未折叠蛋白反应参与小鼠急性肾缺血/再灌注损伤

目的 探讨未折叠蛋白反应(UPR)在小鼠急性肾缺血/再灌注损伤中的作用.方法 将C5786小鼠分为正常、假手术组和0、4、12、24 h手术组(分别于术后0、4、12和24 h处死小鼠),留取各组小鼠的左侧肾脏.苏木精一伊红(H-E)、过碘酸雪夫反应(PAS)和脱氧核糖核苷酸末端转移酶介导的缺口末端标记法(TUNEL)染色观察各组肾脏组织学变化,Western印迹法和实时聚合酶链反应(PCR)检测葡萄糖调节蛋白78(GRP78)和caspasel2在各组小鼠肾组织中的表达.结果 H-E、PAS染色可见24 h手术组的肾小管上皮细胞坏死明显,病变最重的部位为外髓外带近端小管,肾小管坏死评分为(2.930 0±0.131 1)分,显著高于其他组(P值均<0.01).TUNEL染色可见24 h手术组的肾小管上皮细胞凋亡指数为(36.17±7.53)%,显著高于其他各组(P值均<0.01).Western印迹法.结果 显示,12 h手术组的GRP78和caspase12蛋白水平显著高于其他各组(P值均<0.01).实时PCR.结果 显示,4 h手术组的GRP78和caspasel2 mRNA水平显著高于其他各组(P值分别<0.01、0.05).结论 在夹闭左侧肾动脉致急性肾缺血/再灌注损伤模型中,小鼠左侧肾脏组织学损伤显示再灌注后24 h最严重.GRP78和caspasel2在再灌注后其mRNA和蛋白表达水平明显升高或激活,其变化早于组织学改变.提示UPR可能在急性肾缺血/再灌注损伤中发挥重要作用.     

Olanzapine potentiates neuronal survival and neural stem cell differentiation: regulation of endoplasmic reticulum stress response proteins

Summary Recent clinical neuroimaging studies have suggested that morphological brain changes occur and progress in the course of schizophrenia. Although the neurogenetic and neurotrophic effects of antipsychotics are considered to contribute to the prevention of reduction in brain volume, the cellular molecular mechanisms of action of antipsychotics have not yet been elucidated. We examined the effects of antipsychotics on the endoplasmic reticulum (ER) stress-induced damages of neurons and neural stem cells (NSCs) using cultured cells. In the neuronal cultures, the atypical antipsychotic olanzapine protected neurons from thapsigargin (1 μM)-induced injury. It was observed that a low concentration of thapsigargin (10 nM) that did not affect the neuronal survival could reduce neuronal differentiation of cultured NSCs, suggesting a role of ER stress in the differentiation function of NSCs. Treatment with olanzapine increased the neuronal differentiation suppressed by the exposure to thapsigargin (10 nM). The thapsigargin-induced ER chaperones, GRP78, which indicate the ER stress condition of the cell, were decreased by the treatment with the atypical antipsychotics olanzapine and quetiapine but not by the typical antipsychotic haloperidol. These results indicate that the amelioration of ER-stress might be involved in the cellular mechanisms of atypical antipsychotics to produce neuroprotective and neurogenetic actions in neurons and NSCs, suggesting potential roles of these drugs for treatment of schizophrenia.     

依达拉奉对大鼠脑缺血急性期内质网应激的保护作用

目的：研究依达拉奉对大鼠脑组织缺血急性期引起的内质网应激（endoplasmic reticulum stress,ERS）的保护作用。方法：采用线栓法制备大鼠右大脑中动脉供血区缺血模型,通过脑组织含水量的测定和神经功能缺损评分来评价不同剂量（3．0、10．0mg／kg）依达拉奉的脑保护作用,并通过进一步检测与ERS相关的分子葡萄糖调节蛋白-78（GRP78）和caspase-12的表达量变化,来观察依达拉奉的脑保护作用与脑组织ERS的相关性。结果：不同剂量依达拉奉均可以使脑缺血急性期水肿的脑组织含水量减少,使大鼠神经功能评分改善,使大鼠脑缺血后高表达的GRP78出现下调,caspase-12的激活也受到抑制。结论：依达拉奉具有一定的脑保护作用,其机制可能与抑制脑组织缺血时的ERS有关。     

Mechanical ventilation in ARDS: a state-of-the-art review

Mechanical ventilation is an essential component of the care of patients with ARDS, and a large number of randomized controlled clinical trials have now been conducted evaluating the efficacy and safety of various methods of mechanical ventilation for the treatment of ARDS. Low tidal volume ventilation (相似文献   

高糖通过环加氧酶2依赖性途径诱导GRP78表达改变

目的： 观察高糖慢性处理对血管内皮细胞内质网应激标志蛋白葡萄糖调节蛋白78（GRP78）表达的影响及其作用机制。方法：培养的HUVECs细胞用含正常糖（5.5 mmol/L）或高糖（30 mmol/L）的培养基处理不同时间后,用MTT法测定细胞存活率,流式细胞仪测定细胞凋亡,Western blotting法测定蛋白表达情况。结果：与相应对照组相比,HUVECs细胞经高糖孵育24-48 h 后,GRP78蛋白表达量先增加后减少;而环加氧酶-2（COX-2）蛋白表达量逐渐增加。COX-2选择性抑制剂尼美舒利与高糖共孵育后,可明显抑制高糖引起的GRP78蛋白表达改变;同时尼美舒利可抑制高糖孵育48 h 后诱导的细胞凋亡。结论：高糖慢性处理可诱导HUVECs细胞GRP78表达先增加后减少,此过程依赖于COX-2蛋白的上调。     

非小细胞肺癌体外化疗药物敏感性与GRP94表达的相关性

[目的]探讨非小细胞肺癌(NSCLC)对8种化疗药物的体外敏感性与GRP94表达的相关性。[方法]用四噻唑蓝(MTT)法检测52例手术切除新鲜NSCLC组织8种化疗药物体外敏感性;免疫组织化学方法检测肺癌组织GRP94表达。采用Spearman法进行相关性分析。[结果]NSCLC52例对紫杉醇(PTX)、阿霉素(ADM)、卡铂(CBP)、拓扑替康(TPT)、长春瑞滨(NVB)、长春新碱(VCR)、顺铂(DDP)和鬼臼乙叉苷(VP-16)8种化疗药物的耐药率分别为42.31%、57.69%、63.46%、65.38%、67.31%、73.08%、78.85%和90.38%。其中,14例表现为完全耐药;且其高表达与肺癌细胞对VP-16的耐药明显相关(P<0.05)。[结论]检测GRP94表达对推测NSCLC对VP-16的耐药性具有参考意义。     

Cucurbitacin B-induced G2/M cell cycle arrest of conjunctival melanoma cells mediated by GRP78–FOXM1–KIF20A pathway

Conjunctival melanoma (CM) is a rare and fatal malignant eye tumor. In this study, we deciphered a novel anti-CM mechanism of a natural tetracyclic compound named as cucurbitacin B (CuB). We found that CuB remarkably inhibited the proliferation of CM cells including CM-AS16, CRMM1, CRMM2 and CM2005.1, without toxicity to normal cells. CuB can also induce CM cells G2/M cell cycle arrest. RNA-seq screening identified KIF20A, a key downstream effector of FOXM1 pathway, was abolished by CuB treatment. Further target identification by activity-based protein profiling chemoproteomic approach revealed that GRP78 is a potential target of CuB. Several lines of evidence demonstrated that CuB interacted with GRP78 and bound with a K_d value of 0.11 μmol/L. Furthermore, ATPase activity evaluation showed that CuB suppressed GRP78 both in human recombinant GRP78 protein and cellular lysates. Knockdown of the GRP78 gene significantly induced the downregulation of FOXM1 and related pathway proteins including KIF20A, underlying an interesting therapeutic perspective. Finally, CuB significantly inhibited tumor progression in NCG mice without causing obvious side effects in vivo. Taken together, our current work proved that GRP78–FOXM1–KIF20A as a promising pathway for CM therapy, and the traditional medicine CuB as a candidate drug to hinder this pathway.     

Endoplasmic reticulum stress is activated in light-induced retinal degeneration

Exposure to excessive levels of light induces photoreceptor apoptosis and has previously been used as a model for the study of retinal degeneration. During the light exposure, intracellular calcium levels increase, and reactive oxygen species (ROS) are generated, which have been shown to cause endoplasmic reticulum (ER) stress. In the present study, we investigated the role of ER stress in light-induced photoreceptor apoptosis. Our study demonstrated that, after light exposure, the ER stress sensors including glucose-regulated protein-78 (GRP78/BiP), caspase-12, phospho-eukaryotic initiation factor 2 alpha (eIF2 alpha), and phospho-pancreatic ER kinase (PERK) were significantly up-regulated in a time-dependent manner. The up-regulation of these proteins coincided with or preceded the photoreceptor apoptosis indicated by TUNEL. These data showed that ER stress played an important role in light-induced photoreceptor apoptosis. Therefore, ER stress modulators could be strong candidates as therapeutic agents in the treatment of retinal degenerative diseases.