黄芪多糖对毒胡萝卜素诱导人结肠癌系HT29细胞内质网应激的影响

目的探讨黄芪多糖(Astragalus polysaccharides,AP)对毒胡萝卜素内酯(Thapsigargin,Tg)诱导人结肠癌系HT29细胞发生内质网应激(Endoplasmic Reticulum Stress,ERS)时内质网结构变化及相关分子GRP78和CHOP的影响。方法常规培养HT29细胞后,将细胞分为4组:①空白细胞组(Control组):细胞不做任何药物处理;②细胞模型组(Model组):采用1μmol/L Tg诱导HT29细胞建立ERS模型;③黄芪多糖低浓度组(AP-L组);④黄芪多糖高浓度组(AP-H组)。CCK8法检测黄芪多糖对HT29细胞活性,透射电镜观察内质网结构变化,Real-time PCR法检测ERS时GRP78、CHOP mRNA表达情况。结果黄芪多糖浓度分别为1、10μg/mL,且分别作用HT29细胞12、24、36、48 h时,细胞存活率随着浓度的增加而增加,说明对细胞无明显毒副作用。透射电镜观察Control组内质网结构呈网膜状结构,网膜腔不扩张;Model组内质网形态迥异,大小不一,呈空泡状改变,部分可见融合成簇现象;AP-L组内质网网膜腔扩张程度减轻,空泡体积减小和数量减少;AP-H组内质网形态基本恢复正常,呈网膜状结构,可见数量较少,形态较小的空泡状结构。Real-time PCR法检测结果:与Control组相比,Model组HT29细胞GRP78、CHOP mRNA表达明显增加(P<0.05);与Model组比较,AP-L组和AP-H组HT29细胞GRP78、CHOP mRNA表达均减少(P<0.05);与AP-L组比较,AP-H组HT29细胞GRP78、CHOP mRNA表达减少(P<0.05)。结论黄芪多糖能够抑制Tg诱导HT29细胞发生ERS,其机制可能与降低GRP78和CHOP的表达、减轻内质网应激有关。     

PERK信号通路介导结肠癌细胞对5-氟尿嘧啶耐药机制的研究

目的:观察PERK蛋白对结肠癌细胞药物敏感性的影响，并进一步探讨其相关作用机制。方法:结肠癌细胞系HCT116分为三组:空白对照（Control）组、下调PERK表达（si-PERK）组、阴性对照（si-NC）组；采用免疫荧光及RT-PCR验证转染效率；利用CCK-8实验检测下调PERK表达后结肠癌细胞对化疗药物5-FU的敏感性变化；Annexin V-FITC凋亡实验检测下调PERK表达对结肠癌细胞凋亡的影响；利用RT-PCR及Western Blot实验检测PERK信号通路中关键分子eIF2α、ATF4、CHOP、XIAP的mRNA及蛋白表达变化。结果:RT-PCR实验表明:与正常对照组相比，si-PERK 组mRNA的表达显著下降（P＜0.05）,免疫荧光提示转染效率达80%以上；CCK-8实验发现与si-NC组相比，5-FU对 si-PERK组细胞的半数抑制浓度（IC50）明显降低（P＜0.01）；Annexin V-FITC凋亡实验发现与si-NC组相比，si-PERK组细胞的凋亡发生率显著升高（P＜0.05）；RT-PCR及Western Blot实验发现与si-NC组相比，si-PERK组细胞中PERK信号通路下游关键分子eIF2α、ATF4、CHOP的mRNA及蛋白表达均明显降低（P＜0.05）。结论:在结肠癌细胞中，抑制PERK表达后，其可能通过下调eIF2α、ATF4、CHOP的表达促进细胞发生凋亡，从而促进细胞对化疗药物5-FU的敏感性。     

Effect of high volume hemofiltration on CHOP protein from a canine model of multiple organ dysfunction syndrome

Objective To observe the effect of high volume hemofiltration (HVHF) on the expression of CCAAT enhancer binding protein(CHOP) during the treatment of multiple organ dysfunction syndrome (MODS). To investigate the role of CHOP protein act in apoptosis pathway mediated by the endoplasmic reticulum stress. Methods Twelve Beagle dogs were subjected to hemorrhagic shock plus resuscltation and endotixemia to establish MODS model, then they were randomly divided into two groups: HVHF group (n=6) and MODS group (n=6). After endotoxin injection completed, the HVHF group received HVHF treatment for 24 hours; MODS group did not receive. Vivo experiments: Blood samples were obtained at different time points(before operation, 0 h, 6 h, 12 h, 24 h after the injection of endotoxin). The dogs were killed and the tissue samples from lung, liver and kidney were took, then the expression of CHOP mRNA was determined. Vitro experiments: human umbilical vein endothelial cells (HUVECs) were induced by two groups’ blood samples to establish the apoptosis model. Gene expression, protein quantification and cell apoptosis rate were determined before and after the interference. Results Vivo experiments: The levels of CHOP mRNA from lung, liver and kidney had no significant difference between the two groups (P＞0.05). Vitro experiments: (1)The expression of CHOP mRNA: Compared with MODS group, the expression levels of CHOP mRNA were significantly decreased in HVHF group at 6 h, 24 h after the injection of endotoxin (P＜0.05). Compared with before, the expression levels of CHOP mRNA in the two groups were both significantly decreased after CHOP siRNA interference (P＜0.05). (2)The expression of CHOP protein: Compared with MODS group, the expression levels of CHOP protein were significantly decreased in HVHF group at each time points (P＜0.05). Compared with before, the expression levels of CHOP protein in the two groups were both significantly decreased after CHOP siRNA interference(P＜0.05). (3)Endothelial cell apoptosis rate: Compared with the preoperative rate, the two group’s endothelial cell apoptosis rate was decreased significantly at each time points(P＜0.05). Compared with MODS group, the endothelial cell apoptosis rate was significantly decreased in HVHF group at each time points(P＜0.05). Compared with before, the endothelial cell apoptosis rate in the two groups was both significantly decreased after CHOP siRNA interference(P＜0.05). Conclusion In the treatment of MODS process, HVHF can reduce endothelial cell apoptosis which may be related to the inhibition of CHOP mRNA expression and protein synthesis.     

美罗华联合CHOP方案治疗侵袭性B细胞淋巴瘤

目的:探讨美罗华联合CHOP方案治疗侵袭性B细胞淋巴瘤疗效。方法:选取患者102例,采用数字表法分为常规组和联合组,分别给予CHOP方案和美罗华联合CHOP方案治疗,评价其治疗有效率和不良反应率。结果:联合组治疗有效性(88.24%)高于常规组(66.67%)(P0.05);两组不良反应率(21.57%vs25.49%)差异对比无统计学意义(P0.05)。结论:美罗华联合CHOP方案治疗侵袭性B细胞淋巴瘤相比于常规方案,在不增加患者不良反应率的前提下,可提高患者症状缓解率。     

GRP78与 CHOP在缺血再灌注损伤中的作用

缺血再灌注（ischemia-reperfusion ,IR）过程中多种因素可导致内质网应激（endoplasmic reticulum stress response,ERS）, ERS参与缺血再灌注（ ischemia-reperfusion injury,IRI）的发展过程。总结ERS抗凋亡标志物GRP78与促凋亡标志物CHOP在IRI中的作用。 IRI时GRP78与CHOP表达的变化及其作用。明晰GRP78与CHOP参与IRI的机制。     

Axon injury induced endoplasmic reticulum stress and neurodegeneration

Injury to central nervous system axons is a common early characteristic of neurodegenerative diseases. Depending on its location and the type of neuron, axon injury often leads to axon degeneration, retrograde neuronal cell death and progressive permanent loss of vital neuronal functions. Although these sequential events are clearly connected, ample evidence indicates that neuronal soma and axon degenerations are active autonomous processes with distinct molecular mechanisms. By exploiting the anatomical and technical advantages of the retinal ganglion cell(RGC)/optic nerve(ON) system, we demonstrated that inhibition of the PERK-e IF2α-CHOP pathway and activation of the X-box binding protein 1 pathway synergistically protect RGC soma and axon, and preserve visual function, in both acute ON traumatic injury and chronic glaucomatous neuropathy. The autonomous endoplasmic reticulum(ER) stress pathway in neurons has been implicated in several other neurodegenerative diseases. In addition to the emerging role of ER morphology in axon maintenance, we propose that ER stress is a common upstream signal for disturbances in axon integrity, and that it leads to a retrograde signal that can subsequently induce neuronal soma death. Therefore manipulation of the ER stress pathway may be a key step toward developing the effective neuroprotectants that are greatly needed in the clinic.