1, 25-Dihydroxyvitamin D3 activates Apelin/APJ system and inhibits the production of adhesion molecules and inflammatory mediators in LPS-activated RAW264.7 cells

Background1, 25-Dihydroxyvitamin D3 (1, 25(OH)₂D₃), an active form of vitamin D3, plays a crucial role in the mitigation of inflammation damage. Recent studies have revealed that apelin and its receptor (apelin/APJ system) could significantly ameliorate LPS-induced inflammation-response. This investigation aimed to appraise the effects of 1, 25(OH)₂D₃ on the apelin/APJ system and production of adhesion molecules and inflammatory mediators in LPS–activated RAW264.7 macrophage cells.MethodsMurine RAW264.7 cells were pretreated with 1, 25(OH)₂D₃, followed stimulation with LPS (1 μg/mL) for 24 h. The effect of 1, 25(OH)₂D₃ on LPS-induced cell injury was determined by MTT assay, whereas, enzyme-linked immunosorbent assay (ELISA), qPCR and western blotting were used to evaluate cytokine production and apelin/APJ system expression. Intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) protein expression were measured by flow cytometry.ResultsThe levels of IL-1β, IL-6, and TNF-α cytokines were significantly increased by incubation with LPS. LPS also increased the protein expression of adhesion molecules, including VCAM-1 and ICAM-1. However, pretreatment with 1, 25(OH)₂D₃ markedly inhibited LPS-induced production of inflammatory cytokines and adhesion molecules. Moreover, we found that 1, 25(OH)₂D₃ could induced the apelin/APJ system expression. Further experiments demonstrated the significant increase of apelin/APJ system expression at both the protein and mRNA levels in LPS-activated cells when pretreated with 1, 25(OH)₂D₃.ConclusionTaken together, our results indicated that 1, 25(OH)₂D₃ confers an anti-inflammatory effect through a likely mechanism involving a reduction in pro-inflammatory mediators and adhesion molecules via up-regulation of the apelin/APJ system in RAW264.7 cells.     

2型糖尿病患者血浆apelin水平与血管并发症的相关性分析

目的：探讨2型糖尿病患者血浆 apelin 水平与血管并发症的关系及其可能的影响因素。方法选取2型糖尿病患者60例,其中2型糖尿病无血管并发症（ A）组10例,2型糖尿病合并大血管并发症（B）组12例,2型糖尿病合并微血管并发症（C）组10例,2型糖尿病合并微血管及大血管并发症（D）组28例。健康对照组10例。所有受检者测定血浆apelin,同时检测体重指数（ BMI）、腰臀比（ WHR）、血压（BP）、空腹血糖（FPG）、C肽（C-p）、糖化血红蛋白（HbA1c）、尿微量白蛋白（UAER）、血脂及超声心动图等指标,分析2型糖尿病患者血浆apelin的含量与血管并发症的相关性及其可能影响因素。结果2型糖尿病各组（ A、B、C、D）血浆apelin水平显著高于健康对照组,D组血浆apelin水平显著高于A、B、C组,差异有显著性（P〈0.01）;与血浆apelin水平具有统计学意义的相关性因素有FPG（Beta=0.525,P=0.000）、E/A （Beta=-0.210,P=0.005）、HbA1c（Beta=0.237,P=0.019）、SBP（Beta=0.165,P=0.026）;Logistic回归分析结果显示血浆apelin及总胆固醇（ TC）与2型糖尿病大血管并发症存在相关性,血浆apelin与2型糖尿病微血管并发症存在相关性。结论①2型糖尿病患者血浆apelin水平升高,伴随2型糖尿病血管并发症的发生发展,血浆apelin水平有升高趋势,提示血浆apelin与2型糖尿病及其血管并发症相关;②与血浆apelin水平具有显著性的相关性因素有FPG、E/A、HbA1c、SBP;血浆apelin水平随着FPG、HbA1c及SBP的升高而升高;随着左室舒张功能的下降,血浆apelin水平升高,apelin可能成为预测左室舒张功能不全的指标;③血浆apelin水平升高与2型糖尿病大血管并发症和2型糖尿病微血管并发症存在相关性,血浆apelin水平越高,2型糖尿病血管并发症的发生率越高。     

感染性休克大鼠内源性Apelin及其受体系统表达下调

目的观察内源性Apelin及其受体（血管紧张素受体AT1相关蛋白,APJ）在盲肠结扎和穿孔所致感染性休克大鼠的变化。方法20只雄性Wistar大鼠,体重220～250g,随机分为假手术对照组和晚期休克组。酶联免疫法测定血浆和心肌中Apelin含量,RT-PCR法测定心肌组织Apelin、APJ mRNA水平,Western blot方法测定心肌组织中APJ蛋白水平。结果与假手术组比较,休克组大鼠＋LVdP/dtmax和-LVdP/dtmax明显降低;左心室舒张末期压（LVEDP）增高,平均动脉压降低,心率增快;有严重低血糖症和高乳酸血症。血浆和心肌Apelin含量明显降低（P〈0.01）,心肌组织Apelin、Apelin受体APJ mRNA水平显著下降（P〈0.01）,心肌组织APJ蛋白水平明显降低（P〈0.01）。结论Apelin及其受体系统下调在感染性休克发生发展中可能有重要作用。     

脂肪因子Apelin-13对3T3-L1脂肪细胞水通道蛋白7基因表达的影响

目的 探讨脂肪因子Apelin-13对3T3-L1脂肪细胞水通道蛋白7（AQP7）基因表达的影响.方法 体外培养3T3-L1脂肪细胞,以油红O染色鉴定为成熟脂肪细胞后,分为阴性对照组（无干预）,不同浓度（10^-9、10^-8、10^-7、10^-6nmol/L） Apelin-13干预组（均干预24 h）,阳性对照组（10^-5 nmol/L罗格列酮干预24 h）和10^-7 nmol/L Apelin-13干预不同时间（0、12、24、36、48 h）组.用反转录-聚合酶链反应检测各组细胞AQP7 mRNA表达水平.结果 阴性对照组、10^-9、10^-8、10^-7、10^-6 nmol/L Apelin-13和阳性对照组AQP7表达水平分别为（0.22±0.02）、（0.29±0.07）、（0.36±0.05）、（0.43±0.05）、（0.31±0.06）、（0.32±0.08）,阳性对照组与阴性对照组之间差异有统计学意义（P＜0.05）;与阴性对照组比较,10^-8、10^-7 nmol/L Apelin-13能明显刺激AQP7 mRNA表达（P ＜0.05）;10^-8、10^-7 nmol/L Apelin-13组与阳性对照组比较,10^-7 nmol/L Apelin-13能明显刺激AQP7 mRNA表达（P＜0.05）;10^-8、10^-7 nmol/L Apelin-13组间差异无统计学意义.在时间组中,10^-7 nmol/L Apelin-13的0、12、24、36、48 h各组灰度比值分别为（0.27±0.09）、（0.43±0.07）、（0.55±0.10）、（0.42±0.08）、（0.33±0.09）,12、24、36 h组AQP7 mRNA表达较0h组能明显刺激AQP7 mRNA表达（P＜0.05）,作用24 h表达最高;但12、24、36h3组之间AQP7mRNA表达差异无统计学意义.结论 Apelin-13在一定程度上能增加3T3-L1脂肪细胞AQP7 mRNA表达的水平,并分别以10^-7 nmol/L和24 h为最佳作用浓度和时间.     

严重脓毒症和脓毒症休克患者血浆Apelin水平变化及其意义

目的初步探讨血管活性多肽Apelin在严重脓毒症和脓毒症休克患者中的血浆水平变化及其意义。方法采用酶联免疫分析法测定不同病程观察时间点(诊断当日、诊断第3日、诊断第10日)26例临床诊断严重脓毒症和脓毒症休克患者Apelin水平。结果脓毒症患者Apelin水平较健康对照显著升高(P<0·01);不同病程观察时间点间Apelin水平差异均有显著性(P<0·01);脓毒症休克患者Apelin水平较严重脓毒症患者显著升高(P<0·01)。结论血浆Apelin水平在严重脓毒症和脓毒症休克患者中存在某些变化,可能具有一定的临床意义。     

Apelin/APJ信号在肝硬化及肝癌中的生物作用

Apelin/APJ信号在心脏、血管、脑、肺、胃肠道、肾脏和骨骼肌等多种组织中都有表达,可以参与多种细胞的信号转导过程,所以在调节人体生理和病理生理活动方面可发挥重要的调节作用。Apelin/APJ信号的作用主要包括调节心血管系统的稳态、维持水电解质的平衡、促进垂体激素释放、调节生物节律,还可以作为免疫调节因子对免疫系统进行调节。但是apelin/APJ信号在肝脏疾病中发挥什么样的作用还知之甚少。在肝脏疾病中,apelin/APJ信号可能参与到肝纤维化、肝硬化和肝癌的发生和发展,并且可抑制肝脏的再生。我们对apelin/APJ信号近年来在肝脏方面的研究做一综述。     

ADMA损伤血管内皮后Apelin-13对大鼠血压的影响

目的探讨在非对称性二甲基精氨酸(ADMA)导致大鼠血管内皮损伤的病理条件下,血管活性肽apelin-13对大鼠离体血管产生的效应及对血压的影响。方法成年雄性SD大鼠20只,分为ADMA组和对照组。用微量渗透泵给予两组大鼠分别持续注射ADMA[10 mg/(kg.d)]和生理盐水,28天。基线水平测量大鼠血压。28天后复测血压并检测血清ADMA、一氧化氮(NO)的浓度。给予大鼠尾静脉注射apelin-13(10 nmol/kg),观察血压变化。使用透射电镜观察大鼠尾动脉血管内皮细胞超微结构。行离体尾动脉实验观察apelin-13(10-10～10-5 mol/L)对两组血管环的作用。结果 28天后,ADMA组大鼠血清ADMA浓度明显高于对照组,而NO浓度降低。ADMA组大鼠收缩压较对照组明显升高(154±5 mmHg比123±4 mmHg,P<0.01)。静脉注射apelin-13(10 nmol/kg)后,ADMA组大鼠血压升至159±3 mmHg(P<0.05),而对照组降至113±3 mmHg(P<0.05)。透射电镜下可观察到ADMA组大鼠血管内皮细胞出现变性甚至坏死。离体血管实验表明apelin-13使ADMA组血管收缩而诱发对照组血管环舒张,呈浓度依赖性。结论 ADMA可对血管内皮细胞造成严重损伤,并导致大鼠高血压。在这种病理状态下,apelin-13可促进血管收缩,进而加重大鼠高血压。     

中老年慢性心力衰竭患者血浆Apelin的表达变化及RAS阻滞剂的调控作用

目的 探讨Apelin在中老年慢性心力衰竭（CHF）患者中的表达及RAS阻滞剂的调控作用. 方法 选取处于不同心功能阶段且未经系统治疗的中老年CHF患者186例,根据NYHA心功能分级分为早期组（NYHA分级Ⅰ-Ⅱ级,86例）和晚期组（NYHA分级Ⅲ-Ⅳ级,100例）;每组随机平均分为两个亚组,分别用贝那普利（ACEI类）和缬沙坦（ARB类）治疗;另选30位健康体检人员作为对照组.CHF患者在治疗前及治疗后三个月而对照组在体检时测定血清Apelin 12和Apelin 13水平.CHF患者治疗前测定血脂、血浆N末端脑钠肽前体（NT-pro BNP）、左室舒张末期内径（LVID）及左室射血分数（EF）. 结果 Apelin12、Apelin13在早期组的表达均高于对照组（P均＜0.05）,而在晚期组则均低于对照组（P均＜0.05）.Apelin 12、Apelin 13的表达与EF呈正相关（r=0.252,P＜0.05）,与LVID d、NT-pro BNP呈负相关（r=-0.194,P＜0.05）.晚期组经ARB类药物治疗后三个月Apelin的表达与治疗前比较有明显提高（P均＜0.05）,而ACEI类药物治疗后无明显改变（P均＞0.05）;经ARB/ACEI治疗后,早期组Apelin表达水平与治疗前均无明显变化（P均＞0.05）. 结论 Apelin 12、Apelin 13在中老年CHF患者心衰早期表达升高而晚期下降,而ARB类药物对晚期CHF患者Apelin表达有正性调控作用.     

Apelin-13对ADMA所致内皮细胞骨架损害的影响

目的:探讨Apelin-13对非对称性二甲基精氨酸(asymmetrical dimethyl arginine,ADMA)所致的人脐静脉内皮细胞(human umbilical endothelial cell,HUVEC)细胞骨架损害是否有保护作用及其可能的机制.方法:体外培养HUVEC,根据培养液中加入不同的药物...     

Novel adipokines: links between obesity and atherosclerosis

Today, cardiovascular diseases (CVD) remain the principal cause of death in industrialized countries and are linked to obesity and metabolic syndrome. Metabolic syndrome is characterized by changes in arterial blood pressure, glucose metabolism, lipid and lipoprotein profiles in addition to inflammation. Adipose tissue produces many cytokines and secretory factors termed adipokines. Intra-abdominal (visceral) adipose tissue in particular, rather than peripheral, appears to be associated with global cardiometabolic risk. The present article summarizes information on five recently discovered adipokines: vaspin, visfatin, apelin, acylation stimulating protein (ASP) and retinol-binding protein 4 (RBP4) and their potential beneficial or deleterious roles in obesity and atherosclerosis. Vaspin may have antiatherogenic effects through its potential insulin-sensitizing properties. Similarly, visfatin has been suggested to enhance insulin sensitivity, but its potential role in plaque destabilization may counteract this. Apelin, via inhibition of food intake, and increases in physical activity and body temperature, may promote weight loss, resulting in a beneficial antiatherogenic effect. Further, favourable effects on vasodilatation and blood pressure add to this positive effect. Considering its increased levels in subjects with demonstrated atherosclerosis, RBP4 may constitute a biomarker. Lastly, ASP, often increased in obesity and metabolic disorders, may be contributing to efficient lipid storage, and decreasing or blocking ASP may provide a potential antiobesity target. Adipokines may further contribute to obesity-atherosclerosis relationships, the full understanding of which will require further research.