A high-fat diet has been associated with an increased risk of ulcerative colitis (UC). We studied the effects of a low-fat, high-fiber diet (LFD) vs an improved standard American diet (iSAD, included ...higher quantities of fruits, vegetables, and fiber than a typical SAD). We collected data on quality of life, markers of inflammation, and fecal markers of intestinal dysbiosis in patients with UC.
We analyzed data from a parallel-group, cross-over study of 17 patients with UC in remission or with mild disease (with a flare within the past 18 mo), from February 25, 2015, through September 11, 2018. Participants were assigned randomly to 2 groups and received a LFD (10% of calories from fat) or an iSAD (35%–40% of calories from fat) for the first 4-week period, followed by a 2-week washout period, and then switched to the other diet for 4 weeks. All diets were catered and delivered to patients’ homes, and each participant served as her or his own control. Serum and stool samples were collected at baseline and week 4 of each diet and analyzed for markers of inflammation. We performed 16s ribosomal RNA sequencing and untargeted and targeted metabolomic analyses on stool samples. The primary outcome was quality of life, which was measured by the short inflammatory bowel disease (IBD) questionnaire at baseline and week 4 of the diets. Secondary outcomes included changes in the Short-Form 36 health survey, partial Mayo score, markers of inflammation, microbiome and metabolome analysis, and adherence to the diet.
Participants’ baseline diets were unhealthier than either study diet. All patients remained in remission throughout the study period. Compared with baseline, the iSAD and LFD each increased quality of life, based on the short IBD questionnaire and Short-Form 36 health survey scores (baseline short IBD questionnaire score, 4.98; iSAD, 5.55; LFD, 5.77; baseline vs iSAD, P = .02; baseline vs LFD, P = .001). Serum amyloid A decreased significantly from 7.99 mg/L at baseline to 4.50 mg/L after LFD (P = .02), but did not decrease significantly compared with iSAD (7.20 mg/L; iSAD vs LFD, P = .07). The serum level of C-reactive protein decreased numerically from 3.23 mg/L at baseline to 2.51 mg/L after LFD (P = .07). The relative abundance of Actinobacteria in fecal samples decreased from 13.69% at baseline to 7.82% after LFD (P = .017), whereas the relative abundance of Bacteroidetes increased from 14.6% at baseline to 24.02% on LFD (P = .015). The relative abundance of Faecalibacterium prausnitzii was higher after 4 weeks on the LFD (7.20%) compared with iSAD (5.37%; P = .04). Fecal levels of acetate (an anti-inflammatory metabolite) increased from a relative abundance of 40.37 at baseline to 42.52 on the iSAD and 53.98 on the LFD (baseline vs LFD, P = .05; iSAD vs LFD, P = .09). The fecal level of tryptophan decreased from a relative abundance of 1.33 at baseline to 1.08 on the iSAD (P = .43), but increased to a relative abundance of 2.27 on the LFD (baseline vs LFD, P = .04; iSAD vs LFD, P = .08); fecal levels of lauric acid decreased after LFD (baseline, 203.4; iSAD, 381.4; LFD, 29.91; baseline vs LFD, P = .04; iSAD vs LFD, P = .02).
In a cross-over study of patients with UC in remission, we found that a catered LFD or iSAD were each well tolerated and increased quality of life. However, the LFD decreased markers of inflammation and reduced intestinal dysbiosis in fecal samples. Dietary interventions therefore might benefit patients with UC in remission. ClinicalTrials.gov no: NCT04147598.
Chronic colonic inflammation leads to dysplasia and cancer in patients with inflammatory bowel disease. We have described the critical role of innate immune signaling via Toll-like receptor 4 (TLR4) ...in the pathogenesis of dysplasia and cancer. In the current study, we interrogate the intersection of TLR4 signaling, epithelial redox activity, and the microbiota in colitis-associated neoplasia.
Inflammatory bowel disease and colorectal cancer data sets were analyzed for expression of TLR4, dual oxidase 2 (DUOX2), and NADPH oxidase 1 (NOX1). Epithelial production of hydrogen peroxide (H2O2) was analyzed in murine colonic epithelial cells and colonoid cultures. Colorectal cancer models were carried out in villin-TLR4 mice, carrying a constitutively active form of TLR4, their littermates, and villin-TLR4 mice backcrossed to DUOXA-knockout mice. The role of the TLR4-shaped microbiota in tumor development was tested in wild-type germ-free mice.
Activation of epithelial TLR4 was associated with up-regulation of DUOX2 and NOX1 in inflammatory bowel disease and colorectal cancer. DUOX2 was exquisitely dependent on TLR4 signaling and mediated the production of epithelial H2O2. Epithelial H2O2 was significantly increased in villin-TLR4 mice; TLR4-dependent tumorigenesis required the presence of DUOX2 and a microbiota. Mucosa-associated microbiota transferred from villin-TLR4 mice to wild-type germ-free mice caused increased H2O2 production and tumorigenesis.
Increased TLR4 signaling in colitis drives expression of DUOX2 and epithelial production of H2O2. The local milieu imprints the mucosal microbiota and imbues it with pathogenic properties demonstrated by enhanced epithelial reactive oxygen species and increased development of colitis-associated tumors. The inter-relationship between epithelial reactive oxygen species and tumor-promoting microbiota requires a 2-pronged strategy to reduce the risk of dysplasia in colitis patients.
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The dextran sulfate sodium (DSS) model of colitis is a common animal model of inflammatory bowel disease that causes pain and distress. In this study, we aimed to determine whether fluid ...supplementation can be used as a welfare-based intervention to minimize animal suffering. C57Bl/6 females undergoing acute colitis by administration of 3% DSS in drinking water were supplemented with 1 mL intraperitoneal injections of NaCl and compared to non-supplemented control mice. Mouse behavior and locomotive activity were assessed on days 5-6 after DSS initiation by means of tail suspension, novel object recognition and open field activity tests. Mice were euthanized after either the acute (day 7) or the recovery phase (day 12) of colitis and inflammation, epithelial proliferation, and differentiation were assessed by means of histology, immunohistochemistry, quantitative PCR, and western blot. We found that fluid-supplemented mice had reduced signs of colitis with no alterations in behavior or locomotive activity. Furthermore, we observed an accelerated epithelial repair response after fluid hydration during the acute phase of colitis, characterized by increased crypt proliferation, activation of ERK1/2, and modulation of TGF-β1 expression. Consistent with these findings, fluid-supplemented mice had increased numbers of goblet cells, upregulated expression of differentiation markers for absorptive enterocytes, and reduced inflammation during the recovery phase. Our results show that fluid hydration does not reduce stress in DSS-treated mice but alters colitis evolution by reducing clinical signs and accelerating epithelial repair. These results argue against the routine use of fluid supplementation in DSS-treated mice.
Los padres de niños pequeños deben ser interactivos, responsables y estar disponibles para cuidarlos (Lamb, Pleck, y Levine 1985). Esta investigación pretende arrojar luz sobre hasta qué punto los ...horarios de trabajo en España permiten a los padres estar disponibles para sus hijos cuando estos salen del colegio o la guardería. Usando datos de uso del tiempo, se pretende contribuir a la literatura ofreciendo un análisis detallado de cuánto y cuándo se trabaja a lo largo del día, así como su relación con el estatus ocupacional y parental, el género y la incidencia de la crisis. Se analiza el “tiempo disponible” para la familia, entendido como el tiempo en que no se está en el trabajo, excluyendo las horas estándar “de oficina” (de 8 a 17). Los resultados muestran que ser madre aún tiene una relación directa con el tiempo disponible, no así la paternidad. Además, el tiempo disponible presenta una relación compleja con la estructura de clase, que la crisis no ha alterado. Por último, se comprueba una tendencia convergente entre hombres y mujeres, debido a la reducción del tiempo disponible de estas últimas.
El teletrabajo está en auge desde el estallido de la pandemia. Se trata de una forma de organizar el trabajo que presenta ventajas, pero también algunos riesgos, como la difuminación de las fronteras ...entre la vida personal y la profesional, que puede ser fuente de conflictos. Este estudio analiza el conflicto entre la vida familiar y el trabajo (en ambas direcciones) para una muestra de personas teletrabajadoras extraída de un estudio del CIS realizado en octubre de 2020. Se analizan tres fenómenos principales: las características de las personas que experimentan el conflicto con mayor frecuencia, la influencia del conflicto en la preferencia por el teletrabajo y la relación del teletrabajo con el conflicto intrapareja. Se confirma que el conflicto trabajo-familia, en todas sus formas, es un fenómeno altamente feminizado.
Treatment with combined immune checkpoint blockade (CICB) targeting CTLA-4 and PD-1 is associated with clinical benefit across tumor types, but also a high rate of immune-related adverse events. ...Insights into biomarkers and mechanisms of response and toxicity to CICB are needed. To address this, we profiled the blood, tumor and gut microbiome of 77 patients with advanced melanoma treated with CICB, with a high rate of any ≥grade 3 immune-related adverse events (49%) with parallel studies in pre-clinical models. Tumor-associated immune and genomic biomarkers of response to CICB were similar to those identified for ICB monotherapy, and toxicity from CICB was associated with a more diverse peripheral T-cell repertoire. Profiling of gut microbiota demonstrated a significantly higher abundance of Bacteroides intestinalis in patients with toxicity, with upregulation of mucosal IL-1β in patient samples of colitis and in pre-clinical models. Together, these data offer potential new therapeutic angles for targeting toxicity to CICB.
A subset of regulatory B cells (Bregs) in mice negatively regulate T-cell immune responses through the secretion of regulatory cytokines such as IL-10 and direct cell-cell contact and have been ...linked to experimental models of autoimmunity, inflammation, and cancer. However, the regulatory function of Bregs in human disease is much less clear. Here we demonstrate that B cells with immunoregulatory properties are enriched within both the CD19+IgM+CD27+ memory and CD19+CD24hiCD38hi transitional B-cell subsets in healthy human donors. Both subsets suppressed the proliferation and interferon-γ production of CD3/CD28-stimulated autologous CD4+ T cells in a dose-dependent manner, and both relied on IL-10 secretion as well as cell-cell contact, likely mediated through CD80 and CD86, to support their full suppressive function. Moreover, after allogeneic stem cell transplantation, Bregs from patients with chronic graft-versus-host disease (cGVHD) were less frequent and less likely to produce IL-10 than were Bregs from healthy donors and patients without cGVHD. These findings suggest that Bregs may be involved in the pathogenesis of cGVHD and support future investigation of regulatory B cell–based therapy in the treatment of this disease.
•Human IgM memory B cells possess immunoregulatory properties analogous to transitional B cells.•IL-10–producing B cells are deficient in cGVHD.
Immune checkpoint therapy with anti-CTLA-4 and anti-PD-1/PD-L1 has revolutionized the treatment of many solid tumors. However, the clinical efficacy of immune checkpoint therapy is limited to a ...subset of patients with specific tumor types
. Multiple clinical trials with combinatorial immune checkpoint strategies are ongoing; however, the mechanistic rationale for tumor-specific targeting of immune checkpoints is elusive. To garner an insight into tumor-specific immunomodulatory targets, we analyzed 94 patients representing five different cancer types, including those that respond relatively well to immune checkpoint therapy and those that do not, such as glioblastoma multiforme, prostate cancer and colorectal cancer. Through mass cytometry and single-cell RNA sequencing, we identified a unique population of CD73
macrophages in glioblastoma multiforme that persists after anti-PD-1 treatment. To test if targeting CD73 would be important for a successful combination strategy in glioblastoma multiforme, we performed reverse translational studies using CD73
mice. We found that the absence of CD73 improved survival in a murine model of glioblastoma multiforme treated with anti-CTLA-4 and anti-PD-1. Our data identified CD73 as a specific immunotherapeutic target to improve antitumor immune responses to immune checkpoint therapy in glioblastoma multiforme and demonstrate that comprehensive human and reverse translational studies can be used for rational design of combinatorial immune checkpoint strategies.
The microbes in the gastrointestinal tract are separated from the host by a single layer of intestinal epithelial cells (IECs) that plays pivotal roles in maintaining homeostasis by absorbing ...nutrients and providing a physical and immunological barrier to potential pathogens. Preservation of homeostasis requires the crosstalk between the epithelium and the microbial environment. One epithelial-driven innate immune mechanism that participates in host-microbe communication involves the release of reactive oxygen species (ROS), such as hydrogen peroxide (H
2
O
2
), toward the lumen. Phagocytes produce high amounts of ROS which is critical for microbicidal functions; the functional contribution of epithelial ROS, however, has been hindered by the lack of methodologies to reliably quantify extracellular release of ROS. Here, we used a modified Amplex Red assay to investigate the inflammatory and microbial regulation of IEC-generated H
2
O
2
and the potential role of Duox2, a NADPH oxidase that is an important source of H
2
O
2
. We found that colonoids respond to interferon-γ and flagellin by enhancing production of H
2
O
2
in a Duox2-mediated fashion. To extend these findings, we analyzed
ex vivo
production of H
2
O
2
by IECs after acute and chronic inflammation, as well as after exposure to dysbiotic microbiota. While acute inflammation did not induce a significant increase in epithelial-driven H
2
O
2
, chronic inflammation caused IECs to release higher levels of H
2
O
2
. Furthermore, colonization of germ-free mice with dysbiotic microbiota from mice or patients with IBD resulted in increased H
2
O
2
production compared with healthy controls. Collectively, these data suggest that IECs are capable of H
2
O
2
production during chronic inflammation and dysbiotic states. Our results provide insight into luminal production of H
2
O
2
by IECs as a read-out of innate defense by the mucosa.
Lamina propria phagocytes are key mediators of inflammatory bowel disease (IBD). We aimed to understand the transcriptomic and functional differences in these cells based on location, disease type, ...inflammation state, and medication use in patients with IBD.
Phagocytic immune cells in the lamina propria, as defined by the marker CD11b, were isolated from 54 unique patients (n = 111 gut mucosal biopsies). We performed flow cytometry for cell phenotyping (n = 30) and RNA sequencing with differential gene expression analysis (n = 58). We further cultured these cells in vitro and exposed them to janus kinase inhibitors to measure cytokine output (n = 27). Finally, we matched patient genomic data to our RNA sequencing data to perform candidate gene expression quantitative trait locus analysis (n = 34).
We found distinct differences in gene expression between CD11b+ cells from the colon vs ileum, as well as in different inflammatory states and, to a lesser degree, IBD types (Crohn’s disease or ulcerative colitis). These genes mapped to targetable immune pathways and metabolic and cancer pathways. We further explored the janus kinase-signal transducer and activator of transcription pathway, which was upregulated across many comparisons including in biopsies from anti–tumor necrosis factor refractory patients. We found that isolated CD11b+ cells treated with janus kinase inhibitors had decreased secretion of cytokines tumor necrosis factorα and interleukin-8 (P ≤ .05). We also found 3 genetic variants acting as expression quantitative trait loci (P ≤ .1) within our CD11b+ data set.
Lamina propria phagocytes from IBD mucosa provide pathogenetic clues on the nature of treatment refractoriness and inform new targets for therapy.
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