Dietary Exposure to Antibiotic Residues Facilitates Metabolic Disorder by Altering the Gut Microbiota and Bile Acid Composition.

Antibiotics used as growth promoters in livestock and animal husbandry can be detected in animal-derived food. Epidemiological studies have indicated that exposure to these antibiotic residues in food may be associated with childhood obesity. Herein, the effect of exposure to a residual dose of tylosin-an antibiotic growth promoter-on host metabolism and gut microbiota was explored in vivo. Theoretical maximal daily intake (TMDI) doses of tylosin were found to facilitate high-fat-diet-induced obesity, induce insulin resistance, and perturb gut microbiota composition in mice. The obesity-related phenotypes were transferrable to germfree recipient mice, indicating that the effects of a TMDI dose of tylosin on obesity and insulin resistance occurred mainly via alteration of the gut microbiota. Tylosin TMDI exposure restricted to early life, the critical period of gut microbiota development, altered the abundance of specific bacteria related to host metabolic homeostasis later in life. Moreover, early-life exposure to tylosin TMDI doses was sufficient to modify the ratio of primary to secondary bile acids, thereby inducing lasting metabolic consequences via the downstream FGF15 signaling pathway. Altogether, these findings demonstrate that exposure to very low doses of antibiotic residues, whether continuously or in early life, could exert long-lasting effects on host metabolism by altering the gut microbiota and its metabolites. IMPORTANCE This study demonstrates that even with limited exposure in early life, a residual dose of tylosin might cause long-lasting metabolic disturbances by altering the gut microbiota and its metabolites. Our findings reveal that the gut microbiota is susceptible to previously ignored environmental factors.

Differences in the gut microbiome and reduced fecal butyrate in elders with low skeletal muscle mass.

BACKGROUND AND AIMS: Despite animal studies revealing a causal link between the gut microbiota and skeletal muscle mass, the role of the gut microbiome and its metabolites in humans having low muscle mass remains unclear. METHODS: Eighty-eight subjects older than 65 years were measured for sarcopenia-related parameters, including body composition, grip strength, gait speed and flexibility. Participants were divided into normal muscle mass group (NM, n = 52) and low muscle mass group (LM, n = 36) and fresh fecal samples were collected for metagenome and short chain fatty acids (SCFAs) analysis. RESULTS: The richness and evenness of gut microbiota diversity were significantly decreased in the subjects with low muscle mass, including observed ASVs, Shannon and Chao 1 index. A significant difference of gut microbiota profile was noted between NM group and LM group. The Firmicutes/Bacteroidetes ratio was significantly reduced in the LM group. A significant decrease in the abundance of a SCFA-producer, Marvinbryantia spp., whereas a remarkable enrichment of a flavonoid degrader, Flavonifractor spp., was observed in the LM elders. Comparing with the NM group, the fecal butyrate significantly diminished in the LM group and correlated with skeletal muscle mass index. CONCLUSIONS: This is the first study that demonstrates the reduced fecal butyrate in elders with low muscle mass and highlights the associated gut microbiome changes. The identified gut microbial features and fecal butyrate level may serve as potential biomarkers for early detection of sarcopenic patients.

Associations between fibrinogen levels and the risk of cardiovascular disease and all-cause death: a cohort study from the Chin-Shan community in Taiwan.

OBJECTIVES: Although several studies have investigated the association between fibrinogen level and the risk of cardiovascular disease (CVD), few studies have been conducted in Asia. SETTING: We conducted a community-based prospective cohort study in the Chin-Shan community, Taiwan. PARTICIPANTS: A total of 2222 participants (54.6±11.9 years, 53.4% women, and 22.4 years of follow-up) who underwent plasma fibrinogen measurements and were without CVD at baseline were recruited, among which 735 participants with available C reactive protein (CRP) were included in the joint analysis of the association of fibrinogen and CRP levels with the risk of CVD. PRIMARY AND SECONDARY OUTCOME MEASURES: Fibrinogen and CRP levels were measured by clotting and high-sensitivity immunoturbidimetric assays, respectively. The study outcomes were CVD events and all-cause death. Our definition of CVD included both coronary artery disease (CAD) and stroke cases. Cox proportional hazards regression models were used to estimate the HRs and 95% CIs. RESULTS: Compared with the lowest quartile, participants with higher fibrinogen levels tended to have a higher risk of CAD (adjusted HR for the highest quartile=1.48 (95% CI 0.90 to 2.44); test for trend p=0.037) regardless of CRP level (adjusted HR=2.12 (95% CI 1.24 to 3.63) and 2.17 (95% CI 1.06 to 4.44) for high fibrinogen/low CRP and high fibrinogen/high CRP, respectively). The association was not observed for stroke (adjusted HR for the highest quartile=0.99 (95% CI 0.62 to 1.60); test for trend p=0.99) and was only observed for all-cause death among participants <65 years of age (adjusted HR for the highest quartile=1.47 (95% CI 1.11 to 1.95); test for trend p=0.004). CONCLUSIONS: Fibrinogen may be a potential risk factor for CAD but not for stroke. Further studies are necessary to clarify the differences in the role of fibrinogen levels on the risk of CVD between Asian and Western countries.

Urinary sodium excretion and the risk of CVD: a community-based cohort study in Taiwan.

Urinary Na excretion is a potential risk factor for CVD. However, the underlying biological mechanisms and effects of salt sensitivity are unclear. The purpose of this study was to characterise the relative contribution of biological factors to the Na-CVD association. A total of 2112 participants were enrolled in this study. Structured questionnaires and blood and urine samples were obtained. Twenty-four-hour Na excretion was estimated using a single overnight urine sample. Hypertension, the metabolic syndrome and overweight status were considered to indicate salt sensitivity. Cox proportional hazard models were used to investigate the effects of salt sensitivity on urinary Na excretion and CVD risk. The traditional mediation approach was used to calculate the proportion of mediation. The mean age (sd) of the 2112 participants was 54·5 (sd 12·2) years, and they were followed up for a mean of 14·1 (sd 8·1) years. Compared with those in the lowest quartile, the highest baseline urinary Na excretion (>4·2 g/24 h) was associated with a 43 % higher CVD risk (hazard ratio, 1·43; 95 % CI 1·02, 1·99). Participants with high urinary Na excretion, hypertension or the metabolic syndrome had a significantly high risk of CVD. The carotid intima-media thickness had the largest mediating effect (accounting for 35 % of the Na-CVD association), followed by systolic blood pressure (BP) (33 %), left ventricular mass (28 %) and diastolic BP (14 %). Higher urinary Na excretion increased the risk of CVD, which was explained largely by carotid media-thickness and systolic BP.

Statin-induced microRNAome alterations modulating inflammation pathways of peripheral blood mononuclear cells in patients with hypercholesterolemia.

Statins inhibit cholesterol biogenesis and modulate atheroma inflammation to reduce cardiovascular risks. Promoted by immune and non-immune cells, serum C-reactive protein (CRP) might be a biomarker suboptimal to assess inflammation status. Although it has been reported that statins modulated inflammation via microRNAs (miRNAs), evidence remains lacking on comprehensive profiling of statin-induced miRNAome alterations in immune cells. We recruited 19 hypercholesterolemic patients receiving 2 mg/day pitavastatin and 15 ones receiving 10 mg/day atorvastatin treatment for 12 weeks, and performed microarray-based profiling of 1733 human mature miRNAs in peripheral blood mononuclear cells (PBMCs) before and after statin treatment. Differentially expressed miRNAs were determined if their fold changes were >1.50 or <0.67, after validated using quantitative polymerase chain reaction (qPCR). The miRSystem and miTALOS platforms were utilized for pathway analysis. Of the 34 patients aged 63.7 ± 6.2 years, 27 were male and 19 were with coronary artery disease. We discovered that statins induced differential expressions of miR-483-5p, miR-4667-5p, miR-1244, and miR-3609, with qPCR-validated fold changes of 1.74 (95% confidence interval, 1.33-2.15), 1.61 (1.25-1.98), 1.61 (1.01-2.21), and 1.68 (1.19-2.17), respectively. The fold changes of the four miRNAs were not correlated with changes of low-density-lipoprotein cholesterol or CRP, after sex, age, and statin type were adjusted. We also revealed that RhoA and transforming growth factor-ß signaling pathways might be regulated by the four miRNAs. Given our findings, miRNAs might be involved in statin-induced inflammation modulation in PBMCs, providing likelihood to assess and reduce inflammation in patients with atherosclerotic cardiovascular diseases.

Association of heart rate trajectories with the risk of adverse outcomes in a community-based cohort in Taiwan.

Heart rate trajectory patterns integrate information regarding multiple heart rate measurements and their changes with time. Different heart rate patterns may exist in one population, and these are associated with different outcomes. Our study investigated the association of adverse outcomes with heart rate trajectory patterns. This was a prospective cohort study based on the Chin-Shan Community Cardiovascular Cohort in Taiwan. A total of 3,015 Chinese community residents aged > 35 years were enrolled in a prospective investigation of cardiovascular risk factors and outcomes from 1990 to 2013.The primary outcome was all-cause mortality, and the secondary outcome was a composite of coronary artery disease and cerebrovascular accidents. The following trajectory patterns were identified: stable, 61%; decreased, 5%; mildly increased, 32%; and markedly increased, 2%. During follow-up (median, 13.9 years), 557 participants died and 217 experienced secondary outcomes. The adjusted hazard ratios of primary and secondary outcomes for participants with a markedly increased trajectory pattern were 1.80 (95% CI [1.18-2.76]) and 1.45 (95% CI [0.67-3.12]), respectively, compared to those for participants with a stable trajectory pattern. A markedly increased heart rate trajectory pattern may be associated with all-cause mortality risks. Heart rate trajectory patterns demonstrated the utility of repeated heart rate measurements for risk assessment.

Association between Plasma N-6 Polyunsaturated Fatty Acids Levels and the Risk of Cardiovascular Disease in a Community-based Cohort Study.

Most studies support that saturated fatty acid replacement with polyunsaturated fatty acids (PUFAs) may reduce the risk of cardiovascular diseases (CVDs) and put emphasis on the effects of N-3 PUFAs. The reported relationships between N-6 PUFAs and CVD risks vary. We aimed to examine the associations between N-6 PUFA concentrations and CVD risks. In this community-based prospective cohort study on CVD-free patients at baseline (N = 1835, age: 60.6 ± 10.5 years, women: 44.5%), we measured the fatty acid concentrations in the blood using gas chromatography. Four hundred twenty-four participants developed CVDs during follow up. The total N-6 PUFA concentration was inversely associated with the CVD risk, with a 48% lower risk in the highest N-6 PUFA concentration quartile (hazard ratio = 0.52; P for trend <0.001). The estimated population attributable risk of N-6 PUFAs indicated that approximately 20.7% of CVD events would have been prevented if the plasma N-6 PUFA concentration had been higher than the median value. The total N-6 PUFA concentration presented the highest net reclassification improvement (NRI = 7.2%, P = 0.03) for predicting incident CVD. Further studies on N-6 PUFAs, diet habits, and their relationships with healthcare are warranted.

Differential effects of saturated fatty acids on the risk of metabolic syndrome: a matched case-control and meta-analysis study.

BACKGROUND: We investigated the association between plasma saturated fatty acids (SFAs) and the risk of metabolic syndrome among ethnic Chinese adults in Taiwan who attended a health check-up center. METHODS: A case-control study based on 1000 cases of metabolic syndrome and 1:1 matched control participants (mean age, 54.9 ±â€¯10.7 y; 36% females) were recruited. Metabolic syndrome was defined according to the criteria of the International Diabetes Federation. Gas chromatography was used to measure the distribution of fatty acids in plasma (% of total fatty acids). RESULTS: Even-chain SFAs, including 14:0, 16:0, and 18:0, were associated with metabolic syndrome; the adjusted odds ratio [OR] and 95% confidence interval [CI] per standard deviation [SD] difference was 3.32, [1.98-5.59]; however, very-long-chain SFAs, including 20:0, 21:0, 22:0, 23:0, and 24:0, were inversely associated with metabolic syndrome. The adjusted OR [95% CI] per SD difference was 0.67 [0.58-0.78]. The area under the receiver operative characteristic curve increased from 0.814 in the basic model to 0.815 (p = 0.54, compared with the basic model), 0.818 (p < 0.0001), and 0.820 (p < 0.0001) after adding odd-chain, even-chain, and very-long chain SFAs. A meta-analysis based on 12 studies showed that the summarized OR for type 2 diabetes mellitus was 1.16 [0.96-1.41] for the top versus bottom SFAs. CONCLUSIONS: Different carbon numbers of SFAs have been shown to have differential effects on the status of metabolic syndrome, implying that SFAs are not homogenous for the effects.

Eicosapentaenoic acid protects cardiomyoblasts from lipotoxicity in an autophagy-dependent manner.

BACKGROUND AND AIMS: The cardiovascular health benefits of eicosapentaenoic acid (EPA) have been demonstrated previously; however, the exact mechanism underlying them remains unclear. Our previous study found that lipotoxicity induced cardiomyocyte apoptosis via the inhibition of autophagy. Accordingly, in this study, we investigated whether EPA attenuated lipotoxicity-induced cardiomyocyte apoptosis through autophagy regulation. The role of EPA in mitochondrial dynamics was analyzed as well. METHODS: To explore how EPA protected against lipotoxicity-induced myocardial injury, cardiomyoblast (H9C2) cells were left untreated or were treated with 400 µM palmitic acid (PAM) and/or 80 µM EPA for 24 h. RESULTS: Excessive PAM treatment induced apoptosis. EPA reduced this PAM-induced apoptosis; however, EPA was unable to ameliorate the effects of PAM when autophagy was blocked by 3-methyladenine and bafilomycin A1. PAM blocked the autophagic flux, thus causing the accumulation of autophagosomes and acid vacuoles, whereas EPA restored the autophagic flux. PAM caused a decrease in polyunsaturated fatty acid (PUFA) content and an increase in saturated fatty acid content in the mitochondrial membrane, while EPA was incorporated in the mitochondrial membrane and caused a significant increase in the PUFA content. PAM also decreased the mitochondrial membrane potential, whereas EPA enhanced it. Finally, PAM elevated the expressions of autophagy-related proteins (LC3I, LC3II, p62) and mitochondrial fission protein (Drp1), whereas EPA inhibited their elevation under PAM treatment. CONCLUSIONS: EPA reduces lipotoxicity-induced cardiomyoblast apoptosis through its effects on autophagy.

Association between type 2 diabetes and cancer incidence in Taiwan: data from a prospective community-based cohort study.

AIMS: Evidence of a role for type 2 diabetes in overall cancer risk and risk for specific types of cancer is limited in ethnic Chinese populations. We therefore investigated whether there is an association between diabetes and cancer incidence in Taiwan. METHODS: This study recruited a total of 3602 adults aged 35 years or over (average 54.9 ± 12.3 years, 52.8% women). Participants with fasting glucose ≥126 mg/dL, or taking hypoglycemic medications, were classed as having type 2 diabetes. Cancer incidence was established through regular follow-up interviews and medical records. Cox proportional hazard regression models were used to examine associations for diabetes with risk of all-cause and site-specific cancers. RESULTS: During a median of follow-up of 10.5 years, 275 individuals developed cancer, including 157 digestive cancers and 31 urinary cancers. Younger participants (aged < 55 years) with diabetes had a greater risk of all cancers [adjusted relative risk (RR) 3.42; 95% confidence interval (CI), 1.78-6.57], digestive cancers (adjusted RR 2.88; 95% CI 1.15-6.94) and urinary cancers (adjusted RR 13.4; 95% CI 2.70-66.3) compared with individuals in the same age group without diabetes. CONCLUSIONS: Our results clearly demonstrate that middle-aged individuals of Chinese ethnicity with diabetes have a greater risk of all-cause cancer and specific subtypes of cancer.

The ratio of epicardial to body fat improves the prediction of coronary artery disease beyond calcium and Framingham risk scores.

The association between epicardial fat and coronary artery disease (CAD) might be affected by general adiposity. We aimed to determine whether the percentage of epicardial adipose tissue (%EAT), defined as the mass ratio of epicardial fat to body fat, could improve prediction of asymptomatic CAD. We consecutively enrolled 846 adults who underwent coronary computed tomography angiography as part of a health check-up and assessed their coronary stenosis severity and epicardial fat mass. Body fat mass was measured by bioelectrical impedance analysis. Subjects with CAD history, hyperthyroidism, pitting edema, or subjects taking diuretics or thiazolidinedione were excluded. Obstructive CAD was defined as at least one coronary artery with 50 % or greater obstruction, and severe CAD was defined as 70 % or greater obstruction. The %EAT had the maximum area under the curve for predicting the presence of CAD and superior discriminative performance to EAT and other EAT-indexed parameters. Multivariable logistic regression analysis revealed that %EAT >0.41 % was a predictor of obstructive CAD [odds ratio 3.59 (95 % confidence interval 2.28-5.64)], and %EAT >0.47 % was a predictor of severe CAD [4.01 (2.01-7.99)] after adjustment for calcium score and Framingham risk score. This prediction was more pronounced in subjects with higher body fat percentage (≥25 % for men and ≥35 % for women), Framingham risk score (≥10 %), or calcium score (≥100). A spillover of body fat at epicardium over a critical threshold is associated with significant coronary stenosis. This association was independent of obesity, coronary calcium burden, and Framingham risk factors.

Carotid Atherosclerosis Progression and Risk of Cardiovascular Events in a Community in Taiwan.

The authors investigated the association between progression of carotid atherosclerosis and incidence of cardiovascular disease in a community cohort in Taiwan. Data has rarely been reported in Asian populations. Study subjects were 1,398 participants who underwent ultrasound measures of common carotid artery intima-media thickness (IMT) and extracranial carotid artery plaque score at both 1994-1995 and 1999-2000 surveys. Cox proportional hazards model was used to assess the risk of incident cardiovascular disease. During a median follow-up of 13 years (1999-2013), 71 strokes and 68 coronary events occurred. The 5-year individual IMT change was not associated with development of cardiovascular events in unadjusted and adjusted models. Among subjects without plaque in 1994-1995, we observed elevated risk associated with presence of new plaque (plaque score >0 in 1999-2000) in a dose-response manner in unadjusted and age- and sex- adjusted models. The associations attenuated and became statistically non-significant after controlling for cardiovascular risk factors (hazard ratio [95% confidence interval] for plaque score >2 vs. 0: stroke, 1.61 [0.79-3.27], coronary events, 1.13 [0.48-2.69]). This study suggested that carotid plaque formation measured by ultrasound is associated increased risk of developing cardiovascular disease, and cardiovascular risk factors explain the associations to a large extent.

High-fat diet induces cardiomyocyte apoptosis via the inhibition of autophagy.

PURPOSE: Excessive fat intake induces obesity and causes cardiac injury. Intracellular degradation process involving destruction of long-lived proteins and organelles maintains homeostasis for cells under stress. The purpose of this study was to explore the relation of high-fat diet (HFD)-induced cardiac injury and intracellular degradation process with regard to autophagy and ER stress. METHODS AND RESULTS: HFD feeding for 24 weeks induced hyperglycemia, hyperlipidemia, and cardiac hypertrophy in adult male C57BL/6 mice. In the heart, PARP cleavage, an indicator of apoptosis, levels of LC3-II and p62, indicators of autophagy, and CHOP, indicator of ER stress, were increased. A palmitate-treated cardiomyoblast (H9C2) cell culture was examined to explore how HFD induced myocardial injury. Excessive palmitate (400 µM) treatment induced apoptosis and increased the number of autophagosomes and acid vacuoles of H9C2 cells. Besides, it elevated the expression of LC3-II, p62, and PARP cleavage. Induction of autophagy by rapamycin ameliorated palmitate-induced apoptosis, while inhibition of autophagy by 3-methyladenine or LC3 siRNA exacerbated palmitate-induced apoptosis. Palmitate treatment also induced CHOP expression which is associated with ER stress. CONCLUSION: HFD can cause cardiac injury by induction of apoptosis which is associated with autophagy dysregulation and ER stress. In addition, autophagy deficiency augments cardiac apoptosis, suggesting that autophagy serves as a pro-survival role in lipotoxic condition.

Time-dependent cellular response in the liver and heart in a dietary-induced obese mouse model: the potential role of ER stress and autophagy.

PURPOSE: Both endoplasmic reticulum stress (ER stress) and autophagy are essential for the response of the protein quality control system to cellular stresses. This study investigated the influence of the duration of a high-fat diet (HFD) in mice on tissue-specific cellular responses, specifically with regard to the role of autophagy and ER stress. METHODS: Male mice aged 6-7 weeks were fed ad libitum with a standard chow diet or with a HFD for 2, 4, 8, or 16 weeks. RESULTS: The HFD progressively increased mean body weight and induced tissue hypertrophy. The expression of PERK was suppressed in the liver after 16 weeks of the HFD and in the heart after 8 weeks of the HFD. Procaspase 12 and its activated form were induced in the liver with the HFD after 2 weeks, but not in the heart over the 16-week period. The activation of hepatic AMPK was elevated following 4 weeks of the HFD, but was inhibited after 16 weeks of the HFD. The ratio of LC3II to LC3I in the liver did not increase except in those mice fed the HFD for 16 weeks. The expression of AMPK and LC3 in the heart did not change over the entire 16 weeks of feeding the HFD. Cleaved PARP was increased in the liver and heart of mice receiving the HFD for 8 weeks. CONCLUSIONS: This study provides evidence that a HFD affects the cellular protein quality control processes responsible for metabolic disorder in a tissue- and duration-dependent manner.

Total 25-hydroxyvitamin D concentration as a predictor for all-cause death and cardiovascular event risk among ethnic Chinese adults: a cohort study in a Taiwan community.

BACKGROUND: Evidence of an inverse association between serum 25-hydoroxyvitamin D [25(OH)D] and the risk of all-cause death and cardiovascular disease from prospective studies is inconsistent. We tested the relationship between 25(OH)D and the risk among adult ethnic Chinese in Taiwan. METHODS: We conducted a community-based cohort study of 1816 participants (age 60.2±10.2 yrs, 45.0% women) in the Chin-Shan Community Cardiovascular Cohort Study who were free of cardiovascular diseases at baseline and provided 25(OH)D measurements. RESULTS: During a median 9.6 (interquartile range, 8.8- 10.5) years' follow-up period, totally 263 cases developed cardiovascular death events and 559 participants were documented to death from any cause. As 25(OH)D concentration increased, the incidence rates of cardiovascular events and all-cause death decreased progressively. 25(OH)D was inversely associated with all-cause death: the adjusted hazard ratio was 0.49 (95% confidence interval [CI], 0.25-0.97) for the third quartile and a significant J-shape relationship was found. The performance measures by integrated discriminative improvement showed significant improvement after adding 25(OH)D information (0.14%, 95% CI, 0.03-0.31, P=0.050, for all-cause death and 0.32%, 95% CI, 0.02-0.62, P=0.018 for cardiovascular events). CONCLUSION: These findings suggested a modest inverse association between 25(OH)D and the risk of all-cause death among diabetic participants and a good predictive factor in the community. Further studies to investigate the mechanism of vitamin D role on health effect are warranted.

Urinary biomarkers of oxidative and nitrosative stress and the risk for incident stroke: a nested case-control study from a community-based cohort.

BACKGROUND: Oxidative and nitrosative stress has suggested to be involved in the pathophysiology of cardiovascular diseases, but has unclear relationship with the risk for incident stroke. METHODS: In this nested case-control study, cases consisted of 131 participants who were free of stroke at screening and experienced incident stroke during the follow-up period. Controls were 1:1 frequency-matched for age and sex. Baseline levels of urinary creatinine-indexed biomarkers were measured using liquid chromatography-tandem mass spectrometry, including 8-iso-prostaglandin F2α (8-iso-PGF2α), 4-hydroxynonenal conjugate with mercapturic acid, 8-hydroxydeoxyguanosine and 8-nitroguanine. RESULTS: The levels of urinary 8-iso-PGF2α in stroke cases were higher than in controls [median (interquartile range), 1.13 (2.23-4.36) µg/g creatinine versus 0.71 (1.34-3.02) µg/g creatinine, p=0.004]. After adjusting cardiovascular risk factors, the association remained that higher level of urinary 8-iso-PGF2α entailed the greater risk for incident stroke [per 1 standard deviation increase in log-transformed value, adjusted odds ratio, 1.40; 95% confidence interval (CI), 1.06-1.85; p=0.005] with a significant increasing trend across its quartiles (p for trend=0.016). After adding urinary 8-iso-PGF2α, the prediction model not only improved discrimination between participants with or without incident stroke (integrated discrimination improvement, 0.025; 95% CI, 0.006-0.045; p=0.005), but enhanced stroke risk stratification (net reclassification improvement, 19.8%; 95% CI, 4.6-35.1%; p=0.011). In contrast, the relationships were non-significant among the other three biomarkers. CONCLUSIONS: Our findings demonstrated that urinary 8-iso-PGF2α could be an independent biomarker of oxidative stress for prediction of the risk for incident stroke.

N-3 polyunsaturated fatty acids decrease levels of doxorubicin-induced reactive oxygen species in cardiomyocytes -- involvement of uncoupling protein UCP2.

BACKGROUND: Use of the chemotherapeutic drug doxorubicin (DOX) is associated with serious cardiotoxicity, as it increases levels of reactive oxygen species (ROS). N-3 polyunsaturated fatty acid dietary supplements can be of benefit to patients undergoing cancer therapy. The aims of this study were to determine whether DOX-induced cardiotoxicity is related to mitochondrial uncoupling proteins and whether eicosapentaenoic acid (EPA, C20:5 n-3) or docosahexaenoic acid (DHA, C22:6 n-3) affects DOX-induced cardiomyocyte toxicity. RESULTS: Treatment of H9C2 cells with DOX resulted in decreased cell viability and UCP2 expression. Treatment with 100 µM EPA or 50 µM DHA for 24 h resulted in a maximal mitochondria concentration of these fatty acids and increased UCP2 expression. Pretreatment with 100 µM EPA or 50 µM DHA prevented the DOX-induced decrease in UCP2 mRNA and protein levels, but these effects were not seen with EPA or DHA and DOX cotreatment. In addition, the DOX-induced increase in ROS production and subsequent mitochondrial membrane potential change (∆ψ) were significantly attenuated by pretreatment with EPA or DHA. CONCLUSION: EPA or DHA pre-treatment inhibits the DOX-induced decrease in UCP2 expression, increase in ROS production, and subsequent mitochondrial membrane potential change that contribute to the cardiotoxicity of DOX.

The reduced autophagic response by oxidative stress in angiotensin II-induced hypertrophic H9C2 cells causes more apoptotic cell death.

Autophagy is an important process in the pathogenesis of cardiovascular diseases, and angiotensin II (Ang II) plays a causative role in the induction of cardiomyocyte autophagy. The purpose of this study was to explore whether, under conditions of oxidative stress, levels and types of cell death were different in untreated and Ang II-treated cardiomyocytes (H9C2 cells). Treatment with 20 µM Ang II induced cardiac hypertrophy in H9C2 cells, with increased expression of the hypertrophic markers c-Fos, ß-myosin heavy chain, atrial natriuretic factor (ANF), and brain natriuretic factor (BNF). Under normal conditions, there was no difference in the levels of autophagic vacuoles and apoptotic bodies in untreated and Ang II-treated H9C2 cells. However, oxidative stress generated by 100 µM H2O2 triggered autophagy in untreated control cells, but had a reduced effect in Ang II-induced hypertrophic cells, resulting in more cell death, and this was associated with a decrease in connexin 43 expression. Blocking this autophagic response with 3-methyladenine resulted in a significant increase in cell death and apoptosis of H9C2 cells but did not significantly affect the response of Ang II-treated cells. The autophagic response to 100 µM H2O2 provides a survival advantage for cells and this is reduced by Ang II treatment.

Eicosapentaenoic acid attenuated oxidative stress-induced cardiomyoblast apoptosis by activating adaptive autophagy.

PURPOSE: Recently, several large, randomized clinical trials have proven the benefits of eicosapentaenoic acid (EPA) in cardiovascular prevention. However, the precise protective mechanisms of EPA for heart disease are still controversial. In this study, we evaluate the possible protective effects of EPA, especially the role of autophagy, against cardiomyocyte apoptosis induced by oxidative stress. METHODS: H9C2 myocardioblasts were incubated with 80 µM EPA for 24 h and then exposed to 400 µM of hydrogen peroxide for 3 h. Autophagic response, lysosome function, and apoptosis were analyzed at the end of the experiment. RESULTS: Preincubation of EPA significantly inhibited apoptosis and increased cell viability for H9C2 cells under oxidative stress. The effects of EPA on apoptosis and cell viability were suppressed by 3-MA treatment (autophagic inhibitor). Oxidative stress decreased Beclin 1 protein expression, increased the ratio of LC3II/LC3I, and reduced the formation of acid organelles, whereas the preincubation of EPA abrogated the negative effect of oxidative stress on H9C2 by mediating the autophagic response. Inhibiting autophagy by 3-methyladenine reversed the EPA effect significantly by increasing the ratio of LC3II-LC3I. Treatment with 3-MA did not alter the increment of acid organelles by EPA preincubation. In addition, EPA restored the phosphorylation of Akt activated by H2O2 treatment and induced the phosphorylation of AMPK in H9C2 cells under oxidative stress. CONCLUSION: EPA attenuated oxidative stress-induced cardiomyocyte apoptosis by activating an adaptive autophagic response.

Comparison of predictive performance of various fatty acids for the risk of cardiovascular disease events and all-cause deaths in a community-based cohort.

BACKGROUND: The issue of whether saturated fats and trans fats are superior predictors of all-cause death and cardiovascular disease than n-3 polyunsaturated fatty acids, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), remains a matter of contention. Furthermore, few studies have examined the relationship between fatty acids and the outcomes of cardiovascular disease (CVD) in Asian populations. The aim of this study was to compare the effectiveness of various plasma fatty acids as predictors for all-cause death and CVD events in an ethnic Chinese population. METHODS: This study assembled a community-based prospective cohort, comprising 1833 participants (60.6 ± 10.5 yrs, 44.5% women) who underwent a comprehensive evaluation of fatty acids in blood using gas chromatography. None of the subjects had a history of CVD at the time of recruitment. RESULTS: A total of 568 individuals died and 275 individuals developed CVD during the follow-up period (median of 9.6 years; interquartile range of 8.9-10.5 years). Following adjustment for established cardiovascular risk factors, the relative risk of all-cause death in the highest quartile, compared with the lowest quartile, was 1.33 for saturated fats (95% confidence interval [CI], 1.01-1.75, test for trend, P = 0.015), 1.71 for trans fats (95% CI, 1.27-2.31, test for trend, P = 0.0003), 0.77 for EPA (95% CI, 0.59-1.00, test for trend, P = 0.048), and 0.89 for DHA (95% CI, 0.68-1.18, test for trend, P = 0.354). Similar patterns were observed for CVD events. Trans fats presented the largest area under the receiver operator characteristic curve (0.740, 95% CI, 0.716-0.766) for the prediction of all-cause death. A mutually adjusted two-marker model indicated that saturated fats and trans fats were significant predictors of all-cause death and CVD; however, the other fatty acids were not. In addition, trans fats presented the greatest improvement in net reclassification for all-cause death (7.7%, P = 0.003), followed by EPA (3.8%, P = 0.033). Saturated fats presented the greatest improvement in net reclassification for CVD events (5.6%, P = 0.039). CONCLUSIONS: Our data provides strong evidence to support that plasma saturated fats and trans fats can predict all-cause death and CVD more effectively than other fatty acid markers.