Progress 10/01/16 to 09/30/21
Outputs
Target Audience:The target audience is the consumer. To reach the consumers, we present our results at professional meetings where the public health professionals attend. We alsopublish our findings in well-read journals. Public health professionals and public policy groups make recommendations to consumers. If we are successful, it will become clearer to the public health professional that set policy and to the American population that we are not consuming sufficient natural vitamin E from vegetable oils. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest?We now have published sixpeer-reviewed manuscript from this work. In addition, Katherine Ranard completed her Ph.D. thesis in 2020 entitled "Natural vs. Synthetic α -tocopherol (vitamin E) using cell and animal models". Most of this work has been presented several times at national meetings in poster or oral formats. Study 1 results were published in 2019. Citation: Ranard KM, Kuchan MJ & J.W Erdman Jr. α-Tocopherol, but not γ-tocopherol, attenuates the expression of selective TNF-α-induced genes in primary human aortic cell lines. Lipids. (2019) 54:289-299. doi:10.1002/lipd.12149. Study 2 results were published in 2021. Citation: Jeon, S., Q. Li., K.M. Ranard, S.S. Rubakhin, J.V. Sweedler, M.J. Kuchan & J.W. Erdman Jr. Nutrition Research. (2021) 93:79-86. Doi.org/10.1016/j.nutres.2021.07.005. Study 3: Both the adolescent and adult studies have yielded publications. Citation: Ranard, K.M., M.J. Kuchan, J.M. Juraska, R. Bruno & J.W. Erdman Jr., 2020. Synthetic, compared to natural α-tocopherol, downregulates myelination genes in cerebella of adolescent α-tocopherol transport protein-null mice. J. Nutrition. 150:1031-40 Doi.org/10.1093/jn/nxz330. Citation: Ranard KM, Kuchan MJ, Juraska JM & J.W. Erdman Jr. Natural and synthetic α-tocopherol modulate the neuroinflammatory response in the spinal cord of adult Ttpa-null mice. Current Developments in Nutrition (2021) doi:10.1093/cdn/nzab008. Citation: Ranard, K.M., M.J. Kuchan & J.W. Erdman Jr. 2020. Breeder diet strategies for generating Ttpa-null and wild type mice with marginal vitamin E status to assess neurological outcomes. Current Developments in Nutrition doi.org/10.1093/cdn/nzaa155. Citation: Ranard KM & J.W. Erdman Jr. Effects of dietary RRR vs. all-racemic α-tocopherol on health outcomes. Nutrition Reviews (2018) 76(3):141-153. doi:10.1093/nutrit/nux067. What do you plan to do during the next reporting period to accomplish the goals?We have initiating breeding mice for two new studies with the objective of assessing how different dietary levels of natural α-T affect markers of oxidative stress following LPS treatment in adult Ttpa-/- mice.
Impacts
What was accomplished under these goals?
Study 1: Biological effects of RRR-α-tocopherol, all-rac α-tocopherol, and γ-tocopherol Dietary alpha tocopherol (α-T) and gamma tocopherol (γ-T) may differentially impact inflammation and influence cardiovascular outcomes, in part by modulating gene expression. The goal of this study was to compare the effects of RRR-α-tocopherol (natural α-T), all-rac α-tocopherol (synthetic α-T), and γ-T on gene expression in two human aortic cell lines. Specifically, human aortic smooth muscle cells and endothelial cells were either: (1) Treated with 25 μM tocopherols alone, or (2) Pretreated with tocopherols prior to a pro-inflammatory cytokine (tumor necrosis factor alpha, TNFα) stimulation. We found that tocopherol treatments alone did not significantly modulate the expression of genes in unstimulated HASMC or HAEC cells. TNFα stimulation significantly upregulated genes involved with apoptosis and stress response in both cell lines. Pretreating cells with tocopherols did not normalize the gene expression changes induced by TNFα. However, α-T pretreatments, but not γ-T pretreatments, attenuated TNF expression in both HASMC and HAEC cells. Study 2: In vivo bio-distribution of 13C α-tocopherol in marginally vitamin E deficient mice Natural (RRR-) α-T is more bioactive than synthetic (all racemic, all rac-) α-T, but little is known about the tissue uptake and distribution kinetics of the two α-T sources. The goal was to compare time-course bioaccumulation of natural vs. synthetic α-T in tissues of young, marginally vitamin E-deficient mice using 13C-(RRR-) α-T and 13C-all rac-α-T tracers. To measure α-T tissue depletion over time, three-week old male wild-type mice were fed a vitamin E-deficient diet for 0, 1, 2, or 3 weeks (n=5/time point) (Experiment 1). In Experiment 2, following a two-week α-T-depletion period (established from results of Experiment 1), mice were administered a single oral dose of 0.5 mg of 13C-RRR-α-T or 13C-all rac-α-T. At 12 hours, 1, 2, and 4 days post dose, plasma and tissues were collected (n=3/time point). α-T was quantified by HPLC, and 13C-α-T tissue enrichment was determined my mass spectrometry. Both sources of 13C-α-T reached maximum serum levels at 12 hours post dose. 13C-RRR-α-T levels were significantly higher than 13C-all rac-α-T in serum at 1 day post-dose, and in heart, lungs, and kidneys at 2 days post-dose. In brain, 13C-RRR-α-T concentrations were significantly higher than 13C-all rac-α-T at 2 and 4 days post-dose. At 4 days post-dose, 13C-α-T levels were similar between the 2 sources in examined tissues except for brain and adipose tissue where 13C-RRR-αT was higher. Overall, α-T bioaccumulation over time varied substantially depending on α-T source and tissue evaluated. Study 3: Effects of RRR- vs. all-rac α-T on the nervous system in adolescent and adult Ttpa-/- mice Humans with vitamin E deficiency have neurological disorders, such as cerebellar ataxia. Similarly, α-tocopherol transfer protein knockout (Ttpa−/−) mice have low α-T levels and develop neurological symptoms. The structural and behavioral manifestations of vitamin E deficiency are likely preceded by abnormalities in the transcriptome, but it is unknown how early these changes occur. Additionally, RRR- (natural) α-T is more biopotent than all-rac (synthetic) α-T, and they may differentially affect gene expression. Therefore, we assessed the effects of dietary α-T stereoisomer composition and dose on tissue α-T accumulation and cerebellar gene expression in adolescent and adult α-T transfer protein-null (Ttpa-/-) mice. An adolescent mouse study where weaning, male Ttpa-/- mice were fed either vitamin E-deficient diet (VED), natural α-T-supplemented diet (NAT), synthetic α-T-supplemented diet (SYN), or high synthetic α-T-supplemented diet (HYSN) for sevenweeks was completed and the work published. An adult Ttpa-/- mouse study used the same α-T diets as the adolescent mouse study to maximize comparisons between life stages. For the adult study, weanling mice were fed their respective diets until tenmonths of age. We conducted analyses on both the spinal cord and cerebellum, as α-T-deficiency pathologies have been detected in these two tissues. Spinal cords of VED-fed mice had increased expression of neuro-inflammatory genes, such as Tnf and Ccl2. Both α-T sources normalized this outcome in the spinal cord. Cerebellar pathology was not evident in our tenmonth old Ttpa-/- mice; the histological aberrations may only occur during late adulthood. The spinal cord appeared to be particularly sensitive to α-T status, and the molecular findings aligned with the known morphological and neurobehavioral deficits that accompany α-T deficiency.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2019
Citation:
Ranard, K.M., Kuchan, M.J. and J.W Erdman Jr. 2019. alpha-Tocopherol, but not gamma-tocopherol, attenuates the expression of selective TNF-alpha-induced genes in primary human aortic cell lines. Lipids. (2019) 54:289-299. doi:10.1002/lipd.12149.
- Type:
Journal Articles
Status:
Published
Year Published:
2021
Citation:
Jeon, S., Q. Li., K.M. Ranard, S.S. Rubakhin, J.V. Sweedler, M.J. Kuchan and J.W. Erdman Jr. 2021. Nutrition Research. 93:79-86. Doi.org/10.1016/j.nutres.2021.07.005.
- Type:
Journal Articles
Status:
Published
Year Published:
2020
Citation:
Ranard, K.M., M.J. Kuchan, J.M. Juraska, R. Bruno and J.W. Erdman Jr., 2020. Synthetic, compared to natural alpha-tocopherol, downregulates myelination genes in cerebella of adolescent alpha-tocopherol transport protein-null mice. J. Nutrition. 150:1031-40 Doi.org/10.1093/jn/nxz330.
- Type:
Journal Articles
Status:
Published
Year Published:
2021
Citation:
Ranard, K.M., Kuchan, M.J., Juraska, J.M. and J.W. Erdman Jr. 2021. Natural and synthetic alpha-tocopherol modulate the neuroinflammatory response in the spinal cord of adult Ttpa-null mice. Current Developments in Nutrition. doi:10.1093/cdn/nzab008.
- Type:
Journal Articles
Status:
Published
Year Published:
2020
Citation:
Ranard, K.M., M.J. Kuchan and J.W. Erdman Jr. 2020. Breeder diet strategies for generating Ttpa-null and wild type mice with marginal vitamin E status to assess neurological outcomes. Current Developments in Nutrition. doi.org/10.1093/cdn/nzaa155.
- Type:
Journal Articles
Status:
Published
Year Published:
2018
Citation:
Ranard, K.M. and J.W. Erdman Jr. 2018. Effects of dietary RRR vs. all-racemic alpha-tocopherol on health outcomes. Nutrition Reviews (2018) 76(3):141-153. doi:10.1093/nutrit/nux067.
|
Progress 10/01/19 to 09/30/20
Outputs
Target Audience:The target audience is the consumer. To reach the consumers, we will present our results at professional meetings where public health professionals attend. We will alsopublish our findings in well-read journals. Public health professionals and public policy groups make recommendations to consumers. If we are successful, it will become clearer to the American population that they are not consuming sufficient vitamin E from vegetable oils. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest?We now have published three manuscripts from this work, oneother has been submitted and another is nearly ready for submission. Most of this work has been presented several times at national meetings in poster or oral formats. What do you plan to do during the next reporting period to accomplish the goals?We have just initiating breeding mice for a new study with the objective of assessing how different dietary levels of natural α-T affect markers of oxidative stress following LPS treatment in adult Ttpa-/- mice.
Impacts
What was accomplished under these goals?
Study 1: Biological effects of RRR-α-tocopherol, all-rac α-tocopherol, and γ-tocopherol This study was completed in 2019. Study 2: In vivo bio-distribution of 13C a-tocopherol in marginally vitamin E deficient mice.Natural (RRR-) αT is more bioactive than synthetic (all racemic, all rac-) αT, but little is known about the tissue kinetics of the two αT sources. We sought to compare time-course bioaccumulation of natural vs. synthetic αT in tissues of young, marginally vitamin E-deficient mice using 13C-(RRR-) αT and 13C-all rac-αT tracers. To measure αT tissue depletion over time, three-week old male wild-type mice were fed a vitamin E-deficient diet for 0, 1, 2, or 3 weeks (n=5/time point) (Experiment 1). At each time point, tissue αT levels were analyzed by a high-performance liquid chromatography-photodiode array detector (HPLC-PDA). Following a two-week αT-depletion period, established from Experiment 1, mice were administered a single oral dose of 0.5 mg of 13C-RRR-αT or 13C-all rac-αT. At 12 hours, 1, 2, and 4 days post dose, plasma and multiple tissues were collected (n=3/time point). αT was quantified, and 13C-αT tissue enrichment was determined my mass spectrometry. Feeding a vitamin E-deficient diet for up to threeweeks decreased total αT concentrations in all analyzed tissues, except the brain which maintained its αT level. Both sources of 13C-αT reached maximum serum levels at 12 hourspost dose. At 1 day post dose, 13C-RRR-αT levels were significantly higher than 13C-all rac-αT in serum, heart, spleen, and adipose tissue. In brain, both sources of 13C-αT plateaued at 1 day post dose, and 13C-RRR-αT concentrations were significantly higher than 13C-all rac-αT at 1 and 2 days post dose. At 4 days post dose, 13C-αT levels were similar between the two sources in all examined tissues. Overall, αT bioaccumulation over time varied substantially depending on αT source and tissue type. . Study 3: Effects of RRR- vs. all-rac α-T on the nervous system in adolescent and adult Ttpa-/- mice Humans with vitamin E (α-T) deficiency have neurological disorders, such as cerebellar ataxia. Similarly, α-tocopherol transfer protein knockout (Ttpa−/−) mice have low α-T levels and develop neurological symptoms. The structural and behavioral manifestations of vitamin E deficiency are likely preceded by abnormalities in the transcriptome, but it is unknown how early these changes occur. Additionally, RRR- (natural) α-T is more biopotent than all-rac (synthetic) α-T, and they may differentially affect gene expression. Therefore, we assessed the effects of dietary α-T stereoisomer composition and dose on tissue α-T accumulation and cerebellar gene expression in adolescent and adult α-T transfer protein-null (Ttpa-/-) mice. An adolescent mouse study where weaning, male Ttpa-/- mice were fed either vitamin E-deficient diet (VED), natural α-T-supplemented diet (NAT), synthetic α-T-supplemented diet (SYN), or high synthetic α-T-supplemented diet (HYSN) for seven weeks was completed and the work published. An adult Ttpa-/- mouse study used the same α-T diets as the adolescent mouse study to maximize comparisons between life stages. For the adult study, weanling mice were fed their respective diets until tenmonths of age. We conducted analyses on both the spinal cord and cerebellum, as α-T-deficiency pathologies have been detected in these two tissues. Spinal cords of VED-fed mice had increased expression of neuro-inflammatory genes, such as Tnf and Ccl2. Both α-T sources normalized this outcome in the spinal cord. Cerebellar pathology was not evident in our tenmonth old Ttpa-/- mice; these histological aberrations may only occur during late adulthood. The spinal cord appeared to be particularly sensitive to α-T status, and these molecular findings aligned with the known morphological and neurobehavioral deficits that accompany α-T deficiency
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2020
Citation:
Ranard, K.M., M.J. Kuchan, J.M. Juraska, R. Bruno and J.W. Erdman Jr. 2020. Synthetic, compared to natural alpha-tocopherol, downregulates myelination genes in cerebella of adolescent alpha-tocopherol transport protein-null mice. J. Nutrition. 150:1031-40 Doi.org/10.1093/jn/nxz330.
- Type:
Journal Articles
Status:
Published
Year Published:
2020
Citation:
Ranard, K.M., M.J. Kuchan and J.W. Erdman Jr. 2020. Breeder diet strategies for generating Ttpa-null and wild type mice with marginal vitamin E status to assess neurological outcomes. Current Developments in Nutrition doi.org/10.1093/cdn/nzaa155.
|
Progress 10/01/18 to 09/30/19
Outputs
Target Audience:The primary target audience is the consumer. To reach consumers, we will present our results at professional meetings where public health professionals attend and publish our findings in well-read journals. Public health professionals and public policy groups make recommendations to consumers. If we are successful, it will become clearer to the American population that they are not consuming sufficient vitamin E from vegetable oils. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest?We have published one paper and submitted a second paper for publication in the current reporting period. We have also presented several posters at national nutrition meetings. We published papers previously as noted in prior progress reports. What do you plan to do during the next reporting period to accomplish the goals?We are currently conducting a study comparing the effects of dietary natural vs. synthetic α-T in the brain and spinal cord using adult Ttpa−/− mice (tenmonths old). Key endpoints will focus on myelination in order to complement and expand on the results from our previous study. In addition, we will carry out more work looking at13-C alpha tocopherol biodistribution in mice with marginal vitamin E status.
Impacts
What was accomplished under these goals?
Study 1: Biological effects of RRR-α-tocopherol, all-rac α-tocopherol, and γ-tocopherol Of the antioxidant vitamin E isoforms, α-tocopherol (α-T) and γ-tocopherol (γ-T) are the most abundant in the human diet, and α-T is consumed from both natural and synthetic sources. α-T and γ-T may differentially impact inflammation and influence cardiovascular outcomes, in part by modulating gene expression. The goal of these studies was to compare the effects of RRR-α-tocopherol (natural α-T), all-rac α-tocopherol (synthetic α-T), and γ-T on gene expression in two human aortic cell lines. Specifically, human aortic smooth muscle cells and endothelial cells were either: (1) Treated with 25 μM tocopherols alone;or (2) Pretreated with tocopherols prior to a pro-inflammatory cytokine (tumor necrosis factor-alpha, TNF-α) stimulation. We found that tocopherol treatments alone did not significantly modulate the expression of genes in unstimulated HASMC or HAEC. TNF-α stimulation significantly upregulated genes involved with apoptosis and stress response in both cell lines. Pretreating cells with tocopherols did not normalize the gene expression changes induced by TNF-α. However, α-T pretreatments, but not γ-T pretreatments, attenuated TNF expression in both HASMC and HAEC. Study 2: In vivo bio-distribution of 13C a-tocopherol in marginally vitamin E deficient mice To prepare for a 13-C a-tocopherol pharmacokinetics study, three-week old weanling mice were fed α-T-stripped diet for either one, two, or threeweeks during their rapid growth phase. At each time-point tissue, α-T concentrations were analyzed. Other than brain where α-T concentrations were maintained, most other tissues had decreased α-T over time. At threeweeks, serumand liverα-T declined to 27 and 7%, respectively, while heart, spleen, lungs, kidney and adrenal glands all declined between 33 - 41% compared to baseline. These findings will be utilized to inform the design of the next study. Study 3: Effects of RRR- vs. all-rac α-T on the nervous system in adolescent and adult Ttpa-/- mice Humans with vitamin E (α-T) deficiency have neurological disorders, such as cerebellar ataxia. Similarly, α-tocopherol transfer protein knockout (Ttpa−/−) mice have low α-T levels and develop neurological symptoms. The structural and behavioral manifestations of vitamin E deficiency are likely preceded by abnormalities in the transcriptome, but it is unknown how early these changes occur. Additionally, RRR- (natural) α-T is more biopotent than all-rac (synthetic) α-T, and they may differentially affect gene expression. Therefore, we assessed the effects of dietary α-T stereoisomer composition and dose on tissue α-T accumulation and cerebellar gene expression in adolescent α-T transfer protein-null (Ttpa-/-) mice. From weaning (three weeks) until sevenweeks of age, male Ttpa-/- mice were fed either vitamin E-deficient diet (VED), natural α-T-supplemented diet (NAT), synthetic α-T-supplemented diet (SYN), or high synthetic α-T-supplemented diet (HYSN). Male Ttpa+/+ littermates fed a control diet (CON) served as the reference group. Tissue α-T concentrations and brain α-T stereoisomer profiles were analyzed for all groups. RNA-sequencing was performed on cerebella of the Ttpa-/- groups. We found that Ttpa-/- mice fed VED had undetectable brain α-T levels. The NAT, SYN, and HSYN diets increased brain total α-T accumulation, but concentrations were significantly lower than in Ttpa+/+ mice fed CON diet (P < 0.001). RRR α-T was the predominant stereoisomer in brains of Ttpa+/+ mice (~40%) and Ttpa-/- mice fed NAT (~94%). α-T stereoisomers accumulated equally in brains of Ttpa-/- mice fed SYN and HSYN (2R: ~53%; 2S: ~47%). Very few genes of the 16,774 measured were differentially expressed between diet groups. However, compared to the NAT diet, HSYN significantly downregulated twentymyelination genes in the cerebellum, including two key transcription factors (Sox10 and Myrf) and downstream target genes (FDR < 0.05). Therefore, high-dose synthetic α-T compared to natural α-T alters myelin gene expression in the adolescent mouse brain. This could lead to morphological and functional abnormalities later in life.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2019
Citation:
Ranard, K.M., Kuchan, M.J. and Erdman, J.W. 2019. a-Tocopherol, but not g-tocopherol, attenuates the expression of selective TNF-a-induced genes in primary human aortic cell lines. Lipids. (2019) 54:289-299. doi:10.1002/lipd.12149.
|
Progress 10/01/17 to 09/30/18
Outputs
Target Audience:The primary target audience is the consumer. To reach the consumers, we will present our results at professional meetings where public health professionals attend and publish our findings in well-read journals. Public health professionals and public policy groups make recommendations to consumers. If we are successful, it will become clearer to the American population that they are not consuming sufficient natural vitamin E from vegetable oils. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest?We have submitted one paper for publication and have presented several posters at national nutrition meetings. In addition, we have publishedtwo papers in 2018as reported in this progress report. What do you plan to do during the next reporting period to accomplish the goals?We will devote most of our energy toStudy 2 in the next reporting period.
Impacts
What was accomplished under these goals?
Study 1: In vitro bio-distribution and biological impact of RRR and all rac α-tocopherol. Of the antioxidant vitamin E isoforms, α-tocopherol (αT) and γ-tocopherol (γT) are the most abundant in the human diet, and αT is consumed from both natural and synthetic sources. αT and γT may differentially impact inflammation and influence cardiovascular outcomes, in part by modulating gene expression. The goal of this study was to compare the effects of natural αT, synthetic αT, and γT on gene expression in two human cell lines. Human aortic smooth muscle cells (HASMC) and endothelial cells (HAEC) were either: a) treated with physiologically relevant doses of tocopherols alone, or b) pre-treated with tocopherols prior to a pro-inflammatory cytokine (TNF-α) stimulation. The expression of atherosclerosis-related genes was measured using RT2 Profiler PCR arrays. Tocopherol treatments alone did not substantially modulate the expression of genes in unstimulated HASMC or HAEC. TNF-α stimulation significantly upregulated genes involved with apoptosis and stress response in both cell lines. Pre-treating cells with tocopherols did not normalize the gene expression changes induced by TNF-α. However, both natural and synthetic αT pre-treatments, but not γT pre-treatments, attenuated the effect of TNF-α on TNF and BCL2A1 expression in HASMC. These findings suggest that under stimulated conditions, αT modestly modulates the expression of selected genes and that αT may be more anti-inflammatory than γT. Study 2: In vivo bio-distribution of 13C a-tocopherol in marginally vitamin E deficient mice. No work was accomplished under this objective. Study 3: Effects of RRR- and all-racemic α-tocopherol on the neurological network in young and aging adult Ttpa-/- mice. Humans with vitamin E deficiency develop neurological disorders, including cerebellar ataxia. Similarly, α-tocopherol transfer protein knockout (Ttpa−/−) mice are vitamin E deficient and exhibit neurodegeneration with age. The structural and behavioral manifestations of vitamin E deficiency are likely preceded by abnormalities in the transcriptome, but it is unknown how early these changes occur. Aberrations during brain development could have lifelong implications. The objective of this study was to determine how vitamin Erestriction during early-life affects the expression of pre-selected neurogenesis-related genes in the cerebellum and cerebral cortex in Ttpa−/− mice. Brain tissues fromthree week old female wild-type, Ttpa+/+ (n=9) and Ttpa−/− (n=10) mice were used for the study. Vitamin E concentrations were measured in homogenized brain samples via HPLC-PDA to determine αT status. The expression of genes essential for brain development (Rora, Shh), myelination (Plp1, Cntnap1, Mbp, Mobp, Nr1h3), synaptic function (Cplx1, Cplx2, Vamp2, Necab1, Prkcg), and αT cellular uptake (Scarb1) were measured in the cerebellum and cerebral cortex via real-time qPCR. αT levels were significantly decreased in brains of Ttpa−/− mice compared to Ttpa+/+ mice (P<0.001), confirming their low αT status. Rora, Shh, Cntnap1, and Mbp were significantly upregulated (P<0.05) in both the cerebellum and cerebral cortex of juvenile Ttpa−/− mice, while several genes were only upregulated in one brain region (Plp1 in the cerebellum, Mobp in the cerebral cortex). Necab1 and Scarb1 were significantly downregulated in the cerebellum of Ttpa−/− mice (P<0.05). It was concluded thatvitamin Erestriction during infancy alters the expression of neurogenesis-related genes. These findings support a role for vitamin E in brain development and may partially explain the neurological symptoms observed in adulthood.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2018
Citation:
Ranard, K. and J.W. Erdman Jr. 2018. Impact of RRR vs. all-racemic alpha-tocopherol on health outcomes: Pieces of the puzzle. Nutrition Reviews 76(3):141-153.
- Type:
Journal Articles
Status:
Published
Year Published:
2018
Citation:
Ranard, K.M., S. Jeon, E.S. Mohn, J.C. Griffiths, E.J. Johnson and J.W. Erdman Jr. 2017. Dietary guidance for lutein Considerations for intake recommendations is scientifically supported. European J. Nutrition. 56 (Suppl 3):S37-42. https://doi.org/10.1007/s00394-017-1580-2.
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Progress 10/01/16 to 09/30/17
Outputs
Target Audience:The primary target audience is the consumer. To reach consumers, we will present our results at professional meetings where public health professionals attend and publish our findings in well-read journals. Public health professionals and public policy groups make recommendations to consumers; if we are successful, it will become clearer to the American peoplethat they are not consuming sufficient natural vitamin E from vegetable oils. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Several Ph.D. students have received additional laboratory experience carrying out these studies. How have the results been disseminated to communities of interest?
Nothing Reported
What do you plan to do during the next reporting period to accomplish the goals?We will be carrying out additional work on all three proposed studies. We will be presenting results at national meetings and preparing publications.
Impacts
What was accomplished under these goals?
Study 1 progress: Using primary human vascular aortic smooth muscle cells, we compared the impact of three tocopherol forms (RRR α-tocopherol, all-racemic α-tocopherol, and γ-tocopherol) on cell uptake and the expression of atherosclerosis-related genes. Using a cytotoxicity assay, we confirmed that the tocopherol doses used in the experiments (25µM) did not cause cell toxicity. Cell uptake studies showed that the tocopherols were taken up into cells at a linear rate. For the gene expression experiments, cells were treated with one of the three tocopherols, and then half of the cell plates were stimulated with a pro-inflammatory cytokine (TNF-α). Using a pre-designed RT-qPCR array, we showed that the tocopherol treatments down-regulated genes encoding cell adhesion molecules. These molecules are important for the inflammatory response and cell recruitment during atherosclerosis. However, we were unable to replicate these results using self-designed primers and RT-qPCR. Currently, we are growing primary human aortic endothelial cells to be used for gene expression experiments. Multiple studies usingendothelial cell lines for similar tocopherol experiments have shown significant changes in gene expression. We expect that our studies will strengthen previous findings. Study 2 progress: This study has not yet been initiated. Study 3 progress: We have bred TTP-/- sires with C57BL/6J dams to obtain TTP+/- offspring. We also successfully paired these TTP+/- offspring to produce TTP+/+ (wild-type) and TTP-/- (TTP knockout) mice, which will be used in the in vivo α-tocopherol brain studies. We have conducted preliminary work to ensure that the brain tissues of study animals are depleted of α-tocopherol before being assigned their treatment diets. We achieved this by switching the dam's diet to a vitamin E-stripped diet during gestation and lactation.
Publications
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