TY - JOUR A1 - Ruszkiewicz, Joanna A1 - Papatheodorou, Ylea A1 - Jäck, Nathalie A1 - Melzig, Jasmin A1 - Eble, Franziska A1 - Pirker, Annika A1 - Thomann, Marius A1 - Haberer, Andreas A1 - Rothmiller, Simone A1 - Bürkle, Alexander A1 - Mangerich, Aswin T1 - NAD+ Acts as a protective factor in cellular stress response to DNA alkylating agents JF - Cells : open access journal N2 - Sulfur mustard (SM) and its derivatives are potent genotoxic agents, which have been shown to trigger the activation of poly (ADP-ribose) polymerases (PARPs) and the depletion of their substrate, nicotinamide adenine dinucleotide (NAD+). NAD+ is an essential molecule involved in numerous cellular pathways, including genome integrity and DNA repair, and thus, NAD+ supplementation might be beneficial for mitigating mustard-induced (geno)toxicity. In this study, the role of NAD+ depletion and elevation in the genotoxic stress response to SM derivatives, i.e., the monofunctional agent 2-chloroethyl-ethyl sulfide (CEES) and the crosslinking agent mechlorethamine (HN2), was investigated with the use of NAD+ booster nicotinamide riboside (NR) and NAD+ synthesis inhibitor FK866. The effects were analyzed in immortalized human keratinocytes (HaCaT) or monocyte-like cell line THP-1. In HaCaT cells, NR supplementation, increased NAD+ levels, and elevated PAR response, however, did not affect ATP levels or DNA damage repair, nor did it attenuate long- and short-term cytotoxicities. On the other hand, the depletion of cellular NAD+ via FK866 sensitized HaCaT cells to genotoxic stress, particularly CEES exposure, whereas NR supplementation, by increasing cellular NAD+ levels, rescued the sensitizing FK866 effect. Intriguingly, in THP-1 cells, the NR-induced elevation of cellular NAD+ levels did attenuate toxicity of the mustard compounds, especially upon CEES exposure. Together, our results reveal that NAD+ is an important molecule in the pathomechanism of SM derivatives, exhibiting compound-specificity. Moreover, the cell line-dependent protective effects of NR are indicative of system-specificity of the application of this NAD+ booster. KW - nicotinamide adenine dinucleotide KW - NAD booster; KW - mustard agents KW - nicotinamide riboside KW - DNA damage KW - sulfur mustard KW - poly(ADP-ribosylation) KW - PARP Y1 - 2023 U6 - https://doi.org/10.3390/cells12192396 SN - 2073-4409 VL - 12 IS - 19 PB - MDPI CY - Basel ER - TY - JOUR A1 - Sagu Tchewonpi, Sorel A1 - Rawel, Harshadrai M. A1 - Rohn, Sascha T1 - Targeted bottom-up mass spectrometry approach for the relative quantification of post-translational modification of bovine κ-casein during milk fermentation JF - Molecules N2 - kappa-casein (kappa-CN) is one of the key components in bovine milk, playing a unique role in the structuration of casein micelles. It contains in its chemical structure up to sixteen amino acid residues (mainly serine and threonine) susceptible to modifications, including glycosylation and phosphorylation, which may further be formed during milk processing. In this study, changes in post-translational modification (PTM) of kappa-CN during bovine milk fermentation were investigated. One-to-five-day fermented milk samples were produced. A traditional bottom-up proteomics approach was used to establish a multiple-reaction monitoring (MRM) method for relative quantification of kappa-CN PTM. Endoproteinase Glu-C was found to efficiently digest the kappa-CN molecule. The developed LC-MS method was validated by performing assessments of linearity, precision, repeatability, reproducibility, limit of detection (LOD), and limit of quantification (LOQ). Among the yielded peptides, four of them containing serine and threonine residues were identified and the unmodified as well as the modified variants of each of them were relatively quantified. These peptides were (1) IPTINTIASGEPTSTTE ([140, 158]), (2) STVATLE ([162, 168]), (3) DSPE ([169, 172]), and (4) INTVQVTSTAV ([180, 190]). Distribution analysis between unmodified and modified peptides revealed that over 50% of kappa-CN was found in one of its modified forms in milk. The fermentation process further significantly altered the composition between unmodified/modified kappa-CN, with glycoslaytion being predominant compared to phosphorylation (p < 0.01). Further method development towards alpha and beta-CN fractions and their PTM behavior would be an asset to better understand the changes undergone by milk proteins and the micellar structure during fermentation. KW - bovine milk KW - fermentation KW - kappa-casein KW - post-translational modifications KW - glycosylation KW - phosphorylation KW - mass spectrometry Y1 - 2022 U6 - https://doi.org/10.3390/molecules27185834 SN - 1420-3049 VL - 27 IS - 18 PB - MDPI CY - Basel ER - TY - CHAP A1 - Schulze, Kora A1 - Döschner, Larissa A1 - Göger, Lea A1 - Franz, K. A1 - Müller-Werdan, Ursula A1 - Norman, Kristina A1 - Herpich, Catrin T1 - Kurzeitige vegane Intervention senkt Inflammationsmarker BT - Abstracts des Gerontologie und Geriatrie Kongresses 2022 „Altern im Spannungsfeld von Resilienz und Vulnerabilität“ T2 - Zeitschrift für Gerontologie und Geriatrie Y1 - 2022 U6 - https://doi.org/10.1007/s00391-022-02095-7 SN - 0948-6704 SN - 1435-1269 VL - 55 IS - Suppl. 1 SP - S83 EP - S84 PB - Springer Medizin CY - Heidelberg ER - TY - THES A1 - Friese, Sharleen T1 - Trace elements and genomic instability in the murine brain N2 - The trace elements copper, iron, manganese, selenium and zinc are essential micronutrients involved in various cellular processes, all with different responsibilities. Based on that importance, their concentrations are tightly regulated in mammalian organisms. The maintenance of those levels is termed trace element homeostasis and mediated by a combination of processes regulating absorption, cellular and systemic transport mechanisms, storage and effector proteins as well as excretion. Due to their chemical properties, some functions of trace elements overlap, as seen in antioxidative defence, for example, comprising an expansive spectrum of antioxidative proteins and molecules. Simultaneously, the same is true for regulatory mechanisms, causing trace elements to influence each other’s homeostases. To mimic physiological conditions, trace elements should therefore not be evaluated separately but considered in parallel. While many of these homeostatic mechanisms are well-studied, for some elements new pathways are still discovered. Additionally, the connections between dietary trace element intake, trace element status and health are not fully unraveled, yet. With current demographic developments, also the influence of ageing as well as of certain pathological conditions is of increasing interest. Here, the TraceAge research unit was initiated, aiming to elucidate the homeostases of and interactions between essential trace elements in healthy and diseased elderly. While human cohort studies can offer insights into trace element profiles, also in vivo model organisms are used to identify underlying molecular mechanisms. This is achieved by a set of feeding studies including mice of various age groups receiving diets of reduced trace element content. To account for cognitive deterioration observed with ageing, neurodegenerative diseases, as well as genetic mutations triggering imbalances in cerebral trace element concentrations, one TraceAge work package focuses on trace elements in the murine brain, specifically the cerebellum. In that context, concentrations of the five essential trace elements of interest, copper, iron, manganese, selenium and zinc, were quantified via inductively coupled plasma-tandem mass spectrometry, revealing differences in priority of trace element homeostases between brain and liver. Upon moderate reduction of dietary trace element supply, cerebellar concentrations of copper and manganese deviated from those in adequately supplied animals. By further reduction of dietary trace element contents, also concentrations of cerebellar iron and selenium were affected, but not as strong as observed in liver tissue. In contrast, zinc concentrations remained stable. Investigation of aged mice revealed cerebellar accumulation of copper and iron, possibly contributing to oxidative stress on account of their redox properties. Oxidative stress affects a multitude of cellular components and processes, among them, next to proteins and lipids, also the DNA. Direct insults impairing its integrity are of relevance here, but also indirect effects, mediated by the machinery ensuring genomic stability and its functionality. The system includes the DNA damage response, comprising detection of endogenous and exogenous DNA lesions, decision on subsequent cell fate and enabling DNA repair, which presents another pillar of genomic stability maintenance. Also in proteins of this machinery, trace elements act as cofactors, shaping the hypothesis of impaired genomic stability maintenance under conditions of disturbed trace element homeostasis. To investigate this hypothesis, a variety of approaches was used, applying OECD guidelines Organisation for Economic Co-operation and Development, adapting existing protocols for use in cerebellum tissue and establishing new methods. In order to assess the impact of age and dietary trace element depletion on selected endpoints estimating genomic instability, DNA damage and DNA repair were investigated. DNA damage analysis, in particular of DNA strand breaks and oxidatively modified DNA bases, revealed stable physiological levels which were neither affected by age nor trace element supply. To examine whether this is a result of increased repair rates, two steps characteristic for base excision repair, namely DNA incision and ligation activity, were studied. DNA glycosylases and DNA ligases were not reduced in their activity by age or trace element depletion, either. Also on the level of gene expression, major proteins involved in genomic stability maintenance were analysed, mirroring results obtained from protein studies. To conclude, the present work describes homeostatic regulation of trace elements in the brain, which, in absence of genetic mutations, is able to retain physiological levels even under conditions of reduced trace element supply to a certain extent. This is reflected by functionality of genomic stability maintenance mechanisms, illuminating the prioritization of the brain as vital organ. N2 - Als essentielle Mikronährstoffe spielen die Spurenelemente Kupfer, Eisen, Mangan, Selen und Zink eine wichtige Rolle für eine Vielzahl zellulärer Prozesse. Aufgrund dessen unterliegen ihre Konzentrationen in der Peripherie einer strengen Regulation. Die Aufrechterhaltung dieser Konzentrationen wird als Spurenelementhomöostase bezeichnet und beruht auf der Kombination verschiedener Mechanismen hinsichtlich ihrer Absorption, des zellulären und systemischen Transports, der Regulation von Speicher- und Effektorproteinen sowie ihrer jeweiligen Exkretion. Aufgrund ihrer chemischen Eigenschaften überschneiden sich einige Funktionen der Spurenelemente. Beispielsweise ist hier die antioxidative Abwehr zu nennen, an welcher eine Vielzahl verschiedener antioxidativer Moleküle und Proteine beteiligt sind. Gleiches gilt für regulative Mechanismen, wodurch Spurenelemente unter Umständen ihre jeweiligen Homöostasen gegenseitig beeinflussen können. Um physiologische Bedingungen abzubilden, sollten Spurenelemente somit nicht isoliert betrachtet, sondern gemeinsam untersucht werden. Obwohl viele homöostatische Mechanismen bereits gut erforscht sind, werden für einige Elemente immer noch neue Stoffwechselwege identifiziert. Darüber hinaus sind auch die Zusammenhänge zwischen der Spurenelementaufnahme aus der Nahrung sowie dem Spurenelement- und Gesundheitsstatus noch nicht vollständig aufgeklärt. Im Zuge der aktuellen demografischen Entwicklung steigt zudem das Interesse daran, den Einfluss des Alterungsprozesses sowie bestimmter Erkrankungen zu untersuchen. In diesem Kontext wurde die Forschungsgruppe TraceAge gegründet, welche dazu beitragen soll, zum einen die homöostatische Regulation und zum anderen die Interaktionen essentieller Spurenelemente in gesunden und erkrankten älteren Menschen zu untersuchen. Hierbei werden einerseits humane Kohortenstudien beprobt, so dass Spurenelementprofile erstellt werden können. Darüber hinaus werden auch in vivo Modellorganismen verwendet, um zugrundeliegende molekulare Mechanismen zu erfassen. In murinen Fütterungsstudien erhielten Tiere unterschiedlicher Altersgruppen deshalb eine spurenelementreduzierte Diät. Um kognitive Beeinträchtigungen zu beachten, wie sie neben dem Altern auch bei neurodegenerativen Erkrankungen sowie bestimmten genetischen Mutationen, meist im Zusammenhang mit Spurenelementdishomöostasen, auftreten, konzentriert sich ein Projektbereich auf die Wechselwirkung von Spurenelementen im murinen Gehirn, wobei hier der Fokus auf das Cerebellum gelegt wurde. In diesem Zusammenhang wurden die Konzentrationen fünf essentieller Spurenelemente, Kupfer, Eisen, Mangan, Selen und Zink, mittels Massenspektrometrie mit induktiv gekoppeltem Plasma in den Organen der Tiere quantifiziert, wodurch sich Unterschiede in der Priorität der Aufrechterhaltung von Spurenelementhomöostasen zwischen Gehirn und Leber aufzeigten. Eine moderate Verringerung der Spurenelementgehalte in der gefütterten Diät wirkte sich dabei besonders auf die Konzentrationen von cerebellärem Kupfer und Mangan aus. Bei weiterer Spurenelementreduktion sanken auch die Konzentrationen von cerebellärem Eisen und Selen. Im Vergleich zur Leber waren diese Abnahmen jedoch weniger ausgeprägt. Im Gegensatz dazu blieben die Zinkkonzentrationen in Leber und Gehirn unverändert. Untersuchungen in älteren Mäusen zeigten eine Akkumulation von Kupfer und Eisen im Cerebellum. Möglicherweise trägt dies durch deren Redoxeigenschaften zur Entstehung von oxidativem Stress bei. Oxidativer Stress wirkt sich auf eine Vielzahl zellulärer Bestandteile, wie Proteine und Lipide, aber auch auf die DNA, sowie auf den Ablauf von Zellvorgängen aus. Dabei sind einerseits direkte Einflüsse auf die strukturelle Integrität der DNA von Relevanz, andererseits auch indirekte Effekte, welche durch Mechanismen zur Aufrechterhaltung der genomischen Stabilität vermittelt werden. Dieses System beinhaltet die DNA-Schadensantwort, welche die Identifikation von DNA-Schäden und die Entscheidung über das weitere Schicksal der Zelle beinhaltet. Darüber hinaus ist diese für die Initiation der DNA-Reparatur verantwortlich, welche einen weiteren zentralen Mechanismus zur Instandhaltung genomischer Stabilität darstellt. Auch die Proteine der DNA-Reparaturwege nutzen Spurenelemente als Kofaktoren, worin die Hypothese zur Beeinträchtigung der Aufrechterhaltung der genomischen Stabilität unter Bedingungen einer inadäquaten Spurenelementversorgung begründet wird. Um diese Hypothese zu prüfen, wurden in der vorliegenden Arbeit diverse Methoden unter Anwendung von OECD-Richtlinien, der Anpassung existierender Versuchsvorschriften an die spezifischen Anforderungen von Cerebellumgewebe, sowie die Entwicklung neuer Methoden angewandt. Zur Einschätzung des Einflusses von Alter und Spurenelementversorgung aus der Diät auf verschiedene Endpunkte der genomischen Instabilität wurden insbesondere die DNA-Schädigungen und die DNA-Reparatur als molekulare Zielstrukturen analysiert. DNA-Schäden, primär DNA-Strangbrüche und oxidativ modifizierte DNA-Basen, wiesen dabei stabile, physiologische Level auf, die nicht durch Alter oder Spurenelementzufuhr verändert wurden. Um festzustellen, ob dies ein Resultat erhöhter Reparaturvorgänge ist, wurden zwei charakteristische Schritte der Basenexzisionsreparatur, DNA-Inzision und DNA-Ligation, näher untersucht. Es zeigte sich jedoch kein Einfluss auf die DNA-Reparatur einleitenden DNA-Glykosylasen sowie auf die DNA-Reparatur abschließenden DNA-Ligasen. Auch auf Genexpressionsebene wurden wichtige Gene der Proteine der genomischen Stabilität analysiert, welche die Ergebnisse proteinbezogener Studien widerspiegelten. Abschließend lässt sich somit feststellen, dass die Spurenelementhomöostase des Gehirns, selbst unter Bedingungen der defizienten Spurenelementzufuhr, streng reguliert ist. Dadurch können physiologische Spurenelementkonzentrationen bis zu einem gewissen Grad konstant gehalten werden. Dies spiegelt sich auch in der Funktionalität von Mechanismen zur Erhaltung genomischer Stabilität wider, welche die Priorität des Gehirns im Organismus unterstreicht. KW - ageing KW - cerebellum KW - DNA repair KW - genomic instability KW - trace elements KW - Alter KW - Cerebellum KW - DNA-Reparatur KW - genomische Instabilität KW - Spurenelemente Y1 - 2024 ER - TY - JOUR A1 - Schell, Mareike A1 - Kleinridders, André T1 - Intuitives Essen? Zentrale Regulation der Nahrungsaufnahme durch Nährstoffe und Stoffwechselhormone JF - Ernährungsumschau T2 - Intuitive eating? Central regulation of food intake through nutrients and metabolism hormones KW - Adipositas KW - Intuitives Essen KW - Gehirn KW - Stoffwechselhormone KW - Diabetes KW - Nährstoffe KW - Übergewicht Y1 - 2022 SN - 0174-0008 VL - 69 IS - 11 SP - M610 EP - M620 PB - Umschau-Zeitschriftenverlag CY - Frankfurt, M. ER - TY - GEN A1 - Kleinridders, Andre A1 - Maid-Kohnert, Udo T1 - "Intuitives Essen ist für adipöse Patienten nur schwer umzusetzen!" T2 - Ernährungsumschau KW - Insulin KW - Adipositas KW - Intuitives Essen Y1 - 2022 SN - 0174-0008 VL - 69 IS - 11 SP - M622 EP - M625 PB - Umschau-Zeitschriftenverlag CY - Frankfurt am Main ER - TY - JOUR A1 - Puchkov, Dmytro A1 - Müller, Paul Markus A1 - Lehmann, Martin A1 - Matthäus, Claudia T1 - Analyzing the cellular plasma membrane by fast and efficient correlative STED and platinum replica EM JF - Frontiers in cell and developmental biology N2 - The plasma membrane of mammalian cells links transmembrane receptors, various structural components, and membrane-binding proteins to subcellular processes, allowing inter- and intracellular communication. Therefore, membrane-binding proteins, together with structural components such as actin filaments, modulate the cell membrane in their flexibility, stiffness, and curvature. Investigating membrane components and curvature in cells remains challenging due to the diffraction limit in light microscopy. Preparation of 5–15-nm-thin plasma membrane sheets and subsequent inspection by metal replica transmission electron microscopy (TEM) reveal detailed information about the cellular membrane topology, including the structure and curvature. However, electron microscopy cannot identify proteins associated with specific plasma membrane domains. Here, we describe a novel adaptation of correlative super-resolution light microscopy and platinum replica TEM (CLEM-PREM), allowing the analysis of plasma membrane sheets with respect to their structural details, curvature, and associated protein composition. We suggest a number of shortcuts and troubleshooting solutions to contemporary PREM protocols. Thus, implementation of super-resolution stimulated emission depletion (STED) microscopy offers significant reduction in sample preparation time and reduced technical challenges for imaging and analysis. Additionally, highly technical challenges associated with replica preparation and transfer on a TEM grid can be overcome by scanning electron microscopy (SEM) imaging. The combination of STED microscopy and platinum replica SEM or TEM provides the highest spatial resolution of plasma membrane proteins and their underlying membrane and is, therefore, a suitable method to study cellular events like endocytosis, membrane trafficking, or membrane tension adaptations. KW - plasma membrane KW - endocytosis KW - CLEM KW - STED KW - TEM KW - SEM KW - electron microscopy Y1 - 2023 U6 - https://doi.org/10.3389/fcell.2023.1305680 SN - 2296-634X VL - 11 PB - Frontiers Media CY - Lausanne ER - TY - JOUR A1 - Ruszkiewicz, Joanna A1 - Endig, Lisa A1 - Güver, Ebru A1 - Bürkle, Alexander A1 - Mangerich, Aswin T1 - Life-cycle-dependent toxicities of mono- and bifunctional alkylating agents in the 3R-compliant model organism C. elegans JF - Cells : open access journal N2 - Caenorhabditis elegans (C. elegans) is gaining recognition and importance as an organismic model for toxicity testing in line with the 3Rs principle (replace, reduce, refine). In this study, we explored the use of C. elegans to examine the toxicities of alkylating sulphur mustard analogues, specifically the monofunctional agent 2-chloroethyl-ethyl sulphide (CEES) and the bifunctional, crosslinking agent mechlorethamine (HN2). We exposed wild-type worms at different life cycle stages (from larvae L1 to adulthood day 10) to CEES or HN2 and scored their viability 24 h later. The susceptibility of C. elegans to CEES and HN2 paralleled that of human cells, with HN2 exhibiting higher toxicity than CEES, reflected in LC50 values in the high µM to low mM range. Importantly, the effects were dependent on the worms’ developmental stage as well as organismic age: the highest susceptibility was observed in L1, whereas the lowest was observed in L4 worms. In adult worms, susceptibility to alkylating agents increased with advanced age, especially to HN2. To examine reproductive effects, L4 worms were exposed to CEES and HN2, and both the offspring and the percentage of unhatched eggs were assessed. Moreover, germline apoptosis was assessed by using ced-1p::GFP (MD701) worms. In contrast to concentrations that elicited low toxicities to L4 worms, CEES and HN2 were highly toxic to germline cells, manifesting as increased germline apoptosis as well as reduced offspring number and percentage of eggs hatched. Again, HN2 exhibited stronger effects than CEES. Compound specificity was also evident in toxicities to dopaminergic neurons–HN2 exposure affected expression of dopamine transporter DAT-1 (strain BY200) at lower concentrations than CEES, suggesting a higher neurotoxic effect. Mechanistically, nicotinamide adenine dinucleotide (NAD+) has been linked to mustard agent toxicities. Therefore, the NAD+-dependent system was investigated in the response to CEES and HN2 treatment. Overall NAD+ levels in worm extracts were revealed to be largely resistant to mustard exposure except for high concentrations, which lowered the NAD+ levels in L4 worms 24 h post-treatment. Interestingly, however, mutant worms lacking components of NAD+-dependent pathways involved in genome maintenance, namely pme-2, parg-2, and sirt-2.1 showed a higher and compound-specific susceptibility, indicating an active role of NAD+ in genotoxic stress response. In conclusion, the present results demonstrate that C. elegans represents an attractive model to study the toxicology of alkylating agents, which supports its use in mechanistic as well as intervention studies with major strength in the possibility to analyze toxicities at different life cycle stages. KW - C. elegans KW - alkylating agents KW - mustards KW - life cycle toxicities KW - neurotoxicity KW - NAD+ Y1 - 2023 U6 - https://doi.org/10.3390/cells12232728 SN - 2073-4409 VL - 12 IS - 23 PB - MDPI CY - Basel ER - TY - JOUR A1 - Schell, Mareike A1 - Wardelmann, Kristina A1 - Hauffe, Robert A1 - Rath, Michaela A1 - Chopra, Simran A1 - Kleinridders, André T1 - Lactobacillus rhamnosus sex-specifically attenuates depressive-like behavior and mitigates metabolic consequences in obesity JF - Biological psychiatry: global open science N2 - BACKGROUND: Patients with diabetes exhibit an increased prevalence for emotional disorders compared with healthy humans, partially due to a shared pathogenesis including hormone resistance and inflammation, which is also linked to intestinal dysbiosis. The preventive intake of probiotic lactobacilli has been shown to improve dysbiosis along with mood and metabolism. Yet, a potential role of Lactobacillus rhamnosus (Lacticaseibacillus rhamnosus 0030) (LR) in improving emotional behavior in established obesity and the underlying mechanisms are unknown. METHODS: Female and male C57BL/6N mice were fed a low-fat diet (10% kcal from fat) or high-fat diet (HFD) (45% kcal from fat) for 6 weeks, followed by daily oral gavage of vehicle or 1 3 10 8 colony-forming units of LR, and assessment of anxiety- and depressive-like behavior. Cecal microbiota composition was analyzed using 16S ribosomal RNA sequencing, plasma and cerebrospinal fluid were collected for metabolomic analysis, and gene expression of different brain areas was assessed using reverse transcriptase quantitative polymerase chain reaction. RESULTS: We observed that 12 weeks of HFD feeding induced hyperinsulinemia, which was attenuated by LR application only in female mice. On the contrary, HFD-fed male mice exhibited increased anxiety- and depressive-like behavior, where the latter was specifically attenuated by LR application, which was independent of metabolic changes. Furthermore, LR application restored the HFD-induced decrease of tyrosine hydroxylase, along with normalizing cholecystokinin gene expression in dopaminergic brain regions; both tyrosine hydroxylase and cholecystokinin are involved in signaling pathways impacting emotional disorders. CONCLUSIONS: Our data show that LR attenuates depressive-like behavior after established obesity, with changes in the dopaminergic system in male mice, and mitigates hyperinsulinemia in obese female mice. Y1 - 2023 U6 - https://doi.org/10.1016/j.bpsgos.2023.02.011 SN - 2667-1743 VL - 3 IS - 4 SP - 651 EP - 662 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Kroke, Anja A1 - Schmidt, Annemarie A1 - Amini, Anna M. A1 - Kalotai, Nicole A1 - Lehmann, Andreas A1 - Haardt, Julia A1 - Bauer, Jürgen M. A1 - Bischoff-Ferrari, Heike A. A1 - Boeing, Heiner A1 - Egert, Sarah A1 - Ellinger, Sabine A1 - Kühn, Tilman A1 - Louis, Sandrine A1 - Lorkowski, Stefan A1 - Nimptsch, Katharina A1 - Remer, Thomas A1 - Schulze, Matthias B. A1 - Siener, Roswitha A1 - Stangl, Gabriele A1 - Volkert, Dorothee A1 - Zittermann, Armin A1 - Buyken, Anette E. A1 - Watzl, Bernhard A1 - Schwingshackl, Lukas T1 - Dietary protein intake and health-related outcomes: a methodological protocol for the evidence evaluation and the outline of an evidence to decision framework underlying the evidence-based guideline of the German Nutrition Society JF - European journal of nutrition N2 - Purpose: The present work aimed to delineate (i) a revised protocol according to recent methodological developments in evidence generation, to (ii) describe its interpretation, the assessment of the overall certainty of evidence and to (iii) outline an Evidence to Decision framework for deriving an evidence-based guideline on quantitative and qualitative aspects of dietary protein intake. Methods A methodological protocol to systematically investigate the association between dietary protein intake and several health outcomes and for deriving dietary protein intake recommendations for the primary prevention of various non-communicable diseases in the general adult population was developed. Results The developed methodological protocol relies on umbrella reviews including systematic reviews with or without meta-analyses. Systematic literature searches in three databases will be performed for each health-related outcome. The methodological quality of all selected systematic reviews will be evaluated using a modified version of AMSTAR 2, and the outcome-specific certainty of evidence for systematic reviews with or without meta-analysis will be assessed with NutriGrade. The general outline of the Evidence to Decision framework foresees that recommendations in the derived guideline will be given based on the overall certainty of evidence as well as on additional criteria such as sustainability. Conclusion The methodological protocol permits a systematic evaluation of published systematic reviews on dietary protein intake and its association with selected health-related outcomes. An Evidence to Decision framework will be the basis for the overall conclusions and the resulting recommendations for dietary protein intake. KW - Evidence-based guideline KW - Protein intake KW - Method KW - Prevention KW - Nutrition-related diseases Y1 - 2022 U6 - https://doi.org/10.1007/s00394-021-02789-5 SN - 1436-6207 SN - 1436-6215 VL - 61 IS - 4 SP - 2091 EP - 2101 PB - Springer Nature CY - Heidelberg ER -