RESUMO
Allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains a potential curative option for treating a variety of hematologic diseases, but acute and chronic graft-versus-host disease (GVHD) remain major barriers limiting efficacy. Acute gut GVHD occurs with marked increases in proinflammatory cytokines (including TNF and IL-6), which we recently demonstrated was exacerbated in obesity resulting in severe gastrointestinal pathology. Given the pleiotropic and overlapping effects of these 2 cytokines, we assessed the impact of dual TNF and IL-6R blockade on GVHD as well as graft-versus tumor (GVT) effects in different mouse GVHD models. Early administration of combined blockade resulted in greater protection and survival from acute gut GVHD compared with single blockade regimens and even development of later chronic skin GVHD. Importantly, double cytokine blockade preserved GVT effects reinforcing that GVT and GVHD can be delineated and may result in greater efficacy in allo-HSCT.
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Anti-Inflamatórios/uso terapêutico , Doença Enxerto-Hospedeiro/prevenção & controle , Transplante de Células-Tronco Hematopoéticas , Receptores de Interleucina-6/antagonistas & inibidores , Inibidores do Fator de Necrose Tumoral/uso terapêutico , Animais , Anticorpos Monoclonais/uso terapêutico , Modelos Animais de Doenças , Etanercepte/uso terapêutico , Feminino , Efeito Enxerto vs Tumor/efeitos dos fármacos , Transplante de Células-Tronco Hematopoéticas/métodos , Humanos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Transplante Homólogo/métodosRESUMO
BACKGROUND AND AIM: Inflammatory bowel diseases (IBD) have been associated with increased risk of cardiovascular events. We aimed to investigate the outcomes of myocardial infarction (MI) in patients with IBD. METHODS: We performed a cross-sectional study utilizing data from the Nationwide Inpatient Sample from the years 1998 to 2010. ICD-9-CM codes were used to identify patients with Crohn's disease (CD) (555.X), ulcerative colitis (UC) (556.X), and acute MI (410.X). Outcomes in patients with MI with and without IBD were compared. Univariate analysis was performed. Multivariate logistic regression was used to determine the effect of UC and CD on in-hospital MI mortality after adjusting for confounders. RESULTS: A total of 2,629,161 MI, 3,607 UC and 3784 CD patients were analyzed. UC (odds ratio [OR], 1.12; 95% CI 0.98-1.29) and CD (OR 0.99; 95% CI 0.86-1.15) did not affect in-hospital mortality in patients with MI. There was no difference between in-hospital mortality in patients with MI with or without UC (7.75% vs. 7.05%; p = 0.25) or in patients with MI with or without CD (6.50% vs. 6.59%; p = 0.87). The length of stay (LOS) was higher in IBD patients and total charges were statistically higher in patients with UC as compared to non-IBD patients ($65,182 vs. $53,542; p < 0.001). CONCLUSIONS: This study shows that IBD does not impact in-hospital mortality from MI. However, patients with MI with IBD have longer LOS. Patients with UC have higher total hospitalization charges than patients with MI without IBD. Further prospective studies are needed to assess the outcomes of MI in IBD patients.
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Colite Ulcerativa/epidemiologia , Doença de Crohn/epidemiologia , Tempo de Internação , Infarto do Miocárdio/epidemiologia , Idoso , Colite Ulcerativa/economia , Colite Ulcerativa/mortalidade , Colite Ulcerativa/terapia , Doença de Crohn/economia , Doença de Crohn/mortalidade , Doença de Crohn/terapia , Estudos Transversais , Bases de Dados Factuais , Preços Hospitalares , Custos Hospitalares , Mortalidade Hospitalar , Humanos , Pacientes Internados , Infarto do Miocárdio/economia , Infarto do Miocárdio/mortalidade , Infarto do Miocárdio/terapia , Medição de Risco , Fatores de Risco , Fatores de Tempo , Estados UnidosRESUMO
In patients with Crohn's disease, perianal fistulas recur frequently, causing substantial morbidity. We performed a 12-patient, 6-month, phase 1 trial to determine whether autologous mesenchymal stem cells, applied in a bioabsorbable matrix, can heal the fistula. Fistula repair was not associated with any serious adverse events related to mesenchymal stem cells or plug placement. At 6 months, 10 of 12 patients (83%) had complete clinical healing and radiographic markers of response. We found placement of mesenchymal stem cell-coated matrix fistula plugs in 12 patients with chronic perianal fistulas to be safe and lead to clinical healing and radiographic response in 10 patients. ClinicalTrials.gov Identifier: NCT01915927.
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Doença de Crohn/complicações , Fístula Cutânea/terapia , Transplante de Células-Tronco Mesenquimais , Fístula Retal/terapia , Implantes Absorvíveis/efeitos adversos , Adolescente , Adulto , Fístula Cutânea/etiologia , Feminino , Humanos , Masculino , Transplante de Células-Tronco Mesenquimais/efeitos adversos , Pessoa de Meia-Idade , Fístula Retal/etiologia , Transplante Autólogo , Resultado do Tratamento , Cicatrização , Adulto JovemRESUMO
BACKGROUND: While monoclonal antibodies against tumor necrosis factor-α (TNFα) are effective in treating Crohn's disease (CD), approximately one-third of patients lose response. The mechanisms underlying this loss of response remain elusive. AIM: We sought to determine if novel biological pathways, including TNFα-independent inflammatory pathways, emerge in those with loss of response to anti-TNFα. METHODS: Using RNA microarray technology in 28 patients with CD, we examined the colonic gene expression differences between those with active inflammation in the setting of loss of response to TNFα-antagonist therapy ("loss of responders") compared to anti-TNFα naïve patients with active inflammation and those on anti-TNF therapy in disease remission. Pathway enrichment analyses were performed. RESULTS: We found that colonic expression of chemokines known to drive inflammation (CXCL20, CXCL9, and CXCL10) was elevated in those with loss of response compared to those in remission. Expression of genes critical to modulating oxidative stress burden (DUOX2, DUOXA2, and NOS2) was also elevated. Additionally, MMP3, MMP1, and MMP12 were elevated in those with continued inflammation. Gene enrichment analysis revealed that loss of responders exhibited dysregulation in the cysteine and methionine metabolism pathway, suggesting alteration in oxidative stress burden. There were no differences in genes or pathways between loss of responders and those who were TNFα-naïve. However, loss of response occurred despite the ability of anti-TNFα therapy to normalize APO gene expression. CONCLUSION: Our analyses suggest that loss of response to anti-TNFα is not driven by the emergence of pathways that bypass the action or induce resistance to anti-TNFα therapy.
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Anti-Inflamatórios/uso terapêutico , Doença de Crohn/tratamento farmacológico , Tolerância a Medicamentos/fisiologia , Fármacos Gastrointestinais/uso terapêutico , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Adalimumab/uso terapêutico , Doença de Crohn/metabolismo , Doença de Crohn/patologia , Feminino , Humanos , Infliximab/uso terapêutico , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Masculino , Estresse Oxidativo/fisiologia , Indução de Remissão , Adulto JovemRESUMO
PURPOSE OF REVIEW: There is a need for novel therapies for inflammatory bowel diseases (IBDs) that are well tolerated and effective. Currently, mesenchymal stem/stromal cells (MSCs) are being investigated in clinical trials for treatment of IBD. In this review, we update the recently published studies with an emphasis on the long-term efficacy of MSC therapy for IBD. RECENT FINDINGS: A cumulative body of data, including a recent phase III randomized controlled trial demonstrated excellent fistula healing in patients with refractory Crohn's perianal fistulae treated via local injections of MSCs and with a good safety profile. Follow-up studies suggest long-term efficacy of MSC therapy for complex perianal Crohn's disease fistulae; however, the efficacy decreases over time and may necessitate repeat treatment. Systemic (intravenous) therapy for luminal IBD offers a relatively well tolerated alternative but its efficacy remains unclear. SUMMARY: Recent studies demonstrate that MSCs are well tolerated and have an excellent short-term efficacy for the management of refractory fistulizing perianal Crohn's disease. The current data suggest that its influence may 'wear off' over time. More data on larger number of patients with longer duration of follow-up in the setting of a randomized placebo controlled trial are needed to confirm these promising results. For luminal IBD, there is a need for more mechanistic studies in representative preclinical murine models, and the results of an ongoing phase III randomized controlled trial are eagerly awaited.
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Doenças Inflamatórias Intestinais/terapia , Transplante de Células-Tronco Mesenquimais/métodos , Animais , Modelos Animais de Doenças , Humanos , Doenças Inflamatórias Intestinais/fisiopatologia , Células-Tronco Mesenquimais/fisiologiaRESUMO
BACKGROUND & AIMS: After allogeneic transplantation, murine stem cells (SCs) for interstitial cells of Cajal (ICCs), electrical pacemaker, and neuromodulator cells of the gut, were incorporated into gastric ICC networks, indicating in vivo immunosuppression. Immunosuppression is characteristic of bone marrow- and other non-gut-derived mesenchymal stem cells (MSCs), which are emerging as potential therapeutic agents against autoimmune diseases, including inflammatory bowel disease. Therefore, we investigated whether gut-derived ICC-SCs could also mitigate experimental colitis and studied the mechanisms of ICC-SC-mediated immunosuppression in relation to MSC-induced pathways. METHODS: Isolated ICC-SCs were studied by transcriptome profiling, cytokine assays, flow cytometry, mixed lymphocyte reaction, and T-cell proliferation assay. Mice with acute and chronic colitis induced by dextran sulfate sodium and T-cell transfer, respectively, were administered ICC-SCs intraperitoneally and evaluated for disease activity by clinical and pathological assessment and for ICC-SC homing by live imaging. RESULTS: Unlike strain-matched dermal fibroblasts, intraperitoneally administered ICC-SCs preferentially homed to the colon and reduced the severity of both acute and chronic colitis assessed by clinical and blind pathological scoring. ICC-SCs profoundly suppressed T-cell proliferation in vitro. Similar to MSCs, ICC-SCs strongly expressed cyclooxygenase 1/2 and basally secreted prostaglandin E2. Indomethacin, a cyclooxygenase inhibitor, countered the ICC-SC-mediated suppression of T-cell proliferation. In contrast, we found no role for regulatory T-cell-, programmed death receptor-, and transforming growth factor-ß-mediated mechanisms reported in MSCs; and transcriptome profiling did not support a relationship between ICC-SCs and MSCs. CONCLUSIONS: Murine ICC-SCs belong to a class different from MSCs and potently mitigate experimental colitis via prostaglandin E2-mediated immunosuppression.
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Colite/prevenção & controle , Colo , Dinoprostona/metabolismo , Imunidade Celular , Células Intersticiais de Cajal/transplante , Transplante de Células-Tronco , Transferência Adotiva , Animais , Proliferação de Células , Células Cultivadas , Colite/induzido quimicamente , Colite/imunologia , Colite/metabolismo , Colite/patologia , Colo/imunologia , Colo/metabolismo , Colo/patologia , Proteínas de Ligação a DNA/deficiência , Proteínas de Ligação a DNA/genética , Sulfato de Dextrana , Perfilação da Expressão Gênica , Marcadores Genéticos , Proteínas de Homeodomínio/genética , Hospedeiro Imunocomprometido , Células Intersticiais de Cajal/imunologia , Células Intersticiais de Cajal/metabolismo , Ativação Linfocitária , Camundongos Endogâmicos C57BL , Camundongos Knockout , Linfócitos T/imunologia , Linfócitos T/metabolismo , Linfócitos T/transplante , Fatores de TempoRESUMO
The role of GLI1 in pancreatic tumor initiation promoting the progression of preneoplastic lesions into tumors is well established. However, its function at later stages of pancreatic carcinogenesis remains poorly understood. To address this issue, we crossed the gli1 knock-out (GKO) animal with cre-dependent pancreatic activation of oncogenic kras concomitant with loss of the tumor suppressor tp53 (KPC). Interestingly, in this model, GLI1 played a tumor-protective function, where survival of GKO/KPC mice was reduced compared with KPC littermates. Both cohorts developed pancreatic cancer without significant histopathological differences in survival studies. However, analysis of mice using ultrasound-based imaging at earlier time points showed increased tumor burden in GKO/KPC mice. These animals have larger tumors, decreased body weight, increased lactate dehydrogenase production, and severe leukopenia. In vivo and in vitro expression studies identified FAS and FAS ligand (FASL) as potential mediators of this phenomenon. The FAS/FASL axis, an apoptotic inducer, plays a role in the progression of pancreatic cancer, where its expression is usually lost or significantly reduced in advanced stages of the disease. Chromatin immunoprecipitation and reporter assays identified FAS and FASL as direct targets of GLI1, whereas GKO/KPC mice showed lower levels of this ligand compared with KPC animals. Finally, decreased levels of apoptosis were detected in tumor tissue in the absence of GLI1 by TUNEL staining. Together, these findings define a novel pathway regulated by GLI1 controlling pancreatic tumor progression and provide a new theoretical framework to help with the design and analysis of trials targeting GLI1-related pathways.
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Fatores de Transcrição Kruppel-Like/antagonistas & inibidores , Neoplasias Pancreáticas/patologia , Animais , Progressão da Doença , Humanos , Camundongos , Camundongos Knockout , Proteína GLI1 em Dedos de ZincoRESUMO
BACKGROUND & AIMS: Little is known about progression of ischemic colitis (IC) among unselected patients. We aimed to estimate the incidence, risk factors, and natural history of IC in a population-based cohort in Olmsted County, Minnesota. METHODS: We performed a retrospective population-based cohort and nested case-control study of IC. Each IC case was matched to 2 controls from the same population on the basis of sex, age, and closest registration number. Conditional logistic regression, the Kaplan-Meier method, and proportional hazards regression were used to assess comorbidities, estimate survival, and identify characteristics associated with survival, respectively. RESULTS: Four hundred forty-five county residents (median age, 71.6 years; 67% female) were diagnosed with IC from 1976 through 2009 and were matched with 890 controls. The age-adjusted and sex-adjusted incidence rates of IC nearly quadrupled from 6.1 cases/100,000 person-years in 1976-1980 to 22.9/100,000 in 2005-2009. The odds for IC were significantly higher among subjects with atherosclerotic diseases; odds ratios ranged from 2.6 for individuals with coronary disease to 7.9 for individuals with peripheral vascular disease. Of IC cases, 59% survived for 5 years (95% confidence interval, 54%-64%), compared with 90% of controls (95% confidence interval, 88%-92%). Age >40 years, male sex, right-sided colon involvement, concomitant small bowel involvement, and chronic obstructive pulmonary disease were all independently associated with mortality (P < .05). CONCLUSIONS: The incidence of IC increased during the past 3 decades in a population-based cohort in Minnesota. IC typically presents in older patients with multiple comorbidities and is associated with high in-hospital mortality (11.5%) and rates of surgery (17%).
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Colite Isquêmica/epidemiologia , Colite Isquêmica/patologia , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Estudos de Coortes , Comorbidade , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Minnesota/epidemiologia , Estudos Retrospectivos , Fatores de Risco , Análise de Sobrevida , Resultado do Tratamento , Adulto JovemRESUMO
Inducible gene expression, which requires chromatin remodeling on gene promoters, underlies the epigenetically inherited differentiation program of most immune cells. However, chromatin-mediated mechanisms that underlie these events in T regulatory cells remain to be fully characterized. Here, we report that inducibility of FOXP3, a key transcription factor for the development of T regulatory cells, depends upon Kruppel-like factor 10 (KLF10) interacting with two antagonistic histone-modifying systems. We utilized chromatin immunoprecipitation, genome-integrated reporter assays, and functional domain KLF10 mutant proteins, to characterize reciprocal interactions between this transcription factor and either the Sin3-histone deacetylase complex or the histone acetyltransferase, p300/CBP-associated factor (PCAF). We characterize a Sin3-interacting repressor domain on the NH2 terminus of KLF10, which works to limit the activating function of this transcription factor. Indeed, inactivation of this Sin3-interacting domain renders KLF10 able to physically associate with PCAF as to induce FOXP3 gene transcription. We show that this biochemical data derived from studying our genome-integrated reporter cell system are recapitulated in primary murine lymphocytes. Collectively, these results advance our understanding of how a single transcription factor, namely KLF10, functions as a toggle to integrate antagonistic signals regulating FOXP3 and, thus, immune activation.
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Colite/enzimologia , Colo/enzimologia , Fatores de Transcrição de Resposta de Crescimento Precoce/metabolismo , Fatores de Transcrição Forkhead/metabolismo , Fatores de Transcrição Kruppel-Like/metabolismo , Complexo Correpressor Histona Desacetilase e Sin3/metabolismo , Linfócitos T Reguladores/enzimologia , Fatores de Transcrição de p300-CBP/metabolismo , Animais , Sítios de Ligação , Montagem e Desmontagem da Cromatina , Colite/induzido quimicamente , Colite/genética , Colite/imunologia , Colo/imunologia , Sulfato de Dextrana , Modelos Animais de Doenças , Fatores de Transcrição de Resposta de Crescimento Precoce/química , Fatores de Transcrição de Resposta de Crescimento Precoce/deficiência , Fatores de Transcrição de Resposta de Crescimento Precoce/genética , Epigênese Genética , Fatores de Transcrição Forkhead/genética , Humanos , Células Jurkat , Fatores de Transcrição Kruppel-Like/química , Fatores de Transcrição Kruppel-Like/deficiência , Fatores de Transcrição Kruppel-Like/genética , Camundongos , Camundongos Knockout , Modelos Moleculares , Mutação , Regiões Promotoras Genéticas , Conformação Proteica , Domínios e Motivos de Interação entre Proteínas , Transdução de Sinais , Complexo Correpressor Histona Desacetilase e Sin3/química , Linfócitos T Reguladores/imunologia , Transfecção , Regulação para CimaRESUMO
Mesenchymal stem cells (MSCs) are novel therapeutics for the treatment of Crohn's disease. However, their mechanism of action is unclear, especially in disease-relevant chronic models of inflammation. Thus, we used SAMP-1/YitFc (SAMP), a chronic and spontaneous murine model of small intestinal inflammation, to study the therapeutic effects and mechanism of action of human bone marrow-derived MSCs (hMSC). hMSC dose-dependently inhibited naïve T lymphocyte proliferation via prostaglandin E2 (PGE2) secretion and reprogrammed macrophages to an anti-inflammatory phenotype. We found that the hMSCs promoted mucosal healing and immunologic response early after administration in SAMP when live hMSCs are present (until day 9) and resulted in a complete response characterized by mucosal, histological, immunologic, and radiological healing by day 28 when no live hMSCs are present. hMSCs mediate their effect via modulation of T cells and macrophages in the mesentery and mesenteric lymph nodes (mLN). Sc-RNAseq confirmed the anti-inflammatory phenotype of macrophages and identified macrophage efferocytosis of apoptotic hMSCs as a mechanism that explains their long-term efficacy. Taken together, our findings show that hMSCs result in healing and tissue regeneration in a chronic model of small intestinal inflammation and despite being short-lived, exert long-term effects via sustained anti-inflammatory programming of macrophages via efferocytosis.
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BACKGROUND: Early identification of Crohn's disease (CD) patients at risk for complications could enable targeted surgical referral, but routine magnetic resonance enterography (MRE) has not been definitively correlated with need for surgery. Our objective was to identify computer-extracted image (radiomic) features from MRE associated with risk of surgery in CD and combine them with clinical and radiological assessments to predict time to intervention. METHODS: This was a retrospective single-center pilot study of CD patients who had an MRE within 3 months prior to initiating medical therapy. Radiomic features were extracted from annotated terminal ileum regions on MRE and combined with clinical variables and radiological assessment (via Simplified Magnetic Resonance Index of Activity scoring for wall thickening, edema, fat stranding, ulcers) in a random forest classifier. The primary endpoint was high- and low-risk groups based on need for surgery within 1 year of MRE. The secondary endpoint was time to surgery after treatment. RESULTS: Eight radiomic features capturing localized texture heterogeneity within the terminal ileum were significantly associated with risk of surgery within 1 year of treatment (P < .05); yielding a discovery cohort area under the receiver-operating characteristic curve of 0.67 (n = 50) and validation cohort area under the receiver-operating characteristic curve of 0.74 (n = 23). Kaplan-Meier analysis of radiomic features together with clinical variables and Simplified Magnetic Resonance Index of Activity scores yielded the best hazard ratio of 4.13 (P = (7.6 × 10-6) and concordance index of 0.71 in predicting time to surgery after MRE. CONCLUSIONS: Radiomic features on MRE may be associated with risk of surgery in CD, and in combination with clinicoradiological scoring can yield an accurate prognostic model for time to surgery.
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Doença de Crohn , Humanos , Doença de Crohn/tratamento farmacológico , Projetos Piloto , Estudos Retrospectivos , Íleo/patologia , Imageamento por Ressonância Magnética/métodosRESUMO
Background and aims: Major clinical manifestations of Wilson disease (WD) are related to copper accumulation in the liver and the brain, and little is known about other tissues involvement in metabolic changes in WD. In vitro studies suggested that the loss of intestinal ATP7B could contribute to metabolic dysregulation in WD. We tested this hypothesis by evaluating gut microbiota and lipidome in two mouse models of WD and by characterizing a new mouse model with a targeted deletion of Atp7b in intestine. Methods: Cecal content 16S sequencing and untargeted hepatic and plasma lipidome analyses in the Jackson Laboratory toxic-milk and the Atp7b null global knockout mouse models of WD were profiled and integrated. Intestine-specific Atp7b knockout mice ( Atp7b ΔIEC ) was generated using B6.Cg-Tg(Vil1-cre)997Gum/J mice and Atp7b Lox/Lox mice, and characterized using targeted lipidome analysis following a high-fat diet challenge. Results: Gut microbiota diversity was reduced in animal models of WD. Comparative prediction analysis revealed amino acid, carbohydrate, and lipid metabolism functions to be dysregulated in the WD gut microbial metagenome. Liver and plasma lipidomic profiles showed dysregulated tri- and diglyceride, phospholipid, and sphingolipid metabolism in WD models. When challenged with a high-fat diet, Atp7b ΔIEC mice exhibited profound alterations to fatty acid desaturation and sphingolipid metabolism pathways as well as altered APOB48 distribution in intestinal epithelial cells. Conclusion: Coordinated changes of gut microbiome and lipidome analyses underlie systemic metabolic manifestations in murine WD. Intestine-specific ATP7B deficiency affected both intestinal and systemic response to a high-fat challenge. WD is a systemic disease in which intestinal-specific ATP7B loss and diet influence phenotypic presentations.
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BACKGROUND: The clinical manifestations of Wilson disease (WD) are related to copper accumulation in the liver and the brain, but little is known about other tissue involvement regarding metabolic changes in WD. In vitro studies suggested that the loss of intestinal ATP7B affects metabolic dysregulation in WD. We tested this hypothesis by evaluating the gut microbiota and lipidome in 2 mouse models of WD and by characterizing a new mouse model with a targeted deletion of Atp7b in the intestine. METHODS: Cecal content 16S sequencing and untargeted hepatic and plasma lipidome analyses in the Jackson Laboratory toxic-milk and the Atp7b null global knockout mouse models of WD were profiled and integrated. Intestine-specific Atp7b knockout mice (Atp7bΔIEC) were generated and characterized using targeted lipidome analysis following a high-fat diet challenge. RESULTS: Gut microbiota diversity was reduced in animal models of WD. Comparative prediction analysis revealed amino acid, carbohydrate, and lipid metabolism functions to be dysregulated in the WD gut microbial metagenome. Liver and plasma lipidomic profiles showed dysregulated triglyceride and diglyceride, phospholipid, and sphingolipid metabolism in WD models. However, Atp7bΔIEC mice did not show gut microbiome differences compared to wild type. When challenged with a high-fat diet, Atp7bΔIEC mice exhibited profound alterations to fatty acid desaturation and sphingolipid metabolism pathways as well as altered APOB48 distribution in intestinal epithelial cells. CONCLUSIONS: Gut microbiome and lipidome underlie systemic metabolic manifestations in murine WD. Intestine-specific ATP7B deficiency affected both intestinal and systemic response to a high-fat challenge but not the microbiome profile, at least at early stages. WD is a systemic disease in which intestinal-specific ATP7B loss and diet influence the phenotype and the lipidome profile.
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Degeneração Hepatolenticular , Animais , Camundongos , Degeneração Hepatolenticular/genética , Metabolismo dos Lipídeos/genética , Modelos Animais de Doenças , Esfingolipídeos , IntestinosRESUMO
Bystander activation of memory T cells occurs via cytokine signaling alone in the absence of T cell receptor (TCR) signaling and provides a means of amplifying T cell effector responses in an antigen-nonspecific manner. While the role of Programmed Cell Death Protein 1 (PD-1) on antigen-specific T cell responses is extensively characterized, its role in bystander T cell responses is less clear. We examined the role of the PD-1 pathway during human and mouse non-antigen-specific memory T cell bystander activation and observed that PD-1+ T cells demonstrated less activation and proliferation than activated PD-1- populations in vitro. Higher activation and proliferative responses were also observed in the PD-1- memory population in both mice and patients with cancer receiving high-dose IL-2, mirroring the in vitro phenotypes. This inhibitory effect of PD-1 could be reversed by PD-1 blockade in vivo or observed using memory T cells from PD-1-/- mice. Interestingly, increased activation through abrogation of PD-1 signaling in bystander-activated T cells also resulted in increased apoptosis due to activation-induced cell death (AICD) and eventual T cell loss in vivo. These results demonstrate that the PD-1/PD-Ligand 1 (PD-L1) pathway inhibited bystander-activated memory T cell responses but also protected cells from AICD.
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Ativação Linfocitária , Receptor de Morte Celular Programada 1 , Humanos , Animais , Camundongos , Citocinas , Células T de Memória , FenótipoRESUMO
Objective: Mesenchymal stem cells (MSCs) are novel therapeutics for treatment of Crohn's disease. However, their mechanism of action is unclear, especially in disease-relevant chronic models of inflammation. Thus, we used SAMP-1/YitFc, a chronic and spontaneous murine model of small intestinal inflammation, to study the therapeutic effect and mechanism of human bone marrow-derived MSCs (hMSC). Design: hMSC immunosuppressive potential was evaluated through in vitro mixed lymphocyte reaction, ELISA, macrophage co-culture, and RT-qPCR. Therapeutic efficacy and mechanism in SAMP were studied by stereomicroscopy, histopathology, MRI radiomics, flow cytometry, RT-qPCR, small animal imaging, and single-cell RNA sequencing (Sc-RNAseq). Results: hMSC dose-dependently inhibited naïve T lymphocyte proliferation in MLR via PGE 2 secretion and reprogrammed macrophages to an anti-inflammatory phenotype. hMSC promoted mucosal healing and immunologic response early after administration in SAMP model of chronic small intestinal inflammation when live hMSCs are present (until day 9) and resulted in complete response characterized by mucosal, histological, immunologic, and radiological healing by day 28 when no live hMSCs are present. hMSC mediate their effect via modulation of T cells and macrophages in the mesentery and mesenteric lymph nodes (mLN). Sc-RNAseq confirmed the anti-inflammatory phenotype of macrophages and identified macrophage efferocytosis of apoptotic hMSCs as a mechanism of action that explains their long-term efficacy. Conclusion: hMSCs result in healing and tissue regeneration in a chronic model of small intestinal inflammation. Despite being short-lived, exert long-term effects via macrophage reprogramming to an anti-inflammatory phenotype. Data Transparency Statement: Single-cell RNA transcriptome datasets are deposited in an online open access repository 'Figshare' (DOI: https://doi.org/10.6084/m9.figshare.21453936.v1 ).
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BACKGROUND: The study of intestinal microbiota has been revolutionised by the use of molecular methods, including terminal restriction fragment length polymorphism (T-RFLP) analysis. Microbiota studies of Crohn's disease patients have examined samples from stool or from the neoterminal ileum with a standard biopsy forceps, which could be contaminated by colonic bacteria when the forceps passes through the colonoscope channel. OBJECTIVE: To determine whether sheathed biopsy forceps are able to obtain terminal ileal microbiota samples with less colonic bacterial contamination compared with unsheathed (standard) biopsy forceps. DESIGN: Prospective randomised single-centre study. PATIENTS AND METHODS: Four (paired) biopsy specimens were obtained from adjacent locations in the terminal ileum using the sheathed and standard forceps of 27 consecutive subjects undergoing colonoscopy and the microbiota were characterised using T-RFLP. The Bray-Curtis similarity index between samples (sheathed vs unsheathed forceps) was calculated within patients and significant differences were tested for across all patients. RESULTS: There was not a significant difference in the microbial diversity of samples obtained using sheathed versus unsheathed forceps. The difference in microbial diversity between patients was much greater than the variability within patients by proximal versus distal site or by forceps type. LIMITATIONS: T-RFLP is based on PCR amplification, so it is not always sensitive to rare bacterial species. CONCLUSION: Standard unsheathed forceps appear to be sufficient for microbiota sample collection from the terminal ileum.
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Bactérias/genética , Biópsia/instrumentação , DNA Bacteriano/análise , Íleo/microbiologia , Metagenoma , Instrumentos Cirúrgicos/normas , Colonoscópios , Colonoscopia , Humanos , Íleo/citologia , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Estudos Prospectivos , Reprodutibilidade dos TestesRESUMO
Crohn's disease (CD) is an inflammatory bowel disease with increasing incidence and prevalence worldwide. Perianal fistulas are seen in up to 26% of CD patients and are often refractory to medical therapy. Current treatments for CD perianal fistulas (pCD) include antibiotics, biologics, and for refractory cases, fecal diversion (FD) with ileostomy or colostomy. Mesenchymal stem/stromal cell therapy (MSCs) is a new modality that have shown efficacy in treating pCD. MSCs locally injected into pCD can lead to healing, and a phase III clinical trial (ADMIRE-CD) showed 66% clinical response, leading to approval of MSCs (Alofisel, Takeda) in the European Union. It is unclear if MSCs would be more cost-effective than the current standard of FD. We therefore developed a decision tree model to determine the cost-effectiveness of MSCs compared to FD for pCD. Our study showed that both autologous and allogeneic MSCs are more cost-effective than FD in an academic medical center and even in a worst-case scenario with 100% chance of all complications for MSCs treatment and 0% chance of complications for FD, both allogeneic and autologous MSCs are still cost saving compared to FD.