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Glutamine (Gln) and arginine (Arg) are conditionally essential amino acids with immunomodulatory properties. The aim of the study was to assess the effects of Gln and Arg alone or in combination on cytokine release by cultured colonic biopsies from patients with active Crohn's disease (CD). Ten consecutive patients [mean (range) age 26 (18-39) y] with active colonic CD (mean CD activity index: 383.7 +/- 129.8) were prospectively included in the study. Eight colonic biopsies were obtained via a colonoscopy and incubated during 18 h with low (physiological) or high (pharmacological) doses of Arg (0.1 or 2 mmol/L designated as Arg(low) or Arg(high), respectively) and Gln (0.6 or 10 mmol/L designated as Gln(low) or Gln(high), respectively). The concentrations of cytokines [interleukin (IL)-4, IL-10, IL-8, IL-6, tumor necrosis factor-alpha (TNFalpha), IL-1beta, interferon-gamma) were assessed by ELISA, and nitric oxide (NO) production was evaluated by Griess assay. Nuclear factor (NF)-kappaB p65 subunit, inhibitor of NFkappaB-alpha, and p38 mitogen-activated protein kinase (MAPK) were assessed by immunoblotting. Arg(high)/Gln(high) decreased the production of TNFalpha, IL-1beta, IL-8, and IL-6 (each P < 0.01). Arg(low)/Gln(high) decreased IL-6 and IL-8 production (both P < 0.01), whereas Arg(high)/Gln(low) did not affect cytokine and NO production. Arg(low)/Gln(high) and Arg(high)/Gln(high) decreased NF-kappaB p65 subunit expression, whereas p38 MAPK was decreased only by Arg(high)/Gln(high). Combined pharmacological doses of Arg and Gln decreased TNFalpha and the main proinflammatory cytokines release in active colonic CD biopsies via NF-kappaB and p38 MAPK pathways. These results could be the basis of prospective studies evaluating the effects of enteral supply of combined Arg and Gln during active CD. [ABSTRACT FROM AUTHOR]

Background: Available data suggest that nutrients can affect intestinal protein metabolism, which contributes to the regulation of gut barrier function.Objective: We aimed to assess whether an oral nutritional supplement (ONS) containing glutamine (as the dipeptide Ala-Gln), carbohydrates, and antioxidants would modulate duodenal protein metabolism in healthy humans.Design: Thirty healthy control subjects were included and, over a period of 5 h, received by nasogastric tube either saline or ONS providing 11.7 kcal/kg as 0.877 g Ala-Gln/kg, 3.9 g carbohydrates/kg, and antioxidants (29.25 mg vitamin C/kg, 9.75 mg vitamin E/kg, 195 microg [beta]-carotene/kg, 5.85 mg Se/kg, and 390 microg Zn/kg) or glutamine (0.585 g/kg, 2.34 kcal/kg). Simultaneously, a continuous intravenous infusion of L-[1-[13]C]-leucine was done until endoscopy. Leucine enrichment was assessed by using gas chromatography-mass spectrometric analysis, and mucosal fractional synthesis rate was calculated by using intracellular amino acid enrichment as precursor. Mucosal proteolytic pathways were also evaluated.Results: ONS infusion resulted in a doubling increase (P < 0.01) of duodenal fractional synthesis rate and a significant (P < 0.05) decrease in cathepsin DDSmediated proteolysis compared with saline, whereas proteasome and Ca[2+]-dependent activities were unaffected. ONS infusion significantly (P < 0.01) decreased duodenal glutathione but not glutathione disulfide concentrations or the ratio of glutathione to glutathione disulfide. Insulinemia increased after ONS infusion, whereas plasma essential amino acids decreased. Infusion of glutamine alone did not reproduce ONS effects.Conclusions: ONS infusion improves duodenal protein balance in healthy humans. Further investigations are needed to study the origin of these effects and to evaluate ONS supply in stressed persons. © American Society for Nutrition [ABSTRACT FROM AUTHOR]

Obesity is often associated with sex-dependent metabolic complications, in which altered intestinal barrier function and gut microbiota contribute. We aimed to characterize in mice the sex-dependent effects of a high fat diet on these parameters. Male and female C57BL/6 mice received a standard (SD) or high fat diet (HFD; 60% kcal from fat) during 14 weeks (W14). Body composition, glucose tolerance, insulin sensitivity, intestinal permeability, colonic expression of 44 genes encoding factors involved in inflammatory response and gut barrier function, cecal microbiota, plasma adipokines and white adipose tissue response have been assessed. Both male and female HFD mice exhibited an increase of body weight and fat mass gain and glucose intolerance compared to SD mice. However, only male HFD mice tended to develop insulin resistance associated to increased Tnfα and Ccl2 mRNA expression in perigonadal adipose tissue. By contrast, only female HFD mice showed significant intestinal hyperpermeability that was associated with more markedly altered colonic inflammatory response. Cecal microbiota richness was markedly reduced in both sexes (Observed species) with sex-dependent modifications at the phyla or family level, e.g. decreased relative abundance of Bacillota and Lachnospiraceae in females, increased of Bacteroidaceae in males. Interestingly, some of these microbiota alterations were correlated with peripheral metabolic and inflammatory markers. In conclusions, male and female mice exhibit different responses to a high fat diet with specific changes of gut microbiota, intestinal barrier function, colonic and white adipose tissue inflammation, metabolic markers and body weight gain. The underlying mechanisms should be deciphered in further investigations., (© 2024. The Author(s).)

Extranodal NK/T-cell lymphoma (ENKTCL) is an Epstein-Barr virus (EBV)-related neoplasm with male dominance and a poor prognosis. A better understanding of the genetic alterations and their functional roles in ENKTCL could help improve patient stratification and treatments. In this study, we performed a comprehensive genetic analysis of 178 ENKTCL cases to delineate the landscape of mutations, copy number alterations (CNA), and structural variations, identifying 34 driver genes including six previously unappreciated ones, namely, HLA-B, HLA-C, ROBO1, CD58, POT1, and MAP2K1. Among them, CD274 (24%) was the most frequently altered, followed by TP53 (20%), CDKN2A (19%), ARID1A (15%), HLA-A (15%), BCOR (14%), and MSN (14%). Chromosome X losses were the most common arm-level CNAs in females (∼40%), and alterations of four X-linked driver genes (MSN, BCOR, DDX3X, and KDM6A) were more frequent in males and females harboring chromosome X losses. Among X-linked drivers, MSN was the most recurrently altered, and its expression was lost in approximately one-third of cases using immunohistochemical analysis. Functional studies of human cell lines showed that MSN disruption promoted cell proliferation and NF-κB activation. Moreover, MSN inactivation increased sensitivity to NF-κB inhibition in vitro and in vivo. In addition, recurrent deletions were observed at the origin of replication in the EBV genome (6%). Finally, by integrating the 34 drivers and 19 significant arm-level CNAs, nonnegative matrix factorization and consensus clustering identified two molecular groups with different genetic features and prognoses irrespective of clinical prognostic factors. Together, these findings could help improve diagnostic and therapeutic strategies in ENKTCL. Significance: Integrative genetic analyses and functional studies in extranodal NK/T-cell lymphoma identify frequent disruptions of X-linked drivers, reveal prognostic molecular subgroups, and uncover recurrent MSN alterations that confer sensitivity to NF-κB inhibition., (©2024 American Association for Cancer Research.)

Proliferative glomerulonephritis is a severe condition that often leads to kidney failure. There is a significant lack of effective treatment for these disorders. Here, following the identification of a somatic PIK3CA gain-of-function mutation in podocytes of a patient, we demonstrate using multiple genetically engineered mouse models, single-cell RNA sequencing, and spatial transcriptomics the crucial role played by this pathway for proliferative glomerulonephritis development by promoting podocyte proliferation, dedifferentiation, and inflammation. Additionally, we show that alpelisib, a PI3Kα inhibitor, improves glomerular lesions and kidney function in different mouse models of proliferative glomerulonephritis and lupus nephritis by targeting podocytes. Surprisingly, we determined that pharmacological inhibition of PI3Kα affects B and T lymphocyte populations in lupus nephritis mouse models, with a decrease in the production of proinflammatory cytokines, autoantibodies, and glomerular complement deposition, which are all characteristic features of PI3Kδ inhibition, the primary PI3K isoform expressed in lymphocytes. Importantly, PI3Kα inhibition does not impact lymphocyte function under normal conditions. These findings were then confirmed in human lymphocytes isolated from patients with active lupus nephritis. In conclusion, we demonstrate the major role played by PI3Kα in proliferative glomerulonephritis and show that in this condition, alpelisib acts on both podocytes and the immune system.

Rationale: Patients with anorexia nervosa (AN) often present sleep disorders and circadian hormonal dysregulation. The role of the microbiota-gut-brain axis in the regulation of feeding behavior has emerged during the last decades but its relationships with the circadian rhythm remains poorly documented. Thus, we aimed to characterize the circadian clock genes expression in peripheral and central tissues in the activity-based anorexia mouse model (ABA), as well as the dynamics of the gut-microbiota composition., Methods: From day 1 to day 17, male and female C57Bl/6 mice were submitted or not to the ABA protocol (ABA and control (CT) groups), which combines a progressive limited access to food and a free access to a running wheel. At day 17, fasted CT and ABA mice were euthanized after either resting (EoR) or activity (EoA) phase (n = 10-12 per group). Circadian clock genes expression was assessed by RT-qPCR on peripheral (liver, colon and ileum) and central (hypothalamic suprachiasmatic nucleus or SCN) tissues. Cecal bacterial taxa abundances were evaluated by qPCR. Data were compared by two-way ANOVA followed by post-tests., Results: ABA mice exhibited a lower food intake, a body weight loss and an increase of diurnal physical activity that differ according with the sex. Interestingly, in the SCN, only ABA female mice exhibited altered circadian clock genes expression (Bmal1, Per1, Per2, Cry1, Cry2). In the intestinal tract, modification of clock genes expression was also more marked in females compared to males. For instance, in the ileum, female mice showed alteration of Bmal1, Clock, Per1, Per2, Cry1, Cry2 and Rev-erbα mRNA levels, while only Per2 and Cry1 mRNAs were affected by ABA model in males. By contrast, in the liver, clock genes expression was more markedly affected in males compared to females in response to ABA. Finally, circadian variations of gut-bacteria abundances were observed in both male and female mice and sex-dependent alteration were observed in response to the ABA model., Conclusions: This study shows that alteration of circadian clock genes expression at both peripheral and central levels occurs in response to the ABA model. In addition, our data underline that circadian variations of the gut-microbiota composition are sex-dependent., (© 2024. The Author(s).)

Background: In patients with obesity and metabolic syndrome (MetS), lifestyle interventions combining diet, in particular, and physical exercise are recommended as the first line treatment. Previous studies have suggested that leucine or arginine supplementation may have beneficial effects on the body composition or insulin sensitivity and endothelial function, respectively. We thus conducted a randomized controlled study to evaluate the effects of a supervised adapted physical activity program associated or not with oral supplementation with leucine and arginine in MetS-complicated patients with obesity. Methods: Seventy-nine patients with obesity and MetS were randomized in four groups: patients receiving arginine and leucine supplementation (ALs group, n = 20), patients on a supervised adapted physical activity program (APA group, n = 20), patients combining ALs and APA (ALs+APA group, n = 20), and a control group (n = 19). After the baseline evaluation (m0), patients received ALs and/or followed the APA program for 6 months (m6). Body composition, MetS parameters, lipid and glucose metabolism markers, inflammatory markers, and a cardiopulmonary exercise test (CPET) were assessed at m0, m6, and after a 3-month wash-out period (m9). Results: After 6 months of intervention, we did not observe variable changes in body weight, body composition, lipid and glucose metabolism markers, inflammatory parameters, or quality of life scores between the four groups. However, during the CPET, the maximal power (Pmax and Ppeak), power, and O2 consumption at the ventilatory threshold (P(VT) and O2(VT)) were improved in the APA and ALs+APA groups (p < 0.05), as well as the forced vital capacity (FVC). Between m6 and m9, a gain in fat mass was only observed in patients in the APA and ALs+APA groups. Conclusion: In our randomized controlled trial, arginine and leucine supplementation failed to improve MetS in patients with obesity, as did the supervised adapted physical activity program and the combination of both. Only the cardiorespiratory parameters were improved by exercise training.

The role of microbiota in eating disorders has recently emerged. Previous data reported that lipopolysaccharides induce anorexia and a decrease of body weight through the activation of toll-like receptor 4 (TLR4). In the activity-based anorexia (ABA) mouse model, an increase of TLR4 expression in intestinal epithelial cells (IEC) has been described. We thus aimed to characterize the role of TLR4 in IEC in the ABA model in male and female mice. For this purpose, Vill-Cre ERT2 -TLR4 LoxP, which are depleted for TLR4 in IEC in response to 4-OH tamoxifen, were submitted (ABA) or not (CT) to the ABA procedure that combined free access to a running wheel and progressive time-limited access to food. We thus compared CT and ABA TLR4 IEC-/- mice to CT and ABA TLR4 IEC+/+ mice. In response to the ABA model, TLR4 IEC+/+ male and female mice exhibited a body weight loss associated to a decrease of lean mass. In TLR4 IEC-/- male mice, body weight loss was delayed and less pronounced compared to TLR4 IEC+/+ male mice. We did not observe a difference of body weight loss in female mice. The body composition remained unchanged between TLR4 IEC-/- and TLR4 IEC+/+ mice in both sexes. In both sexes, ABA TLR4 IEC+/+ mice exhibited an increase of food-anticipatory activity, as well as an increase of immobility time during the open field test. However, female TLR4 IEC-/- mice showed a decrease of the time spent at the centre and an increase of the time spent at the periphery of the open field area, whereas we did not observe differences in the male mice. In conclusion, the invalidation of TLR4 in IEC modified the response to the ABA model in a sex-dependent manner. Further studies should decipher the underlying mechanisms.

Background: Intestinal fibrosis is a common complication in inflammatory bowel disease (IBD) patients without specific treatment. Aryl hydrocarbon receptor (AhR) activation is associated with better outcomes in intestinal inflammation. Development of novel therapies targeting fibrogenic pathways is required and we aimed to screen dietary AhR ligands for their anti-fibrotic properties in TGF-β1-stimulated human colonic fibroblast cells., Methods: The study was conducted using TGF-β1-stimulated CCD-18Co, a human colonic fibroblast cell line in response to increased concentrations of dietary ligands of AhR such as FICZ, ITE, L-kynurenine and curcumin. Fibrosis markers such as α-SMA, COL1A1, COL3A1 and CTGF were assessed. AhR and ANRT RNA were evaluated., Results: TGF-β1 at 10 ng/mL significantly induced mRNA levels for ECM-associated proteins such as CTGF, COL1A1 and COL3A1 in CCD-18Co cells. FICZ from 10 to 1000 nM, L-kynurenine from 0.1 to 10 μM, ITE from 1 to 100 μM or curcumin from 5 to 20 μM had no significant effect on fibrosis markers in TGF-β1-induced CCD-18Co., Conclusions: Our data highlight that none of the tested dietary AhR ligands had an effect on fibrosis markers in TGF-β1-stimulated human colonic fibroblast cells in our experimental conditions. Further studies are now required to identify novel potential targets in intestinal fibrosis.

Background & Aims: In the last decades, the role of microbiota-gut-brain axis has emerged in the regulation of eating behavior and in the pathophysiology of anorexia nervosa (AN) that remains poorly understood. Particularly, a gut-derived dysregulation of immune response has been proposed leading to immunoglobulins directed against appetite-regulating peptides. However, intestinal permeability in patients with anorexia nervosa has been poorly documented., Methods: In the present prospective case-control study, we thus compared intestinal permeability, appetite-regulating peptides and their reactive immunoglobulins measured in severely malnourished women with AN (n = 17; 28 [21-35] y; 14.9 [14.1-15.2] kg/m 2 ) to healthy volunteers (HV, n = 34; 26 [23-35] y; 22.3 [20.6-23.6] kg/m 2 )., Results: Patients with AN exhibited an increased urinary lactulose/mannitol ratio, both in 0-5 h (0.033 [0.013-0.116]) and 5-24 h samples (0.115 [0.029-0.582]), when compared to HV (0.02 [0.008-0.045], p = 0.0074 and 0.083 [0.019-0.290], p = 0.0174, respectively), suggesting an increased intestinal permeability. Urinary excretion of sucralose and plasma zonulin were not different. The levels of plasma total ghrelin and desacyl-ghrelin were increased in patients with AN compared to HV, whereas plasma leptin concentration was decreased. In addition, αMSH remained unchanged compared to HV. Finally, we did not observe any modification of the levels of total or free αMSH, leptin or ghrelin-reactive immunoglobulin G and M, as well as for their affinity properties. Only, a weak decrease of the dissociation constant (kd) for acyl-ghrelin-reactive IgG was observed in patients with AN (p = 0.0411)., Conclusions: In conclusion, severely malnourished patients with AN show a higher intestinal permeability than HV without evidence of an effect on appetite regulating peptides-reactive immunoglobulins., Competing Interests: Conflict of Interest PD is cofounder and shareholder of TargEDys SA company, MC is shareholder of TargEDys SA company. Other authors declared no conflict of interest., (Copyright © 2022 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.)

The gut microbiota produces a wide variety of metabolites, which interact with intestinal cells and contribute to host physiology. The effect of gut commensal bacteria on host protein SUMOylation, an essential ubiquitin-like modification involved in various intestinal functions, remains, however, unknown. Here, we show that short chain fatty acids (SCFAs) and branched chain fatty acids (BCFAs) produced by the gut microbiota increase protein SUMOylation in intestinal cells in a pH-dependent manner. We demonstrate that these metabolites inactivate intestinal deSUMOylases and promote the hyperSUMOylation of nuclear matrix-associated proteins. We further show that BCFAs inhibit the NF-κB pathway, decrease pro-inflammatory cytokine expression, and promote intestinal epithelial integrity. Together, our results reveal that fatty acids produced by gut commensal bacteria regulate intestinal physiology by modulating SUMOylation and illustrate a new mechanism of dampening of host inflammatory responses triggered by the gut microbiota.

Pre-pubertal murine models of acute colitis are lacking. Magnetic resonance colonography (MRC) is a promising minimally invasive tool to assess colitis. We aimed to: 1/ Adapt a model of acute experimental colitis to pre-pubertal rats and determine whether MRC characteristics correlate with histological inflammation. 2/ Test this model by administering a diet supplemented in transforming growth factor β2 to reverse inflammation. Twenty-four rats were randomized at weaning to one of 3 groups: Trinitrobenzene Sulfonic Acid (TNBS) group (n = 8) fed a standard diet, that received an intra-rectal 60 mg/kg dose of TNBS-ethanol; Control group (n = 8) fed standard diet, that received a dose of intra-rectal PBS; TNBS+MODULEN group (n = 8) that received a dose of TNBS and were exclusively fed MODULEN-IBD® after induction of colitis. One week after induction of colitis, rats were assessed by MRC, colon histopathology and inflammation markers (Interleukin 1β, Tumor necrosis factor α, Nitric Oxide Synthase 2 and Cyclooxygenase 2). TNBS induced typical features of acute colitis on histopathology and MRC (increased colon wall thickness, increased colon intensity on T2-weighted images, target sign, ulcers). Treatment with MODULEN-IBD® did not reduce signs of colitis on MRC. Inflammatory marker expression did not differ among study groups., Competing Interests: No authors have competing interests.