Role of microRNAs 221/222 on Statin Induced Nitric Oxide Release in Human Endothelial Cells

Background

Nitric oxide (NO) has been largely associated with cardiovascular protection through improvement of endothelial function. Recently, new evidence about modulation of NO release by microRNAs (miRs) has been reported, which could be involved with statin-dependent pleiotropic effects, including anti-inflammatory properties related to vascular endothelium function.

Objective

To evaluate the effects of cholesterol-lowering drugs including the inhibitors of cholesterol synthesis, atorvastatin and simvastatin, and the inhibitor of cholesterol absorption ezetimibe on NO release, NOS3 mRNA expression and miRs potentially involved in NO bioavailability.

Methods

Human umbilical vein endothelial cells (HUVEC) were exposed to atorvastatin, simvastatin or ezetimibe (0 to 5.0 μM). Cells were submitted to total RNA extraction and relative quantification of NOS3 mRNA and miRs -221, -222 and -1303 by qPCR. NO release was measured in supernatants by ozone-chemiluminescence.

Results

Both statins increased NO levels and NOS3 mRNA expression but no influence was observed for ezetimibe treatment. Atorvastatin, simvastatin and ezetimibe down-regulated the expression of miR-221, whereas miR-222 was reduced only after the atorvastatin treatment. The magnitude of the reduction of miR-221 and miR-222 after treatment with statins correlated with the increment in NOS3 mRNA levels. No influence was observed on the miR-1303 expression after treatments.

Conclusion

NO release in endothelial cells is increased by statins but not by the inhibitor of cholesterol absorption, ezetimibe. Our results provide new evidence about the participation of regulatory miRs 221/222 on NO release induction mediated by statins. Although ezetimibe did not modulate NO levels, the down-regulation of miR-221 could involve potential effects on endothelial function.     

苏州市汉族女性MTHFR与MTRR基因多态性

目的探讨苏州市汉族女性5,10-亚甲基四氢叶酸还原酶(MTHFR)和甲硫氨酸合成酶还原酶(MTRR)基因多态性的频率特征。方法以苏州市644例汉族女性为研究对象,检测MTHFR C677T、A1298C和MTRR A66G的基因分型。统计分析基因多态性的频率特征,并与已报道的其他地区汉族女性的数据进行比较。结果苏州市汉族女性的MTHFR C677T基因型和等位基因频率与淄博、郑州、松滋、昆明、德阳、惠州、琼海差异有统计学意义(P<0.05),MTHFR A1298C基因型和等位基因频率与淄博、松滋、德阳、惠州、琼海差异有统计学意义(P<0.05),MTRR A66G基因型和等位基因频率与琼海差异有统计学意义(P<0.05)。结论苏州市汉族女性MTHFR和MTRR基因多态性频率不同于其他地区,具有地域特异性。     

母亲MTHFD1及MTHFD2基因多态性与子代先天性心脏病的关联北大核心CSCD

目的探讨母亲亚甲基四氢叶酸脱氢酶(methylenetetrahydrofolate dehydrogenase,MTHFD)1、2(MTHFD1、MTHFD2)基因多态性与子代先天性心脏病(congenital heart disease,CHD)的关联。方法采用以医院为基础的病例对照研究,选取2017年11月至2020年3月在湖南省儿童医院就诊的683例单纯CHD患儿的母亲作为病例组,选取同时间段内就诊于同一家医院并排除任何先天畸形的740例儿童的母亲作为对照组。通过问卷调查,收集研究对象的相关暴露信息。完成调查问卷后,采集母亲5 mL静脉血,用于MTHFD1、MTHFD2基因多态性的检测。采用多因素logistic回归模型分析MTHFD1、MTHFD2基因多态性与CHD的关联;采用Haploview 4.2软件的四配子检验法构建单倍型,评估单倍型与CHD的关联;并采用广义多因子降维法和logistic回归法分析基因-基因交互作用与CHD的关联。结果多因素logistic回归分析显示,母亲MTHFD1基因rs11849530位点(GA vs AA:OR=1.49;GG vs AA:OR=2.04)和rs1256142位点(GA vs GG:OR=2.34;AA vs GG:OR=3.25)显著增加子代CHD的发生风险(P<0.05),而母亲MTHFD1基因rs1950902位点(AA vs GG:OR=0.57)和MTHFD2基因rs1095966位点(CA vs CC:OR=0.68)显著降低子代CHD的发生风险(P<0.05)。母亲携带单倍型G-G-G(OR=1.86)、G-A-G(OR=1.35)显著增加子代CHD的发生风险(P<0.05)。交互作用分析显示,母亲MTHFD基因2个位点(MTHFD1 rs1950902、MTHFD1 rs2236222)的一阶交互作用及3个位点(MTHFD1 rs1950902、MTHFD1 rs1256142、MTHFD2 rs1095966)的二阶交互作用可能与CHD的发生风险存在关联(P<0.05)。结论母亲MTHFD1、MTHFD2基因多态性及其单倍型,以及2个位点(MTHFD1 rs1950902、MTHFD1 rs2236222)和3个位点(MTHFD1 rs1950902、MTHFD1 rs1256142、MTHFD2 rs1095966)的交互作用与子代CHD的发生相关。     

Regulation of Nlrp3 inflammasome by dietary metabolites

The bidirectional communication between innate immune cells and energy metabolism is now widely appreciated to regulate homeostasis as well as chronic diseases that emerge from dysregulated inflammation. Macronutrients-derived from diet or endogenous pathways that generate and divert metabolites into energetic or biosynthetic pathways – regulate the initiation, duration and cessation of the inflammatory response. The NLRP3 inflammasome is an important innate sensor of structurally diverse metabolic damage-associated molecular patterns (DAMPs) that has been implicated in a wide range of inflammatory disorders associated with caloric excess, adiposity and aging. Understanding the regulators of immune-metabolic interactions and their contribution towards chronic disease mechanisms, therefore, has the potential to reduce disease pathology, improve quality of life in elderly and promote the extension of healthspan. Just as specialized subsets of immune cells dampen inflammation through the production of negative regulatory cytokines; specific immunoregulatory metabolites can deactivate inflammasome-mediated immune activation. Here, we highlight the role of energy substrates, alternative fuels and metabolic DAMPs in the regulation of the NLRP3 inflammasome and discuss potential dietary interventions that may impact sterile inflammatory disease.     

血浆同型半胱氨酸水平亚甲基四氢叶酸还原酶基因多态性与强直性脊柱炎的相关性研究

目的 探讨血浆同型半胱氨酸(Hcy)水平与强直性脊柱炎(AS)间的联系,分析AS患者MTHFR基因C677T突变的多态性,并探讨MTHFR基因多态性与AS的相关性.方法 运用酶联免疫吸附试验(ELISA)测定100例AS患者及60名健康志愿者血浆Hcy浓度,应用多聚酶链反应-限制性内切酶片段长度多态性(PCR-RELP)分析MTHFR基因的多态性.结果 AS患者血浆Hcy浓度明显高于对照组,两组间差异有统计学意义(P＜0.01);AS组T/T型、C/T型、C/C型基因频率分布及T、C等位基因频率与对照组比较差异无统计学意义(P＞0.05);AS组T/T基因型突变的比例与对照组比较差异有统计学意义(P＜0.05);AS组和对照组T/T型的血浆Hcy水平明显高于C/T型和C/C型(P＜0.01).Logistic回归分析显示高Hcy血症是AS发病的独立危险凶素(P＜0.01,OR=4.582,95%CI=1.984～10.585).结论 AS患者血浆Hcy浓度明显高于健康志愿者,高Hcy血症是AS发病的独立危险因素.MTHFR基因T/T型突变是血浆Hcy浓度升高的一个重要影响机制,MTHFR基因T/T型突变可能与AS的发生有相关性.     

MTHFR基因变异与2型糖尿病合并颈动脉粥样硬化症的关系

目的探讨亚甲基四氢叶酸还原酶（MTHFR）C677T基因多态性和2型糖尿病合并颈动粥样脉硬化症（DM＋CAS）的关系。方法采用聚合酶链反应-限制性片段长度多态性（PCR—RFLP）技术分别检测109例2型DM患者和90例DM＋CAS患者及100名健康对照者的MTHFR C677T基因多态性分布特征,同时检测血糖、血脂和血浆同型半胱氨酸（Hcy）、叶酸（FA）、维生素B12（VitB12）的水平。结果DM＋CAS组的TT基因频率（31.1％）、T等位基因频率（51．1％）明显高于DM组（18.4、33．1）和对照组（18％、33．5％）（均P〈0.05）;CC基因型频率（28．9％）和C等位基因频率（48．9％）均明显低于DM组（52.2％、66.9％）和对照组（53.0％、67．5％）（均P〈0．01）。DM＋CAS组的Hcy水平明显高于DM组和对照组（均P〈0．05）,而FA、VitB12明显低于DM组及对照组（均P〈0.05）;Hcy与FA、VitB1l2呈负相关。结论MTHFR C677T基因多态性与DM＋CAS有关,并影响Hcy水平。     

Impact of VKORC1 gene polymorphism on interindividual and interethnic warfarin dosage requirement— A systematic review and meta analysis

Introduction

Warfarin is the most widely used oral anticoagulant. It has been suggested that anticoagulation effect of warfarin is significantly associated with the polymorphism of certain genes, including Cytochrome P450 complex subunit 2C9 (CYP2C9), Vitamin K Epoxide Reductase Complex Subunit 1 (VKORC1), Gamma-Glutamyl Carboxylase (GGCX) and Apolipoprotein E (APOE) etc. The purpose of the present study was to conduct a systemic review and meta-analysis to investigate the relationship between mean daily warfarin dose (MDWD) and VKORC1 single nucleotide polymorphisms (SNPs).

Materials and Methods

Inclusion and exclusion criteria were made, and the studies between 2004 and present were searched. References were examined, and experts were consulted for additional information. Data were extracted. Revman 4.2.10 software was applied to analyze the relationship between MDWD and VKORC1 SNPs.

Results

Total 19 studies were included in the meta-analysis. The frequencies of 1173TT and − 1639 AA in Asian patients were higher than those in Caucasian and African populations. Patients with VKORC1 1173 CT and 1173 CC required 44% [95% Confidence Interval (CI); 32%, 56%] and 97% [73%, 122%] higher MDWD than 1173 TT carriers, − 1639GA and − 1639GG carriers required 52% [41%, 64%] and 102% [85%, 118%] higher MDWD than − 1639AA carriers, 3730GA and 3730AA carriers required 27% [3%, 58%] and 52% [3%, 109%] higher MDWD than 3730GG carriers. In addition, 1173C, − 1639 G and 3730 A carriers required 63% [44%, 82%], 61% [49%, 73%] and 32% [4%, 59%] higher MDWD than 1173TT, − 1639 AA and 3730GG, respectively. Sensitive analyses demonstrated that the impacts of gene polymorphism on warfarin dosage requirement were significantly different between Caucasian and Asian population, and the results of meta-analyses were stable and reliable.

Conclusion

This is the first meta-analysis about the impact of VKORC1 gene polymorphism on warfarin dose requirement. Our studies showed that gene polymorphisms of VKORC1 significantly associated with the variation of interindividual warfarin dose requirement variation, and the effects are different in ethnicities.     

Methylenetetrahydrofolate reductase (MTHFR) and breast cancer risk: a nested-case-control study and a pooled meta-analysis

Background A reduced activity of methylenetetrahydrofolate reductase (MTHFR) due to frequent C677T polymorphism affects DNA synthesis, repair and methylation and may be implicated in breast cancer risk. Methods We conducted a nested case-control study within a phase III prevention trial of tamoxifen. After a median follow-up of 81.2 months, 79 of the 5,408 hysterectomised women aged 35–70 years, who had received either tamoxifen 20 mg/day or placebo for 5 years, developed breast cancer. A total of 46 breast cancer cases and 80 unaffected controls matched to treatment allocation, years from randomization (±2 years) and age at randomization (±5 years), underwent genotyping for MTHFR C677T polymorphism using real time PCR. Results The MTHFR 677 genotype frequencies for CC, CT, TT in breast cancer cases were 30%, 44% and 26%, respectively, and 35%, 51%, 14% in controls. We observed a borderline significant odds ratio of 2.51 (95% CI, 0.96–6.55) of breast cancer in subjects with 677TT genotype, with no further association after stratifying for age and treatment group. A meta-analysis of 18 studies, including our own, showed an increased risk of breast cancer in premenopausal women with 677TT genotype, with an odds ratio of 1.42 (95% CI, 1.02–1.98). Conclusions Our study lends support to a positive association between the MTHFR variant homozygous allele 677TT and breast cancer risk. Additional studies are warranted to provide further insight into the role of folate metabolism deficiency and breast cancer.     

Homocysteine and methylenetetrahydrofolate reductase C677T and A1298C polymorphisms in Tunisian patients with severe coronary artery disease

Elevation in homocysteine and methylenetetrahydrofolate reductase (MTHFR) gene variants, C677T and A1298C, have been linked with atherothrombosis. However their exact contribution to coronary artery disease (CAD) remains controversial. Moreover, data from Tunisian patients are scarse. We examined the association of MTHFR C677T and A1298C, and changes in plasma homocysteine in 352 Tunisian patients with angiographically-demonstrated CAD, and 390 age and gender-matched healthy subjects. Significantly higher frequency of 677T allele and homozygous 677T/T genotype were seen in patients vs. control subjects; the distribution of A1298C alleles and genotypes being comparable in the two groups. Specific MTHFR haplotypes comprising 677C/1298A (P < 0.001) and 677T/1298A (P < 0.001) were negatively and positively associated with CAD, respectively. Plasma homocysteine concentration was significantly higher in 677T/T genotype with respect to 677C/C and 677C/T genotypes in patients and controls, but homocysteine levels were generally comparable between both groups. Univariate analysis identified 677T/1298A (P = 0.033) haplotype to be positively associated with CAD, which remained significant by multivariate analysis after adjusting for a number of covariates (P = 0.038). MTHFR C677T, but not A1298C SNPs, is associated with CAD and with elevated homocysteine levels in a Tunisian population. The negative and positive association of the 1298A allele with CAD being indicative of a neutral (absent) effect of the A1298C SNP on disease pathogenesis.