Association of RAGE gene polymorphism with circulating AGEs level and paraoxonase activity in relation to macro-vascular complications in Indian type 2 diabetes mellitus patients

Background and aims

Sustained interaction of advanced glycation end products (AGEs) with their receptor RAGE and subsequent signaling plays an important role in the development of diabetic complications. Genetic variation of RAGE gene may be associated with the development of vascular complications in type 2 diabetes mellitus (T2DM).

Objectives

The present study aimed to explore the possible association of RAGE gene polymorphisms namely − 374T/A, − 429T/C and G82S with serum level of AGEs, paraoxonase (PON1) activity and macro-vascular complications (MVC) in Indian type 2 diabetes mellitus patients (T2DM).

Methods

A total of 265 diabetic patients, including DM without any complications (n = 135), DM-MVC (n = 130) and 171 healthy individuals were enrolled. Genotyping of RAGE variants were assessed by polymerase chain reaction-restriction fragment length polymorphism. Serum AGEs were estimated by ELISA and fluorometrically. and PON1 activity was assessed spectrophotometrically.

Results

Of the three examined SNPs, association of − 429T/C polymorphism with MVC in T2DM was observed (OR = 3.001, p = 0.001) in the dominant model. Allele ‘A’ of − 374T/A polymorphism seems to confer better cardiac outcome in T2DM. Patients carrying C allele (− 429T/C) and S allele (G82S) had significantly higher AGEs levels. − 429T/C polymorphism was also found to be associated with low PON1 activity. Interaction analysis revealed that the risk of development of MVC was higher in T2DM patients carrying both a CC genotype of − 429T/C polymorphism and a higher level of AGEs (OR = 1.343, p = 0.040).

Conclusion

RAGE gene polymorphism has a significant effect on AGEs level and PON1 activity in diabetic subjects compared to healthy individuals. Diabetic patients with a CC genotype of − 429T/C are prone to develop MVC, more so if AGEs levels are high and PON1 activity is low.     

Allele-specific targeting of hsa-miR-657 to human IGF2R creates a potential mechanism underlying the association of ACAA-insertion/deletion polymorphism with type 2 diabetes

The biological mechanism of a recent discovered association of type 2 diabetes with the ACAA-insertion/deletion polymorphism at the 3′UTR of the IGF2R gene has remained unclear. A very recently emerging novel polymorphic control layer by microRNAs (miRNAs) makes it possible to elucidate this issue. In this study, a prediction by web tools MicroInspector and miRanda demonstrated that DNA sequence polymorphism (DSPs) ACAA-insertion/deletion in IGF2R 3′UTR is located within the hsa-miR-657 and hsa-miR-453 binding sites. And luciferase reporter assay revealed that hsa-miR-657 acts directly at the 3′UTR of the IGF2R. Furthermore, ACAA-deletion exerted a further repression compared with ACAA-insertion, indicating that hsa-miR-657 regulates IGF2R gene expression in a polymorphic control manner. Importantly, we also demonstrated that hsa-miR-657 can translationally regulate the IGF2R expression levels in Hep G2 cells. Thus, our findings testify the possibility that the ACAA-insertion/deletion polymorphism may result in the change of IGF2R expression levels at least in part by hsa-miR-657-mediated regulation, contributing to the elucidation for the pathogenesis of type 2 diabetes and raise the possibility that miRNAs or in combination with functional DNA sequence polymorphism may be valuable in the treatment of human type 2 diabetes.     

糖尿病肝脏基因表达谱代谢学分析

目的:探讨糖尿病患者肝脏与正常对照肝脏基因表达谱的变化,并进行代谢通路生物信息学分析.方法:应用Affymetrix的Human Genome U133A array芯片检测糖尿病肝脏组织(n=2)和正常对照肝脏组织(n=2)的基因表达谱变化,通过DAVID分析平台对芯片监测到的表达上调的基因进行KEGG通路分析,并用RT-PCR验证部分基因的表达情况.结果:以比值大于2或小于-2为准,共有492条基因明显上调,820条基因明显下调;在差异表达明显的前20位基因中,涉及氧化应激、免疫炎症反应和脂代谢.KEC-G代谢通路分析显示:该差异表达基因谱符合2型糖尿病的发病机制,其差异表达明显基因的代谢通路涉及胰岛素信号通路、脂代谢、补体和凝血系统、糖代谢、粘附功能和细胞因子和受体的相互作用.RT-PCR证实差异表达明显基因SOD2mRNA和CRPmRNA确实表达明显上调.结论:糖尿病肝脏与正常肝脏组织基因表达谱的变化在代谢通路上主要表现为在糖、脂代谢和胰岛素信号通路、补体和凝血系统等的改变,肝脏在糖尿病发病机制中的作用可能与其参与糖脂代谢和胰岛素的作用异常有关.     

Effects of diabetes and insulin on ketone bodies metabolism in heart

This work investigates the effect of alloxan-induced short-term diabetes (24 h) on D-3-hydroxybutyrate metabolism at physiological and non-physiological concentrations of the ketone body in the isolated non-working perfused rat heart. Also the effect of insulin (2 mU.ml⁻¹) on D-3-hydroxybutyrate metabolism was investigated in hearts from normal and diabetic rats. The rates of D-3-hydroxybutyrate utilization and oxidation and of acetoacetate production were proportional to D-3-hydroxybutyrate concentration. The utilization of D-3-hydroxybutyrate showed saturation kinetics in hearts from normal and diabetic rats, in the presence and absence of insulin. Acute short-term diabetes augmented D-3-hydroxybutyrate utilization and oxidation at 1.25 and 2.5 mM DL-3-HB, with no significant effect at higher concentrations, but increased acetoacetate production at all investigated concentrations. In hearts from normal rats, insulin enhanced D-3-hydroxybutyrate utilization and oxidation at 2.5, 5, and 10 mM DL-3-HB, but no effect was observed at the lowest (1.25 mM) and highest (16 mM) DL-3-HB concentrations. Insulin had no effect on D-3-hydroxybutyrate metabolism in hearts from diabetic rats. No significant effect of insulin on the rate of acetoacetate production in normal and diabetic states was observed.     

利拉鲁肽联合达格列净对超重或肥胖2型糖尿病患者肾功能、氧化应激以及内脏脂肪含量的影响

摘要 目的：探讨利拉鲁肽联合达格列净对超重或肥胖2型糖尿病（T2DM）患者肾功能、氧化应激以及内脏脂肪含量的影响。方法：选取我院于2018年1月~2020年5月期间接收的108例超重或肥胖T2DM患者,按照随机数字表法分为对照组（n=54）和观察组（n=54）。对照组给予利拉鲁肽治疗,观察组给予利拉鲁肽联合达格列净治疗,均治疗12周。对比两组肾功能[血胱抑素 C（CysC）、血肌酐（Scr）、血尿酸（SUA）]、氧化应激[丙二醛（MDA）、谷胱甘肽过氧化物酶（GSH-PX）、超氧化物歧化酶（SOD）]、体质量指数（BMI）、腰围、血糖指标[空腹血糖（FBG）、餐后2 h血糖（2hPBG）、糖化血红蛋白（HbA1c）]以及体成分指标（全身脂肪百分比、内脏脂肪含量）,记录两组治疗期间不良反应情况。结果：两组治疗后BMI、腰围、2hPBG、FBG、HbA1c均下降,且观察组较对照组低（P<0.05）。两组治疗后MDA均下降,且观察组较对照组低（P<0.05）,两组治疗后SOD、GSH-PX均升高,且观察组较对照组高（P<0.05）。两组治疗后全身脂肪百分比、内脏脂肪含量均下降,且观察组较对照组低（P<0.05）。两组治疗前后CysC、Scr、SUA组内及组间对比均无统计学差异（P>0.05）。两组不良反应发生率对比无统计学差异（P>0.05）。结论：超重或肥胖T2DM患者利拉鲁肽治疗基础上联合达格列净,降糖效果确切,减轻机体氧化应激,降低内脏脂肪含量,对肾功能无显著影响,且不增加不良反应发生率。     

2型糖尿病患者醛糖还原酶基因5′调控区的多态性与功能

 为了探讨醛糖还原酶基因 5′调控区存在的可引起蛋白质表达发生改变的遗传变异及这些变异与糖尿病视网膜病变的相关性 ,应用PCR SSCP分析对醛糖还原酶基因 5′调控区 - 60 9～ + 4 0的DNA片段进行了筛选 .所有变异体均进行DNA序列分析并克隆至氯霉素乙酰转移酶报告基因载体(pCATreportervector) ,然后将重组质粒转染HeLa细胞 ,通过检测氯霉素乙酰转移酶的活性求出启动子的相对活性 .同时进行凝胶滞留试验与足纹分析以确定DNA与核蛋白的相互作用 .结果显示 ,在 1 45名 2型糖尿病患者及 1 2 3名正常对照的醛糖还原酶基因 5′调控区除野生型外 ,共发现 2种多态性 [C( - 1 0 6)T、C( - 1 2 )G].在正常对照与患者中 ,基因型WT WT ,WT C( - 1 2 )G和WT C( - 1 0 6)T的发生率无显著性差异 .在有视网膜并发症与无视网膜并发症的 2型糖尿病患者中 ,WT C( -1 0 6)T的发生率分别为 35 5%和 1 7 9% ( χ2 =4 0 0 ,P <0 0 5) ,WT C( - 1 2 )G的发生率分别为1 5 5%和 3 3% ( χ2 =3 43,P >0 0 5) .在有并发症的患者中 ,WT C( - 1 2 )G和WT C( - 1 0 6)T两者的总发生率为 42 3% ,显著高于无并发症的患者 ( 2 0 0 % ) ( χ2 =6 2 3,P <0 0 2 5) .野生型 ,C( - 1 2 )G和C( - 1 0 6)T等 3种调控序列的相对活性分别为     

Effect of end-stage renal disease and diabetes on zinc and copper status

The aim of this study was to compare the nutritional status of zinc and copper in patients with and without diabetes submitted to chronic hemodialysis. Thirty-three patients with type 2 diabetes (DM group), 30 nondiabetic patients (NDM group), and 20 healthy individuals (control group) were studied. Plasma, erythrocyte, and urinary zinc and plasma copper were obtained from atomic absorption spectrophotometry and ceruloplasmin by immunonephelometry. The anthropometric parameters were similar among the groups. Plasma zinc was lower and erythrocyte zinc was higher in the DM and NDM groups in relation to the control group. No difference in urinary zinc was observed comparing the groups. Plasma copper was higher in the DM group when compared to the NDM and control groups. Ceruloplasmin was similar in the three groups. Serum urea was a positive independent determinant of plasma zinc concentrations. The determinants of erythrocyte zinc were MAMC midarm nuscle circumference and Kt/V dialysis adequacy. The determinants of plasma copper concentration were serum creatinine and serum glucose. The results of this study demonstrate an alteration in the distribution of zinc of patients with chronic kidney disease (CKD) independently of the presence of DM. Also, the status of copper seems not to be influenced by CKD, but only by the metabolic derangements associated with diabetes.     

孕妇肠道微生物组成与孕妇及新生儿糖脂代谢相关性研究

目的研究孕妇肠道微生物组成与孕妇以及新生儿糖脂代谢的相关性。方法选择2017年6月至2018年9月在大连市妇幼保健院定期产检的诊断为妊娠期糖尿病(GDM)的孕妇89例为GDM组,血糖正常孕妇96例为对照组。收集孕妇一般资料,孕妇和新生儿糖脂代谢物、孕妇粪便进行微生物检测。结果 GDM组孕妇空腹血糖、甘油三酯明显高于对照组,高密度脂蛋白水平明显低于对照组(均P<0.05)。GDM新生儿脂联素和血糖明显低于对照组,胰岛素和糖化血红蛋白明显高于对照组(均P<0.05)。对照组孕妇肠道微生物中拟杆菌(Bacteroides)丰富度最高(36.6%),其次是普雷沃菌(Prevotella)(15.3%)、柔嫩梭菌(Faecalibacterium)(10.2%)、考拉杆菌(Phascolarctobacterium)(7.2%)。GDM组孕妇肠道微生物中拟杆菌(Bacteroides)丰富度最高(29.4%),其次是柔嫩梭菌(Faecalibacterium)(19.7%)、普雷沃菌(Prevotella)(11.1%)、考拉杆菌(Phascolarctobacterium)(9.3%)。柔嫩梭菌(Faecalibacterium)与孕妇空腹血糖呈正相关(r=0.377 6,P=0.027 6),拟杆菌(Bacteroides)、埃希菌(Escherichia)与孕妇甘油三酯呈负相关(r=-0.027 5,-0.585 8,P=0.023 7,0.041 3)。柔嫩梭菌(Faecalibacterium)与新生儿空腹血糖呈负相关(r=-0.397 6,P=0.027 6)。结论 GDM孕妇肠道微生物构成与血糖正常孕妇不同,菌群丰富度和多样性较低,并且孕妇肠道菌群与其及新生儿的糖脂代谢相关,调节孕妇肠道菌群或有利于改善其与新生儿的糖脂代谢功能。     

Matriptase-2- and proprotein convertase-cleaved forms of hemojuvelin have different roles in the down-regulation of hepcidin expression

Hemojuvelin (HJV) is an important regulator of iron metabolism. Membrane-anchored HJV up-regulates expression of the iron regulatory hormone, hepcidin, through the bone morphogenic protein (BMP) signaling pathway by acting as a BMP co-receptor. HJV can be cleaved by the furin family of proprotein convertases, which releases a soluble form of HJV that suppresses BMP signaling and hepcidin expression by acting as a decoy that competes with membrane HJV for BMP ligands. Recent studies indicate that matriptase-2 binds and degrades HJV, leading to a decrease in cell surface HJV. In the present work, we show that matriptase-2 cleaves HJV at Arg(288), which produces one major soluble form of HJV. This shed form of HJV has decreased ability to bind BMP6 and does not suppress BMP6-induced hepcidin expression. These results suggest that the matriptase-2 and proprotein convertase-cleavage products have different roles in the regulation of hepcidin expression.     

胰高血糖素样肽1受体--治疗糖尿病新药的研究热点

胰高血糖素样肽l(glucagon—like peptide—l,GLP-1)与胰岛素分泌和糖代谢调节密切相关。GLP-1与其受体(GLP-1receptor,GLP-1R)结合后,主要通过cAMP和P13K两条信号途径,促进胰岛素的分泌,刺激胰岛β细胞的增殖和分化。对GLP-1R结构和信号传导机制的研究,有助于了解其在糖尿病病理进程中的作用,为开发新型糖尿病治疗药物指明方向。