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Rotarescu RD, Mathur M, Bejoy AM, Anderson GH, Metherel AH. Serum measures of docosahexaenoic acid (DHA) synthesis underestimates whole body DHA synthesis in male and female mice. J Nutr Biochem 2024; 131:109689. [PMID: 38876393 DOI: 10.1016/j.jnutbio.2024.109689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2024] [Revised: 06/06/2024] [Accepted: 06/09/2024] [Indexed: 06/16/2024]
Abstract
Females have higher docosahexaenoic acid (DHA) levels than males, proposed to be a result of higher DHA synthesis rates from α-linolenic acid (ALA). However, DHA synthesis rates are reported to be low, and have not been directly compared between sexes. Here, we apply a new compound specific isotope analysis model to determine n-3 PUFA synthesis rates in male and female mice and assess its potential translation to human populations. Male and female C57BL/6N mice were allocated to one of three 12-week dietary interventions with added ALA, eicosapentaenoic acid (EPA) or DHA. The diets included low carbon-13 (δ13C)-n-3 PUFA for four weeks, followed by high δ13C-n-3 PUFA for eight weeks (n=4 per diet, time point, sex). Following the diet switch, blood and tissues were collected at multiple time points, and fatty acid levels and δ13C were determined and fit to one-phase exponential decay modeling. Hepatic DHA synthesis rates were not different (P>.05) between sexes. However, n-3 docosapentaenoic acid (DPAn-3) synthesis from dietary EPA was 66% higher (P<.05) in males compared to females, suggesting higher synthesis downstream of DPAn-3 in females. Estimates of percent conversion of dietary ALA to serum DHA was 0.2%, in line with previous rodent and human estimates, but severely underestimates percent dietary ALA conversion to whole body DHA of 9.5%. Taken together, our data indicates that reports of low human DHA synthesis rates may be inaccurate, with synthesis being much higher than previously believed. Future animal studies and translation of this model to humans are needed for greater understanding of n-3 PUFA synthesis and metabolism, and whether the higher-than-expected ALA-derived DHA can offset dietary DHA recommendations set by health agencies.
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Affiliation(s)
- Ruxandra D Rotarescu
- Department of Nutritional Sciences, Temerty Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, Ontario, Canada
| | - Mahima Mathur
- Department of Nutritional Sciences, Temerty Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, Ontario, Canada
| | - Ashley M Bejoy
- Department of Nutritional Sciences, Temerty Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, Ontario, Canada
| | - G Harvey Anderson
- Department of Nutritional Sciences, Temerty Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, Ontario, Canada
| | - Adam H Metherel
- Department of Nutritional Sciences, Temerty Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, Ontario, Canada.
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2
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Smith ME, Bazinet RP. Unraveling brain palmitic acid: Origin, levels and metabolic fate. Prog Lipid Res 2024:101300. [PMID: 39222711 DOI: 10.1016/j.plipres.2024.101300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 08/26/2024] [Accepted: 08/28/2024] [Indexed: 09/04/2024]
Abstract
In the human brain, palmitic acid (16:0; PAM) comprises nearly half of total brain saturates and has been identified as the third most abundant fatty acid overall. Brain PAM supports the structure of membrane phospholipids, provides energy, and regulates protein stability. Sources underlying the origin of brain PAM are both diet and endogenous synthesis via de novo lipogenesis (DNL), primarily from glucose. However, studies investigating the origin of brain PAM are limited to tracer studies utilizing labelled (14C/11C/3H/2H) PAM, and results vary based on the model and tracer used. Nevertheless, there is evidence PAM is synthesized locally in the brain, in addition to obtained directly from the diet. Herein, we provide an overview of brain PAM origin, entry to the brain, metabolic fate, and factors influencing brain PAM kinetics and levels, the latter in the context of age, as well as neurological diseases and psychiatric disorders. Additionally, we briefly summarize the role of PAM in signaling at the level of the brain. We add to the literature a rudimentary summary on brain PAM metabolism.
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Affiliation(s)
- Mackenzie E Smith
- Department of Nutritional Sciences, University of Toronto, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada
| | - Richard P Bazinet
- Department of Nutritional Sciences, University of Toronto, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada.
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3
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Tripicchio GL, Smethers AD, Johnson JJ, Olenginski JA, O'Brien DM, Fisher JO, Robinson VA, Nash SH. The Carbon Isotope Ratio as an Objective Biomarker of Added Sugar Intake: A Scoping Review of Current Evidence in Human Nutrition. Adv Nutr 2024; 15:100281. [PMID: 39094908 DOI: 10.1016/j.advnut.2024.100281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Revised: 06/05/2024] [Accepted: 07/29/2024] [Indexed: 08/04/2024] Open
Abstract
Objective biomarkers of dietary intake are needed to advance nutrition research. The carbon isotope ratio (C13/C12; CIR) holds promise as an objective biomarker of added sugar (AS) and sugar-sweetened beverage (SSB) intake. This systematic scoping review presents the current evidence on CIRs from human studies. Search results (through April 12, 2024) yielded 6297 studies and 24 final articles. Studies were observational (n = 12), controlled feeding (n = 10), or dietary interventions (n = 2). CIRs were sampled from blood (n = 23), hair (n = 5), breath (n = 2), and/or adipose tissue (n = 1). Most (n = 17) conducted whole tissue (that is, bulk) analysis, 8 used compound specific isotope analysis (CSIA), and/or 2 studies used methods appropriate for analyzing breath. Studies were conducted in 3 concentrated geographic regions of the United States (n = 7 Virginia; n = 5 Arizona; n = 4 Alaska), with only 2 studies conducted in other countries. Studies that used CSIA to examine the CIR from the amino acid alanine (CIR-Ala; n = 4) and CIR analyzed from breath (n = 2) provided the most robust evidence for CIR as an objective biomarker of AS and SSBs (R2 range 0.36-0.91). Studies using bulk analysis of hair or blood showed positive, but modest and more variable associations with AS and SSBs (R2 range 0.05-0.48). Few studies showed no association, particularly in non-United States populations and those with low AS and SSB intakes. Two studies provided evidence for CIR to detect changes in SSB intake in response to dietary interventions. Overall, the most compelling evidence supports CIR-Ala as an objective indicator of AS intake and breath CIR as an indicator of short-term AS intake. Considering how to adjust for underlying dietary patterns remains an important area of future work and emerging methods using breath and CSIA warrant additional investigation. More evidence is needed to refine the utility and specificity of CIRs to measure AS and SSB intake.
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Affiliation(s)
- Gina L Tripicchio
- Center for Obesity Research and Education, Temple University, PA, United States; Department of Social and Behavioral Sciences, Temple University, PA, United States.
| | - Alissa D Smethers
- Department of Social and Behavioral Sciences, Temple University, PA, United States
| | - Jessica J Johnson
- Institute of Arctic Biology, Department of Biology and Wildlife, University of Alaska Fairbanks, Fairbanks, AK, United States
| | - Jordan A Olenginski
- Center for Obesity Research and Education, Temple University, PA, United States; Drexel University College of Medicine, PA, United States
| | - Diane M O'Brien
- Institute of Arctic Biology, Department of Biology and Wildlife, University of Alaska Fairbanks, Fairbanks, AK, United States
| | - Jennifer Orlet Fisher
- Center for Obesity Research and Education, Temple University, PA, United States; Department of Social and Behavioral Sciences, Temple University, PA, United States
| | - Vitalina A Robinson
- Social Sciences and Clark Library, University of Michigan, Ann Arbor, MI, United States
| | - Sarah H Nash
- Department of Epidemiology, University of Iowa, IA, United States
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4
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Metherel AH, Valenzuela R, Klievik BJ, Cisbani G, Rotarescu RD, Gonzalez-Soto M, Cruciani-Guglielmacci C, Layé S, Magnan C, Mutch DM, Bazinet RP. Dietary docosahexaenoic acid (DHA) downregulates liver DHA synthesis by inhibiting eicosapentaenoic acid elongation. J Lipid Res 2024; 65:100548. [PMID: 38649096 PMCID: PMC11126934 DOI: 10.1016/j.jlr.2024.100548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Revised: 04/13/2024] [Accepted: 04/18/2024] [Indexed: 04/25/2024] Open
Abstract
DHA is abundant in the brain where it regulates cell survival, neurogenesis, and neuroinflammation. DHA can be obtained from the diet or synthesized from alpha-linolenic acid (ALA; 18:3n-3) via a series of desaturation and elongation reactions occurring in the liver. Tracer studies suggest that dietary DHA can downregulate its own synthesis, but the mechanism remains undetermined and is the primary objective of this manuscript. First, we show by tracing 13C content (δ13C) of DHA via compound-specific isotope analysis, that following low dietary DHA, the brain receives DHA synthesized from ALA. We then show that dietary DHA increases mouse liver and serum EPA, which is dependant on ALA. Furthermore, by compound-specific isotope analysis we demonstrate that the source of increased EPA is slowed EPA metabolism, not increased DHA retroconversion as previously assumed. DHA feeding alone or with ALA lowered liver elongation of very long chain (ELOVL2, EPA elongation) enzyme activity despite no change in protein content. To further evaluate the role of ELOVL2, a liver-specific Elovl2 KO was generated showing that DHA feeding in the presence or absence of a functional liver ELOVL2 yields similar results. An enzyme competition assay for EPA elongation suggests both uncompetitive and noncompetitive inhibition by DHA depending on DHA levels. To translate our findings, we show that DHA supplementation in men and women increases EPA levels in a manner dependent on a SNP (rs953413) in the ELOVL2 gene. In conclusion, we identify a novel feedback inhibition pathway where dietary DHA downregulates its liver synthesis by inhibiting EPA elongation.
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Affiliation(s)
- Adam H Metherel
- Department of Nutritional Sciences, University of Toronto, Toronto, ON, Canada.
| | | | - Brinley J Klievik
- Department of Nutritional Sciences, University of Toronto, Toronto, ON, Canada
| | - Giulia Cisbani
- Department of Nutritional Sciences, University of Toronto, Toronto, ON, Canada
| | | | - Melissa Gonzalez-Soto
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada
| | | | - Sophie Layé
- INRA, Bordeaux INP, NutriNeuro, Université de Bordeaux, Bordeaux, France
| | | | - David M Mutch
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada
| | - Richard P Bazinet
- Department of Nutritional Sciences, University of Toronto, Toronto, ON, Canada
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5
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Agrawal G, Sanyal P. Discerning animal-sourced food in diet using isotope analysis of human scalp hair and fingernails. Eur J Nutr 2024; 63:409-423. [PMID: 38006443 DOI: 10.1007/s00394-023-03273-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Accepted: 10/20/2023] [Indexed: 11/27/2023]
Abstract
PURPOSE Diet-related diseases are advancing as the leading cause of death globally. As self-reporting of diet by patients can be associated with errors, stable isotopes of human tissues can be used to diagnose diseases, understand physiology, and detect change in diet. This study investigates the effect of type and amount of food on the nitrogen and carbon concentration (Nconc and Cconc) and isotopic composition (δ15N and δ13C) in human scalp hair and fingernails. METHODS A total of 100 residents participated in the study whereas only 74 individuals provided complete diet history. Sixty-six food items majorly available to them were also collected. The Nconc, Cconc, δ15N and δ13C values of human hair, nails and food items were determined. RESULTS The Nconc, Cconc, δ15N and δ13C values between plant-sourced and animal-sourced food items, as well as human hair and nail tissue were significantly different (p < 0.05). The δ15N value of human tissues was distinct between lacto-vegetarians and omnivores by 0.9‰. The δ15N and δ13C values of human tissues increased by 0.4-0.5‰ with every 5% increase in the consumption of animal protein. CONCLUSIONS The study helps to demarcate lacto-vegetarians from omnivores, and estimate the percentage of animal protein in diet based on the dual isotope values of human tissues. It also acts as a reference to determine isotopic composition of hair tissue provided the isotope value of nail tissue is known and vice versa.
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Affiliation(s)
- Gunjan Agrawal
- Department of Earth Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, 741246, India.
| | - Prasanta Sanyal
- Department of Earth Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, 741246, India
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6
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Smith ME, Chen CT, Gohel CA, Cisbani G, Chen DK, Rezaei K, McCutcheon A, Bazinet RP. Upregulated hepatic lipogenesis from dietary sugars in response to low palmitate feeding supplies brain palmitate. Nat Commun 2024; 15:490. [PMID: 38233416 PMCID: PMC10794264 DOI: 10.1038/s41467-023-44388-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 12/12/2023] [Indexed: 01/19/2024] Open
Abstract
Palmitic acid (PAM) can be provided in the diet or synthesized via de novo lipogenesis (DNL), primarily, from glucose. Preclinical work on the origin of brain PAM during development is scarce and contrasts results in adults. In this work, we use naturally occurring carbon isotope ratios (13C/12C; δ13C) to uncover the origin of brain PAM at postnatal days 0, 10, 21 and 35, and RNA sequencing to identify the pathways involved in maintaining brain PAM, at day 35, in mice fed diets with low, medium, and high PAM from birth. Here we show that DNL from dietary sugars maintains the majority of brain PAM during development and is augmented in mice fed low PAM. Importantly, the upregulation of hepatic DNL genes, in response to low PAM at day 35, demonstrates the presence of a compensatory mechanism to maintain total brain PAM pools compared to the liver; suggesting the importance of brain PAM regulation.
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Affiliation(s)
- Mackenzie E Smith
- Department of Nutritional Sciences, University of Toronto, 1 King's College Circle, Toronto, M5S 1A8, ON, Canada
| | - Chuck T Chen
- Department of Nutritional Sciences, University of Toronto, 1 King's College Circle, Toronto, M5S 1A8, ON, Canada
| | - Chiraag A Gohel
- Department of Biostatistics and Bioinformatics, George Washington University, 950 New Hampshire Ave, NW, Washington, DC, 20052, USA
| | - Giulia Cisbani
- Department of Nutritional Sciences, University of Toronto, 1 King's College Circle, Toronto, M5S 1A8, ON, Canada
| | - Daniel K Chen
- Department of Nutritional Sciences, University of Toronto, 1 King's College Circle, Toronto, M5S 1A8, ON, Canada
| | - Kimia Rezaei
- Department of Nutritional Sciences, University of Toronto, 1 King's College Circle, Toronto, M5S 1A8, ON, Canada
| | - Andrew McCutcheon
- Department of Nutritional Sciences, University of Toronto, 1 King's College Circle, Toronto, M5S 1A8, ON, Canada
| | - Richard P Bazinet
- Department of Nutritional Sciences, University of Toronto, 1 King's College Circle, Toronto, M5S 1A8, ON, Canada.
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7
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Cisbani G, Chouinard-Watkins R, Smith ME, Malekanian A, Valenzuela R, Metherel AH, Bazinet RP. Dietary triacetin, but not medium chain triacylglycerides, blunts weight gain in diet-induced rat model of obesity. Lipids 2023; 58:257-270. [PMID: 37997471 DOI: 10.1002/lipd.12381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 10/16/2023] [Accepted: 10/23/2023] [Indexed: 11/25/2023]
Abstract
Consumption of a Western diet (WD) is known to increase the risk of obesity. Short or medium chain fatty acids influence energy metabolism, and triacetin, a synthetic short chain triacylglyceride, has been shown to lower body fat under normal conditions. This study aimed to investigate if triacetin as part of a WD modifies rat weight and body fat. Male rats were fed a control diet or WD for 8 weeks. At week 8, rats in the WD group were maintained on a WD diet or switched to a WD diet containing 30% energy from medium-chain triacylglyceride (WD-MCT) or triacetin (WD-T) for another 8 weeks. At week 16, rats were euthanized and liver, adipose and blood were collected. Tissue fatty acids (FAs) were quantified by gas chromatography (GC) and hepatic FAs were measured by GC-combustion-isotope ratio mass spectrometry for δ13 C-palmitic acid (PAM)-a novel marker of de novo lipogenesis (DNL). Rats fed WD-T had a body weight not statistically different to the control group, and gained less body weight than rats fed WD alone. Furthermore, WD-T fed rats had a lower fat mass, and lower total liver and plasma FAs compared to the WD group. Rats fed WD-T did not differ from WD in blood ketone or glucose levels, however, had a significantly lower hepatic δ13 C-PAM value than WD fed rats; suggestive of lower DNL. In summary, we show that triacetin has the potential to blunt weight gain and adipose tissue accumulation in a rodent model of obesity, possibly due to a decrease in DNL.
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Affiliation(s)
- Giulia Cisbani
- Department of Nutritional Sciences, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Raphaël Chouinard-Watkins
- Department of Nutritional Sciences, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Mackenzie E Smith
- Department of Nutritional Sciences, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Arezou Malekanian
- Department of Nutritional Sciences, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Rodrigo Valenzuela
- Nutrition Department, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Adam H Metherel
- Department of Nutritional Sciences, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Richard P Bazinet
- Department of Nutritional Sciences, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
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8
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Wang YY, Yang F, Chen J, Li YJ, Zhou J, Qing X, Yan D, Lu X, Zhou P, Zhang L. Multidimensional isotope analysis of carbon, hydrogen, and oxygen as a tool for traceability of lactose in drug products. J Pharm Biomed Anal 2023; 226:115270. [PMID: 36716528 DOI: 10.1016/j.jpba.2023.115270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 12/31/2022] [Accepted: 01/23/2023] [Indexed: 01/26/2023]
Abstract
Lactose is one of the most commonly used pharmaceutical excipients. Depending on manufactures, the properties of lactose are very different, which could impact the pharmacokinetic behavior of drug products. Therefore, it is very important to trace the origin of pharmaceutical lactose in drug products which is valuable for prescription analysis. In this study, the carbon, hydrogen and oxygen isotope ratios (δ13C, δ2H and δ18O) of thirty-four lactose from seven manufacturers were analyzed by elemental analysis-stable isotope ratio mass spectrometry (EA-IRMS). One-way analysis of variance (ANOVA) and Duncan's test indicated significant differences in isotope ratios of lactose from different origins. To identify the lactose manufacturer, a discrimination model was generated through linear discriminant analysis (LDA). Based on this model, the manufacturers of lactose used in three drug products were successfully identified. Our results suggested that the multidimensional analysis of δ13C, δ2H and δ18O of lactose provided a fast and effective method to trace the lactose manufacturer. In conclusion, this method can be used to analyze the prescription of the drug product quickly, which could speed up the development of generic drug product.
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Affiliation(s)
- Yu-Ye Wang
- Instrumental Analysis Center, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China; School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Fan Yang
- Instrumental Analysis Center, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Jian Chen
- School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Ying-Jian Li
- Department of Formulation Development, Boehringer Ingelheim Animal Health, North Brunswick, NJ, 08902 USA
| | - Jia Zhou
- Instrumental Analysis Center, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Xia Qing
- Instrumental Analysis Center, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Dong Yan
- Dasan Pharmaceutical Technology Co. Ltd., 860-1, Shangshengou, Shenyang 110179, China
| | - Xin Lu
- Research & Development department, Shanghai Anbison Lab Co., Ltd., No.889 YiShan Road, Shanghai 200233, China
| | - Peng Zhou
- DAOMO (Shanghai) Industrial Co.,Ltd, 7577 Hunan Road, Shanghai 201314, China
| | - Li Zhang
- Instrumental Analysis Center, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China.
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9
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Lacombe RJS, Smith ME, Perlman K, Turecki G, Mechawar N, Bazinet RP. Quantitative and carbon isotope ratio analysis of fatty acids isolated from human brain hemispheres. J Neurochem 2023; 164:44-56. [PMID: 36196762 DOI: 10.1111/jnc.15702] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 08/22/2022] [Accepted: 09/29/2022] [Indexed: 02/04/2023]
Abstract
Our knowledge surrounding the overall fatty acid profile of the adult human brain has been largely limited to extrapolations from brain regions in which the distribution of fatty acids varies. This is especially problematic when modeling brain fatty acid metabolism, therefore, an updated estimate of whole-brain fatty acid concentration is necessitated. Here, we sought to conduct a comprehensive quantitative analysis of fatty acids from entire well-characterized human brain hemispheres (n = 6) provided by the Douglas-Bell Canada Brain Bank. Additionally, exploratory natural abundance carbon isotope ratio (CIR; δ13 C, 13 C/12 C) analysis was performed to assess the origin of brain fatty acids. Brain fatty acid methyl esters (FAMEs) were quantified by gas chromatography (GC)-flame ionization detection and minor n-6 and n-3 polyunsaturated fatty acid pentafluorobenzyl esters by GC-mass spectrometry. Carbon isotope ratio values of identifiable FAMEs were measured by GC-combustion-isotope ratio mass spectrometry. Overall, the most abundant fatty acid in the human brain was oleic acid, followed by stearic acid (STA), palmitic acid (PAM), docosahexaenoic acid (DHA), and arachidonic acid (ARA). Interestingly, cholesterol as well as saturates including PAM and STA were most enriched in 13 C, while PUFAs including DHA and ARA were most depleted in 13 C. These findings suggest a contribution of endogenous synthesis utilizing dietary sugar substrates rich in 13 C, and a combination of marine, animal, and terrestrial PUFA sources more depleted in 13 C, respectively. These results provide novel insights on cerebral fatty acid origin and concentration, the latter serving as a valuable resource for future modeling of fatty acid metabolism in the human brain.
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Affiliation(s)
- R J Scott Lacombe
- Department of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada
| | - Mackenzie E Smith
- Department of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada
| | - Kelly Perlman
- McGill Group for Suicide Studies, Douglas Mental Health University Institute, Verdun, Quebec, Canada
| | - Gustavo Turecki
- McGill Group for Suicide Studies, Douglas Mental Health University Institute, Verdun, Quebec, Canada.,Department of Psychiatry, McGill University, Montreal, Quebec, Canada
| | - Naguib Mechawar
- McGill Group for Suicide Studies, Douglas Mental Health University Institute, Verdun, Quebec, Canada.,Department of Psychiatry, McGill University, Montreal, Quebec, Canada
| | - Richard P Bazinet
- Department of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada
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10
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Chen CT, Shao Z, Fu Z. Dysfunctional peroxisomal lipid metabolisms and their ocular manifestations. Front Cell Dev Biol 2022; 10:982564. [PMID: 36187472 PMCID: PMC9524157 DOI: 10.3389/fcell.2022.982564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 08/17/2022] [Indexed: 11/13/2022] Open
Abstract
Retina is rich in lipids and dyslipidemia causes retinal dysfunction and eye diseases. In retina, lipids are not only important membrane component in cells and organelles but also fuel substrates for energy production. However, our current knowledge of lipid processing in the retina are very limited. Peroxisomes play a critical role in lipid homeostasis and genetic disorders with peroxisomal dysfunction have different types of ocular complications. In this review, we focus on the role of peroxisomes in lipid metabolism, including degradation and detoxification of very-long-chain fatty acids, branched-chain fatty acids, dicarboxylic acids, reactive oxygen/nitrogen species, glyoxylate, and amino acids, as well as biosynthesis of docosahexaenoic acid, plasmalogen and bile acids. We also discuss the potential contributions of peroxisomal pathways to eye health and summarize the reported cases of ocular symptoms in patients with peroxisomal disorders, corresponding to each disrupted peroxisomal pathway. We also review the cross-talk between peroxisomes and other organelles such as lysosomes, endoplasmic reticulum and mitochondria.
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Affiliation(s)
- Chuck T Chen
- Department of Nutritional Sciences, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Zhuo Shao
- Post-Graduate Medical Education, University of Toronto, Toronto, ON, Canada
- Division of Clinical and Metabolic Genetics, the Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
- The Genetics Program, North York General Hospital, University of Toronto, Toronto, ON, Canada
| | - Zhongjie Fu
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States
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11
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Cisbani G, Koppel A, Metherel AH, Smith ME, Aji KN, Andreazza AC, Mizrahi R, Bazinet RP. Serum lipid analysis and isotopic enrichment is suggestive of greater lipogenesis in young long-term cannabis users: A secondary analysis of a case-control study. Lipids 2022; 57:125-140. [PMID: 35075659 PMCID: PMC8923992 DOI: 10.1002/lipd.12336] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 12/27/2021] [Accepted: 12/28/2021] [Indexed: 01/15/2023]
Abstract
Cannabis is now legal in many countries and while numerous studies have reported on its impact on cognition and appetite regulation, none have examined fatty acid metabolism in young cannabis users. We conducted an exploratory analysis to evaluate cannabis impact on fatty acid metabolism in cannabis users (n = 21) and non-cannabis users (n = 16). Serum levels of some saturated and monounsaturated fatty acids, including palmitic, palmitoleic, and oleic acids were higher in cannabis users compared to nonusers. As palmitic acid can be derived from diet or lipogenesis from sugars, we evaluated lipogenesis using a de novo lipogenesis index (palmitate/linoleic acid) and carbon-specific isotope analysis, which allows for the determination of fatty acid 13 C signature. The significantly higher de novo lipogenesis index in the cannabis users group along with a more enriched 13 C signature of palmitic acid suggested an increase in lipogenesis. In addition, while serum glucose concentration did not differ between groups, pyruvate and lactate were lower in the cannabis user group, with pyruvate negatively correlating with palmitic acid. Furthermore, the endocannabinoid 2-arachidonoylglycerol was elevated in cannabis users and could contribute to lipogenesis by activating the cannabinoid receptor 1. Because palmitic acid has been suggested to increase inflammation, we measured peripheral cytokines and observed no changes in inflammatory cytokines. Finally, an anti-inflammatory metabolite of palmitic acid, palmitoylethanolamide was elevated in cannabis users. Our results suggest that lipogenic activity is increased in cannabis users; however, future studies, including prospective studies that control dietary intake are required.
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Affiliation(s)
- Giulia Cisbani
- Department of Nutritional Sciences, Temerty Faculty of Medicine, University of Toronto, Canada
| | - Alex Koppel
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada; Department of Psychiatry, University of Toronto, Toronto, Ontario
| | - Adam H. Metherel
- Department of Nutritional Sciences, Temerty Faculty of Medicine, University of Toronto, Canada
| | - Mackenzie E. Smith
- Department of Nutritional Sciences, Temerty Faculty of Medicine, University of Toronto, Canada
| | - Kankana N. Aji
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada; Department of Psychiatry, University of Toronto, Toronto, Ontario
| | - Ana C. Andreazza
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada; Department of Psychiatry, University of Toronto, Toronto, Ontario
| | - Romina Mizrahi
- Department of Psychiatry, McGill University, Montreal, Canada,Douglas Research Center, Montreal, Canada,Corresponding author: Richard P. Bazinet, Department of Nutritional Sciences, Temerty Faculty of Medicine, University of Toronto, Canada, Medical Sciences Building, 5th Floor, Room 5358, 1 King’s College Circle, Toronto, ON, M5S 1A8, , Phone number: (416) 946-8276, Romina Mizrahi, Department of Psychiatry, McGill University, 6875 Boulevard Lasalle, Montréal, QC H4H 1R3,
| | - Richard P. Bazinet
- Department of Nutritional Sciences, Temerty Faculty of Medicine, University of Toronto, Canada,Corresponding author: Richard P. Bazinet, Department of Nutritional Sciences, Temerty Faculty of Medicine, University of Toronto, Canada, Medical Sciences Building, 5th Floor, Room 5358, 1 King’s College Circle, Toronto, ON, M5S 1A8, , Phone number: (416) 946-8276, Romina Mizrahi, Department of Psychiatry, McGill University, 6875 Boulevard Lasalle, Montréal, QC H4H 1R3,
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O'Brien DM, Sagi-Kiss V, Palma-Duran SA, Cunningham C, Barrett B, Johnston CS, Midthune D, Kipnis V, Freedman LS, Tasevska N. An evaluation of the serum carbon isotope ratio as a candidate predictive biomarker of the dietary animal protein ratio (animal protein/total protein) in a 15-day controlled feeding study of US adults. Am J Clin Nutr 2022; 115:1134-1143. [PMID: 35030258 PMCID: PMC8970990 DOI: 10.1093/ajcn/nqac004] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 01/10/2022] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND The serum natural abundance carbon isotope ratio (CIR) was recently identified as a candidate biomarker of animal protein intake in postmenopausal women. Such a biomarker would help clarify the relation between dietary protein source (plant or animal) and chronic disease risk. OBJECTIVES We aimed to evaluate the performance of the serum CIR as a biomarker of dietary protein source in a controlled feeding study of men and women of diverse age and BMI. METHODS We conducted a 15-d feeding study of 100 adults (age: 18-70 y, 55% women) in Phoenix, AZ. Participants were provided individualized diets that approximated habitual food intakes. Serum was collected at the end of the feeding period for biomarker measurements. RESULTS Median [IQR] animal protein intake was 67 g/d [55-88 g/d], which was 64% of total protein. The serum CIR was positively correlated with animal protein and inversely correlated with plant protein intake, leading to a strong correlation (r2 = 0.76) with the dietary animal protein ratio (APR; animal/total protein). Regressing serum CIR on the APR, serum nitrogen isotope ratio (NIR), gender, age, and body weight generated an R2 of 0.78. Following the measurement error model for predictive biomarkers, the resulting regression equation was then inverted to develop a calibrated biomarker equation for APR. Added sugars ratio (added/total sugars intake) and corn intakes also influenced the serum CIR but to a much lesser degree than the APR; variations in these intakes had only small effects on biomarker-estimated APR. CONCLUSIONS Based on our findings in this US cohort of mixed sex and age, we propose the serum CIR alongside NIR as a predictive dietary biomarker of the APR. We anticipate using this biomarker to generate calibrated estimates based on self-reported intake and ultimately to obtain more precise disease risk estimates according to dietary protein source.
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Affiliation(s)
| | - Virag Sagi-Kiss
- Present address for VS-K: School of Medicine, Imperial College London, London, United Kingdom
| | | | | | - Brian Barrett
- Information Management Services, Inc., Rockville, MD, USA
| | - Carol S Johnston
- College of Health Solutions, Arizona State University, Phoenix, AZ, USA
| | - Douglas Midthune
- Division of Cancer Prevention, National Cancer Institute, Bethesda, MD, USA
| | - Victor Kipnis
- Division of Cancer Prevention, National Cancer Institute, Bethesda, MD, USA
| | - Laurence S Freedman
- Gertner Institute for Epidemiology and Health Policy Research, Sheba Medical Center, Tel Hashomer, Israel
| | - Natasha Tasevska
- College of Health Solutions, Arizona State University, Phoenix, AZ, USA
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Smith ME, Cisbani G, Metherel AH, Bazinet RP. The Majority of Brain Palmitic Acid is Maintained by Lipogenesis from Dietary Sugars and is Augmented in Mice fed Low Palmitic Acid Levels from Birth. J Neurochem 2021; 161:112-128. [PMID: 34780089 DOI: 10.1111/jnc.15539] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 11/04/2021] [Accepted: 11/10/2021] [Indexed: 11/28/2022]
Abstract
Previously, results from studies investigating if brain palmitic acid (16:0; PAM) was maintained by either dietary uptake or lipogenesis de novo (DNL) varied. Here, we utilize naturally occurring carbon isotope ratios (13 C/12 C; δ13 C) to uncover the origin of brain PAM. Additionally, we explored brain and liver fatty acid concentration, total brain metabolomic profile, and behaviour. BALB/c dams were equilibrated onto either a low PAM diet (LP; <2%) or high PAM diet (HP; >95%) prior to producing one generation of offspring. Offspring stayed on the respective diet of the dam until 15-weeks of age, at which time the Open Field test was conducted in the offspring, prior to euthanasia and tissue lipid extraction. Although liver PAM was lower in offspring fed the LP diet, as well as female offspring, brain PAM was not affected by diet or sex. Across offspring of either sex on both diets, brain 13 C-PAM revealed compared to dietary uptake, DNL from dietary sugars contributed 68.8%-79.5% and 46.6%-58.0% to the total brain PAM pool by both peripheral and local brain DNL, and local brain DNL alone, respectively. DNL was augmented in offspring fed the LP diet, and the ability to upregulate DNL in the liver or the brain depended on sex. Anxiety-like behaviours were decreased in offspring fed the LP diet and were correlated with markers of LP diet consumption including increased liver 13 C-PAM, warranting further investigation. Altogether, our results indicate that DNL from dietary sugars is a compensatory mechanism to maintain brain PAM in response to a LP diet.
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Affiliation(s)
| | - Giulia Cisbani
- University of Toronto, Department of Nutritional Sciences, Toronto
| | - Adam H Metherel
- University of Toronto, Department of Nutritional Sciences, Toronto
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