内质网应激在糖尿病肾病中的研究进展

内质网是参与蛋白质质量控制和细胞内稳态的重要细胞器,其稳态失衡可导致内质网应激。适度的内质网应激是细胞自我保护的重要机制之一,但过度或持续的内质网应激可导致细胞损伤。近年来研究发现,内质网应激与糖尿病时肾脏固有细胞损伤密切相关,参与了糖尿病肾病的发生、发展过程,本文就内质网应激与糖尿病肾病关系的进展作一综述。     

内质网应激在糖尿病肾病中的研究进展

内质网（ endoplasmic reticulum,ER）广泛存在于真核细胞中,是细胞内合成蛋白质并进行折叠、寡聚化加工和细胞内钙储存的重要场所。病理生理条件,包括营养不足、营养过剩、蛋白质糖基化变化、ER钙含量改变和氧化应激等,均可干扰正常蛋白质折叠,错误折叠或未折叠蛋白质在内质网腔内积聚诱发细胞毒性反应[1]。因此,细胞进化出了复杂的信号系统来处理积聚的未折叠蛋白质、调节ER膜结构和分泌蛋白。     

糖尿病肾病和糖尿病视网膜病变应激相关关键基因的生物信息学分析

目的:通过生物信息学方法分析共同影响糖尿病肾病(diabetic nephropathy, DN)和糖尿病视网膜病变(diabetic retinopathy, DR)发生发展的应激相关关键基因。方法:从DisGeNET、CTD、Genecards数据库收集DN和DR的共致病基因数据,通过STRING数据库和Cytoscape软件构建蛋白互作网络图,进行共致病基因的GO和KEGG富集分析。同时,利用“limma”包筛选出GEO数据库中DN和DR数据集的共同差异基因,通过MCC插件筛选出Top20基因,并对两个芯片数据集进行GSEA富集分析。筛选出上述两组基因数据共同的应激相关关键基因,对其进行相关性和富集分析。最后,借助GeneMANIA、NetworkAnalyst 3.0、DGIdb数据库,构建蛋白互作网络以及TF-miRNA-gene网络,并预测应激相关关键基因的靶向治疗药物。结果:我们发现了5个高度正相关的应激相关关键基因(CCL2、THBS1、PECAM1、SPARC、POSTN),在高糖环境下,它们可通过介导应激反应影响肾脏以及视网膜的细胞外基质重构和炎症。同时,我们预测了...     

MrgD通过抑制内质网应激调节肝癌细胞脂肪酸代谢

目的 抑制脂肪酸和胆固醇的合成可以有效降低肝癌细胞脂肪积累或脂质代谢,从而抑制肝细胞癌发生.本研究旨在探讨MrgD对肝癌细胞脂肪代谢的作用及机制.方法 借助慢病毒包装的重组MrgD表达质粒及MrgD干扰质粒,分别建立稳定性过表达和低表达MrgD的HepG2细胞株.利用游离脂肪酸诱导构建体外细胞脂肪变性模型,通过油红O染...     

内质网应激对树突状细胞表面晚期糖基化终产物受体表达的影响

目的:晚期糖基化终产物受体(RAGE)与其配体结合在炎症及免疫反应中具有重要作用.本研究探讨内质网应激(ERS)在高迁移率族蛋白B1(HMGB1)诱导树突状细胞(DC)表面RAGE上调中的作用及意义.方法:分离正常BALB/c小鼠脾脏DC进行体外培养,给予HMGB1刺激后检测DC表面RAGE表达水平及细胞ERS相关分子...     

小窝蛋白3在小鼠糖尿病心肌病中的作用：与内质网应激的关系

目的评价小窝蛋白3(Cav-3)在小鼠糖尿病心肌病中的作用及其与内质网应激的关系。方法在体实验:清洁级健康成年雄性野生型小鼠16只, 体质量18～20 g, 采用随机数字表法分为2组(n=8):对照组(Control组)和糖尿病心肌病组(DCM组), 另取Cav-3 KO小鼠8只为Cav-3 KO+糖尿病心肌病组(Cav-3 KO+DCM组)。采用高脂饮食联合腹腔一次性注射链脲佐菌素100 mg/kg的方法制备小鼠2型糖尿病模型, 8周时采用心脏超声测定小鼠左心射血分数(EF)、左室短轴缩短率(FS)、左室收缩末期容积(LVESD)、左室舒张末期容积(LVEDD)。随后处死小鼠取心脏, HE染色观察心肌组织形态学结果。离体实验:小鼠来源的HL-1心肌细胞, 采用随机数字表法分为3组(n=6):正常糖培养组(NG组)、高糖组(HG组)和高糖+甲基-β-环糊精组(HG+β-CD组)。高糖模型采用专用培养基加入50%葡萄糖至终浓度达到30 mmol/L, 持续培养36 h。采用LDH、CCK8试剂盒评估细胞损伤情况。采用Western blot法检测心肌组织与HL-1细胞内质网应激相关蛋白结...     

内质网应激与肥胖、胰岛素抵抗、2型糖尿病

细胞应激涉及线粒体、内质网、细胞核等细胞器的应激，它们既相对独立，又相互作用。内质网（endoplasmic reticulum，ER）是细胞合成、加工蛋白质和贮存Ca^2＋的主要场所，对应激极为敏感，其功能紊乱时出现错误折叠与未折叠蛋白在腔内聚集以及Ca^2＋平衡紊乱的状态，称为ER应激。ER应激对决定应激细胞的结局如抵抗、适应、损伤或凋亡有重要作用，近年来有关其信号通路与效应的研究非常活跃。包括肥胖、胰岛素抵抗（IR）、2型糖尿病（DM）在内的代谢综合征已经成为危害人类健康的最严重的疾病之一。2型DM中超过85％的人表现为肥胖，同时，全球肥胖人口的增加又大大提高了代谢综合征尤其是IR和2型DM的发病率。但是这些疾病代谢紊乱的分子机制以及其彼此之间的相互关联仍未完全阐明。     

LncRNA HCG18调控miR-185-5p/AGER轴影响糖尿病肾病内质网应激和自噬

目的:本研究旨在探讨LncRNA HCG18调控miR-185-5p/AGER轴对糖尿病肾病（diabetic nephropathy,DN）内质网应激和自噬的影响。方法:收集DN患者肾脏组织,建立高糖（high glucose,HG）诱导的足细胞损伤模型。检测DN患者肾组织与DN细胞模型中HCG18的表达。确定HCG...     

Ubiquitination and endoplasmic reticulum stress of renal intrinsic cells in hyperglycemia

Objective To investigate the effects of hyperglycemia on ubiquitination and endoplasmic reticulum stress in renal intrinsic cells (podocytes and proximal tubular epithelial cells) and its role in pathogenesis of diabetic nephropathy. Methods Diabetic mice were induced by streptozotocin injection. After 16 weeks of hyperglycemia, immunofluorescence was used to detect the expressions of ubiquitination and glucose-regulating protein 94 (GRP94) in renal cortex and medulla area of kidney sections. Primary mouse podocyte and proximal tubular epithelial cells were isolated by flow cytometry, and exposed to 30 mmol/L glucose for indicated time (1 d, 3 d and 7 d). Their ubiquitination and GRP94 expressions were evaluated by Western blotting. Results Diabetic mice presented microalbuminuria and slightly widened mesangium was found in glomerular area. Ubiquitinated proteins, mainly localized in podocytes and tubular epithelial cells, exhibited an apparently higher expression in diabetic mice than control mice (all P＜0.05). Hyperglycemia promoted the ubiquitination in a time-dependent manner. Compared with their normal cells, primary mouse podocyte and primary tubular epithilial cells treated with high glucose for 3 d and 7 d showed increased ubiquitinated protein (all P＜0.05). GRP94 was interspersed in podocytes and proximal tubular epithelial cells. Expression of GRP94 was significantly increased in glomerular area of diabetic mice and podocyte with 3 and 7 day-high glucose as compared with those in their control groups (all P＜0.05). GRP94 expression had no significant change in tubular area and tubular epithilial cells treated with high glucose. Conclusions Hyperglycemia may lead to accumulation of ubiquitinated proteins in intrinsic kidney cells. The imbalance of protein homeostasis in podocyte may contribute to podocyte injury during the onset of diabetic nephropathy.     

Effect of endoplasmic reticulum stress on the activation of high glucose-induced monocytes

Objective To observe the effects of endoplasmic reticulum stress (ERS) on the activation of monocytes induced by high glucose and explore the underlying mechanism. Methods The monocyte cell line THP-1 was stimulated with high glucose, and then treated with molecular chaperone betaine. The levels of glucose regulation protein 78 (GRP78) and p-JNK, which were associated with ERS were detected by real-time PCR and Western blotting. The proliferation of the cell line was detected by MTT method. Transwell and immunofluorescence were applied to observe the chemotaxis and phenotype of cells respectively. Results The levels of GRP78 and p-JNK of THP-1 cells stimulated by high glucose were significantly increased compared with the normal control group (all P＜0.05). The proliferation and chemotactic were also enhanced (all P＜0.05). The number of cells in M1 phenotype was increased remarkably (P＜0.05). All the indexes above could be rescued by betaine. Conclusion The activation of THP-1 cells can be induced by high glucose through ERS, while molecular chaperone betaine can reverse the activation.     

衣霉素诱导内质网应激对树突状细胞成熟分化的影响

目的:内质网应激(ERS)是真核细胞中普遍存在的适应性应激反应,本研究应用ERS特异性诱导剂衣霉素(TM)体外刺激小鼠脾脏树突状细胞(DC),观察DC功能状态的改变情况.方法:分离正常BALB/c小鼠脾脏DC进行体外培养,给予ERS特异性诱导剂TM刺激,观察不同剂量、不同作用时间TM刺激与DC表面共刺激分子表达及分泌功...     

Regulation of melatonin on Toll-like receptor 4 signaling in diabetic db/db mice kidneys

Objective To investigate the regulation of melatonin (MT) on Toll-like receptor 4 (TLR4) signaling in diabetic db/db mice kidneys. Methods The 48 10-week-old male db/db mice were randomly divided into db/db group, db/db+MT 50 μg/kg group, db/db+MT 100 μg/kg group and db/db+MT 200 μg/kg group, each consisting of 12 mice. These mice received i.p. injections of MT These mice received i.p. injections of MT [dissoved in phosphate buffer solution (PBS)/ dimethylsulfoxide (DMSO) solution, given every day]. Alternatively, 12 db/m mice served as the control group. db/m and db/db group were injected i.p. with the same volume of PBS/DMSO solution. The animals were sacrificed after 12 weeks of dosage administration. Blood glucose (BG), body weight (BW), kidney weight (KW) and 24 h urinary albumin excretion rate (UAER) were determined; Kidney pathological lesions were evaluated by renal pathological staining. Immunohistochemistry of renal TLR4, NF-κB p65, and ED-1 was performed to determine the immunoreactivity. Western blotting was used to detect the expression of renal TLR4, myeloid differentiation factor 88 (MyD88), TIR-domain-containing adaptor inducing interferon-β (TRIF), interferon regulatory factor 3 (IRF-3) and NF-κB p65, while the mRNA expressions of renal tumor necrosis factor -α (TNF-α) and monocyte chemotactic protein-1 (MCP-1) were evaluated by real-time PCR. Results Compared with control group, the levels of BG, BW, KW and UAER were much higher in db/db mice group (P＜0.01), while KW in db/db+MT (100, 200 μg/kg) groups and UAER level in db/db+MT (50, 100, 200 μg/kg) groups were distinctly decreased compared with those in db/db group (P＜0.01). In week 12 db/db mice, the glomerular mesangial expansion index and tubulointerstitial injury index were increased compared with those in db/m mice (P＜0.01). The above kidney histopathologic lesions were distinctly ameliorated by 50, 100, 200 μg/kg MT (P＜0.05). Immunohistochemistry intensity of renal TLR4, NF-κB p65 and ED-1 displayed obvious differences between db/m mice and db/db mice (P＜0.01), and that were remarkably decreased in db/db+MT (50, 100, 200 μg/kg) mice compared with db/db mice (P＜0.05). Western blotting showed that the protein expression of renal TLR4, MyD88, TRIF, IRF-3 and NF-κB p65 were stronger in db/db group compared with those in db/m group (P＜0.05) and weaker in db/db+MT (50, 100, 200 μg/kg) groups compared with those in db/db group (P＜0.05). Futhermore, the mRNA expressions of renal MCP-1 and TNF-α were higher in db/db group compared with those in db/m group (P＜0.01) and lower in db/db+MT (50, 100, 200 μg/kg) groups compared with those in db/db group (P＜0.01). Conclusion Melatonin may partly down-regulate TLR4 signaling pathway to inhibit Inflammatory reaction and alleviate kidney injury in diabetic db/db mice.     

microRNA-215在糖尿病肾病小鼠肾组织中的表达及意义

目的 探讨microRNA-215( miR-215)在糖尿病肾病(DN)小鼠肾组织中的表达变化规律及在DN发病中的作用.方法 选择4周龄的2型糖尿病肾病db/db小鼠(实验组)和db/m小鼠(对照组),采用实时荧光定量PCR法动态检测8、12及16周龄时肾组织miR-215的表达变化;实时荧光定量PCR和Western印迹法、免疫组化法测定连环蛋白β互动蛋白1( CTNNBIP1)的mRNA及蛋白的表达;双荧光素酶报告法确证miR-215对CTNNBIP1表达的直接调控作用.结果 (1)随着周龄的增加,db/db小鼠肾小球逐渐肥大、节段性系膜细胞增生和系膜基质积聚.(2)与同周龄的db/m小鼠比较,8、12及16周龄的db/db小鼠体质量(BW)、血糖( Glu)及24 h尿白蛋白排泄量(UAE)均显著增加(均P＜0.05).(3)随着周龄的增加,db/db小鼠肾脏组织miR-215表达显著高于同周龄的db/m小鼠(P＜0.05).(4)与同周龄的db/m小鼠比较,db/db小鼠肾脏组织CTNNBIP1 mRNA和蛋白均显著降低(均P＜0.05).(5)应用双荧光素酶报告法证实,miR-215可显著抑制CTNNBIP1的表达(P＜0.01).结论 miR-215表达上调可能通过抑制CTNNBIP1的表达参与DN的发生、发展.     

4-苯基丁酸对糖尿病肾病大鼠的作用

目的 探讨化学分子伴侣4-苯基丁酸（4-PBA）对糖尿病肾病（DN）大鼠的治疗作用及其机制。 方法 54只大鼠随机分为正常对照组（NC）、糖尿病肾病组（DN）和4-PBA治疗组（4-PBA）,每组各18只。在治疗第4、8及12周末分别检测各组大鼠肾质量指数（KI）、24 h尿蛋白排泄率（UAER）、血肌酐（Scr）、尿素氮(BUN)、尿丙二醛（MDA）含量和超氧化物岐化酶（SOD）活性;观察肾脏病理改变;实时荧光定量PCR法检测各组大鼠肾组织p47phox mRNA的表达变化;Western印迹检测p47phox和硝基酪氨酸（NT）的蛋白表达变化。 结果 与NC组大鼠比较,在4、8和12周时,DN大鼠的KI显著增高（P < 0.05）,UAER（mg/24 h）也显著增高（4.92±0.70 比 0.26±0.07、 5.29±0.83 比0.28±0.08、5.54±0.81比0.29±0.04,均P < 0.05）。12周时病理显示DN大鼠肾小球系膜细胞增生,系膜基质积聚;而与DN组大鼠比较,4-PBA治疗组大鼠KI显著降低（P < 0.05）,UAER（mg/24 h）亦显著降低（4、8和12周分别为3.71±0.37、3.47±0.36和3.28±0.40,P < 0.05）,4-PBA能显著减轻肾脏的病理变化。在4、8和12周,与NC组大鼠比较,DN大鼠肾组织p47phox mRNA表达分别升高了154.72%、148.60%和91.95%（均P < 0.05）;p47phox蛋白表达分别升高了118.00%、140.10%和177.82%（均P < 0.05）;硝基酪氨酸蛋白表达分别升高了45.29%、59.13%和89.28%（均P < 0.05）;尿MDA含量分别增加了2.05倍、2.26倍和2.43倍;尿SOD活性分别下降了64.78%、71.29%和79.32%。与DN组比较,在8和12周时,4-PBA治疗组DN大鼠肾组织p47phox mRNA和蛋白表达均显著减少（均P < 0.05）;硝基酪氨酸蛋白表达显著减少（P < 0.05）,且与NC组差异已无统计学意义。另外,在4~12周,4-PBA治疗可显著减少DN大鼠尿中MDA含量,增加尿SOD活性（均P < 0.05）。 结论 4-PBA能显著抑制糖尿病大鼠肾脏病理变化,其机制可能与抑制肾组织氧化应激有关。     

氢气对PC12细胞缺氧复氧时内质网应激的影响

目的 探讨氧气对PC1 2细胞缺氧复氧时内质网应激的影响.方法 PC12细胞采用随机数字表法,将其随机分为4组,正常对照组:细胞常规培养25 h;阳性对照组:细胞正常培养1h后,用氧气饱和的RPM1-1640培养基继续培养24 h;缺氧复氧组:细胞缺氧1h后复氧24 h;氢气组:细胞缺氧1 h后,州氧气饱和的RPM1,1640培氧基复氧24 h.PC12细胞加入含Na2S2O4终浓度为5.0mmol/L的RPMI-1640培养液,5％ CO2培养箱37 ℃孵育1h;更换正常RPMI-1640培养液,继续培养24h,制备PC12细胞缺氧复氧模型.采用WST-1法测定细胞相对增殖率,采用硫代巴比妥酸法测定MDA浓度,采用免疫组化法检测caspase-3表达,采用RT-PCR法检测活化转录因子4(ATF4)mRNA和C/EBP同源蛋白(CHOP)mRNA的表达.结果 与正常对照组和阳性对照组比较,缺氧复氧组细胞相对增殖率降低,MDA浓度升高,caspase-3、ATF4 mRNA和CHOP mRNA的表达七调,氧气组ATF4 mRNA和CHOP mRNA的表达上调(P＜0.05);正常对照组和阳性对照组间细胞相对增殖率、MDA浓度、caspase-3 、ATF4nRNA和CHOP mRNA的表达比较差异无统计学意义(P＞0.05);与缺氧复氧组比较,氢气组细胞相对增殖率升高,MDA浓度降低,caspase-3、ATF4 mRNA和CHOP mRNA的表达下调(P＜0.05).结论 氧气可能通过抑制内质网应激,降低细胞凋亡,减轻PC12细胞缺氧复氧损伤.     

番茄红素对缺氧/复氧诱导小鼠心肌细胞内质网应激和凋亡的影响

目的 评价番茄红素对缺氧/复氧(hypoxia/reoxygenation,H/R)引起的小鼠心肌细胞内质网应激(endoplasmic reticulum stress,ERS)和凋亡的影响. 方法 建立C57BU6乳鼠心肌细胞H/R模型,采用随机数字表法将C57BL/6小鼠心肌细胞分为正常对照组(C组)、番茄红素组(Lyc组,含5μmol/L番茄红素的培养基预处理4h)、H/R组(H/R组,缺氧4h复氧6h)和番茄红素+H/R组(Lyc+H/R组,给予5μmol/L番茄红素预处理4h后行H/R处理).采用水溶性四氮唑-8(cell counting Kit-8,CCK-8)法检测心肌细胞存活率,倒置显微镜下观察细胞搏动频率,TUNEL法检测细胞凋亡率,二氯荧光素法(dichlomnuorescein diacetate,DCFH-DA)检测细胞内活性氧(reactive oxygen species,ROS)含量,实时荧光定量PCR (real-time PCR)检测葡萄糖调节蛋白78(glucose-regulated protein 78,GRP78)、C/EBP同源蛋白(C/EBP homologous protein,CHOP)及半胱天冬氨酸蛋白酶-12 (cysteme aspartate specific protease-12,caspase-12)mRNA的表达,Western blot法分析剪切的半胱天冬氨酸蛋白酶-12(cleaved cysteme aspartate specific protease-12,Cleaved-caspase-12)和剪切的半胱天冬氨酸蛋白酶-3(cleaved cysteme aspartate specific protease-3,Cleaved-caspase-3)的表达. 结果 与C组比较,H/R组心肌细胞存活率显著降低[(100±5)％,(69±6)％](P＜0.01),搏动频率显著降低[(94±6),(28±5)次/min](P＜0.01),心肌细胞凋亡率[(4.9±1.5)％,(25.6±2.6)％]和ROS含量[(100±11)％,(226±10)％]显著升高(P＜0.01);CHOP mRNA[(1.00±0.10)、(2.60±0.19)]和GRP78 mRNA[(1.00±).18)、(4.12±0.23)]表达水平显著升高(P＜0.05);caspase-12 mRNA[(1.00±0.09)、(1.79±0.14)]、Cleaved-caspase-12[(1.00±0.08)、(1.85±0.10)]和Cleaved-caspase-3[(1.00±0.07)、(1.89±0.14)]表达水平显著升高(P＜0.05).与H/R组比较,Lyc+H/R组心肌细胞存活率明显升高[(69±6)％、(84±7)％](P＜0.05),搏动频率增加[(28±5)、(73±6)次/min] (P＜0.05),凋亡率显著降低[(25.6±2.6)％,(18.2±2.2)％](P＜0.05),细胞内ROS含量[(226±10)％、(140±16)％]明显降低,CHOP mRNA [(2.60±0.19)、(1.71±0.14)]和GRP78 mRNA[(4.12±0.23),(1.98±0.19)]表达水平显著降低(P＜O.05);caspase-12 mRNA[(1.79±0.14)、(1.38±0.11)]、Cleaved-caspase-12[(1.85±0.10)、(1.26±0.12)]和Cleaved-caspase-3[(1.89±0.14)、(1.36±0.12)]表达水平显著降低(P＜0.05). 结论 番茄红素可抑制H/R过程中的ERS及其凋亡信号途径而减轻心肌细胞损伤.     

内质网应激反应在严重烧伤大鼠心肌细胞凋亡中的作用

目的内质网应激反应(endoplasmic reticulum stress,ERS)介导的凋亡是真核细胞重要凋亡途径之一,通过观察严重烧伤大鼠心肌ERS不同通路蛋白表达变化,探讨其在心肌细胞凋亡中的可能作用。方法雄性7周龄Wistar大鼠64只,体重200～220 g;随机分为两组,每组32只。实验组大鼠背部制备30%体表面积Ⅲ度烫伤;对照组制备假伤模型。伤后1、4、7、14 d两组各处死8只大鼠取心肌组织,透射电镜观察心肌超微结构变化,TUNEL法检测心肌细胞凋亡,Western blot检测ERS相关蛋白,如葡萄糖调节蛋白78(glucose regulated protein 78,GRP 78)、C/EBP同源蛋白(C/EBP-homologous protein,CHOP)、半胱氨酸天冬氨酸蛋白酶12(Caspase 12)剪切体表达变化。结果大鼠均存活至实验结束。透射电镜观察示实验组大鼠心肌细胞呈凋亡改变。伤后各时间点实验组心肌细胞凋亡指数均明显高于对照组(P<0.05),伤后1、4、7 d凋亡指数逐渐升高,14 d时下降,各时间点间比较差异均有统计学意义(P<0.05)。实验组心肌细胞GRP78、CHOP及Caspase 12剪切体蛋白表达持续升高,其中各时间点GRP 78及Caspase 12剪切体表达均较对照组显著升高,差异有统计学意义(P<0.05);除伤后1 d外,其余各时间点实验组CHOP蛋白表达均较对照组升高(P<0.05)。结论严重烧伤后大鼠心肌发生ERS,其中CHOP、Caspase 12介导的凋亡通路活化,ERS可能是心肌细胞凋亡的途径之一。