Dietary Advanced Glycation End products interacting with the intestinal epithelium: What do we really know?

Background: Advanced Glycation End products (AGEs) are a heterogeneous group of stable reaction products formed when amino acids, peptides, or proteins are glycated by the non-enzymatic Maillard Reaction. The formation and accumulation of these products in vivo are linked to many inflammation-based pathological outcomes and part of the pathophysiology of non-communicable diseases like eye cataracts and Alzheimer's disease. Since our diet contains high levels of the same compounds, it has been questioned whether their consumption is also detrimental to health. However, this is still under debate. In this context, the intestinal epithelium is an important target tissue since it is chronically exposed to relatively high concentrations of dietary AGEs. Scope of review: This review summarizes the current evidence on the impact of dietary AGEs on the intestinal epithelium and critically reflects on its methodology. Major conclusions: In healthy rodent models, an inflammation-independent impaired intestinal barrier function is claimed; however, dietary AGEs showed anti-inflammatory activity in IBD models. In vitro studies could be a valuable tool to unravel the underlying mechanisms of these effects, however the available studies face some limitations, e.g. lack of the physicochemical characterization of the glycated proteins, the inclusion of the proper controls and the dose-dependency of the effect. In addition, studies using more advanced in vitro models like intestinal organoids and co-cultures with immune cells exposed to gut microbial metabolites derived from the fermentation of AGEs are still needed

The effects of pro-, pre-, and synbiotics on muscle wasting, a systematic review—gut permeability as potential treatment target

Muscle wasting is a frequently observed, inflammation-driven condition in aging and disease, known as sarcopenia and cachexia. Current treatment strategies target the muscle directly and are often not able to reverse the process. Because a reduced gut function is related to systemic inflammation, this might be an indirect target to ameliorate muscle wasting, by administering pro-, pre-, and synbiotics. Therefore, this review aimed to study the potential of pro-, pre-, and synbiotics to treat muscle wasting and to elucidate which metabolites and mechanisms affect the organ crosstalk in cachexia. Overall, the literature shows that Lactobacillus species pluralis (spp.) and possibly other genera, such as Bifidobacterium, can ameliorate muscle wasting in mouse models. The beneficial effects of Lactobacillus spp. supplementation may be attributed to its potential to improve microbiome balance and to its reported capacity to reduce gut permeability. A subsequent literature search revealed that the reduction of a high gut permeability coincided with improved muscle mass or strength, which shows an association between gut permeability and muscle mass. A possible working mechanism is proposed, involving lactate, butyrate, and reduced inflammation in gut–brain–muscle crosstalk. Thus, reducing gut permeability via Lactobacillus spp. supplementation could be a potential treatment strategy for muscle wasting.</p

Lipopolysaccharide‐induced hypothalamic inflammation in cancer cachexia‐anorexia is amplified by tumour‐derived prostaglandin E2

Abstract Background Cachexia‐anorexia syndrome is a complex metabolic condition characterized by skeletal muscle wasting, reduced food intake and prominent involvement of systemic and central inflammation. Here, the gut barrier function was investigated in pancreatic cancer‐induced cachexia mouse models by relating intestinal permeability to the degree of cachexia. We further investigated the involvement of the gut–brain axis and the crosstalk between tumour, gut and hypothalamus in vitro. Methods Two distinct mouse models of pancreatic cancer cachexia (KPC and 4662) were used. Intestinal inflammation and permeability were assessed through fluorescein isothiocyanate dextran (FITC‐dextran) and lipopolysaccharide (LPS), and hypothalamic and systemic inflammation through mRNA expression and plasma cytokines, respectively. To simulate the tumour–gut–brain crosstalk, hypothalamic (HypoE‐N46) cells were incubated with cachexia‐inducing tumour secretomes and LPS. A synthetic mimic of C26 secretome was produced based on its secreted inflammatory mediators. Each component of the mimic was systematically omitted to narrow down the key mediator(s) with an amplifying inflammation. To substantiate its contribution, cyclooxygenase‐2 (COX‐2) inhibitor was used. Results In vivo experiments showed FITC‐dextran was enhanced in the KPC group (362.3 vs. sham 111.4 ng/mL, P < 0.001). LPS was increased to 140.9 ng/mL in the KPC group, compared with sham and 4662 groups (115.8 and 115.8 ng/mL, P < 0.05). Hypothalamic inflammatory gene expression of Ccl2 was up‐regulated in the KPC group (6.3 vs. sham 1, P < 0.0001, 4662 1.3, P < 0.001), which significantly correlated with LPS concentration (r = 0.4948, P = 0.0226). These data suggest that intestinal permeability is positively related to the cachexic degree. Prostaglandin E2 (PGE2) was confirmed to be present in the plasma and PGE2 concentration (log10) in the KPC group was much higher than in 4662 group (1.85 and 0.56 ng/mL, P < 0.001), indicating a role for PGE2 in pancreatic cancer‐induced cachexia. Parallel to in vivo findings, in vitro experiments revealed that the cachexia‐inducing tumour secretomes (C26, LLC, KPC and 4662) amplified LPS‐induced hypothalamic IL‐6 secretion (419%, 321%, 294%, 160%). COX‐2 inhibitor to the tumour cells reduced PGE2 content (from 105 to 102 pg/mL) in the secretomes and eliminated the amplified hypothalamic IL‐6 production. Moreover, results could be reproduced by addition of PGE2 alone, indicating that the increased hypothalamic inflammation is directly related to the PGE2 from tumour. Conclusions PGE2 secreted by the tumour may play a role in amplifying the effects of bacteria‐derived LPS on the inflammatory hypothalamic response. The cachexia‐inducing potential of tumour mice models parallels the loss of intestinal barrier function. Tumour‐derived PGE2 might play a key role in cancer‐related cachexia‐anorexia syndrome via tumour–gut–brain crosstalk

Genome-wide study of DNA methylation shows alterations in metabolic, inflammatory, and cholesterol pathways in ALS

Copyright © 2022 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease with an estimated heritability between 40 and 50%. DNA methylation patterns can serve as proxies of (past) exposures and disease progression, as well as providing a potential mechanism that mediates genetic or environmental risk. Here, we present a blood-based epigenome-wide association study meta-analysis in 9706 samples passing stringent quality control (6763 patients, 2943 controls). We identified a total of 45 differentially methylated positions (DMPs) annotated to 42 genes, which are enriched for pathways and traits related to metabolism, cholesterol biosynthesis, and immunity. We then tested 39 DNA methylation-based proxies of putative ALS risk factors and found that high-density lipoprotein cholesterol, body mass index, white blood cell proportions, and alcohol intake were independently associated with ALS. Integration of these results with our latest genome-wide association study showed that cholesterol biosynthesis was potentially causally related to ALS. Last, DNA methylation at several DMPs and blood cell proportion estimates derived from DNA methylation data were associated with survival rate in patients, suggesting that they might represent indicators of underlying disease processes potentially amenable to therapeutic interventions.The research reported in this publication was supported by grants from The Dutch Research Council (NWO) (VENI scheme grant 09150161810018 to W.v.R.) and Prinses Beatrix Spierfond (neuromuscular fellowship grant W.F19-03 to W.v.R.), The Prinses Beatrix Spierfonds (W.OR20-08 to J.J.F.A.v.V. and J.H.V.), The Canadian Institutes of Health Research (FRN 159279 to J.P.R.), The Dutch Research Council (NWO) (VIDI grant 91719350 to K.P.K.), The European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement no. 772376-EScORIAL to J.H.V.), the Swedish Brain Foundation (grant nos. 2012-0262, 2012-0305, 2013-0279, 2016-0303, 2018-0310, and 2020-0353 to P.M.A.), the Swedish Research Council (grant nos. 2012-3167 and 2017-03100 to P.M.A.), the Knut and Alice Wallenberg Foundation (grant nos. 2012.0091, 2014.0305, and 2020.0232 to P.M.A.), the Ulla-Carin Lindquist Foundation and the Västerbotten County Council (grant no. 56103-7002829 to P.M.A.), and King Gustaf V’s and Queen Victoria’s Freemason’s Foundation. This is an EU Joint Programme–Neurodegenerative Disease Research (JPND) project. The project is supported through the following funding organizations under the aegis of JPND (www.jpnd.eu) [United Kingdom, Medical Research Council (MR/L501529/1; MR/R024804/1) and Economic and Social Research Council (ES/L008238/1)] and through the Motor Neurone Disease Association (MNDA). This study represents independent research part funded by the National Institute for Health Research (NIHR) Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and King’s College London. A.A.-C. is supported by an NIHR Senior Investigator Award. Samples used in this research were entirely/in part obtained from the U.K. National DNA Bank for MND Research, funded by the MND Association and the Wellcome Trust. We would like to thank people with MND and their families for their participation in this project. We acknowledge sample management undertaken by Biobanking Solutions funded by the Medical Research Council at the Centre for Integrated Genomic Medical Research, University of Manchester. R.J.P. is funded through the Gravitation program of the Dutch Ministry of Education, Culture, and Science and the Netherlands Organization for Scientific Research (BRAINSCAPES). G.L.S. was supported by a PhD studentship from the Alzheimer’s Society. S.T.N. acknowledges support through a FightMND Mid-Career Fellowship. V.S. is supported by the Italian Ministry of Health, AriSLA, and E-Rare Joint Transnational Call. A.A.K. is funded by the MNDA and NIHR Maudsley Biomedical Research Centre. D.B., E.T., and H.R. are employees of Biogen. L.H.v.d.B. reports grants from the Netherlands ALS Foundation, grants from The Netherlands Organization for Health Research and Development (Vici scheme), grants from The European Community’s Health Seventh Framework Programme [grant agreement no. 259867 (EuroMOTOR) to L.H.v.d.B.], and grants from The Netherlands Organization for Health Research and Development (the STRENGTH project, funded through the EU Joint Programme–Neurodegenerative Disease Research, JPND), during the conduct of the study. Project MinE Belgium was supported by a grant from IWT (no. 140935), the ALS Liga België, the National Lottery of Belgium, and the KU Leuven Opening the Future Fund. P.V.D. holds a senior clinical investigatorship of FWO-Vlaanderen and is supported by the E. von Behring Chair for Neuromuscular and Neurodegenerative Disorders, the ALS Liga België, and the KU Leuven funds “Een Hart voor ALS”, “Laeversfonds voor ALS Onderzoek”, and the “Valéry Perrier Race against ALS Fund”. This work was supported by the Italian Ministry of Health (Ministero della Salute, Ricerca Sanitaria Finalizzata, grant RF-2016-02362405 to A. Chiò), the Progetti di Rilevante Interesse Nazionale program of the Ministry of Education, University and Research (grant 2017SNW5MB to A. Chiò); the European Commission’s Health Seventh Framework Programme (FP7/2007-2013 under grant agreement 259867 to A. Chiò), and the Joint Programme–Neurodegenerative Disease Research (Strength, ALS-Care and Brain-Mend projects), granted by Italian Ministry of Education, University, and Research. This study was performed under the Department of Excellence grant of the Italian Ministry of Education, University and Research to the “Rita Levi Montalcini” Department of Neuroscience, University of Torino, Italy. We acknowledge funding from the Australian National Health and Medical Research (NHMRC) Council: 1151854, 1083187, 1173790, 1078901, 1113400, 1095215, and 1176913 Enabling Grant #402703 to N.R.W. Additional funding was provided by the Motor Neurone Disease Research Institute of Australia Ice Bucket Challenge grant for the SALSA-SGC consortium. The OATS (used for controls) was facilitated through Twins Research Australia, a national resource in part supported by a Centre for Research Excellence from the Australian NHMRC Council (NHMRC 1079102 to N.R.W.). Funding for this study was awarded by the (NHMRC)/Australian Research Council Strategic Award (grant 401162 to N.R.W.) and NHMRC grants (1405325, 1024224, 1025243, 1045325, 1085606, 568969, and 1093083 to N.R.W.). The collaboration project is cofunded by the PPP Allowance made available by Health~Holland, Top Sector Life Sciences & Health, to stimulate public-private partnerships. This study was supported by the ALS Foundation Netherlands. This work was sponsored by NWO Domain Science for the use of the national computer facilities. A.N.B. is grateful to the Suna and Inan Kirac Foundation and Koc University for the excellent research environment created and for financial support. G.A.R. is supported by the Canadian Institutes of Health. Several authors of this publication are members of the Netherlands Neuromuscular Center (NL-NMD) and the European Reference Network for rare neuromuscular diseases EURO-NMD. French ALS patients of the Pitié-Salpêtrière hospital (Paris) have been collected with ARSla funding support.info:eu-repo/semantics/publishedVersio