👤 Hanbin Jang

The concentration of high-density lipoprotein-cholesterol (HDL-C) in humans is partially determined by genetic factors; however, the role of these factors is incompletely understood. The aim of this study was to examine the prevalence and characteristics of CETP, LIPC, and SCARB1 variants in Korean individuals with extremely high HDL-C levels. We also analysed associations between these variants and cholesterol efflux capacity (CEC), reactive oxygen species (ROS) generation, and vascular cell adhesion molecule-1 (VCAM-1) expression. Of 13,545 participants in the cardiovascular genome cohort, 42 subjects with HDL-C levels >100 mg/dL were analysed. The three target genes were sequenced by targeted next-generation sequencing, the functional effects of detected variants were predicted, and CEC was assessed using a radioisotope and apolipoprotein B-depleted sera. We observed two rare variants of CETP in 13 individuals (rare variant c.A1196G [p.D399G] of CETP was discovered in 12 subjects) and one rare variant of SCARB1 in one individual. Furthermore, all subjects had at least one of four common variants (one CETP and three LIPC variants). Two additional novel CETP variants of unknown frequency were found in two subjects. However, the identified variants did not show significant associations with CEC, ROS generation, or VCAM-1 expression. Our study provides additional insights into the role of genetics in individuals with extremely high HDL-C. Show less

To evaluate cardiovascular (CV) outcomes in outpatients with coronary artery disease (CAD) living alone compared with those living with others. The prospeCtive observational LongitudinAl RegIstry oF patients with stable coronarY artery disease (CLARIFY) included outpatients with stable CAD. CLARIFY enrolled participants in 45 countries from November 2009 to July 2010, with 5 years of follow-up. Living arrangement was documented at baseline. The primary outcome was a composite of major adverse cardiovascular events (MACEs) defined as CV death, myocardial infarction (MI) and stroke. Among 32 367 patients, 3648 patients were living alone (11.3%). After multivariate adjustment, there were no residual differences in MACE among patients living alone compared with those living with others (HR 1.04, 95% CI 0.92 to 1.18, p=0.52); however, there was significant heterogeneity in the exposure effect by sex (P Living alone was not associated with an independent increase in MACE, although significant sex-based differences were apparent. Men living alone may have a worse prognosis from CV disease than women; further analyses are needed to elucidate the mechanisms underlying this difference. ISRCTN43070564. Show less

Multiple osteochondromas (MOs) or hereditary multiple exostoses is a rare autosomal-dominant disease characterized by growths of MOs, which are benign cartilage-capped bone tumors that grow away from the growth plates. Almost 90% of MOs have a molecular explanation and 10% are unexplained. MOs are genetically heterogeneous with two causal genes on 8q24.11 (EXT1) and 11p12 (EXT2), with a higher frequency in EXT1. MO is a very rare genetic disorder, and the genotype-phenotype of MO with EXT2 mutation has not been well investigated in Korea. We present the clinical radiographic and molecular analysis of a four-generation Korean family with 11 MO-affected members (seven males and four females). The affected members from the third generation available for molecular analysis and their detailed medical histories showed moderate-to-severe phenotypes (clinical classes II-III), including bony deformities and limb misalignment with pain requiring surgical correction. The x-rays showed MOs in multiple sites. A novel EXT2 frameshift mutation (c.590delC, p.P197Qfs*73) was revealed by targeted exome sequencing in the affected members of this family. In this article, we not only expand the phenotypic-genotypic spectrum of MOs but also highlight the phenotypic heterogeneity in a family with the same mutation. In addition, we compiled the mutation spectrum of EXT2 from a literature review and identified that exon 2 of EXT2 is a mutation hot spot. Early medical attention with diagnosis of MO through careful examination of the clinical manifestations and genetic analysis can provide the opportunity to establish coordinated multispecialty management of the patient. Show less

Gene editing nucleases, represented by CRISPR-associated protein 9 (Cas9), are becoming mainstream tools in biomedical research. Successful delivery of CRISPR/Cas9 elements into the target cells by transfection is a prerequisite for efficient gene editing. This protocol demonstrates that tube electroporation (TE) machine-mediated delivery of CRISPR/Cas9 ribonucleoprotein (RNP), along with single-stranded oligodeoxynucleotide (ssODN) donor templates to different types of mammalian cells, leads to robust precise gene editing events. First, TE was applied to deliver CRISPR/Cas9 RNP and ssODNs to induce disease-causing mutations in the interleukin 2 receptor subunit gamma (IL2RG) gene and sepiapterin reductase (SPR) gene in rabbit fibroblast cells. Precise mutation rates of 3.57%-20% were achieved as determined by bacterial TA cloning sequencing. The same strategy was then used in human iPSCs on several clinically relevant genes including epidermal growth factor receptor (EGFR), myosin binding protein C, cardiac (Mybpc3), and hemoglobin subunit beta (HBB). Consistently, highly precise mutation rates were achieved (11.65%-37.92%) as determined by deep sequencing (DeepSeq). The present work demonstrates that tube electroporation of CRISPR/Cas9 RNP represents an efficient transfection protocol for gene editing in mammalian cells. Show less

We investigated the prevalence and characteristics of variants of five lipolysis-related genes in Korean patients with very high triglycerides (TGs). Twenty-six patients with TG levels >885 mg/dL were selected from 13545 Korean subjects. Five candidate genes, LPL, APOC2, GPIHBP1, APOA5, and LMF1, were sequenced by targeted next-generation sequencing. Predictions of functional effects were performed and matched against public databases of variants. Ten rare variants of three genes were found in nine (34.6%) patients (three in LPL, four in APOA5, and three in LMF1). Five were novel and all variants were suspected of being disease-causing. Nine were heterozygous, and one (3.8%) had a homozygous rare variant of LPL. Six common variants of four genes were observed in 25 (96.2%) patients (one in LPL, one in GPIHBP1, two in APOA5, and two in LMF1). The c.G41T variant of GPIHBP1 and c.G533T variant of APOA5 were most frequent and found in 15 (57.7%) and 14 (53.8%) patients, respectively. Rare homozygous variants of the genes were very uncommon, while diverse rare heterozygous variants were commonly identified. Taken together, most study subjects may be manifesting the combined effects of rare heterozygous variants and common variants. Show less

Oxidative stress activates macroautophagy/autophagy and contributes to atherogenesis via lipophagic flux, a form of lipid removal by autophagy. However, it is not known exactly how endogenous antioxidant enzymes are involved in lipophagic flux. Here, we demonstrate that the antioxidant PRDX1 (peroxiredoxin 1) has a crucial role in the maintenance of lipophagic flux in macrophages. PRDX1 is more highly expressed than other antioxidant enzymes in monocytes and macrophages. We determined that Prdx1 deficiency induced excessive oxidative stress and impaired maintenance of autophagic flux in macrophages. Prdx1-deficient macrophages had higher intracellular cholesterol mass and lower cholesterol efflux compared with wild type. This perturbation in cholesterol homeostasis was due to impaired lipophagic cholesterol hydrolysis caused by excessive oxidative stress, resulting in the inhibition of free cholesterol formation and the reduction of NR1H3 (nuclear receptor subfamily 1, group H, member 3) activity. Notably, impairment of both lipophagic flux and cholesterol efflux was restored by the 2-Cys PRDX-mimics ebselen and gliotoxin. Consistent with this observation, apoe Show less

We performed an integrated analysis of proteomic and transcriptomic datasets to develop potential diagnostic markers for early pancreatic cancer. In the discovery phase, a multiple reaction monitoring assay of 90 proteins identified by either gene expression analysis or global serum proteome profiling was established and applied to 182 clinical specimens. Nine proteins (P < 0.05) were selected for the independent validation phase and quantified using stable isotope dilution-multiple reaction monitoring-mass spectrometry in 456 specimens. Of these proteins, four proteins (apolipoprotein A-IV, apolipoprotein CIII, insulin-like growth factor binding protein 2 and tissue inhibitor of metalloproteinase 1) were significantly altered in pancreatic cancer in both the discovery and validation phase (P < 0.01). Moreover, a panel including carbohydrate antigen 19-9, apolipoprotein A-IV and tissue inhibitor of metalloproteinase 1 showed better performance for distinguishing early pancreatic cancer from pancreatitis (Area under the curve = 0.934, 86% sensitivity at fixed 90% specificity) than carbohydrate antigen 19-9 alone (71% sensitivity).Overall, we present the panel of robust biomarkers for early pancreatic cancer diagnosis through bioinformatics analysis that combined transcriptomic and proteomic data as well as rigorous validation on a large number of independent clinical samples. Show less

The present study aimed to identify potentially critical differentially methylated genes associated with the progression of nasopharyngeal carcinoma (NPC). Methylation profiling data of GSE62336 deposited in the Gene Expression Omnibus database were used to identify differentially methylated regions (DMRs) and differentially methylated CpG islands (DMIs). Concurrently, differentially expressed genes (DEGs) were identified using a meta-analysis of three gene expression datasets (GSE53819, GSE13597 and GSE12452). Subsequently, methylated DEGs were identified by comparing DMRs and DEGs. Furthermore, functional associations of these methylated DEGs were analyzed via constructing a functional network using GeneMANIA prediction server. In total, 1,676 hypermethylated genes, 28 hypomethylated genes, 17 DMIs and 2,983 DEGs (1,655 upregulated and 1,328 downregulated) were identified. Among these DEGs, 135 downregulated genes were hypermethylated; of these, dual specificity phosphatase 6 ( Show less

Genome-wide association studies have been used extensively to identify genetic variants linked to metabolic syndrome (MetS), but most of them have been conducted in non-Asian populations. This study aimed to evaluate the association between MetS and previously studied single nucleotide polymorphisms (SNPs), and their interaction with health-related behavior in Korean men. Seventeen SNPs were genotyped and their association with MetS and its components was tested in 1193 men who enrolled in the study at Seoul National University Hospital. We found that rs662799 near APOA5 and rs769450 in APOE had significant association with MetS and its components. The SNP rs662799 was associated with increased risk of MetS, elevated triglyceride (TG) and low levels of high-density lipoprotein, while rs769450 was associated with a decreased risk of TG. The SNPs showed interactions between alcohol drinking and physical activity, and TG levels in Korean men. We have identified the genetic association and environmental interaction for MetS in Korean men. These results suggest that a strategy of prevention and treatment should be tailored to personal genotype and the population. Show less

Metformin is a first-line drug for treating type 2 diabetes. Although metformin is known to phosphorylate AMP-activated protein kinase (AMPK), it is unclear how the glucose-lowering effect of metformin is related to AMPK activation. The aim of this study was to identify the urinary endogenous metabolites affected by metformin and to identify the novel underlying molecular mechanisms related to its anti-diabetic effect. Fourteen healthy male subjects were orally administered metformin (1000 mg) once. First morning urine samples were taken before and after administration to obtain metabolomic data. We then further investigated the anti-diabetic mechanism of metformin in vitro and in vivo. The fluctuation of the metabolite cortisol indicated that the neuroendocrine system was involved in the anti-diabetic effect of metformin. Actually we found that metformin induced AMPK/liver X receptor α (LXRα) phosphorylation, followed by pro-opiomelanocortin (POMC) suppression in rat pituitary cells. We confirmed this result by administering metformin in an animal study. Given that cortisol stimulates gluconeogenesis, we propose the anti-hyperglycemic effect of metformin is attributed to reduced POMC/adrenocorticotropic hormone (ACTH)/cortisol levels following AMPK/LXRα phosphorylation in the pituitaries. Show less

Honokiol and magnolol, as pharmacological biphenolic compounds of Magnolia officinalis, have been reported to have antioxidant and anti-inflammatory properties. Sterol regulatory element binding protein-1 c (SREBP-1 c) plays an important role in the development and processing of steatosis in the liver. In the present study, we investigated the effects of a combination of honokiol and magnolol on SREBP-1 c-dependent lipogenesis in hepatocytes as well as in mice with fatty liver due to consumption of high-fat diet (HFD). Liver X receptor α (LXRα) agonists induced activation of SREBP-1 c and expression of lipogenic genes, which were blocked by co-treatment of honokiol and magnolol (HM). Moreover, a combination of HM potently increased mRNA of fatty acid oxidation genes. HM induced AMP-activated protein kinase (AMPK), an inhibitory kinase of the LXRα-SREBP-1 c pathway. The role of AMPK activation induced by HM was confirmed using an inhibitor of AMPK, Compound C, which reversed the ability of HM to both inhibit SREBP-1 c induction as well as induce genes for fatty acid oxidation. In mice, HM administration for four weeks ameliorated HFD-induced hepatic steatosis and liver dysfunction, as indicated by plasma parameters and Oil Red O staining. Taken together, our results demonstrated that a combination of HM has beneficial effects on inhibition of fatty liver and SREBP-1 c-mediated hepatic lipogenesis, and these events may be mediated by AMPK activation. Show less

Hepatic resection is the most curative treatment option for early-stage hepatocellular carcinoma, but is associated with a high recurrence rate, which exceeds 50% at 5 years after surgery. Understanding the genetic basis of hepatocellular carcinoma at surgically curable stages may enable the identification of new molecular biomarkers that accurately identify patients in need of additional early therapeutic interventions. Whole exome sequencing and copy number analysis was performed on 231 hepatocellular carcinomas (72% with hepatitis B viral infection) that were classified as early-stage hepatocellular carcinomas, candidates for surgical resection. Recurrent mutations were validated by Sanger sequencing. Unsupervised genomic analyses identified an association between specific genetic aberrations and postoperative clinical outcomes. Recurrent somatic mutations were identified in nine genes, including TP53, CTNNB1, AXIN1, RPS6KA3, and RB1. Recurrent homozygous deletions in FAM123A, RB1, and CDKN2A, and high-copy amplifications in MYC, RSPO2, CCND1, and FGF19 were detected. Pathway analyses of these genes revealed aberrations in the p53, Wnt, PIK3/Ras, cell cycle, and chromatin remodeling pathways. RB1 mutations were significantly associated with cancer-specific and recurrence-free survival after resection (multivariate P = 0.038 and P = 0.012, respectively). FGF19 amplifications, known to activate Wnt signaling, were mutually exclusive with CTNNB1 and AXIN1 mutations, and significantly associated with cirrhosis (P = 0.017). RB1 mutations can be used as a prognostic molecular biomarker for resectable hepatocellular carcinoma. Further study is required to investigate the potential role of FGF19 amplification in driving hepatocarcinogenesis in patients with liver cirrhosis and to investigate the potential of anti-FGF19 treatment in these patients. Show less

Heterochromatin protein 1 (HP1) proteins are chromatin-bound transcriptional regulators. While their chromodomain binds histone H3 methylated on lysine 9, their chromoshadow domain associates with the H3 histone fold in a region involved in chromatin remodeling. Here, we show that phosphorylation at histone H3 threonine 45 and serine 57 within this latter region differentially affects binding of the three mammalian HP1 isoforms HP1α, HP1β and HP1γ. Both phosphorylation events are dependent on the activity of the DYRK1A kinase that antagonizes HP1-mediated transcriptional repression and participates in abnormal activation of cytokine genes in Down's syndrome-associated megakaryoblastic leukemia. Show less

Several serum markers are used to assess hepatocyte damage, but they have limitations related to etiology specificity and prognostication. Identification of novel hepatocyte-specific biomarkers could provide important prognostic information and better pathogenesis classification. We tested the hypothesis that hepatocyte-selective biomarkers are released after subjecting isolated mouse hepatocytes to Fas-ligand-mediated apoptosis. Proteomic analysis of hepatocyte culture medium identified the mitochondrial matrix protein carbamoyl phosphate synthetase-1 (CPS1) among the most readily detected proteins that are released by apoptotic hepatocytes. CPS1 was also detected in mouse serum upon acute challenge with Fas-ligand or acetaminophen and in hepatocytes upon hypoosmotic stress, independent of hepatocyte caspase activation. Furthermore, CPS1 was observed in sera of mice chronically fed the hepatotoxin 3,5-diethoxycarbonyl-1,4-dihydrocollidine. Mouse CPS1 detectability was similar in serum and plasma, and its half-life was 126 ± 9 min. Immune staining showed that CPS1 localized to mouse hepatocytes but not ductal cells. Analysis of a few serum samples from patients with acute liver failure (ALF) due to acetaminophen, Wilson disease, or ischemia showed readily detectable CPS1 that was not observed in several patients with chronic viral hepatitis or in control donors. Notably, CPS1 rapidly decreased to undetectable levels in sera of patients with acetaminophen-related ALF who ultimately recovered, while alanine aminotransferase levels remained elevated. Therefore, CPS1 becomes readily detectable upon hepatocyte apoptotic and necrotic death in culture or in vivo. Its abundance and short serum half-life, compared with alanine aminotransferase, suggest that it may be a useful prognostic biomarker in human and mouse liver injury. Show less

Liver X receptor (LXR) is an oxysterol-activated nuclear receptor involved in the control of major metabolic pathways for cholesterol homeostasis and lipogenesis. Although the role of LXR in hepatic steatosis is well known, its correlation with intrahepatic inflammation and fibrosis has not been thoroughly studied. We investigated the association between LXRα, hepatic inflammation, and fibrosis, as well as its correlation with other intrahepatic lipid transporters in patients with nonalcoholic fatty liver disease (NAFLD). We evaluated clinical characteristics including sex, age, body mass index, and laboratory findings from 40 NAFLD and 16 control patients. Immunohistochemical staining was carried out on liver biopsy samples from all patients. The positive rate of LXRα expression was 30 % in the control group, 50 % in the NAFLD group, and 97 % in NASH groups. LXRα expression was positively correlated with not only the amount of intrahepatic fat, but also with intrahepatic inflammation and hepatic fibrosis. LXRα expression showed positive correlation with intrahepatic expression of ABCG5/8, CD36, and SREBP-1c. The expression of ABCA1, ABCG5/8, SREBP-1c, and CD36 was higher in NAFLD than in controls and there was no further increase in the NASH group. NPC1L1 was abundant in human liver. Expression of NPC1L1 was negatively correlated with intrahepatic inflammation and LXRα intensity. LXR expression correlated with the degree of hepatic fat deposition, as well as with hepatic inflammation and fibrosis in NAFLD patients. Our research suggests that LXR is an attractive target for treatment and regulation of hepatic inflammation and fibrosis. Show less

Statins are suggested to preserve gallbladder function by suppressing pro-inflammatory cytokines and preventing cholesterol accumulation in gallbladder epithelial cells. They also affect cross-talk among the nuclear hormone receptors that regulate cholesterol-bile acid metabolism in the nuclei of hepatocytes. However, there is controversy over whether or how statins change the expression of peroxisome proliferator-activated receptor (PPAR)alpha, PPARgamma, liver X receptor alpha (LXRalpha), farnesoid X receptor (FXR), ABCG5, ABCG8, and 7alpha-hydroxylase (CYP7A1) which are directly involved in the cholesterol saturation index in bile. Human Hep3B cells were cultured on dishes. MTT assays were performed to determine the appropriate concentrations of reagents to be used. The protein expression of PPARalpha and PPARgamma was measured by Western blotting analysis, and the mRNA expression of LXRalpha, FXR, ABCG5, ABCG8 and CYP7A1 was estimated by RT-PCR. In cultured Hep3B cells, pravastatin activated PPARalpha and PPARgamma protein expression, induced stronger expression of PPARgamma than that of PPARalpha, increased LXRalpha mRNA expression, activated ABCG5 and ABCG8 mRNA expression mediated by FXR as well as LXRalpha, enhanced FXR mRNA expression, and increased CYP7A1 mRNA expression mediated by the PPARgamma and LXRalpha pathways, together or independently. Our data suggested that pravastatin prevents cholesterol gallstone diseases via the increase of FXR, LXRalpha and CYP7A1 in human hepatocytes. Show less

Screening of matrix metalloproteinase (MMP)-14 substrates in human plasma using a proteomics approach previously identified apolipoprotein A-IV (apoA-IV) as a novel substrate for MMP-14. Here, we show that among the tested MMPs, purified apoA-IV is most susceptible to cleavage by MMP-7, and that apoA-IV in plasma can be cleaved more efficiently by MMP-7 than MMP-14. Purified recombinant apoA-IV (44-kDa) was cleaved by MMP-7 into several fragments of 41, 32, 29, 27, 24, 22 and 19 kDa. N-terminal sequencing of the fragments identified two internal cleavage sites for MMP-7 in the apoA-IV sequence, between Glu(185) and Leu(186), and between Glu(262) and Leu(263). The cleavage of lipid-bound apoA-IV by MMP-7 was less efficient than that of lipid-free apoA-IV. Further, MMP-7-mediated cleavage of apoA-IV resulted in a rapid loss of its intrinsic anti-oxidant activity. Based on the fact that apoA-IV plays important roles in lipid metabolism and possesses anti-oxidant activity, we suggest that cleavage of lipid-free apoA-IV by MMP-7 has pathological implications in the development of hyperlipidemia and atherosclerosis. Show less

We previously showed that the -1131T→C polymorphism (rs662799) of the apolipoprotein A-V gene (APOA5) and the C→T polymorphism (rs6929846) of the butyrophilin, subfamily 2, member A1 gene (BTN2A1) were significantly associated with an increased serum concentration of triglycerides, a decreased serum concentration of high density lipoprotein (HDL)-cholesterol, and the prevalence of metabolic syndrome (MetS) in Japanese individuals. The purpose of the present study was to examine whether these polymorphisms synergistically affect the prevalence of dyslipidemia and MetS in East Asian populations. The study populations comprised 7471 Japanese and 3529 Korean individuals in the dyslipidemia study, and 3474 Japanese and 1671 Korean individuals in the MetS study. Multivariable logistic regression analysis of combined genotypes with adjustment for age, gender and diabetes mellitus revealed that rs662799 and rs6929846 significantly and synergistically affected dyslipidemia. Japanese or Korean individuals with the C allele of APOA5 and the T allele of BTN2A1 had a 2.05- or 1.92-fold increased risk for hypertriglyceridemia and a 1.82- or 1.56-fold increased risk for hypo-HDL-cholesterolemia, respectively, compared to those with the TT genotype of APOA5 and the CC genotype of BTN2A1. Similar analysis with adjustment for age and gender revealed that Japanese individuals, but not Korean individuals, with the C allele of APOA5 and the T allele of BTN2A1 had a 2.87-fold increased risk for MetS compared to those with the TT genotype of APOA5 and the CC genotype of BTN2A1. Genetic variants of APOA5 and BTN2A1 may synergistically affect the prevalence of dyslipidemia in East Asian populations and of MetS in Japanese individuals. Show less

Multiplex reverse transcription polymerase chain reaction (mRT-PCR) has recently emerged as an alternative to cytogenetics. We designed and used simplified mRT-PCR system as a molecular screen for acute leukemia. Fifteen fusion transcripts were included: BCR-ABL1, PML-RARA, ZBTB16-RARA, RUNX1-RUNX1T1, CBFB-MYH11, DEK-NUP214, TCF3-PBX1, ETV6-RUNX1, MLL-AFF1, MLL-MLLT4, MLL-MLLT3, MLL-MLLT10, MLL-ELL, MLL-MLLT1, and MLL-MLLT6. A total of 121 diagnostic acute leukemia specimens were studied, comparing the mRT-PCR system with standard cytogenetics. Fifty-six cases (46.3%) had fusion transcripts revealed by our mRT-PCR assay. The concordance rate between mRT-PCR and cytogenetics was 91.7%. However, false negative results were found in three cases who have inv(16), t(4;11) or t(11;19)(q23;p13.1), respectively. Seven cryptic translocations including ETV6-RUNX1, MLL-MLLT3, MLL-MLLT4, and PML-RARA were detected. This mRT-PCR assay is a useful screening tool in acute leukemia because it provides rapid and reliable detection of clinically important chimeric transcripts. In addition, cryptic translocations provide additional genetic information that could be clinically useful. Show less

The vertebrate body plan features a consistent left-right (LR) asymmetry of internal organs. In several vertebrate embryos, motile cilia generate an asymmetric fluid flow that is necessary for normal LR development. However, the mechanisms involved in orienting LR asymmetric flow with previously established anteroposterior (AP) and dorsoventral (DV) axes remain poorly understood. In zebrafish, asymmetric flow is generated in Kupffer's vesicle (KV). The cellular architecture of KV is asymmetric along the AP axis, with more ciliated cells densely packed into the anterior region. Here, we identify a Rho kinase gene, rock2b, which is required for normal AP patterning of KV and subsequent LR development in the embryo. Antisense depletion of rock2b in the whole embryo or specifically in the KV cell lineage perturbed asymmetric gene expression in lateral plate mesoderm and disrupted organ LR asymmetries. Analyses of KV architecture demonstrated that rock2b knockdown altered the AP placement of ciliated cells without affecting cilia number or length. In control embryos, leftward flow across the anterior pole of KV was stronger than rightward flow at the posterior end, correlating with the normal AP asymmetric distribution of ciliated cells. By contrast, rock2b knockdown embryos with AP patterning defects in KV exhibited randomized flow direction and equal flow velocities in the anterior and posterior regions. Live imaging of Tg(dusp6:memGFP)(pt19) transgenic embryos that express GFP in KV cells revealed that rock2b regulates KV cell morphology. Our results suggest a link between AP patterning of the ciliated Kupffer's vesicle and LR patterning of the zebrafish embryo. Show less

We investigated the association of polymorphisms in FADS genes with polyunsaturated fatty acids (PUFAs) in serum phospholipids, lipid peroxides, and coronary artery disease (CAD) in Koreans. In this case-control study, CAD patients (n=756, 40-79 years) and healthy controls (n=890) were genotyped for rs174537 near FADS1 (FEN1 rs174537G>T), FADS2 (rs174575, rs2727270), and FADS3 (rs1000778). We calculated the odds ratios (ORs) for CAD risk and measured serum PUFA composition and lipid peroxide. Among four SNPs, only rs174537G>T differed in allele frequencies between controls and CAD patients after adjustment for age, BMI, cigarette smoking, alcohol consumption, hypertension, diabetes mellitus, and hyperlipidemia (P=0.017). The minor T allele was associated with a lower risk of CAD [OR 0.75 (95%CI 0.61-0.92), P=0.006] after adjustment. rs174537T carriers had a significantly higher proportion of linoleic acid (LA, 18:2ω6), lower arachidonic acid (AA, 20:4ω6), and lower ratios of AA/dihomo-γ-linolenic acid (DGLA, 20:3ω6) and AA/LA than G/G subjects in both control and CAD groups. In the control group, 174537T carriers had significantly lower levels of total- and LDL-cholesterol, malondialdehyde, and ox-LDL. In CAD patients, rs174537T carriers showed a larger LDL particle size than G/G subjects. The proportion of AA in serum phospholipids positively correlated with LDL-cholesterol, ox-LDL, and malondialdehyde in controls and with 8-epi-prostaglandin F(2α) in both control and CAD groups. The rs174537T is associated with a lower proportion of AA in serum phospholipids and reduced CAD risk, in association with reduced total- and LDL-cholesterol and lipid peroxides. Show less

We determined the contribution of the combination of FEN1 10154G>T with the most significant association in the analysis of plasma arachidonic acid (AA, 20:4ω6) and the APOA5-1131T>C on phospholipid ω6PUFA and coronary artery disease (CAD). Patients with CAD (n = 807, 27-81 years of age) and healthy controls (n = 1123) were genotyped for FEN1 10154G>T and APOA5-1131T>C. We found a significant interaction between these two genes for CAD risk (P = 0.007) adjusted for confounding factors. APOA5-1131C allele carriers had a higher CAD risk [odds ratio (OR):1.484, 95% confidence interval (CI):1.31-1.96; P = 0.005] compared with APOA5-1131TT individuals in the FEN1 10154GG genotype group but not in the FEN1 10154T allele group (OR:1.096, 95%CI:0.84-1.43; P = 0.504). Significant interactions between these two genes were also observed for the AA proportion (P = 0.04) and the ratio of AA/linoleic acid (LA, 18:2ω6) (P = 0.004) in serum phospholipids of controls. The APOA5-1131C allele was associated with lower AA (P = 0.027) and AA/LA (P = 0.014) only in controls carrying the FEN1 10154T allele. In conclusion, the interaction between these genes suggests that the FEN1 10154T variant allele decreases AA and AA/LA in the serum phospholipids of carriers of the APOA5-1131C allele, but contributes no significant increase in CAD risk for this population subset despite their increased triglylcerides and decreased apoA5. Show less

We aimed to determine the influence of apolipoprotein A5 gene (APOA5)-1131T>C single nucleotide polymorphism on the effects of dietary intervention and regular exercise (DIRE) targeting ApoA5 and triglyceride (TG) concentrations. Hypertriglyceridemia patients (TG, 150-500mg/dL, n=283) undertook a 12-week DIRE (replacing 1/3 of refined rice in their diets with legumes, increasing vegetable intake, and regular walking). Pre-treatment, no genotype-related differences were detected in ApoA5, TG, or HDL cholesterol levels; however, post-treatment, subjects homozygous (T/T) for the T allele had lower serum TG (P=0.009) and higher HDL cholesterol (P=0.036) than other subjects. In T/T subjects, after adjustments for age, sex and weight changes (r1) or initial TG levels (r2), changes in ApoA5 levels negatively correlated with TG changes (r1=-0.29, P=0.05, r2=-0.28, P<0.1) and positively correlated with changes in HDL cholesterol (r1=0.30, P<0.05, r2=0.32, P<0.05) and free fatty acid (r1=0.38, P<0.01, r2=0.40, P<0.01). In those with moderate hypertriglyceridemia (TG, 200-500mg/dL, n=130), APOA5-1131T/T carriers achieved significantly lower TG (P=0.007) and higher HDL cholesterol (P<0.001) than -1131C allele carriers. Additionally, statistically significant interactions between the -1131T>C and the compliance of DIRE were found for the change in TG (P=0.002) and HDL cholesterol (P=0.039). In good compliance group, T/T subjects showed greater reduction of TG and higher increase of HDL cholesterol than other subjects. On the other hand, non-good compliance group had no significant improvement in these variables. APOA5-1131T/T carriers may benefit more from the DIRE than C allele carriers. These effects were remarkable in patients with moderate hypertriglyceridemia and the individuals with good compliance. Show less

Apolipoprotein A5 (APOA5) -1131C allele is associated with higher triglyceride, an independent cardiovascular risk factor and a commonly recognized lipid abnormality in diabetes mellitus (DM). We investigated the association of APOA5 -1131T>C or S19W with DM. Study subjects were all women and categorized into metabolically healthy controls (n = 2033) and DM subjects (n = 304). Association of APOA5 -1131T>C with DM was calculated by odds ratio (OR). Anthropometric parameters, fasting glucose, and lipid profiles were measured. C carriers, particularly those with CC homozygote, had higher triglyceride and lower high-density lipoprotein cholesterol in both healthy controls (P < .001 and P < .001) and DM patients (P = .002 and P = .006) after the adjustment for age, body mass index, menopause, smoking, and drinking. APOA5 -1131C allele was associated with an increased risk of DM (OR, 1.61 [95% confidence interval {CI}, 1.23-2.10]; P < .001) after adjustment for the above confounders. Further adjustment for fasting triglyceride or/and high-density lipoprotein cholesterol attenuated a little bit, but still significantly increased the risk of DM in C carriers (OR(2), 1.36 [95% CI, 1.02-1.80]; P = .035 and OR(3), 1.36 [95% CI, 1.032-1.79]; P = .029, respectively). Interestingly, C allele carriers in DM patients showed a positive correlation between fasting glucose and triglyceride after the adjustment (r = 0.172, P = .035). On the other hand, this significant correlation was not observed in healthy women. Regarding S19W, minor allele was not found in our study population from prescreening test. In conclusion, APOA5 -1131C allele may contribute to the increased susceptibility of DM in Korean women. In addition, positive correlation between fasting glucose and triglyceride in C carriers of DM patients suggested that C allele in hyperglycemic states may be more susceptible to the risk of cardiovascular disease. Show less

Whereas the relation between apolipoprotein A5 (APOA5) gene polymorphisms and triglycerides (TG) levels is well established, the associations between apoA5 concentrations, TG and coronary artery disease (CAD) remain controversial. Therefore, we investigated these relations in the setting of a case-control study involving Korean males. ApoA5, TG, insulin, free fatty acid (FFA) and lipoprotein profiles were determined using a cross-sectional design in 777 healthy controls and 367 CAD patients. Plasma apoA5 concentration was lower in CAD patients than controls (192.7+/-5.2 vs. 237.2+/-3.7ng/ml, P<0.001). Values in the second and top tertiles of apoA5 were associated with a decreased odds ratio (OR) for CAD when compared with values in the bottom tertile; OR for apoA5 top tertile was 0.33 (95% CI, 0.23-0.47) in the age- and BMI-adjusted model and 0.35 (95% CI, 0.23-0.56) following additional adjustments for smoking, drinking status, blood pressure, TG and HDL-cholesterol. After adjustment for age and BMI, plasma apoA5 concentration was negatively correlated with serum TG (r=-0.188, P<0.001) and insulin (r=-0.185, P<0.001) in normotriglyceridemic controls (TG<150mg/dL, n=509) whereas apoA5 was positively correlated with serum TG in hypertriglyceridemic controls (TG> or =150mg/dL, n=268) (r=0.246, P<0.001) and total CAD patients (r=0.177, P<0.01). Regardless of TG levels and CAD status, apoA5 concentration was positively correlated with HDL-cholesterol and FFA levels. Our data supports an inverse association between plasma apoA5 concentrations and CAD risk, probably due to the observed negative correlations of apoA5 with TGs and insulin, although these correlations were affected by TG levels. Show less

The association between -1131T>C single nucleotide polymorphism (SNP) of the apolipoprotein A5 gene (APOA5) and hypertriglyceridemia raised the possibility that this SNP could be related to coronary artery disease (CAD) risk. Therefore, we investigated the association of this APOA5 -1131T>C SNP with circulating concentrations of APOA5, triglyceride and CAD in Koreans. CAD patients (n=741) and age-, sex-matched healthy controls (n=741) were genotyped for the APOA5 -1131T>C SNP. The main outcome measures were the odds ratio (OR) on CAD risk and lipid variables, APOA5 concentration and LDL particle size. The presence of the minor allele at the -1131T>C SNP was associated with an increased risk of CAD [OR 1.34 (95% CI, 1.09-1.65), P=0.007] after adjusting for BMI, alcohol consumption, systolic blood pressure and diastolic blood pressure. There was an association between the APOA5 concentration and the -1131T>C genotype in controls (T/T: 245+/-7 ng/ml, T/C: 220+/-6, C/C: 195+/-12; P=0.001) and CAD patients (T/T: 218+/-8 ng/ml, T/C: 185+/-7, C/C: 169+/-12; P<0.001). Subjects with T/C or C/C in control and CAD patient groups showed higher triglyceride than those with T/T genotype. Also, the -1131T>C polymorphism was associated with LDL particle size (P=0.003), with the T/C or C/C controls having smaller size than the T/T controls. The APOA5 -1131C allele is associated with reduced APOA5 concentration and with increased CAD risk. This is consistent with the observed association between the -1131C SNP, increased triglycerides as well as small LDL particle size. Show less

The gene expression profiles of lysophosphatidic acid (LPA)-treated young and senescent human diploid fibroblasts (HDFs) were examined using cDNA microarray analysis. The expression of some genes, including EGR 1/3 and MRRF, was controlled by LPA similarly in young and senescent cells, showing a typical time-dependent up-and-down expression profile. In contrast, some other genes, including DUSP6, CYR61, and F3, showed sustained upregulation in senescent HDFs later after LPA treatment. These genes might be involved in altered LPA responsiveness during the aging process. Show less

Recent studies using human and mice reported that apolipoprotein A-V (APOA5) gene plays an important role in controlling triglyceride (TG) concentrations. The purpose of the present study was to investigate the correlation between single nucleotide polymorphisms (SNPs) and haplotypes in the APOA5 gene and TG in subjects and to search for possible associations of the APOA5 gene variants and common haplotypes with hypertriglyceridemia (HTG). We examined the case-control subjects including 100 HTG patients and 243 unrelated healthy control. The genes were screened for SNPs by direct sequencing in 48 genetically unrelated individuals. Six SNPs (-1390C>T, -1020G>A, -3A>G, V150M, G182C and 1259T>C) were genotyped in case and control populations. In this study, our results indicated a strong association between APOA5 SNP -3A>G and G182C and elevated TG levels (p<0.001). Analysis of the SNPs from APOA5 gene has identified major haplotype showing very strong association with HTG, CGGGTT (p<0.001). Likelihood ratio test (LRT) of these six SNPs revealed that haplotypes were strong independent predictors of HTG (p<0.001). Haplotype-trend logistic regression (HTR) analysis revealed a significant association between the CGGGGC (haplotype 2) and CGGGTT (haplotype 4) and HTG (OR=2.48, 95% CI=1.06-5.76 and OR=8.54, 95% CI=2.66-27.42, respectively). We confirm that the APOA5 variants are associated with triglyceride levels and the haplotype may be strong independent predictors of HTG among Koreans. Show less

The purpose of this study was to compare low-fat (LF) meal and high-fat (HF) meal on the postprandial lipemic responses according to the -1131T>C polymorphism of the APOA5 gene in a population usually consuming a LF diet and having a high frequency of the variant allele at the APOA5 -1131T>C SNP. This study was conducted using a cross-over design and 49 non-obese healthy men (42.8 +/- 0.7 yrs, 23.9 +/- 0.25 kg/m(2)) participated in the meal tolerance test. They were randomly assigned to consume one of two types of experimental enteral formulae (LF vs HF) with a seven-day interval. Blood samples were collected at 0, 2, 3, 4 and 6h after ingestion and analyzed for total and chylomicron TG, glucose, insulin and free fatty acid. No differences were found in anthropometic parameter, calorie and macronutrient intakes and total energy expenditure between TT (n = 23) and TC + CC (n = 26) men. Fasting total TG were higher in TC + CC men than TT men, but fasting chylomicron TG were not significantly different between TT men and C carriers, TT subjects had no significant differences in postprandial responses of total TG and chylomicron TG and postprandial mean changes of chylomicron TG between LF and HF meal. On the other hand, C carriers had delayed peak time of total TG compared to TT subject and higher postprandial response and mean changes of chylomicron TG at HF meal compared to LF meal. The capacity to clear chylomicron-TG or hydrolyze TG might become a rate-limiting factor on HF diet in TC + CC men resulting in higher postprandial triglyceridemia. Therefore, HF diet for C carriers of the APOA5 gene may be one of important CVD risk factors. Show less

Apolipoprotein A5 plays an important role in modulating triacylglycerol metabolism in experimental animal models. The objective was to determine associations of the common apolipoprotein A5 gene (APOA5) -1131T-->C polymorphism with postprandial lipemic response and other cardiovascular disease risk factors in humans. Healthy, nonobese subjects [n = 158; mean (+/-SEM) age: 33.8 +/- 1.2 y; body mass index (in kg/m(2)): 23.3 +/- 0.3] were subdivided into 3 genotype groups: TT (n = 85), TC (n = 56), and CC (n = 17). We measured fasting and postprandial lipid concentrations, lipid peroxidation, C-reactive protein concentrations, and DNA damage. Fasting triacylglycerol concentrations in carriers of the C allele were higher (P < 0.05) than in carriers of the TT genotype. No other significant genotype-related differences were observed for any of the other baseline measures. After consumption of a mixed meal, carriers of the C allele had significantly greater increases in total chylomicron and VLDL triacylglycerol than did subjects with the TT genotype. Moreover, carriers of the C allele had higher dense LDL, serum C-reactive protein, and urinary 8-epi-prostaglandin F(2alpha) concentrations and more lymphocyte DNA damage. Conversely, we did not find significant genotype-related differences in postprandial glucose, insulin, or free fatty acid measures. Our data confirm the genetic modulation of serum fasting triacylglycerol concentrations by the APOA5 gene polymorphism and extend this observation to postprandial triacylglycerol concentrations and to markers of oxidation and inflammation. The presence of the C allele in the APOA5 promoter region at position 1131 could be a significant factor contributing to higher cardiovascular disease risk in Koreans independently of common environmental factors. Show less