👤 Hyun-Dong Paik

The prevalence of neurodegenerative disorders continues to increase with population aging. Brain-derived neurotrophic factor is a biomarker of cognitive function and neuroprotection. Lactobacillus plantarum C29-fermented soybean (DW2009) has been suggested to enhance cognition by modulating brain-derived neurotrophic factor. This secondary analysis of a randomized, double-blind, placebo-controlled trial investigated the influence of sociodemographic and lifestyle factors on serum brain-derived neurotrophic factor responsiveness to DW2009 supplementation. One hundred adults (age: 55-85 years) with mild cognitive impairment were randomized 1:1 to receive DW2009 (800 mg/day) or placebo (800 mg/day) for 12 weeks. The participants were examined, and their cognitive clinical features and serum brain-derived neurotrophic factor (BDNF) levels were measured at baseline and after a 12-week period. We found that DW2009 significantly increased serum BDNF levels, especially in older men (≥ 68 years) and in those with lower educational attainment (≤ 11 years). Subgroup analysis also indicated that the effect of DW2009 was enhanced in participants who performed frequent physical activity (≥ 5 times/week) and those within the normal body mass index range (18.5-22.9 kg/m²). Our findings suggest that the increase in serum BDNF after DW2009 supplementation is dependent on baseline characteristics, although this interpretation requires confirmation. DW2009 intake was linked to increased serum BDNF levels in individuals with specific sociodemographic and lifestyle characteristics. These findings suggest that personalized supplementation strategies may optimize functional benefits for cognitive health. Show less

The effects of ovomucoid (OVM), a by-product of egg white, and its hydrolysates on adipocyte differentiation and lipid accumulation were investigated. The OVM hydrolyzed using Alcalase® and pepsin was named AH and PH, respectively. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis analysis revealed significant changes in molecular weight of both hydrolysates, with AH showing a higher degree of hydrolysis. AH exhibited a more pronounced inhibitory effect on fat accumulation than PH. In in vitro experiments, AH and PH suppressed lipid accumulation during 3T3-L1 adipocyte differentiation, with AH inhibiting lipid accumulation most effectively. Oil red O staining and triglyceride measurements revealed lipid reduction in AH-treated cells, indicating that AH plays a major role in preventing lipid accumulation in adipocytes. In addition, AH inhibited the expression of lipid transcription factors (CCAAT/enhancer-binding protein alpha (C/EBP-α), peroxisome proliferator-activated receptor gamma (PPAR-γ), and sterol regulatory element-binding proteins (SREBP-1c)), adipogenesis-related factors (fatty acid synthase (FAS) and ACC1), insulin-related factors (insulin receptor substrate (IRS2) and protein kinase B (AKT2)), and lipolysis-related factors (glycerol-3-phosphate acyltransferase (GPAT), CD36, and lipoprotein lipase (LPL)) in a concentration-dependent manner. Specifically, the effect of AH was most pronounced in the early stages of adipocyte differentiation, where it activated AMPK early to associate energy homeostasis and downregulate genes important for cell cycle and lipid formation. This study suggests that OVM hydrolysates prepared using Alcalase® may contribute to the development of new strategies for the obesity treatment market. Show less

Observational studies have suggested associations between dietary polyunsaturated fatty acids (PUFAs) and cancer risk; however, causal inference regarding skin cancer remains limited due to potential recall bias, confounding, and reverse causation. This study aimed to evaluate the causal association between genetically predicted circulating PUFA levels and the risk of skin cancers, including basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and melanoma. We conducted a 2-sample Mendelian randomization (MR) study using genome-wide association study summary statistics from the UK Biobank (PUFAs, n=115,006) and the FinnGen consortium (BCC, n=26,272; SCC, n=4,663; melanoma, n=5,753). Genetic instruments were derived for omega-3, docosahexaenoic acid, omega-6, linoleic acid, and the omega-6:3 ratio. Multiple MR methods-including inverse-variance weighted, MR-Egger, weighted median, weighted mode, and MR-PRESSO-were applied to test for consistency and assess pleiotropy and heterogeneity. A higher genetically predicted linoleic acid to total fatty acid ratio was associated with a significantly lower risk of BCC and SCC. Conversely, higher genetically proxied serum omega-3 levels were associated with increased risks of BCC, SCC, and melanoma. The risk effect on SCC was attenuated upon exclusion of rs174528, a variant in the fatty acid desaturase 1 ( This MR analysis supports a causal role of circulating PUFAs in skin cancer development and highlights the importance of FADS-mediated endogenous PUFA metabolism. These findings provide novel insights into the genetic and metabolic underpinnings of skin cancer susceptibility. Show less

Physical activity has been considered an important non-medication intervention in preserving mnemonic processes during aging. However, how aerobic exercise promotes such benefits for human health remains unclear. In this study, we aimed to explore the neuroprotective and anti-inflammatory effects of aerobic exercise against lipopolysaccharide (LPS)-induced amnesic C57BL/6J mice and BV-2 microglial cell models. In the in vivo experiment, the aerobic exercise training groups were allowed to run on a motorized treadmill 5 days/week for 4 weeks at a speed of 10 rpm/min, with LPS (0.1 mg/kg) intraperitoneally injected once a week for 4 weeks. We found that aerobic exercise ameliorated memory impairment and cognitive deficits among the amnesic mice. Correspondingly, aerobic exercise significantly increased the protein expressions of FNDC5, which activates target neuroprotective markers BDNF and CREB, and antioxidant markers Nrf2/HO-1, leading to inhibiting microglial-mediated neuroinflammation and reduced the expression of BACE-1 in the hippocampus and cerebral cortex of amnesic mice. We estimated that aerobic exercise inhibited neuroinflammation in part through the action of FNDC5/irisin on microglial cells. Therefore, we explored the anti-inflammatory effects of irisin on LPS-stimulated BV-2 microglial cells. In the in vitro experiment, irisin treatment blocked NF-κB/MAPK/IRF3 signaling activation concomitantly with the significantly lowered levels of the LPS-induced iNOS and COX-2 elevations and promotes the Nrf2/HO-1 expression in the LPS-stimulated BV-2 microglial cells. Together, our findings suggest that aerobic exercise can improve the spatial learning ability and cognitive functions of LPS-treated mice by inhibiting microglia-mediated neuroinflammation through its effect on the expression of BDNF/FNDC5/irisin. Show less

Myositis is a heterogeneous family of diseases that includes dermatomyositis (DM), antisynthetase syndrome (AS), immune-mediated necrotising myopathy (IMNM), inclusion body myositis (IBM), polymyositis and overlap myositis. Additional subtypes of myositis can be defined by the presence of myositis-specific autoantibodies (MSAs). The purpose of this study was to define unique gene expression profiles in muscle biopsies from patients with MSA-positive DM, AS and IMNM as well as IBM. RNA-seq was performed on muscle biopsies from 119 myositis patients with IBM or defined MSAs and 20 controls. Machine learning algorithms were trained on transcriptomic data and recursive feature elimination was used to determine which genes were most useful for classifying muscle biopsies into each type and MSA-defined subtype of myositis. The support vector machine learning algorithm classified the muscle biopsies with >90% accuracy. Recursive feature elimination identified genes that are most useful to the machine learning algorithm and that are only overexpressed in one type of myositis. For example, CAMK1G (calcium/calmodulin-dependent protein kinase IG), EGR4 (early growth response protein 4) and CXCL8 (interleukin 8) are highly expressed in AS but not in DM or other types of myositis. Using the same computational approach, we also identified genes that are uniquely overexpressed in different MSA-defined subtypes. These included apolipoprotein A4 (APOA4), which is only expressed in anti-3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) myopathy, and MADCAM1 (mucosal vascular addressin cell adhesion molecule 1), which is only expressed in anti-Mi2-positive DM. Unique gene expression profiles in muscle biopsies from patients with MSA-defined subtypes of myositis and IBM suggest that different pathological mechanisms underly muscle damage in each of these diseases. Show less

Melanogenesis is a physiological process that results in the synthesis of melanin pigments, which play a crucial protective role against skin photocarcinogenesis. We investigated the effects of a Polygoni Multiflori Ramulus extract on melanogenesis and isolated emodin from Polygoni Multiflori as an active compound. In addition, the possible mechanisms of action were examined. We found that emodin inhibited both melanin content and tyrosinase activity concentration and time dependently. Tyrosinase, tyrosinase-related protein (TRP)-1, and TRP-2 mRNA levels decreased following emodin treatment. However, while the mRNA levels of microphthalmia-associated transcription factor (MITF) were not affected by emodin, emodin reduced MITF protein levels. Furthermore, expression of the liver X-receptor (LXR) α gene, but not the LXR β gene was upregulated by emodin. Moreover, emodin regulated melanogenesis by promoting degradation of the MITF protein by upregulating the LXR α gene. The emodin effects on MITF was found to be mediated by phosphorylation of p42/44 MAPK. Taken together, these findings indicate that the inhibition of melanogenesis by emodin occurs through reduced MITF protein expression, which is mediated by upregulation of the LXR α gene and suggest that emodin may be useful as a hyperpigmentation inhibitor. Show less

The relationship between the apolipoprotein A5 gene (APOA5) -1131T>C polymorphism and triglyceride levels is well established, but the association between circulating apolipoprotein A-V (apoA-V) concentrations and APOA5 -1131T>C genotypes and triglyceride levels remains controversial. Normotriglyceridemic controls (n = 1526) and hypertriglyceridemic cases (n = 744) were genotyped for APOA5-1131T>C. ApoA-V, triglycerides, insulin, free fatty acids, and lipoprotein profiles were analyzed. APOA5-1131C minor allele frequency was significantly greater in hypertriglyceridemic patients than normotriglyceridemic controls. ApoA-V concentrations were not significantly different between controls and cases. Normotriglyceridemic controls with T/C and C/C showed lower apoA-V concentrations (14% and 27%, respectively), than did T/T controls. Similar genotypic effects on apoA-V were found in hypertriglyceridemic cases. In both groups, APOA5-1131T>C was associated with higher triglycerides, smaller LDL particle size, and lower HDL-cholesterol. We observed a negative correlation between apoA-V and triglyceride in controls and a positive correlation in hypertriglyceridemic patients, regardless of genotype. We observed a positive correlation between apoA-V and free fatty acids in both groups, regardless of genotype, and a positive correlation between apoA-V and HDL-cholesterol in controls (T/T, T/C, or C/C) and hypertriglyceridemic patients (T/T or T/C). APOA5-1131C may lead to reduced apoA-V with concomitantly reduced lipoprotein lipase activation, resulting in greater serum triglycerides, although the correlation between apoA-V and triglyceride was reversed when triglyceride was greater than 150 mg/dL. 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 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

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