👤 Minshik Chae

Diabetes is a major risk factor for diabetic encephalopathy (DE), which is closely associated with sporadic Alzheimer's disease. Folic acid (FA) receptor signaling can suppress generation of neuropathogenic amyloid-beta (Aβ) induced by high extracellular glucose, suggesting that enhanced activation of this pathway could be a therapeutic strategy against DE-associated dementia, but the precise molecular signaling mechanisms are unclear. We report that high glucose levels increased the expression of amyloid precursor protein (APP) and β-secretase (BACE1) in cultured neurons and concomitantly induced amyloidogenesis, while FA treatment suppressed high glucose-stimulated expression of APP and BACE1, Aβ release, and accumulation of mitochondrial reactive oxygen species. Expression of nuclear factor erythroid 2-related factor 2 (Nrf2) was minimal under high glucose conditions, but was significantly upregulated together with downstream antioxidant enzymes following FA co-treatment. High glucose stimulation also increased folate receptor 1 (FOLR1) mRNA expression, suggesting a compensatory protective response. While treatment with 5-methyltetrahydrofolate (5-MTHF), the activated form of folate, did not significantly alter high glucose-induced upregulation of APP and BACE1, knockdown of FOLR1 mRNA reduced high glucose-stimulated Nrf2 expression and further augmented APP and BACE1 expression under high glucose conditions. Treatment with the STAT3 inhibitor 5'15-DPP also abolished high glucose-stimulated Nrf2 expression and increased APP and BACE1 expression levels. These findings indicate that FA/FOLR1 activation suppresses high glucose-induced amyloidogenesis by mitigating mitochondrial oxidative stress via STAT3/Nrf2 pathway signaling. In conclusion, present study suggests that the FA/FOLR1/STAT3/Nrf2 pathway is an effective therapeutic target for DE. Show less

Most cancer cells adopt a less efficient metabolic process of aerobic glycolysis with high level of glucose uptake followed by lactic acid production, known as the Warburg effect. This phenotypic transition enables cancer cells to achieve increased cellular survival and proliferation in a harsh low-oxygen tumor microenvironment. Also, the resulting acidic microenvironment causes inactivation of the immune system such as T-cell impairment that favors escape by immune surveillance. While lots of studies have revealed that tumor-derived EVs can deliver parental materials to adjacent cells and contribute to oncogenic reprogramming, their functionality in energy metabolism is not well addressed. In this study, we established prostate cancer cells PC-3AcT resistant to cellular death in an acidic culture medium driven by lactic acid. Quantitative proteomics between EVs derived from PC-3 and PC-3AcT cells identified 935 confident EV proteins. According to cellular adaptation to lactic acidosis, we revealed 159 regulated EV proteins related to energy metabolism, cellular shape, and extracellular matrix. These EVs contained a high abundance of glycolytic enzymes. In particular, PC-3AcT EVs were enriched with apolipoproteins including apolipoprotein B-100 (APOB). APOB on PC-3AcT EVs could facilitate their endocytic uptake depending on low density lipoprotein receptor of recipient PC-3 cells, encouraging increases of cellular proliferation and survival in acidic culture media via increased activity and expression of hexokinases and phosphofructokinase. The activation of recipient PC-3 cells can increase glucose consumption and ATP generation, representing an acquired metabolic reprogramming into the Warburg phenotype. Our study first revealed that EVs derived from prostate cancer cells could contribute to energy metabolic reprogramming and that the acquired metabolic phenotypic transition of recipient cells could favor cellular survival in tumor microenvironment. Show less

Alzheimer's disease (AD) is a multifactorial neurodegenerative disorder characterized by cognitive decline, anxiety-like behavior, β-amyloid (Aβ) accumulation, and tau hyperphosphorylation. BACE1, the enzyme critical for Aβ production, has been a major therapeutic target; however, direct BACE1 inhibition has been associated with adverse side effects. This study investigates the therapeutic potential of RA-PR058, a novel ramalin derivative, as a multi-targeted modulator of AD-related pathologies. The effects of RA-PR058 were evaluated Show less

Alzheimer's disease (AD) is the most common type of dementia. Its incidence is rising rapidly as the global population ages, leading to a significant social and economic burden. AD involves complex pathologies, including amyloid plaque accumulation, synaptic dysfunction, and neuroinflammation. This study explores the therapeutic potential of N Show less

Effective intracellular delivery of therapeutic proteins can potentially treat a wide array of diseases. However, efficient delivery of functional proteins across the cell membrane remains challenging. Exosomes are nanosized vesicles naturally secreted by various types of cells and may serve as promising nanocarriers for therapeutic biomolecules. Here, we engineered exosomes equipped with a photoinducible cargo protein release system, termed mMaple3-mediated protein loading into and release from exosome (MAPLEX), in which cargo proteins can be loaded into the exosomes by fusing them with photocleavable protein (mMaple3)-conjugated exosomal membrane markers and subsequently released from the exosomal membrane by inducing photocleavage with blue light illumination. Using this system, we first induced transcriptional regulation by delivering octamer-binding transcription factor 4 and SRY-box transcription factor 2 to fibroblasts in vitro. Second, we induced in vivo gene recombination in Cre reporter mice by delivering Cre recombinase. Last, we achieved targeted epigenome editing in the brains of 5xFAD and 3xTg-AD mice, two models of Alzheimer's disease. Administration of MAPLEXs loaded with β-site amyloid precursor protein cleaving enzyme 1 ( Show less

We recently reported that the dopamine (DA) analogue CA140 modulates neuroinflammatory responses in lipopolysaccharide-injected wild-type (WT) mice and in 3-month-old 5xFAD mice, a model of Alzheimer's disease (AD). However, the effects of CA140 on Aβ/tau pathology and synaptic/cognitive function and its molecular mechanisms of action are unknown. To investigate the effects of CA140 on cognitive and synaptic function and AD pathology, 3-month-old WT mice or 8-month-old (aged) 5xFAD mice were injected with vehicle (10% DMSO) or CA140 (30 mg/kg, i.p.) daily for 10, 14, or 17 days. Behavioral tests, ELISA, electrophysiology, RNA sequencing, real-time PCR, Golgi staining, immunofluorescence staining, and western blotting were conducted. In aged 5xFAD mice, a model of AD pathology, CA140 treatment significantly reduced Aβ/tau fibrillation, Aβ plaque number, tau hyperphosphorylation, and neuroinflammation by inhibiting NLRP3 activation. In addition, CA140 treatment downregulated the expression of cxcl10, a marker of AD-associated reactive astrocytes (RAs), and c1qa, a marker of the interaction of RAs with disease-associated microglia (DAMs) in 5xFAD mice. CA140 treatment also suppressed the mRNA levels of s100β and cxcl10, markers of AD-associated RAs, in primary astrocytes from 5xFAD mice. In primary microglial cells from 5xFAD mice, CA140 treatment increased the mRNA levels of markers of homeostatic microglia (cx3cr1 and p2ry12) and decreased the mRNA levels of a marker of proliferative region-associated microglia (gpnmb) and a marker of lipid-droplet-accumulating microglia (cln3). Importantly, CA140 treatment rescued scopolamine (SCO)-mediated deficits in long-term memory, dendritic spine number, and LTP impairment. In aged 5xFAD mice, these effects of CA140 treatment on cognitive/synaptic function and AD pathology were regulated by dopamine D1 receptor (DRD1)/Elk1 signaling. In primary hippocampal neurons and WT mice, CA140 treatment promoted long-term memory and dendritic spine formation via effects on DRD1/CaMKIIα and/or ERK signaling. Our results indicate that CA140 improves neuronal/synaptic/cognitive function and ameliorates Aβ/tau pathology and neuroinflammation by modulating DRD1 signaling in primary hippocampal neurons, primary astrocytes/microglia, WT mice, and aged 5xFAD mice. Show less

Plants have evolved strategies to cope with drought stress by maximizing physiological capacity and adjusting developmental processes such as flowering time. The WOX13 orthologous group is the most conserved among the clade of WOX homeodomain-containing proteins and is found to function in both drought stress and flower development. In this study, we isolated and characterized Show less

Hypertriglyceridemia is recognized as an independent risk factor for coronary artery disease. The apolipoprotein A5 gene (APOA5) is a key regulator of triglyceride levels. We aimed to evaluate the associations of single nucleotide polymorphisms (SNPs) in APOA5, including -1131T>C and c.553G>T, with hypertriglyceridemia, apoA5 concentrations, atherogenic LDL cholesterol levels, and arterial stiffness in hypertriglyceridemic patients. The study population included 599 hypertriglyceridemic patients (case) and 1,549 untreated normotriglyceridemic subjects (control). We genotyped two APOA5 variants, -1131T>C (rs662799) and c.553G>T (rs2075291). The frequencies of the CC genotype of -1131T>C (0.165) and the T allele of c.553G>T (0.119) were significantly higher in hypertriglyceridemic patients than in normotriglyceridemic subjects (0.061 and 0.070, respectively; all p<0.001). In the control and case groups, both the -1131T>C and c.553G>T variants were associated with higher triglyceride and lower HDL cholesterol levels. Controls with the -1131CC variant had lower apoA5 concentrations than controls with the -1131TT variant. Similar effects of the -1131T>C variant on apoA5 were observed in the cases. In the hypertriglyceridemic group, the -1131T>C variant was associated with a smaller LDL particle size, higher levels of oxidized LDL and malondialdehyde, and higher brachial-ankle pulse wave velocity. The -1131T>C and c.553G>T polymorphisms were associated with hypertriglyceridemia in the study population, but only the -1131T>C polymorphism directly affected apoA5 concentrations. Hypertriglyceridemic patients carrying the APOA5 -1131T>C polymorphism exhibited increased atherogenic LDL levels and arterial stiffness, probably due to an effect of the -1131T>C polymorphism on apoA5 concentrations. 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

Previous studies have indicated that supplementation with probiotics might improve lipid metabolism. The objective of the study was to evaluate the effect of supplementation with probiotic strains Lactobacillus curvatus (L. curvatus) HY7601 and Lactobacillus plantarum (L. plantarum) KY1032 on triglyceride (TG) and apolipoprotein A-V (apo A-V) levels. A randomized, double-blinded, placebo-controlled study was conducted with 128 non-diabetic subjects with hypertriglyceridemia. Over a 12-week test period, the probiotic group consumed 2 g/day of a powdered supplement containing L. curvatus HY7601 and L. plantarum KY1032, whereas the placebo group consumed a powder lacking probiotics. After the treatment, the probiotic group showed an 18.3% (P < 0.001) reduction in TGs and increases of 21.1% (P = 0.001) and 15.6% (P < 0.001) in the apo A-V and LDL particle size, respectively. The probiotic group had a significant reduction in TGs (P = 0.040) and increases in the plasma apo A-V (P = 0.003) and LDL particle size (P < 0.001) compared with the placebo group. In the probiotic group, the reduction in the TG levels was negatively correlated with changes in the apo A-V and baseline TGs, regardless of the APOA5 -1131T > C genotype. The consumption of two probiotic strains for 12 weeks reduced TGs and increased the apo A-V and LDL particle size in hypertriglyceridemic subjects. This effect was more pronounced in subjects with higher levels of fasting TGs regardless of their APOA5 -1131T > C genotype. Show less

The purpose of this study was to estimate the effects of a 3-year dietary intervention on age-related changes in triglyceride and apolipoprotein (apo A-V) levels in patients with impaired fasting glucose (IFG) or new-onset type 2 diabetes as a function of the APOA5 -1131 T > C polymorphism. We genotyped the APOA5 -1131 T > C polymorphism in 203 Korean individuals with IFG or new-onset type 2 diabetes for the TT (n = 91), TC (n = 98), and CC (n = 14) alleles. Plasma apo A-V and triglyceride levels were evaluated at baseline and after a 3-year dietary intervention. Our results showed that HDL, glucose, insulin, HOMA-IR index, free fatty acids, and apo A-V decreased and brachial-ankle pulse wave velocity (ba-PWV) and malondialdehyde (MDA) increased at the 3-year follow-up visit compared with baseline. Plasma apo A-V levels were reduced in subjects with the C allele (TC or CC) (P = 0.036) and triglyceride levels were reduced in subjects with the TT allele (P = 0.047). Subjects with the C allele showed lower post-treatment apo A-V and higher post-treatment fasting triglyceride levels than subjects with the TT allele. Changes in apo A-V and triglyceride levels were negatively correlated in subjects with the TT allele and positively correlated in subjects with the C allele. This study showed that the dietary intervention prevented an age-related increase in triglyceride levels in individuals with IFG or new-onset type 2 diabetes who possess the TT allele, but not the CT or CC allele, of the APOA5 -1131 T > C polymorphism. Show less

The apolipoprotein A5 gene (APOA5) -1131 T > C polymorphism is associated with mild hypertriglyceridemia in type 2 diabetic subjects, and interacts with dietary fat in the determination of triglyceride concentrations. We examined whether a substitution of whole grains and legumes for refined rice in a high carbohydrate diet (about 65% of energy derived from carbohydrate) may modify the effect of this variant on changes in apolipoprotein A-V (apoA-V) and triglyceride concentrations. We genotyped the APOA5 -1131 T > C in individuals with impaired fasting glucose (IFG) or newly diagnosed type 2 diabetes, who were randomly assigned to either a group ingesting whole grain and legume meals daily or a control group for 12 weeks. After dietary intervention, we observed significant interactions between the APOA5 -1131 T > C polymorphism and carbohydrate sources (whole grains and legumes versus refined rice) in the determination of mean percent changes in triglyceride and apoA-V (P interactions <0.001 and =0.038, respectively). In the refined rice group (n = 93), the carriers of the risk C allele (n = 50) showed a greater increase in the mean percent changes of triglyceride and apoA-V than noncarriers after adjusting for HOMA-IR (P = 0.004 and 0.021, respectively). The whole grain and legume group (n = 92), however, showed a decrease in fasting glucose, HOMA-IR, and triglyceride, and an increase in apoA-V, irrespective of genotype. The data showed that the magnitude of the genetic effect of the APOA5 -1131C variant on triglyceride and apoA-V levels was modulated when substituting consumption of whole grains and legumes for refined rice as a carbohydrate source in IFG or diabetic subjects. ClinicalTrials.gov: NCT01784952. Show less

We aimed to elucidate the effect of bilirubin on dyslipidemia and nephropathy in a diabetes mellitus (DM) type I animal model. Sprague-Dawley rats were separated into control, DM, and bilirubin-treated DM (Bil) groups. The Bil group was injected intraperitoneally with 60 mg/kg bilirubin 3 times per week and hepatoma cells were cultured with bilirubin at a concentration of 0.3 mg/dL. The Bil group showed lower serum creatinine levels 5 weeks after diabetes onset. Bilirubin treatment also decreased the amount of mesangial matrix, lowered the expression of renal collagen IV and transforming growth factor (TGF)-β1, and reduced the level of apoptosis in the kidney, compared to the DM group. These changes were accompanied by decreased tissue levels of hydrogen superoxide and NADPH oxidase subunit proteins. Bilirubin decreased serum total cholesterol, high-density lipoprotein cholesterol (HDL-C), free fatty acids, and triglycerides (TGs), as well as the TG content in the liver tissues. Bilirubin suppressed protein expression of LXRα, SREBP-1, SCD-1, and FAS, factors involved in TG synthesis that were elevated in the livers of DM rats and hepatoma cells under high-glucose conditions. In conclusion, bilirubin attenuates renal dysfunction and dyslipidemia in diabetes by suppressing LXRα and SREBP-1 expression and oxidative stress. Show less

The perturbation of the steady state of reactive oxygen species (ROS) due to biotic and abiotic stresses in a plant could lead to protein denaturation through the modification of amino acid residues, including the oxidation of methionine residues. Methionine sulfoxide reductases (MSRs) catalyze the reduction of methionine sulfoxide back to the methionine residue. To assess the role of this enzyme, we generated transgenic rice using a pepper CaMSRB2 gene under the control of the rice Rab21 (responsive to ABA protein 21) promoter with/without a selection marker, the bar gene. A drought resistance test on transgenic plants showed that CaMSRB2 confers drought tolerance to rice, as evidenced by less oxidative stress symptoms and a strengthened PSII quantum yield under stress conditions, and increased survival rate and chlorophyll index after the re-watering. The results from immunoblotting using a methionine sulfoxide antibody and nano-LC-MS/MS spectrometry suggest that porphobilinogen deaminase (PBGD), which is involved in chlorophyll synthesis, is a putative target of CaMSRB2. The oxidized methionine content of PBGD expressed in E. coli increased in the presence of H2O2, and the Met-95 and Met-227 residues of PBGD were reduced by CaMSRB2 in the presence of dithiothreitol (DTT). An expression profiling analysis of the overexpression lines also suggested that photosystems are less severely affected by drought stress. Our results indicate that CaMSRB2 might play an important functional role in chloroplasts for conferring drought stress tolerance in rice. Show less

To investigate the association of FADS gene polymorphisms with age-related changes in polyunsaturated fatty acids (PUFAs) in serum phospholipids and oxidative stress markers. We genotyped 122 nonobese men aged 35-59 years without any known diseases at baseline for rs174537 near FADS1 (FEN1 rs174537G > T), FADS2 (rs174575, rs2727270), and FADS3 (rs1000778), and followed them for 3 years. Among the four single-nucleotide polymorphisms, the minor variants of rs174537 and rs2727270 were significantly associated with lower concentrations of long-chain PUFAs. However, rs174537G > T showed stronger association. At baseline, men with the rs174537T allele had lower arachidonic acid (AA) and AA/linoleic acid (LA), and higher interleukin (IL)-6 levels than rs174537GG counterparts. After 3 years, rs174537GG men had significantly increased AA (P = 0.022), AA/dihomo-γ-linolenic acid (DGLA) (P = 0.007), docosapentaenoic acid (DPA), low-density lipoprotein (LDL) cholesterol, and oxidized LDL (ox-LDL), but decreased eicosatrienoic acid. The rs174537T group showed significantly increased γ-linolenic acid and ox-LDL, and decreased eicosadienoic acid, eicosapentaenoic acid (EPA)/α-linolenic acid (ALA), and IL-6. After 3 years, the rs174537T group had lower AA (P < 0.001), AA/DGLA (P = 0.019), EPA, DPA, EPA/ALA, and urinary 8-epi-prostaglandin F2α (8-epi-PGF2α) (P = 0.011) than rs174537GG. Changes in AA (P = 0.001), AA/DGLA (P = 0.017), EPA, DPA, EPA/ALA, and urinary 8-epi-PGF2α (P < 0.001) were significantly different between the groups after adjusting for baseline values. Overall, changes in AA positively correlated with changes in urinary 8-epi-PGF2α (r = 0.249, P = 0.007), plasma ox-LDL (r = 0.199, P = 0.045), and serum IL-6 (r = 0.289, P = 0.004). Our data show that FADS polymorphisms can affect age-associated changes in serum phospholipid long-chain PUFAs, Δ5-desaturase activity, and oxidative stress in middle-aged nonobese men. In particular, the rs174537T allele did not show the age-associated increases in AA and Δ5-desaturase activity seen with the rs174537GG genotype. Show less

We investigated the relationship between fatty acid desaturase (FADS) gene polymorphisms and insulin resistance (IR) in association with serum phospholipid polyunsaturated fatty acid (FA) composition in healthy Korean men. Healthy men (n = 576, 30 ~ 79 years old) were genotyped for rs174537 near FADS1 (FEN1-10154G>T), FADS2 (rs174575C>G, rs2727270C>T), and FADS3 (rs1000778C>T) SNPs. Dietary intake, serum phospholipid FA composition and HOMA-IR were measured. Fasting insulin and HOMA-IR were significantly higher in the rs174575G allele carriers than the CC homozygotes, but lower in the rs2727270T allele carriers than the CC homozygotes. The proportion of linoleic acid (18:2ω-6, LA) was higher in the minor allele carriers of FEN1-10154G>T, rs174575C>G and rs2727270C>T than the major homozygotes, respectively. On the other hand, the proportions of dihomo-γ-linolenic acid (20:3ω-6, DGLA) and arachidonic acid (20:4ω-6, AA) in serum phospholipids were significantly lower in the minor allele carriers of FEN1-10154 G>T carriers and rs2727270C>T than the major homozygotes respectively. AA was also significantly lower in the rs1000778T allele carriers than the CC homozygotes. HOMA-IR positively correlated with LA and DGLA and negatively with AA/DGLA in total subjects. Interestingly, rs174575G allele carriers showed remarkably higher HOMA-IR than the CC homozygotes when subjects had higher proportions of DLGA (≥1.412% in total serum phospholipid FA composition) (P for interaction = 0.009) or of AA (≥4.573%) (P for interaction = 0.047). HOMA-IR is associated with FADS gene cluster as well as with FA composition in serum phospholipids. Additionally, HOMA-IR may be modulated by the interaction between rs174575C>G and the proportion of DGLA or AA in serum phospholipids. 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

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 cholesteryl ester transfer protein (CETP), a key player in cholesterol metabolism, has been shown to promote the transfer of triglycerides from very low density lipoprotein (VLDL) and low density lipoprotein (LDL) to high density lipoprotein (HDL) in exchange for cholesterol ester. Here we demonstrate that farnesoid X receptor alpha (FXRalpha; NR1H4) down-regulates CETP expression in HepG2 cells. A FXRalpha ligand, chenodeoxycholic acid (CDCA), suppressed basal mRNA levels of the CETP gene in HepG2 cells in a dose-dependent manner. Using gel shift and chromatin immunoprecipitation (ChIP) assays, we found that FXRalpha could bind to the liver X receptor alpha (LXRalpha; NR1H3) binding site (LXRE; DR4RE) located within the CETP 5' promoter region. FXRalpha suppressed LXRalpha-induced DR4RE-luciferase activity and this effect was mediated by a binding competition between FXRalpha and LXRalpha for DR4RE. Furthermore, the addition of CDCA together with a LXRalpha ligand, GW3965, to HepG2 cells was shown to substantially decrease mRNA levels of hepatic CETP gene, which is typically induced by GW3965. Together, our data demonstrate that FXRalpha down-regulates CETP gene expression via binding to the DR4RE sequence within the CETP 5' promoter and this FXRalpha binding is essential for FXRalpha inhibition of LXRalpha-induced CETP expression. Show less