脂质运载蛋白-2在川崎病相关心肌损伤中的作用及机制研究

目的 探讨川崎病（KD）相关心肌损伤的可能机制。 方法 将45只（1月龄）SD大鼠随机分为对照组、干酪乳杆菌细胞壁成分(LCWE)模型组和4-苯基丁酸（4-PBA）治疗组。建立大鼠川崎病模型4周后，用酶联免疫吸附剂测定法ELISA检测KD大鼠血浆和心肌组织匀浆中脂质运载蛋白（Lcn）2的含量；超声心动图检测大鼠心脏功能；各组大鼠心肌组织制作石蜡切片并进行细胞凋亡TUNEL染色；蛋白质印迹法（Western blot）检测大鼠心肌内质网应激的标志物表达变化。离体实验采用原代培养新生大鼠心肌细胞，Lcn 2处理48 h后检测细胞活力、半胱氨酸天冬氨酸蛋白酶（Caspase）3活性以及内质网应激程度。 结果 与对照组比较，KD大鼠血浆和心肌组织匀浆中Lcn 2的含量显著升高（P<0.05）。用Lcn 2（10 ng/ml）处理原代培养的心肌细胞48 h后可导致心肌细胞活力显著降低（P<0.05），同时标志物活化转录因子（ATF）6、CCAAT/增强子结合蛋白同源蛋白（CHOP）、磷酸化的蛋白激酶R样内质网激酶（p-PERK）、磷酸化的真核起始因子（p-elF）2α均出现升高，导致凋亡信号Caspase 12和活化的Caspase（cleave-Caspase）3水平显著增高（P<0.05）。KD大鼠心肌出现促凋亡性内质网应激，ATF6、CHOP、p-PERK、p-elF2α均显著升高，导致凋亡信号Caspase 12和cleave-Caspase 3水平显著增高（P<0.05）。同时伴有左室舒张末期内径（LVIDd）显著增加（P<0.05），左室射血分数（LVEF）显著降低（P<0.05）。使用4-PBA后能够有效抑制KD状态下的心肌内质网应激程度，降低ATF6、CHOP、p-PERK、p-elF2α水平，降低Caspase 12和cleave-Caspase 3水平（P<0.05），同时有效提升LVEF（P<0.05），改善KD大鼠心脏泵血功能，减少LVIDd（P<0.05），并最终改善KD大鼠舒张功能。 结论 KD诱发心脏收缩舒张功能障碍同时伴有Lcn 2 显著升高。Lcn 2对心肌细胞的直接作用是促凋亡性内质网应激。抑制KD状态下的心肌内质网应激可抑制心肌凋亡改善心脏功能。      

脂质运载蛋白2在肝脏疾病发生发展中的作用

脂质运载蛋白2(LCN2)最初是从感染猴空泡病毒40的小鼠肾细胞培养物中纯化得到的一种分泌糖蛋白,在炎症期间对细胞稳态控制以及应对细胞应激或损伤的反应中发挥着关键作用,被认为是风湿病、癌症、肝脏疾病和炎症性疾病的一种潜在的生物标志物。已有研究表明,LCN2在肝实质细胞和非实质细胞中表达并分泌入血,与急性肝损伤、肝硬化、病毒性肝炎、酒精性肝病、非酒精性脂肪性肝病以及肝细胞癌等的发生发展密切相关。本文总结了LCN2与肝脏疾病发病机制相关的动物实验和临床研究,以期为肝脏疾病的防治提供新思路和治疗靶点。     

成骨细胞分泌的新型厌食因子:脂质运载蛋白2

骨骼作为一种全新的内分泌器官,通过自分泌、旁分泌或远距分泌活性因子参与糖脂代谢、骨代谢、细胞增殖及认知等生命活动。最新研究发现,成骨细胞分泌脂质运载蛋白2 (lipocalin-2,LCN2)穿过血脑屏障,参与下丘脑LCN2-黑素皮质素受体-4 (melanocortin receptor-4,MC4R)-环磷酸腺苷(cyclic adenosine monophosphate,c AMP)食欲调控通道以抑制食欲,进而影响能量代谢,但其作用机制尚未明确。既往研究发现,LCN2可在许多组织中表达,参与炎症、免疫调节、肿瘤及心血管疾病等多种生理病理活动。本文主要以LCN2相关文献为理论基础,整理归纳成骨细胞分泌LCN2的功能及作用机制,为肥胖症机制提供新的视角。     

白藜芦醇激活Sirt1/Nrf2信号减轻川崎病诱发的心肌损伤

目的 探讨白藜芦醇在川崎病（KD）诱发心肌损伤中的作用及对Sirt1/Nrf2信号通路的调控。 方法 60只4周龄SD大鼠随机分为对照（Control）组、干酪乳杆菌细胞壁成分（LCWE）模拟川崎病（KD）组、白藜芦醇干预KD（KD + Res）组和白藜芦醇联合Sirt1抑制剂EX527干预KD（KD+Res+EX527）组,对照组腹腔注射生理盐水0.5 ml,其余各组腹腔注射LCWE 0.5 ml（1 mg/ml）,此外,KD+Res组腹腔注射Res（100 mg/kg）,KD+Res+EX527组腹腔注射Res（100 mg/kg）和EX527（5 mg/kg）。4周后,小动物超声检测大鼠心脏功能,酶联免疫吸附法（ELISA）检测心肌组织内丙二醛（MDA）含量、超氧化物歧化酶（SOD）和Caspase-3的活性,Western blot检测心肌组织内沉默信息调节因子（Sirt）1、核因子E2相关因子（Nrf）2和血红素加氧酶（HO）-1以及凋亡相关蛋白Bcl2和Bax的蛋白表达水平。 结果 与对照组相比,KD组左室射血分数（EF）和短轴缩短率（FS）均明显降低（P < 0.05）,心肌组织凋亡相关蛋白Bcl2与Bax比值显著降低（P < 0.05）,Caspase-3活性明显升高（P < 0.05）,心肌组织中MDA含量增加,而SOD活性降低（P < 0.05）,Sirt1、Nrf2和HO-1蛋白表达均显著降低（P < 0.05）;而应用Res后,可显著改善KD引起的心肌损伤,明显降低心肌组织氧化应激程度（P < 0.05）,并伴有Sirt1、Nrf2和HO-1蛋白表达的升高（P < 0.05）。而Sirt1抑制剂EX527可阻断白藜芦醇的保护作用。 结论 KD引起的心肌损伤中Sirt1/Nrf2信号通路抑制,氧化应激增强;而Res可通过激活Sirt1/Nrf2信号减轻氧化应激改善KD引起的心肌损伤。     

脂质运载蛋白2在心血管疾病中的研究进展

脂质运载蛋白2(LCN2)属于人脂质运载蛋白家族,可直接参与冠状动脉粥样硬化性心脏病、高血压、心力衰竭、动脉瘤等心血管疾病的发生发展,并预测预后,有望成为评估心血管疾病严重程度、判断预后的生物标志物和治疗心血管疾病的新靶点。     

延边地区朝鲜族和汉族中老年人群中脂质运载蛋白2与非酒精性脂肪肝的相关性

目的 探讨延边地区朝鲜族和汉族中老年人群中脂质运载蛋白(LCN)2与非酒精性脂肪肝(NAFLD)的相关性.方法 2017年6～12月在参与慢性健康体检的45岁及以上成年人1226名,测定身高、体重、血脂、血糖、肾功、肝功和LCN2等指标,分析LCN2与NAFLD的相关性及NAFLD的影响因素.结果 朝鲜族中NAFLD组...     

核因子E2相关因子2/血红素加氧酶-1信号在川崎病诱发心肌损伤中的作用

目的 探讨核因子E2相关因子（Nrf）2/血红素加氧酶（HO）-1信号通路在川崎病（KD）诱发心肌损伤中的作用。 方法 60只4周龄SD大鼠随机分为对照组、干酪乳杆菌细胞壁成分（LCWE）模拟川崎病组（KD）和叔丁基对苯二酚（TBHQ）干预KD组（KD+TBHQ）,每组20只;对照组腹腔注射生理盐水0.5 ml,KD组和KD+TBHQ组腹腔注射LCWE 0.5 ml（1 mg/ml）。4周后,小动物超声检测大鼠心脏功能,酶联免疫吸附法（ELISA）检测心肌组织内丙二醛（MDA）含量、超氧化物歧化酶（SOD）和Caspase-3的活性,Western blot检测心肌组织内Nrf2和HO-1以及凋亡相关蛋白Bcl-2和Bax的蛋白表达水平。 结果 注射LCWE 4周后,成功制备KD模型鼠。同时发现,与对照组相比,KD组左室射血分数（LVEF）和短轴缩短率（FS）均明显降低（P < 0.05）,心肌组织凋亡相关蛋白Bcl-2与Bax比值显著降低（P < 0.05）,Caspase-3活性明显升高（P < 0.05）,心肌组织中MDA含量增加,而SOD活性降低（P < 0.05）,Nrf2和HO-1蛋白表达显著降低（P < 0.05）;而应用Nrf2激动剂TBHQ后,可显著改善KD引起的心肌损伤,并且明显降低心肌组织氧化应激程度（P < 0.05）。 结论 KD抑制心肌中Nrf2/HO-1信号,导致氧化应激程度增强,引起细胞凋亡增加,进而引发心脏损伤,TBHQ激活Nrf2可明显改善KD的上述作用。     

川崎病冠状动脉损伤患儿血清可溶性人基质裂解素2的浓度及临床意义

目的 探讨川崎病（Kawasaki disease,KD）冠状动脉损伤（coronary artery lesion,CAL）患儿血清可溶性人基质裂解素2(soluble suppression of tumorigenicity-2,ST2)的浓度及临床意义。方法 回顾性分析自贡市第四人民医院2018年10月至2019年12月的155例川崎病患儿的临床资料,分为CAL组（n=56）和无CAL组（n=99）;另选取健康儿童30名为对照组。比较3组研究对象血清sST2浓度及常规实验指标如C反应蛋白（C-reactive protein,CRP）浓度、白细胞（white blood cell,WBC）计数、红细胞沉降率（erythrocyte sedimentation rate,ESR）、白蛋白浓度、血小板计数等资料的差异。结果 与对照组比较,NCA组和CAL组患者血清sST2、CRP浓度及WBC计数、ESR均显著增高,而血清白蛋白浓度、血小板计数均显著降低,差异有统计学意义（P<0.05）;非CAL组与CAL组患儿上述指标比较,差异均有统计学意义（P<0.05）。Logis...     

姜黄素对脂质运载蛋白2诱导人脐静脉内皮细胞损伤的影响

目的研究姜黄素对脂质运载蛋白2(LCN-2)诱导人脐静脉内皮细胞(HUVEC)损伤的保护作用及与p38 MAPK通路的关系。方法以LCN-2不同质量浓度(0,5,10,20μmol/L)及不同时间(0,24,48,72 h)作用HUVEC,CCK-8法测细胞增殖,流式细胞仪测细胞凋亡,ELISA测细胞上清液中单核细胞趋化蛋白1(MCP-1)及白细胞介素6(IL-6)含量,比色法测乳酸脱氢酶(LDH)活性,Western blot测HUVEC中p-p38 MAPK、Bax、Bcl-2蛋白表达;分别加入10μmol/L姜黄素和25μmol/L SB203580观察姜黄素的干预作用。结果与对照组比较,LCN-2可显著抑制HUVEC增殖,上调HUVEC内Bax/Bcl-2蛋白比率而促进细胞凋亡,诱导HUVEC分泌MCP-1及IL-6,增加LDH活性(P0.05);与LCN-2组比较,姜黄素及SB203580均可显著减轻LCN-2诱导的HUVEC增殖抑制,下调Bax/Bcl-2蛋白比率而抑制HUVEC凋亡,减少LCN-2诱导的HUVEC分泌MCP-1及IL-6,降低LDH活性(P0.05)。结论姜黄素可通过抑制p38 MAPK通路,减轻LCN-2诱导的HUVEC损伤。     

川崎病致肺动脉内皮损伤和肺动脉高压的实验研究

目的 探讨川崎病(KD)对肺血管内皮功能的影响以及与肺动脉高压发生的相关性。方法 采用干酪乳杆菌细胞壁成分(LCWE)建立川崎病大鼠模型,将40只(1月龄)SD大鼠随机分为对照组和KD组,KD组大鼠腹腔注射LCWE 0.5 ml(1 mg/ml)来建造KD模型。造模2周后采用组织病理学评估冠状动脉和肺动脉的损伤情况。测定大鼠体循环压力、右心室压力和右心室肥厚指数、肺小动脉舒张功能。检测肺小动脉组织抗氧化酶锰超氧化物歧化酶(MnSOD)和过氧化氢酶(Catalase)的表达水平,以及氧化应激水平。结果 LCWE注射14 d后,与对照组比较,成功诱导KD大鼠冠状动脉损伤(P<0.05),KD组大鼠出现肺组织损伤,肺组织水肿,点、片状出血,伴中性粒细胞为主的炎性细胞浸润。肺小动脉内皮细胞肿胀,中膜层出现不规则间断性肥厚,管腔呈部分狭窄,肺动脉损伤评分升高(P<0.05)。肺小动脉组织MnSOD和Catalase的表达水平较对照组显著降低(P<0.05),髓过氧化物酶(MPO)、丙二醛(MDA)水平明显升高(P<0.05)。同时,KD组大鼠右心室压力和肥厚指数较对照组明显升高(P<0.05),离体血管灌流实验证实,KD组大鼠肺小动脉内皮依赖性的舒张作用明显减弱(P<0.01)。结论 KD可导致肺小动脉血管炎,引发肺小动脉血管内皮损伤和氧化应激损伤,可能是诱发肺动脉高压和继发性心脏损伤的重要原因之一。     

HIP-55介导血管紧张素Ⅱ诱导的血管胶原沉积

目的探究HIP-55是否介导血管紧张素Ⅱ诱导的血管胶原沉积。方法生物信息学分析的方法预测HIP-55是否参与血管紧张素Ⅱ(AngⅡ)诱导的血管重构,小鼠背部皮下埋入AngⅡ(1 mg·kg~(-1)·d~(-1))微量泵14 d诱导血管重构模型,利用无创血压仪检测小鼠血压变化,蛋白质印迹法(Western blot)、反转录聚合酶链式反应(RT-PCR)检测HIP-55在血管重构模型中的表达变化情况。并构建HIP-55基因敲除小鼠,将小鼠分为4组:野生/假手术组(WT/Sham组)、HIP-55基因敲除/假手术组(HIP-55~(-/-)/Sham组)、野生/埋泵组(WT/AngⅡ组)和HIP-55基因敲除/埋泵组(HIP-55~(-/-)/AngⅡ组),主动脉苏木素-伊红(HE)染色,Masson染色检测血管形态变化及胶原沉积变化。结果生物信息学提示HIP-55可能参与AngⅡ诱导的血管重构。与对照组相比,实验组小鼠血管胶原沉积显著增加(3.1±0.18比1.1±0.04,P<0.01)、血管横切平均面积显著增加(2.7±0.1比1.0±0.04,P<0.01)、平均厚度明显增加[(105.7±7.0)μm比(66.0±7.6)μm,P<0.01]、平均厚度/内径明显增加(0.28±0.01比0.17±0.01,P<0.01)。实验组小鼠血管中HIP-55 mRNA(1.6±0.22比1.0±0.03,P<0.01)和HIP-55蛋白(1.6±0.15比1.0±0.04,P<0.01)表达水平均明显增加。与WT/Sham组相比,HIP-55~(-/-)/Sham组小鼠的血管胶原沉积水平无明显变化(1.1±0.04比1.0±0.05,P=0.70);给予AngⅡ埋泵后,与WT/AngⅡ组相比,HIP-55~(-/-)/AngⅡ组小鼠的血管胶原沉积明显减少(2.6±0.2比3.3±0.1,P<0.05)。结论 HIP-55介导AngⅡ诱导的血管胶原沉积。     

sST2参与急性心肌梗死后心肌纤维化

目的探索可溶性生长刺激表达基因2(sST2)与急性心肌梗死(AMI)后心肌纤维化的关系。方法入选2015年1月至2016年9月入住兰州大学第一医院心脏中心的患者249例,AMI组为首次诊断AMI的166例患者,对照组为冠状动脉造影阴性的83例患者。测定患者血清sST2、Ⅲ型前胶原氨基端肽(PⅢNP)及N末端B型利钠肽原(NT-pro BNP)水平,并收集心脏超声中与左心室收缩功能相关的指标:左心室射血分数(LVEF)、左心室收缩期末容积(LVESV)、左心室舒张期末容积(LVEDV),并进行比较、分析。结果 AMI组血清sST2、PⅢNP、NTpro BNP水平及LVESV、LVEDV值均高于对照组,LVEF值明显低于对照组(P0.05或P0.01)。AMI组中,LVEF50%亚组血清sST2水平高于LVEF≥50%亚组(P=0.031)。AMI组中血清sST2与PⅢNP呈正相关(r=0.181,P=0.02),与LVEF呈负相关(r=-0.179,P=0.021)。AMI组中血清sST2、NT-pro BNP及sST2+NT-pro BNP诊断AMI后心力衰竭的ROC曲线下面积分别为0.608、0.683和0.732。结论血清sST2参与AMI后心肌纤维化过程,并与左心室收缩功能有关。血清sST2水平对AMI后心力衰竭具有诊断价值。     

Enhanced deposition of predominantly type I collagen in myocardial disease

The myocardium consists of a muscle fibre array surrounded and interspersed by a network of connective tissue, principally collagen, which maintains the functional integrity of the heart. Changes in collagen composition may therefore contribute to altered ventricular function. Collagen composition was examined in cardiac tissue from 15 patients undergoing orthotopic cardiac transplantation. Of these, 10 had severely impaired left ventricular function due to coronary artery disease. The remaining five had dilated cardiomyopathy. Normal heart tissue was taken at autopsy from 25 patients who died of causes unrelated to cardiovascular disease. Left ventricular collagen concentration, estimated from hydroxyproline levels, increased from 48.6 +/- 4.1 mg/g dry weight of tissue in the control group to 95.3 +/- 9.7 mg/g (P less than 0.01) in patients with dilated cardiomyopathy and to 63.5 +/- 9.8 mg/g in the coronary artery disease group. This increase was attributable to an increase in absolute concentrations of both type I and III collagen, determined by separation of cyanogen bromide peptides by sodium dodecyl sulphate polyacrylamide gel electrophoresis. However, there was a significant decrease in the proportion of type III collagen (compared with type I plus III) from 41.8 +/- 1.1% in controls, to 34.6 +/- 1.5% (P less than 0.01) in the coronary artery disease group and 35.8 +/- 2.8% (P less than 0.05) in the dilated cardiomyopathy group. These results suggest that excessive collagen production, with a preponderance of type I, occurs in these forms of myocardial disease, indicative of a remodelling of the collagen matrix, which, by increasing passive myocardial stiffness may contribute to impaired heart function seen in these groups of patients.     

Increased collagen turnover is only partly associated with collagen fiber deposition in the arterial response to injury

OBJECTIVE: In the arterial response to injury, collagen breakdown has been studied extensively, but little is known on collagen synthesis and fiber formation. Here, we studied in vivo collagen synthesis and collagen fiber content in relation to collagen breakdown following arterial balloon injury. METHODS AND RESULTS: Twenty-five New Zealand White rabbits were balloon dilated in femoral and iliac arteries and terminated at 2, 7, 14 and 28 days. From day 7, both constrictive arterial remodeling and intimal hyperplasia were observed. Collagen degradation, synthesis and fiber content were studied using zymography, quantitative Polymerase Chain Reaction, Western blotting and picrosirius red staining. Collagen synthesis, reflected by procollagen I and heat shock protein 47 (Hsp47) expression, increased at day 2 with a maximum at day 14 and was accompanied by increased collagen breakdown as reflected by matrix metalloproteinase-1 and -2 levels. Collagen content in media and adventitia only increased between days 2 and 7 after balloon injury. CONCLUSIONS: In the first week after arterial injury, increased collagen content is associated with increased collagen synthesis and degradation. However, after 1 week, collagen turnover remains high in contrast to increased collagen fiber content. This suggests that after 1 week, collagen turnover is used for other processes like cell migration and arterial remodeling.     

Ca2+ -induced cell injury of cardiomyocyte

Pathogenesis of ischemia/reperfusion injury involves Ca(2+) -induced cell injury. Elevated intracellular Ca(2+) concentration at the reperfusion activates the Ca(2+) dependent protease, calpain and increases the generation of reactive oxygen species (ROS) in mitochondria, which cause cell injury in ischemia/reperfusion.     

Exaggerated left ventricular dilation and reduced collagen deposition after myocardial infarction in mice lacking osteopontin

Osteopontin (OPN), an extracellular matrix protein, is expressed in the myocardium with hypertrophy and failure. We tested the hypothesis that OPN plays a role in left ventricular (LV) remodeling after myocardial infarction (MI). Accordingly, OPN expression and LV structural and functional remodeling were determined in wild-type (WT) and OPN knockout (KO) mice 4 weeks after MI. Northern analysis showed increased OPN expression in the infarcted region, peaking 3 days after MI and gradually decreasing over the next 28 days. In the remote LV, OPN expression was biphasic, with peaks at 3 and 28 days. In situ hybridization and immunohistochemical analyses showed increased OPN mRNA and protein primarily in the interstitium. Infarct size, heart weight, and survival were similar in KO and WT mice after MI (P=NS), whereas the lung wet weight/dry weight ratio was increased in the KO mice (P<0.005 versus sham-operated mice). Peak LV developed pressure was reduced to a similar degree after MI in the KO and WT mice. The number of terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL)-positive myocytes was similar in KO and WT mice after MI. In contrast, post-MI LV chamber dilation was approximately twice as great in KO versus WT mice (P<0.001). Myocyte length increased after MI in WT mice (P<0.001) but not in KO mice. Electron microscopy showed increased collagen content in WT mice after MI but not in KO mice after MI. Type I collagen content was increased approximately 3-fold and approximately 7-fold in remote and infarcted regions, respectively, of WT hearts after MI but not in KO hearts (P<0.01 versus WT hearts). Likewise, Northern analyses showed increased collagen I(alpha(1)) mRNA after MI in remote regions of WT hearts but not in KO hearts. Thus, increased OPN expression plays an important role in regulating post-MI LV remodeling, at least in part, by promoting collagen synthesis and accumulation.