Association between DNA methylation levels of thioredoxin-interacting protein (TXNIP) and changes in glycemic traits: a longitudinal population-based study.

Thioredoxin-interacting protein (TXNIP) plays an important role in glucose metabolism, and its expression is regulated by DNA methylation (DNAm). Although the association between TXNIP DNAm and type 2 diabetes mellitus has been demonstrated in studies with a cross-sectional design, prospective studies are needed. We therefore examined the association between TXNIP DNAm levels and longitudinal changes in glycemic traits by conducting a longitudinal study involving 169 subjects who underwent two health checkups in 2015 and 2019. We used a pyrosequencing assay to determine TXNIP DNAm levels in leukocytes (cg19693031). Logistic regression analyses were performed to assess the associations between dichotomized TXNIP DNAm levels and marked increases in glycemic traits. At four years, the TXNIP DNA hypomethylation group had a higher percentage of changes in fasting plasma glucose (FPG) and hemoglobin A1c (HbA1c) compared to those in the hypermethylation group. The adjusted odds ratios for FPG and HbA1c levels were significantly higher in the TXNIP DNA hypomethylation group than in the hypermethylation group. We found that TXNIP DNA hypomethylation at baseline was associated with a marked increase in glycemic traits. Leukocyte TXNIP DNAm status could potentially be used as an early biomarker for impaired glucose homeostasis.

Serum carotenoid levels are positively associated with DNA methylation of thioredoxin-interacting protein.

Background: Carotenoids have been reported to exert protective effects against age-related diseases via changes in DNA methylation. Although lower thioredoxin-interacting protein (TXNIP) DNA methylation is associated with age-related diseases, only a few studies have investigated the factors influencing TXNIP DNA methylation. Carotenoids may be a factor linking TXNIP to specific pathophysiological functions. The aim of this study was to examine whether serum carotenoid levels are associated with TXNIP DNA methylation levels. Methods: We conducted a cross-sectional study using 376 health examination participants (169 men). DNA methylation levels were determined using a pyrosequencing assay. Serum carotenoid levels were determined by high-performance liquid chromatography. Multivariable regression analyses were performed to examine the associations between TXNIP DNA methylation levels and serum carotenoid levels with adjustment for age, BMI, HbA1c, CRP, smoking habits, alcohol consumption, exercise habits, and percentage of neutrophils. Results: Multiple linear regression analyses showed that TXNIP DNA methylation levels were positively associated with serum levels of zeaxanthin/lutein (ß [95%CI]: 1.935 [0.184, 3.685]), ß-cryptoxanthin (1.447 [0.324, 2.570]), α-carotene (1.061 [0.044, 2.077]), ß-carotene (1.272 [0.319, 2.226]), total carotenes (1.255 [0.040, 2.469]), total xanthophylls (2.133 [0.315, 3.951]), provitamin A (1.460 [0.402, 2.519]), and total carotenoids (1.972 [0.261, 3.683]) in men (all p<0.05). Of these, provitamin A showed the stronger association (standardized ß=0.216). No significant association of TXNIP DNA methylation and serum carotenoid was observed in women. Conclusions: The findings of this study suggest that carotenoid intake may protect against age-related diseases by altering TXNIP DNA methylation status in men.

Neuron-derived neurotrophic factor protects against dexamethasone-induced skeletal muscle atrophy.

Skeletal muscle atrophy caused by various conditions including aging, nerve damage, and steroid administration, is a serious health problem worldwide. We recently reported that neuron-derived neurotrophic factor (NDNF) functions as a muscle-derived secreted factor, also known as myokine, which exerts protective actions on endothelial cell and cardiomyocyte function. Here, we investigated whether NDNF regulates skeletal muscle atrophy induced by steroid administration and sciatic denervation. NDNF-knockout (KO) mice and age-matched wild-type (WT) mice were subjected to continuous dexamethasone (DEX) treatment or sciatic denervation. NDNF-KO mice exhibited decreased gastrocnemius muscle weight and reduced cross sectional area of myocyte fiber after DEX treatment or sciatic denervation compared with WT mice. Administration of an adenoviral vector expressing NDNF (Ad-NDNF) or recombinant NDNF protein to gastrocnemius muscle of WT mice increased gastrocnemius muscle weight after DEX treatment. NDNF-KO mice showed increased expression of ubiquitin E3-ligases, including atrogin-1 and MuRF-1, in gastrocnemius muscle after DEX treatment, whereas Ad-NDNF reduced expression of atrogin-1 and MuRF-1 in gastrocnemius muscle of WT mice after DEX treatment. Pretreatment of cultured C2C12 myocytes with NDNF protein reversed reduced myotube diameter and increased expression of atrogin-1 and MuRF-1 after DEX stimulation. Treatment of C2C12 myocytes increased Akt phosphorylation. Pretreatment of C2C12 myotubes with the PI3-kinase/Akt inhibitor reversed NDNF-induced increase in myotube fiber diameter after DEX treatment. In conclusion, our findings indicated that NDNF prevents skeletal muscle atrophy in vivo and in vitro through reduction of ubiquitin E3-ligases expression, suggesting that NDNF could be a novel therapeutic target of muscle atrophy.

Maternal fructose intake predisposes rat offspring to metabolic disorders via abnormal hepatic programming.

Given that fructose consumption has increased by more than 10-fold in recent decades, it is possible that excess maternal fructose consumption causes harmful effects in the next generation. This study attempted to elucidate the mechanism of the harmful effects of excessive maternal fructose intake from the perspective of offspring liver function. Female rats during gestation and lactation were fed water containing fructose, and their offspring were fed normal water. We attempted to elucidate the mechanism of fructose-induced transgenerational toxicity by conducting a longitudinal study focusing on hepatic programming prior to disease onset. Impaired Insulin resistance and decreased high-density lipoprotein-cholesterol levels were observed at 160 days of age. However, metabolic disorders were not observed in 60-day-old offspring. Microarray analysis of 60-day-old offspring livers showed the reduction of hepatic insulin-like growth factor-1 (Igf1) mRNA expression. This reduction continued until the rats were aged 160 days and attenuated Igf1 signaling. Hepatic microRNA-29 (miR-29a) and miR-130a, which target Igf1 mRNA, were also found to be upregulated. Interestingly, these miRNAs were upregulated in the absence of metabolic disorder. In this study, we found that maternal fructose intake resulted in dysregulated expression of Igf1 and its target miRNAs in the offspring liver, and that these offspring were more likely to develop metabolic disorders. Abnormal hepatic programming induced by an imbalanced maternal nutritional environment is maintained throughout life, implying that it may contribute to metabolic disorders.

LPL/AQP7/GPD2 promotes glycerol metabolism under hypoxia and prevents cardiac dysfunction during ischemia.

In the heart, fatty acid is a major energy substrate to fuel contraction under aerobic conditions. Ischemia downregulates fatty acid metabolism to adapt to the limited oxygen supply, making glucose the preferred substrate. However, the mechanism underlying the myocardial metabolic shift during ischemia remains unknown. Here, we show that lipoprotein lipase (LPL) expression in cardiomyocytes, a principal enzyme that converts triglycerides to free fatty acids and glycerol, increases during myocardial infarction (MI). Cardiomyocyte-specific LPL deficiency enhanced cardiac dysfunction and apoptosis following MI. Deficiency of aquaporin 7 (AQP7), a glycerol channel in cardiomyocytes, increased the myocardial infarct size and apoptosis in response to ischemia. Ischemic conditions activated glycerol-3-phosphate dehydrogenase 2 (GPD2), which converts glycerol-3-phosphate into dihydroxyacetone phosphate to facilitate adenosine triphosphate (ATP) synthesis from glycerol. Conversely, GPD2 deficiency exacerbated cardiac dysfunction after acute MI. Moreover, cardiomyocyte-specific LPL deficiency suppressed the effectiveness of peroxisome proliferator-activated receptor alpha (PPARα) agonist treatment for MI-induced cardiac dysfunction. These results suggest that LPL/AQP7/GPD2-mediated glycerol metabolism plays an important role in preventing myocardial ischemia-related damage.

Important Role of Concomitant Lymphangiogenesis for Reparative Angiogenesis in Hindlimb Ischemia.

[Figure: see text].

Circulating microRNA-27a and -133a are negatively associated with incident hypertension: a five-year longitudinal population-based study.

BACKGROUND: Previous cross-sectional studies have shown that several circulating microRNA levels are associated with hypertension, but there are no prospective studies among general populations. OBJECTIVE: We evaluated the impact of circulating inflammatory- and oxidative stress-responsive microRNAs on changes in blood pressure and the development of hypertension in normotensive Japanese. METHOD: The study subjects were 84 normotensive participants (33 men and 51 women) who were given a health examination in both 2012 and 2017. In five years, 29 participants developed hypertension. Serum levels of miRNAs (miR-21, miR-27a, and miR-133a) were measured using qRT-PCR. Odds ratios (ORs) and 95% confidence intervals (CIs) for incident hypertension were estimated by logistic regression analysis. RESULTS: Serum miR-27a and -133a levels were lower in newly hypertensive subjects compared with normotensive subjects. With 1-unit lower serum miR-27a and -133a, the confounders adjusted ORs and 95% CI for incident hypertension were 0.84 (0.72-0.96) and 0.75 (0.58-0.91), respectively. The group with high levels of serum miR-27a and -133a had lower ORs than the group with low levels of these miRNAs (OR and 95% CI of miR-27a: 0.29, 0.08-0.91; miR-133a: 0.08, 0.01-0.37, respectively). CONCLUSIONS: Circulating miR-27a and -133a are potential biomarkers for the prediction and prevention of hypertension.

Increased brain-derived neurotrophic factor in the serum of persons with nonalcoholic fatty liver disease.

The increasing prevalence of nonalcoholic fatty liver disease (NAFLD) is a global health problem. In recent years, the inhibitory effect of brain-derived neurotrophic factor (BDNF) on diabetes mellitus and fatty liver has been clarified. The purpose of this study was to analyze the relationship between serum BDNF and NAFLD which caused by abnormal metabolism of glucose and lipids. This cross-sectional study involved 429 participants (mean age, 63.5 years: men, 38.5%) with low alcohol intake. Of the participants, those who had an increase in echogenicity of the liver parenchyma and hepato-renal contrast on ultrasonography were classified as the NAFLD group (n = 88), and the others were classified as the normal (n = 341) group. The NAFLD group was further classified into a mild group (n = 60) and a severe group (n = 28) based on the intensity of echogenicity and visualization of the hepatic vessels and diaphragm. Median BDNF levels were higher in the NAFLD group than the normal group (35.5 vs. 42.3 ng/mL, p < 0.01). Furthermore, BDNF levels tended to be associated with the severity of NAFLD (p < 0.01). In addition to the univariate analysis, in the sex- and age-adjusted model, there was a significant association between the BDNF levels and NAFLD severity (p < 0.01). The fully adjusted regression analysis also showed a positive association between the serum BDNF level and NAFLD (p < 0.01). These results suggest that NAFLD patients have a compensatory increase in circulating BDNF levels.

DNA methylation level of the gene encoding thioredoxin-interacting protein in peripheral blood cells is associated with metabolic syndrome in the Japanese general population.

Metabolic syndrome (MetS) is cluster of metabolic diseases, including abdominal obesity, hyperglycemia, high blood pressure, and dyslipidemia, that directly escalate the risk of type 2 diabetes, heart disease, and stroke. Thioredoxin-interacting protein (TXNIP) is a binding protein for thioredoxin, a molecule that is a key inhibitor of cellular oxidation, and thus regulates the cellular redox state. Epigenetic alteration of the TXNIP-encoding locus has been associated with components of MetS. In the present study, we sought to determine whether the level of TXNIP methylation in blood is associated with MetS in the general Japanese population. DNA was extracted from the peripheral blood cells of 37 subjects with and 392 subjects without MetS. The level of TXNIP methylation at cg19693031 was assessed by the bisulfite-pyrosequencing method. We observed that TXNIP methylation levels were lower in MetS subjects (median 74.9%, range 71.7-78.4%) than in non-MetS subjects (median 77.7%, range 74.4-80.5%; p = 0.0024). Calculation of the confounding factor-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for hypomethylation revealed that subjects with MetS exhibited significantly higher ORs for hypomethylation than did those without MetS (OR, 2.92; 95% CI, 1.33-6.62; p = 0.009). Our findings indicated that lower levels of TXNIP methylation are associated with MetS in the general Japanese population. Altered levels of DNA methylation in TXNIP at cg19693031 might play an important role in the pathogenesis of MetS.

Association between the Extent of Peripheral Blood DNA Methylation of HIF3A and Accumulation of Adiposity in community-dwelling Women: The Yakumo Study.

INTRODUCTION: DNA methylation in the CpG sites of intron 1 of HIF3A is associated with body mass index (BMI). This cross-sectional study investigated correlations between DNA methylation of HIF3A and BMI or adiposity parameters in the Japanese population. METHOD: DNA methylation of HIF3A was quantified via pyrosequencing. RESULT: DNA methylation of HIF3A differed only in women; DNA methylation level at cg27146050 was associated with visceral adipose tissue thickness and correlated with BMI and percent (%) body fat after excluding smokers. CONCLUSION: Peripheral blood DNA methylation at the CpG site (cg27146050) of HIF3A correlated with VAT thickness in Japanese women.

Association of drinking behaviors with TXNIP DNA methylation levels in leukocytes among the general Japanese population.

Background: Thioredoxin-interacting protein (TXNIP) controls the cellular redox balance by binding to and inhibiting the expression and function of thioredoxin. DNA methylation of the TXNIP gene is involved in the regulation of TXNIP mRNA expression. Changes in TXNIP DNA methylation levels are associated with the development of various diseases such as type 2 diabetes mellitus (T2DM). However, few studies have focused on the influence of lifestyle factors such as alcohol intake on TXNIP DNA methylation.Objectives: This research examines the association of drinking behaviors with TXNIP DNA methylation levels in the general Japanese population.Methods: We conducted a cross-sectional study of 404 subjects (176 males and 228 females) who were divided into non-, moderate and heavy drinkers based on self-reported drinking behaviors. TXNIP DNA methylation levels in leukocytes were determined using a pyrosequencing assay.Results: The mean TXNIP DNA methylation level in heavy drinkers (74.2%) was significantly lower than that in non- and moderate drinkers (non: 77.7%, p < .001; moderate: 76.6%, p = .011). Multivariable linear regression analysis showed that log-transformed values of daily (b = -1.34; p < .001) and cumulative (b = -1.06; p = .001) alcohol consumption were associated with decreased TXNIP DNA methylation levels.Conclusion: TXNIP DNA methylation levels in heavy drinkers was lower than in non- and- moderate drinkers. Decreased TXNIP DNA methylation level increases the expression of TXNIP and elevates the risk of developing of diseases such as T2DM. Therefore, decreasing alcohol use in heavy drinkers may lessen the likelihood of some alcohol-related illnesses moderated through TXNIP DNA methylation.

Orally administered octacosanol improves some features of high fructose-induced metabolic syndrome in rats.

We examined whether orally administered octacosanol, a long-chain aliphatic saturated alcohol, improves the features of high fructose-induced metabolic syndrome in rats. Five-week-old rats were fed a high fructose diet containing 60% fructose for 3 weeks. Then, the high fructose fed rats received a daily single oral administration of octacosanol (10 or 100 mg/kg body weight) with high fructose feeding for one week. Three- or four-week high fructose feeding increased insulin resistance, serum insulin, triglyceride, total cholesterol, free fatty acids, uric acid, and lipid peroxide concentrations, and hepatic triglyceride and cholesterol contents significantly and decreased serum high-density lipoprotein cholesterol and adiponectin concentrations significantly but did not affect blood pressure and hepatic lipid peroxide and reduced glutathione contents. Four-week high fructose feeding decreased hepatic ascorbic acid content significantly. Oral administration of octacosanol (10 or 50 mg/kg body weight) to high fructose-fed rats for the last 1-week fructose diet feeding attenuated these changes except serum insulin level and insulin resistance significantly and increased hepatic reduced glutathione content significantly. The higher dose of Oct decreased hepatic lipid peroxide content significantly. These results indicate that orally administered octacosanol improves dyslipidemia, hyperuricemia, hypoadiponectinemia, and oxidative stress associated with the features of high fructose-induced metabolic syndrome rats.

Cardiomyocytes capture stem cell-derived, anti-apoptotic microRNA-214 via clathrin-mediated endocytosis in acute myocardial infarction.

Extracellular vesicles (EVs) have emerged as key mediators of intercellular communication that have the potential to improve cardiac function when used in cell-based therapy. However, the means by which cardiomyocytes respond to EVs remains unclear. Here, we sought to clarify the role of exosomes in improving cardiac function by investigating the effect of cardiomyocyte endocytosis of exosomes from mesenchymal stem cells on acute myocardial infarction (MI). Exposing cardiomyocytes to the culture supernatant of adipose-derived regenerative cells (ADRCs) prevented cardiomyocyte cell damage under hypoxia in vitro. In vivo, the injection of ADRCs into the heart simultaneous with coronary artery ligation decreased overall cardiac infarct area and prevented cardiac rupture after acute MI. Quantitative RT-PCR-based analysis of the expression of 35 known anti-apoptotic and secreted microRNAs (miRNAs) in ADRCs revealed that ADRCs express several of these miRNAs, among which miR-214 was the most abundant. Of note, miR-214 silencing in ADRCs significantly impaired the anti-apoptotic effects of the ADRC treatment on cardiomyocytes in vitro and in vivo To examine cardiomyocyte endocytosis of exosomes, we cultured the cardiomyocytes with ADRC-derived exosomes labeled with the fluorescent dye PKH67 and found that hypoxic culture conditions increased the levels of the labeled exosomes in cardiomyocytes. Chlorpromazine, an inhibitor of clathrin-mediated endocytosis, significantly suppressed the ADRC-induced decrease of hypoxia-damaged cardiomyocytes and also decreased hypoxia-induced cardiomyocyte capture of both labeled EVs and extracellular miR-214 secreted from ADRCs. Our results indicate that clathrin-mediated endocytosis in cardiomyocytes plays a critical role in their uptake of circulating, exosome-associated miRNAs that inhibit apoptosis.

Protein Kinase N Promotes Stress-Induced Cardiac Dysfunction Through Phosphorylation of Myocardin-Related Transcription Factor A and Disruption of Its Interaction With Actin.

BACKGROUND: Heart failure is a complex syndrome that results from structural or functional impairment of ventricular filling or blood ejection. Protein phosphorylation is a major and essential intracellular mechanism that mediates various cellular processes in cardiomyocytes in response to extracellular and intracellular signals. The RHOA-associated protein kinase (ROCK/Rho-kinase), an effector regulated by the small GTPase RHOA, causes pathological phosphorylation of proteins, resulting in cardiovascular diseases. RHOA also activates protein kinase N (PKN); however, the role of PKN in cardiovascular diseases remains unclear. METHODS: To explore the role of PKNs in heart failure, we generated tamoxifen-inducible, cardiomyocyte-specific PKN1- and PKN2-knockout mice by intercrossing the αMHC-CreERT2 line with Pkn1flox/flox and Pkn2flox/flox mice and applied a mouse model of transverse aortic constriction- and angiotensin II-induced heart failure. To identify a novel substrate of PKNs, we incubated GST-tagged myocardin-related transcription factor A (MRTFA) with recombinant GST-PKN-catalytic domain or GST-ROCK-catalytic domain in the presence of radiolabeled ATP and detected radioactive GST-MRTFA as phosphorylated MRTFA. RESULTS: We demonstrated that RHOA activates 2 members of the PKN family of proteins, PKN1 and PKN2, in cardiomyocytes of mice with cardiac dysfunction. Cardiomyocyte-specific deletion of the genes encoding Pkn1 and Pkn2 (cmc-PKN1/2 DKO) did not affect basal heart function but protected mice from pressure overload- and angiotensin II-induced cardiac dysfunction. Furthermore, we identified MRTFA as a novel substrate of PKN1 and PKN2 and found that MRTFA phosphorylation by PKN was considerably more effective than that by ROCK in vitro. We confirmed that endogenous MRTFA phosphorylation in the heart was induced by pressure overload- and angiotensin II-induced cardiac dysfunction in wild-type mice, whereas cmc-PKN1/2 DKO mice suppressed transverse aortic constriction- and angiotensin II-induced phosphorylation of MRTFA. Although RHOA-mediated actin polymerization accelerated MRTFA-induced gene transcription, PKN1 and PKN2 inhibited the interaction of MRTFA with globular actin by phosphorylating MRTFA, causing increased serum response factor-mediated expression of cardiac hypertrophy- and fibrosis-associated genes. CONCLUSIONS: Our results indicate that PKN1 and PKN2 activation causes cardiac dysfunction and is involved in the transition to heart failure, thus providing unique targets for therapeutic intervention for heart failure.

Maternal fructose-induced oxidative stress occurs viaTfam and Ucp5 epigenetic regulation in offspring hippocampi.

Fructose consumption is rising globally, but maternal high fructose intake might adversely affect offspring. Our previous report demonstrated that excess maternal fructose intake impairs hippocampal function in offspring, indicating that the hippocampi of offspring are highly sensitive to maternal fructose. Here, we examined the effect of maternal high fructose on mitochondrial physiology and uncoupling protein (UCP) expression. Rat dams received a 20% fructose solution during gestation and lactation. Immediately after weaning, offspring hippocampi were isolated. Maternal high fructose consumption attenuated the mitochondrial O2 consumption rate and stimulated lipid hydroperoxide production in the hippocampi of offspring. Reduced Ucp5 and mitochondrial transcription factor A (Tfam) mRNA levels were also observed after maternal exposure to fructose. We assessed the promoter regions of both genes and found that this treatment enhanced DNA methylation levels. In addition, luciferase assays showed that this DNA methylation could reduce the transcription of both genes. Chromatin immunoprecipitation analysis demonstrated that specificity protein 1 binding to the Ucp5 promoter regions was reduced by DNA methylation. In addition, Ucp5 knockdown induced the up-regulation of reactive oxygen species levels in a rat brain glioma cell line, whereas reduced O2 consumption was observed with Tfam knockdown. Maternal high fructose intake thus induces reduced O2 oxygen consumption and increases oxidative stress in offspring, at least partly through epigenetic mechanisms involving Ucp5 and Tfam.-Yamada, H., Munetsuna, E., Yamazaki, M., Mizuno, G., Sadamoto, N., Ando, Y., Fujii, R., Shiogama, K., Ishikawa, H., Suzuki, K., Shimono, Y., Ohashi, K., Hashimoto, S. Maternal fructose-induced oxidative stress occurs viaTfam and Ucp5 epigenetic regulation in offspring hippocampi.

Myonectin Is an Exercise-Induced Myokine That Protects the Heart From Ischemia-Reperfusion Injury.

RATIONALE: Physical exercise provides benefits for various organ systems, and some of systemic effects of exercise are mediated through modulation of muscle-derived secreted factors, also known as myokines. Myonectin/C1q (complement component 1q)/TNF (tumor necrosis factor)-related protein 15/erythroferrone is a myokine that is upregulated in skeletal muscle and blood by exercise. OBJECTIVE: We investigated the role of myonectin in myocardial ischemic injury. METHODS AND RESULTS: Ischemia-reperfusion in myonectin-knockout mice led to enhancement of myocardial infarct size, cardiac dysfunction, apoptosis, and proinflammatory gene expression compared with wild-type mice. Conversely, transgenic overexpression of myonectin in skeletal muscle reduced myocardial damage after ischemia-reperfusion. Treadmill exercise increased circulating myonectin levels in wild-type mice, and it reduced infarct size after ischemia-reperfusion in wild-type mice, but not in myonectin-knockout mice. Treatment of cultured cardiomyocytes with myonectin protein attenuated hypoxia/reoxygenation-induced apoptosis via S1P (sphingosine-1-phosphate)-dependent activation of cAMP/Akt cascades. Similarly, myonectin suppressed inflammatory response to lipopolysaccharide in cultured macrophages through the S1P/cAMP/Akt-dependent signaling pathway. Moreover, blockade of S1P-dependent pathway reversed myonectin-mediated reduction of myocardial infarct size in mice after ischemia-reperfusion. CONCLUSIONS: These data indicate that myonectin functions as an endurance exercise-induced myokine which ameliorates acute myocardial ischemic injury by suppressing apoptosis and inflammation in the heart, suggesting that myonectin mediates some of the beneficial actions of exercise on cardiovascular health.

Associations of Circulating MicroRNAs (miR-17, miR-21, and miR-150) and Chronic Kidney Disease in a Japanese Population.

BACKGROUND: MicroRNAs (miRNAs) play crucial roles in the development of various diseases, including chronic kidney disease (CKD). Although previous studies in clinically severe patients have investigated associations between CKD and miRNAs, with particular attention on renal fibrosis, relationships in a general population have yet to be established. The aim of this study was to examine the relationship between expression level of circulating miRNAs and CKD in a middle-aged Japanese population. METHODS: A final total of 513 individuals (216 men and 297 women) who participated in the health check-up program in 2012 were included in our analysis. Quantitative real-time polymerase chain reaction was used to determine expression levels of 22 miRNAs. Estimated glomerular filtration rate (eGFR) was calculated based on serum creatinine level, sex, and age. Participants with eGFR <60 mL/min/1.73 m2 were defined as having CKD. RESULTS: Three different miRNAs (miR-17, miR-21, and miR-150) showed significant correlations with eGFR after Bonferroni correction and were selected for further analyses. Expression levels of miR-17, miR-21, and miR-150 miRNAs were positively associated with eGFR after adjusting for potential confounders (P = 0.004, 0.002, and 0.004, respectively). Logistic regression analyses showed significantly lower odds ratios for CKD (eGFR <60 mL/min/1.73 m2) in the highest tertile of all three miRNAs (miR-17, miR-21, and miR-150) compared with the lowest tertile (P = 0.003, 0.01, and 0.02, respectively). CONCLUSIONS: We found that three circulating miRNAs were significantly associated with CKD in a general Japanese population, which suggested that these miRNAs may be biomarkers for CKD among general adults.

Excess maternal fructose consumption impairs hippocampal function in offspring via epigenetic modification of BDNF promoter.

Recent increases in fructose consumption have raised concerns about the potential adverse intergenerational effects of excess fructose intake. In the present study, we investigated whether excess maternal fructose intake affects hippocampal function in offspring. Female Sprague-Dawley rats were divided into 3 experimental groups: one group received distilled water, one group received 20% fructose water, and one group received 20% glucose water in addition to standard chow during gestation and lactation. Hippocampal function of offspring was evaluated by using novel object recognition and fear conditioning tests. Impaired cognitive performance was observed in the offspring of fructose-fed dams at postnatal d 60, potentially a result of decreased hippocampal neurogenesis. Real-time PCR analysis demonstrated that offspring from fructose-fed dams exhibited decreased brain-derived neurotrophic factor ( BDNF) gene expression, whereas pyrosequencing assays revealed increased DNA methylation at the BDNF promoter. The potential association between BDNF transcription and levels of DNA methylation was confirmed on the basis of luciferase activity. Furthermore, longitudinal analysis revealed that increased methylation of the BDNF promoter region was maintained at least until rats reached maturity. These results indicate that epigenetic changes associated with BDNF may underlie hippocampal dysfunction that is induced by early-life exposure to excess maternal fructose consumption.-Yamazaki, M., Yamada, H., Munetsuna, E., Ishikawa, H., Mizuno, G., Mukuda, T., Mouri, A., Nabeshima, T., Saito, K., Suzuki, K., Hashimoto, S., Ohashi, K. Excess maternal fructose consumption impairs hippocampal function in offspring via epigenetic modification of BDNF promoter.

Circulating microRNAs (miR-126, miR-197, and miR-223) are associated with chronic kidney disease among elderly survivors of the Great East Japan Earthquake.

BACKGROUND: A recent study has reported that incidence of chronic kidney disease (CKD) is higher in evacuees, but the molecular mechanism still remains unclear. One plausible hypothesis is a change in vascular function following to psychological distress. In order to assess molecular mechanisms underlying this association, we examined whether cardiovascular disease (CVD)-associated miRNAs (miR-126, miR-197, and miR-223) were associated with CKD among Japanese elderly survivors after an earthquake. METHODS: We analyzed 1385 individuals (670 men and 715 women) who participated in a post-disaster health check-up after the Great East Japan Earthquake, which occurred in 2011. The check-up involved collection of information about lifestyle, clinical history, the degree of housing damage, and baseline measurement of the estimated glomerular filtration rate. Expression levels of miRNAs were determined using real-time polymerase chain reaction. Estimated glomerular filtration rate (eGFR) was calculated using sex, age, and serum creatinine. CKD was defined as eGFR < 60 ml/min/1.73m2. The multivariable regression analyses were performed to examine the associations between CVD-associated miRNAs and CKD after adjusting potential confounders. RESULTS: Mean age (standard deviation) of participants with normal kidney function and CKD was 62.7 (10.6) and 71.9 (8.1) years, respectively. Expression levels of these miRNAs in participants with CKD were significantly lower than normal kidney function (all p < 0.001). Even after adjusting for lifestyle, clinical profiles, and psychological distress, significant associations between three miRNAs and CKD still remained. A significant linear association between the cumulative score of these miRNAs and CKD was found (p = 0.04). CONCLUSIONS: This cross-sectional study suggested that CVD-associated miRNAs were an important factor of CKD in an elderly Japanese population after earthquake. Future studies need to examine this association in longitudinal dataset.

C1q/TNF-related protein-1 functions to protect against acute ischemic injury in the heart.

Obesity is associated with an increased risk of cardiovascular disease. C1q/TNF-related protein (CTRP)-1 is a poorly characterized adipokine that is up-regulated in association with ischemic heart disease. We investigated the role of CTRP1 in myocardial ischemia injury. CTRP1-knockout mice showed increased myocardial infarct size, cardiomyocyte apoptosis, and proinflammatory gene expression after I/R compared with wild-type (WT) mice. In contrast, systemic delivery of CTRP1 attenuated myocardial damage after I/R in WT mice. Treatment of cardiomyocytes with CTRP1 led to reduction of hypoxia-reoxygenation-induced apoptosis and lipopolysaccharide-stimulated expression of proinflammatory cytokines, which was reversed by inhibition of sphingosine-1-phosphate (S1P) signaling. Treatment of cardiomyocytes with CTRP1 also resulted in the increased production of cAMP, which was blocked by suppression of S1P signaling. The antiapoptotic and anti-inflammatory actions of CTRP1 were cancelled by inhibition of adenylyl cyclase or knockdown of adiponectin receptor 1. Furthermore, blockade of S1P signaling reversed CTRP1-mediated inhibition of myocardial infarct size, apoptosis, and inflammation after I/R in vivo. These data indicate that CTRP1 protects against myocardial ischemic injury by reducing apoptosis and inflammatory response through activation of the S1P/cAMP signaling pathways in cardiomyocytes, suggesting that CTRP1 plays a crucial role in the pathogenesis of ischemic heart disease.