The Formation of hybrid complexes between isoenzymes of glyceraldehyde-3-phosphate dehydrogenase regulates its aggregation state, the glycolytic activity and sphingolipid status in Saccharomyces cerevisiae

The glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH) has been traditionally considered a housekeeping protein involved in energy generation. However, evidence indicates that GAPDHs from different origins are tightly regulated and that this regulation may be on the basis of glycolysis-related and glycolysis-unrelated functions. In Saccharomyces cerevisiae, Tdh3 is the main GAPDH, although two other isoenzymes encoded by TDH1 and TDH2 have been identified. Like other GAPDHs, Tdh3 exists predominantly as a tetramer, although dimeric and monomeric forms have also been isolated. Mechanisms of Tdh3 regulation may thus imply changes in its oligomeric state or be based in its ability to interact with Tdh1 and/or Tdh2 to form hybrid complexes. However, no direct evidence of the existence of these interactions has been provided and the exact function of Tdh1,2 is unknown. Here, we show that Tdh1,2 immunopurified with a GFP-tagged version of Tdh3 and that lack of this interaction stimulates the Tdh3's aggregation. Furthermore, we found that the combined knockout of TDH1 and TDH2 promotes the loss of cell's viability and increases the growing rate, glucose consumption and CO2 production, suggesting a higher glycolytic flux in the mutant cells. Consistent with this, the tdh3 strain, which displays impaired in vitro GAPDH activity, exhibited the opposite phenotypes. Quite remarkably, tdh1 tdh2 mutant cells show increased sensitivity to aureobasidin A, an inhibitor of the inositolphosphoryl ceramide synthase, while cells lacking Tdh3 showed improved tolerance. The results are in agreement with a link between glycolysis and sphingolipid (SLs) metabolism. Engineering Tdh activity could be thus exploited to alter the SLs status with consequences in different aspects of yeast biotechnology

Sphingolipids and inositol phosphates regulate the tau protein phosphorylation status in humanized yeast

Hyperphosphorylation of protein tau is a hallmark of Alzheimer's disease (AD). Changes in energy and lipid metabolism have been correlated with the late onset of this neurological disorder. However, it is uncertain if metabolic dysregulation is a consequence of AD or one of the initiating factors of AD pathophysiology. Also, it is unclear whether variations in lipid metabolism regulate the phosphorylation state of tau. Here, we show that in humanized yeast, tau hyperphosphorylation is stimulated by glucose starvation in coincidence with the downregulation of Pho85, the yeast ortholog of CDK5. Changes in inositol phosphate (IP) signaling, which has a central role in energy metabolism, altered tau phosphorylation. Lack of inositol hexakisphosphate kinases Kcs1 and Vip1 (IP6 and IP7 kinases in mammals) increased tau hyperphosphorylation. Similar effects were found by mutation of IPK2 (inositol polyphosphate multikinase), or PLC1, the yeast phospholipase C gene. These effects may be explained by IP-mediated regulation of Pho85. Indeed, this appeared to be the case for plc1, ipk2, and kcs1. However, the effects of Vip1 on tau phosphorylation were independent of the presence of Pho85, suggesting additional mechanisms. Interestingly, kcs1 and vip1 strains, like pho85, displayed dysregulated sphingolipid (SL) metabolism. Moreover, genetic and pharmacological inhibition of SL biosynthesis stimulated the appearance of hyperphosphorylated forms of tau, while increased flux through the pathway reduced its abundance. Finally, we demonstrated that Sit4, the yeast ortholog of human PP2A protein phosphatase, is a downstream effector of SL signaling in mediating the tau phosphorylation state. Altogether, our results add new knowledge on the molecular effectors involved in tauopathies and identify new targets for pharmacological intervention

Myriocin-induced adaptive laboratory evolution of an industrial strain of Saccharomyces cerevisiae reveals its potential to remodel lipid composition and heat tolerance

The modification of lipid composition allows cells to adjust membrane biophysical properties in response to changes in environmental temperature. Here, we use adaptive laboratory evolution (ALE) in the presence of myriocin, a sphingolipid (SLs) biosynthesis inhibitor, to remodel the lipid profile of an industrial yeast strain (LH) of Saccharomyces cerevisiae. The approach enabled to obtain a heterogeneous population (LHev) of myriocin-tolerant evolved clones characterized by its growth capacity at high temperature. Myriocin exposure also caused tolerance to soraphen A, an inhibitor of the acetyl-CoA carboxylase Acc1, the rate-limiting enzyme in fatty acid de novo production, supporting a change in lipid metabolism during ALE. In line with this, characterization of two randomly selected clones, LH03 and LH09, showed the presence of lipids with increased saturation degree and reduced acyl length. In addition, the clone LH03, which displays the greater improvement in fitness at 40°C, exhibited higher SL content as compared with the parental strain. Analysis of the LH03 and LH09 genomes revealed a loss of chromosomes affecting genes that have a role in fatty acid synthesis and elongation. The link between ploidy level and growth at high temperature was further supported by the analysis of a fully isogenic set of yeast strains with ploidy between 1N and 4N which showed that the loss of genome content provides heat tolerance. Consistent with this, a thermotolerant evolved population (LH40°) generated from the parental LH strain by heat-driven ALE exhibited a reduction in the chromosome copy number. Thus, our results identify myriocin-driven evolution as a powerful approach to investigate the mechanisms of acquired thermotolerance and to generate improved strains

One-Year Changes in Urinary Microbial Phenolic Metabolites and the Risk of Type 2 Diabetes—A Case-Control Study

The intake of polyphenols has been associated with a risk reduction of type 2 diabetes. Nevertheless, to the best of our knowledge, the molecules that might be metabolically active after ingestion are only starting to be investigated regarding this metabolic disease. To investigate the association between one-year changes in urinary microbial phenolic metabolites (MPM) and the incidence of type 2 diabetes, we performed a case-control study using data and samples of the PREDIMED trial including 46 incident type 2 diabetes cases of 172 randomly selected participants. Eight urinary MPMs were quantified in urine by liquid chromatography coupled to mass spectrometry and used to assess their associations with type 2 diabetes risk by multivariable logistic regression models. Compared to participants in the lowest tertile of one-year changes in hydroxybenzoic acid glucuronide, those in the highest tertile had a significantly lowered probability of developing type 2 diabetes (OR [95% CI], 0.39 [0.23–0.64]; p < 0.001 for trend). However, when additionally adjusting for fasting plasma glucose, the statistical significance was lost. Changes in the dietary pattern can increase the concentrations of this compound, derived from many (poly)phenol-rich foods, and might be changing the gut microbial population as well, promoting the production of the metabolite.This research was funded by CICYT [AGL2016-75329-R] PID2020-114022RB-I00, CIBEROBN Instituto de Salud Carlos III, ISCIII from the Ministerio de Ciencia, Innovación y Universidades, (AEI/FEDER 10.13039/501100011033, UE), and Generalitat de Catalunya (GC) [2017SGR196]. M.M.-M. is supported by the FPU17/00513 grant. I.D.-L. thanks the Spanish Ministry of Science Innovation and Universities for the Formación de Profesorado Universitario (FPU20/02478) contract. E.P.L.-S. is supported by the FI-SDUR (EM/3345/2020) grant from the Generalitat de Catalunya. I.P.-M. is supported by the FI-SDUR (EMC/2703/2019). Partial funding for open access charge: Universidad de Málaga

Relationship of visceral adipose tissue with surrogate insulin resistance and liver markers in individuals with metabolic syndrome chronic complications

Background: Visceral adipose tissue (VAT) has a hazardous influence on systemic inflammation, insulin resistance and an adverse metabolic profile, which increases the risk of developing non-alcoholic fatty liver disease (NAFLD) and chronic complications of diabetes. In our study we aimed to evaluate the association of VAT and the triglyceride glucose (TyG) as a proxy of insulin resistance surrogated with metabolic and liver risk factors among subjects diagnosed with metabolic syndrome (MetS). Methods: A cross-sectional study was performed including 326 participants with MetS (55-75 years) from the PREDIMED-Plus study. Liver-status markers, VAT and TyG were assessed. Participants were stratified by tertiles according to VAT (n = 254) and TyG (n = 326). A receiver operating characteristic curve was used to analyse the efficiency of TyG for VAT. Results: Subjects with greater visceral fat depots showed worse lipid profile, higher homeostatic model assessment for insulin resistance (HOMA-IR), TyG, alanine transaminase (ALT), fibroblast growth factor-21 (FGF-21), fatty liver index (FLI) and hepatic steatosis index (HSI) compared with participants in the first tertile. The multi-adjusted linear-regression analyses indicated that individuals in the third tertile of TyG (>9.1-10.7) had a positive association with HOMA-IR [beta = 3.07 (95% confidence interval (CI) 2.28-3.86; p trend < 0.001)], ALT [beta = 7.43 (95% CI 2.23-12.63; p trend = 0.005)], gamma glutamyl transferase (GGT) [beta = 14.12 (95% CI 3.64-24.61; p trend = 0.008)], FGF-21 [beta = 190.69 (95% CI 93.13-288.25; p trend < 0.001)], FLI [beta = 18.65 (95% CI 14.97-22.23; p trend < 0.001)] and HSI [beta = 3.46 (95% CI, 2.23-4.68; p trend < 0.001)] versus participants from the first tertile. Interestingly, the TyG showed the largest area under the receiver operating curve (AUC) for women (AUC = 0.713; 95% CI 0.62-0.79) compared with men (AUC = 0.570; 95% CI 0.48-0.66). Conclusions: A disrupted VAT enlargement and impairment of TyG are strongly associated with liver status and cardiometabolic risk factors linked with NAFLD in individuals diagnosed with MetS. Moreover, the TyG could be used as a suitable and reliable marker estimator of VAT

Report of the Scientific Committee of the Spanish Agency for Consumer Affairs, Food Safety and Nutrition (AECOSAN) on a request for initial assessment for marketing of chia ( Salvia hispanica ) seeds in sterilized ready to serve meals based on cereal, pseudocereals and/or pulse grains under Regulation (EC) No 258/97 on novel foods and novel food ingredients

La empresa Herba Ricemills S.L.U. ha solicitado la autorización de la comercialización en la Unión Europea de semillas de chía (Salvia hispanica) como ingrediente de platos preparados esterilizados elaborados a base de granos de cereales, pseudocereales y/o legumbres. Se trataría de una extensión de los usos autorizados para este nuevo alimento en 2009, 2013 y 2015. El Comité Científico considera que de la información aportada no se deduce que el consumo de las semillas de chía (Salvia hispanica) en platos preparados esterilizados basados en granos de cereales, pseudocereales y/o legumbres, en las condiciones propuestas por el solicitante, pueda producir efectos negativos para la salud, concluyendo que el nuevo alimento cumple los criterios de aceptación establecidos por el Reglamento (CE) Nº 258/97 sobre nuevos alimentos y nuevos ingredientes alimentarios (UE, 1997a).The company Herba Ricemills S.L.U. requested authorization to market chia (Salvia hispanica) seeds in sterilized ready to serve meals based on cereal, pseudocereals and/or pulse grains in the European Union. This would be an extension of use of the novel food authorized in 2009, 2013 and 2015. The AECOSAN Scientific Committee takes the view that, according to the information provided, there is no indication that consumption of chia (Salvia hispanica) seeds in ready to serve meals based on cereal, pseudocereals and/or pulse grains, under the conditions proposed by the applicant, can produce adverse effects on health. The Committee concludes that the novel food presented for assessment meets the criteria for acceptance laid down by Regulation (EC) No 258/97 concerning novel foods and novel food ingredients (UE, 1997a)

Report of the Scientific Committee of the Spanish Agency for Consumer Affairs, Food Safety and Nutrition (AECOSAN) on a request for initial assessment for marketing of chia (Salvia hispanica) in chocolate bars under Regulation (EC) No 258/97 on novel foods and novel food ingredients

La empresa Sanchis Mira S.A. ha solicitado la autorización de la comercialización en la Unión Europea de semillas de chía (Salvia hispanica) en chocolate en tabletas. Se trataría de una extensión de los usos autorizados para este nuevo alimento en 2009, 2013 y 2015. El Comité Científico considera que de la información aportada no se deduce que el consumo de las semillas de chía (Salvia hispanica) en chocolate en tabletas, en las condiciones propuestas por el solicitante, pueda producir efectos negativos para la salud, concluyendo que el nuevo alimento cumple los criterios de aceptación establecidos por el Reglamento (CE) Nº 258/97 sobre nuevos alimentos y nuevos ingredientes alimentarios (UE, 1997a).The company Sanchis Mira S.A requested authorization to market chia (Salvia hispanica) seeds in chocolate bars in the European Union. This would be an extension of use of the novel food authorized in 2009, 2013 and 2015. The AECOSAN Scientific Committee takes the view that, according to the information provided, there is no indication that consumption of chia (Salvia hispanica) in chocolate bars, under the conditions proposed by the applicant, can produce adverse effects on health. The Committee concludes that the novel food presented for assessment meets the criteria for acceptance laid down by Regulation (EC) No 258/97 concerning novel foods and novel food ingredients (UE, 1997a)

Report of the Scientific Committee of the Spanish Agency for Consumer Affairs, Food Safety and Nutrition (AECOSAN) on the conditions of use of certain substances to be used in food supplements-4

Los complementos alimenticios son alimentos cuyo fin es complementar la dieta normal y que consisten en fuentes concentradas de nutrientes (vitaminas y minerales) o de otras sustancias que tienen un efecto nutricional o fisiológico, en forma simple o combinada. Los complementos se comercializan en forma dosificada, se entregan al consumidor final únicamente preenvasados. En ningún caso, deben sustituir al uso de medicamentos sin una supervisión médica adecuada. Sólo deben utilizarse para complementar la dieta y, de forma general, su uso no es necesario si se sigue una dieta variada y equilibrada, a la que no pueden reemplazar. En España los complementos alimenticios están regulados por el Real Decreto 1487/2009 que traspuso a la legislación española la Directiva 2002/46/CE relativa a la aproximación de las legislaciones de los estados miembros en materia de complementos alimenticios. Sin embargo, actualmente sólo está regulado el uso de vitaminas y minerales, por lo que se ha solicitado al Comité Científico que realice una valoración de la propuesta de autorización de la utilización de determinadas sustancias distintas de vitaminas y minerales en la fabricación de complementos alimenticios. Las sustancias propuestas por la Agencia Española de Consumo, Seguridad Alimentaria y Nutrición (AECOSAN) son: ácido L-aspártico, L-citrulina, glicina, L-prolina, L-serina, L-arginina-L-aspartato, L-lisina-L-aspartato, L-lisina-L-glutamato, N-acetil-L-cisteína, N-acetil-L-metionina, hidroximetilbu- tirato, ácido lipoico, Monascus purpureus, carbón activo y lactulosa. El Comité Científico ha valorado cada propuesta, analizando las características y fuentes de cada sustancia, así como la nutrición, metabolismo y seguridad y ha concluido, en cada caso, si la presentada por la AECOSAN era aceptable desde el punto de vista de su seguridad en su uso como complemento alimenticio. En ningún caso, la evaluación realizada supone un aval de la eficacia biológica de las sustancias y dosis valoradas. El Comité Científico indica que, en todo caso es necesario que las personas que estén sometidas a tratamientos con medicamentos consulten con su médico la oportunidad o conveniencia de consumir complementos alimenticios dada la posibilidad de que existan interferencias en algunos casos.Food supplements are foods, the purpose of which is to supplement the normal diet and which consist of concentrated nutrient sources (vitamins and minerals) or other substances with a nutritional or physiological effect, alone or in combination. The supplements are marketed in dosage form and are only supplied to the end consumer prepacked. In no event should they replace the use of medicines without suitable medical supervision. They should only be used to supplement the diet and, on the whole, their usage is not required if the individual has a varied and balanced diet, which cannot be replaced. In Spain, food supplements are regulated by Royal Decree 1487/2009, which transposed Directive 2002/46/EC on the approximation of the laws of the Member States relating to food supplements into Spanish law. However, only the use of vitamins and minerals is currently regulated. Therefore the Scientific Committee has been asked to make an assessment of the proposal to authorise certain substances other than vitamins and minerals in the manufacture of food supplements. The substances proposed by the Spanish Agency for Consumer Affairs, Food Safety and Nutrition (AECOSAN) are food supplements, L-aspartic acid, L-citrulline, glycine, L-proline, L-serine, L-arginine-L-aspar- tate, L-lysine L-aspartate, L-lysine-L-glutamate, N-acetyl-L-cysteine, N-acetyl-L-methionine, hidro- xymethylbutyrate, lipoic acid, Monascus purpureus, activated carbon and lactulose. The Scientific Committee has assessed each proposal, analysing the characteristics and sources of each substance, and the nutrition, metabolism and safety and has concluded, in each case, whether that submitted by the AECOSAN is acceptable from a safety viewpoint for use as a food supplement. In no event is the assessment intended as a guarantee of the biological efficiency of the substances and doses assessed. The Scientific Committee states that, in any case individuals undergoing medical treatment must seek medical advice as to the suitability of taking food supplements, given the possibility of interactions in certain cases

Validity of the energy-restricted Mediterranean Diet Adherence Screener

[Background]: Short dietary assessment tools can be useful to estimate food intake and diet quality in large-scale epidemiological studies with time constraints. [Objective]: To determine the concurrent validity of the 17-item energy-restricted Mediterranean Adherence Screener (er-MEDAS) used in the PREDIMED (PREvención con DIeta MEDiterránea)-Plus trial and to analyse its capacity to detect 1-year changes in diet and cardiometabolic risk factors. [Methods]: Validation study nested in the PREDIMED-Plus (n = 6760, 55–75 years). Dietary data were collected by the 17-item er-MEDAS and a 143-item validated semiquantitative food frequency questionnaire (FFQ) at baseline and after 1-year intervention. Cardiometabolic risk markers were measured at both time points. A Mediterranean diet (MedDiet) score was derived from both instruments. Concurrent validity was evaluated by Pearson and intra-class correlation coefficients (ICC) and Bland and Altman limits of agreement. Construct validity was evaluated by assessing 1-year changes in FFQ-reported dietary intake and cardiometabolic profile changes in relation to changes in er-MEDAS. [Results]: A moderate to good correlation between the MedDiet score calculated by both measurement instruments was found: r = 0.61 and ICC = 0.60 (both p < 0.001). Agreement of each of the er-MEDAS items ranged from 55.4% to 85.0% with a moderate mean concordance (kappa = 0.41). Between baseline and 1-year follow-up, energy intake measured by the FFQ decreased by 242 kcal, while Mediterranean food consumption increased in participants with the highest increase in the er-MEDAS MedDiet score. An increase in the er-MEDAS MedDiet score ratings was associated with a decrease in BMI, waist circumference, triglycerides, fasting glucose, diastolic blood pressure, and triglycerides/HDL-cholesterol ratio (p < 0.001 for all), and with an increase in HDL-cholesterol (p = 0.006). [Conclusion]: The er-MEDAS shows a modest to good concurrent validity compared with FFQ data. It shows acceptable construct validity, as a greater er-MEDAS score was associated with more favourable dietary and cardiometabolic profiles over time.The PREDIMED-Plus trial was supported by the official funding agency for biomedical research of the Spanish government, ISCIII through the Fondo de Investigación para la Salud (FIS), which is co-funded by the European Regional Development Fund four coordinated FIS projects led by Jordi Salas-Salvadó and Josep Vidal, including the following projects: PI13/00673, PI13/ 00492, PI13/00272, PI13/01123, PI13/00462, PI13/00233, PI13/02184, PI13/ 00728, PI13/01090, PI13/01056, PI14/01722, PI14/00636, PI14/00618, PI14/ 00696, PI14/01206, PI14/01919, PI14/00853, PI14/01374, PI16/00473, PI16/00662, PI16/01873, PI16/01094, PI16/00501, PI16/00533, PI16/00381, PI16/00366, PI16/01522, PI16/01120, PI17/00764, PI17/01183, PI17/00855, PI17/01347, PI17/00525, PI17/01827, PI17/00532, PI17/00215, PI17/01441, PI17/00508, PI17/01732, PI17/00926; the Special Action Project entitled Implementación y evaluación de una intervención intensiva sobre la actividad física cohorte" PREDIMED-Plus grant to Jordi Salas-Salvadó; the Recercaixa grant to Jordi Salas-Salvadó (2013ACUP00194); the European Research Council Advanced Research Grant 2013–2018 (340918) granted to Miguel Ángel Martínez-Gonzalez, grants from the Consejería de Salud de la Junta de Andalucía (PI0458/2013; PS0358/2016, PI0137/2018), the PROMETEO/2017/017 grant from the Generalitat Valenciana, the SEMERGEN grant and FEDER funds (CB06/03) to Josep A. Tur; the Astra Zeneca Young Investigators Award in Category of Obesity and Diabetes 2017 to Dora Romaguera; the ‘FOLIUM’ programme within the FUTURMed project from the Fundación Instituto de Investigación Sanitaria Illes Balears (financed by 2017annual plan of the sustainable tourism tax and at 50% with charge to the ESF Operational Program 2014–2020 of the Balearic Islands). JR17/00022 contract to Olga Castaner from ISCIII. CIBERobn (Centros de Investigación Biomedica en Red: Obesidad y Nutrición), CIBEResp (Centros de Investigación Biomedica en Red: Epidemiología y Salud Publica) and CIBERdem (Centros de Investigación Biomedica en Red: Diabetes y Enfermedades). J. Salas-Salvadó gratefully acknowledges the financial support provided by the ICREA Academia programme. None of the funding sources took part in the design, collection, analysis, or interpretation of the data; in writing the manuscript; or in the decision to submit the manuscript for publication

Integrative development of a short screening questionnaire of highly processed food consumption (sQ-HPF)

Background: Recent lifestyle changes include increased consumption of highly processed foods (HPF), which has been associated with an increased risk of non-communicable diseases (NCDs). However, nutritional information relies on the estimation of HPF consumption from food-frequency questionnaires (FFQ) that are not explicitly developed for this purpose. We aimed to develop a short screening questionnaire of HPF consumption (sQ-HPF) that integrates criteria from the existing food classification systems. Methods: Data from 4400 participants (48.1% female and 51.9% male, 64.9 +/- 4.9 years) of the Spanish PREDIMED-Plus (PREvention with MEDiterranean DIet) trial were used for this analysis. Items from the FFQ were classified according to four main food processing-based classification systems (NOVA, IARC, IFIC and UNC). Participants were classified into tertiles of HPF consumption according to each system. Using binomial logistic regression, food groups associated with agreement in the highest tertile for at least two classification systems were chosen as items for the questionnaire. ROC analysis was used to determine cut-off points for the frequency of consumption of each item, from which a score was calculated. Internal consistency of the questionnaire was assessed through exploratory factor analysis (EFA) and Cronbach's analysis, and agreement with the four classifications was assessed with weighted kappa coefficients. Results: Regression analysis identified 14 food groups (items) associated with high HPF consumption for at least two classification systems. EFA showed that items were representative contributors of a single underlying factor, the HPF dietary pattern (factor loadings around 0.2). We constructed a questionnaire asking about the frequency of consumption of those items. The threshold frequency of consumption was selected using ROC analysis. Comparison of the four classification systems and the sQ-HPF showed a fair to high agreement. Significant changes in lifestyle characteristics were detected across tertiles of the sQ-HPF score. Longitudinal changes in HPF consumption were also detected by the sQ-HPF, concordantly with existing classification systems. Conclusions: We developed a practical tool to measure HPF consumption, the sQ-HPF. This may be a valuable instrument to study its relationship with NCDs