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Previous evidence suggests a potential dual impact of aging and vitamin B6 (B6) deficiency on polyunsaturated fatty acid (PUFA) metabolism; gender may influence PUFA biosynthesis. Perturbation of PUFA compositions during B6 deficiency could be linked to age-related health outcomes. However, little is known about the interrelationships between vitamin B6, PUFA, and gender in the older population. Therefore, we investigated whether gender-specific associations of B6 intake and plasma pyridoxal 5’-phosphate (PLP) concentration, respectively, with plasma PUFA concentrations and ratios (eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), arachidonic acid (AA), EPA + DHA, EPA/AA, and (EPA + DHA)/AA) existed in older adults. We further examined the relationships of adequate B6 status (PLP ≥ 20 nmol/L) with high (above median) plasma PUFA relative to deficient B6 status. This cross-sectional study analyzed 461 participants aged ≥60 years from NHANES 2003–2004. Nutrient intakes were assessed using two 24-h recalls and supplement questionnaires. PLP and PUFA concentrations were measured. Multivariate linear regression assessed the association of B6 intake and PLP with PUFA; multivariate logistic regression evaluated the relationship of adequate B6 status with high plasma PUFA, adjusting for demographic, socioeconomic, and dietary factors; physical activity; smoking; alcohol; medication; and BMI. There were interactions between gender and B6 intake on EPA (P-interaction = 0.008) and AA (P-interaction = 0.004) only, whereas no interaction existed between gender and PLP on PUFA. PLP was directly associated with EPA (β = 0.181, P = 0.002), DHA (β = 0.109, P = 0.005), EPA + DHA (β = 0.14, P = 0.002), EPA/AA (β = 0.186, P = 0.004), and (EPA + DHA)/AA (β = 0.13, P = 0.026). The odds of having high plasma EPA (adjusted (a) OR: 2.03, P = 0.049) and EPA/AA (aOR: 3.83, P < 0.0001) were greater in those with adequate B6 status compared to those with deficient B6 status. In conclusion, in US older adults, a higher PLP level was associated with a greater level of EPA, DHA, EPA + DHA, EPA/AA, and (EPA + DHA)/AA. Adequate B6 status was associated with high EPA and EPA/AA status. These findings suggest that sufficient vitamin B6 status may positively influence PUFA metabolism in older adults.

OBJECTIVES: Polyunsaturated fatty acids (PUFA) such as n-3 PUFA, eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and n-6 PUFA, arachidonic acid (AA) may mediate inflammatory responses. Vitamin B6 deficiency has been shown to alter plasma PUFA levels. This perturbation of PUFA metabolism in vitamin B6 deficiency measured by pyridoxal-5’-phosphate (PLP) may contribute to inflammation. Thus, we aimed to examine the associations of 1) dietary EPA + DHA, and vitamin B6 with plasma ratio of AA/(EPA + DHA) by PLP level, 2) plasma AA/(EPA + DHA) and PLP with C-reactive protein (CRP), a marker for inflammation, and 3) dietary EPA + DHA, and vitamin B6 with CRP level, using NHANES. METHODS: NHANES datasets (2003–2004) with subjects ≥20 years were analyzed, accounting for survey design and sample weights (n = 4486). The significance level was P < 0.05. Covariates were age, gender, ethnicity, BMI, smoking, alcohol, total energy, dietary supplements, physical activity, and NSAIDs, depending on analyses. Multiple linear regression assessed the association of dietary EPA + DHA, and vitamin B6 with plasma ratio of AA/(EPA + DHA) by PLP level (Low: 3 mg/L); then, dietary EPA + DHA, and B6 with CRP level. RESULTS: In the low PLP level, dietary EPA + DHA was negatively associated with plasma ratio of AA/(EPA + DHA) (B = ─5.29, SE = 0.84, P = < .0001), but B6 intake was not, whereas, in the high PLP level, both dietary EPA + DHA (B = ─2.99, SE = 0.53, P = < .0001) and dietary vitamin B6 (B = ─0.21, SE = 0.04, P = 0.0001) were inversely associated with plasma AA/(EPA + DHA). Further, low PLP level was associated with greater odds of moderate to high CRP level compared to high PLP level (adjusted OR (aOR): 2.8, 95% CI: 1.93–4.04, P = < .0001), but plasma AA/(EPA + DHA) was not. In addition, both dietary EPA + DHA (aOR: 0.5, 95% CI: 0.23–0.98, P = 0.04) and vitamin B6 (aOR: 0.8, 95% CI: 0.68–0.95, P = 0.009) were inversely associated with moderate to high CRP level. CONCLUSIONS: Our findings show that low plasma PLP level and low vitamin B6 intake are associated with inflammation, and the relationship may be through their effect on PUFA metabolism, suggesting that increased intake of vitamin B6 and EPA and DHA may protect against inflammation. FUNDING SOURCES: N/A.

Autophagy is a conserved mechanism that plays a housekeeping role by eliminating protein aggregates and damaged organelles. Recent studies have demonstrated that acute ethanol intoxication induces hepatic autophagy in mice. The effect of dietary zinc intake on hepatic autophagic flux during ethanol intoxication has not been evaluated using animal models. Herein, we investigated whether zinc deficiency and excess can affect autophagic flux in the liver in mice and in human hepatoma cells acutely exposed to ethanol. A mouse model of binge ethanol feeding was utilized to analyze the effect of low, adequate, and high zinc intake on hepatic autophagic flux during ethanol intoxication. Autophagic flux was inferred by analyzing LC3II/LC3I ratio, protein levels of p62/SQSTM1, Beclin1 and Atg7, and phosphorylation of 4EBP1. In addition, the degradation of the fusion protein LC3-GFP and the formation of autophagosomes and autolysosomes were evaluated in cells. Ethanol treatment stimulated autophagy in mice and cells. High zinc intake resulted in enhanced autophagy in mice exposed to ethanol. Conversely, zinc deficiency was consistently associated with impaired ethanol-induced autophagy in mice and cells. Zinc-deficient mice exhibited a high degree of ethanol-driven steatosis. Furthermore, zinc depletion increased apoptosis in cells exposed to ethanol. The results of this study suggest that adequate zinc intake is necessary for proper stimulation of autophagy by ethanol. Poor zinc status is commonly found among alcoholics and could likely contribute to faulty autophagy.

OBJECTIVES: Type 2 diabetes (T2D) is a complex and chronic metabolic disorder that involves complex interaction between environmental factors and genetic predisposition. TCF7L2 gene recently emerged as top candidate gene for T2D. Our study is aimed to assess six TCTL2 common polymorphisms: rs7903146, rs12255372, rs11196205, rs7901695, rs7895340 and rs4506565, in relation to T2D and related phenotypes in Cuban Americans who lived in Miami-Dade county, Florida. METHODS: We conducted a case-control study with 341 Cuban Americans (172 without T2D/169 with T2D). Unconditional logistic regression method was used to assess the association between six TCF7L2 SNPs and the risk of T2D in the additive genetic model, and further adjusted by potential confounding factors such as age, sex, BMI, physical activities and calorie intake. Student's t-tests on continuous values of T2D related quantitative traits were compared between risk allele carriers and non-carriers in control subjects. In addition, linkage disequilibrium and haplotype analysis were performed using Haploview 4.2. RESULTS: Four TCF7L2 SNPs (rs7901695, rs4506565, rs7903146 and rs11225537) were significantly associated with the risk of T2D in a Cuban American population after multivariable adjustment. Among non-diabetic control subjects, risk minor allele carriers of three TCF7L2 SNPs (rs7901695 (T > C), rs4506565 (A > T) and rs7903146 (C > T)) had significantly higher fasting glucose level and marginally higher level of glycated hemoglobin (A1C), compared to non-risk allele carriers. Consistently, results from haplotype analysis showed that two haplotypes TAC and CTT, formed by aforementioned three TCF7L2 SNPs (rs7901695, rs450565 and rs7903146), were significantly associated with the risk of T2D (P = 0.0094, and P = 0.0044, respectively), with the frequency of TAC significantly lower and CTT significantly higher in subjects with T2D, compared to subjects without T2D. CONCLUSIONS: The results of this study provide convincing evidence that variation in TCF7L2 genes confers strong susceptibility to T2D in the population studied. FUNDING SOURCES: Funding for this research was provided through an NIH/NIDDK sponsored grant. SUPPORTING TABLES, IMAGES AND/OR GRAPHS

OBJECTIVES: Previous evidence suggests that vitamin B6 deficiency may have a deleterious impact on aging and the metabolism of polyunsaturated fatty acids (PUFA). However, the relationship of aging with vitamin B6 status and PUFA metabolism is poorly understood; population-based studies to assess the relationship between plasma pyridoxal 5′-phosphate (PLP; an active form of vitamin B6) and PUFA status for older adults are lacking. Thus, we examined the associations between plasma PLP concentration and plasma PUFA concentrations and ratios [eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), arachidonic acid (AA), EPA + DHA, EPA/AA, and (EPA + DHA)/AA] among US older adults. We further investigated the association of adequate (PLP ≥ 20 nmol/L) versus deficient (PLP

Vitamin B6-restricted diets and low plasma pyridoxal 5′-phosphate (PLP) status altered plasma polyunsaturated fatty acids (PUFA) compositions. Evidence suggests the role of gender in the metabolism of vitamin B6 and PUFA. However, no epidemiologic study examined the impact of gender on the relationship between vitamin B6 and PUFA status in adults. Thus, we investigated whether there were gender differences in the association of vitamin B6 intake and plasma PLP concentration with plasma PUFA concentrations and ratios (eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), arachidonic acid (AA), EPA + DHA, EPA/AA, (EPA + DHA)/AA) in US young/middle-aged adults. In total, 864 participants (20–59 years, 484 men, 380 women) from the National Health and Nutrition Examination Survey (NHANES) 2003–2004 were used for this cross-sectional study. Nutrient intakes were estimated from two 24 h recalls and supplement questionnaires, plasma PLP and PUFA were measured. Multivariate linear regression was utilized to obtain unstandardized (b) and standardized (β) coefficients. Covariates included demographic, socioeconomic, dietary variables, physical activity level, cigarette smoking status, alcohol consumption, prescription medication use, and BMI. There were significant interactions between gender and PLP on EPA (P-interaction = 0.004), DHA (P-interaction = 0.020), EPA + DHA (P-interaction = 0.010), EPA/AA (P-interaction = 0.002), (EPA + DHA)/AA (P-interaction = 0.004), whereas no interaction between gender and B6 intake existed. In gender-stratified analyses, in men, PLP was positively associated with EPA (β = 0.138, b = 0.104, p = 0.0004), DHA (β = 0.101, b = 0.058, p = 0.036), EPA + DHA (β = 0.125, b = 0.073, p = 0.005), EPA/AA (β = 0.144, b = 0.099, p = 0.0002), (EPA + DHA)/AA (β = 0.123, b = 0.068, p = 0.005). However, no associations between PLP and PUFA existed in women. In conclusion, gender differences were found in the relationships between plasma PLP and plasma EPA, DHA, EPA + DHA, EPA/AA, and (EPA + DHA)/AA, with significant direct associations in men only among US young/middle-aged adults.

OBJECTIVES: Diabetes related complications include kidney, eye, heart diseases and amputations. Advanced Glycation End Products, (AGEs) are biomarkers of T2D. AGEs are covalent adducts formed from reactions between sugars and proteins or lipids. Vitamin D deficiency, prevalent with T2D, increases oxidative stress and inflammation that promotes the formation of AGEs. This study assessed the effect of 4000 IU vitamin D supplements on AGEs in adults with T2D and vitamin D deficiency/insufficiency. METHODS: We assessed changes in serum AGEs of 41 African Americans and Hispanics with T2D and hypovitaminosis D who were supplemented with 4000 IU of vitamin D3 for 6 months. Total AGEs were assessed using commercially available kits (Biotang Inc/TSZ Elisa, Waltham, MA, USA). RESULTS: The mean age of study participants was 54 ± 8 years. AGEs significantly increased at 3 months compared to baseline (Mean Difference = −13.70 ng/ml, P = 0.007). The mean level of AGEs decreased significantly at 6 months of supplementation (Mean Difference = 9.79 ng/ml, P = 0.020). Additionally, the mean serum levels of AGEs were significantly higher at 3 months compared to 6 months among study participants (Mean Difference = 24.52 ng/ml, P

OBJECTIVES: Advanced Glycation End Products, (AGEs) and their soluble receptor (sRAGE) have been implicated in the development of complications and mortality among individuals with type 2 diabetes (T2D). There is limited information on the relationship between AGEs and sRAGE and risk of cardiovascular diseases (CVD) in minority groups, who have a higher burden of T2D. The relationship between AGEs and sRAGE and CVD risks in adults with T2D and vitamin D insufficiency/deficiency was assessed in a minority population. METHODS: A cross sectional study of Hispanics and African Americans with T2D (n = 64, 41 women and 23 men, mean age = 54 ± 9) recruited from two clinics in Miami Dade. Systolic (SBP) and diastolic blood pressure (DBP), weight and height measurement and serum lipid profile were completed. ELISA kits were used to assess serum levels of AGEs (Biotang Inc/TSZ Elisa, Waltham, MA, USA) and sRAGE (Biotang Inc/TSZ Elisa, Waltham, MA, USA). Multiple linear regression was used to assess association between AGEs, sRAGE and CVD risks. RESULTS: A negative and significant association between AGEs and high-density lipoprotein cholesterol (HDL-C)(B = −0.551, P = 0.029) was found. The relationship between AGEs and HDL-C persisted after adjusting for covariates (P

Copper toxicity causes hepatic damage that can lead to the development of hepatocarcinoma. Similarly, copper deficiency has been reported to increase hepatocyte tumorigenesis. Thus, the objective of this work was to explore the role of copper toxicity and deficiency in the regulation of the tumor suppressor protein p53. Using Northern analysis, Western analysis, immunocytochemistry and the human hepatoma cell line Hep G2, this work showed that elevations in hepatocyte copper consistent with Wilson's disease (5.7-fold increase) induced p53 mRNA and confirmed that copper toxicity is correlated with apoptotic cell death. However, Western analysis and immunocytochemistry showed that post-transcriptional mechanisms are a significant part of the process, with p53 translocation from the cytosol into the nucleus of copper-treated cells. Treatment of Hep G2 cells with increasing concentrations of the copper chelator tetraethylenepentamine (TEPA, 0-50 micromol/L, 48 h) reduced cellular copper and increased mean p53 mRNA abundance by over fourfold with nuclear translocation of the wild-type protein. However, TEPA treatment did not result in a loss of cell viability or appear to induce apoptosis.