Low thoracic skeletal muscle index is associated with negative outcomes in 244 patients with respiratory COVID-19.

BACKGROUND: Sarcopenia is associated with negative outcomes in intensive care unit (ICU) patients and during chronic diseases. We aimed to evaluate if low skeletal muscle index (SMI) measured by computed tomography (CT) at the thoracic level is associated with poor outcomes in hospitalized patients with respiratory COVID-19. METHODS: Patients admitted to the hospital between March 1st and June 9, 2020 with a confirmed diagnosis of respiratory COVID-19 in the Emergency Department were included in this retrospective cohort study. SMI was assessed from a transverse CT image at the T12 level. We analysed the association between thoracic SMI and mortality, ICU admissions, infections, length of stay and gravity scores. RESULTS: We included 244 patients, whose median age was 62 (20-95) years, mean body mass index was 28,6 kg/m2, and 34% were obese patients. 102 patients (41,8%) had low thoracic SMI. On multivariable analysis, low thoracic SMI was associated with more infections (OR = 1,88 [1,06-2,98]) and increased length of stay (OR = 1,87 [1,14-3,49]) but not with mortality (OR = 1.37 [0.54-3.52]), whereas it was inversely associated with ICU admission (OR = 5,56 [1,96-16,67]. CONCLUSION: Low SMI measured by CT at the thoracic level T12 is associated with negative outcomes in patients with respiratory COVID-19.

Delayed gastric emptying and altered antrum protein metabolism during activity-based anorexia.

BACKGROUND: Anorexia nervosa, a restrictive eating disorder, is often associated with gastrointestinal disorders, particularly a delayed gastric emptying. However, the mechanisms remained poorly documented. Thus, we aimed to evaluate gastric emptying and antrum protein metabolism in the Activity-Based Anorexia model (ABA). METHODS: Females C57Bl/6 mice were randomized into 3 groups: Control, ABA, and Limited Food Access (LFA). Food access has been progressively limited from 6 h/day at day 6 to 3 h/day at day 9 and until day 17. ABA mice had free access to an activity wheel. Gastric emptying was assessed. On gastric extracts, a proteomic analysis was performed, as well as an evaluation of protein synthesis and protein oxidation. KEY RESULTS: Both LFA and ABA mice exhibited a delayed gastric emptying compared with Controls (P < .05). Proteomic approach revealed 15 proteins that were differentially expressed. Among these proteins, we identified 2 clusters of interest contributing to (i) the organization of muscle fiber with ACTA2, VCL, KRT19, KRT8, and DES proteins and (ii) "heat shock proteins" with STIP1, HSPD1, and HSPA8 proteins. ABA mice specifically exhibited an increased rate of gastric oxidized proteins. CONCLUSIONS AND INFERENCES: Delayed gastric emptying observed in anorectic conditions appears to be secondary to malnutrition. However, an oxidative stress is specifically present in the stomach of ABA mice. Its role remains to be further studied.

Colonic immune cells in irritable bowel syndrome: A systematic review and meta-analysis.

BACKGROUND & AIMS: Increases in mucosal immune cells have frequently been observed in irritable bowel syndrome (IBS) patients. However, this finding is not completely consistent between studies, possibly due to a combination of methodological variability, population differences and small sample sizes. We performed a meta-analysis of case-control studies that compared immune cell counts in colonic biopsies of IBS patients and controls. METHODS: PubMed and Embase were searched in February 2017. Results were pooled using standardized mean difference (SMD) and were considered significant when zero was not within the 95% confidence interval (CI). Heterogeneity was assessed based on I2 statistics where I2  ≤ 50% and I2  > 50% indicated fixed and random effect models, respectively. KEY RESULTS: Twenty-two studies on 706 IBS patients and 401 controls were included. Mast cells were increased in the rectosigmoid (SMD: 0.38 [95% CI: 0.06-0.71]; P = .02) and descending colon (SMD: 1.69 [95% CI: 0.65-2.73]; P = .001) of IBS patients. Increased mast cells were observed in both constipation (IBS-C) and diarrhea predominant IBS (IBS-D). CD3+ T cells were increased in the rectosigmoid (SMD: 0.53 [95% CI: 0.21-0.85]; P = .001) and the descending colon of the IBS patients (SMD: 0.79, 95% CI [0.28-1.30]; P = .002). This was possibly in relation to higher CD4+ T cells in IBS (SMD: 0.33 [95% CI: 0.01-0.65]; P = .04) as there were no differences in CD8+ T cells. CONCLUSIONS & INFERENCES: Mast cells and CD3+ T cells are increased in colonic biopsies of patients with IBS vs non-inflamed controls. These changes are segmental and sometimes IBS-subtype dependent. The diagnostic value of the quantification of colonic mucosal cells in IBS requires further investigation.

Beneficial effects of cathepsin inhibition to prevent chemotherapy-induced intestinal mucositis.

One of the main secondary toxic side effects of anti-mitotic agents used to treat cancer patients is intestinal mucositis. Previous data showed that cathepsin D activity, contributing to the proteolytic lysosomal pathway, is up-regulated during intestinal mucositis in rats. At the same time, cathepsin inhibition limits intestinal damage in animal models of inflammatory bowel diseases. The aim of this study was to evaluate the effects of cathepsin inhibition on methotrexate-induced mucositis in rats. Male Sprague-Dawley rats received saline solution subcutaneously as the control group or 2·5 mg/kg of methotrexate for 3 days (D0-D2). From D0 to D3 methotrexate-treated rats also received intraperitoneal injections of pepstatin A, a specific inhibitor of cathepsin D or E64, an inhibitor of cathepsins B, H and L, or vehicle. Rats were euthanized at D4 and jejunal samples were collected. Body weight and food intake were partially preserved in rats receiving E64 compared with rats receiving vehicle or pepstatin A. Cathepsin D activity, used as a marker of lysosomal pathway, was reduced both in E64 and pepstatin-treated rats. However, villus atrophy and intestinal damage observed in methotrexate-treated rats were restored in rats receiving E64 but not in rats receiving pepstatin A. The intramucosal concentration of proinflammatory cytokines, interleukin-1ß and cytokine-induced neutrophil chemoattractant (CINC)-2, was markedly increased in methotrexate-treated rats receiving vehicle or pepstatin A but not after E64 treatment. In conclusion, a large broad inhibition of cathepsins could represent a new potential target to limit the severity of chemotherapy-induced mucositis as opposed to the inhibition of cathepsin D alone.

Selective expression of histamine receptors H1R, H2R, and H4R, but not H3R, in the human intestinal tract.

BACKGROUND AND AIMS: Histamine is known as a regulator of gastrointestinal functions, such as gastric acid production, intestinal motility, and mucosal ion secretion. Most of this knowledge has been obtained from animal studies. In contrast, in humans, expression and distribution of histamine receptors (HR) within the human gastrointestinal tract are unclear. METHODS: We analysed HR expression in human gastrointestinal tissue specimens by quantitative reverse transcription-polymerase chain reaction and immunostaining. RESULTS: We found that H1R, H2R, and H4R mRNA were expressed throughout the gastrointestinal tract, while H3R mRNA was absent. No significant differences in the distribution of HR were found between different anatomical sites (duodenum, ileum, colon, sigma, and rectum). Immunostaining of neurones and nerve fibres revealed that H3R was absent in the human enteric nervous system; however, H1R and H2R were found on ganglion cells of the myenteric plexus. Epithelial cells also expressed H1R, H2R and, to some extent, H4R. Intestinal fibroblasts exclusively expressed H1R while the muscular layers of human intestine stained positive for both H1R and H2R. Immune cells expressed mRNA and protein for H1R, H2R, and low levels of H4R. Analysis of endoscopic biopsies from patients with food allergy and irritable bowel syndrome revealed significantly elevated H1R and H2R mRNA levels compared with controls. CONCLUSIONS: We have demonstrated that H1R, H2R and, to some extent, H4R, are expressed in the human gastrointestinal tract, while H3R is absent, and we found that HR expression was altered in patients with gastrointestinal diseases.

Epsilon germ-line and IL-4 transcripts are expressed in human intestinal mucosa and enhanced in patients with food allergy.

BACKGROUND: The mechanisms of gastrointestinal (GI) food allergy (FA) are poorly understood. Immunoglobulin E (IgE) is increased in stools from patients with FA, as well as the number of cells carrying IgE in intestinal mucosa, but the origin of IgE production remains unknown. To investigate a local production of IgE in intestine, we analysed the levels of transcripts for epsilon germ-line (epsilonGT), and potential regulators of IgE production, IL-4, IL-13, IFN-gamma, IL-4Ralpha, STAT6 and FcepsilonRIalpha in intestinal mucosa of adult patients with FA. METHODS: Endoscopic biopsies were obtained from the caecum of 25 patients with FA and 14 control patients. The levels of epsilonGT, IL-4, IL-13, IFN-gamma, IL-4Ralpha, STAT6 and FcepsilonRIalpha mRNA were analysed by real-time RT-PCR and compared with unpaired nonparametric Mann-Whitney test. RESULTS: The mean epsilonGT transcript level in caecum was increased in FA patients compared with control patients (P < 0.05). IL-4 mRNA expression was also increased in FA patients (P < 0.05), whereas mRNA expression for IL-13, IFN-gamma, IL-4Ralpha, STAT6 and FcepsilonRIalpha mRNA expression was not altered. However, the ratio of IL-4 mRNA/IFN-gamma mRNA was significantly increased in FA patients (P < 0.05). No correlation was observed between epsilonGT transcripts expression in intestinal mucosa and total IgE levels in serum. CONCLUSIONS: This study shows that (i) epsilonGT transcripts are expressed in human intestinal mucosa; (ii) epsilonGT and IL-4 transcripts are increased in caecal mucosa from patients with FA. These results suggest local production of IgE in intestine that might be of importance for inflammatory reactions in the GI tract.

Glutamine and CXC chemokines IL-8, Mig, IP-10 and I-TAC in human intestinal epithelial cells.

BACKGROUNDS & AIMS: Chemokines are a family of small proteins involved in immune and inflammatory responses. Human intestinal epithelial cells act as a sentinel in the immune response and produce CXC chemokines such as IL-8, Mig, IP-10 and I-TAC. Glutamine has various effects on immuno-inflammatory response in human intestine. METHODS: The present study aimed to determine the effect of glutamine on the IL-8, Mig, IP-10 and I-TAC production by ELISA and their mRNA level by RT-PCR (expressed as % gapdh) in two human intestinal epithelial cell lines Caco-2/TC7 and HCT-8 under basal conditions or during stimulation with combined cytokines. RESULTS: Under basal conditions, studied chemokines were not influenced by glutamine. When intestinal epithelial cells were stimulated with cytokines, increasing concentrations of glutamine from 2 to 10 mM in HCT-8 cells significantly decreased I-TAC and IP-10 mRNA level (respectively 219 to 182%; P < 0.01; 257 to 176%; P < 0.05) and I-TAC and IP-10 production (respectively 21.2 to 13.0; P < 0.05; 696 to 548 ng/prot mg; P < 0.01). Glutamine also reduced IP-10 mRNA level (186 to 135%, P < 0.05) in cytokines-stimulated Caco-2/TC7 cells. CONCLUSIONS: Down-regulation of CXC chemokines by glutamine could contribute to its therapeutic potential in intestinal inflammation and during critical illness.

Cytokine-stimulated nitric oxide production and inducible NO-synthase mRNA level in human intestinal cells: lack of modulation by glutamine.

BACKGROUND & AIMS: Excess NO production has been reported during intestinal inflammation. Modulation of the inflammatory response with nutrients in critically ill patients has gained increasing interest. Glutamine has beneficial effects on gut mucosa but its effects on human intestinal NO production during an inflammatory response are not known. METHODS: Caco-2/TC7 and HCT-8 cells were stimulated with a cytokine mixture (IL-1 beta, TNF alpha, IFN gamma) and duodenal biopsies from human healthy volunteers in organ culture were stimulated with IL-1 beta. All cultures were performed in the presence of 2-10 mmol/l glutamine. NO release in culture supernatant and iNOS mRNA level in cultured cells or biopsies were assessed by nitrate reduction and Griess assay and RT-PCR, respectively. RESULTS: In Caco-2, HCT-8 cells and duodenal biopsies, cytokine stimulation increased iNOS mRNA level 1.2-fold (ns), 3.8-fold (P=0.02), 4.7-fold (P=0.03) and NO production 1.4-fold (ns), 9.1 (P=0.01) and 1.7-fold (P=0.01), respectively. Increasing glutamine concentration had no significant effect on NO production and iNOS mRNA in any type of culture, stimulated or not by cytokines. In various models of human intestinal cells, glutamine does not further increase NO production induced by pro-inflammatory cytokines.

Modulating effect of glutamine on IL-1beta-induced cytokine production by human gut.

BACKGROUND & AIMS: Balance between pro-and anti-inflammatory mediators plays a key role in the pathogenesis and treatment of inflammatory bowel disease. Glutamine can modulate cytokine production by intestinal mucosa in healthy subjects, but studies in inflammatory states are still limited. The aim of this work was to evaluate the effects of glutamine on IL-1beta-induced cytokine production by human gut. METHODS: Duodenal biopsies from healthy volunteers were stimulated in vitro by IL-1beta in the presence of increasing glutamine concentrations. Cytokine production was assessed in culture media by ELISA and cytokine mRNA expression in biopsies by RT-PCR. Results, in pg/mg of tissue, (median [range]), were compared by non-parametric paired tests. RESULTS: IL-1beta stimulation increased IL-6 and IL-8, but did not affect IL-4 and IL-10 production. IL-8 and IL-6 production from stimulated biopsies significantly decreased with increasing glutamine concentration from 0.5 to 10mM, (2543 [828-3634] to 1499 [282-2617] for IL-8, 62 [22-117] to 24 [12-99] for IL-6, both P<0.05), whereas IL-10 production was increased (0.7 [0.2-1.6] to 1.2 [2.6-0.5],P<0.05). Glutamine also increased IL-10 mRNA level in biopsies (P<0.05). IL-4 production was not affected by glutamine. CONCLUSIONS: Glutamine was shown in human intestinal mucosa to reduce the production of the pro-inflammatory cytokines IL-6 and IL-8, and enhance the production of the anti-inflammatory cytokine, IL-10.

Influence of glutamine on cytokine production by human gut in vitro.

BACKGROUND: glutamine modulates cytokine production by immune cells in vitro and protects the gut from experimental enterocolitis, but data on the effect of glutamine on cytokine production in human gut are lacking. AIM: to assess the effect of glutamine pre-treatment in vivo and in vitro on cytokine production by intestinal mucosa. METHODS: nine fasted volunteers received either enteral glutamine or saline over 6 h in a cross-over design. Duodenal biopsies were cultured for 24 h with or without glutamine. Cytokine content of culture media was analysed by ELISA, and the expression of cytokine mRNA in biopsies was assessed by semi-quantitative RT-PCR. RESULTS: glutamine given in vivo and in vitro significantly decreased IL-6 [1.4 (0.8-8.5) vs 8.9 (1.0-43.9)] and IL-8 production [5.8 (0-51.4) vs. 53.0 (2.5-114.6), pg/mg wet tissue], median (range), both P< or =0.01, in comparison to no glutamine experiments. Glutamine did not influence IL-4 production. IL-1beta, IL-10 and TNF-alpha were not detectable in culture media. The expression of any cytokine mRNA was not influenced by glutamine. CONCLUSIONS: glutamine reduces pro-inflammatory cytokine production by human intestinal mucosa, probably by a post-transcriptional pathway. Glutamine could be useful to modulate inflammatory conditions with imbalanced cytokine production.

Changes in growth factor and cytokine mRNA levels after hepatectomy in rat with CCl(4)-induced cirrhosis.

Cirrhotic liver is considered to regenerate less actively than normal liver after hepatic resection. However, the mechanisms responsible for this impaired regeneration and the cross talk of implicated factors still remain unclear. In the present study, mRNA levels for cyclins, growth factors, and cytokines were quantitatively assessed by a RT-PCR method at different times after hepatectomy in order to determine the relationships between these factors and the impaired regenerative process observed in cirrhotic liver. In our model of CCl(4)-induced cirrhosis, mRNA levels for cyclins and thymidine kinase provide evidence for the impaired and delayed hepatic regeneration. Moreover, we observed a significant decrease in interleukin (IL)-6 and tumor necrosis factor-alpha mRNA and a significant increase for IL-1beta mRNA. No significant change of hepatocyte growth factor (HGF) mRNA level was detected, contrasting with the decrease both at mRNA and protein levels in the expression of the c-Met/HGF receptor. Therefore, the impaired regeneration of the cirrhotic liver is associated not only with a lowered level of signals that normally promote liver growth but also with a strong decrease in c-Met receptor despite a normal expression of its specific ligand.