丹参二萜醌类活性成分通过PKCδ/PKD1μ信号通路抗胰腺癌的作用研究

摘要 目的 验证丹参二萜醌类活性成分对胰腺癌和多发性骨髓瘤的抑制效应，阐明其诱导胰腺癌和多发性骨髓瘤凋亡的作用机制。方法 胰腺癌细胞AsPC-1、BxPC-3用含10% gibco胎牛血清的RPMI1640培养液培养，按隐丹参酮组（30μM）、丹参新酮组（15μM）、去氢丹参新酮组（15μM）分别加药处理。cell-counting-kit-8（CCK8）法检测细胞存活率；AnnexinⅤ-FITC/PI流式细胞术检测细胞凋亡；Western Blot检测相关PKC同工酶磷酸化水平；对AsPC-1和BxPC-3细胞进行siRNA转染，Western Blot检测相关PKC同工酶磷酸化水平。结果 隐丹参酮组AsPC-1、BxPC-3细胞存活率分别为40.1%±5.0%、36.2%±5.4%；丹参新酮组AsPC-1、BxPC-3细胞存活率分别为52.1%±5.1%、47.2%±5.7%；去氢丹参新组AsPC-1、BxPC-3细胞存活率分别为46.1%±5.0%、42.2%±5.4%(P<0.01)。流式细胞术结果显示：AsPC-1组内空白对照组、隐丹参酮组、丹参新酮组、去氢丹参新酮组细胞的凋亡率分别为4.71%、30.10%、52.26%、42.30%；BxPC-3组内空白对照组、隐丹参酮组、丹参新酮组、去氢丹参新酮组细胞的凋亡率分别为5.10%、30.66%、33.76%、51.76%（P<0.01）。Western Blot检测显示隐丹参酮组、丹参新酮组、去氢丹参新酮组较空白对照组，胰腺癌AsPC-1、BxPC-3细胞p-PKD/PKCμ ser916、p-PKCδ thr505、p-PKD/PKCμ ser744/748的水平降低。Western Blot检测显示，siRNA沉默胰腺癌AsPC-1、BxPC-3细胞PKCδ，胰腺癌AsPC-1、BxPC-3细胞PKD/PKCμ ser744/748的磷酸化水平下调。结论 隐丹参酮、丹参新酮、去氢丹参新酮通过抑制PKCδthr505的磷酸化水平，继而PKD1μser744/748磷酸化水平下调，从而显著促进胰腺癌AsPC-1和BxPC-3细胞凋亡发生。     

奥曲肽诱导人结肠癌细胞凋亡与细胞周期的影响及机制

目的:探讨奥曲肽诱导人结肠癌细胞凋亡与细胞周期的影响及机制。方法:奥曲肽、GSK-3β抑制剂Li Cl单独或联合作用于人结肠癌SW480细胞后,用流式细胞术检测SW480细胞的凋亡与细胞周期,以及用DNA凝胶电泳实验进一步验证细胞凋亡;Western blot检测SW480细胞中GSK-3β、p-GSK3-β(Tyr216)及p-GSK-3β(Ser9)蛋白表达。结果:与未处理的空白对照组SW480比较,奥曲肽处理SW480细胞后,细胞凋亡率与G0/G1细胞明显升高,凝胶电泳出现典型的"梯形"DNA条带,总GSK-3β蛋白与p-GSK3β(Tyr216)表达明显上调,而p-GSK3β(Ser9)蛋白表达明显下降(均P<0.05);Li Cl单独作用对SW480细胞的凋亡与细胞周期无明显影响(均P>0.05),但与奥曲肽联合作用能明显削弱奥曲肽对SW480的促凋亡与细胞周期阻滞作用(均P<0.05)。结论:奥曲肽能有效诱导SW480细胞凋亡与细胞周期阻滞,该作用可能与其上调GSK-3β蛋白的表达,并调节GSK-3β蛋白的磷酸化水平有关。     

咖啡酸苯乙酯对结肠癌细胞JNK-paxillin信号通路的影响

目的:探讨咖啡酸苯乙酯(CAPE)对结肠癌细胞增殖抑制作用及对c-jun氨基酸末端激酶(JNK)信号通路的影响。方法:体外培养人结肠癌细胞株(HT-29),采用MTT法观察不同浓度的CAPE在不同时间段对HT-29细胞生长的抑制率;不同浓度的CAPE处理HT-29细胞24 h后,用Western blot法检测细胞中JNK及paxillin两种蛋白表达量的变化。结果:4个浓度(2.5,5.0,7.5,10.0μg/L)的CAPE均能明显抑制结肠癌细胞HT-29的增殖,且呈现明显的浓度和时间依赖性(均P<0.01);4个浓度的CAPE均能降低JNK和paxillin蛋白表达水平,且呈明显的浓度依赖性(均P<0.01)。结论:CAPE可在体外抑制人结肠癌细胞HT-29的增殖,机制可能与其降低JNK-paxillin信号通路的活性有关。     

Antinociceptive Effect of Najanalgesin from Naja Naja Atra in a Neuropathic Pain Model via Inhibition of c-Jun NH2-terminal Kinase

Background:

Najanalgesin, a toxin isolated from the venom of Naja naja atra, has been shown to exert significant analgesic effects in a neuropathic pain model in rats. However, the molecular mechanism underlying this protective effect of najanalgesin is poorly understood. The present study sought to evaluate the intracellular signaling pathways that are involved in the antinociceptive effect of najanalgesin on neuropathic pain.

Methods:

The antinociceptive properties of najanalgesin were tested in hind paw withdrawal thresholds in response to mechanical stimulation. We analyzed the participation of the mitogen-activated protein kinase p38, extracellular-regulated kinase (ERK), and c-Jun N-terminal kinase (JNK) by western blot analysis. This inhibition of JNK was confirmed by immunohistochemistry.

Results:

The phosphorylation levels of JNK (as well as its downstream molecule c-Jun), p38, and ERK were significantly increased after injury. Najanalgesin only inhibited JNK and c-Jun phosphorylation but had no effect on either ERK or p38. This inhibition of JNK was confirmed by immunohistochemistry, which suggested that the antinociceptive effect of najanalgesin on spinal nerve ligation-induced neuropathic pain in rats is associated with JNK activation in the spinal cord.

Conclusion:

The antinociceptive effect of najanalgesin functions by inhibiting the JNK in a neuropathic pain model.     

Involvement of Protein Kinase C in Ethanol-Induced Inhibition of NMDA Receptor Function in Cerebellar Granule Cells

Ethanol inhibits N -methyl- d -aspartate (NMDA)-stimulated increases in intracellular Ca²⁺ in cerebellar granule cells apparently by reducing the potency of glycine to act as a co-agonist at the NMDA receptor. The inhibitory effect of ethanol on the NMDA response in these cells can be reversed not only by a high concentration of glycine, but also by the protein kinase inhibitors, staurosporine and calphostin C. We previously showed that activation of protein kinase C in cerebellar granule cells also resulted in inhibition of the NMDA response, and in decreased potency of glycine at the NMDA receptor. Furthermore, the inhibitory effects of ethanol and protein kinase C activation are not additive. These results suggest a role for protein kinase C in ethanol inhibition of NMDA responses in cerebellar granule cells. In contrast, although ethanol can inhibit the response to kainate in these cells in a "competitive" manner, this response is not affected by activation of protein kinase C.     

VEGF反义寡核苷酸对胆囊癌细胞VEGF,Flt-1及KDRmRNA表达和VEGF蛋白分泌的影响

目的:体外研究Oligofectamine介导的VEGF反义寡核苷酸(antisense oligodeoxynucleotide,ASODN)转染对人胆囊癌GBC-SD细胞VEGF,Flt-1及KDR mRNA表达和VEGF蛋白分泌的影响.方法:运用Oligofectamine介导的VEGF反义寡核苷酸(ASODN)和错义寡核苷酸(Scrambled Oligodeoxynucleotide,SODN)转染人胆囊癌细胞GBC-SD,半定量RT-PCR检测转染后各组细胞不同时间的VEGF,Flt-1及KDR mRNA表达变化,ELISA测定转染后各组细胞培养上清液VEGF蛋白浓度.结果:半定量RT-PCR发现ASODN组及ASODN Oligofectamine组24,48,72,96 h VEGF(ASODN组VEGF165:0.686±0.033,0.569±0.049,0.489±0.036,0.716±0.017;ASODN组VEGF121:0.462±0.046,0.338±0.034,0.219±0.022,0.471±0.038;ASODN Oligofectamine组VEGF165:0.601±0.021,0.465±0.042,0.416±0.023,0.662±0.035:ASODN Oligofectamine组VEGF121:0.408±0.014,0.286±0.019,0.157±0.021,0.418±0.037)、Flt-1(ASODN组:0.694±0.019,0.562±0.045,0.435±0.042,0.724±0.026;ASODN Oligofectamine组:0.609±0.018,0.442±0.049,0.314±0.015,0.614±0.029)及KDR(ASODN组:0.667±0.063,0.490±0.033,0.301±0.029,0.665±0.068;ASODN Oligofectamine组:0.523±0.048,0.432±0.027,0.218±0.036,0.524±0.037) mRNA的表达显著低于Control组(P<0.05),且ASODN Oligofectamine的抑制作用比ASODN强(P>0.05).ELISA测定结果显示ASODN组(281.26±18.62,526.44±34.95,791.13±20.99)及ASODN Oligofectamine组(250.7±14.57,506.09±19.14,711.79±19.91)24,48,72 h VEGF蛋白的分泌浓度均显著低于Control组(394.23±16.26,711.6±26.21,933.85±28.65)(P<0.05),且ASODN Oligofectamine的抑制作用比ASODN强(P>0.05).结论:Oligofectamine介导的VEGF ASODN能抑制GBC-SD细胞VEGF,Flt-1及KDR mRNA表达和VEGF蛋白分泌.