶/蛋白激酶B等信号转导途径促进肿瘤细胞增殖,抑制肿瘤细胞凋亡。除此之外,5-脂氧合酶还可通过多种方式调控呼吸系统、消化系统以及循环系统等病变细胞的增殖与凋亡。     

Interaction of signal transduction between angiotensin AT1 and AT2 receptor subtypes in rat senescent heart

Background  Angiotensin II (Ang II) acting at angiotensin AT₁ receptor (AT₁R) has well documented effects on cardiovascular structure such as the promotion of cardiovascular hypertrophy and fibrosis, which are believed to be opposed by angiotensin AT₂ receptor (AT₂R) stimulation. The expressions of AT₁R and AT₂R are up-regulated in senescent hearts. The purpose of this study was to investigate the interaction of signal transduction between AT₁R and AT₂R, and to detect whether there is any difference in the interaction in rat hearts of different age.
Methods  In 3.5-, 12-, 18- and 24-month-old rats, the heart cell membrane activities of protein kinase C (PKC) and tyrosine kinase were measured when AT₁R and AT₂R were both activated by Ang II or just the AT₁R was activated by Ang II and PD123319. The activities of cytosolic phospholipase A₂ (cPLA₂) and the levels of cGMP were investigated when AT₁R and AT₂R were both activated by Ang II or just the AT₂R was activated by Ang II and losartan. 
Results  When AT₁R and AT₂R were both activated compared to when the AT₁R was activated, the activities of PKC were not different in hearts from 3.5- and 12-month-old rats, but decreased significantly in 18- and 24-month-old rats; the activities of tyrosine kinase were not different in 3.5-month-old rats but decreased significantly in 12-, 18- and 24-month-old rats. The activities of cPLA₂ were all decreased significantly in rats of different age when AT₁R and AT₂R were both activated compared to when the AT₂R was activated. Treatment with Ang II alone compared to Ang II and losartan decreased the levels of cGMP (fmol/mg) in rats of different age (102.7±12.7 versus 86.0±8.0 in 3.5-month-old rats, P<0.05; 81.0±9.4 versus 70.0±6.3 in 12-month-old rats, P<0.05; 69.8±5.6 versus 54.2±5.3 in 18-month-old rats, P<0.01; 57.7±8.0 versus 39.0±3.0 in 24-month-old rats, P<0.01).
Conclusions  The activation of AT₁R inhibited the signal transduction of AT₂R during the aging variation, and the activation of AT₂R inhibited the signal transduction of AT₁R in rat heart of different age.

     

MAPK、PI3K途径在蛇毒神经生长因子诱导PC12细胞分化的作用

目的 研究丝裂原激活蛋白激酶(MAPK)和磷脂酰肌醇3-激酶(PI3K)/Akt途径在蛇毒神经生长因子(NGF)诱导PC12细胞分化中的作用.方法 应用蛋白免疫印迹法分析p44/p42MAPK和Akt的磷酸化水平,并利用MAPK抑制剂PD98059和PI3K抑制剂LY294002,观察其对NGF诱导的PC12细胞形态学改变的影响.结果 眼镜蛇毒NGF在10ng/mL即可诱导PC12细胞长出突起,100,1000ng/mL作用明显,呈剂量效应关系;NGF能有效刺激p44/p42MAPK、Akt的磷酸化;分别用特异抑制剂PD98059抑制MAPK活性,LY294002抑制PI3K活性后,NGF诱导的细胞分化均受抑制.结论 蛇毒神经生长因子诱导PC12细胞的分化作用与p44/p42MAPK和PI3K/Akt途径相关.     

p38MAPK抑制剂SB203580减轻罗哌卡因对PC12细胞的毒性

目的：探讨p38MAPK抑制剂SB203580对罗哌卡因诱发大鼠肾上腺嗜铬细胞瘤细胞(PC12)的毒性的影响及 其机制。方法：将PC12细胞分为对照组(N组)、罗哌卡因组(R组,15 mmol/L盐酸罗哌卡因)、罗哌卡因+SB203580组 (R+S组,15 mmol/L盐酸罗哌卡因+10 μmol/L SB203580)。培养48 h后行3组细胞计数并采用MTT法检测细胞存活率; 采用蛋白质印迹法检测各组磷酸化p38(p-p38)、活化的caspase-3的表达以及细胞质中细胞色素C(cytochrome C,Cyt C) 的含量。结果：与N组比较,R组和R+S组的PC12细胞数目及细胞存活率均显著减少(均P<0.05);且R+S组的PC12细胞 数目和存活率较R组显著上升(均P<0.05)。与N组比较,R组和R+S组p-p38,活化的caspase-3的表达以及细胞质中Cyt C 的含量显著增加(均P<0.05);与R组比较,R+S组p-p38,活化的caspase-3的表达以及细胞质中Cyt C的含量明显减少(均 P<0.05)。结论：抑制p38磷酸化可减轻罗哌卡因对PC12细胞的毒性作用,其机制可能与减少释放入细胞质的Cyt C和 caspase-3的活化有关。     

Effect of basic fibroblast growth factor and transforming growth factor β1 on the healing of reconstructed dura by carbon dioxide laser soldering in minipigs

Background  Carbon dioxide (CO₂) laser soldering is an alternative technique for tissue bonding. Basic fibroblast growth factor (bFGF) and transforming growth factor β₁ (TGFβ₁) are two key factors for wound healing. This study was performed to demonstrate the efficacy of CO₂ laser soldering for dural reconstruction and the effect of bFGF and TGFβ₁ on healing.

Methods  In Part I, 10 minipigs were randomized into two equal groups. Dural defects were reconstructed by conventional fibrin glue bonding (group I_a) or CO₂ laser soldering (group I_b). The reconstructed dura was subjected to burst pressure (BP) measurement and immunohistochemical staining after 1 week. In Part II, 36 minipigs were randomized into three equal groups. Dural reconstruction was achieved by CO₂ laser soldering. Exogenous bFGF (group II_b) or TGFβ₁ (group II_c) was administered while group II_a served as a control group. The specimens were subjected to BP measurement after 1, 2, 3, and 4 weeks, respectively.

Results  In Part I, the dura specimens displayed positive staining of only bFGF in group I_a and of both bFGF and TGFβ₁ in group I_b. Group I_b showed higher BP than group I_a ((98.00±21.41) mmHg vs. (70.80±15.09) mmHg, respectively; P <0.05). In Part II, BP of group II_c was significantly higher than that of group II_a (P <0.01). The BP of group II_a trended toward stabilization after 3 weeks of growth, while that of groups II_b and II_c trended toward stabilization after 2 weeks of growth.

Conclusions  CO₂ laser soldering is a reliable technique for dural reconstruction. The superior healing of dural reconstruction by CO₂ laser soldering may be related to higher expression of bFGF and TGFβ₁, and CO₂ lasers may stimulate their secretion. Exogenous bFGF or TGFβ₁ may improve healing by shortening the wound healing time, and exogenous TGFβ₁ may improve the tensile strength.