中药调节内质网应激的研究进展

<正>内质网(endoplasmic reticulum, ER)是一种高度动态的细胞器，生理条件下内质网主要负责大多数蛋白的合成、折叠、组装、修饰以及脂质合成和Ca2+储存，当病理条件下新合成的蛋白质聚积并超过了内质网的最大处理能力，即可触发多种信号反应，即内质网应激(endoplasmic reticulum stress, ERS)[1]。中药可通过调控真核细胞内质网应激从而延缓疾病的发生与发展，因此，将内质网应激的定义与机制、     

内质网应激与神经系统疾病

内质网（endoplasmic reticulum,ER）是真核细胞中最重要的细胞器之一,附在内质网膜上的各种酶为生命活动过程中各种化学反应的正常进行创造必要条件。ER在细胞内具有正确蛋白质的合成转运、信号肽识别和糖基化修饰、钙离子的贮存和调节、信号转导等生理功能。     

内质网应激在眼科疾病中的研究进展

内质网是一种负责蛋白质合成、折叠以及转运,脂类生物合成,空泡运输以及胞内钙存储的多功能细胞器。内质网腔内未折叠蛋白质的蓄积及钙离子稳态的打破,诱发内质网应激,发生具有保护性的未折叠蛋白反应。内质网应激与多个信号通路相互联系,参与炎症、凋亡的发生发展,近年来得到越来越多的关注。本文就内质网应激发生机制及相关的眼科疾病的研究进展作一综述。     

中药基于内质网应激途径的神经保护作用研究进展

内质网应激（endoplasmic reticulum stress,ERS）及其诱导的神经细胞凋亡在神经退行性疾病（neurodegenerative diseases,NDD）的发生、发展过程中起着重要作用。大量研究证明,中医药或其有效成分能够通过PERK、ATF6和IRE1信号通路等ERS相关途径发挥调控作用,显著抑制ERS诱导的神经细胞凋亡,干预ERS诱发的神经损伤及相关疾病。本文综述近年来中药及其有效成分抑制ERS,发挥神经保护作用的相关机制研究进展,为阐释中医药的神经保护作用机制,防治NDD提供理论参考。     

中医药调节内质网应激防治疾病的研究进展

越来越多的证据表明内质网应激在多种疾病的病理过程中发挥重要作用。未折叠蛋白反应信号通路调节相关基因表达以维持内质网稳态或在内质网应激不缓解时介导凋亡。自噬可能作为对持续的内质网应激的一个代偿机制,对维持细胞稳态非常重要。文章综述了近5年中药单体、复方及其他中医治疗方法通过调节内质网应激相关通路,影响细胞凋亡和/或自噬,治疗疾病的研究成果,发现中医药方法干预内质网应激相关基因对多种疾病的治疗均有成效,其作用主要包括：抗肿瘤、保护神经、保护心肌、保护肝细胞、抗结核、改善胰岛素抵抗等方面,为相关疾病的治疗提供了潜在的新靶点。     

中医药基于内质网应激防治糖尿病肾病研究进展

糖尿病肾病（diabetic nephropathy,DN）是糖尿病最常见的微血管并发症,发病率逐年增高,是导致终末期肾脏病的主要原因。内质网稳态对维持机体正常功能具有重要意义。研究表明,内质网稳态失衡可诱发内质网应激（endoplasmic reticulum stress,ERS）,激活未折叠蛋白反应（unfolded protein response,UPR）介导的3条细胞适应性应答通路以恢复内质网稳态,适度的ERS对细胞具有保护作用,而ERS持续存在超过内质网自身调节平衡时会激活细胞凋亡信号通路,引起肾脏足细胞损伤、肾小管功能障碍,加速糖尿病肾病的进展。因此,ERS信号通路及其关键因子已成为防治DN的重要靶点。中医药可通过多成分、多靶点协同作用延缓糖尿病肾病的进展。文章基于内质网应激途径对中医药防治糖尿病肾病的现状进行综述,总结其主要的作用机制及相关靶点、调控通路,以期为糖尿病肾病的治疗研究提供参考。     

内质网应激与相关眼科疾病

内质网是一个非常重要的细胞器.当内质网应激发生,细胞内信号分子活化,启动未折叠蛋白反应,细胞最终得以适应性存活或者启动凋亡.诸如白内障、糖尿病性视网膜病变(diabetic retinopathy,DR)、青光眼、色素性视网膜炎(retinitis pigmentosa,RP)等眼科疾病的发生和发展都与内质网应激过程密切相关,就此研究动态予以综述.     

内质网应激在糖尿病及糖尿病肾病中的研究进展

内质网是控制蛋白质量的场所。大量的病理生理因素扰乱了内质网的功能,引起了内质网稳态的失调,导致内质网应激(ERS)。ERS主要由3条信号通路构成,适度的ERS能增强细胞的存活能力,过长、过强的ERS则会诱导细胞凋亡。1型糖尿病、2型糖尿病及糖尿病肾病(DN)中不同因素均可导致ERS,ERS通路的激活在这3种疾病的发生、发展过程中发挥着重要的作用,这或许会成为糖尿病及DN治疗的新思路。     

二氧化硅纳米颗粒致HUVEC内质网应激的机制

目的探讨二氧化硅纳米颗粒(SiNP)致人脐静脉内皮细胞(HUVEC)内质网应激(ERS)的分子机制。 方法用25、50、100 mg/L SiNP作用于HUVEC,蛋白质免疫印迹、免疫荧光技术检测未折叠蛋白反应(UPR)及其关键蛋白表达。 结果随SiNP作用剂量的增加,HUVEC的UPR及其下游蛋白表达显著上调(P＜0.01)。 结论SiNP可致HUVEC持续ERS,并促进下游关键蛋白表达。     

Effects of endoplasmic reticulum stress and related apoptosis on selective death of dopaminergic neurons

Objective： To explore the mechanism of endoplasmic reticulum stress（ERS） response and related apoptosis in dopaminergic neurons death. Methods： Nerve growth factor （NGF）-treatedPC12 cells were treated with 6-OHDA, MPP^＋ and rotenone. MTT assay and flow cytometry were used to measure the cell viability and the rate of celluar apoptosis induced by those neurotoxins. The expression of ERS-related gene XBP1, Grp78, CHOP, caspase-12 in drug-treated group and reserpine preincubafion group was determined with RT-polymerase chain reaction（RT-PCR） and immunohistochemistry. Results： After the exposure to different toxins, the viability of PC12 cells were decreased by 52%, 44%, 40% at 100μM6-OHDA, 75 μM MPP^＋, 20 nM rotenone for 24 h respectively. FCM assay confirmed time-dependent cell apoptosis （P 〈 0.01 ）. The gene and protein expression of XBP1, Grp78 in drug-treated group were significantly increased and reached their peaks 8 h after the treatment（P 〈 0.05）. The expression levels of CHOP and caspase-12 gene were increased 16-24 h after the treatment（P 〈 0.01 ）, but the expression level of caspase-12 was inhibited by reserpine preincubayion（P 〈 0.05）. Conclusion： The excessive ERS and relative activated cell apoptosis pathway may be associated with selective death of dopaminergic neurons.     

内质网应激在氟中毒大鼠肾损害中的作用

目的：　初步观察内质网应激在氟中毒大鼠肾组织中的变化,探索内质网应激在氟中毒肾损伤机制中的作用。方法：　48只Wistar 大鼠按体重平均分成4组：常食对照组、常食加氟组、低钙对照组和低钙加氟组;分别给予常食和低钙饮食,加氟组大鼠饮水中投氟化钠（NaF）（221 mg•L-1）3个月。实验结束后,取一侧肾脏制作病理切片,在光镜下观察形态学变化。取各组大鼠50 mg肾组织抽提总RNA,利用RT-PCR技术分析内质网应激相关基因Grp78、Xbp1、CHOP和PDI的表达水平。结果：光镜下可见,常食加氟组大鼠肾组织以近端小管和远端小管上皮细胞水肿和空泡变性为主;低钙加氟组大鼠肾组织近端小管和远端小管上皮细胞呈现水肿和空泡变性,伴有散在的坏死、轻度再生修复和肾间质充血;常食对照组和低钙对照组大鼠肾组织无明显变化。RT-PCR产物经半定量分析显示,低钙加氟组和常食加氟组大鼠肾组织Xbp1的表达较相应对照组明显增强（P<0.05）,低钙加氟组大鼠肾组织Grp78 mRNA表达较常食加氟组和低钙对照组明显增强（P<0.05或 P<0.01）;而低钙加氟组大鼠肾组织PDI的表达较常食加氟组明显下降（P<0.05）。各组大鼠肾组织CHOP表达差异无显著性（P>0.05）。结论：过量氟可造成肾组织损伤,低钙营养进一步加剧了氟对肾的损伤作用,而内质网应激很可能参与该损伤机制。     

热打击可通过调控内质网应激通路促进神经细胞凋亡

Objective To explore the role of endoplasmic reticulum stress in heat stress-induced apoptosis of human neuroblastoma SH-SY5Y cells. Methods SH-SY5Y cells were incubated at 43 ℃ for 2 h followed by further culture at 37 ℃ for 0, 3 h, or 6 h. With the cells cultured at 37 ℃ as the control, the cells exposed to heat stress were examined for morphological changes under optical microscope and changes in cell viability using CCK-8 assay. Flow cytometry was performed for detecting apoptosis of the cells following heat stress, and intracellular Ca2 + level in the cells was determined using flow cytometry and immunofluorescence confocal microscopy. The mRNA expression levels of caspase-12, BIP and XBP-1 in the cells were detected using qRT-PCR, and the protein expressions of caspase-12, BIP, P- JNK, JNK and XBP-1 were examined using Western blotting. The effect of pretreatment with 4-PBA on cell apoptosis following heat stress was analyzed with Western blotting. Results SH-SY5Y cells showed obvious cell shrinkage immediately after the exposure to heat stress, followed then by gradual cell stretching over time. The cell viability decreased significantly after heat stress (P=0.001), and the intracellular Ca2+ level increased significantly at 0 h and gradually recovered the normal level at 3 and 6 h. Heat stress induced significant increase in the protein expression of cleaved caspase-3 and time-dependent increase of caspase-12 (P=0.002) and BIP (P=0.008) expression at both the protein and mRNA levels. The expression of P-JNK/JNK protein increased significantly at 0 h (P=0.003) followed by gradual decrease; the expression levels of XBP-1 protein and mRNA gradually decreased after heat stress (P=0.005, P=0.002). Pretreatment with 4-PBA significantly reduced the expression level of cleaved caspase-3 in SH-SY5Y cells following heat stress. Conclusion Heat stress induces apoptosis of SH- SY5Y cells by triggering endoplasmic reticulum stress and the imbalance of intracellular calcium ion homeostasis.     

内质网与细胞凋亡

内质网 (endoplasmicreticulum ,ER)广泛存在于真核细胞中 ,是调节蛋白质合成及合成后折叠、聚集的场所 ,是调节细胞的应激反应及细胞钙水平的场所 ,也是胆固醇、类固醇及许多脂质合成的场所。ER应激在细胞凋亡中起重要作用 ,现就ER应激在细胞中的作用、ER应激与Ca2 + 水平的调节及与相关凋亡蛋白之间的关系等方面进行综述。     

大黄素对糖尿病大鼠肠平滑肌内质网应激及调控机制的研究

目的 探讨大黄素对糖尿病大鼠肠平滑肌细胞凋亡机制及调控机制.方法 SD大鼠分为对照组、糖尿病组与大黄素组,成模10周时,检测小肠推进率;TUNEL法测肠平滑肌细胞凋亡;免疫组织化学测细胞葡萄糖调节蛋白78 (GRP78)及Caspase-12蛋白表达.结果 糖尿病组与大黄素组大鼠于成模后出现多尿、多饮、多食、体质量减轻症状;血糖水平显著增高(P＜0.05).成模10周时,与对照组比较,糖尿病组大鼠小肠推进率显著下降(P＜0.05),肠平滑肌细胞凋亡率、GRP78、Caspase-12蛋白表达显著增加(P＜0.05).与糖尿病组比较,大黄素组小肠推进率显著增高(P＜0.05),肠平滑肌细胞凋亡率、GRP78、Caspase-12蛋白表达显著降低(P＜0.05).结论 内质网应激途径介导了糖尿病大鼠肠平滑肌细胞凋亡;大黄素可能降低糖尿病大鼠肠平滑肌内质网应激介导的细胞凋亡,从而改善肠动力.     

白芍总苷对糖尿病大鼠肝脏内质网应激的调节作用

目的 探讨白芍总苷( TGP)对糖尿病大鼠肝脏损害的保护作用是否与抑制内质网应激( ERS)有关. 方法 建立链脲佐菌素( STZ)诱导的糖尿病模型,随机分为对照组、模型组、TGP ( 50、100、200 mg/kg )给药组. 应用油红 O与Masson染色对肝组织行病理检查;采用免疫组化法检测肝组织ED-1表达;采用Western blot法检测GRP78、p-Perk及p-Eif2α的表达. 结果 TGP给药可降低糖尿病大鼠肝重增加及肝组织总胆固醇( TC)、三酰甘油( TG)及游离脂肪酸( FFA)水平. 模型组肝细胞油红O染色评分明显高于对照组( P <0. 01 );TGP 各给药组评分明显低于模型组( P <0. 01). Masson染色模型组肝纤维化评分明显高于对照组(P<0. 01);TGP 50、100、200 mg/kg给药组评分明显低于模型组( P<0. 01 ). 免疫组化显示模型组肝组织巨噬细胞浸润明显增加,各给药组均能抑制糖尿病肝组织巨噬细胞浸润的增加. Western blot显示糖尿病模型组肝组织GRP78、p-Perk及p-Eif2α表达明显高于对照组, TGP 给药组肝组织GRP78、p-Perk及p-Eif2α表达明显低于模型组. 结论 TGP对糖尿病肝损害有明显保护作用,其机制可能与其抗炎、抑制ERS有关.     

Hydrogen sulfide regulates vascular endoplasmic reticulum stress in apolipoprotein E knockout mice

Background  Atherosclerosis is an important cardiovascular disease, becoming a major and increasing health problem in developed countries. However, the possible underlying mechanisms were not completely clear. In 2009, our research group first discovered that hydrogen sulfide (H₂S) as a novel gastrotransmitter played an important anti-atherosclerotic role. The study was designed to examine the regulatory effect of hydrogen sulfide (H₂S) on endoplasmic reticulum stress (ERS) in apolipoprotein E knockout (apoE^-/-) mice fed a Western type diet.

Methods  C57BL/6 mice and homozygous apoE^-/- mice were fed a Western type diet. C57BL/6 mice were injected intraperitoneally with normal saline (5 ml/kg per day) as control group. The apoE^-/- mice were treated with the same dose of normal saline as the apoE^-/- group, injected intraperitoneally with sodium hydrosulfide (NaHS, an H₂S donor, 56 μmol/kg per day) as the apoE^-/-+NaHS group and injected intraperitoneally with DL-propargylglycine (PPG, a cystathionine-γ-lyase inhibitor, 50 mg/kg, per day) as the apoE^-/- +PPG group. After 10 weeks, the mice were sacrificed and the plasma lipids were detected. Sections of aortic root from these animals were examined for atherosclerotic lesions by HE and oil red O staining. The aortic ultrastructure and microstructure were analyzed with the help of light and electronic microscope. Glucose-regulated protein 78 (GRP78), caspase-12, copper-andzinc-containing superoxide dismutase (Cu/ZnSOD) and Mn-containing superoxide dismutase (MnSOD) protein expression in aortic tissues were detected with immunohistochemistry. The level of intracellular reactive oxygen species (ROS) were measured by using a commercial assay kit.

Results  Compared with control mice, apoE^-/- mice showed increased plasma levels of total cholesterol (TC), triglyceride (TG) and low density lipoprotein (LDL), decreased high density lipoprotein (HDL), increased aortic plaque size, destroyed ultra-structure of aortic tissue, and increased expression of GRP78 and caspase-12 proteins. Compared with apoE^-/- mice, H₂S donor-treated apoE^-/- mice showed a decreased plasma LDL level, lessened plaque necrosis and attenuated aortic ultra-structural disorder. H₂S donor-treatment induced GRP78 expression but suppressed caspase-12 expression in aortic lesions. However, compared with apoE^-/- mice, PPG treated apoE^-/- mice showed enlarged plaque size, more severe ultrastructural disorder of the aortic tissue and reduced GRP78 staining in aortic lesions. The plasma lipids and the staining of caspase-12 in apoE^-/- + PPG rats did not significantly differ from those in the apoE^-/-mice. Consistently, H₂S induced SOD expression, accompanied by a reduced level of ROS.

Conclusion  H₂S plays a regulatory role in aortic ERS and reduces atherosclerotic lesions in apoE^-/- mice fed with a Western type diet.