Aldehyde Dehydrogenase 2 (ALDH2) Deficiency, Obesity, and Atrial Fibrillation Susceptibility: Unraveling the Connection

Atrial fibrillation (AF), characterized by structural remodeling involving atrial myocardial degradation and fibrosis, is linked with obesity and transforming growth factor beta 1 (TGF-β1). Aldehyde dehydrogenase 2 (ALDH2) deficiency, highly prevalent in East Asian people, is paradoxically associated with a lower AF risk. This study investigated the impact of ALDH2 deficiency on diet-induced obesity and AF vulnerability in mice, exploring potential compensatory upregulation of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme-oxygenase 1 (HO-1). Wild-type (WT) and ALDH2*2 knock-in (KI) mice were administered a high-fat diet (HFD) for 16 weeks. Despite heightened levels of reactive oxygen species (ROS) post HFD, the ALDH2*2 KI mice did not exhibit a greater propensity for AF compared to the WT controls. The ALDH2*2 KI mice showed equivalent myofibril degradation in cardiomyocytes compared to WT after chronic HFD consumption, indicating suppressed ALDH2 production in the WT mice. Atrial fibrosis did not proportionally increase with TGF-β1 expression in ALDH2*2 KI mice, suggesting compensatory upregulation of the Nrf2 and HO-1 pathway, attenuating fibrosis. In summary, ALDH2 deficiency did not heighten AF susceptibility in obesity, highlighting Nrf2/HO-1 pathway activation as an adaptive mechanism. Despite limitations, these findings reveal a complex molecular interplay, providing insights into the paradoxical AF-ALDH2 relationship in the setting of obesity.

Causal links of α-thalassemia indices and cardiometabolic traits and diabetes: MR study

Our study aimed to investigate if genetic variants around 16p13.3's HBA1 locus, associated with erythrocyte indices and HbA1c levels, predict α-thalassemia-related erythrocyte indices, cardiometabolic traits, and diabetes risk in Taiwanese individuals. We analyzed Taiwan Biobank data, including whole-genome sequencing from 1,493 participants and genotyping arrays from 129,542 individuals. First, we performed regional association analysis using whole-genome sequencing data to identify genetic variants significantly associated with erythrocyte indices, confirming their linkage disequilibrium with the α0 thalassemia --SEA deletion mutation, a common cause of α-thalassemia in Southeast Asian populations. Deletion mutation sequencing further validated these variants' association with α-thalassemia. Subsequently, we analyzed genotyping array data, revealing associations between specific genetic variants and cardiometabolic traits, including lipid profiles, HbA1c levels, bilirubin levels, and diabetes risk. Using Mendelian randomization, we established causal relationships between α-thalassemia-related erythrocyte indices and cardiometabolic traits, elucidating their role in diabetes susceptibility. Our findings highlight genetic variants around the α-globin genes as surrogate markers for common α-thalassemia mutations in Taiwan, emphasizing the causal links between α-thalassemia-related erythrocyte indices, cardiometabolic traits, and heightened diabetes risk.

Exploring PCSK9 Genetic Impact on Lipoprotein(a) via Dual Approaches: Association and Mendelian Randomization

Previous investigations have suggested an association between the PCSK9 common polymorphism E670G and Lipoprotein(a) (Lp(a)) levels, as well as a link between plasma PCSK9 levels and Lp(a) concentrations. However, the causal relationship between plasma PCSK9 and Lp(a) levels remains uncertain. In this study, we explored the association between PCSK9 E670G polymorphism and Lp(a) levels in 614 healthy Taiwanese individuals. Employing a two-sample Mendelian randomization (MR) analysis using openly accessible PCSK9 and Lp(a) summary statistics from the genome-wide association studies (GWAS) and UK Biobank, we aimed to determine if a causal link exists between plasma PCSK9 levels and Lp(a) concentrations. Our findings reveal that the E670G G allele is independently associated with a decreased likelihood of developing elevated Lp(a) levels. This association persists even after adjusting for common cardiovascular risk factors and irrespective of lipid profile variations. The MR analysis, utilizing six PCSK9 GWAS-associated variants as instrumental variables to predict plasma PCSK9 levels, provides compelling evidence of a causal relationship between plasma PCSK9 levels and Lp(a) concentration. In conclusion, our study not only replicates the association between the PCSK9 E670G polymorphism and Lp(a) levels but also confirms a causative relationship between PCSK9 levels and Lp(a) concentrations through MR analysis.

A Novel KCNH2 S981fs Mutation Identified by Whole-Exome Sequencing Is Associated with Type 2 Long QT Syndrome

KCNH2 loss-of-function mutations cause long QT syndrome type 2 (LQT2), an inherited cardiac disorder associated with life-threatening ventricular arrhythmia. Through whole-exome sequencing, we discovered a novel AGCGACAC deletion (S981fs) in the hERG gene of an LQT2 patient. Using a heterologous expression system and patch clamping, we found that the mutant K channel had reduced cell surface expression and lower current amplitude compared to the wild type. However, functional expression was restored by lowering temperature and using potassium channel inhibitors or openers (E4031, cisapride, nicorandil). Co-immunoprecipitation experiments confirmed the assembly of mutant proteins with wild-type hERG. Confocal imaging showed decreased hERG distribution on the cell membrane in cells expressing S981fs. Notably, treatment with G418 significantly increased hERG current in wild-type/S981fs heterozygotes. In conclusion, our study identifies a novel hERG mutation leading to impaired Kv11.1 function due to trafficking and nonsense-mediated RNA decay defects. These findings shed light on the mechanisms underlying LQT2 and offer potential therapeutic avenues.

Osteopontin mediation of disturbed flow-induced endothelial mesenchymal transition through CD44 is a novel mechanism of neointimal hyperplasia in arteriovenous fistulae for hemodialysis access

In dysfunctional arteriovenous fistulae (AVF) for hemodialysis access, neointimal hyperplasia (NH) is prone to occur in the region exposed to disturbed flow. We hypothesized that disturbed flow contributes to NH in AVF by inducing endothelial mesenchymal transition (EndMT) through activation of the osteopontin/CD44 axis. In rats with aortocaval fistula, a rodent model of AVF, we demonstrated development of EndMT and expression of osteopontin and CD44 specifically in the vicinity of the arteriovenous junction using immunostaining. Duplex scan confirmed this region was exposed to a disturbed flow. A mixed ultrastructural phenotype of endothelium and smooth muscle cells was found in luminal endothelial cells of the arteriovenous junction by electron microscopy ascertaining the presence of EndMT. Endothelial lineage tracing using Cdh5-Cre/ERT2;ROSA26-tdTomato transgenic mice showed that EndMT was involved in NH of AVF since the early stage and that the endothelial-derived cells contributed to 24% of neointimal cells. In human umbilical vein endothelial cells (HUVECs) in culture, osteopontin treatment induced EndMT, which was suppressed by CD44 knockdown. Exposure to low oscillatory wall shear stress using a parallel-plate system induced EndMT in HUVECs, also suppressed by osteopontin or CD44 knockdown. In AVF of CD44 knockout mice, EndMT was mitigated and NH decreased by 35% compared to that in wild-type mice. In dysfunctional AVF of patients with uremia, expressions of osteopontin, CD44, and mesenchymal markers in endothelial cells overlying the neointima was also found by immunostaining. Thus, the osteopontin/CD44 axis regulates disturbed flow-induced EndMT, plays an important role in neointimal hyperplasia of AVF, and may act as a potential therapeutic target to prevent AVF dysfunction.

Differential Effects of ABCG5/G8 Gene Region Variants on Lipid Profile, Blood Pressure Status, and Gallstone Disease History in Taiwan

ABCG5 and ABCG8 are two key adenosine triphosphate-binding cassette (ABC) proteins that regulate whole-body sterol trafficking. This study aimed to elucidate the association between ABCG5/G8 gene region variants and lipid profile, cardiometabolic traits, and gallstone disease history in Taiwan. A total of 1494 Taiwan Biobank participants with whole-genome sequencing data and 117,679 participants with Axiom Genome-Wide CHB Array data were enrolled for analysis. Using genotype-phenotype and stepwise linear regression analyses, we found independent associations of four Asian-specific ABCG5 variants, rs119480069, rs199984328, rs560839317, and rs748096191, with total, low-density lipoprotein (LDL), and non-high-density lipoprotein (HDL) cholesterol levels (all p ≤ 0.0002). Four other variants, which were in nearly complete linkage disequilibrium, exhibited genome-wide significant associations with gallstone disease history, and the ABCG8 rs11887534 variant showed a trend of superiority for gallstone disease history in a nested logistic regression model (p = 0.074). Through regional association analysis of various other cardiometabolic traits, two variants of the PLEKHH2, approximately 50 kb from the ABCG5/G8 region, exhibited significant associations with blood pressure status (p < 10^-6). In conclusion, differential effects of ABCG5/G8 region variants were noted for lipid profile, blood pressure status, and gallstone disease history in Taiwan. These results indicate the crucial role of individualized assessment of ABCG5/G8 variants for different cardiometabolic phenotypes.

Outcomes of Percutaneous Coronary Interventions for Long Diffuse Coronary Artery Disease with Extremely Small Diameter

BACKGROUND

The optimal percutaneous coronary intervention (PCI) strategy and clinical outcomes of long lesions with an extremely small residual lumen remain unclear. This study aimed to assess the efficacy of a modified stenting strategy for diffuse coronary artery disease (CAD) with an extremely small distal residual lumen.

METHODS

736 Patients who received PCI using second-generation drug-eluting stents (DES) ≥38 mm long were retrospectively included and categorized into an extremely small distal vessel (ESDV) group (≤2.0 mm) and a non-ESDV group (>2.0 mm) according to the maximal luminal diameter of the distal vessel (dsD_Max). A modified stenting technique was applied by landing an oversized DES in the distal segment with the largest luminal diameter and maintaining the distal stent edge partially expanded.

RESULTS

The mean dsD_Max and stent lengths were 1.7 ± 0.3 mm and 62.6 ± 18.1 mm in the ESDV group and 2.7 ± 0.5 mm and 59.1 ± 16.0 mm in non-ESDV groups, respectively. The acute procedural success rate was high in both the ESDV and non-ESDV groups (95.8% and 96.5%, p = 0.70) with rare distal dissection (0.3% and 0.5%, p = 1.00). The target vessel failure (TVF) rate was 16.3% in the ESDV group and 12.1% in the non-ESDV group at a median follow-up of 65 months without significant differences after propensity score matching.

CONCLUSIONS

PCI using contemporary DES with this modified stenting technique is effective and safe for diffuse CAD with extremely small distal vessels.

Upregulation of Myocardial Neutrophil Gelatinase-Associated Lipocalin during Development of Heart Failure Caused by Volume-Overload and the Effect in Regulating Activity of Matrix Metalloproteinase-9

BACKGROUND

In patients with heart failure (HF), circulating neutrophil gelatinase-associated lipocalin (NGAL) level is increased, which is considered to be a predictor of mortality or renal outcomes. The expression of NGAL in the heart and kidney and its role in HF remain unclear.

METHODS

Aortocaval fistula was created in rats as a model of volume overload (VO)-induced HF.

RESULTS

During the development of HF, NGAL expression was upregulated in the heart but not in the kidney at both transcriptional and translational levels in the compensatory and HF phases, with a similar level in both phases. Cardiomyocytes were identified as the cell type responsible for NGAL expression. Consistent with the myocardial NGAL expression pattern, the plasma NGAL level was increased in both phases, and the level was not significantly different between both phases. We demonstrated the presence of a matrix metalloproteinase (MMP)-9/NGAL complex in cultured medium of cardiomyocytes isolated from volume-overloaded hearts by gelatin zymography. Formation of MMP-9/NGAL complex was shown to enhance the enzymatic activity of MMP-9. We found that early growth response (Egr)-1 was upregulated in the heart in both compensatory and HF phases. In neonatal cardiomyocytes, Egr-1 overexpression induced the gene expression of NGAL, which was dose-dependently suppressed by an interleukin-1 receptor antagonist.

CONCLUSIONS

During the development of HF due to VO, NGAL was upregulated in the heart but not in the kidney in both compensatory and HF phases, with a similar expression level. Myocardial NGAL upregulation enhanced MMP-9 activity through formation of the MMP-9/NGAL complex. The expression of myocardial NGAL was regulated by Egr-1.

Genetic Variants at the APOE Locus Predict Cardiometabolic Traits and Metabolic Syndrome: A Taiwan Biobank Study

Several apolipoprotein genes are located at the APOE locus on chromosome 19q13.32. This study explored the genetic determinants of cardiometabolic traits and metabolic syndrome at the APOE locus in a Taiwanese population. A total of 81,387 Taiwan Biobank (TWB) participants were enrolled to undergo genotype−phenotype analysis using data from the Axiom Genome-Wide CHB arrays. Regional association analysis with conditional analysis revealed lead single-nucleotide variations (SNVs) at the APOE locus: APOE rs7412 and rs429358 for total, low-density lipoprotein (LDL), and high-density lipoprotein (HDL) cholesterol levels; CLPTM1 rs3786505 and rs11672748 for LDL and HDL cholesterol levels; and APOC1 rs438811 and APOE-APOC1 rs439401 for serum triglyceride levels. Genotype−phenotype association analysis revealed a significant association of rs429358 and rs438811 with metabolic syndrome and of rs7412, rs438811, and rs439401 with serum albumin levels (p < 0.0015). Stepwise regression analysis indicated that CLPTM1 variants were independently associated with LDL and HDL cholesterol levels (p = 3.10 × 10−15 for rs3786505 and p = 1.48 × 10−15 for rs11672748, respectively). APOE rs429358 and APOC1 rs438811 were also independently associated with metabolic syndrome (p = 2.29 × 10−14) and serum albumin levels (p = 3.80 × 10−6), respectively. In conclusion, in addition to APOE variants, CLPTM1 is a novel candidate locus for LDL and HDL cholesterol levels at the APOE gene region in Taiwan. Our data also indicated that APOE and APOC1 variants were independently associated with metabolic syndrome and serum albumin levels, respectively. These results revealed the crucial role of genetic variants at the APOE locus in predicting cardiometabolic traits and metabolic syndrome.

Synergistic Effects of Weighted Genetic Risk Scores and Resistin and sST2 Levels on the Prognostication of Long-Term Outcomes in Patients with Coronary Artery Disease

Resistin and soluble suppression of tumorigenicity 2 (sST2) are useful predictors in patients with coronary artery disease (CAD). Their serum levels are significantly attributed to variations in RETN and IL1RL1 loci. We investigated candidate variants in the RETN locus for resistin levels and those in the IL1RL1 locus for sST2 levels and evaluated the prognostication of these two biomarkers and the corresponding variants for long-term outcomes in the patients with CAD. We included 4652, 557, and 512 Chinese participants from the Taiwan Biobank (TWB), cardiovascular health examination (CH), and CAD cohorts, respectively. Candidate variants in RETN and IL1RL1 were investigated using whole-genome sequence (WGS) and genome-wide association study (GWAS) data in the TWB cohort. The weighted genetic risk scores (WGRS) of RETN and IL1RL1 with resistin and sST2 levels were calculated. Kaplan–Meier curves were used to analyze the prognostication of resistin and sST2 levels, WGRS of RETN and IL1RL1, and their combinations. Three RETN variants (rs3219175, rs370006313, and rs3745368) and two IL1RL1 variants (rs10183388 and rs4142132) were independently associated with resistin and sST2 levels as per the WGS and GWAS data in the TWB cohort and were further validated in the CH and CAD cohorts. In combination, these variants explained 53.7% and 28.0% of the variation in resistin and sST2 levels, respectively. In the CAD cohort, higher resistin and sST2 levels predicted higher rates of all-cause mortality and major adverse cardiac events (MACEs) during long-term follow-up, but WGRS of RETN and IL1RL1 variants had no impact on these outcomes. A synergistic effect of certain combinations of biomarkers with RETN and IL1RL1 variants was found on the prognostication of long-term outcomes: Patients with high resistin levels/low RETN WGRS and those with high sST2 levels/low IL1RL1 WGRS had significantly higher all-cause mortality and MACEs rates, and those with both these combinations had the poorest outcomes. Both higher resistin and sST2 levels, but not RETN and IL1RL1 variants, predict poor long-term outcomes in patients with CAD. Furthermore, combining resistin and sST2 levels with the WGRS of RETN and IL1RL1 genotyping exerts a synergistic effect on the prognostication of CAD outcomes. Future studies including a large sample size of participants with different ethnic populations are needed to verify this finding.

Differential Genetic and Epigenetic Effects of the KLF14 Gene on Body Shape Indices and Metabolic Traits

The KLF14 gene is a key metabolic transcriptional transregulator with monoallelic maternal expression. KLF14 variants are only associated with adipose tissue gene expression, and KLF14 promoter methylation is strongly associated with age. This study investigated whether age, sex, and obesity mediate the effects of KLF14 variants and DNA methylation status on body shape indices and metabolic traits. In total, the data of 78,742 and 1636 participants from the Taiwan Biobank were included in the regional plot association analysis for KLF14 variants and KLF14 methylation, respectively. Regional plot association studies revealed that the KLF14 rs4731702 variant and the nearby strong linkage disequilibrium polymorphisms were the lead variants for lipid profiles, blood pressure status, insulin resistance surrogate markers, and metabolic syndrome mainly in female participants and for body shape indices mainly in obese women. Significant age-dependent associations between KLF14 promoter methylation levels and body shape indices, and metabolic traits were also noted predominantly in female participants. KLF14 variants and KLF14 hypermethylation status were associated with metabolically healthy and unhealthy phenotypes, respectively, in obese individuals, and only the KLF14 variants demonstrated a significant association with both higher adiposity and lower cardiometabolic risk in the same allele, revealing uncoupled excessive adiposity from its cardiometabolic comorbidities, especially in obese women. Variations of KLF14 are associated with body shape indices, metabolic traits, insulin resistance, and metabolically healthy status. Differential genetic and epigenetic effects of KLF14 are age-, sex- and obesity-dependent. These results provided a personalized reference for the management of cardiometabolic diseases in precision medicine.

Pleiotropic Effects of Common and Rare GCKR Exonic Mutations on Cardiometabolic Traits

Background: The common non-synonymous mutation of the glucokinase regulator (GCKR) gene, namely rs1260326, is widely reported to have pleiotropic effects on cardio-metabolic traits and hematological parameters. Objective: This study aimed to identify whether other GCKR variants may have pleiotropic effects independent of the rs1260326 genotypes. Methods: In total, 81,097 Taiwan Biobank participants were enrolled for the regional plot association studies and candidate variant analysis of the region around the GCKR gene. Results: The initial candidate variant approach showed the significant association of the rs1260326 genotypes with multiple phenotypes. Regional plot association analysis of the GCKR gene region further revealed genome-wide significant associations between GCKR variants and serum total and low-density lipoprotein cholesterol; triglyceride, uric acid, creatinine, aspartate aminotransferase, γ-Glutamyl transferase, albumin, and fasting plasma glucose levels; estimated glomerular filtration rate; leukocyte and platelet counts; microalbuminuria, and metabolic syndrome, with rs1260326 being the most common lead polymorphism. Serial conditional analysis identified genome-wide significant associations of two low-frequency exonic mutations, rs143881585 and rs8179206, with high serum triglyceride and albumin levels. In five rare GCKR exonic non-synonymous or nonsense mutations available for analysis, GCKR rs146175795 showed an independent association with serum triglyceride and albumin levels and rs150673460 showed an independent association with serum triglyceride levels. Weighted genetic risk scores from the combination of GCKR rs143881585 and rs146175795 revealed a significant association with metabolic syndrome. Conclusion: In addition to the rs1260326 variant, low-frequency and rare GCKR exonic mutations exhibit pleiotropic effects on serum triglyceride and albumin levels and the risk of metabolic syndrome. These results provide evidence that both common and rare GCKR variants may play a critical role in predicting the risk of cardiometabolic disorders.

Procedural and One-Year Clinical Outcomes of Long 48 mm Xience Xpedition Everolimus-Eluting Stent in Complex Long Diffuse Coronary Artery Lesions

BACKGROUND AND OBJECTIVES

Long 48 mm drug-eluting stents (DES) used to treat long coronary lesions decreases the number of stents needed and avoids stent overlapping. Disadvantages include difficulty in delivery and size discrepancy between proximal and distal stent landing zones. The present study analyzed the rate of procedural, immediate angiographic, and 1-year clinical outcomes of long diffuse coronary artery lesions treated with 48 mm everolimus-eluting stents (EES) and compared the clinical outcomes with multiple overlapping DES.

METHODS

This retrospective analysis included 213 patients with 228 lesions treated with at least one 48 mm EES at 2 hospitals in Taiwan.

RESULTS

About 40.4% of the lesions had moderate-severe calcification and 20.2% had acute angulation. The mean lesion length was 49.2 ± 18.1 mm. In 161 lesions requiring a single 48 mm EES, 67.1% had a discrepancy between proximal and distal reference diameter of ≥0.5 mm and 36% had a discrepancy of ≥1.0 mm. The procedural success rate was 98.6%. Target-vessel failure (TVF) rate at 1 year was 4.2%. Cardiac death occurred in 3 patients. The rates of target-vessel myocardial infarction (TV-MI), target-vessel revascularization (TVR) and definite/ probable stent thrombosis were 1.4%, 3.3%, and 0.9%, respectively. After adjusting patient variables by propensity score matching, no significant difference was found for cardiac death, TVF, TV-MI, and clinically driven TVR.

CONCLUSION

Use of 48 mm EES to treat long coronary lesions in clinically and anatomically complex patients is safe and effective. In the propensity score-matched analysis, the 48 mm EES and multiple stents have comparable clinical outcomes.

Circulating serum amyloid A levels but not SAA1 variants predict long-term outcomes of angiographically confirmed coronary artery disease

Objectives

Circulating serum amyloid A (SAA) levels are strongly associated with atherosclerotic cardiovascular disease risk and severity. The association between SAA1 genetic variants, SAA levels, inflammatory marker levels, and coronary artery disease (CAD) prognosis has not been fully understood.

Materials and Methods

In total, 2199 Taiwan Biobank (TWB) participants were enrolled for a genome-wide association study (GWAS), and the long-term outcomes in 481 patients with CAD were analyzed. The primary endpoint was all-cause mortality, and the secondary endpoint was the combination of all-cause death, myocardial infarction, stroke, and hospitalization for heart failure.

Results

Through GWAS, SAA1 rs11024600 and rs7112278 were independently associated with SAA levels (P = 3.84 × 10^-145 and P = 1.05 × 10^-29, respectively). SAA levels were positively associated with leukocyte counts and multiple inflammatory marker levels in CAD patients and with body mass index, hemoglobin, high-density lipoprotein cholesterol, and alanine aminotransferase levels in TWB participants. By stepwise linear regression analysis, SAA1 gene variants contributed to 27.53% and 8.07% of the variation of the SAA levels in TWB and CAD populations, respectively, revealing a stronger influence of these two variants in TWB participants compared to CAD patients. Kaplan-Meier survival analysis revealed that SAA levels, but not SAA1 gene variants, were associated with long-term outcomes in patients with CAD. Cox regression analysis also indicated that high circulating SAA levels were an independent predictor of both the primary and secondary endpoints.

Conclusion

SAA1 genotypes contributed significantly to SAA levels in the general population and in patients with CAD. Circulating SAA levels but not SAA1 genetic variants could predict long-term outcomes in patients with angiographically confirmed CAD.

Pharmacological Activation Of Aldehyde Dehydrogenase 2 Protects Against Heatstroke-Induced Acute Lung Injury by Modulating Oxidative Stress and Endothelial Dysfunction

Heatstroke (HS) can cause acute lung injury (ALI). Heat stress induces inflammation and apoptosis via reactive oxygen species (ROS) and endogenous reactive aldehydes. Endothelial dysfunction also plays a crucial role in HS-induced ALI. Aldehyde dehydrogenase 2 (ALDH2) is a mitochondrial enzyme that detoxifies aldehydes such as 4-hydroxy-2-nonenal (4-HNE) protein adducts. A single point mutation in ALDH2 at E487K (ALDH2*2) intrinsically lowers the activity of ALDH2. Alda-1, an ALDH2 activator, attenuates the formation of 4-HNE protein adducts and ROS in several disease models. We hypothesized that ALDH2 can protect against heat stress-induced vascular inflammation and the accumulation of ROS and toxic aldehydes. Homozygous ALDH2*2 knock-in (KI) mice on a C57BL/6J background and C57BL/6J mice were used for the animal experiments. Human umbilical vein endothelial cells (HUVECs) were used for the in vitro experiment. The mice were directly subjected to whole-body heating (WBH, 42°C) for 1 h at 80% relative humidity. Alda-1 (16 mg/kg) was administered intraperitoneally prior to WBH. The severity of ALI was assessed by analyzing the protein levels and cell counts in the bronchoalveolar lavage fluid, the wet/dry ratio and histology. ALDH2*2 KI mice were susceptible to HS-induced ALI in vivo. Silencing ALDH2 induced 4-HNE and ROS accumulation in HUVECs subjected to heat stress. Alda-1 attenuated the heat stress-induced activation of inflammatory pathways, senescence and apoptosis in HUVECs. The lung homogenates of mice pretreated with Alda-1 exhibited significantly elevated ALDH2 activity and decreased ROS accumulation after WBH. Alda-1 significantly decreased the WBH-induced accumulation of 4-HNE and p65 and p38 activation. Here, we demonstrated the crucial roles of ALDH2 in protecting against heat stress-induced ROS production and vascular inflammation and preserving the viability of ECs. The activation of ALDH2 by Alda-1 attenuates WBH-induced ALI in vivo.

Genome-wide association study revealed novel candidate gene loci associated with soluble E-selectin levels in a Taiwanese population

BACKGROUND AND AIMS

Increase soluble E-selectin (sE-selectin) levels are associated with various inflammation and cardiometabolic disorders.

METHODS

This study aimed to investigate the genetic determinants of circulating sE-selectin levels by genome-wide association study (GWAS) in 4,525 Taiwan Biobank (TWB) participants and genotype-phenotype association analysis for sE-selectin level-determining alleles in over 80,000 TWB participants.

RESULTS

By GWAS, ABO, SELE, and FUT6 gene variants were identified as the determinants of sE-selectin levels, which reach genome-wide significance (maximum p = 3.25 × 10-271, 4.81 × 10-14, and 9.64 × 10-12, respectively). After further adjustment for the lead ABO rs2519093 genotypes, three novel gene loci, EVI5, FER and DMAC1, were associated with sE-selectin levels at p < 5 × 10-7. Three other previously reported gene loci, CELSR2, ST3GAL6-AS1, and HNF1A-AS1, also showed supportive evidence for the association with sE-selectin levels (maximum p < 0.0073). A multivariate analysis revealed age, body mass index, current smoking, hemoglobin A1C, hematocrit, leukocyte and platelet counts, serum alanine aminotransferase, triglycerides, and uric acid levels were independently associated with sE-selectin levels, in which the above ten gene loci contribute to 27.68% of the variance. For genotype-phenotype association analysis, a pleiotropic effect was demonstrated with genome-wide significant association between ABO gene variants and total and low-density-lipoprotein cholesterol levels, leukocyte counts and hematocrit.

CONCLUSIONS

Our data provide novel insight into the regulation of sE-selectin levels. These results may open new avenues in understanding the critical role of E-selectin on the pathogenesis of inflammatory and cardiometabolic disorders.

Circulating chemerin level is associated with metabolic, biochemical and haematological parameters-A population-based study

OBJECTIVE

This study aims to analyse the association of chemerin levels with several metabolic, biochemical and haematological parameters in a large Taiwanese population with relative healthy status.

DESIGN

Cross-sectional study.

METHODS

Data of 4101 healthy participants without history of hypertension, diabetes, dyslipidaemia and renal insufficiency from Taiwan Biobank were analysed. The demographic, biochemical and haematologic parameters were retrieved from the database. Chemerin levels were measured using commercially available enzyme-linked immunosorbent assay. Univariate and multivariate analysis was performed to test the independent correlates of chemerin.

RESULTS

In the univariate analysis, circulating chemerin levels were positively associated with body mass index (BMI), waist circumference, waist-to-hip ratio (WHR), systolic (SBP) and diastolic blood pressure (DBP), haemoglobin A1C (HbA1C), total cholesterol, triglyceride, low-density lipoprotein cholesterol (LDL-C), creatinine, uric acid, alanine aminotransferase (ALT), gamma-glutamyl transferase (γ-GT), leucocyte and platelet counts both in men and women and negatively associated with high-density lipoprotein cholesterol (HDL-C), estimated glomerular filtration rate (eGFR) and total bilirubin. In the multivariate analysis, BMI, HbA1C, triglyceride, uric acid, γ-GT and platelet counts predicted chemerin levels independently both in men and in women with positive correlation, while eGFR, total bilirubin and HDL-C predicted circulating chemerin levels independently with negative correlation.

CONCLUSIONS

Chemerin level is independently associated with multiple metabolic, biochemical and haematological parameters. This study provides further evidence on the molecular basis linking obesity with several human diseases.

Circulating chemerin levels are determined through circulating platelet counts in nondiabetic Taiwanese people: A bidirectional Mendelian randomization study

BACKGROUND AND AIMS

Platelet count (PLT) is a predictor of metabolic and inflammation-related disorders. Platelets can release prochemerin, which acts as a link between coagulation and inflammation and between innate and adaptive immunity. The causal effect between PLT and circulating chemerin level has not been elucidated.

METHODS

Nondiabetic participants with samples in the Taiwan Biobank were recruited for a genome-wide association study (GWAS) based on PLT (17,037 participants) and chemerin levels (3887 participants). A bidirectional Mendelian randomization (MR) study was conducted to determine the association between circulating PLT and chemerin levels.

RESULTS

For a GWAS of PLT, 11 gene loci were found to have genome-wide significance. For a GWAS of chemerin levels, two gene loci, RARRES2 and HLADQA2-HLADQB1, were found to have genome-wide significance. Age, sex, body mass index, leukocyte count, hemoglobin, mean blood pressure, hemoglobin A1C, serum total bilirubin, aspartate aminotransferase, triglyceride, and low-density-lipoprotein cholesterol levels, estimated glomerular filtration rate, and circulating chemerin level were found to be independently associated with PLT through a stepwise regression analysis. A bidirectional MR study revealed weighted genetic risk scores (WGRSs) for PLT were significantly associated with chemerin levels by using a two-stage least-square method in a multivariate analysis (p = 0.0031), and no significant association between chemerin level WGRSs and PLT was noted. Sensitivity analysis further revealed no violation of the exclusion-restriction assumption with PLT-determining genotypes on chemerin levels.

CONCLUSIONS

Through a bidirectional MR analysis, our data revealed that chemerin levels were determined based on circulating PLT. Circulating chemerin levels can be intermediates between PLT and future metabolic and inflammation-related disorders.

Aldehyde dehydrogenase 2 protects against abdominal aortic aneurysm formation by reducing reactive oxygen species, vascular inflammation, and apoptosis of vascular smooth muscle cells

Mitochondrial aldehyde dehydrogenase 2 (ALDH2) is an enzyme that detoxifies aldehydes by converting them to carboxylic acids. ALDH2 deficiency is known to increase oxidative stress. Increased oxidative stress plays a pivotal role in abdominal aortic aneurysm (AAA) pathogenesis. Reactive oxygen species (ROS) promote degradation of the extracellular matrix (ECM) and vascular smooth muscle cell (VSMC) apoptosis. Reducing oxidative stress by an ALDH2 activator could have therapeutic potential for limiting AAA development. We hypothesized that ALDH2 deficiency could increase the risk for AAA by decreasing ROS elimination and that an ALDH2 activator could provide an alternative option for AAA treatment. The National Center for Biotechnology (NCBI) Gene Expression Omnibus (GEO) database was used. Human aortic smooth muscle cells (HASMCs) were used for the in vitro experiments. Gene-targeted ALDH2*2 KI knock-in mice on a C57BL/6J background and apolipoprotein E knockout (ApoE KO) mice were obtained. An animal model of AAA was constructed using osmotic minipumps to deliver 1000 ng/kg/min angiotensin II (AngII) for 28 days. Patients with AAA had significantly lower ALDH2 expression levels than normal subjects. ALDH2*2 KI mice were susceptible to AngII administration, exhibiting significantly increased AAA incidence rates and increased aortic diameters. Alda-1, an ALDH2 activator, reduced AngII-induced ROS production, NF-kB activation, and apoptosis in HASMCs. Alda-1 attenuated AngII-induced aneurysm formation and decreased aortic expansion in ApoE KO mice. We concluded that ALDH2 deficiency is associated with the development of AAAs in humans and a murine disease model. ALDH2 deficiency increases susceptibility to AngII-induced AAA formation by attenuating anti-ROS effects and increasing VSMC apoptosis and vascular inflammation. Alda-1 was shown to attenuate the progression of experimental AAA in a murine model.

Modification effect of sex and obesity on the correlation of LEP polymorphisms with leptin levels in Taiwanese obese women

Background

Obesity has become the main health issue in developed countries as it impacts life expectancy and increases mortality of cerebrovascular or cardiovascular diseases. The leptin is one of the adipokines which presents in the serum in proportion to the amount of adipose tissue and is translated from LEP gene. It involves in energy homeostasis, lipid and glucose metabolisms, modulation of immune systems, and thermogenesis. Many previous studies have revealed controversial results between LEP polymorphisms and leptin levels in different ages and ethnicities. Herein, we investigated the impacts of LEP polymorphism against leptin levels in Taiwanese subjects.

Methods

In 599 Taiwanese subjects, excluding clinically overt systemic disease, age below 18 years old, and C‐reactive protein (CRP) level of above 10 mg/L, few of LEP polymorphisms were genotyped with TaqMan SNP genotyping assays, were further analyzed for association with leptin level in univariate and multivariate linear regression analyses with Bonferroni correction for multiple tests in stratified groups. The univariate and stepwise multivariate linear regression analyses were performed to determine the coefficient of determinant of LEP polymorphisms over leptin level.

Results

Significant associations were found between LEP polymorphisms and leptin levels in obese women. Circulating leptin level was positively correlated with inflammatory, insulin resistance markers, and visceral obesity markers in all subjects. Furthermore, stratified and interaction analyses revealed that LEP polymorphisms, rs7799039 and rs2167270, were significantly associated with leptin levels in obese women—8%–10% of which could be explained by LEP polymorphisms.

Conclusion

The LEP polymorphisms are independently associated with leptin levels in Taiwanese obese women. Further, the genetic determinants for leptin levels may be different between obese and nonobese, and in different sex individuals. The obesity status and female sex may exert modification effect on transcription of LEP, particularly in obese women.

Osteoprotegerin and osteopontin levels, but not gene polymorphisms, predict mortality in cardiovascular diseases

Aim: This study aims to investigate whether osteoprotegerin (OPG) or osteopontin (OPN) single nucleotide polymorphisms (SNPs) will predict survival. Materials & methods: This study enrolled 617 participants undergoing health examination, 536 coronary artery disease (CAD) patients and 86 peripheral artery disease (PAD) patients. Genotypes of OPG SNP rs2073618 and OPN SNP rs11730582 were determined. OPG and OPN levels were measured. Results: In both CAD and PAD populations, high OPG and OPN levels were strong predictors of all-cause death. The OPG rs2073618 CC genotype and the OPN rs11730582 TT genotype did not predict mortality. Conclusion: High OPG and high OPN levels, but not OPG rs2073618 CC genotype or OPN rs11730582 TT genotype, were strong predictors of mortality in both CAD and PAD patients.

Pleiotropic association of LIPC variants with lipid and urinary 8-hydroxy deoxyguanosine levels in a Taiwanese population

BACKGROUND

Hepatic lipase (HL, encoded by LIPC) is a glycoprotein primarily synthesized and secreted by hepatocytes. Previous studies had demonstrated that HL is crucial for reverse cholesterol transport and affects the metabolism, composition, and level of several lipoproteins. In current study, we investigated the association of LIPC (Lipase C, Hepatic Type) variants with circulating and urinary biomarker levels by using subgroup and mediation analyses.

METHODS

A total of 572 participants from Taiwan were genotyped for three LIPC single nucleotide polymorphisms (SNPs) by using TaqMan assay. Fasting levels of glucose, lipid profile, inflammation markers, urine creatinine and 8-hydroxy deoxyguanosine (8-OHdG) were measured. The chi-square test, 2-sample t test and Analysis of variance (ANOVA) were used to examine differences among variables and genotype frequencies.

RESULTS

SNPs rs2043085 and rs1532085 were significantly associated with urinary 8-OHdG levels, whereas all three SNPs were more significantly associated with Triglycerides (TG) or HDL-cholesterol (HDL-C) levels after additional adjustment for HDL-C or TG levels, respectively. Subgroup analyses revealed that the association of the LIPC SNPs with the levels of serum TG, HDL-C, and urinary 8-OHdG were predominantly observed in the men but not in the women. Differential associations of the LIPC SNPs with various lipid levels were observed in participants with different adiposity statuses. Mediation analyses indicated that TG levels acted as a suppressor masking the association of the LIPC genotypes with HDL-C levels, particularly in the men (Sobel test, all P < 0.01).

CONCLUSION

Our data revealed that interaction and suppression effects mediated the pleiotropic association of the LIPC variants. The effects of the LIPC SNPs depended on sex, adiposity status, and TG levels. Thus, our findings can provide a method for identifying high-risk populations of cardiovascular diseases for clinical diagnosis.

Hypersensitivity and Cardiovascular Risks Related to Allopurinol and Febuxostat Therapy in Asians: A Population-Based Cohort Study and Meta-Analysis

The safety of newer xanthine oxidase inhibitor febuxostat compared to allopurinol remains unclear. To compare the risks of allopurinol hypersensitivity and febuxostat hypersensitivity and cardiovascular diseases (CVDs) in Asians, we conducted a population-based cohort study enrolling patients receiving allopurinol or febuxostat from Chang Gung Memorial Hospital Health System across Taiwan during 2012-2016 and further performed a meta-analysis incorporating two recent studies. Among the 61,539 users, a corresponding 12,007 and 5,680 patients were identified as new users. The overall incidence of febuxostat hypersensitivity was significantly lower than allopurinol hypersensitivity (0.2 vs. 2.7 per 1,000 new users; P < 0.001). There were 33 allopurinol-hypersensitivity reactions (including 18 severe cutaneous adverse drug reactions), and only one patient developed febuxostat-maculopapular exanthema. Moreover, febuxostat did not statistically increase the risk of CVD (hazard ratio (HR), 1.16; P = 0.152) and related death (HR, 1.49; P = 0.496) compared to allopurinol. The result of the meta-analysis also showed a consistent result. In conclusion, the incidence and severity of febuxostat-hypersensitivity are lower than with allopurinol. Febuxostat did not show an increased risk of CVD and related death.

Circulating Chemerin Levels, but not the RARRES2 Polymorphisms, Predict the Long-Term Outcome of Angiographically Confirmed Coronary Artery Disease

Chemerin, a novel adipokine, has been associated with metabolic, inflammatory, and atherosclerotic diseases. We aimed to determine the genetic basis of chemerin levels by conducting a genome-wide association study (GWAS) and to investigate the role of RARRES2 polymorphisms and circulating chemerin levels in the long-term outcome of coronary artery disease (CAD). A total of 2197 participants from the Taiwan Biobank (TWB) were recruited for the GWAS analysis, and 481 patients with angiographically confirmed CAD were enrolled for long-term outcome analysis. One locus of genome-wide significance with a single independent association signal was identified in the GWAS for chemerin levels with the peak association at the RARRES2 gene promoter region polymorphism rs3735167 (p = 2.35 × 10⁻²¹). In the CAD population, borderline significance was noted between RARRES2 polymorphisms and chemerin levels, whereas high chemerin levels were associated with obesity, female sex, diabetes mellitus, hypertension, current smoking, high platelet and leukocyte counts, anemia, impaired renal function, high C-reactive protein (CRP) levels, and multi-vessel disease. Kaplan–Meier survival curves indicated that the patients with high chemerin and CRP levels, but not those with RARRES2 polymorphisms, had a lower survival rate and higher combined cerebral and cardiovascular event rates. Combined chemerin and CRP levels further revealed a stepwise increase in poor clinical outcomes from low- to high-risk subgroups. In conclusion, rs3735167 is the lead RARRES2 polymorphism for chemerin levels in Taiwanese. Chemerin levels, but not the rs3735167 genotypes, predicted the long-term outcome of CAD, especially when combined with CRP levels.

Outcomes of Pulmonary Endarterectomy for Chronic Thromboembolic Pulmonary Hypertension at a Single Center in Taiwan

BACKGROUND

Chronic thromboembolic pulmonary hypertension (CTEPH) is classified as group IV pulmonary hypertension. This study aimed to report our institutional experience in managing CTEPH.

METHODS

We prospectively collected the data of 23 patients diagnosed with CTEPH between August 2001 and August 2017 in Linkou Chang Gung Memorial Hospital. Baseline characteristics including functional class (FC), 6-minute walk distance (6MWD), comorbidities, hematological and biochemical data, echocardiography, cardiac catheterization, and selective pulmonary angiography were recorded at diagnosis. All patients were referred to a cardiac surgeon for pulmonary endarterectomy (PEA) assessment.

RESULTS

The mean age at diagnosis was 48.4 ± 16.1 years. Nineteen patients (83%) underwent PEA with mean postoperative follow-up of 37.7 ± 42.8 months. The in-hospital mortality rate of PEA was 11%. The 1-, 2-, 3- and 5-year overall survival rates were 89%, 89%, 81%, and 50%, respectively. After 3 months of PEA, all patients had improvements in FC, 6MWD (from 326 ± 62 to 420 ± 63 m), B-type natriuretic peptide level (from 602 ± 599 to 268 ± 565 pg/mL), and systolic pulmonary artery pressure (from 79 ± 19 to 48 ± 19 mmHg). The patients with proximal disease (Jamieson type 1 or 2) had better survival than those with distal disease (Jamieson type 3 or 4), but there was no significant difference in mortality between FC III and IV. All of the four patients who did not undergo PEA survived for more than 3 years.

CONCLUSIONS

Significant improvements in symptoms, functional capacity, and hemodynamics were achieved in the CTEPH patients after PEA. However, the overall survival was still unsatisfactory.

Combined effect of acid-sensing ion channel 3 and transient receptor potential vanilloid 1 gene polymorphisms on blood pressure variations in Taiwanese

Objectives:

Both acid-sensing ion channel acid-sensing ion channel 3 (ASIC3) and transient receptor potential vanilloid 1 (TRPV1) have been proposed to be involved in the pathophysiology of hypertension. Common colocalization of ASIC3 and TRPV1 channels in the same sensory neuron has been reported. We aimed to study the combined ASIC3 and TRPV1 gene polymorphisms in the risk of hypertension.

Materials and Methods:

To test the statistical association between genetic polymorphisms of the ASIC3 and TRPV1 genes and blood pressure (BP) variations in Taiwanese, 551 unrelated individuals (286 men and 265 women) having routine health examinations were recruited. The participants had no history of cardiovascular disease or use of medication for hypertension.

Results:

Six ASIC3 and four TRPV1 gene polymorphisms were genotyped, and only the ASIC3 rs2288646 polymorphism was associated with variations in BP in the participants. In subgroup analysis, we found participants carrying the combined ASIC3 rs2288646 AA or AG and TRPV1 rs8065080 CC genotypes (combined genotypes) had significantly higher systolic, mean and diastolic BP compared with the other subgroups (P = 0.009, 0.003, and 0.006, respectively, after Bonferroni correction). Interaction analysis also revealed significant gene-gene interaction in the systolic, mean, and diastolic BP in the ASIC3 and TRPV1 genotypes (interaction P = 0.006, 0.002, and 0.002, respectively). A trend of increasing frequencies of the combined genotype was observed in normotensive, prehypertensive, and hypertensive subgroups (P for trend = 0.001), as well as in those with higher systolic and diastolic BPs (P for trend = 9.13 × 10⁻⁴ and P for trend = 5.5 × 10⁻⁵, respectively).

Conclusion:

Our data show a combined effect of ASIC3 and TRPV1 gene polymorphisms in BP variations in Taiwanese. These results suggest that the interaction between ASIC3 and TRPV1 is involved in BP regulation.

LIPC variants as genetic determinants of adiposity status, visceral adiposity indicators, and triglyceride-glucose (TyG) index-related parameters mediated by serum triglyceride levels

BACKGROUND

Visceral adiposity indicators and the product of triglyceride and fasting plasma glucose (TyG) index-related parameters are effective surrogate markers for insulin resistance (IR) and are predictors of metabolic syndrome and diabetes mellitus. However, their genetic determinants have not been previously reported. Pleiotropic associations of LIPC variants have been observed in lipid profiles and atherosclerotic cardiovascular diseases. We aimed to investigate LIPC polymorphisms as the genetic determinants of adiposity status, visceral adiposity indicators and TyG index-related parameters.

METHODS

A total of 592 participants from Taiwan were genotyped for three LIPC single nucleotide polymorphisms (SNPs).

RESULTS

The LIPC SNPs rs2043085 and rs1532085 were significantly associated with body mass index (BMI), waist circumference (WC), lipid accumulation product, visceral adiposity index, and TyG index-related parameters [including the TyG index, TyG with adiposity status (TyG-BMI), and TyG-WC index], whereas the rs1800588 SNP was only significantly associated with the TyG index. The associations became nonsignificant after further adjustment for serum TG levels. No significant association was observed between any the studied LIPC SNPs and IR status.

CONCLUSION

Our data revealed a pleiotropic association between the LIPC variants and visceral adiposity indicators and TyG index-related parameters, which are mediated by serum TG levels.

A GDF15 3' UTR variant, rs1054564, results in allele-specific translational repression of GDF15 by hsa-miR-1233-3p

Growth differentiation factor 15 (GDF15) is a strong predictor of cardiovascular events and mortality in individuals with or without cardiovascular diseases. Single nucleotide polymorphisms (SNPs) in microRNA (miRNA) target sites, also known as miRSNPs, are known to enhance or weaken miRNA-mRNA interactions and have been linked to diseases such as cardiovascular disease and cancer. In this study, we aimed to elucidate the functional significance of the miRSNP rs1054564 in regulating GDF15 levels. Two rs1054564-containing binding sites for hsa-miR-873-5p and hsa-miR-1233-3p were identified in the 3′ untranslated region (UTR) of the GDF15 transcript using bioinformatics tools. Their activities were further characterized by in vitro reporter assays. Bioinformatics prediction suggested that miRNA binding sites harboring the rs1054564-G allele had lower free energies than those with the C allele and therefore were better targets with higher affinities for both hsa-miR-873-5p and hsa-miR-1233-3p. Reporter assays showed that luciferase activity was significantly decreased by rs1054564-G-containing 3′ UTRs for both miRNAs (P < 0.05) and was restored by miRNA inhibitors. Comparing the fold suppression of the two miRNAs, only that of hsa-miR-1233-3p showed significant changes between the rs1054564-G- and C-containing 3′ UTRs (P = 0.034). In addition, western blots showed that transfection of both miRNA mimics significantly decreased endogenous GDF15 expression in a melanoma cell line (P < 0.05). Taken together, our findings demonstrate that GDF15 is a target of hsa-miR-873-5p and hsa-miR-1233-3p and that the rs1054564-C allele partially abolishes hsa-miR-1233-3p-mediated translational suppression of GDF15. These results suggest that rs1054564 confers allele-specific translational repression of GDF15 via hsa-miR-1233-3p. Our work thus provides biological insight into the previously reported clinical association between rs1054564 and plasma GDF15 levels.

Interactive effects of C-reactive protein levels on the association between APOE variants and triglyceride levels in a Taiwanese population

Background

Apolipoprotein E (APOE) plays a major role in lipid metabolism and inflammation. However, the association between APOE gene polymorphisms and serum triglyceride levels remains controversial. We tested the effects of APOE variants on triglyceride levels and their interactions with the inflammatory marker C-reactive protein (CRP) in a Taiwanese population.

Methods

Two APOE single nucleotide polymorphisms (SNPs) rs429358 and rs7412 were genotyped by TaqMan Assay using real time PCR in 595 healthy subjects attending the clinic for routine visits.

Results

After adjustment for clinical covariates, subjects carrying the rs429358-TT genotype and non-ε4 alleles were found to have higher CRP levels, whereas those with rs7412-CC genotype and non-ε2 alleles had significantly higher total and low-density lipoprotein cholesterol levels (all P < 0.01). Using subgroup and interaction analyses, we observed significantly lower triglyceride levels in subjects carrying the rs429358-TT genotype and non-ε4 alleles in the low CRP group (P = 2.71× 10⁻⁴ and P = 4.32 × 10⁻⁴, respectively), but not in those in the high CRP group (interaction P = 0.013 and 0.045, respectively). In addition, multivariate stepwise linear regression analysis showed that subjects carrying the rs429358-TT genotype and non-ε4 alleles with low CRP levels had significantly lower triglyceride levels (P < 0.001 and P < 0.001, respectively). In addition, when combined with the risk alleles of GCKR, APOA5 and LPL gene variants, we observed that triglyceride levels increased significantly with the number of risk alleles (P = 2.9 × 10⁻¹²).

Conclusions

The combination of SNPs and ε alleles at the APOE locus is involved in managing lipid and CRP levels in the Taiwanese population. APOE polymorphisms interact with CRP to regulate triglyceride levels, thus triglyceride concentration is influenced by both the genetic background of the APOE locus and the inflammatory status of a subject.

Electronic supplementary material

The online version of this article (doi:10.1186/s12944-016-0262-z) contains supplementary material, which is available to authorized users.

MMP9 Rs3918242 Polymorphism Affects Tachycardia-Induced MMP9 Expression in Cultured Atrial-Derived Myocytes but Is Not a Risk Factor for Atrial Fibrillation among the Taiwanese

Matrix metalloproteinase (MMP) plays an important role in the pathogenesis of atrial fibrillation (AF). The MMP9 promoter has a functional polymorphism rs3918242 that can regulate the level of gene transcription. This study recruited 200 AF patients and 240 controls. The MMP9 rs3918242 was examined by polymerase chain reactions. HL-1 atrial myocytes were cultured and electrically stimulated. Right atrial appendages were obtained from six patients with AF and three controls with sinus rhythm undergoing open heart surgery. The MMP9 expression and activity were determined using immunohistochemical analysis and gelatin zymography, respectively. Rapid pacing induces MMP9 secretion from HL-1 myocytes in a time- and dose-dependent manner. The responsiveness of MMP9 transcriptional activity to tachypacing was significantly enhanced by rs3918242. The expression of MMP9 was increased in fibrillating atrial tissue than in sinus rhythm. However, the distribution of rs3918242 genotypes and allele frequencies did not significantly differ between the control and AF groups. HL-1 myocyte may secrete MMP9 in response to rapid pacing, and the secretion could be modulated by rs3918242. Although the MMP9 expression of human atrial myocyte is associated with AF, our study did not support the association of susceptibility to AF among Taiwanese subjects with the MMP9 rs3918242 polymorphism.

Triglyceride Glucose-Body Mass Index Is a Simple and Clinically Useful Surrogate Marker for Insulin Resistance in Nondiabetic Individuals

Background

Insulin resistance (IR) and the consequences of compensatory hyperinsulinemia are pathogenic factors for a set of metabolic abnormalities, which contribute to the development of diabetes mellitus and cardiovascular diseases. We compared traditional lipid levels and ratios and combined them with fasting plasma glucose (FPG) levels or adiposity status for determining their efficiency as independent risk factors for IR.

Methods

We enrolled 511 Taiwanese individuals for the analysis. The clinical usefulness of various parameters—such as traditional lipid levels and ratios; visceral adiposity indicators, visceral adiposity index (VAI), and lipid accumulation product (LAP); the product of triglyceride (TG) and FPG (the TyG index); TyG with adiposity status (TyG-body mass index [BMI]) and TyG-waist circumference index [WC]); and adipokine levels and ratios—was analyzed to identify IR.

Results

For all lipid ratios, the TG/high-density lipoprotein cholesterol (HDL-C) ratio had the highest additional percentage of variation in the homeostasis model assessment of insulin resistance (HOMA-IR; 7.0% in total); for all variables of interest, TyG-BMI and leptin-adiponectin ratio (LAR) were strongly associated with HOMA-IR, with 16.6% and 23.2% of variability, respectively. A logistic regression analysis revealed similar patterns. A receiver operating characteristic (ROC) curve analysis indicated that TG/HDL-C was a more efficient IR discriminator than other lipid variables or ratios. The area under the ROC curve (AUC) for VAI (0.734) and TyG (0.708) was larger than that for TG/HDL-C (0.707). TyG-BMI and LAR had the largest AUC (0.801 and 0.801, respectively).

Conclusion

TyG-BMI is a simple, powerful, and clinically useful surrogate marker for early identification of IR.

Association of ABCG2 rs2231142-A allele and serum uric acid levels in male and obese individuals in a Han Taiwanese population

BACKGROUND/PURPOSE

Recent studies suggest that hyperuricemia is a potential risk factor for cardiovascular disease (CVD). Hyperuricemia is highly heritable and is associated with sex and body weight. Previous genome-wide association studies have found that the ABCG2 single nucleotide polymorphism (SNP) rs2231142 is an important genetic factor for increased uric acid (UA) levels, and the degree of association between rs2231142 and hyperuricemia is affected by both sex and ethnicity. This investigation aimed to analyze the association between ABCG2 polymorphisms and UA levels, as well as their interactions with sex and obesity in Taiwanese.

METHODS

Two genetic polymorphisms around the ABCG2 gene were genotyped in 459 patients.

RESULTS

After adjusting for clinical covariates, the rs2231142 SNP was found significantly associated with UA levels using a dominant inheritance model. Patients carrying the rs2231142-A allele had a higher frequency of hyperuricemia than those with the rs2231142-CC allele. Subgroup analysis revealed an association of rs2231142 with UA levels in male or obese patients, and there was no association in nonobese female patients.

CONCLUSION

The rs2231142 SNP is associated with serum UA levels and hyperuricemia in Taiwanese patients and it occurs predominantly in male or obese patients. Hyperuricemia might be controlled differently by sex and obesity.

Effects of obesity on the association between common variations in the TBX5 gene and matrix metalloproteinase 9 levels in Taiwanese

Objectives:

The TBX5 gene, a member of the T-box family, is associated with congenital heart disease, electrocardiographic parameters, and development of atrial fibrillation in the general population. This study aimed to elucidate the role of TBX5 gene polymorphisms in metabolic and inflammatory profiles possibly linked to TBX5-related pathologies.

Materials and Methods:

A sample population of 597 individuals having routine health examinations was enrolled. Five tagging TBX5 single nucleotide polymorphisms (SNPs) were analyzed using polymerase chain reaction and restriction enzyme digestion or TaqMan SNP genotyping assays. Associations between genotypes/haplotypes and matrix metalloproteinase 9 (MMP9) levels were investigated using generalized linear model analysis. Interactions between each genotype/haplotype, MMP9 level, and obesity status were tested using two-way analysis of variance with Golden Helix SVS Win32 7.3.1 software.

Results:

After adjusting for clinical covariates, TBX5 genotypes were found to be associated with MMP9 levels (p = 0.002 and p = 0.001 for rs4113925 and rs3825214, respectively) in a dominant inheritance model. Haplotype analysis using three tag SNPs (rs11067101, rs1247973, and rs3825214) revealed a significant association between TBX5 haplotype GCG and MMP9 levels (uncorrected p = 0.0093 and the corrected false discovery rate p = 0.0435). Multivariate analysis identified that SNP rs3825214, in addition to the MMP9 and E-selectin genotypes, was independently associated with MMP9 levels (p < 0.001). Using a dominant inheritance model, subgroup and interaction analysis showed associations between the rs4113925, rs3825214, and MMP9 levels only in nonobese individuals (p = 1.04 × 10⁻⁴ and p = 7.11 × 10⁻⁵, respectively; interaction p = 0.009 and 0.018, respectively). Subgroup analysis showed a borderline significant association between haplotype GCG and MMP9 levels (uncorrected p = 0.020 and corrected false discovery rate p = 0.073), but with no evidence of interaction.

Conclusion:

TBX5 genotypes/haplotypes are independently associated with MMP9 in Taiwanese individuals and occur predominantly in nonobese people. These associations may broaden our understanding of the mechanism underlying T-box family gene activity and related cardiovascular pathologies.

Association of CDH13 genotypes/haplotypes with circulating adiponectin levels, metabolic syndrome, and related metabolic phenotypes: the role of the suppression effect

Objective

Previous genome-wide association studies have indicated an association between CDH13 genotypes and adiponectin levels. In this study, we used mediation analysis to assess the statistical association between CDH13 locus variants and adiponectin levels, metabolic syndrome, and related metabolic phenotypes.

Methods and results

A sample population of 530 Taiwanese participants was enrolled. Four CDH13 gene variants in the promoter and intron 1 regions were genotyped. After adjustment for clinical covariates, the CDH13 genotypes/haplotypes exhibited an association with the adiponectin levels (lowest P = 1.95 × 10⁻¹¹ for rs4783244 and lowest P = 3.78 × 10⁻¹³ for haplotype ATTT). Significant correlations were observed between the adiponectin levels and the various metabolic syndrome-related phenotypes (all P ≤ 0.005). After further adjustment for the adiponectin levels, participants with a minor allele of rs12051272 revealed a considerable association with a more favorable metabolic profile, including higher insulin sensitivity, high-density lipoprotein cholesterol levels, lower diastolic blood pressure, circulating levels of fasting plasma glucose, and triglycerides, and as a lower risk of metabolic syndrome (all P < 0.05). The mediation analysis further revealed a suppression effect of the adiponectin levels on the association between CDH13 genotypes and metabolic syndrome and its related phenotypes (Sobel test; all P < 0.001).

Conclusion

The genetic polymorphisms at the CDH13 locus independently affect the adiponectin levels, whereas the adiponectin levels exhibit a suppressive effect on the association between CDH13 locus variants and various metabolic phenotypes and metabolic syndrome. In addition, these results provide further evidence of the association between the CDH13 gene variants and the risks of metabolic syndrome and atherosclerotic cardiovascular disease.

Treatment for diabetic foot ulcers complicated by major cardiac events

OBJECTIVE

Diabetic foot ulcer (DFU) is a major complication in patients with diabetes mellitus and the leading cause of non-traumatic amputation in adults. Patients with DFU are usually fragile due to chronic diabetic comorbidities; therefore, tedious debridement and intervention procedures may not be well tolerated in patients with DFU. This study aimed to identify a casual relationship between in-hospital complications and treatment for limb-threatening DFUs.

METHODS

From 2009 to 2011, 1130 consecutive patients who were admitted to the Diabetic Foot Care Center in Chang Gung Medical Center were surveyed. Rates of in-hospital mortality or events that lead to transfer to the intensive care unit (ICU) for various severe complications were retrospectively analyzed.

RESULTS

Forty-seven patients (4.2%) experienced in-hospital complications (28 patients died). Major adverse cardiac events (MACE) (n=21, 44.7%) were the most common complications, followed by nosocomial infection (n=18, 38.3%). Previous myocardial infarction was a risk factor for MACE. The presentation of MACE was fulminant (eg, acute pulmonary edema, cardiogenic shock,cardiac arrest), and occurred within 10 days of admission or within 10 days following a major procedure in most cases. ST-T segment abnormality at rest was the most common presentation of electrocardiography for MACE.

CONCLUSION

MACE should be prevented during treatment for limb-threatening DFU in high-risk patients. Acute stress might have caused MACE during the first 10 days after admission or a major procedure.

The (CCTTT) n pentanucleotide repeat polymorphism in the inducible nitric oxide synthase gene promoter and the risk of psoriasis in Taiwanese

Recently, genome-wide association studies identified a novel psoriasis susceptibility locus tagged by two single-nucleotide polymorphisms (SNPs) rs4795067 and rs28998802, both of which are in the intronic region of inducible nitric oxide synthase (iNOS) gene. This study aimed to assess the role of (CCTTT) n pentanucleotide repeat polymorphisms in the promoter region of iNOS gene in Chinese-Taiwanese patients with psoriasis. In total, 280 patients with psoriasis and 512 control subjects were analyzed for the presence of the iNOS microsatellite polymorphism by polymerase chain reactions. The alleles were classified as S and L alleles according to the number of (CCTTT) n repeats, with the alleles with ≤13 repeats designated as S and alleles with ≥14 repeats designated as L alleles. The distribution of allele frequencies and genotypes was significantly different between the control and psoriasis groups (P = 0.040, and 0.014, respectively). After adjustment for age, sex, body mass index, smoking, diabetes, and hypertension, carriers of the LL genotype were 0.38 (95% confidence interval 0.16-0.95) times less likely than non-carriers to have psoriasis (P = 0.038). The promoter assays demonstrated that the iNOS promoter activity increases in parallel with the repeat number of (CCTTT) n in HaCaT cells. Approximately 70% of the study subjects were genotyped for rs4795067 and rs28998802. The rs4795067 is in linkage disequilibrium with the microsatellite L/S allelic classification. The association of iNOS microsatellite with psoriasis is independent of these known iNOS variants. Our results suggest that the iNOS microsatellite may contribute to the genetic background of psoriasis in Chinese-Taiwanese patients.

Microsatellite polymorphism in the heme oxygenase-1 gene promoter and the risk of atrial fibrillation in Taiwanese

Background

Atrial fibrillation (AF) is associated with increased oxidative stress. Emerging evidence suggests that heme oxygenase-1 (HO-1) is a potent antioxidant system against various oxidative stress-related diseases. The human HO-1 promoter has a GT-repeat length polymorphism that can determine the level of gene transcription.

Objective

The aim of this study is to assess the role of the GT-repeat polymorphism in the promoter region of the HO-1 gene in Chinese-Taiwanese patients with AF.

Methods and Results

This study enrolled 200 AF patients and 240 controls, comparable for age and gender. In each subject, the length of GT-repeat polymorphism in the HO-1 promoter region was examined by polymerase chain reactions. The frequencies of long GT-repeat alleles (≧32) were significantly higher in AF patients than in controls. Multivariate analysis showed that the presence of long allele was significantly and independently associated with AF (odds ratio: 1.91, 95% CI 1.07–3.72; P = 0.028). Right atrial tissues from patients with chronic AF were investigated with immunoconfocal microscopy. Patients homozygous for shorter GT-repeat alleles exhibited greater HO-1 expression in their atria than those homozygous for longer alleles, which was reflected by less oxidative stress, myofibril degradation, and fibrosis in the atria of patients with shorter GT-repeat. In vitro, transient transfection assay in HL-1 atrial myocytes showed that the responsiveness of HO-1 transcriptional activity to tachypacing was inversely correlated with the length of the GT-repeats.

Conclusion

Our results suggest that the HO-1 microsatellite polymorphism may contribute to the genetic background of AF in Chinese-Taiwanese patients.

Improvement of Right Ventricular Function in Pulmonary Arterial Hypertension with Disease-Specific Therapy - A Clinical Observational Study

BACKGROUND

Pulmonary arterial hypertension (PAH) is a serious and progressive disorder that can result in right ventricular (RV) dysfunction and mortality. Consequently, it is important to monitor RV function during management of PAH. The aim of this study was to investigate the change in RV function by echocardiography before and after disease-specific therapy.

METHODS

We recruited 31 PAH patients with functional class (FC) III or IV. All the patients received a comprehensive assessment before disease-specific therapy was administered, including observation of clinical symptoms, 6-min walk distance (6MWD), serum brain natriuretic peptide (BNP) level, and transthoracic echocardiography. The assessment was repeated 12 weeks after therapy.

RESULTS

Twenty-eight patients with a mean age of 40 years completed the study, of whom 82% were women. We found that the etiologies were mainly connective tissue disease-associated and idiopathic PAH. Of the patients in our study, 36% received endothelin receptor antagonist and 64% received phosphodiesterase-5 inhibitor. There was a significant improvement in FC after disease-specific therapy (p < 0.001). The 6MWD increased from 326 to 403 m (p < 0.001), and the serum BNP level decreased from 242 to 130 pg/mL (p = 0.008) after treatment. Echocardiography showed significant reduction in the right atrial and RV areas, pulmonary artery pressure, RV free wall thickness, and inferior vena cava diameter. The myocardial performance index and left ventricular eccentricity index were significantly reduced after therapy.

CONCLUSIONS

For PAH patients in our study, disease-specific therapy for 12 weeks resulted in an improvement in FC, 6MWD, serum BNP levels, and RV function.

KEY WORDS

Disease-specific therapy; Pulmonary arterial hypertension; Right ventricular function.

Comparison between Exclusive and Selective Drug-Eluting Stent Strategies in Treating Patients with Multivessel Coronary Artery Disease

BACKGROUND

The expanded usage of drug-eluting stents (DES) in treating patients with multivessel coronary artery disease (CAD) may sometimes be limited in real-world practice due to cost concerns. We compared the clinical outcomes of exclusive and selective DES use in treating patients with multivessel CAD.

METHODS

From November 2004 to December 2011, 110 patients with multivessel CAD who received four or more stents were enrolled into this study, and divided into two groups according to the DES strategy employed: exclusive DES (n = 52), or selective DES (n = 58). In the selective DES group, DES was reserved for complex lesions only, such that the incidence and predictors of clinical events were assessed.

RESULTS

At a mean follow-up of 41.4 ± 26.5 months, there were no significant differences between the two strategies in terms of baseline characteristics, all-cause mortality (exclusive vs. selective: 1.9% vs. 6.9%, p = 0.21), cardiac death (1.9% vs. 1.7%, p = 0.94) and nonfatal myocardial infarction (3.8% vs. 5.2%, p = 0.74). Despite the presence of more ostial lesions in the exclusive DES group, there was a trend such that major adverse cardiac events (MACE) and target lesion revascularization (TLR) rates were higher in the selective DES group (MACE: 17.3% vs. 31%, p = 0.16; TLR: 11.5% vs. 24.1%, p = 0.08). The higher MACE rate in the selective DES group was mainly driven by a higher target vessel revascularization (TVR) rate (15.4% vs. 29.3%, p = 0.08). In the exclusive DES group, SYNTAX score was an independent predictor of MACE [Haxard ratio (HR): 1.09, 95% confidence internal (CI): 1.02-1.16, p = 0.01] and TVR (HR 1.08, 95% CI 1.01-1.15, p = 0.04).

CONCLUSIONS

Compared to the exclusive DES strategy, the selective DES strategy with reservation of DES for complex lesions is associated with numerically higher, but not statistically significant, rates of MACE and all-cause mortality in this small group of patients with multivessel CAD receiving four or more stents.

KEY WORDS

Bare metal stent; Drug-eluting stent; Multivessel coronary artery disease.

Leptin-to-Adiponectin Ratio is Related to Low Grade Inflammation and Insulin Resistance Independent of Obesity in Non-Diabetic Taiwanese: A Cross-Sectional Cohort Study

BACKGROUND

Leptin and adiponectin are secreted from adipose tissue and exert opposing effects on C-reactive protein (CRP) levels and insulin resistance. As hypertrophic adipocytes secrete more leptin and less adiponectin, the leptin-to adiponectin ratio (LAR) has been proposed as a useful measure of insulin resistance and vascular risk. We investigated whether LAR may serve as a better predictor than either leptin or adiponectin alone for low-grade inflammation and insulin resistance independent of obesity in a non-diabetic Taiwanese population.

METHODS

This study included 568 non-diabetic Taiwanese individuals (297 men, 271 women). CRP, leptin and adiponectin were measured using enzyme-linked immunosorbent assay. The degree of insulin resistance was determined using the homeostasis model assessment of insulin resistance (HOMA-IR).

RESULTS

In the receiver operator characteristic analysis, the area under the curve of LAR in predicting individuals with elevated CRP and insulin resistance was significantly greater than that for either leptin (p = 0.0035 vs. elevated CRP, p < 0.0001 vs. insulin resistance) or adiponectin alone (p = 0.0131 vs. elevated CRP, p = 0.0006 vs. insulin resistance), suggesting that LAR might be a better predictor of individuals with low grade inflammation and insulin resistance. In the multivariable analysis adjusted for age, gender, smoking status, and components of metabolic syndrome, LAR was still strongly associated with levels of CRP (p < 0.001, all participants; p = 0.002, nonobese individuals; p < 0.001, obese individuals) and HOMA-IR index (p < 0.001, all participants, obese and nonobese individuals).

CONCLUSIONS

The LAR is related to low grade inflammation and insulin resistance independent of obesity in non-diabetic Taiwanese, and the strength of associations between LAR with CRP and HOMA-IR are greater than the association with leptin or adiponectin alone.

KEY WORDS

Adiponectin; C-reactive protein; Insulin resistance; Leptin; Obesity.

Whole-exome sequencing to identify a novel LMNA gene mutation associated with inherited cardiac conduction disease

Background

Inherited cardiac conduction diseases (CCD) are rare but are caused by mutations in a myriad of genes. Recently, whole-exome sequencing has successfully led to the identification of causal mutations for rare monogenic Mendelian diseases.

Objective

To investigate the genetic background of a family affected by inherited CCD.

Methods and Results

We used whole-exome sequencing to study a Chinese family with multiple family members affected by CCD. Using the pedigree information, we proposed a heterozygous missense mutation (c.G695T, Gly232Val) in the lamin A/C (LMNA) gene as a candidate mutation for susceptibility to CCD in this family. The mutation is novel and is expected to affect the conformation of the coiled-coil rod domain of LMNA according to a structural model prediction. Its pathogenicity in lamina instability was further verified by expressing the mutation in a cellular model.

Conclusions

Our results suggest that whole-exome sequencing is a feasible approach to identifying the candidate genes underlying inherited conduction diseases.

Prognostic value of global left ventricular strain for conservatively treated patients with symptomatic aortic stenosis

AIMS

Impaired left ventricular (LV) strain is associated with an increased risk of cardiac events in asymptomatic severe aortic stenosis (AS). We aimed to evaluate the prognostic value of global LV strain in conservatively treated patients with symptomatic AS.

METHODS AND RESULTS

This cohort study retrospectively reviewed symptomatic AS patients who were treated conservatively or surgically between July 2007 and April 2010. We measured their global longitudinal strain (GLS) and global circumferential strain (GCS). Clinical events were defined as readmission for heart failure or all-cause death for 2 years. GLS and GCS could predict a worse outcome in the conservatively treated group at cut-offs of =-16.5% (77% sensitivity and 67% specificity) and =-22.2% (92% sensitivity and 83% specificity), respectively. By univariate Cox regression analysis, age, logistic EuroSCORE, aortic valve area, GLS, and GCS were significant predictors. When adjusted for age, logistic EuroSCORE, and aortic valve area, impaired GLS and GCS were independently associated with a higher risk of clinical events.

CONCLUSION

In conservatively treated patients with symptomatic AS, impaired GLS and GCS were associated with an increased risk of cardiac events during a 2-year follow-up. Global LV strain may help to define a higher risk subset; therefore, a larger and prospective observation study would be necessary.