Platelet bioenergetic profiling uncovers a metabolic pattern of high dependency on mitochondrial fatty acid oxidation in type 2 diabetic patients who developed in-stent restenosis.

Although platelet bioenergetic dysfunction is evident early in the pathogenesis of diabetic macrovascular complications, the bioenergetic characteristics in type 2 diabetic patients who developed coronary in-stent restenosis (ISR) and their effects on platelet function remain unclear. Here, we performed platelet bioenergetic profiling to characterize the bioenergetic alterations in 28 type 2 diabetic patients with ISR compared with 28 type 2 diabetic patients without ISR (non-ISR) and 28 healthy individuals. Generally, platelets from type 2 diabetic patients with ISR exhibited a specific bioenergetic alteration characterized by high dependency on fatty acid (FA) oxidation, which subsequently induced complex III deficiency, causing decreased mitochondrial respiration, increased mitochondrial oxidant production, and low efficiency of mitochondrial ATP generation. This pattern of bioenergetic dysfunction showed close relationships with both α-granule and dense granule secretion as measured by surface P-selectin expression, ATP release, and profiles of granule cargo proteins in platelet releasates. Importantly, ex vivo reproduction of high dependency on FA oxidation by exposing non-ISR platelets to its agonist mimicked the bioenergetic dysfunction observed in ISR platelets and enhanced platelet secretion, whereas pharmaceutical inhibition of FA oxidation normalized the respiratory and redox states of ISR platelets and diminished platelet secretion. Further, causal mediation analyses identified a strong association between high dependency on FA oxidation and increased angiographical severity of ISR, which was significantly mediated by the status of platelet secretion. Our findings, for the first time, uncover a pattern of bioenergetic dysfunction in ISR and enhance current understanding of the mechanistic link of high dependency on FA oxidation to platelet abnormalities in the context of diabetes.

Inhibition of mitochondrial complex I leading to NAD+/NADH imbalance in type 2 diabetic patients who developed late stent thrombosis: Evidence from an integrative analysis of platelet bioenergetics and metabolomics.

Type 2 diabetes mellitus (T2DM) is a strong indicator of late stent thrombosis (LST). Platelet bioenergetic dysfunction, although critical to the pathogenesis of diabetic macrovascular complications, remains uncharacterized in T2DM patients who developed LST. Here, we explored the mechanistic link between the alterations in platelet bioenergetics and LST in the setting of T2DM. Platelet bioenergetics, metabolomics, and their interactomes were analyzed in a nested case-control study including 15 T2DM patients who developed LST and 15 matched T2DM patients who did not develop LST (non-LST). Overall, we identified a bioenergetic alteration in T2DM patients with LST characterized by an imbalanced NAD+/NADH redox state resulting from deficient mitochondrial complex I (NADH: ubiquinone oxidoreductase) activity, which led to reduced ATP-linked and maximal mitochondrial respiration, increased glycolytic flux, and platelet hyperactivation compared with non-LST patients. Congruently, platelets from LST patients exhibited downregulation of tricarboxylic acid cycle and NAD+ biosynthetic pathways as well as upregulation of the proximal glycolytic pathway, a metabolomic change that was primarily attributed to compromised mitochondrial respiration rather than increased glycolytic flux as evidenced by the integrative analysis of bioenergetics and metabolomics. Importantly, both bioenergetic and metabolomic aberrancies in LST platelets could be recapitulated ex vivo by exposing the non-LST platelets to a low dose of rotenone, a complex I inhibitor. In contrast, normalization of the NAD+/NADH redox state, either by increasing NAD+ biosynthesis or by inhibiting NAD+ consumption, was able to improve mitochondrial respiration, inhibit mitochondrial oxidant generation, and consequently attenuate platelet aggregation in both LST platelets and non-LST platelets pretreated with low-dose rotenone. These data, for the first time, delineate the specific patterns of bioenergetic and metabolomic alterations for T2DM patients who suffer from LST, and establish the deficiency of complex I-derived NAD+ as a potential pathogenic mechanism in platelet abnormalities.

A novel 6-metabolite signature for prediction of clinical outcomes in type 2 diabetic patients undergoing percutaneous coronary intervention.

BACKGROUND: Outcome prediction tools for patients with type 2 diabetes mellitus (T2DM) undergoing percutaneous coronary intervention (PCI) are lacking. Here, we developed a machine learning-based metabolite classifier for predicting 1-year major adverse cardiovascular events (MACEs) after PCI among patients with T2DM. METHODS: Serum metabolomic profiling was performed in a nested case-control study of 108 matched pairs of patients with T2DM occurring and not occurring MACEs at 1 year after PCI, then the matched pairs were 1:1 assigned into the discovery and internal validation sets. External validation was conducted using targeted metabolite analyses in an independent prospective cohort of 301 patients with T2DM receiving PCI. The function of candidate metabolites was explored in high glucose-cultured human aortic smooth muscle cells (HASMCs). RESULTS: Overall, serum metabolome profiles differed between diabetic patients with and without 1-year MACEs after PCI. Through VSURF, a machine learning approach for feature selection, we identified the 6 most important metabolic predictors, which mainly targeted the nicotinamide adenine dinucleotide (NAD+) metabolism. The 6-metabolite model based on random forest and XGBoost algorithms yielded an area under the curve (AUC) of ≥ 0.90 for predicting MACEs in both discovery and internal validation sets. External validation of the 6-metabolite classifier also showed good accuracy in predicting MACEs (AUC 0.94, 95% CI 0.91-0.97) and target lesion failure (AUC 0.89, 95% CI 0.83-0.95). In vitro, there were significant impacts of altering NAD+ biosynthesis on bioenergetic profiles, inflammation and proliferation of HASMCs. CONCLUSION: The 6-metabolite model may help for noninvasive prediction of 1-year MACEs following PCI among patients with T2DM.

Poly(ADP-Ribose) Polymerase Activity and Coronary Artery Disease in Type 2 Diabetes Mellitus: An Observational and Bidirectional Mendelian Randomization Study.

OBJECTIVE: Experimental evidence suggests a close link between PARP (poly[ADP-ribose] polymerase) activation and diabetic endothelial dysfunction. Here, we tested whether PARP activity in circulating leukocytes was associated with coronary artery disease (CAD) among patients with type 2 diabetes mellitus (T2DM). Approach and Results: We performed observational and bidirectional Mendelian randomization studies of 3149 Chinese individuals with T2DM who underwent coronary angiography, with leukocyte PARP activity, 16 tag single-nucleotide polymorphisms in PARP1 and PARP2, and 17 CAD risk single-nucleotide polymorphisms analyzed. Of 3149 participants, 1180 who further received percutaneous coronary intervention were prospectively followed for 1 year to track major adverse cardiovascular and cerebrovascular events. Overall, greater PARP activity was cross-sectionally associated with an odds ratio of 1.23 for obstructive CAD, and prospectively with a hazard ratio of 1.34 for 1-year major adverse cardiovascular and cerebrovascular events after percutaneous coronary intervention (both P<0.001). Using a genetic score of 5 screened single-nucleotide polymorphisms in PARP1 and PARP2 as the instrumental variable, genetically predicted elevation in PARP activity showed a causal association with obstructive CAD (odds ratio=1.35, P<0.001). In contrast, the genetic risk of CAD had no significant effect on PARP activity. Ex vivo and in vitro cultures of human monocytes showed that rs747657, as the lead single-nucleotide polymorphism strongly associated with PARP activity, caused the differential binding of transcription factor GATA2 (GATA-binding protein 2) to an intronic regulatory region in PARP1, thus modulating PARP1 expression and PARP activity. CONCLUSIONS: Greater PARP activity may have causal roles in the development of obstructive CAD among patients with diabetes mellitus.

Joint effects of mitochondrial DNA4977 deletion and serum folate deficiency on coronary artery disease in type 2 diabetes mellitus.

BACKGROUND & AIMS: The 4977-bp mitochondrial deletion (mtDNA4977 deletion), as a hallmark of mitochondrial oxidative damage, may play an important role in coronary artery disease (CAD), but its interaction with folate deficiency among diabetic patients is largely unknown. We aimed to explore the joint association of leukocyte mtDNA4977 deletion and serum folate status with obstructive CAD in Chinese adults with type 2 diabetes. METHODS: We cross-sectionally analyzed the angiographic data of 2017 diabetic patients without B-vitamin supplementation. Of the 2017 participants, 756 who received percutaneous coronary intervention (PCI) completed prospective follow-up of one year. In vitro, we explored the mediation effects of mitochondrial reactive oxygen species (mtROS) in folic acid (FA)-deficient human aortic smooth muscle cells (HASMCs) under hyperglycemic conditions. RESULTS: Cross-sectionally, the multivariate odds ratios (ORs) for obstructive CAD were 1.41 (95% CI: 1.29-1.55) for greater mtDNA4977 deletion, and 1.15 (95% CI: 1.05-1.25) for lower folate levels. Particularly, the combination of high mtDNA4977 deletion (top tertile) and folate deficiency (serum folate < 6 ng/mL) was associated with more than 2-fold increased odds of having obstructive CAD and higher degrees of coronary stenosis. Prospectively, the hazard ratio for all-cause death at 1-year after PCI was up to 2.37 (95% CI: 1.21-4.63) for folate-deficient participants in the top tertile of mtDNA4977 deletion. In HASMCs, the adverse effects of FA deficiency were aggravated by induction of mtROS, and attenuated by scavenging of mtROS. CONCLUSIONS: The risk of obstructive CAD may be greatly increased by the interaction between greater mtDNA4977 deletion and folate deficiency among diabetic patients.

Mitochondrial 8-hydroxy-2'-deoxyguanosine and coronary artery disease in patients with type 2 diabetes mellitus.

BACKGROUND: Little is known about whether mitochondria 8-hydroxy-2'-deoxyguanosine (8-OHdG), a biomarker of mitochondrial DNA (mtDNA) oxidative damage, contributes to the development of coronary artery disease (CAD) in diabetic patients. Here, we explored the associations of mtDNA 8-OHdG in leukocytes with obstructive CAD, coronary stenosis severity, cardiovascular biomarkers, and 1-year adverse outcomes after coronary revascularization in patients with type 2 diabetes mellitus (T2DM). METHODS: In a total of 1920 consecutive patients with T2DM who underwent coronary angiography due to symptoms of angina or angina equivalents, the presence of obstructive CAD, the number of diseased vessels with ≥ 50% stenosis, and modified Gensini score were cross-sectionally evaluated; the level of mtDNA 8-OHdG was quantified by quantitative PCR. Then, 701 of 1920 diabetic patients who further received coronary revascularization completed 1-year prospective follow-up to document major adverse cardiovascular and cerebral events (MACCEs). In vitro experiments were also performed to observe the effects of mtDNA oxidative damage in high glucose-cultured human umbilical vein endothelial cells (HUVECs). RESULTS: Cross-sectionally, greater mtDNA 8-OHdG was associated with increased odds of obstructive CAD (odds ratio [OR] 1.38, 95% CI confidence interval 1.24-1.52), higher degree of coronary stenosis (number of diseased vessels: OR 1.29, 95% CI 1.19-1.41; modified Gensini scores: OR 1.28, 95% CI 1.18-1.39), and higher levels of C-reactive protein (ß 0.18, 95% CI 0.06-0.31) after adjusting for confounders. Sensitivity analyses using propensity score matching yielded similar results. Stratification by smoking status showed that the association between mtDNA 8-OHdG and obstructive CAD was most evident in current smokers (Pinteration < 0.01). Prospectively, the adjusted hazards ratio per 1-SD increase in mtDNA 8-OHdG was 1.59 (95% CI 1.33-1.90) for predicting 1-year MACCEs after revascularization. In HUVECs, exposure to antimycin A, an inducer for mtDNA oxidative damage, led to adverse alterations in markers of mitochondrial and endothelia function. CONCLUSION: Greater mtDNA 8-OHdG in leukocytes may serve as an independent risk factor for CAD in patients with T2DM.

Identification of a blood-based 12-gene signature that predicts the severity of coronary artery stenosis: An integrative approach based on gene network construction, Support Vector Machine algorithm, and multi-cohort validation.

BACKGROUND AND AIMS: We aimed to identify a blood-based gene expression score (GES) to predict the severity of coronary artery stenosis in patients with known or suspected coronary artery disease (CAD) by integrative use of gene network construction, Support Vector Machine (SVM) algorithm, and multi-cohort validation. METHODS: In the discovery phase, a public blood-based microarray dataset of 110 patients with known CAD was analyzed by weighted gene coexpression network analysis and protein-protein interaction network analysis to identify candidate hub genes. In the training set with 151 CAD patients, bioinformatically identified hub genes were experimentally verified by real-time polymerase chain reaction, and statistically filtered with the SVM algorithm to develop a GES. Internal and external validation of GES was performed in patients with suspected CAD from two validation cohorts (n = 209 and 206). RESULTS: The discovery phase screened 15 network-centric hub genes significantly correlated with the Duke CAD Severity Index. In the training cohort, 12 of 15 hub genes were filtered to construct a blood-based GES12, which showed good discrimination for higher modified Gensini scores (AUC: 0.798 and 0.812), higher Sullivan Extent scores (AUC: 0.776 and 0.778), and the presence of obstructive CAD (AUC: 0.834 and 0.792) in two validation cohorts. A nomogram comprising GES12, smoking status, hypertension status, low density lipoprotein cholesterol level, and body mass index further improved performance, with respect to discrimination, risk classification, and clinical utility, for prediction of coronary stenosis severity. CONCLUSIONS: GES12 is useful in predicting the severity of coronary artery stenosis in patients with known or suspected CAD.

Leukocyte Mitochondrial DNA Copy Number and Risk of Thyroid Cancer: A Two-Stage Case-Control Study.

Background: Mitochondrial DNA copy number (mtDNA-CN) may contribute to the development of various cancer types in a tumor-specific manner. However, little is known about whether leukocyte mtDNA content confers susceptibility to thyroid cancer (TC). This study aimed to investigate the associations of leukocyte mtDNA-CN with the risk and clinicopathological features of TC in a Chinese population. Methods: In this two-stage case-control study with a total of 402 TC patients and 406 controls, leukocyte mtDNA-CN content was measured with a quantitative PCR method. In a subset of 100 cases and 100 controls, levels of leukocyte 8-hydroxy-2'-deoxyguanosine (8-OHdG) and plasma malondialdehyde, as two biomarkers for oxidative stress, were determined by ELISA and colorimetric kits, respectively. Results: In a combined analysis of discovery and validation sets, high mtDNA-CN content was positively associated with increased TC risk, after adjusting for confounders (OR for per SD increment: 1.43; 95%CI, 1.23-1.66; P < 0.001; OR for tertile 3 vs. tertile 1: 2.10; 95%CI, 1.48-3.00; P trend < 0.001). This linear dose-response relationship was more pronounced in subtype analyses for papillary and follicular thyroid carcinoma (P < 0.001 for all), as well as in subgroup analyses for subjects with overweight and obesity (P interaction = 0.015). In TC patient, we observed the positive correlations of mtDNA-CN with advanced TNM stage (P = 0.006) and the presence of lymph node metastasis (P = 0.012). Leukocyte mtDNA-CN content was also identified to increase with the levels of leukocyte 8-OHdG (P < 0.001), a biomarker for oxidative DNA damage. Conclusion: Our data suggest that the increase in leukocyte mtDNA-CN content may correlate with oxidative DNA damage, and serve as an independent risk factor for TC.

Leukocyte telomere length, mitochondrial DNA copy number, and coronary artery disease risk and severity: A two-stage case-control study of 3064 Chinese subjects.

BACKGROUND AND AIMS: Leukocyte telomere length (TL) and mitochondrial DNA copy number (mtDNA-CN), as hallmarks of cellular aging, may be involved in the development of coronary artery disease (CAD) by modulating oxidative stress. This study aimed to investigate the effects of leukocyte TL and mtDNA-CN alone or in combination on CAD risk and severity in the Chinese population. METHODS: In this two-stage case-control study with 1511 CAD patients and 1553 controls, leukocyte TL and mtDNA-CN were determined by a quantitative PCR assay. Three oxidative parameters, including leukocyte 8-hydroxy-2'-deoxyguanosine (8-OHdG), plasma malondialdehyde, and plasma reactive oxygen species (ROS), were quantified by ELISA or colorimetric kits in a subset of 129 cases and 129 controls. RESULTS: In the combined cohort, each 1-SD decrease in TL and mtDNA-CN was significantly associated with a 1.17-fold and 1.14-fold increased risk of CAD (p < 0.001 for all), respectively, after adjusting for confounders. The aggregated score, which reflected the cumulative dosage of the tertiles of TL and mtDNA-CN, showed inverse dose-response correlations with CAD risk (ptrend < 0.001), and severity, as determined by the severity of clinical presentations (ptrend = 0.037), the presence of multi-vessel CAD (ptrend = 0.004), and modified Gensini scores (ptrend = 0.009). Similar dose-response relations of the aggregated score to leukocyte 8-OHdG and plasma ROS were also identified. CONCLUSIONS: Our data suggested reductions in both TL and mtDNA-CN as independent risk factors for CAD. The combination of TL and mtDNA-CN might jointly contribute to CAD risk, CAD severity, and oxidative stress.

Identification of DAPK1 Promoter Hypermethylation as a Biomarker for Intra-Epithelial Lesion and Cervical Cancer: A Meta-Analysis of Published Studies, TCGA, and GEO Datasets.

Background: Promoter hypermethylation in death-associated protein kinase 1 (DAPK1) gene has been long linked to cervical neoplasia, but the established results remained controversial. Here, we performed a meta-analysis to assess the associations of DAPK1 promoter hypermethylation with low-grade intra-epithelial lesion (HSIL), high-grade intra-epithelial lesion (HSIL), cervical cancer (CC), and clinicopathological features of CC. Methods: Published studies with qualitative methylation data were initially searched from PubMed, Web of Science, EMBASE, and China National Knowledge Infrastructure databases (up to March 2018). Then, quantitative methylation datasets, retrieved from the Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases, were pooled to validate the results of published studies. Results: In a meta-analysis of 37 published studies, DAPK1 promoter hypermethylation progressively increased the risk of LSIL by 2.41-fold (P = 0.012), HSIL by 7.62-fold (P < 0.001), and CC by 23.17-fold (P < 0.001). Summary receiver operating characteristic curves suggested a potential diagnostic value of DAPK1 promoter hypermethylation in CC, with a large area-under-the-curve of 0.83, a high specificity of 97%, and a moderate sensitivity of 59%. There were significant impacts of DAPK1 promoter hypermethylation on histological type (odds ratio (OR) = 3.53, P < 0.001) and FIGO stage of CC (OR = 2.15, P = 0.003). Then, a pooled analysis of nine TCGA and GEO datasets, covering 13 CPG sites within DAPK1 promoter, identified eight CC-associated sites, six sites with diagnostic values for CC (pooled specificities: 74-90%; pooled sensitivities: 70-81%), nine loci associated with the histological type of CC, and all 13 loci with down-regulated effects on DAPK1 mRNA expression. Conclusion: The meta-analysis suggests that DAPK1 promoter hypermethylation is significantly associated with the disease severity of cervical neoplasia. DAPK1 methylation detection exhibits a promising ability to discriminate CC from cancer-free controls.

PARP-1 Variant Rs1136410 Confers Protection against Coronary Artery Disease in a Chinese Han Population: A Two-Stage Case-Control Study Involving 5643 Subjects.

Inhibition of poly(ADP-ribose) polymerase (PARP) may protect against coronary artery disease (CAD) in animal models, and rs1136410, a non-synonymous single nucleotide polymorphism (SNP) in PARP-1, has a potential impact on PARP activities in vitro. This two-stage case-control study, involving 2803 CAD patients and 2840 controls, aimed to investigate the associations of PARP-1 rs1136410 with CAD development, lipid levels, PARP activities, 8-hydroxy-2'-dexyguanosine (8-OHdG), and interleukin (IL)-6 levels in a Chinese Han population. Assuming a recessive model, the variant genotype GG of SNP rs1136410 showed a significantly inverse association with CAD risk (adjusted odds ratio (OR) = 0.73, P < 0.001), left main coronary artery (LMCA) lesions (P = 0.003), vessel scores (P = 0.003), and modified Gensini scores (P < 0.001). There were significant correlations of SNP rs1136410 with higher levels of total cholesterol (TC) and lower levels of high-density lipoprotein cholesterol (HDL-c). In gene-environment interaction analyses, participants with the variant genotype GG, but without smoking habit, type 2 diabetes mellitus, and hyperlipidemia, conferred an 84% (P < 0.001) decreased risk of CAD. The genotype-phenotype correlation analyses further supported the functional roles of SNP rs1136410 in decreasing PARP activities and 8-OHdG levels. Taken together, our data suggest that SNP rs1136410 may confer protection against CAD through modulation of PARP activities and gene-environment interactions in a Chinese Han population.

Associations of P16INK4a promoter hypermethylation with squamous intra-epithelial lesion, cervical cancer and their clinicopathological features: a meta-analysis.

To assess the associations of P16INK4a methylation status with low-grade squamous intra-epithelial lesion (LSIL), high-grade squamous intra-epithelial lesion (HSIL), cervical cancer (CC) and their clinicopathological features, a meta-analysis with 29 eligible studies was conducted. Pooled odds ratios (ORs) with their 95% confidence intervals (CIs) were estimated to assess the strength of the associations. Heterogeneity, sensitivity of pooled results and publication bias were also evaluated. Overall, there was an increasing trend of P16INK4a hypermethylation rates among LSIL (21.4%), HSIL (30.9%) and CC (35.0%) specimens. P16INK4a hypermethylation was significantly associated with the increased risk of LSIL, HSIL and CC, with the pooled ORs of 3.26 (95% CI: 1.86-5.71), 5.80 (95% CI: 3.80-8.84) and 12.17 (95% CI: 5.86-25.27), respectively. A significant association was also found between P16INK4a hypermethylation and smoking habit (OR = 3.88, 95% CI: 2.13-7.08). Taken together, meta-analysis results support P16INK4a hypermethylation as an epigenetic marker for the progression of cervical carcinogenesis.

Associations of PARP-1 variant rs1136410 with PARP activities, oxidative DNA damage, and the risk of age-related cataract in a Chinese Han population: A two-stage case-control analysis.

OBJECTIVE: To investigate whether a single nucleotide polymorphism (SNP) rs1136410 in the poly (ADP-ribose) polymerase-1 (PARP-1) gene was associated with PARP activities, 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels, and the risk of age-related cataract (ARC) in a Chinese Han population. METHODS: In this two-stage case-control study with a total of 1010 ARC patients and 1045 controls, SNP rs1136410 was genotyped by high-resolution melting analyses (HRM). PARP activities and 8-OHdG levels in peripheral blood mononuclear cells (PBMCs) were determined by ELISA kits. RESULTS: In discovery, replication, and their merged sets, the variant genotypes (AG+GG) of SNP rs1136410 were significantly associated with an increased risk of ARC under a dominant model (Adjusted odds ratio (OR)=1.42, Padj=0.001 for the merged set). This association was further identified in subtype analyses for cortical ARC (Adjusted OR=1.69, Padj<0.001). In subgroup analyses, we identified a significant interaction between SNP rs1136410 and smoking habit in increasing ARC risk (Pinter=0.019). Moreover, ARC patients had lower activities of PARP and higher levels of 8-OHdG than controls. There were significant correlations of SNP rs1136410 with decreased PARP activities and increased 8-OHdG levels in controls and patients with cortical ARC. CONCLUSIONS: This study suggests that SNP rs1136410 may confer susceptibility to ARC by affecting PARP activities and oxidative DNA damage.

HDAC9 Variant Rs2107595 Modifies Susceptibility to Coronary Artery Disease and the Severity of Coronary Atherosclerosis in a Chinese Han Population.

A previous genome-wide association study showed that a single nucleotide polymorphism (SNP) rs2107595 in histone deacetylase 9 (HDAC9) gene was associated with large artery stroke (LAS) in Caucasians. Based on the similar atherosclerotic pathogenesis between LAS and coronary artery disease (CAD), we aimed to evaluate the associations of SNP rs2107595 with CAD risk and the severity of coronary atherosclerosis in a Chinese Han population, and explore the potential gene-environment interactions among SNP rs2107595 and conventional CAD risk factors. In a two-stage case-control study with a total of 2317 CAD patients and 2404 controls, the AG + AA genotypes of SNP rs2107595 were significantly associated with increased CAD risk (Adjusted odds ratio (OR) = 1.23, Padj = 0.001) and higher modified Gensini scores (Adjusted OR = 1.38, Padj < 0.001). These associations remained significant in subtype analyses for unstable angina pectoris (UAP), non-ST-segment elevation myocardial infarction (NSTEMI) and ST-segment elevation myocardial infarction (STEMI). Subgroup and multifactor dimensionality reduction analyses (MDR) further found the gene-environment interactions among SNP rs2107595, body mass index, type 2 diabetes and hyperlipidemia in CAD risk and the severity of coronary atherosclerosis. Moreover, patients with CAD had higher levels of HDAC9 mRNA expression and plasma HDAC9 than controls. Subsequent genotype-phenotype analyses observed the significant correlations of SNP rs2107595 with HDAC9 mRNA expression and plasma HDAC9 levels in controls and patients with NSTEMI and STEMI. Taken together, our data suggest that SNP rs2107595 may contribute to coronary atherosclerosis and CAD risk through a possible mechanism of regulating HDAC9 expression and gene-environment interactions.

Associations of polymorphisms in TXNIP and gene-environment interactions with the risk of coronary artery disease in a Chinese Han population.

Single nucleotide polymorphisms (SNPs) in thioredoxin-interacting protein (TXNIP) gene may modulate TXNIP expression, then increase the risk of coronary artery disease (CAD). In a two-stage case-control study with a total of 1818 CAD patients and 1963 controls, we genotyped three SNPs in TXNIP and found that the variant genotypes of SNPs rs7212 [odds ratio (OR) = 1.26, P = 0.001] and rs7211 (OR = 1.23, P = 0.005) were significantly associated with increased CAD risk under a dominant model. In haplotype analyses, compared with the reference haplotype, haplotype 'G-T' had a 1.22-fold increased risk of CAD (P = 0.003). We also observed the cumulative effects of SNPs rs7212 and rs7211 on CAD risk and the severity of coronary atherosclerosis. Moreover, the gene-environment interactions among the variant genotypes of SNP rs7212, smoking habit, alcohol drinking habit and history of type 2 diabetes were associated with a 3.70-fold increased risk of CAD (P < 0.001). Subsequent genotype-phenotype correlation analyses further observed the significant effects of SNP rs7212 on TXNIP mRNA expression, plasma TXNIP and malondialdehyde levels. Taken together, our data suggest that TXNIP SNPs may individually and cumulatively affect CAD risk through a possible mechanism for regulating TXNIP expression and gene-environment interactions.

Associations of Polymorphisms in MTHFR Gene with the Risk of Age-Related Cataract in Chinese Han Population: A Genotype-Phenotype Analysis.

Homocysteine (Hcy) is a potential risk factor for age-related cataract (ARC). Methylenetetrahydrofolate reductase (MTHFR) is the key enzyme for Hcy metabolism, and variants of MTHFR may affect MTHFR enzyme activity. This study mainly evaluated the associations between variants in MTHFR gene, plasma MTHFR enzyme activity, total Hcy (tHcy) levels and ARC risk in Chinese population. Four single nucleotide polymorphisms (SNPs) in MTHFR gene were genotyped using the high-resolution melting (HRM) method in 502 ARC patients (mean age, 70.2 [SD, 9.0], 46.0% male) and 890 healthy controls (mean age, 67.1 [SD, 11.1], 47.6% male). The plasma MTHFR activity, folic acid (FA), vitamins B12 and B6 levels were detected by enzyme-linked immunosorbent assays (ELISA). The plasma tHcy levels were measured by an automated enzymatic assay. After the Bonferroni correction, the minor allele T of SNP rs1801133 showed a significant association with an increased risk of overall ARC (OR = 1.26, P = 0.003). Consistent association was also found between SNP rs1801133 and cortical ARC risk (OR = 1.44, P = 0.003). Haplotype analyses revealed an adverse effect of the haplotype "C-A-T-C" (alleles in order of SNPs rs3737967, rs1801131, rs1801133 and rs9651118) on ARC risk (OR = 1.55, P = 0.003). Moreover, in a joint analysis of SNPs rs9651118 and rs1801133, subjects with two unfavorable genotypes had a 1.76-fold increased risk of ARC compared with the reference group, and a statistically significant dose-response trend (Ptrend = 0.001) was also observed. Further, in healthy controls and patients with cortical ARC, the allele T of SNP rs1801133 and the increasing number of unfavorable genotypes were significantly correlated with decreased MTHFR activity as well as increased tHcy levels. However, there was no significant association between FA, vitamins B12, B6 levels and MTHFR variants. Our data indicated that variants in MTHFR gene might individually and jointly influence susceptibility to ARC by affecting MTHFR enzyme activity and tHcy levels.

Associations of lipid levels susceptibility loci with coronary artery disease in Chinese population.

BACKGROUND: Recent genome-wide association studies (GWAS) have identified several single nucleotide polymorphisms (SNPs) that were associated with blood lipid levels in Caucasians. This study investigated whether these loci influenced lipid levels and whether they were associated with the risk of coronary artery disease (CAD) and its angiographic severity in Chinese population. METHODS: Six SNPs were genotyped in 1100 CAD cases and 1069 controls using the high-resolution melting (HRM) method. Coronary atherosclerosis severity was assessed by the vessel scores and the Gensini scoring system. RESULTS: Among the 6 SNPs and the genetic risks scores (GRS), the minor alleles of HNF1A rs1169288 (odd ratio (OR) = 1.18, 95% confidence interval (CI) 1.05-1.33, P = 0.006) and MADD-FOLH1 rs7395662 (OR = 1.20, 95% CI 1.07-1.36, P = 0.002) as well as the GRS (P = 1.06 × 10(-5)) were significantly associated with increased risk of CAD after false discovery rate (FDR) correction. The vessel (P = 0.013) and Gensini scores (ß = 0.113, P = 0.002) differed among CAD patients with different SNP rs1169288 C > T genotypes. The multiple linear regression analyses using an additive model revealed that the minor allele C of SNP rs1169288 (ß = 0.060, P = 0.001) and the GRS (ß = 0.033, P = 3.59 × 10(-4)) were significantly associated with increased total cholesterol (TC) levels, the minor allele A of SNP rs7395662 (ß = -0.024, P = 0.007) and the GRS (ß = -0.013, P = 0.004) were significantly associated with decreased high-density lipoprotein cholesterol (HDL-c) levels. CONCLUSIONS: The present study demonstrated that SNPs rs1169288, rs7395662 and the GRS were significantly associated with lipid levels and the risk of CAD in Chinese population. Furthermore, the allele C of SNP rs1169288 increased the odds of coronary atherosclerosis severity.

Angiotensin-converting enzyme gene polymorphisms and risk for sporadic Alzheimer's disease: a meta-analysis.

Numerous studies have tested for associations between common polymorphisms of the angiotensin-converting enzyme gene and sporadic Alzheimer disease (SAD), but results have been inconclusive. Using meta-analysis, our study aimed to clarify the nature of the genetic risks contributed by the three polymorphisms (rs4291, rs4343, rs1800764) for developing SAD. Through searching of Pubmed, Embase, Alzgene and manually searching relevant references, a total of 14 articles with 26 independent studies were included. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of the association studies. The heterogeneity across the studies was tested, as was publication bias. We observed significant association between SNP rs4291 and SAD using allelic comparison (OR = 1.08, 95% CI 1.03-1.14), homozygote comparison (OR = 1.16, 95% CI 1.04-1.30) and the recessive model (OR = 1.10, 95% CI 1.02-1.18). Association with SNP rs1800764 was revealed but it was not sufficiently robust to withstand the Benjamini-Hochberg method and stepdown Bonferroni correction. Significant association was not identified in the analysis for SNP rs4343. In subgroup analyses, the risk of SAD associated with SNP rs4291 appeared to be significant among Caucasians and in older cases (mean age ≥75 years). Our results confirmed a significant but modest association between SNP rs4291 and SAD susceptibility. Further study of the pathogenetic characteristics of this polymorphism and independent confirmation of the association in larger studies are warranted.

Angiotensin-converting enzyme insertion/deletion polymorphism is not a major determining factor in the development of sporadic Alzheimer disease: evidence from an updated meta-analysis.

Angiotensin-converting enzyme gene (ACE) insertion/deletion (I/D) polymorphism have long been linked to sporadic Alzheimer disease (SAD), but the established data remained controversial. To clarify this inconsistency, a comprehensive meta-analysis was conducted. Through searching of Pubmed, Embase, Alzgene, China National Knowledge Infrastructure (CNKI) and manually searching relevant references, 53 independent studies from 48 articles were included, involving a total of 8153 cases and 14932 controls. The strength of association was assessed by using odds ratios (ORs) with 95% confidence intervals (CIs). Further stratified analyses and heterogeneity analyses were tested, as was publication bias. Overall, significant associations were revealed between I/D polymorphism and SAD risk using allelic comparison (OR = 1.09, 95%CI = 1.01-1.17, p = 0.030), homozygote comparison (OR = 1.17, 95%CI = 1.01-1.34, p = 0.030) and the dominant model (OR = 1.16, 95%CI = 1.04-1.29, p = 0.008), but they were not sufficiently robust to withstand the false-positive report probability (FPRP) analyses. Otherwise, in subgroup analyses restricted to the high quality studies, the large sample size studies and studies with population-based controls, no significant association was observed in any genetic models. In summary, the current meta-analysis suggested that the ACE I/D polymorphism is unlikely to be a major determining factor in the development of SAD.

Associations between AT-rich interactive domain 5B gene polymorphisms and risk of childhood acute lymphoblastic leukemia: a meta-analysis.

Previous genome-wide association studies (GWAS) have implicated several single nucleotide polymorphisms (SNPs) in the AT-rich interactive domain 5B (ARID5B) gene with childhood acute lymphoblastic leukemia (ALL). However, replicated studies reported some inconsistent results in different populations. Using meta-analysis, we here aimed to clarify the nature of the genetic risks contributed by the two polymorphisms (rs10994982, rs7089424) for developing childhood ALL. Through searches of PubMed, EMBASE, and manually searching relevant references, a total of 14 articles with 16 independent studies were included. Odds ratios (ORs) with 95% confidence intervals (95%CI) were calculated to assess the associations. Both SNPs rs10994982 and rs7089424 showed significant associations with childhood ALL risk in all genetic models after Bonferroni correction. Furthermore, subtype analyses of B-lineage ALL provided strong evidence that SNP rs10994982 is highly associated with the risk of developing B-hyperdiploid ALL. These results indicate that SNPs rs10994982 and rs7089424 are indeed significantly associated with increased risk of childhood ALL.