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Grieve E, Mamun AA, de Roos B, Barman BK, Ara G, Roos N, Pounds A, Sneddon AA, Murray F, Ahmed T, Little DC. Adolescent girls in aquaculture ecozones at risk of nutrient deficiency in Bangladesh development and validation of an integrated metric. BMC Public Health 2023; 23:405. [PMID: 36855076 PMCID: PMC9972605 DOI: 10.1186/s12889-023-15175-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 01/31/2023] [Indexed: 03/02/2023] Open
Abstract
BACKGROUND This study developed and validated an integrated metric that enhances understanding of linkages between agro-ecological and socio-economic factors that are important for explaining nutritional wellbeing in relation to fish consumption; especially among adolescent girls who are at risk of nutritional deficiency in Bangladesh. Currently, there is no metric that takes account of environmental, cultural and economic contexts when considering fish consumption and dietary health from a policy perspective. METHODS The study was designed as a bi-seasonal survey, repeated in the same population of adolescent girls recruited during the dry and wet seasons. Sampling was stratified by five settings (four aqua-agroecological zones and one processing plant community), with 60 girls recruited in each. Associations between candidate predictors (salinity, diet diversity, religion, socio-economic status and women's autonomy score) and dependent variables representing nutritional outcomes (anthropometry, omega-3 index and micronutrient levels) were explored in multivariable regressions. The fitted model with its predictors was validated, and a risk score derived from responses to a few short questions on religion, salinity zone, female autonomy, diet diversity and tilapia consumption. RESULTS The omega-3 index showed the clearest distinction between seasons, by salinity and religion. Higher female autonomy, religion (being Hindu rather than Muslim), geographical location (living in a high or mid-saline area), and a higher dietary diversity were the strongest predictors of whole blood omega-3 index. The c-index for the prognostic model was 0.83 and 0.76 in the wet and dry season respectively, indicating good predictive accuracy. There appeared to be a clear trend in risk scores differentiating between those 'chronically at risk' and those 'never at risk'. CONCLUSIONS Observational data on different aquaculture-ecozones defined by salinity enabled us to establish linkages between seasonal fish intake, religion, diet diversity, female autonomy and nutritional wellbeing. The purpose of the metric is to reveal these specific linkages in practice. This tool should improve targeting of timely, preventative and cost-effective nutritional interventions to adolescent girls most at-risk from low omega-3 levels in communities where seafood is produced.
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Affiliation(s)
- Eleanor Grieve
- 1 Lilybank Gardens, Institute of Health and Wellbeing, University of Glasgow, Glasgow, G12 8RZ, UK.
| | - Abdullah-Al Mamun
- Department of Fisheries and Marine Science, Noakhali Science and Technology University, University Road, Noakhali, 3814, Bangladesh
| | - Baukje de Roos
- The Rowett Institute, University of Aberdeen, Ashgrove Road W, Aberdeen, AB25 2ZD, UK
| | - Benoy K Barman
- WorldFish, Bangladesh and South Asia, House 355/A Rd 114, Dhaka, 1212, Bangladesh
| | - Gulshan Ara
- Nutrition and Clinical Services Division, International Centre for Diarrhoeal Disease Research, GPO Box 128, Dhaka, 1000, Bangladesh
| | - Nanna Roos
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Nørre Allé 51, 2200, Copenhagen, Denmark
| | - Alexandra Pounds
- Institute of Aquaculture, University of Stirling, Stirling, FK9 4LA, UK
| | - Alan A Sneddon
- The Rowett Institute, University of Aberdeen, Ashgrove Road W, Aberdeen, AB25 2ZD, UK
| | - Francis Murray
- Institute of Aquaculture, University of Stirling, Stirling, FK9 4LA, UK
| | - Tahmeed Ahmed
- Nutrition and Clinical Services Division, International Centre for Diarrhoeal Disease Research, GPO Box 128, Dhaka, 1000, Bangladesh
| | - David C Little
- Institute of Aquaculture, University of Stirling, Stirling, FK9 4LA, UK
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de Roos B, Roos N, Ara G, Ahmed T, Mamun A, Sneddon AA, Murray F, Grieve E, Little DC. Linkages of agroecosystems producing farmed seafood on food security, nutritional status and adolescent health in Bangladesh. Matern Child Nutr 2020; 16 Suppl 3:e13017. [PMID: 33347719 PMCID: PMC7752128 DOI: 10.1111/mcn.13017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 03/29/2020] [Accepted: 04/06/2020] [Indexed: 11/29/2022]
Abstract
This narrative review aims to provide an interdisciplinary perspective on actors that link global aquatic food production systems with fish consumption and nutritional status, with a special focus on adolescent girls in Bangladesh. The writing of this narrative perspective was undertaken within the framework of the Aquatic Food for Health and Nutrition (AQN) project that aimed to develop a metric for assessing the impacts on nutrition and health of agroecosystems producing farmed seafood. Previous studies evaluating links between agricultural ecosystems, aquaculture, food security and human health have systemically ignored the importance of diet and nutrition. Such studies have also ignored the importance of local communities, cultural norms and household composition and behaviours to identify vulnerable groups such as adolescent girls. This narrative review presents our current understanding of the relationships between aquaculture, fish production and consumption patterns, food security, optimal nutrition and health. It also highlights the importance of research into aquaculture food systems, linking aquatic food production systems with nutritional status, health and socioeconomic prosperity, which would help to develop more integrated and relevant food policies.
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Affiliation(s)
| | - Nanna Roos
- Department of Nutrition, Exercise and SportsUniversity of CopenhagenCopenhagenDenmark
| | - Gulshan Ara
- Nutrition and Clinical Services DivisionInternational Centre for Diarrhoeal Disease ResearchDhakaBangladesh
| | - Tahmeed Ahmed
- Nutrition and Clinical Services DivisionInternational Centre for Diarrhoeal Disease ResearchDhakaBangladesh
| | - Abdullah‐Al Mamun
- Department of Fisheries and Marine ScienceNoakhali Science and Technology UniversityNoakhaliBangladesh
| | | | - Francis Murray
- Institute of AquacultureUniversity of StirlingStirlingUK
| | - Eleanor Grieve
- Institute of Health and WellbeingUniversity of GlasgowGlasglowUK
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de Roos B, Wood S, Bremner D, Bashir S, Betancor MB, Fraser WD, Duthie SJ, Horgan GW, Sneddon AA. The nutritional and cardiovascular health benefits of rapeseed oil-fed farmed salmon in humans are not decreased compared with those of traditionally farmed salmon: a randomized controlled trial. Eur J Nutr 2020; 60:2063-2075. [PMID: 33015732 PMCID: PMC8137615 DOI: 10.1007/s00394-020-02396-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 09/23/2020] [Indexed: 11/30/2022]
Abstract
PURPOSE Farmed fish are increasingly raised on feeds containing vegetable oils, which affects their composition and possibly health properties. We investigated the effects of consuming farmed salmon, raised on different feeding regimes, on nutrient status and health outcomes in healthy subjects. METHODS Salmon were grown on feeds containing mainly fish oil (FO) or rapeseed oil (RO), resulting in an eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) content of fillets of 2.1 or 0.9 g/100 g, respectively. In a randomized parallel controlled trial, 51 healthy subjects were allocated to consume 2 portions/week of FO salmon (n = 17), RO salmon (n = 17) or no additional salmon (Control, n = 17) as part of their habitual diet, for 18 weeks. We collected blood at 0, 9 and 18 weeks to measure omega-3 index (O3I) in red blood cells, plasma markers of cardiovascular risk, serum 25(OH)-vitamin D3 (25(OH)D3) and plasma trace elements. RESULTS After 18 weeks, O3I was similarly increased in subjects consuming 2 portions/week of FO or RO salmon compared to control (both p < 0.05). Serum 25(OH)D3 was significantly higher, whereas plasma triacylglycerols were significantly lower in subjects consuming RO salmon compared to control (both p < 0.05). Heart rate was significantly lower in subjects consuming FO salmon after 9 weeks, compared to control (p < 0.01). Salmon consumption did not affect other markers. CONCLUSION Consuming two portions/week of salmon raised on rapeseed oil rather than fish oil increased the O3I and vitamin D status, and decreased plasma triacylglycerols. These outcomes endorse opportunities for developing more sustainable feeds within aquaculture food systems. CLINICAL TRIAL REGISTRY This trial was registered at clinicaltrials.gov as NCT01916434.
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Affiliation(s)
- Baukje de Roos
- Rowett Institute, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK.
| | - Sharon Wood
- Rowett Institute, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK
| | - David Bremner
- Rowett Institute, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK
| | - Shabina Bashir
- Rowett Institute, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK
| | | | | | - Susan J Duthie
- Rowett Institute, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK.,School of Pharmacy and Life Sciences, Robert Gordon University, Aberdeen, UK
| | | | - Alan A Sneddon
- Rowett Institute, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK
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Brown I, Lee J, Sneddon AA, Cascio MG, Pertwee RG, Wahle KWJ, Rotondo D, Heys SD. Anticancer effects of n-3 EPA and DHA and their endocannabinoid derivatives on breast cancer cell growth and invasion. Prostaglandins Leukot Essent Fatty Acids 2020; 156:102024. [PMID: 31679810 DOI: 10.1016/j.plefa.2019.102024] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 10/11/2019] [Accepted: 10/15/2019] [Indexed: 12/16/2022]
Abstract
The anticancer effects of the omega-3 long chain polyunsaturated fatty acids (LCPUFA), EPA and DHA may be due, at least in part, to conversion to their respective endocannabinoid derivatives, eicosapentaenoyl-ethanolamine (EPEA) and docosahexaenoyl-ethanolamine (DHEA). Here, the effects of EPEA and DHEA and their parent compounds, EPA and DHA, on breast cancer (BC) cell function was examined. EPEA and DHEA exhibited greater anti-cancer effects than EPA and DHA in two BC cells (MCF-7 and MDA-MB-231) whilst displaying no effect in non-malignant breast cells (MCF-10a). Both BC lines expressed CB1/2 receptors that were responsible, at least partly, for the observed anti-proliferative effects of the omega-3 endocannabinoids as determined by receptor antagonism studies. Additionally, major signalling mechanisms elicited by these CB ligands included altered phosphorylation of p38-MAPK, JNK, and ERK proteins. Both LCPUFAs and their endocannabinoids attenuated the expression of signal proteins in BC cells, albeit to different extents depending on cell type and lipid effectors. These signal proteins are implicated in apoptosis and attenuation of BC cell migration and invasiveness. Furthermore, only DHA reduced in vitro MDA-MB-231 migration whereas both LCPUFAs and their endocannabinoids significantly inhibited invasiveness. This finding was consistent with reduced integrin β3 expression observed with all treatments and reduced MMP-1 and VEGF with DHA treatment. Attenuation of cell viability, migration and invasion of malignant cells indicates a potential adjunct nutritional therapeutic use of these LCPUFAs and/or their endocannabinoids in treatment of breast cancer.
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Affiliation(s)
- Iain Brown
- Division of Applied Medicine, School of Medicine and Dentistry, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK.
| | - Jisun Lee
- Division of Applied Medicine, School of Medicine and Dentistry, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK.
| | - Alan A Sneddon
- Rowett Institute, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK.
| | - Maria G Cascio
- Translational Neuroscience Research Programme, School of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK.
| | - Roger G Pertwee
- Translational Neuroscience Research Programme, School of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK.
| | - Klaus W J Wahle
- Division of Applied Medicine, School of Medicine and Dentistry, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK; Institute of Pharmacy and Biomedical Sciences, Strathclyde University, Glasgow, G4 0RE, UK.
| | - Dino Rotondo
- Institute of Pharmacy and Biomedical Sciences, Strathclyde University, Glasgow, G4 0RE, UK.
| | - Steven D Heys
- Division of Applied Medicine, School of Medicine and Dentistry, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK.
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Denholm SJ, Sneddon AA, McNeilly TN, Bashir S, Mitchell MC, Wall E. Phenotypic and genetic analysis of milk and serum element concentrations in dairy cows. J Dairy Sci 2019; 102:11180-11192. [PMID: 31587908 DOI: 10.3168/jds.2019-16960] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 08/20/2019] [Indexed: 11/19/2022]
Abstract
Enhancing micronutrient (i.e., mineral and vitamin) concentrations within milk and serum from dairy cows is important for both the health of the cow and the nutritive value of the milk for human consumption. However, a good understanding of the genetics underlying the micronutrient content in dairy cattle is needed to facilitate such enhancements through feeding or breeding practices. In this study, milk (n = 950) and serum (n = 766) samples were collected from Holstein-Friesian dairy cows (n = 479) on 19 occasions over a 59-mo period and analyzed for concentrations of important elements. Additionally, a subset of 256 milk samples was analyzed for concentrations of vitamin B12. Cows belonged to 2 genetic lines (average and highest genetic merit for milk fat plus protein yield) and were assigned to 1 of 2 diets based on either a by-product or homegrown ration. Univariate models accounting for repeated records were used to analyze element and vitamin B12 data and investigate the effect of genotype and feeding system as well as derive estimates of variance components and genetic parameters. Bivariate models were used to study correlations both within and between milk and serum. Only concentrations of Hg in milk were seen to be affected by genotype, with higher concentrations in cows with high genetic merit. In contrast, element concentrations were influenced by feeding system such that cows fed the homegrown diet had increased milk concentrations of Ca, Cu, I, Mn, Mo, P, and K and increased serum concentrations of Cd, Cu, Fe, Mo, and V. Cows on the by-product diet had increased milk concentrations of Mg, Se, and Na and increased serum concentrations of P and Se. Heritability (h2) estimates were obtained for 6 milk and 4 serum elements, including Mg (h2milk = 0.30), K (h2serum = 0.18), Ca (h2milk = 0.20; h2serum = 0.12), Mn (h2milk = 0.14), Cu (h2serum = 0.22), Zn (h2milk = 0.24), Se (h2milk = 0.15; h2serum = 0.10), and Mo (h2milk = 0.19). Significant estimates of repeatability were observed in all milk and serum quantity elements (Na, Mg, P, K, and Ca) as well as 5 milk and 7 serum trace elements. Only K in milk and serum was found to have a significant positive genetic and phenotypic correlation (0.52 and 0.22, respectively). Significant phenotypic associations were noted between milk and serum Ca (0.17), Mo (0.19), and Na (-0.79). Additional multivariate analyses between measures within sample type (i.e., milk or serum) revealed significant positive associations, both phenotypic and genetic, between some of the elements. In milk, Se was genetically correlated with Ca (0.63), Mg (0.59), Mn (0.40), P (0.53), and Zn (0.52), whereas in serum, V showed strong genetic associations with Cd (0.71), Ca (0.53), Mn (0.63), Mo (0.57), P (0.42), K (0.45), and Hg (-0.44). These results provide evidence that element concentrations in milk and blood of dairy cows are significantly influenced by both diet and genetics and demonstrate the potential for genetic selection and dietary manipulation to alter nutrient concentration to improve both cow health and the healthfulness of milk for human consumption.
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Affiliation(s)
- Scott J Denholm
- Animal and Veterinary Sciences, Scotland's Rural College, Easter Bush, Midlothian, United Kingdom, EH25 9RG.
| | - Alan A Sneddon
- The Rowett Institute, University of Aberdeen, Aberdeen, United Kingdom, AB25 2ZD
| | - Tom N McNeilly
- Moredun Research Institute, Pentlands Science Park, Midlothian, United Kingdom, EH26 0PZ
| | - Shabina Bashir
- The Rowett Institute, University of Aberdeen, Aberdeen, United Kingdom, AB25 2ZD
| | - Mairi C Mitchell
- Moredun Research Institute, Pentlands Science Park, Midlothian, United Kingdom, EH26 0PZ
| | - Eileen Wall
- Animal and Veterinary Sciences, Scotland's Rural College, Easter Bush, Midlothian, United Kingdom, EH25 9RG
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Dyck KN, Bashir S, Horgan GW, Sneddon AA. Regular crabmeat consumers do not show increased urinary cadmium or beta-2-microglobulin levels compared to non-crabmeat consumers. J Trace Elem Med Biol 2019; 52:22-28. [PMID: 30732886 DOI: 10.1016/j.jtemb.2018.10.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 09/27/2018] [Accepted: 10/26/2018] [Indexed: 11/23/2022]
Abstract
Cadmium (Cd) is a toxic metal that can be relatively high in brown meat from crab and there is concern that it may accumulate in long-term crabmeat consumers posing a health risk. Sixteen healthy habitual crabmeat consumers and twenty five healthy non-crabmeat consumers were recruited through completion of a seafood frequency questionnaire. Whole blood and urine samples were analysed for Cd levels and urinary beta-2-microglobulin, an established marker of Cd-induced kidney toxicity, to determine levels in crabmeat consumers. Whole blood Cd levels were significantly elevated in the crabmeat-consuming group, whereas urinary levels of Cd and beta-2-microglobulin were not. Whole blood Cd levels can be both a short and long-term marker for Cd intake and levels might be expected to be elevated in the crabmeat consumers as crabmeat can contain Cd. However, crabmeat consumers did not show increases in a more established long-term marker of Cd (urinary Cd) and consistent with this, no change in a Cd-induced kidney toxicity marker. Consequently, in conclusion, compared to consumers who reported very little crabmeat consumption, healthy middle-aged consumers who regularly consume brown crabmeat products (an average of 447 g/week) for an average of 16 years showed no change in long-term Cd exposure or kidney toxicity.
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Affiliation(s)
- Karlee N Dyck
- The Rowett Institute, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK
| | - Shabina Bashir
- The Rowett Institute, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK
| | - Graham W Horgan
- Biomathematics and Statistics Scotland, Foresterhill, Aberdeen, AB25 2ZD, UK
| | - Alan A Sneddon
- The Rowett Institute, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK.
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Donadio JLS, Rogero MM, Guerra-Shinohara EM, Barbosa F, Desmarchelier C, Borel P, Sneddon AA, Hesketh JE, Cozzolino SMF. Genetic variants in selenoprotein genes modulate biomarkers of selenium status in response to Brazil nut supplementation (the SU.BRA.NUT study). Clin Nutr 2018; 38:539-548. [PMID: 29609868 DOI: 10.1016/j.clnu.2018.03.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 03/08/2018] [Accepted: 03/12/2018] [Indexed: 12/27/2022]
Abstract
BACKGROUND The beneficial effects of selenium (Se) to human health are exerted by selenoproteins, which can be quantified in blood and used as biomarkers of Se status. Different responses of Se biomarkers after supplementation with selenomethionine and sodium selenite have been observed and some of them could be due to genetic polymorphisms, mainly single nucleotide polymorphisms (SNPs). Brazil nuts are known to be the richest natural source of Se. OBJECTIVE Investigate how genetic variations in selenoprotein genes modulate biomarkers of Se status in response to Brazil nut supplementation. METHODS The SU.BRA.NUT study was a four month interventional trial which involved healthy volunteers of both genders, selected in University of Sao Paulo. The supplementation was done with one Brazil nut a day for 8 weeks, followed by 8 weeks of washout. Blood samples were collected at 5 time points: baseline, 4 and 8 weeks of supplementation and 4 and 8 weeks of washout for analysis of five biomarkers of Se status - erythrocyte GPx1 (Glutathione Peroxidase 1) activity, plasma GPx3 activity, plasma Se, erythrocyte Se, and plasma selenoprotein P. The gene expression of GPX1, SELENOP, SELENOF and SELENOS was done before and after 8 weeks of supplementation. The volunteers were genotyped for SNPs in GPX1 (rs1050450, rs3811699 and rs1800699), GPX4 (rs713041), SELENOP (rs3877899 and rs7579), SELENOF (rs5845) and SELENOS (rs34713741). RESULTS A total of 130 volunteers finished the protocol. The concentrations of four biomarkers of Se status increased significantly after 4 and 8 weeks of supplementation, being modulated by gender. In addition, erythrocyte GPx1 activity was associated with rs1050450, rs713041 and rs5845. Plasma Se was associated with rs7579 and selenoprotein P with plasma Se at baseline. Nut supplementation significantly increased GPX1 mRNA expression only in subjects with CC genotype at rs1050450. SELENOP mRNA expression was significantly lower in subjects with GG genotype at rs7579 before and after supplementation. CONCLUSION Genetic variations in GPX1 and SELENOP genes are associated with different responses of molecular and biochemical biomarkers of Se status after Brazil nut supplementation in healthy Brazilians. The SU.BRA.NUT study was registred at www.clinicaltrials.gov as NCT 03111355.
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Affiliation(s)
- Janaina L S Donadio
- Department of Food and Experimental Nutrition, Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil.
| | - Marcelo M Rogero
- Department of Nutrition, Faculty of Public Health, University of São Paulo, São Paulo, Brazil.
| | - Elvira M Guerra-Shinohara
- Department of Clinical and Toxicological Analysis, Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil.
| | - Fernando Barbosa
- Department of Clinical, Toxicological and Bromatological Analysis, Faculty of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil.
| | | | - Patrick Borel
- C2VN, Aix-Marseille Univ, INRA, INSERM, Marseille, France.
| | - Alan A Sneddon
- The Rowett Institute, University of Aberdeen, Aberdeen, UK.
| | - John E Hesketh
- Institute for Cell and Molecular Biosciences, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK.
| | - Silvia M F Cozzolino
- Department of Food and Experimental Nutrition, Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil.
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Zhang X, McGeoch SC, Johnstone AM, Holtrop G, Sneddon AA, MacRury SM, Megson IL, Pearson DWM, Abraham P, De Roos B, Lobley GE, O'Kennedy N. Platelet-derived microparticle count and surface molecule expression differ between subjects with and without type 2 diabetes, independently of obesity status. J Thromb Thrombolysis 2015; 37:455-63. [PMID: 24097206 DOI: 10.1007/s11239-013-1000-2] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
This study investigated the impact of either type 2 diabetes or obesity, separately or in combination, on the absolute amounts of microparticles (MP) and the pathways by which these are associated with either condition. The concentrations of circulating MP derived from platelets (PMP), leukocytes (LMP) and monocytes (MMP), together with their specific activation markers, were compared in 30 subjects who were characterised across 4 cohorts as obese or type 2 diabetes. The subjects with type 2 diabetes had elevated concentrations of total PMP (P = 0.003), and PMP that were fibrinogen-positive (P = 0.04), tissue factor-positive (P < 0.001), P-selectin-positive (P = 0.03). Type 2 diabetes did not alter either total or activated LMP or MMP. Obesity per se did not impact on any MP measurement. Elevated concentrations of plasma PMP occurred in subjects with type 2 diabetes, whether they were obese or non-obese. In contrast, obesity in the absence of type 2 diabetes had no effect. The increased concentrations of specific marker-positive PMP in the subjects with diabetes might reflect potential pathways by which PMP may contribute to the pathogenesis of atherosclerosis and type 2 diabetes.
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Affiliation(s)
- Xuguang Zhang
- Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, UK,
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Crosley LK, Bashir S, Nicol F, Arthur JR, Hesketh JE, Sneddon AA. The single-nucleotide polymorphism (GPX4c718t) in the glutathione peroxidase 4 gene influences endothelial cell function: interaction with selenium and fatty acids. Mol Nutr Food Res 2013; 57:2185-94. [PMID: 23934705 PMCID: PMC4063342 DOI: 10.1002/mnfr.201300216] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 05/30/2013] [Accepted: 06/09/2013] [Indexed: 12/14/2022]
Abstract
SCOPE Selenium (Se) is incorporated into selenoproteins as selenocysteine, which requires structures in the 3'-untranslated region (3'-UTR) of selenoprotein mRNAs. The functional consequences of a single nucleotide polymorphism (SNP) within the 3'-UTR of the selenoprotein GPX4 gene (GPX4c718t) was assessed in human umbilical vein endothelial cells (HUVECs) and monocytes from human volunteers. METHODS AND RESULTS HUVEC and monocytes homozygous for the T- or C-variant of the GPX4c718t SNP were assessed for monocyte-endothelial cell adhesion, expression of VCAM-1 and sensitivity to oxidative challenge. Interaction of the SNP with Se and different PUFA and effects on selenoprotein expression were also investigated. HUVEC and monocytes homozygous for the T-variant showed elevated adhesion levels compared to cells of the C-variant. This effect was modified by Se and PUFA. HUVEC homozygous for the T-variant showed elevated levels of VCAM-1 protein in the presence of arachidonic acid, were more sensitive to oxidative challenge and showed Se-dependant changes in lipid peroxide levels and expression of additional selenoproteins. CONCLUSION These findings demonstrate functional effects of the GPX4c718t SNP in endothelial cells and may suggest that individuals with the TT genotype have impaired endothelial function and are at greater risk of vascular disease compared to individuals with the CC genotype.
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Affiliation(s)
- Lynne K Crosley
- Micronutrients Group, Lifelong Health Division, Rowett Institute of Nutrition and Health, University of AberdeenAberdeen, UK
| | - Shabina Bashir
- Micronutrients Group, Lifelong Health Division, Rowett Institute of Nutrition and Health, University of AberdeenAberdeen, UK
| | - Fergus Nicol
- Micronutrients Group, Lifelong Health Division, Rowett Institute of Nutrition and Health, University of AberdeenAberdeen, UK
| | - John R Arthur
- Micronutrients Group, Lifelong Health Division, Rowett Institute of Nutrition and Health, University of AberdeenAberdeen, UK
| | - John E Hesketh
- Institute for Cell and Molecular Biosciences and Human Nutrition Research Centre, The Medical School, Newcastle University, Tyne and WearUK
| | - Alan A Sneddon
- Micronutrients Group, Lifelong Health Division, Rowett Institute of Nutrition and Health, University of AberdeenAberdeen, UK
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Song HJ, Sneddon AA, Heys SD, Wahle KWJ. Regulation of fatty acid synthase (FAS) and apoptosis in estrogen-receptor positive and negative breast cancer cells by conjugated linoleic acids. Prostaglandins Leukot Essent Fatty Acids 2012; 87:197-203. [PMID: 23142364 DOI: 10.1016/j.plefa.2012.09.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Revised: 08/31/2012] [Accepted: 09/13/2012] [Indexed: 11/30/2022]
Abstract
BACKGROUND Conjugated linoleic acids (CLAs) are natural dairy food components that exhibit a unique body of potential health benefits in animals and man, including anti-cardiovascular disease and anti-cancer effects. Several studies have demonstrated that fatty acid synthase (FAS) levels (protein and mRNA) are over expressed in many carcinomas. Sterol regulatory element binding proteins (SREBPs) are transcription factors that regulate genes involved in lipid metabolism, including FAS. METHODS Breast cancer cell lines, MCF-7 and MDA-MB-231 were treated with CLAs to investigate the regulation of SREBP-1c and FAS expression. RESULTS In MDA-MB-231 cells, SREBP-1c and FAS were co-ordinately decreased by treatment with 25 μM CLA 9-11 and 10-12. In MCF-7 cells, the decrease in SREBP-1c and FAS expression was dependant on the concentration of CLA used. CONCLUSIONS The data suggest a differential effect of CLAs on SREBP-1c and FAS in estrogen receptor-positive (MCF-7) compared to estrogen receptor-negative (MDA-MB-231) breast cancer cells.
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Affiliation(s)
- H-J Song
- School of Life Science, The Robert Gordon University, Aberdeen, AB10 1JQ, UK
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11
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Abstract
Selenium (Se) is an important dietary micronutrient required for sustaining optimal health. Se is incorporated into proteins, many of which are antioxidants that protect the body against oxidative damage. As oxidative damage may contribute to the development of chronic diseases including cardiovascular disease (CVD), Se has been proposed to provide a protective role against this disease. Studies in vitro and in animals continue to provide increasing insight into the role of Se in promoting vascular health and ameliorating CVD. Se within vascular cells limits the adhesion together of such cells, an important early step in the development of vascular disease. Organic forms of Se may also afford vascular cells greater protection against oxidative challenge compared to inorganic forms. Nevertheless, current studies in humans investigating the relationship between Se and CVD have so far proved equivocal; larger randomized trials with different Se exposures in populations spanning the broad physiological Se status are needed to determine the criteria whereby Se may influence CVD outcome within different populations. Further studies are also needed to explore the effects of different Se species and the role of different selenoprotein genotypes in modifying Se status and their resultant impact on cardiovascular function.
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Gautrey H, Nicol F, Sneddon AA, Hall J, Hesketh J. A T/C polymorphism in the GPX4 3'UTR affects the selenoprotein expression pattern and cell viability in transfected Caco-2 cells. Biochim Biophys Acta 2011; 1810:584-91. [PMID: 21459128 PMCID: PMC3793862 DOI: 10.1016/j.bbagen.2011.03.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/09/2010] [Revised: 03/21/2011] [Accepted: 03/24/2011] [Indexed: 02/07/2023]
Abstract
BACKGROUND Synthesis of selenoproteins such as glutathione peroxidases (GPx) requires a specific tRNA and a stem-loop structure in the 3'untranslated region (3'UTR) of the mRNA. A common single nucleotide polymorphism occurs in the GPX4 gene in a region corresponding to the 3'UTR. METHODS The two variant 3'UTR sequences were linked to sequences from a selenoprotein reporter gene (iodothyronine deiodinase) and expressed in Caco-2 cells. Clones expressing comparable levels of deiodinase (assessed by real-time PCR) were selected and their response to tert-butyl hydroperoxide assessed by cell viability and measurement of reactive oxygen species. Selenoprotein expression was assessed by real-time PCR, enzyme activity and immunoassay. RESULTS When selenium supply was low, cells overexpressing the C variant 3'UTR showed lower viability after oxidative challenge, increased levels of reactive oxygen species and lower GPx activity and SelH mRNA expression compared to cells overexpressing the T variant. After selenium supplementation, cell viability and GPx4 expression were higher in the cells overexpressing the C variant. Expression of transgenes incorporating the T/C variant GPX4 (rs713041) sequences in Caco-2 cells leads to alterations in both cell viability after an oxidative challenge and selenoprotein expression. This suggests that the two variants compete differently in the selenoprotein hierarchy. GENERAL SIGNIFICANCE The data provide evidence that the T/C variant GPX4 (rs713041) alters the pattern of selenoprotein synthesis if selenium intake is low. Further work is required to assess the impact on disease susceptibility.
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Affiliation(s)
- Hannah Gautrey
- Institute for Cell and Molecular Biosciences, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
- Human Nutrition Research Centre, The Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
| | - Fergus Nicol
- Rowett Institute of Nutrition and Health, University of Aberdeen, Greenburn Rd, Bucksburn, Aberdeen, AB21 9SB, UK
| | - Alan A. Sneddon
- Rowett Institute of Nutrition and Health, University of Aberdeen, Greenburn Rd, Bucksburn, Aberdeen, AB21 9SB, UK
| | - Judith Hall
- Institute for Cell and Molecular Biosciences, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
| | - John Hesketh
- Institute for Cell and Molecular Biosciences, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
- Human Nutrition Research Centre, The Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
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13
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Sneddon AA, Rayner DV, Mitchell SE, Bashir S, Ha JH, Wahle KW, Morris AC, Williams LM. Dietary supplementation with conjugated linoleic acid plus n-3 polyunsaturated fatty acid increases food intake and brown adipose tissue in rats. Nutrients 2009; 1:178-96. [PMID: 22253977 PMCID: PMC3257602 DOI: 10.3390/nu1020178] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2009] [Accepted: 11/24/2009] [Indexed: 11/17/2022] Open
Abstract
The effect of supplementation with 1% conjugated linoleic acid and 1% n-3 long chain polyunsaturated fatty acids (CLA/n-3) was assessed in rats. Food intake increased with no difference in body weights. White adipose tissue weights were reduced whereas brown adipose tissue and uncoupling protein-1 expression were increased. Plasma adiponectin, triglyceride and cholesterol levels were reduced while leptin, ghrelin and liver weight and lipid content were unchanged. Hypothalamic gene expression measurements revealed increased expression of orexigenic and decreased expression of anorexigenic signals. Thus, CLA/n-3 increases food intake without affecting body weight potentially through increasing BAT size and up-regulating UCP-1 in rats.
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Affiliation(s)
- Alan A. Sneddon
- Vascular Health Programme, Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, AB21 9SB, UK; (A.A.S.); (S.B.)
| | - D. Vernon Rayner
- Obesity and Metabolic Health Programme, Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, AB21 9SB, UK; (D.V.R.); (S.E.M.); (J.-H.H.); (A.C.M.)
| | - Sharon E. Mitchell
- Obesity and Metabolic Health Programme, Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, AB21 9SB, UK; (D.V.R.); (S.E.M.); (J.-H.H.); (A.C.M.)
| | - Shabina Bashir
- Vascular Health Programme, Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, AB21 9SB, UK; (A.A.S.); (S.B.)
| | - Jung-Heun Ha
- Obesity and Metabolic Health Programme, Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, AB21 9SB, UK; (D.V.R.); (S.E.M.); (J.-H.H.); (A.C.M.)
| | - Klaus W. Wahle
- School of Medicine and Dentistry, Cancer Medicine Research Programme, University of Aberdeen, Aberdeen, AB25 2ZD, UK;
| | - Amanda C. Morris
- Obesity and Metabolic Health Programme, Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, AB21 9SB, UK; (D.V.R.); (S.E.M.); (J.-H.H.); (A.C.M.)
| | - Lynda M. Williams
- Obesity and Metabolic Health Programme, Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, AB21 9SB, UK; (D.V.R.); (S.E.M.); (J.-H.H.); (A.C.M.)
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14
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Sneddon AA, Tsofliou F, Fyfe CL, Matheson I, Jackson DM, Horgan G, Winzell MS, Wahle KWJ, Ahren B, Williams LM. Effect of a conjugated linoleic acid and omega-3 fatty acid mixture on body composition and adiponectin. Obesity (Silver Spring) 2008; 16:1019-24. [PMID: 18356842 DOI: 10.1038/oby.2008.41] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
This study aimed to determine the effect of supplementation with conjugated linoleic acids (CLAs) plus n-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFAs) on body composition, adiposity, and hormone levels in young and older, lean and obese men. Young (31.4+/-3.9 years) lean (BMI, 23.6+/-1.5 kg/m2; n=13) and obese (BMI, 32.4+/-1.9 kg/m2; n=12) and older (56.5+/-4.6 years) lean (BMI, 23.6+/-1.5 kg/m2; n=20) and obese (BMI, 32.0+/-1.6 kg/m2; n=14) men participated in a double-blind placebo-controlled, randomized crossover study. Subjects received either 6 g/day control fat or 3 g/day CLA (50:50 cis-9, trans-11:trans-10, cis-12) and 3 g/day n-3 LC-PUFA for 12 weeks with a 12-week wash-out period between crossovers. Body composition was assessed by dual-energy X-ray absorptiometry. Fasting adiponectin, leptin, glucose, and insulin concentrations were measured and insulin resistance estimated by homeostasis model assessment for insulin resistance (HOMA-IR). In the younger obese subjects, CLA plus n-3 LC-PUFA supplementation compared with control fat did not result in increased abdominal fat and raised both fat-free mass (2.4%) and adiponectin levels (12%). CLA plus n-3 LC-PUFA showed no significant effects on HOMA-IR in any group but did increase fasting glucose in older obese subjects. In summary, supplementation with CLA plus n-3 LC-PUFA prevents increased abdominal fat mass and raises fat-free mass and adiponectin levels in younger obese individuals without deleteriously affecting insulin sensitivity, whereas these parameters in young and older lean and older obese individuals were unaffected, apart from increased fasting glucose in older obese men.
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Affiliation(s)
- Alan A Sneddon
- Vascular Health Division, Rowett Research Institute, Aberdeen, UK.
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15
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Goua M, Mulgrew S, Frank J, Rees D, Sneddon AA, Wahle KWJ. Regulation of adhesion molecule expression in human endothelial and smooth muscle cells by omega-3 fatty acids and conjugated linoleic acids: involvement of the transcription factor NF-kappaB? Prostaglandins Leukot Essent Fatty Acids 2008; 78:33-43. [PMID: 18036803 DOI: 10.1016/j.plefa.2007.10.004] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2007] [Revised: 10/12/2007] [Accepted: 10/17/2007] [Indexed: 10/22/2022]
Abstract
We previously showed conjugated linoleic acids (CLA) inhibited TNF-alpha-induced monocyte (THP-1) adhesion to human umbilical vein endothelial cells (HUVEC) in vitro which involved an increase in platelet activating factor (PAF). Here we show adhesion molecule (ADM) regulation by fatty acids and the differing role of nuclear factor kappa B (NF-kappaB) activation in HUVEC and vascular smooth muscle cells (vSMC). CLA and omega-3 long-chain polyunsaturated fatty acids (PUFA) (FA) reduced TNF-alpha-induced expression of ADMs (intercellular adhesion molecule-1 (ICAM-1); vascular cell adhesion molecule-1 (VCAM-1) but not E-selectin) on HUVEC and vSMC to different extents depending on FA type and concentration, cell type and method of analysis. IkappaBalpha phosphorylation in HUVEC and vSMC and transient transfection with NF-kappaB-luciferase reporter plasmid (HUVEC only) indicated differential NF-kappaB involvement during FA modulation (cis-9, trans-11; trans-10, cis-12 and a 50:50 mix of both CLA isomers; eicosapentaenoic acid (EPA); docosahexaenoic acid (DHA)). TNF-alpha-induced ADM expression in both cell types by 2-10-fold. In HUVEC, CLA t10, c12 and CLA mix (50:50 mixture of CLA c9, t11 and t10, c12) and EPA and DHA reduced ICAM-1 expression (15-35%) at 12.5, 25 and/or 50 microM. VCAM-1 expression was reduced by 25 microM t10, c12 isomer and mix; omega-3 PUFA and other concentrations of CLA and TNF-alpha-induced E-selectin expression were unaffected. TNFalpha-induced inhibitor kappa B (IkappaB) phosphorylation was biphasic peaking at 5 min in both cell types and 60 and 120 min in HUVEC and SMC, respectively. IkappaBalpha phosphorylation and NF-kappaB activity was reduced (29% and 30%, respectively) by 25 microM CLA mix. n-3 PUFA did not reduce IkappaBalpha phosphorylation or NF-kappaB activity but reduced ADM expression. We show that n-3 PUFA and CLA reduce expression of ADM on HUVEC and vSMC. This reflected reduced adherence of monocytes to HUVEC previously reported by our group. Reduction of ICAM-1 and VCAM-1 protein expression by n-3 PUFA was less dependent on the NF-kappaB pathway than reduction by CLA which reflected the parallel attenuation of NF-kappaB activity. This indicated involvement of other transcription factors (i.e. AP-1) in the FA regulation of ADM expression and has, to our knowledge, not been previously reported.
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MESH Headings
- Cell Line
- Cells, Cultured
- Endothelial Cells/metabolism
- Endothelium, Vascular/cytology
- Endothelium, Vascular/metabolism
- Fatty Acids, Omega-3/pharmacology
- Humans
- Intercellular Adhesion Molecule-1/metabolism
- Linoleic Acids, Conjugated/pharmacology
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/metabolism
- Myocytes, Smooth Muscle/metabolism
- NF-kappa B/metabolism
- Phosphorylation
- Tumor Necrosis Factor-alpha/metabolism
- Umbilical Veins
- Vascular Cell Adhesion Molecule-1/metabolism
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Affiliation(s)
- M Goua
- School of Life Sciences, Robert Gordon University, St. Andrew Street, Aberdeen, UK
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16
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Downie D, Delday MI, Maltin CA, Sneddon AA. Clenbuterol increases muscle fiber size and GATA-2 protein in rat skeletal muscle in utero. Mol Reprod Dev 2008; 75:785-94. [DOI: 10.1002/mrd.20795] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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17
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Sneddon AA, McLeod E, Wahle KWJ, Arthur JR. Cytokine-induced monocyte adhesion to endothelial cells involves platelet-activating factor: suppression by conjugated linoleic acid. Biochim Biophys Acta Mol Cell Biol Lipids 2006; 1761:793-801. [PMID: 16829183 DOI: 10.1016/j.bbalip.2006.05.014] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2006] [Revised: 04/28/2006] [Accepted: 05/24/2006] [Indexed: 11/30/2022]
Abstract
Monocyte-endothelium interaction is key to many acute and chronic inflammatory diseases. We have investigated the factors regulating monocyte attachment to cytokine-activated human umbilical vein endothelial cells (HUVEC) and the modulatory effect of the polyunsaturated fatty acid (PUFA), conjugated linoleic acid (CLA) in this process. Both TNF-alpha and IL-1beta induced HUVEC platelet-activating factor (PAF) production and PAF was required for subsequent firm THP-1 monocyte adhesion since it was inhibited by both PAF receptor antagonists (BN-52021 or CV-6209) and a PAF synthesis inhibitor (sanguinarine). CLA inhibited the binding of both THP-1 and isolated human peripheral blood monocytes to HUVEC by up to 40% with the CLA t10,c12 isomer suppressing adhesion dose-dependently. Investigation into the mechanism involved demonstrated that with IL-1beta, VCAM-1 and ICAM-1 levels and pro-inflammatory cytokine expression were largely unaffected by CLA. Through the use of PAF receptor antagonists and PAF synthesis inhibitors, CLA was shown to inhibit cytokine-induced binding by suppressing PAF production. Direct assay of PAF levels confirmed this result. We conclude that endothelial-generated PAF plays a central role in cytokine-induced monocyte adherence to endothelium and that the anti-inflammatory action of PUFAs such as CLA in suppressing monocyte-endothelial interaction is mediated through attenuation of pro-inflammatory phospholipids such as PAF.
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Affiliation(s)
- Alan A Sneddon
- Lipid and Redox Regulation Group, Vascular Health Programme, Rowett Research Institute, Bucksburn, Aberdeen AB21 9SB, UK.
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18
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Song HJ, Sneddon AA, Heys SD, Wahle KWJ. Induction of apoptosis and inhibition of NF-kappaB activation in human prostate cancer cells by the cis-9, trans-11 but not the trans-10, cis-12 isomer of conjugated linoleic acid. Prostate 2006; 66:839-46. [PMID: 16491481 DOI: 10.1002/pros.20351] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
BACKGROUND Conjugated linoleic acids (CLAs) have anti-tumorigenic properties in animal models and anti-proliferative effects on cancer cells in vitro. Previous studies have shown that the NF-kappaB pathway is involved regulating anti-apoptotic gene expression. The present study investigated the effects of CLAs (cis-9, trans-11, and trans-10, cis-12 isomers and a 50:50 mixture) on apoptosis and NF-kappaB activation in LNCaP cells. METHODS Apoptosis was assessed by annexin V staining using flow cytometry. TNF-alpha-induced NF-kappaB activity was determined by gel shift and reporter gene assays in addition to monitoring IkappaBalpha phosphorylation. RESULTS Only the CLA cis-9, trans-11 isomer significantly increased TNF-alpha-induced apoptosis (by 59%), which correlated with a reduction in NF-kappaB transcriptional activity (by 35%, P < 0.05), NF-kappaB binding activity (by 15%, P < 0.05), and phosphorylation of IkappaBalpha (by 36%, P < 0.01). CONCLUSIONS Our results may offer a mechanistic explanation for the reported inhibition of prostate tumor growth by CLAs in animal models of disease.
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Affiliation(s)
- Hyun-Ju Song
- The Robert Gordon University, School of Life Sciences, St. Andrews Street, Aberdeen, United Kingdom
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19
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Downie D, Antipatis C, Delday MI, Maltin CA, Sneddon AA. Moderate maternal vitamin A deficiency alters myogenic regulatory protein expression and perinatal organ growth in the rat. Am J Physiol Regul Integr Comp Physiol 2004; 288:R73-9. [PMID: 15458964 DOI: 10.1152/ajpregu.00186.2004] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Vitamin A deficiency is one of the most common dietary deficiencies in the developing world and is a major health concern where it is associated with increased risk of fetal and infant mortality and morbidity. Early studies in the rat demonstrated that, in addition to respiratory problems, neonates showed evidence of mobility problems in response to moderate vitamin A deficiency. This study investigated whether moderate deficiency of this vitamin plays a role in regulating key skeletal muscle regulatory pathways during development. Thirty female rats were fed vitamin A-moderate (VAM) or vitamin A-sufficient diets from weaning and throughout pregnancy. Fetal and neonatal hindlimb and muscle samples were collected on days 13.5, 15.5, 17.5, and 19.5 of pregnancy and 1 day following birth. Mothers fed the VAM diet had reduced retinol concentrations at all time points studied (P < 0.01), and neonates had reduced relative lung weights (P < 0.01). Fetal weight and survival did not differ between groups but neonatal survival was lower in the VAM group where neonates had increased relative heart weights (P < 0.05). Analysis of myogenic regulatory factor expression and calcineurin signaling in fetuses and neonates demonstrated decreased protein levels of myf5 [50% at 17.5 dg (P < 0.05)], myogenin [70% at birth (P < 0.001)], and myosin heavy chain fast [50% at birth (P < 0.05)] in response to moderate vitamin A deficiency. Overall, these changes suggest that vitamin A status during pregnancy may have important implications for fetal muscle development and subsequent muscle function in the offspring.
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Affiliation(s)
- D Downie
- The Rowett Research Institute, Bucksburn, Aberdeen AB21 9SB, Scotland, UK
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20
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Sneddon AA, Wu HC, Farquharson A, Grant I, Arthur JR, Rotondo D, Choe SN, Wahle KWJ. Regulation of selenoprotein GPx4 expression and activity in human endothelial cells by fatty acids, cytokines and antioxidants. Atherosclerosis 2004; 171:57-65. [PMID: 14642406 DOI: 10.1016/j.atherosclerosis.2003.08.008] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Phospholipid hydroperoxide glutathione peroxidase (GPx4) is the only antioxidant enzyme known to directly reduce phospholipid hydroperoxides within membranes and lipoproteins, acting in conjunction with alpha-tocopherol to inhibit lipid peroxidation. Peroxidation of lipids has been implicated in a number of pathophysiological processes, including inflammation and atherogenesis. We investigated the relative positive and negative effects of specific polyunsaturated fatty acids (PUFAs) and inflammatory cytokines on the activity and gene expression of the selenium-dependant redox enzyme GPx4. In human umbilical vein endothelial cells (HUVEC), GPx4 mRNA levels and activity were increased optimally by 114 nM selenium (as sodium selenite). Docosahexaenoic acid (DHA) and conjugated linoleic acid (CLA) further increased mRNA levels whereas arachidonic acid (ARA) had no effect; enzyme activity was decreased by DHA, was unaffected by CLA or was increased by ARA. GPx4 protein levels increased with selenium, ARA and DHA addition but not with CLA. Interleukin-1beta (IL-1beta) increased GPx4 mRNA, protein and activity whereas TNFalpha at 1 ng/ml increased activity while at 3 ng/ml it reduced activity and mRNA. Conversely, alpha-tocopherol reduced mRNA levels without affecting activity. These results indicate that lipids, cytokines and antioxidants modulate GPx4 in a complex manner that in the presence of adequate selenium, may favour protection against potentially proatherogenic processes.
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Affiliation(s)
- Alan A Sneddon
- Lipid and Redox Regulation Group, Rowett Research Institute, Bucksburn, Aberdeen AB21 9SB, UK
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21
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Song HJ, Sneddon AA, Barker PA, Bestwick C, Choe SN, McClinton S, Grant I, Rotondo D, Heys SD, Wahle KWJ. Conjugated Linoleic Acid Inhibits Proliferation and Modulates Protein Kinase C Isoforms in Human Prostate Cancer Cells. Nutr Cancer 2004; 49:100-8. [PMID: 15456642 DOI: 10.1207/s15327914nc4901_14] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Prostate cancer is the second most common cancer in men. The disease etiology is poorly understood, but diet and lifestyle are contributory factors. Conjugated linoleic acids (CLAs), naturally occurring fatty acids in ruminant food products, have antitumor properties in animal models of cancer and antiproliferative effects on cancer cells in vitro. The cellular mechanisms by which CLAs elicit these effects are unclear, particularly for prostate cancer cells. We have previously identified protein kinase C (PKC) isoforms, alpha, delta, iota, mu, and zeta in LNCaP prostate cancer cells. The objective of this study was to determine the effects of CLAs (individual cis-9, trans-11 and trans-10, cis-12 isoforms and a 50:50 mixture) on PKC isoform abundance in LNCaP cells. Confluent cells were treated with 6, 25, and 50 microM CLA for 0.5, 6, and 24 h. Cytosol and membrane protein fractions were assayed for PKC isoforms (mainly alpha and delta but also iota, mu, and zeta) by Western blot analysis using specific antibodies. CLAs clearly modulated the abundance of these PKC isoforms, both positively and negatively, depending on the isoform, concentration of CLAs, and period of treatment. Increased PKC-delta and decreased PKC-iota membrane abundance was consistent with CLAs eliciting increased apoptosis and, in part, with their antitumor effects.
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Affiliation(s)
- Hyun-Ju Song
- The Rowett Research Institute, Bucksburn, Aberdeen, Scotland, UK
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22
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Sneddon AA, Koll M, Wallace MC, Jones J, Miell JP, Garlick PJ, Preedy VR. Acute alcohol administration inhibits the refeeding response after starvation in rat skeletal muscle. Am J Physiol Endocrinol Metab 2003; 284:E874-82. [PMID: 12388171 DOI: 10.1152/ajpendo.00209.2002] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This study determined whether an acute alcohol dose could inhibit the refeeding response in starved muscle. Rats starved for 24 h were pretreated with alcohol or saline before refeeding by intragastric or intravenous infusion of enteral diet (ENT), total parenteral nutrition (TPN), or saline. Refeeding by TPN or ENT stimulated increases in the fractional rate of protein synthesis (k(s)) in skeletal muscle. Alcohol prevented the increase in k(s) when refeeding occurred intragastrically (TPN or ENT) (P < 0.001) but not intravenously (TPN). Upon intragastric refeeding, alcohol inhibited the increase in both eukaryotic initiation factor 4E-binding protein-1 (4E-BP1) and p70 S6 kinase (p70(S6K)) phosphorylation in plantaris but caused only partial inhibition in soleus muscle (ENT only). When rats were refed intravenously, alcohol had no effect on the increased 4E-BP1 or p70(S6K) phosphorylation in either muscle. Plasma insulin levels were augmented by alcohol. Alcohol-related changes in plasma amino acid concentrations were similar irrespective of the route of feeding, whereas IGF-I levels showed differential changes. This is the first study to demonstrate that acute alcohol ingestion impedes the starved-to-fed response in skeletal muscle.
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Affiliation(s)
- A A Sneddon
- Rowett Research Institute, Bucksburn, Aberdeen AB21 9SB, Scotland, UK.
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23
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Sneddon AA, Delday MI, Steven J, Maltin CA. Elevated IGF-II mRNA and phosphorylation of 4E-BP1 and p70(S6k) in muscle showing clenbuterol-induced anabolism. Am J Physiol Endocrinol Metab 2001; 281:E676-82. [PMID: 11551843 DOI: 10.1152/ajpendo.2001.281.4.e676] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Muscle wasting affects large numbers of people, but few therapeutic approaches exist to treat and/or reverse this condition. The beta(2)-adrenoceptor agonist clenbuterol produces a muscle-specific protein anabolism in both normal and catabolic muscle and has been used to limit muscle wasting in humans. Because clenbuterol appears to interact with or mimic innervation, its effect on the expression of the neurotrophic agents insulin-like growth factor (IGF)-II and H19 and their putative pathways was examined in normal rat plantaris muscle. The results showed that the well-documented early effects of clenbuterol on protein metabolism were preceded by elevated levels of IGF-II and H19 transcripts together with increased phosphorylation of eukaryotic initiation factor (eIF)4E binding protein-1 (4E-BP1) and p70(S6k). By 3 days, transcript levels for IGF-II and H19 and 4E-BP1 and p70(S6k) phosphorylation had returned to control values. These novel findings indicate that clenbuterol-induced muscle anabolism is potentially mediated, at least in part, by an IGF-II-induced activation of 4E-BP1 and p70(S6k).
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Affiliation(s)
- A A Sneddon
- The Rowett Research Institute, Bucksburn, Aberdeen AB21 9SB, Scotland, United Kingdom.
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Maltin CA, Delday MI, Sinclair KD, Steven J, Sneddon AA. Impact of manipulations of myogenesis in utero on the performance of adult skeletal muscle. Reproduction 2001; 122:359-74. [PMID: 11597302 DOI: 10.1530/rep.0.1220359] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The possibility that early fetal programming affects health or disease status in adult life has been considered in relation to tissues such as the cardiovascular system but not with respect to skeletal muscle. Since muscle mass and function are important for life, it is pertinent to ask whether events during the development of muscle in utero can affect the performance of the tissue in later life. This review discusses the factors that influence muscle performance, outlines the current understanding of myogenesis and examines how manipulations alter myogenic outcome after birth. The performance of muscle is determined by the number, type and size of the muscle fibres, these in turn being affected by a number of factors, and the evidence indicates that the proportions of types of muscle fibre have a heritable component. The formation of muscle occurs early in embryogenesis and it appears that the major impacts on myogenesis are associated with extremes of treatment or embryo manipulations. The impact of extremes of treatment or embryo manipulations on myogenesis is seen in the secondary fibres whereas primary fibres appear to be insensitive or protected. Overall, the opportunities for manipulation of myogenesis in utero to improve adult performance are limited.
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Affiliation(s)
- C A Maltin
- Rowett Research Institute, Greenburn Road, Bucksburn, Aberdeen, AB21 9SB, UK.
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Pandian SS, Sneddon AA, Bestwick CS, McClinton S, Grant I, Wahle KW, Heys SD. Fatty Acid Regulation of Protein Kinase C Isoforms in Prostate Cancer Cells. Biochem Biophys Res Commun 2001; 283:806-12. [PMID: 11350056 DOI: 10.1006/bbrc.2001.4873] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Polyunsaturated fatty acids influence the aetiology of prostate cancer. Their effects on cellular mechanisms regulating prostate tumorigenesis are unclear. Using prostate cancer cells (LNCaP), we determined effects of n-9-OA, n-6-LA, and n-3-EPA on total PKC and its isoforms in relation to cell proliferation and PSA production. PKC-alpha, delta, gamma, iota, mu, and zeta were present in LNCaP cells; PKC-beta, epsilon, eta, and theta isoforms were not. PKC-alpha was detected only in cytosol; PKC-delta, iota, gamma, and mu were present in cytosol and in membranes. Fatty acids increased cell proliferation, total PKC activity and elicited pro-proliferative effects on specific PKC isoforms (PKC-delta and -iota). EPA and LA increased total PKC activity and reduced membrane-abundance of PKC-delta. OA reduced cytosolic and membrane PKC-delta. Only EPA reduced PKC-gamma membrane abundance. Fatty acids enhanced cytosolic PKC-iota abundance but only EPA and to a lesser extent LA increased its membrane content. Changes in PKC-delta, -iota, and -gamma did not affect PSA production.
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Affiliation(s)
- S S Pandian
- Department of Surgical Oncology, University of Aberdeen, Scotland, AB 25 9ZD, United Kingdom
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Abstract
Rat soleus muscle was denervated for 3 or 7 days, and total membrane protein kinase C (PKC) activity and translocation and immunocytochemical localization of PKC isoforms were examined. Dietary administration of clenbuterol concomitant with denervation ameliorated the atrophic response and was associated with increased membrane PKC activity at both 3 (140%) and 7 (190%) days. Of the five PKC isoforms (alpha, epsilon, theta, zeta, and mu) detected in soleus muscle by Western immunoblotting, clenbuterol treatment affected only the PKC-alpha and PKC-theta forms. PKC-alpha was translocated to the membrane fraction upon denervation, and the presence of clenbuterol increased membrane-bound PKC-alpha and active PKC-alpha as assayed by Ser(657) phosphorylation. PKC-theta protein was downregulated upon denervation, and treatment with clenbuterol further decreased both cytosolic and membrane levels. Immunolocalization of PKC-theta showed differences for regulatory and catalytic domains, with the latter showing fast-fiber type specificity. The results suggest potential roles of PKC-alpha and PKC-theta in the mechanism of action of clenbuterol in alleviating denervation-induced atrophy.
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Affiliation(s)
- A A Sneddon
- The Rowett Research Institute, Bucksburn, Aberdeen, Scotland AB21 9SB.
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Dowd S, Sneddon AA, Keyse SM. Isolation of the human genes encoding the pyst1 and Pyst2 phosphatases: characterisation of Pyst2 as a cytosolic dual-specificity MAP kinase phosphatase and its catalytic activation by both MAP and SAP kinases. J Cell Sci 1998; 111 ( Pt 22):3389-99. [PMID: 9788880 DOI: 10.1242/jcs.111.22.3389] [Citation(s) in RCA: 96] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
We have isolated the human genes encoding the Pyst1 (MKP-3) and Pyst2 (MKP-X) MAP kinase phosphatases. Both genes consist of three exons interrupted by two introns and lack an intron which is conserved in all the other members of this gene family characterised to date. This reinforces the conclusion that Pyst1 and Pyst2 are members of a distinct and structurally homologous subfamily of dual-specificity (Thr/Tyr) MAP kinase phosphatases. We find that Pyst2 mRNA is constitutively expressed in a wide variety of human cell lines including those derived from ovarian, bladder and breast cancers. While there is no evidence for inducible expression of Pyst2 mRNA in human skin fibroblasts in response to cellular stress, Pyst2 mRNA levels are moderately increased in response to serum stimulation. Pyst2 protein is predominantly cytosolic when expressed in COS-1 cells. In common with Pyst1, Pyst2 shows substrate selectivity for the classical p42 (ERK2) isoform of MAP kinase both in vitro and in vivo, displaying much reduced activity towards stress activated MAP kinase isoforms such as JNK-1 and p38/RK. Pyst2 binds p42 MAP kinase in vivo and both MAP kinase binding and substrate selectivity correlate with the ability of different recombinant MAP and SAP kinases to cause catalytic activation of the Pyst2 phosphatase in vitro.
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Affiliation(s)
- S Dowd
- ICRF Molecular Pharmacology Unit, Biomedical Research Centre, Ninewells Hospital, Dundee DD1 9SY, Scotland, UK
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Groom LA, Sneddon AA, Alessi DR, Dowd S, Keyse SM. Differential regulation of the MAP, SAP and RK/p38 kinases by Pyst1, a novel cytosolic dual-specificity phosphatase. EMBO J 1996; 15:3621-32. [PMID: 8670865 PMCID: PMC451978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The Pyst1 and Pyst2 mRNAs encode closely related proteins, which are novel members of a family of dual-specificity MAP kinase phosphatases typified by CL100/MKP-1. Pyst1 is expressed constitutively in human skin fibroblasts and, in contrast to other members of this family of enzymes, its mRNA is not inducible by either stress or mitogens. Furthermore, unlike the nuclear CL100 protein, Pyst1 is localized in the cytoplasm of transfected Cos-1 cells. Like CL100/ MKP-1, Pyst1 dephosphorylates and inactivates MAP kinase in vitro and in vivo. In addition, Pyst1 is able to form a physical complex with endogenous MAP kinase in Cos-1 cells. However, unlike CL100, Pyst1 displays very low activity towards the stress-activated protein kinases (SAPKs) or RK/p38 in vitro, indicating that these kinases are not physiological substrates for Pyst1. This specificity is underlined by the inability of Pyst1 to block either the stress-mediated activation of the JNK-1 SAP kinase or RK/p38 in vivo, or to inhibit nuclear signalling events mediated by the SAP kinases in response to UV radiation. Our results provide the first evidence that the members of the MAP kinase family of enzymes are differentially regulated by dual-specificity phosphatases and also indicate that the MAP kinases may be regulated by different members of this family of enzymes depending on their subcellular location.
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Affiliation(s)
- L A Groom
- ICRF Molecular Pharmacology Unit, Ninewells Hospital, Dundee, UK
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Lewis T, Groom LA, Sneddon AA, Smythe C, Keyse SM. XCL100, an inducible nuclear MAP kinase phosphatase from Xenopus laevis: its role in MAP kinase inactivation in differentiated cells and its expression during early development. J Cell Sci 1995; 108 ( Pt 8):2885-96. [PMID: 7593328 DOI: 10.1242/jcs.108.8.2885] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We have cloned the Xenopus laevis homologue (XCL100) of the human CL100 (Thr/Tyr) MAP kinase phosphatase. Expression of the XCL100 mRNA and protein is inducible by serum stimulation and oxidative/heat stress in a X. laevis kidney cell line. In contrast, XCL100 is constitutively expressed in growing Xenopus oocytes. Recombinant XCL100 protein is able to dephosphorylate both tyrosine and threonine residues of activated p42 MAP kinase in vitro and both the Xenopus and human CL100 proteins were localised predominantly in the nucleus in transfected COS-1 cells. As nuclear translocation of activated MAP kinase is necessary for some of its essential functions in proliferation and cell differentiation our results indicate a role for CL100 in the regulation of these nuclear signalling events. In Xenopus kidney cells both heat shock and serum stimulation lead to transient activation of MAP kinase. However, in contrast to results previously reported from studies on mammalian fibroblasts the inactivation of MAP kinase in these epitheloid cells is rapid and is not dependent on synthesis of new protein. These results indicate that the induction of CL100 (or CL100-like enzymes) may not be required for MAP kinase inactivation in all cell types. Finally, during early embryogenesis, levels of XCL100 mRNA are greatly increased at the mid-blastula transition, suggesting that this enzyme may be involved in the regulation of MAP kinase activity during early development.
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Affiliation(s)
- T Lewis
- ICRF Molecular Pharmacology Unit, Ninewells Hospital, Dundee, Scotland, UK
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Black S, Andrews PD, Sneddon AA, Stark MJ. A regulated MET3-GLC7 gene fusion provides evidence of a mitotic role for Saccharomyces cerevisiae protein phosphatase 1. Yeast 1995; 11:747-59. [PMID: 7668044 DOI: 10.1002/yea.320110806] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Saccharomyces cerevisiae possesses a single essential gene (GLC7) encoding protein phosphatase 1 (PP1). Elevated expression of this gene from the GAL1 promoter is highly detrimental to the cell, causing a growth defect and aberrant bud morphology, which leads to cells exhibiting long, extended buds. By comparison, expression of GLC7 from the weaker MET3 promoter was without significant effect on either growth or morphology. However, repression of GLC7 expression from the MET3 promoter in cells where the MET3-GLC7 fusion was the sole source of PP1 resulted in a mitotic delay. Such cultures showed a massive decrease in the rate of proliferation in conjunction with a significant increase in the proportion of large, budded cells. 4'6-diamidino-2-phenylindole dihydrochloride (DAPI) staining and anti-tubulin immunofluorescence analysis of these cells revealed that many were blocked in mitosis, with a short spindle and DAPI-stained material stretched between the mother and daughter cell within the bud neck. These results support a role for PP1 in the completion of mitosis in S. cerevisiae.
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Affiliation(s)
- S Black
- Department of Biochemistry, The University, Dundee, UK
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Abstract
Protein phosphorylation is an important regulatory phenomenon in yeasts just as in other eukaryotic cells and controls a wide variety of cellular processes. The importance of protein phosphatases as well as protein kinases as key elements in such control is becoming increasingly clear. Over the past four years since the first yeast protein phosphatase gene was isolated, many more such genes have been described and the number of genes encoding protein phosphatase catalytic subunits in Saccharomyces cerevisiae has comfortably entered double figures. Given the genetic approaches available, yeasts offer powerful systems for addressing the cellular roles of these enzymes. This review summarises the results of genetic studies aimed at determining the functions of protein serine/threonine phosphatases in yeast.
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Affiliation(s)
- M J Stark
- Department of Biochemistry, The University, Dundee, UK
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van Zyl W, Huang W, Sneddon AA, Stark M, Camier S, Werner M, Marck C, Sentenac A, Broach JR. Inactivation of the protein phosphatase 2A regulatory subunit A results in morphological and transcriptional defects in Saccharomyces cerevisiae. Mol Cell Biol 1992; 12:4946-59. [PMID: 1328868 PMCID: PMC360427 DOI: 10.1128/mcb.12.11.4946-4959.1992] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
We have determined that TPD3, a gene previously identified in a screen for mutants defective in tRNA biosynthesis, most likely encodes the A regulatory subunit of the major protein phosphatase 2A species in the yeast Saccharomyces cerevisiae. The predicted amino acid sequence of the product of TPD3 is highly homologous to the sequence of the mammalian A subunit of protein phosphatase 2A. In addition, antibodies raised against Tpd3p specifically precipitate a significant fraction of the protein phosphatase 2A activity in the cell, and extracts of tpd3 strains yield a different chromatographic profile of protein phosphatase 2A than do extracts of isogenic TPD3 strains. tpd3 deletion strains generally grow poorly and have at least two distinct phenotypes. At reduced temperatures, tpd3 strains appear to be defective in cytokinesis, since most cells become multibudded and multinucleate following a shift to 13 degrees C. This is similar to the phenotype obtained by overexpression of the protein phosphatase 2A catalytic subunit or by loss of CDC55, a gene that encodes a protein with homology to a second regulatory subunit of protein phosphatase 2A. At elevated temperatures, tpd3 strains are defective in transcription by RNA polymerase III. Consistent with this in vivo phenotype, extracts of tpd3 strains fail to support in vitro transcription of tRNA genes, a defect that can be reversed by addition of either purified RNA polymerase III or TFIIIB. These results reinforce the notion that protein phosphatase 2A affects a variety of biological processes in the cell and provide an initial identification of critical substrates for this phosphatase.
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Affiliation(s)
- W van Zyl
- Department of Molecular Biology, Princeton University, New Jersey 08544
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Abstract
Two genes (PPH21 and PPH22) encoding the yeast homologues of protein serine-threonine phosphatase 2A have been cloned from a Saccharomyces cerevisiae genomic library using a rabbit protein phosphatase 2A cDNA as a hybridization probe. The PPH genes are genetically linked on chromosome IV and are predicted to encode polypeptides each with 74% amino acid sequence identity to rabbit type 2A protein phosphatase, indicating once again the extraordinarily high degree of sequence conservation shown by protein-phosphatases from different species. The two PPH genes show less than 10% amino acid sequence divergence from each other and while disruption of either PPH gene alone is without any major effect, the double disruption is lethal. This indicates that protein phosphatase 2A activity is an essential cellular function in yeast. Measurement of type 2A protein phosphatase activity in yeast strains lacking one or other of the genes indicates that they account for most, if not all, protein phosphatase 2A activity in the cell.
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Affiliation(s)
- A A Sneddon
- Department of Biochemistry, The University, Dundee, UK
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