bluuebunny/crossref_metadata_2025 huggingface dataset:
New insights into the Mayer Hypothesis derived from a dynamic energy balance model
Authors: Thomas Diana , Starner John , Vaidya Ashwin , Silva Analiza , Heymsfield S B , Allison David B
Published: November 2023

Background

In 1956 Jean Mayer and his colleagues proposed a provocative relationship between energy intake (EI), body weight and physical activity (PA) by examining the intake of over 200 sedentary to highly active individuals in West Bengal, India. The investigators found that high levels of EI were associated with high levels of PA. Surprisingly, sedentary individuals were also associated with high EI, resulting in a hyperbolic shaped curve of EI versus PA referred to as the Mayer curve or Mayer hypothesis. Challenges arising from objectively measuring EI and PA in free living humans have made experimentally testing the Mayer hypothesis difficult.

Methods

A mathematical relationship between EI and PA levels (PAL) was derived from a newly formulated one parameter (α) dynamic energy balance equation. To test the validity of the lower end of the Mayer curve, the relationship between the parameter α and PAL was analyzed in subjects having Class 1, 2, and 3 obesity from the Institute of Medicine doubly‐labeled water (DLW) database (N=133, BMI=34.9±5.6 kg/m2). Similarly, the relationship between EI calculated by summing changed body energy stores with DLW measured energy expenditures versus PAL in elite athletes were applied to test the validity of the higher end of the Mayer curve (N=60, 21.7±2.0).

Results

The steady state formulation from the model yielded the algebraic relationship, EI α×PAL×Weight confirming EI was an increasing function of higher values of PAL as hypothesized on the right side portion of the Mayer curve. The theoretical finding was confirmed in the elite athlete database (EI=39.5PAL+1057.6 kcal/d, R2=0.2). On the other hand, the steady state model did not yield the Mayer curve for lower PAL values unless the parameter, α, was inversely proportional to PAL. The inverse proportionality between α and PAL was nearly statistically significant in Institute of Medicine database.

Conclusions

The Mayer hypothesis is theoretically and experimentally validated in individuals with higher PAL. There is some evidence that certain subpopulations of sedentary individuals may be reflected in the Mayer curve, however, additional data needs to be analyzed to determine which subpopulations follow the Mayer curve and which deviate from the Mayer curve.
BMI and Body Fat Mass Are Differentially Associated with fMRI Food‐cue Reactivity in Individuals with Obesity
Authors: Quarles William R , Kahathuduwa Chanaka Nadeeshan , Davis Tyler , O'Boyle Michael , Binks Martin
Published: November 2023

Background

Body Mass Index (BMI) is commonly used to categorize obesity in fMRI research. However, BMI fails to fully account for variability of body composition among individuals (e.g. body fat mass; BFM). Given that adipose tissue produces several hormones received by the brain to affect ingestive behavior, it is important to understand how BMI and BFM may be differentially associated with food‐cue reactivity in the brain.

Objective

To examine the association between both BMI and BFM with brain functional magnetic resonance imaging (fMRI) food‐cue reactivity (FCR).

Methods

Baseline data of 32 subjects (age 19–65 yrs.; BMI 30–39.9kg/m2) was used from a larger study. BMI was calculated from measured height and weight and BFM was measured using bio‐electrical impedance. During the fMRI scan, subjects were shown 240 images (120 food and 120 objects) in an event‐related paradigm. Using the median BMI and BFM as the cut score, subjects were categorized into 2 groups (high and low), for both BMI and BFM. FMRI analyses were conducted on 3 levels in FSL to compare FCR: high BMI vs. low BMI and high BFM vs. low BFM.

Results

FMRI analysis revealed increased FCR in the high BMI compared to low BMI group in the bi‐lateral insular cortices. Increased FCR was seen in high BFM compared to low BFM group in the bilateral precuneus, left angular gyrus, left supramarginal gyrus, right orbitofrontal cortex, right nucleus accumbens, and the right temporal pole.

Conclusion

FCR was greater in both high BMI and high BFM groups compared with low BMI and low BFM groups. However the brain regions involved were different in each. These differences in FCR between BMI and BFM suggest a lack of concordance among these methods for delineating degree of obesity that may influence interpretation of fMRI FCR data. Given that BFM is more closely aligned physiologically with ingestion, it may be prudent to use BFM, not BMI, in fMRI FCR studies of obesity and ingestive behavior.

Support or Funding Information

Funding: Nestle Health Science.
Daily walnut consumption effects lipid profile and body protein in Korean subjects with metabolic syndrome
Authors: Song Eun‐Kyung , Park Hyunjin , Liu Yanan , Kim Hyun‐Sook
Published: November 2023

The objective of current study was to assess the gender differences on the lipid profiles, apoprotein B, and body composition among the subjects with metabolic syndrome after daily walnut intake (45 g) for 16 weeks. 89 participants (44 men, 40±6.2yr) with metabolic syndrome were screened if they meet at least three metabolic syndrome components out of five diagnosis criteria (i.e., waist circumstance ≥90cm for men and ≥85cm for women, blood pressure 130/85mmHg or higher, HDL‐cholesterol ≤40mg/dL for men and ≤50mg/dL for women, triglyceride level ≥150mg/dL, and fasting blood glucose ≥100mg/dL). Blood lipid profiles (consisting of triglyceride, total cholesterol, HDL‐cholesterol, and LDL‐cholesterol), apoprotein B, fasting blood sugar, anthropometric measurement, bioimpedance analysis, and blood pressure were measured at baseline and week 16. The significance of the differences between baseline and week 16 were analyzed using the paired t‐test or Wilcoxon signed‐rank test, as appropriate (p<0.05). Body protein of male and all subjects at week 16 was significantly higher compared to the baseline (p=0.026, p=0.039, respectively), whereas no significance among female subjects (p=0.876). Male showed significantly increased basal metabolic rate at week 16 (p=0.017), but not significant among female subjects (p=0.581) and all subjects (p=0.12). Waist circumstance among female and all subjects were significantly lower compared to baseline (p=0.036 and 0.026, respectively), and marginally significant among male subjects (p=0.050). LDL‐cholesterol and total cholesterol levels were significantly decreased among male subjects (p=0.011 and 0.003, respectively), whereas those among female subjects were not significantly different (p=0.307, and 0.072, respectively). Triglyceride level was significantly decreased among female subjects compared with baseline (p=0.007) by Wilcoxon test. The positive change of apoprotein B among male and all subjects were significant compared with the baseline (p=0.001 and 0.003, respectively), whereas those among female subjects were not significant (p=0.282). The results suggest that daily walnut consumption for 16 weeks may increase body protein and basal metabolic rate, and decrease the levels of LDL‐cholesterol, cholesterol and apoprotein B among male subjects with metabolic syndrome. Also, daily walnut intake may decrease waist circumstance and triglyceride level among female subjects with metabolic syndrome.

IRB(SMWU‐1508‐BR‐051‐01)

Support or Funding Information

California Walnut Commission
Deficiency of β, β‐Carotene‐9′, 10′‐Oxygenase 2 Links to Systemic Inflammation, Dyslipidemia and Glucose Intolerance
Authors: Wu Lei , Guo Xin , Lyu Yi , Clarke Stephen L. , Lucas Edralin A. , Smith Brenda J. , Wang Weiqun , Medeiros Denis M. , Shen Xinchun , Lin Dingbo
Published: November 2023

Objective

The β,β‐carotene‐9′,10′‐oxygenase2 (BCO2) is a mitochondrial inner membrane protein broadly presented in mammals. It was initially discovered as an enzyme that catalyzes the asymmetric cleavage of carotenoids. Recently we have found that BCO2 knockout (KO) mice are more prone to obesity and diabetes. Therefore, the aim of this study was to investigate the mechanism by which BCO2 regulates lipid and glucose metabolism in human primary hepatocytes in culture and in BCO2 KO mice.

Methods

Human primary hepatocytes, HepG2 cells, and BCO2 knockout mice were used as experimental models. Quantitative real time PCR and Western blot were used for gene expression analysis. Untargeted metabolomics, the tolerance tests of glucose, insulin and pyruvate, and blood metabolic profiling were also performed.

Results

The results showed the declined expression of BCO2 protein in primary hepatocyte cultures exposed to high palmitate and/or glucose challenges. BCO2 protein expression was significantly suppressed in HepG2 cells, compared to the human primary hepatocytes. Over‐expression of human BCO2 attenuated lipid accumulation and intracellular oxidative stress in HepG2 cells. Deficiency of BCO2 caused higher mitochondrial respiratory activities, mitochondrial stress, systemic inflammation, elevation of non‐esterified fatty acids and fasting blood glucose, and glucose intolerance in young adult mice. Moreover, depletion of BCO2 resulted in enhanced de novo lipogenesis and gluconeogenesis, and accumulation of diacylglycerol in the liver tissues. However, the whole body fat content and the uptake of circulating lipids and glucose by muscles and/or white adipose tissues were not changed or even decreased in KO mice.

Conclusions

Collectively, the functional and metabolic data suggested that BCO2 contributes to normal mitochondrial function. Loss of BCO2 leads to mitochondrial dysfunction, oxidative stress, and subsequent metabolic disorders in mice.
Gene Expression Data Analysis of High Fat Diet‐induced Obese Mice Following Treatment with a Putative Weight Loss Botanical Blend
Authors: Lu Jihong , Mastaloudis Angela , Ren Yiping , Bartlett Mark
Published: November 2023

Obesity is prevalent worldwide and is a whole body problem affected by several endocrine and metabolic pathways. Similarly, weight loss is a complex process and may be affected by a several mechanisms. In this study, we set up a high fat diet induced obese mouse model to observe the gene expression changes effected by a botanical blend (BB). Obese mice were fed BB for 12 weeks. RNAs were extracted from adipose tissue and hypothalamus tissue for gene expression detection by use of microarray chips. Gene expression data were analyzed using IPA. We set up 3 groups in the study; normal diet controls (LFD), high fat diet controls (HFD) and a high fat diet treatment group (HFDT). Comparisons were performed between HFD vs LFD and HFT vs HFD. In adipose tissue, IPA function and disease analysis showed most of the biological functions and diseases were inhibited in HFDT as compared to HFD while most of the functions and diseases were activated in HFD as compared to LFD, especially in inflammation and immune related functions. Canonical pathway analysis revealed a reversal in negative effects in the HFDT vs HFD as compared with HFD vs LFD. These BB‐induced positive changes were especially prevalent in the NRF2‐mediated Oxidative Stress Response, mTOR signaling, and cAMP mediated signaling pathways. The predictive upstream regulator INSIG1 (insulin induced gen1) and APOE were up‐regulated in HFDT vs HFD. Moreover, the predictive upstream gene RETNLB was down‐regulated in the BB‐treated group. These gene expression changes may be expected to result in a decrease of the inflammatory response. In brain tissue, IPA function and disease analysis also showed a contrary general profile than that found in adipose tissue. Interestingly, many functions such as cell‐to‐cell signaling and interaction were activated in the brain after treatment. We hypothesize that these gene expression changes brought about by the BB may influence the secondary effects or the regulation of weight loss. This hypotheses needs to be proven in further investigation. In conclusion, a weight loss botanical blend treatment can cause several gene expression changes toward anti‐inflammatory, oxidative stress response, and metabolic pathways in a HFD induced mouse model. The insteresting changes in gene expression were also found in brain tissue.
Daily Walnut Consumption Improves Metabolic Syndrome Status in Korean Adults
Authors: Park Hyunjin , Song Eunkyung , Liu Yanan , Song Yeonju , Hwang Hyojung , Kim Hyun‐Sook
Published: November 2023

The objective of this study was to investigate the effects of daily walnut intake on changes of metabolic syndrome components. It is 38 weeks long cross‐over study with 16 weeks of interventions (45g of walnuts and iso‐caloric white bread) and 6 weeks of wash‐out period in between. 71 Korean adults with metabolic syndrome were randomly assigned one of two sequences: (1) walnut‐control sequence (WCS) and (2) control‐walnut sequence (CWS). At each visit (at 0, 16, 22, and 38 weeks), along with five components of metabolic syndrome (waist circumference, blood pressure, levels of HDL‐C, triglycerides, and fasting blood glucose), the participants' anthropometric and bioimpedance analysis measurement, HbA1c, CRP, serum levels of total cholesterol and LDL‐C were measured. Changes from baseline to each visit were determined by using paired t‐test. The mean age was 39.2 years old and 46.5% (n=33) of the participants were women. 47 subjects out of 71 had three metabolic syndrome components, 20 subjects had four, and four subjects had five at baseline. After 16 weeks of walnut consumption, one subject had no risk factors, four subjects had only one metabolic syndrome component, and 19 subjects had two, thus 24 subjects (33%) were reversed back to normal status from metabolic syndrome after walnut consumption. Additional eight subjects also showed decrease of number of metabolic syndrome components compared to baseline (i.e., five components at baseline to three or four after walnut consumption) even though they were still categorized having metabolic syndrome. For each metabolic syndrome component, fasting blood glucose level was decreased after walnut consumption compared to control bread intake (p=0.0001). Subjects in WCS group particularly showed significantly lower fasting blood glucose and HbA1c levels after walnut consumption compared to control bread intake. Participants in CWS group, however showed increment in basal metabolic rate, fat free mass and body protein and reduction of body mass index and body fat percentages after walnut consumption compared to control bread intake. The results suggest that daily walnut consumption for 16 weeks may improve metabolic syndrome status and affect bioimpedance analysis parameters as well.

IRB: SMWU‐1508‐BR‐051

Support or Funding Information

Grant Funding Source: California Walnut Commission
Antidiabetic Effects of Water Extract and Fraction of Mori cortex
Authors: Kim Kyoung Kon , Choe Myeon
Published: November 2023

Previous studies have shown that treatment with Mori cortex extract (MCE) produces antidiabetic effects due to α‐glucosidase inhibition. In this study, we examined the Water Extract and Fraction these antidiabetic effects by glucose uptake, GK activity, PDH activity in HepG2 cells cultured with MCE.

The present study verified the antidiabetic effects of water extract and fraction of Mori cortex and confirmed glucose uptake, glucokinase (GK) activity, and pyruvate dehydrogenase (PDH) activity within the concentration range that does not exhibit cytotoxicity. The experimental results confirmed that no toxicity was shown up to the concentration of 1 mg/mL and glucose uptake was increased up to 125.6 %. It was also confirmed that GK activity was 96.6 % and PDH activity was increased to 123.3 %. As for fractions, it was confirmed that glucose uptake and GK, PDH activity was shown in fraction number 3.
Effect of carbohydrate plus branched‐chain amino acids supplementation on hormonal and inflammatory responses during normobaric hypoxic exercise
Authors: Yang Yan‐Ting , Chen Ching‐Han , Wu Chia‐Ying , Chen Chung‐Yu , Chou Chun‐Chung , Bernard Jeffrey R. , Liao Yi‐Hung
Published: November 2023

Purpose

Provision of carbohydrate (CHO) and branched‐chain amino acids (BCAA) have been both reported to enhance exercise performance and endurance. However, it is still little known whether the combination of CHO and BCAA on the hormonal and immune cell responses to prolonged exercise under hypoxic environment. Therefore, the purpose of this study was to investigate the effects of CHO plus BCAA supplementation on hormonal changes and immune cell responses during exercise under normobaric hypoxic condition.

Methods

Using a double‐blind and crossover design, 8 healthy males (22.0 ± 0.5 yr, VO2max = 50.0 ± 1.8 ml·kg–1·min–1, maximal power [Wmax] = 248.0 ± 5.4) were assigned to two trials in randomized orders, including carbohydrate (CHO) and carbohydrate plus BCAA (CHO/BCAA). Participants rested in hypoxic chamber (13.5% O2) for 30 minutes, and then conducted a 50 min moderate‐intensity cycling exercise (5 min warm‐up, 65% Wmax) in the chamber. Heart rate (HR) and oxyhemoglobin saturation (SpO2) were measured every 10 min during exercise. Venous blood samples were collected at baseline, 30 min rest under hypoxia, every 15 min during exercise, and immediately after exercise for the measurements of blood leukocyte subpopulations, blood glucose/lactate, insulin, and cortisol. The two‐way ANOVA with repeated measure was used to compare the differences for all measurements.

Results

HR and rating of perceived exertion (RPE) began to show a significant increase at 15 min of exercise until the end, and SpO2 started to decrease at 30 min of exercise until the end. However, there were no differences between CHO and CHO/BCAA trails. The blood glucose concentrations did not differ between trails throughout the exercise period. When exercising under hypoxic condition, the blood lactate showed significant increase at 15 min after exercise until the end of exercise (rest: 0.98 mM; end of Ex: 7.6–7.8 mM; p<0.05), but no difference existed between trails. Cortisol but not insulin had significantly increase immediately after exercise (p<0.05), whereas no significant differences were observed on these two hormones during exercise between two trials. Among leukocyte subpopulations, only total white blood cells counts showed significantly increase at 15 min after exercise, whereas no significant differences in these hematological parameters (i.e. white blood cell, neutrophils, lymphocyte, and monocyte) during exercise between these two trials.

Conclusions

This investigation demonstrates that despite increases in HR, RPE, cortisol, and white blood cells when providing CHO during prolonged exercise under normobaric hypoxia, these parameters were not affected by addition of BCAA to CHO. Thus, these results suggest that the supplementation consisting of CHO and BCAA has no effect on further changing inflammatory response when exercising under hypoxia.
L‐carnitine supplement and running training improve skeletal muscle recovery after hindlimb suspension induced muscle atrophy
Authors: Lim Kiwon , Jang Jiwoong
Published: November 2023

Several studies demonstrated that endurance exercise has an effect on protein synthesis through the activation of Akt1/mTOR pathway. Along with Akt1/mTOR pathway, PGC‐1α effects on protein synthesis through the inhibition of muscle specific E3 ligases expression such as atrogin‐1 and MuRF1. PGC‐1α expression in skeletal muscle can be induced by a stimulus of endurance exercise. Recently, L‐carnitine down‐regulates atrogin‐1 and MuRF1 mRNA expression and reduces muscle wasting in a rat model of cancer cachexia. Also, L‐carnitine supplement can increase the level of IGF‐1, which in turn activates the downstream Akt1/mTOR signaling pathway. Altogether, these findings suggest that L –carnitine and combined with running exercise could promote muscle recovery after disuse induced muscle atrophy through the inhibition of E3 ligases expression and Akt1/mTOR pathway activation. However, the effect of LC supplement in growing rats on muscle atrophy and recovery of muscle mass combined with running exercise after muscle atrophy induced by disuse has not yet been reported. Therefore, the purpose of this study was to clarify whether L‐carnitine supplement and combined with running exercise improve muscle mass recovery after disuse induced muscle atrophy through the inhibition of UPP and activation of Ak1/mTOR pathway. Male Wistar rats were randomly assigned to 4 groups; sedentary after hindlimb suspension with 1,250 mg/kg casein supplement group (Sed‐Con), sedentary after hindlimb suspension with 1,250 mg/kg l‐carnitine supplement group (Sed‐Car), running exercise after hindlimb suspension with 1,250 mg/kg casein supplement group(Ex‐Con), and running exercise after hindlimb suspension with 1,250 mg/kg l‐carnitine supplement group (Ex‐Car) for 4wk. Soleus muscle significantly greater in exercised groups compared to sedentary groups. MuRF1 mRNA expression is significantly decreased by L‐carnitine supplement in sedentary and exercise groups. PGC‐1α and Akt1 mRNAs expression in muscle is significantly increased by the exercise and L‐carnitine supplement. However, PGC‐1α protein expression is significantly increased in Ex‐Car group compared to Sed‐Con group. mTOR mRNA expression is only increased in Ex‐Car group groups compared to the Sed‐Con group. In conclusion, the main findings of this study is that L‐carnitine combined running exercise enhanced the muscle recovery after hindlimb suspension induced muscle atrophy in soleus muscle possibly through of the increased expression of PGC‐1α by inhibiting the muscle specific E3 ligases expression and activation of Akt1/mTOR pathway. These results provide important information that understanding of the mechanisms underlying muscle recovery after hindlimb suspension induced muscle atrophy by the L‐carnitine combined with running exercise.
Lactate co‐ingested with caffeine stimulates fat oxidation in resting mice
Authors: Yoo ChoongSung , Kim Jisu , Kim Heejae , Hwang Yoonyoung , Kim Eunseok , Park Yeram , Lim Kiwon
Published: November 2023

Lactate is traditionally seen as a fatigue substance. However, there are many beneficial sides of lactate demonstrated in the last decades. Nevertheless, it was not known whether lactate changes on energy metabolism and energy substrates utilization. Accordingly, we investigated the effects of lactate treatment by using an open circuit calorimetry system on resting energy expenditure in resting mice for the duration of 24h. Thirty‐two Sprague Dawley male rats of 7 wk divided into control (Con; DW ingestion), caffeine (Caf; 1mg/100g), lactate (Lac; 400mg/100g), and caffeine and lactate mixed compound (Caf+Lac; 1mg, 400mg/100g) groups. The rats were given the substances to each group by oral administration (Experiment 1). We examined 6 hours on energy metabolism in resting by using respiratory metabolic chambers. There was no significant difference in O2 uptake and CO2 production between groups for 6 hr. However, Lac and Caf+Lac ingestions were significantly less than Con in respiratory exchange ratio (RER) over 2 hr after administration. Therefore, in fat oxidation, Lac and Caf+Lac groups were significantly higher than Con group over 2 hours after administration but not change in carbohydrate oxidation. These results suggest that the caffeine and lactate mixed compound and lactate alone groups can improve fat oxidation over 2 hr. Moreover, we performed additional experiment to clarify the mechanism; a time‐based comparison of the effects of caffeine/lactate mixed compound (Experiment 2). We determined the effect of Caf+Lac (1mg, 400mg/100g) based on time. Twenty‐four male SD rats of 7 wk were divided into 4 groups; 0 min, 30 min, 60 min and 120 min after ingestion. We determined MCT1, MCT4, GLUT4, FAT/CD36, CPT1b and PGC‐1α mRNAs in soleus muscle by RT‐PCR. MCT4 mRNA was significantly higher in 30 min and 60 min than in 120 min. GLUT4 mRNA in 120 min was lower than in the other groups. Also, in PGC‐1α in 120 min was significantly higher than in 30 min and 60 min. These proteins could promote fat oxidation by the caffeine and lactate mixed compound.
Vitamin B‐6 is Negatively Associated with Oxidative Stress Independently of Homocysteine in Hemodialysis Patients
Authors: Yeh En‐Ling , Huang Yi‐Chia , Chen Cheng‐Hsu
Published: November 2023

Hemodialysis treatment may increase the excretion of vitamin B‐6 (pyridoxal 5′‐phosphate, PLP). Decreased PLP concentration has been shown to be associated with increased levels of homocysteine and oxidative stress. However, very few studies on the association of PLP concentration with homocysteine concentration and oxidative stress status at pre‐ and post‐hemodialysis have been reported. The purpose of this study was to determine the associations among PLP, homocysteine and oxidative stress indicator (malondialdehyde, MDA) in hemodialysis patients. A cross‐sectional design was carried out. 66 patients who had received hemodialysis treatment for 4 hours three times per week were recruited. Anthropometric data and biochemical measurements were collected or analyzed at pre‐ and post‐hemodialysis session. The pre‐hemodialysis levels of plasma PLP and homocysteine were significantly decreased after the completion of hemodialysis; while MDA level maintained stable before and after the hemodialysis. The pre‐hemodialysis plasma MDA level was negatively correlated with post‐hemodialysis plasma PLP after adjusting for age, sex, Kt/V, homocysteine values and diabetes. No association of MDA with plasma homocysteine level at pre‐ or post‐hemodialysis. Vitamin B‐6 is negatively associated with oxidative stress independently of homocysteine in hemodialysis patients.

Support or Funding Information

This study was partially supported by Taichung Veterans General Hospital, Chiayi Branch (RVHCY105001), Taiwan.
The Effects of Vitamin D Supplementation on Glucolipid Metabolism and Pancreas and Muscle Histological Characteristic in Diabetic Rats
Authors: Wang Qiuzhen , Ma Aiguo , Chi Jinghua , Dou Xiaojuan , Liu Yufeng , Zhao Yanxu
Published: November 2023

In recent years, the effect of vitamin D (VD) on DM has attracted more and more attention. The aim of this study was to investigate the influence of VD3 supplementation on glucolipid metabolism and the pathological characteristic of pancreas and muscles in DM. We established diabetic rat model by intraperitoneally injection streptozocin based on high‐fat diet. The rats were randomly divided into 6 groups and supplemented with different doses of VD (normal control, diabetes model; 180, 900, 4500 and 7200 IU/kg IU/kg VD supplementation groups, respectively). Glucolipid metabolism and liver function were measured by automatic biochemical analyzer. HE staining was used to detect the histological feature in pancreas and muscles. The results showed that HDL‐C in the VD supplementation groups were higher than N group (P<0.05), while there are no differences in TC and LDL‐C. Liver function test showed that ALT in 900 IU/kg VD group were reduced significantly. Pancreas and muscle biopsy showed that the supplement of VD could significantly improve the morphology of islet cell and muscle and make them close to normal. In conclusion, VD supplementation may ameliorate the histological damage in pancreas and muscle in DM, and the glucolipid metabolism could be improved to certain extent.

Support or Funding Information

Supported by NSFC‐81472983
Parathyroid Hormone in Relation to Various Vitamin D Metabolites in Adult Females
Authors: Al‐Daghri Nasser , Yakout Sobhy , Al‐Saleh Yousef , Aljohani Naji , Al‐Attas Omar , Alokail Majed
Published: November 2023

Background

Vitamin D binding protein (DBP) and albumin are the important determinants of circulatory 25(OH)D in adults. Physiological function of vitamin D is particularly regulated by vitamin D binding proteins. Serum parathyroid hormone (PTH) is considered as the biological activity reader of circulating 25(OH)D. We therefore examined the relationships between serum total, free and bioavailable 25(OH)D versus PTH in apparently healthy Saudi female adults.

Methods

A total of 350 apparently healthy Saudi female adults [(Mean ± standard deviation) Age (years) 52.9±9.2; Body Mass Index (kg/m2) 32.9±5.4)] were included in this observational study. Anthropometrics was measured as well as fasting glucose, lipid profile, calcium and phosphorous using routine methods. Serum 25(OH)D was measured using an electrochemiluminescence immunoassay. Serum DBP was determined by ELISA. Free and bioavailable 25(OH)D were calculated by comparing concentrations of total 25(OH)D, DBP, and albumin.

Results

Data revealed that circulating total 25(OH)D had weak but significant inverse association with DBP (R=−0.24; p<0.01), and strong inverse associations with free 25(OH)D (R=−0.87; p<0.001), albumin bound 25(OH)D (R=−0.88; p<0.001) and bioavailable 25(OH)D (R=−0.89; p<0.001). None of the vitamin D metabolites, including 25(OH)D, correlated with serum PTH.

Conclusion

Various metabolites of 25(OH)D are not correlated with serum PTH in Saudi adult females. Bioavailable, albumin‐bound and free 25(OH)D cannot be surrogate measures for vitamin D status, at least in this population.

Support or Funding Information

The study was funded by the Prince Mutaib Chair for Biomarkers of Osteoporosis, Deanship of Research Chairs in King Saud University
Selenium‐dependent Resolution of Inflammation in Macrophages is mediated through Δ12PGJ2‐CRTH2 Signaling Axis
Authors: Bastihalli‐Tukaramrao Diwakar , Nettleford Shaneice , Prabhu K. Sandeep
Published: November 2023

Selenium in the form of selenoproteins is known to mitigate inflammation by differential regulation of cyclooxygenase (COX)‐derived prostaglandin (PG) synthesis in endotoxin lipopolysaccharide (LPS)‐treated macrophages as well as in other models of inflammation. During late phase of inflammation, MΦs supplemented with selenium produce elevated levels of pro‐resolution cyclopentenone prostaglandins (CyPGs), such as Δ12‐PGJ2 that downregulate inflammatory signalling pathways. MΦs express the chemoattractant receptor‐homologous molecule, a cell surface receptor, expressed on Th2 cells (CRTH2/DP2) that exhibits high affinity for Δ12‐PGJ2. In this study, we investigated the role of CRTH2 signalling during LPS‐induced inflammation in murine macrophages cultured in the presence or absence of selenium. Deletion of Crth2 in MΦs, using the CRISPR/ Cas9 system, resulted in significant increase in the expression of genes required for PG biosynthesis (COX‐2 and microsomal PGE2 synthase‐1) and pro‐inflammatory mediator such as iNOS, mimicking the effects seen in selenium deficiency. Furthermore, use of specific pharmacological antagonists of CRTH2, inhibition of heterotrimeric G protein downstream of receptor using pertussis toxin, or use of specific inhibitors of enzymes leading to the biosynthesis of Δ12‐PGJ2 all increased expression of proinflammatory genes, indicating a previously underappreciated feedback mechanism of autocrine/paracrine role of Δ12‐PGJ2‐mediated CRTH2 signalling in selenium‐dependent resolution of inflammation.

Support or Funding Information

Funded by NIH R01 DK077152 to KSP
Mechanistic Aspects of Selenium Delivery by Selenoprotein P
Authors: Copeland Paul , Shetty Sumangala
Published: November 2023

Selenoprotein P (SELENOP) is a serum glycoprotein that is required for proper selenium distribution in mammals, particularly in supplying selenium to the brain and testes. As the sole mechanism for providing essential selenium to developing spermatazoa, SELENOP metabolism is central to male fertility in all mammals. In addition, this process is important for proper brain function, especially under conditions of limited dietary selenium. Several specific and nonspecific mechanisms for SELENOP uptake in target tissues have been described but the utilization of the protein as a source of selenium for intracellular selenoprotein production has not been systematically characterized. We have examined the process by which SELENOP delivers selenium to cells using a robust selenium uptake assay that measures selenium utilization in cells fed 75Se‐radiolabeled SELENOP. Using a series of inhibitors and modulators we have identified specific requirements and regulators of the process.

Support or Funding Information

This work was supported by the Found Animals Foundation and NIH GM077073
Folic Acid and Riboflavin Deficiencies in Murine Macrophage RAW Cells Reduce LPS‐induced Nitric Oxide Production
Authors: Rittmann Marijke , Miller Joshua W , Gow Andrew
Published: November 2023

Methylenetetrahydrofolate reductase (MTHFR) is a flavin adenine dinucleotide (FAD)‐dependent folate metabolizing enzyme that catalyzes the conversion of dihydrobiopterin to tetrahydrobiopterin (BH4). BH4 is an essential cofactor for nitric oxide synthase (NOS) that produces nitric oxide for multiple functions including vasodilation and blood pressure (BP) regulation. Genome‐wide association studies have linked a common polymorphism, C677T, in MTHFR with BP, and riboflavin supplements have been shown to reduce BP in individuals homozygous for the 677TT variant form of the enzyme. We hypothesize that this relationship between MTHFR, riboflavin, and BP is mediated through nitric oxide synthesis. We investigated this hypothesis in vitro in stimulated murine macrophage RAW cells, which express the inflammatory form of NOS, exposed to standard and reduced levels of folic acid and riboflavin. RAW cells were grown in medium with 0.4 mg/L riboflavin and 4.0 mg/L folic acid (control), 0.04 mg/L riboflavin (lowB2), or 0.4 mg/L folic acid (lowFA) for 48 hours, and then exposed to 100 ng/ml or 1000 ng/ml lipopolysaccharide (LPS) for 24 hours. Media was then analyzed for nitric oxide production by chemiluminescence assay using a Nitric Oxide Analyzer. Quantitative PCR was used to analyze gene expression of inducible NOS (iNOS). In all three media conditions, no differences in RAW cell proliferation rates were observed over 48 hours. After LPS exposure, nitric oxide production in the lowB2 and lowFA cells was 30–35% and 35–40% of the control cells, respectively (p ≤ 0.02). Expression of iNOS after LPS induction increased in all three media conditions. LPS‐induced nitric oxide production is reduced in RAW cells grown in either riboflavin or folic acid deficient media independent of iNOS expression. These results demonstrate the importance of the folate cycle in maintaining NOS function, and indicate a potential mechanism for the effects of MTHFR polymorphisms on BP.

Support or Funding Information

Department of Nutritional Sciences, Rutgers University, New Brunswick, NJ
Modifications to Ascorbate Concentration and pH Result in Faster Deconjugation of Whole Blood Folate Polyglutamates to Monoglutamates for Measurement by Liquid Chromatography‐Tandem Mass Spectrometry
Authors: Stamm Rosemary A , Fazili Zia , Pfeiffer Christine M
Published: November 2023

Objective

Folate in red blood cells is polyglutamylated and requires deconjugation of glutamate residues by the enzyme γ glutamyl hydrolase (GGH) (E.C. 3.4.19.9) during an incubation step prior to analysis. The reported pH optimum for human GGH is 4.5. A lengthy incubation time is required for measurement of whole blood total folate by liquid chromatography‐tandem mass spectrometry (LC‐MS/MS) to ensure all folates are measured as folate monoglutamates. We aimed to reduce the time taken for enzymatic cleavage of folate polyglutamates to monoglutamates.

Methods

We investigated modification of pH and ascorbate concentration to the hemolysate diluent to optimize deconjugation of folate polyglutamates. Preliminary testing was performed on four samples, two with high non‐methyl folate concentrations.

Results

The conventional dilution of whole blood (1/11 in 1% ascorbic acid solution, pH 2.7) resulted in a mean hemolysate pH of 3.8. Dilution with 0.5% ascorbic acid (pH 2.9) resulted in a mean hemolysate pH of 4.2 and dilution with 1% ascorbic acid adjusted to pH 4.1 resulted in a mean hemolysate pH of 4.4. Both conditions resulted in <1% of 5 methyltetrahydrofolate (5‐methylTHF) remaining as dilglutamate after 3 h incubation at 37°C, while ~2% of 5 methylTHF remained as diglutamate after 4 h incubation in conventionally prepared hemolysates. However, both conditions also resulted in a greater loss of tetrahydrofolate (THF) internal standard compared with the conventional dilution, likely resulting in a corresponding greater overestimation of THF concentration. In a follow up experiment, 2% sodium ascorbate solution offered better protection of THF internal standard compared with 1% sodium ascorbate (both adjusted to achieve a hemolysate pH of 4.3). However, 2% sodium ascorbate resulted in inadequate deconjugation with >4% of 5 methylTHF remaining as diglutamate after 4 h incubation, while <1% remained as 5‐methylTHF diglutamate in 1% sodium ascorbate.

Conclusion

The conventional dilution of whole blood results in a pH that is more acidic than the pH optimum of human GGH. Faster and more complete deconjugation of folate polyglutamates can be achieved either by reducing the ascorbic acid concentration or increasing the diluent pH to achieve a hemolysate pH closer to 4.5. Increasing the ascorbate concentration provides additional protection of THF, however, results in slower and less complete deconjugation, thereby resulting in under‐recovery of total folate. An additional means of protecting THF during incubation is required to accurately measure whole blood hemolysate total folate by LC‐MS/MS.
Folic acid intake among U.S. women of childbearing age with suboptimal red blood cell folate concentrations for neural tube defect prevention
Authors: Qi Yan Ping , Tinker Sarah , Berry Robert , Crider Krista
Published: November 2023

Background

A recent study reported that 22.8% of U.S. women of childbearing age have folate insufficiency, defined as red blood cell (RBC) folate below optimal concentrations needed for neural tube defect (NTD) prevention per guidelines established by the World Health Organization. Clinical trials have shown that consuming 400 μg of folic acid daily prevents NTDs.

Objective

We assessed the daily usual total folic acid intake and RBC folate status of women of childbearing age. We estimated the proportion of women consuming ≥400 μg folic acid/day, the daily amount recommended for NTD prevention for all women capable of becoming pregnant.

Methods

We used 2007–2012 data on non‐pregnant women aged 12–49 years (n = 4783) from the National Health and Nutrition Examination Survey (NHANES) and estimated daily usual total folic acid intake from all fortified foods and dietary supplements. Folate insufficiency was defined as an RBC folate concentration of <748 nmol/L using the NHANES microbiologic assay, which is associated with prevalence of NTDs of ≥9 cases per 10,000 live births.

Results

Among all women in our study, 21.2% (95% confidence interval [CI]: 18.0, 24.3) had an average total folic acid intake of ≥400 μg /day from fortified foods and supplements. The prevalence of folate insufficiency was 22.5% (95% CI: 20.3, 24.9). Among the subgroup of women with folate insufficiency (n = 1196), only 3.9% (95% CI: 2.0, 5.7) achieved the recommended daily intake of folic acid. Among all women in our study, median usual daily total folic acid intake was highest among non‐Hispanic Whites (264 μg) and lowest among non‐Hispanic Blacks (185 μg). However, among women with folate insufficiency, the median usual daily total folic acid intake did not differ by race/ethnicity. Among women with folate insufficiency, 69.7% (95%CI: 64.8, 74.1) had mandatorily fortified foods (i.e., enriched cereal grain products) as their only source of folic acid; 12.6% (95% CI: 9.7, 16.1) reported taking supplements containing folic acid in the previous 30 days. Among folate‐insufficient women who did not use supplements, less than 1% had usual total folic acid intake ≥400 μg/day.

Conclusions

The majority of U.S. women of childbearing age with RBC folate below the optimal concentration do not consume the amount of folic acid recommended for NTD prevention. Targeted programs and guidance might increase folic acid intake among groups of women at higher risks for folate insufficiency.

Support or Funding Information

This work was supported by the CDC.
Association Between One‐carbon Metabolism Indices and DNA Methylation Status in Maternal and Cord Blood
Authors: Park Hea Jin , Knight Anna K , Fleming Jennifer M , Hausman Dorothy B , Caudill Marie A , Malysheva Olga V , Kauwell Gail PA , Sokolow Andrew , Fisher Susan , Smith Alicia K , Bailey Lynn B
Published: November 2023

One‐carbon metabolism is a crucial component of metabolism in all cells and tissues supporting DNA methylation and DNA synthesis. It is critically important during pregnancy to ensure normal cell division and growth of fetal and maternal tissues; however, the impact of one‐carbon metabolism indices during pregnancy on DNA methylation has not been investigated. In this study, status of one‐carbon metabolism indices and DNA methylation in maternal blood and cord blood were measured. One‐carbon metabolism indices included serum folate, red blood cell folate, plasma folic acid, plasma 5‐methyltetrahydrofolate (5MTHF), plasma methionine, plasma choline and choline metabolites (dimethylglycine (DMG), betaine, trimethylamine N‐oxide), plasma homocysteine, plasma SAM, SAH and the ratio of SAM/SAH and plasma vitamin B12. Healthy pregnant women (n=28) were recruited at a local midwifery clinic (Athens Regional Midwifery Clinic, Athens, GA), and maternal blood was collected at baseline (<12wk gestation) and delivery. Umbilical cord blood from the mothers was also collected at delivery. DNA methylation in maternal and cord blood were measured across > 485,000 CpG sites using the Infinium Human Methylation 450 BeadChip. Using a linear mixed‐effects model, we examined the relationship between DNA methylation of each CpG site and gestational week to determine CpG sites that change over pregnancy in maternal blood. We identified 993 such CpG sites (FDR<.05), which were then interrogated for associations with one‐carbon metabolism indices. In maternal blood, a CpG site was associated with DMG levels after multiple test correction. Interestingly, in cord blood, methylation of three CpG sites was negatively associated with 5MTHF level (FDR<.05). These CpG sites were annotated to Myc‐associated Zinc finger protein (MAZ), discs large homolog 2 (DLG2), and paraneoplastic Ma antigen (PNMA1), which have previously been associated with cancer progression and neurological function. Results suggest a unique association between one‐carbon metabolism indices and methylation status of specific CpG sites in cord blood. Future research should address changes in methylation of these genes in studies of brain development and neural tube defects.

Support or Funding Information

Support provided by Georgia Experimental Agricultural Station, HATCH #GEO00706 and #GEO00707, Obesity Initiative at the University of Georgia (UGA) and UGA Office of Vice President for Research.
Relationships among one‐carbon nutrients status, DNA methylation at H19 differentially methylated region and the long interspersed nucleotide elements, and serum insulin‐like growth factor levels of pregnant women
Authors: Huang Kwang‐Ta , Shen Yu‐Li , Lee Chien‐Nan , Cheng Chin‐Pao , Ku Wei‐Chi , Huang Rwei‐Fen S.
Published: November 2023

Kwang‐Ta Huang1,2, Yu‐Li Shen3, Chien‐Nan Lee 4, Chin‐Pao Cheng5, Wei‐Chi Ku6, and Rwei‐Fen S. Huang1,4

1Ph.D. Program in Nutrition and Food Science, Fu Jen University

2LaBor Birth Center, Xinzhuang Dist., New Taipei City, Taiwan

3Department of Nutritional Science, Fu Jen University,

4Department of Gynecology and Obstetrics, National Taiwan University Hospital, Taipei;

5Dietetic Department, National Taiwan University Hospital, Taipei, Taiwan

5Department of Medicine, Medicine College, Fu Jen University, Taiwan

Aberrant methylation at the H19 differentially methylated region (H19 DMR) or imprinting center 1 (IC1) of cluster imprinted genes including insulin‐like growth factor (IGF2) during fetal development was associated with increased expression of IGF2 and increased chronic diseases risks in offspring. The early environmental factors to modify DNA methylation of the H19 DMR and IGF2 expressions remain unclear. In this study, we examined the determinants of maternal DNA methylation at the specific H19 DMR and the long interspersed nucleotide elements (LINE‐1), a one‐carbon nutrients responsive genomic methylation sensor, in PMBC of 116 first‐term pregnant females, and their associations with disease risk markers of serum IGF2. By linear regression analysis, RBC folate (beta = −0.235, P = 0.028) and plasma free choline levels (beta = −0.230, P = 0.026) were the most significant determinants of LINE‐1 methylation status in PMBC of subjects. The LINE‐1 methylation status was the most significant determinant of methylation status at H19 DMR (beta = −0.235, P = 0.028). Degree of PBMC LINE‐1 methylation was positively correlated with methylation at H19 DMR (r = 0.373, P < 0.001) and inversely associated with serum IGF2 levels (r = −0.199, P = 0.045). Serum folate (r = 0.258, P = 0.08) and betaine levels (r = 0.227, P = 0.026) were positively correlated with serum IGF2 levels, with no modifying effect on H19 DMR DMR. Plasma betaine level was the most significant determinant of serum IGF2 levels (beta = 0.223, P = 0.029). The data suggested that maternal H19 DMR corresponded to global LINE‐1 methylation which correlated with expression of serum IGF2 levels, which are modified by serum folate and betaine status of pregnant women. The data support the critical role of maternal one‐carbon nutrient status in modifying risks factors of chronic diseases during pregnancy.