淋巴细胞功能相关抗原-1在冻融PMN介导的VEC损伤中的作用

目的：探讨组织冻结融化造成血管内皮细胞（VEC）损伤的机理。方法：采用密度梯度离心法分离大鼠外周血嗜中性粒细胞（PMN）,速率冷冻仪冷冻PMN后水浴复温建立冻融PMN模型。冻融后4、12和24h,测定PMN表面淋巴细胞功能相关抗原－1（LFA－1）的表达;将冻融PMN与正常VEC共同孵育后测定培养液中乳酸脱氢酶活性及冻融PMN与VEC的粘附。结果：冻融后24h内,冻融PMN表面LFA－1的表面呈时间依赖性增强。（2）冻融PMN与VEC相互作用后,PMN－VEC粘附明显增强、VEC受到明显损伤。（3）抗LFA－1单克隆抗体明显抑制冻融PMN与VEC粘附的增强、明显减轻VEC损伤。结论：冻融可诱发PMN表面LFA－1的表达,进而增强PMN－VEC粘附而导致VEC损伤。     

TNF-α在冻融嗜中性粒细胞介导血管内皮细胞损伤中的作用

目的:探讨肿瘤坏死因子-α(TNF-α)在组织冻融造成的血管内皮细胞(VEC)损伤过程中的作用.方法:以右旋糖酐沉降法分离的大鼠嗜中性粒细胞(PMN)和体外培养的大鼠VEC为实验材料,建立细胞冻融模型.通过测定培养液中LDH活性确定VEC损伤程度,采用活性染料吞噬法检测与VEC粘附的PMN数,以流式细胞技术分析淋巴细胞功能相关抗原-1(LFA-1)表达.结果:TNF-α上调冻融PMN表面LFA-1表达,促进冻融PMN与正常VEC粘附,增强VEC损伤.抗LFA-1Mab部分阻断冻融PMN与正常VEC粘附,减轻VEC损伤.结论:在冻融损伤过程中TNF-α促进PMN表面LFA-1表达,增强PMN-VEC粘附,加重VEC损伤.     

内皮素-1预处理对培养乳鼠心肌细胞低氧损伤的保护作用

实验观察了 0 0 1- 1nmol/L内皮素 1(ET 1)预处理对低氧孵育 ( 3 %O2 5 %CO2 ,12h)的培养乳鼠心肌细胞乳酸脱氢酶 (LDH)释放量、培养液上清超氧化物歧化酶 (SOD)活性以及丙二醛 (MDA)含量的影响。用Fluo 3 /AM负载培养的心肌细胞 ,在激光扫描共聚焦显微镜下监测急性低氧的心肌细胞 [Ca2 +]i 的变化和ET 1预处理对低氧所致 [Ca2 +]i 变化的影响。结果如下 :( 1)心肌细胞低氧孵育 12h后 ,培养液上清LDH活力和MDA含量较常氧对照组明显升高 ,分别为 43 3 3± 1 2 1U/Lvs 19 3 3± 1 0 3U/L和 1 71± 0 0 2nmol/Lvs 0 91± 0 0 3nmol/L (P<0 0 1) ,SOD活性为 16 93± 1 11U/ml明显低于常氧对照组的 3 3 48± 1 15U/ml (P <0 0 1) ;0 0 1- 1nmol/LET 1预处理呈浓度依赖性抑制低氧培养心肌细胞LDH释放 ,减少培养液上清MDA含量、提高SOD活性 (P <0 0 1)。 ( 2 )低氧灌流后 2 9± 1 5s (n =2 3 )心肌细胞自发性钙瞬变完全终止 ,[Ca2 +]i 升高了 10 7± 13 2 % (P <0 0 0 1) ;0 0 1- 1nmol/LET 1能明显加快心肌细胞钙瞬变的频率 (P <0 0 1) ;ET 1预处理后低氧所致钙瞬变终止的时间较单纯低氧组明显推迟 ,[Ca2 +]i过度升高被明显减轻 (P <0 0 1)。上述结果表明 ,0 0 1- 1nmol/LET 1预处理可减轻培     

一氧化氮供体对过氧化氢引起的心肌细胞损伤的保护作用

关于一氧化氮(NO)对心肌细胞是否具有保护作用目前尚存在争议,为探讨NO对过氧化氢(H2O2)引起的心肌细胞损伤是否具有保护作用及其可能的机制,实验将体外培养的新生大鼠心肌细胞分为3组(1)阴性对照组(Normal组);(2)H2O2组H2O2(0.1mmol/L)与心肌细胞共育4h;(3)S-亚硝基-N-乙酰青霉胺(SNAP)+H2O2组NO供体SNAP(0.5mmol/L)处理心肌细胞10min后,加入H2O2与心肌细胞共育4 h.用流式细胞术检测心肌细胞凋亡率,心肌细胞损伤程度以心肌细胞存活率和乳酸脱氢酶(lactate dehydrogenase,LDH)活性来表示,同时检测心肌细胞超氧化物歧化酶(superoxide dismutase,SOD)活性和丙二醛(MDA)含量.通过激光共聚焦显微术检测在不同处理条件下心肌细胞胞内钙的变化.结果表明,正常心肌细胞LDH活性和细胞存活率分别为631.4±75.6 U/L和93.1±6.2%,细胞凋亡率为0;H2O2处理细胞后可使细胞LDH活性显著增高(1580.5±186.7 U/L,P＜0.01),细胞存活率明显下降(58.3±7.6%,P＜0.01),流式细胞仪检测到大量心肌细胞凋亡,凋亡率为26.4±5.7%;SOD活性较正常细胞19.67±0.85 NU/ml显著下降,为14.73±1.68 NU/m(P＜0.01),MDA含量较正常细胞6.95±0.83μmol/L显著增高,为15.35±3.49μmol/L(P＜0.01).SNAP预处理细胞可显著提高心肌细胞存活率(79.7±9.3%,P＜0.01),降低LDH活性和细胞凋亡率(分别为957.8±110.9 U/L和9.1±3.3%,P＜0.01);并提高细胞抗氧化能力,表现为较H2O2处理组的SOD活性增高(21.36±3.11 NU/ml,P＜0.01),MDA含量下降(9.12±1.47 μmol/L,P＜0.01).激光共聚焦显微镜检测结果表明,H2O2可升高细胞内钙,而SNAP则可降低细胞内钙,SNAP预处理细胞后可取消H2O2升高细胞内钙的作用.上述结果提示,NO供体SNAP可对抗H2O2对心肌细胞的损伤,其机制与提高心肌细胞抗氧化损伤能力和对抗H2O2引起的细胞内钙超载有关.     

人类免疫缺陷病毒/丙型肝炎病毒混合感染者免疫细胞和肝生化指标的分析

目的 探讨人类免疫缺陷病毒/丙型肝炎病毒(HIV/HCV)混合感染者的免疫淋巴细胞亚群和肝脏生化指标的特征。方法 检测并分析研究组(40例混合感染HIV/HCV的血友病患者)和对照组(12例单独感染HIV的血友病患者)若干相关实验室指标。结果两组(研究与对照)结果 差异显著的指标分别为:自然杀伤(NK)细胞9.26%±5.98%对12.19%±5.80%,P<0.05;CD4/CD8细胞比值0.39±0.21对0.53±0.24,P<0.05;CD3细胞74.99%±10.33%对68.42%±8.82%,P<0.05;CD8细胞52.28%±12.59%对43.58%±10.99%,P<0.05;丙氨酸氨酶(ALT)(48.59±40.21)U/L对(26.87±27.23)U/L,P<0.01;天冬氨酸转氨酶(AST)(61.66±51.02)U/L对(34.17±30.24)U/L,P<0.001;谷氨酰转肽酶(GGT)(136.50±111.50)U/L对(43.88±36.17)U/L,P<0.001;甘胆酸(CG)(683.41±962.22)μg/L对(250.96±290.81)μg/L,P<0.001;透明质酸(HA)(180.94±196.69)ng/ml对(64.68±32.74)ng/ml,P<0.001;白/球蛋白(A/G)比值1.35±0.24对1.50±0.34,P<0.05。与单独HIV感染者比较,HIV/HCV混合感染者的NK细胞、CD4/CD8细胞比值和A/G比值显著降低,而ALT、AST、GGT、CG和HA的水平显著增加。结论 HIV/HCV混合感染可能加剧患者淋巴细胞亚群的不平衡,加重肝脏损伤和出现肝硬化趋势。     

氯化钠对培养的大鼠主动脉平滑肌细胞的心房钠尿肽受体的调节

培养的卒中型自发性高血压大鼠(SHR_(sp))及其对照 WKY 大鼠主动脉平滑肌细胞(VSMC)上存在心房钠尿肽(ANP)的特异性受体,它们与~(125)I-ANP 的最大结合量(B_(max))是:SHR_(sp)3.65±0.13和 WKY 1.89±0.09 pmol/mg pr(P<0.01);解离平衡常数(Kd)值分别是72.6±10.2和42.0±4.8×10~(-12)mol/L(P<0.01)。 两种细胞内介导舒血管作用的第二信使、环磷酸乌苷(cGMP)的基础浓度无显著差异,对相同剂量 ANP 刺激引起 cGMP 分别增加139(SHRsp)和271(WKY)倍。可见 SHRsp 的 VSMC ANP 受体数量虽比 WKY大鼠增多,但对相同剂量 ANP 引起的 cGMP 增加反应及 ANP 受体的亲和力均显著降低。高盐培养液孵育24h 后,细胞表面 ANP 受体的亲和力改变不明显,但受体数量下调,SHRsp 和 WKY 大鼠分别降至对照的34.8±8.2%和38.6±9.4%,细胞对 ANP 引起的 cGMP增加反应明显降低,且均以 SHR_(sp)较显著。提示后两种变化可能在高盐促进血压升高的机制中起作用。     

王不留行黄酮苷对过氧化氢和高糖诱导损伤的人脐静脉内皮细胞的保护作用

体外培养人脐静脉内皮细胞,乳酸脱氢酶(LDH)试剂盒评价王不留行黄酮苷孵育24 h后的细胞毒性。先给予13.76、6.88、3.44μmol/L的王不留行黄酮苷和维生素C阳性对照组(浓度为100μmol/L)预孵育12 h后,再分别以H2O2和高糖诱导内皮细胞损伤。SRB法测定细胞活力,试剂盒检测乳酸脱氢酶(LDH)、丙二醛(MDA)、超氧化物歧化酶(SOD)含量。与模型组相比,王不留行黄酮苷13.76、6.88、3.44μmol/L组均可改善H2O2和高糖损伤模型的细胞活力,尤以13.76μmol/L作用最为显著(P0.01);并且王不留行黄酮苷13.76μmol/L显著降低H2O2和高糖损伤组培养液中LDH和MDA释放量,增强细胞内SOD活性。     

硒对亚硝酸钠导致的草鱼肝细胞氧化损伤的保护作用

以草鱼(Ctenopharyngodon idella)肝细胞(L8824)为研究对象, 设置对照组、亚硝酸钠暴露实验组、亚硒酸钠孵育实验组和亚硒酸钠孵育后亚硝酸钠暴露实验组, 探讨亚硒酸钠对不同浓度亚硝酸钠诱导L8824细胞氧化损伤及凋亡的保护作用。结果显示, 亚硝酸钠暴露能抑制L8824细胞贴壁, 导致细胞凋亡率增加。亚硝酸钠暴露引致L8824细胞的谷胱甘肽过氧化物酶(GPX)、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性降低; gpx、sod和cat基因表达下调(P<0.05), DNA损伤诱导转录物3(ddit3)和bcl-2相关X蛋白(bax)基因表达上调(P<0.05)。亚硒酸钠(10 μmol/L)孵育L8824对细胞形态和凋亡率无显著影响, 但GPX、SOD和CAT活性上升, gpx、sod、cat、核因子E2相关因子2(Nrf2)和Kelch样环氧氯丙烷相关蛋白-1(keap1)基因表达上调(P<0.05)。亚硒酸钠孵育后亚硝酸钠暴露实验组, 细胞凋亡率、GPX、SOD和CAT活性较对照组无显著变化, 但B淋巴细胞瘤-2(bcl-2)基因表达显著上调(P<0.05)。研究结果表明, 给草鱼肝细胞补充硒在一定程度上能缓解亚硝酸钠暴露导致的抗氧化系统失衡, 抵抗亚硝酸钠暴露带来的氧化应激, 降低细胞凋亡率, 硒的预孵育作用能上调Nrf2/Keap1通路中的关键基因和酶, 表明硒的保护作用可能是通过介导 Nrf2/Keap1信号通路发挥作用。     

欧前胡素通过ERK1/2信号保护心肌细胞低氧性损伤

目的:研究欧前胡素对低氧诱导的大鼠心肌细胞损伤的保护作用和机制。方法:采用CO2-95%和N2-5%的细胞培养箱诱导H9c2大鼠心肌细胞建立心肌细胞低氧损伤模型,采用不同浓度的欧前胡素孵育细胞12、24 h,检测上清液中乳酸脱氢酶(lactate dehydrogenase,LDH)、超氧化物歧化酶(superoxide dismutase,SOD)、丙二醛(malondialdehyde MDA)的含量。采用MTT方法检测细胞的存活率,Annexin V/PI双标记流式细胞术检测细胞凋亡比例,蛋白质印迹法检测检ERK1/2蛋白的表达。结果:低氧处理H9c2心肌细胞12 h后,上清中LDH和MDA的含量分别为(523.28±90.29)U/L和(5.59±0.33)U/L,均明显高于对照组(P0.05),而SOD的含量[(12.23±1.38)U/mg]明显低于对照组(P0.05)。低、高浓度欧前胡素孵育12 h后,细胞存活率分别为(64.51±2.78)%和(73.22±3.56)%,低、高浓度欧前胡素孵育24 h后,细胞存活率分别为(80.21±4.67)%和(87.38±5.41)%,均较与模型组显著升高(P0.05)。高浓度欧前胡素孵育12 h和24 h后凋亡细胞比例分别为(39.67±4.11)%和(49.61±3.39)%,均较模型组显著降低(P0.05),10μmol/L的PD98059阻断ERK1/2信号通路后细胞存活率均较高浓度欧前胡素组显著降低,凋亡细胞比例较高浓度欧前胡素明显升高(P0.05)。高浓度欧前胡素孵育12 h和24 h后,ERK1/2蛋白相对表达量分别为(1.92±0.09)和(2.42±0.21),与模型组相比均显著增加(P0.05)。结论:欧前胡素可能通过活化ERK1/2信号通路保护低氧诱导的心肌细胞损伤。     

尾加压素Ⅱ对正常及缺血-再灌注离体大鼠心脏的影响

在正常Langendorff灌流与缺血-再灌注(停灌20 min-复灌20 min)离体大鼠心脏模型,观察尾加压素Ⅱ(urotensin Ⅱ,UⅡ)对冠脉流量、心功能和心肌代谢的影响以及心肌UⅡ受体的功能,以探讨UⅡ的心脏效应。对正常心脏给予0.1、1和10 nmol/L UⅡ各5 min,然后换洗5 min,对停灌缺血-再灌注心脏在再灌注期给予1或10nmol/L UⅡ。监测心率、左室内压和左室内压升降的最大变化率等心功能指标,计算冠脉流量,测定冠脉流出液中总蛋白和肌红蛋白含量以及乳酸脱氢酶(LDH)活性。灌流结束后,测定心肌丙二醛(MDA)含量和质膜UⅡ结合位点(放射性配基结合法)。结果如下:(1)正常心脏灌流UⅡ后,冠脉流量和心功能呈浓度依赖下降,换洗后没有完全恢复。心肌蛋白、肌红蛋白和LDH漏出随UⅡ浓度的增加而增加,换洗后迅速减少。UⅡ组心肌MDA含量与对照组差异无显著性。(2)缺血-再灌注后,冠脉流量显著减少,心功能显著抑制,再灌注期心肌蛋白、肌红蛋白和LDH明显漏出;给予UⅡ后,上述变化增强,且高浓度组更强,与对照组差异有显著性(P<<0.01),再灌注后心肌MDA含量亦显著高于对照(P<0.01)。(3)缺血-再灌注心肌质膜UⅡ受体的B_(max)显著高于正常对照心肌(14.65±1.78vs20.53±1.98 fmol/mg pr,P<0.01),Kd值变化无统计学意义。上述结果表明,在正常     

沉默信息调节因子1通过诱导miR-221/222表达促进细胞自噬

微小RNA（microRNAs, miRNAs,）是一类强大的基因表达调控子,可在转录及转录后水平负调控靶基因的表达来参与生物学过程。沉默信息调节因子1 (silent information regulator1, SIRT1)底物众多,可通过去乙酰化作用参与多种细胞生命活动进程。尽管如此,SIRT1与非编码RNA如miRNA的表达调控关系仍有待深入研究。本文利用荧光定量PCR 检测发现,SIRT1与miR-221和miR-222的表达呈正相关：干扰SIRT1后,miR-221/222呈低水平表达;而过表达SIRT1则促进miR-221/222的表达。将miR-221/222基因簇启动子区序列插入pEZX-GA01构建双荧光素酶报告载体,与SIRT1过表达质粒或干扰序列共转至细胞。结果显示,SIRT1可显著提高miR-221/222启动子区活性,提示SIRT1可在转录水平调节miR-221/222的表达。进一步运用Western 印迹研究发现,在HEK293细胞中过表达miR-221/222可促进细胞的自噬能力,而抑制miR-221/222的表达可减弱自噬。此外,过表达SIRT1的同时抑制miR-221/222 的表达可减弱SIRT1的自噬诱导作用。综上所述,SIRT1可通过诱导miR-221/222的表达促进细胞自噬,其具体作用机制有待进一步探讨。     

Serotonin acts as a novel regulator of interleukin-6 secretion in osteocytes through the activation of the 5-HT2B receptor and the ERK1/2 signalling pathway

Interleukin-6 (IL-6) is a potent stimulator of osteoclastic bone resorption. Osteocyte secretion of IL-6 plays an important role in bone metabolism. Serotonin (5-HT) has recently been reported to regulate bone metabolism. The aim of this study was to evaluate the effect of serotonin on osteocyte expression of IL-6. The requirement for the 5-HT receptor(s) and the role of the extracellular signal-regulated kinase 1/2 (ERK1/2) in serotonin-induced IL-6 synthesis were examined. In this study, real-time PCR and ELISA were used to analyse IL-6 gene and protein expression in serotonin-stimulated MLO-Y4 cells. ERK1/2 pathway activation was determined by Western blot. We found that serotonin significantly activated the ERK1/2 pathway and induced IL-6 mRNA expression and protein synthesis in cultured MLO-Y4 cells. However, these effects were abolished by pre-treatment of MLO-Y4 cells with a 5-HT_2B receptor antagonist, RS127445 or the ERK1/2 inhibitor, PD98059. Our results indicate that serotonin stimulates osteocyte secretion of IL-6 and that this effect is associated with activation of 5-HT_2B receptor and the ERK1/2 pathway. These findings provide support for a role of serotonin in bone metabolism by indicating serotonin regulates bone remodelling by mediating an inflammatory cytokine.     

Metastasis suppressor protein 1 regulated by PTEN suppresses invasion,migration, and EMT of gastric carcinoma by inactivating PI3K/AKT signaling

Epithelial-mesenchymal transition (EMT) is a crucial event for cancer progression and metastasis. Metastasis suppressor protein 1 (MTSS1) is a metastasis suppressor in several cancers. In this study, we elucidated the potential physiological function of MTSS1 in the invasion and migration of gastric cancer (GC), and its distinct role in EMT and subsequently determined the potential molecular mechanism. We observed that MTSS1 expression was downregulated in GC tissues and several GC cell lines (SGC-7901, MGC-803, MKN-28, MKN-45, and BGC-823). Importantly, forced expression of MTSS1 drastically diminished the cell viability in both SGC-7901 and MKN-45 cells. Moreover, overexpression of MTSS1 attenuated the invasion ability of these two cell lines. In addition to the invasive capability, introduction of MTSS1 led to a loss of migratory potential. Furthermore, augmentation of MTSS1 exhibited the typical EMT phenotype switch, accompanied by enhanced the expression of vimentin and N-cadherin and reduced E-cadherin expression. Interestingly, MTSS1 also repressed transforming growth factor beta 1 (TGF-β1)-induced EMT. Our mechanistic investigations revealed that MTSS1 was positively regulated by the phosphatase and tensin homolog (PTEN), and it functioned as a tumor suppressor, possibly by inactivating the phosphoinositide 3-kinase (PI3K)/v-akt murine thymoma viral oncogene (AKT) pathway in GC cells. Collectively, our data provide insight into an important role for MTSS1 in suppressing tumor cell invasion, migration and EMT, which indicates that MTSS1 may act as a prospective prognostic biological marker and a promising therapeutic target for GC.     

Heme oxygenase 1 regulates apoptosis induced by heat stress in bovine ovarian granulosa cells via the ERK1/2 pathway

Heat stress can inhibit follicular development in dairy cows, and thus can affect their reproductive performance. Follicular granulosa cells can synthesize estrogen, that affects the development and differentiation of follicles by apoptosis. Heme oxygenase 1 (HO-1/heat shock protein 32) plays an antiapoptotic and cytoprotective role in various cells during stress-induced apoptosis, but little is known about its definitive function in bovine (ovarian) granulosa cells (bGCs). In our study, the roles and mechanism of HO-1 on the heat stress-induced apoptosis of bGCs were studied. Our results show that the expression of HO-1 was significantly increased under heat stress. Moreover, HO-1 silencing increased apoptosis, whereas its overexpression dampened apoptosis by regulating the expression of Bax/Bcl-2 and the levels of cleaved caspase-3. In addition, HO-1 can also play a cytoprotective role by affecting estrogen levels and decomposing heme to produce biologically active metabolite carbon monoxide (CO). Meanwhile, CO significantly increased the level of HO-1, decreased Bax/Bcl-2 levels, and inhibited the activation of extracellular signal-regulated kinase 1/2 (ERK1/2) signaling pathway. The apoptosis of ovarian GCs can affect the secretion of estrogen and lead to disorder of the ovarian microenvironment, thus affecting the normal function of the ovary. Our results indicate that HO-1 acts as a cytoprotective enzyme and plays a protective role in heat-induced apoptosis of bGCs. In conclusion, HO-1 and its metabolite CO inhibit the apoptosis of bGCs induced by heat stress through the ERK1/2 pathway. The results of this study provide a valuable clue for improving the fertility of heat stressed cows in summer.     

Thrombin-Induced Regulation of CD95(Fas) Expression in the N9 Microglial Cell Line: Evidence for Involvement of Proteinase-Activated Receptor<Subscript>1</Subscript> and Extracellular Signal-Regulated Kinase 1/2

Microglia are the immune cells of the CNS. Brain injury triggers phenotypic changes in microglia including regulation of surface antigens. The serine proteinase α-thrombin can induce profound changes in neural cell physiology via cleavage of proteinase-activated receptors (PARs). We recently demonstrated that pharmaceutical-grade recombinant human α-thrombin (rh-thr) induces a restricted set of proteolysis-dependent changes in microglia. CD95(Fas) is a cell-death receptor that is up-regulated in microglia by inflammatory stimuli. Here we characterized the effect of rh-thr on CD95(Fas) expression in the N9 microglial cell line. Dose–response and time course studies demonstrated maximal effects at 100 U/ml and 24 h, respectively. Regulation of expression was seen at both the surface protein and steady-state mRNA levels. The rh-thr-induced effects were mimicked by PAR₁ agonist peptides and blocked by pharmacologic inhibitors selective for extracellular signal-regulated kinase 1/2 (ERK 1/2). Rh-thr also induced a rapid and sustained phosphorylation of ERK 1/2. Thrombin-induced regulation of CD95(Fas) could modulate the neuroinflammatory response in a variety of neurological disorders.     

Spy1, a unique cell cycle regulator,alters viability in ALS motor neurons and cell lines in response to mutant SOD1-induced DNA damage

Increasing evidence indicates that DNA damage and p53 activation play major roles in the pathological process of motor neuron death in amyotrophic lateral sclerosis (ALS). Human SpeedyA1 (Spy1), a member of the Speedy/Ringo family, enhances cell proliferation and promotes tumorigenesis. Further studies have demonstrated that Spy1 promotes cell survival and inhibits DNA damage-induced apoptosis. We showed that the Spy1 expression levels were substantially decreased in ALS motor neurons compared with wild-type controls both in vivo and in vitro by qRT-PCR, western blotting, and Immunoassay tests. In addition, we established that over-expression of human SOD1 mutant G93A led to a decreased expression of Spy1. Furthermore, DNA damage response was activated in SOD1^G93A-transfected cells (mSOD1 cells). Moreover, decreased Spy1 expression reduced cell viability and further activated the DNA damage response in mSOD1 cells. In contrast, increased Spy1 expression improved cell viability and inhibited the DNA damage response in mSOD1 cells. These results suggest that Spy1 plays a protective role in ALS motor neurons. Importantly, these findings provide a novel direction for therapeutic options for patients with ALS as well as for trial designs, such as investigating the role of oncogenic proteins in ALS.     

Inhibition of extracellular signal-regulated kinase potentiates the apoptotic and antimetastatic effects of cyclin-dependent kinase inhibitors on metastatic DU145 and PC3 prostate cancer cells

Purvalanol and roscovitine are specific cyclin-dependent kinase (CDK) inhibitors, which have antiproliferative and apoptotic effects on various types of cancer. Although, the apoptotic accomplishment of purvalanol and roscovitine was elucidated at the molecular level, the underlying exact of drug-induced apoptosis through mitogen-activated protein kinase (MAPK) signaling still speculative. In addition, the role of CDK inhibitors in the downregulation of extracellular signal–regulated kinase 1/2 (ERK1/2)-mediated epithelial-mesenchymal transition (EMT) remains unclear. Here, we investigated the potential effect of each CDK inhibitors on cell proliferation, migration, and generation of reactive oxygen species due to the inhibition of MAPKs in metastatic DU145 and PC3 prostate cancer cells. We reported that purvalanol and roscovitine induced mitochondria membrane potential loss–dependent apoptotic cell death, which was also characterized by activation of several caspases, cleavage of poly (ADP-ribose) polymerase-1 in DU145 and PC3 cells. Cotreatment of either purvalanol or roscovitine with ERK1/2 inhibitor, U0126, synergistically suppressed cell proliferation, and induced apoptotic action. Also, ERK1/2 inhibition potentiated the effect of each CDK inhibitor on the downregulation of EMT processes via increasing the epithelial marker and decreasing mesenchymal markers through reduction of Wnt signaling regulators in DU145 cells. This study provides biological evidence about purvalanol and roscovitine have apoptotic and antimetastatic effects via MAPK signaling on prostate cancer cell by activation of GSK3β signaling and inhibition of phosphoinositide-3-kinase/AKT (PI3K/AKT) pathways involved in the EMT process.     

Cyclophilin A binds to AKT1 and facilitates the tumorigenicity of Epstein-Barr virus by mediating the activation of AKT/mTOR/NF-κB positive feedback loop

The AKT/mTOR and NF-κB signalings are crucial pathways activated in cancers including nasopharyngeal carcinoma (NPC), which is prevalent in southern China and closely related to Epstein-Barr virus (EBV) infection. How these master pathways are persistently activated in EBV-associated NPC remains to be investigated. Here we demonstrated that EBV-encoded latent membrane protein 1 (LMP1) promoted cyclophilin A (CYPA) expression through the activation of NF-κB. The depletion of CYPA suppressed cell proliferation and facilitated apoptosis. CYPA was able to bind to AKT1, thus activating AKT/mTOR/NF-κB signaling cascade. Moreover, the use of mTOR inhibitor, rapamycin, subverted the activation of the positive feedback loop, NF-κB/CYPA/AKT/mTOR. It is reasonable that LMP1 expression derived from initial viral infection is enough to assure the constant potentiation of AKT/mTOR and NF-κB signalings. This may partly explain the fact that EBV serves as a tumor-promoting factor with minimal expression of the viral oncoprotein LMP1 in malignancies. Our findings provide new insight into the understanding of causative role of EBV in tumorigenicity during latent infection.