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1.
Nat Commun ; 11(1): 5005, 2020 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-33024109

RESUMO

Hypoxia-inducible factor 1α (HIF-1α) and HIF-2α are master transcription factors that regulate cellular responses to hypoxia, but the exact function in regulatory T (Treg) cells is controversial. Here, we show that Treg cell development is normal in mice with Foxp3-specific knockout (KO) of HIF-1α or HIF-2α. However, HIF-2α-KO (but not HIF-1α-KO) Treg cells are functionally defective in suppressing effector T cell-induced colitis and inhibiting airway hypersensitivity. HIF-2α-KO Treg cells have enhanced reprogramming into IL-17-secreting cells. We show crosstalk between HIF-2α and HIF-1α, and that HIF-2α represses HIF-1α expression. HIF-1α is upregulated in HIF-2α-KO Treg cells and further deletion of HIF-1α restores the inhibitory function of HIF-2α-KO Treg cells. Mice with Foxp3-conditional KO of HIF-2α are resistant to growth of MC38 colon adenocarcinoma and metastases of B16F10 melanoma. Together, these results indicate that targeting HIF-2α to destabilize Treg cells might be an approach for regulating the functional activity of Treg cells.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Linfócitos T Reguladores/fisiologia , Adenocarcinoma/genética , Adenocarcinoma/patologia , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Hiper-Reatividade Brônquica/genética , Linfócitos T CD4-Positivos/citologia , Diferenciação Celular , Reprogramação Celular , Colite/etiologia , Colite/patologia , Neoplasias do Colo/genética , Neoplasias do Colo/patologia , Feminino , Fatores de Transcrição Forkhead/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Interleucina-17/metabolismo , Masculino , Melanoma/genética , Melanoma/patologia , Camundongos Knockout , Linfócitos T Reguladores/metabolismo
2.
Anticancer Res ; 40(10): 5411-5416, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32988861

RESUMO

BACKGROUND: Patients with inflammatory bowel disease have markedly increased risk for developing colitis-associated colorectal adenocarcinoma (CAC). There is no established prognostic biomarker for CAC. MATERIALS AND METHODS: A retrospective study was performed on a cohort of 57 CACs. Expression of caudal type homeobox transcription factor 2 (CDX2) and YES-associated protein 1 (YAP1) expression was correlated with clinicodemographic and histopathological features. RESULTS: Neither YAP1 nor CDX2 expression alone was significantly associated with tumor invasion beyond the muscularis propria or lymph node status. However, a subgroup of CAC with double negativity for expression of YAP1 and CDX2 was more frequently found in younger patients, and more frequently associated with higher pathological tumor stage and nodal metastasis. Furthermore, a positive correlation between CDX2 and YAP1 expression was identified in CAC and sporadic colorectal adenocarcinoma. CONCLUSION: Our study demonstrates that double negativity for expression of YAP1 and CDX2 defines a subgroup of CAC with early onset and aggressive clinical features.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Fator de Transcrição CDX2/genética , Colite/genética , Neoplasias Colorretais/genética , Fatores de Transcrição/genética , Adenocarcinoma/complicações , Adenocarcinoma/genética , Adenocarcinoma/patologia , Adulto , Biomarcadores Tumorais/genética , Colite/complicações , Colite/patologia , Neoplasias Colorretais/complicações , Neoplasias Colorretais/patologia , Feminino , Humanos , Doenças Inflamatórias Intestinais/complicações , Doenças Inflamatórias Intestinais/genética , Doenças Inflamatórias Intestinais/patologia , Masculino , Pessoa de Meia-Idade , Prognóstico
3.
Anticancer Res ; 40(10): 5457-5462, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32988867

RESUMO

BACKGROUND/AIM: Several studies have found elevated soluble CD40 Ligand (sCD40L) in the serum of patients with malignancies as well as those with inflammatory bowel disease (IBD). Our goal was to determine the possible causal role of sCD40L in colitis-associated colorectal cancer (CAC) by using the well-established azoxymethane/dextran sulfate sodium (AOM/DSS) protocol. MATERIALS AND METHODS: Twelve wild type (WT) and twelve TLR4 knock out (KO) female C57BL6 mice were divided into 4 experimental groups. Six WT and six TLR4 KO mice were treated with a single intraperitoneal dose (10 mg/kg of body weight) of AOM followed by three 7-day cycles of oral 2.5% DSS. The other two groups included 6 WT and 6 TLR4 KO mice that received only water and served as the control groups. The mice were sacrificed after 84 days. RESULTS: All mice in the AOM/DSS WT group developed CAC while all mice from the AOM/DSS TLR4 KO group were protected from CAC. We measured the serum and pathologic tissue levels of sCD40L with quantitative sandwich enzyme-linked immunoassay (ELISA) and found that serum sCD40L was significantly higher in wild-type mice that developed CAC compared to their healthy counterparts (wild-type and TLR-4 KO controls). In comparison, serum sCD40L levels were comparable between TLR-4 KO mice, which are protected from developing CAC, and their healthy counterparts (wild-type and TLR-4 KO controls). Of note, tissue levels of sCD40L were not affected by the development of CAC. CONCLUSION: Our findings point to the presence of an axis between TLR-4 and sCD40L, which may lead to decreased immunosurveillance and the subsequent development of colitis-associated cancer.


Assuntos
Ligante de CD40/genética , Colite/imunologia , Neoplasias Colorretais/induzido quimicamente , Receptor 4 Toll-Like/genética , Animais , Azoximetano/toxicidade , Colite/induzido quimicamente , Colite/genética , Colite/patologia , Neoplasias Colorretais/genética , Neoplasias Colorretais/imunologia , Neoplasias Colorretais/patologia , Sulfato de Dextrana/toxicidade , Modelos Animais de Doenças , Humanos , Imunidade Inata/genética , Camundongos , Camundongos Knockout
4.
Korean J Gastroenterol ; 76(3): 164-166, 2020 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-32969365

RESUMO

The World Health Organization has declared novel coronavirus disease 2019 (COVID-19) a global public health emergency. Although respiratory symptoms predominate in COVID-19, thrombosis can occur in patients with COVID-19. This paper reports a case of an 82-year-old female with a prior medical history of hypertension, diabetes presenting with fever and cough, and was diagnosed with COVID-19. The patient subsequently developed progressively worsening of abdominal distention, tenderness, and underwent emergent laparotomy. She was found to have a gangrenous colon. This case adds to the limited literature regarding the extrapulmonary complications of COVID-19.


Assuntos
Colite/diagnóstico , Infecções por Coronavirus/diagnóstico , Pneumonia Viral/diagnóstico , Trombose Venosa/diagnóstico , Abdome/diagnóstico por imagem , Abdome/cirurgia , Doença Aguda , Idoso de 80 Anos ou mais , Anticoagulantes/uso terapêutico , Betacoronavirus/isolamento & purificação , Colite/patologia , Infecções por Coronavirus/complicações , Infecções por Coronavirus/virologia , Feminino , Heparina/uso terapêutico , Humanos , Laparotomia , Necrose , Pandemias , Pneumonia Viral/complicações , Pneumonia Viral/virologia , Tomografia Computadorizada por Raios X , Trombose Venosa/complicações , Trombose Venosa/tratamento farmacológico
5.
Life Sci ; 261: 118473, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32971101

RESUMO

AIMS: Electroacupuncture (EA) at ST36 has been verified to ameliorate experimental acute colitis. However, the effect of EA on chronic colitis and its mechanism has not yet been explored. This study aimed to assess the protective effect of EA against chronic colitis and the related mechanisms. MAIN METHODS: Chronic colitis was induced by dextran sulfate sodium (DSS) in C57BL/6 mice, and EA was applied throughout the entire experiment. Colonic inflammation and intestinal barrier integrity were evaluated. Alterations in the gut microbiota were analyzed by 16S rRNA gene sequencing. The fecal microbiota transplantation (FMT) experiment was used to further confirm the effect of the gut microbiota on the barrier protective effect of EA. The potential molecular mechanisms were explored by western blotting. KEY FINDINGS: (1) EA lowered the disease activity index (DAI) and histological scores, decreased the levels of TNFα, IL1ß, IL6 and iNOS, and increased the IL10 level in DSS-induced chronic colitis. (2) EA upregulated the protein expression of ZO-1, Occludin, E-Cadherin and mucin2 (MUC2), reduced the apoptosis and proliferation of intestinal epithelial cells (IECs) and intestinal permeability. (3) EA enhanced the gut microbiota diversity and restored the community structure. (4) Both the low-frequency EA (LEA) FMT and high-frequency EA (HEA) FMT maintained the intestinal barrier integrity. (5) EA promoted activation of the mitogen activated protein kinase (MAPK) signaling pathway. SIGNIFICANCE: EA can relieve chronic experimental colitis, and this effect may depend on activation of the MAPK signaling pathway through modulation of the gut microbiota to preserve the intestinal barrier.


Assuntos
Colite/terapia , Eletroacupuntura , Microbioma Gastrointestinal , Intestinos/patologia , Animais , Colite/induzido quimicamente , Colite/metabolismo , Colite/patologia , Sulfato de Dextrana , Transplante de Microbiota Fecal , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Masculino , Camundongos Endogâmicos C57BL , Permeabilidade
6.
PLoS Pathog ; 16(8): e1008763, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32834002

RESUMO

The various sub-species of Salmonella enterica cause a range of disease in human hosts. The human-adapted Salmonella enterica serovar Typhi enters the gastrointestinal tract and invades systemic sites to cause enteric (typhoid) fever. In contrast, most non-typhoidal serovars of Salmonella are primarily restricted to gut tissues. Across Africa, invasive non-typhoidal Salmonella (iNTS) have emerged with an ability to spread beyond the gastrointestinal tract and cause systemic bloodstream infections with increased morbidity and mortality. To investigate this evolution in pathogenesis, we compared the genomes of African iNTS isolates with other Salmonella enterica serovar Typhimurium and identified several macA and macB gene variants unique to African iNTS. MacAB forms a tripartite efflux pump with TolC and is implicated in Salmonella pathogenesis. We show that macAB transcription is upregulated during macrophage infection and after antimicrobial peptide exposure, with macAB transcription being supported by the PhoP/Q two-component system. Constitutive expression of macAB improves survival of Salmonella in the presence of the antimicrobial peptide C18G. Furthermore, these macAB variants affect replication in macrophages and influence fitness during colonization of the murine gastrointestinal tract. Importantly, the infection outcome resulting from these macAB variants depends upon both the Salmonella Typhimurium genetic background and the host gene Nramp1, an important determinant of innate resistance to intracellular bacterial infection. The variations we have identified in the MacAB-TolC efflux pump in African iNTS may reflect evolution within human host populations that are compromised in their ability to clear intracellular Salmonella infections.


Assuntos
Transportadores de Cassetes de Ligação de ATP/genética , Proteínas de Bactérias/genética , Colite/patologia , Variação Genética , Macrófagos/imunologia , Salmonelose Animal/patologia , Salmonella typhimurium/imunologia , Transportadores de Cassetes de Ligação de ATP/metabolismo , Animais , Proteínas de Bactérias/metabolismo , Linhagem da Célula , Colite/induzido quimicamente , Colite/imunologia , Colite/microbiologia , Análise Mutacional de DNA , Modelos Animais de Doenças , Macrófagos/metabolismo , Macrófagos/microbiologia , Camundongos , Camundongos Endogâmicos C57BL , Salmonelose Animal/imunologia , Salmonelose Animal/microbiologia , Replicação Viral
7.
Nat Commun ; 11(1): 4286, 2020 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-32855403

RESUMO

Intracellular galectins are carbohydrate-binding proteins capable of sensing and repairing damaged lysosomes. As in the physiological conditions glycosylated moieties are mostly in the lysosomal lumen but not cytosol, it is unclear whether galectins reside in lysosomes, bind to glycosylated proteins, and regulate lysosome functions. Here, we show in gut epithelial cells, galectin-9 is enriched in lysosomes and predominantly binds to lysosome-associated membrane protein 2 (Lamp2) in a Asn(N)-glycan dependent manner. At the steady state, galectin-9 binding to glycosylated Asn175 of Lamp2 is essential for functionality of lysosomes and autophagy. Loss of N-glycan-binding capability of galectin-9 causes its complete depletion from lysosomes and defective autophagy, leading to increased endoplasmic reticulum (ER) stress preferentially in autophagy-active Paneth cells and acinar cells. Unresolved ER stress consequently causes cell degeneration or apoptosis that associates with colitis and pancreatic disorders in mice. Therefore, lysosomal galectins maintain homeostatic function of lysosomes to prevent organ pathogenesis.


Assuntos
Galectinas/metabolismo , Proteína 2 de Membrana Associada ao Lisossomo/metabolismo , Lisossomos/metabolismo , Pâncreas/patologia , Celulas de Paneth/patologia , Células Acinares/metabolismo , Células Acinares/patologia , Animais , Autofagia/fisiologia , Colite/metabolismo , Colite/patologia , Estresse do Retículo Endoplasmático , Galectinas/genética , Células HT29 , Humanos , Proteína 2 de Membrana Associada ao Lisossomo/genética , Lisossomos/genética , Lisossomos/patologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pâncreas/metabolismo , Pancreatite/metabolismo , Pancreatite/patologia , Celulas de Paneth/metabolismo
8.
Nat Commun ; 11(1): 4076, 2020 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-32796851

RESUMO

Group 3 innate lymphoid cells (ILC3) are an important regulator for immunity, inflammation and tissue homeostasis in the intestine, but how ILC3 activation is regulated remains elusive. Here we identify a new circular RNA (circRNA) circKcnt2 that is induced in ILC3s during intestinal inflammation. Deletion of circKcnt2 causes gut ILC3 activation and severe colitis in mice. Mechanistically, circKcnt2, as a nuclear circRNA, recruits the nucleosome remodeling deacetylase (NuRD) complex onto Batf promoter to inhibit Batf expression; this in turn suppresses Il17 expression and thereby ILC3 inactivation to promote innate colitis resolution. Furthermore, Mbd3-/-Rag1-/- and circKcnt2-/-Rag1-/- mice develop severe innate colitis following dextran sodium sulfate (DSS) treatments, while simultaneous deletion of Batf promotes colitis resolution. In summary, our data support a function of the circRNA circKcnt2 in regulating ILC3 inactivation and resolution of innate colitis.


Assuntos
Colite/imunologia , Colite/metabolismo , Linfócitos/metabolismo , Canais de Potássio Ativados por Sódio/metabolismo , RNA Circular/metabolismo , Animais , Colite/patologia , Proteínas de Ligação a DNA/genética , Modelos Animais de Doenças , Feminino , Proteínas de Homeodomínio/genética , Homeostase , Humanos , Imunidade Inata , Inflamação/imunologia , Inflamação/patologia , Intestinos/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos ICR , Camundongos Knockout , Canais de Potássio Ativados por Sódio/genética , RNA Circular/genética , RNA não Traduzido/genética , RNA não Traduzido/metabolismo , Fatores de Transcrição/genética
9.
PLoS One ; 15(7): e0236595, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32706816

RESUMO

Colorectal cancer (CRC) risk is influenced by host genetics, sex, and the gut microbiota. Using a genetically susceptible mouse model of CRC induced via inoculation with pathobiont Helicobacter spp. and demonstrating variable tumor incidence, we tested the ability of the Th17-enhancing commensal Candidatus Savagella, more commonly denoted as Segmented Filamentous Bacteria (SFB), to influence the incidence and severity of colitis-associated CRC in male and female mice. To document the composition of the gut microbiota during CRC development and identify taxa associated with disease, fecal samples were collected before and throughout disease development and characterized via 16S rRNA sequencing. While there were no significant SFB-dependent effects on disease incidence or severity, SFB was found to exert a sex-dependent protective effect in male mice. Furthermore, SFB stabilized the GM against Helicobacter-induced changes post-inoculation, resulting in a shift in disease association from Helicobacter spp. to Escherichia coli. These data support sex-dependent SFB-mediated effects on CRC risk, and highlight the complex community dynamics within the GM during exposure to inflammatory pathobionts.


Assuntos
Clostridiaceae/patogenicidade , Colite/patologia , Neoplasias Colorretais/patologia , Animais , Clostridiaceae/genética , Colite/complicações , Neoplasias Colorretais/etiologia , Modelos Animais de Doenças , Fezes/microbiologia , Feminino , Microbioma Gastrointestinal , Helicobacter/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Estadiamento de Neoplasias , RNA Ribossômico 16S/genética , RNA Ribossômico 16S/metabolismo , Proteína Smad3/deficiência , Proteína Smad3/genética
10.
PLoS One ; 15(7): e0235706, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32639988

RESUMO

During type 1 immune responses, CD4 T helper 1 (Th1) cells and CD8 T cells are activated via IL-12 and contribute to the elimination of intracellular pathogens through interferon gamma (IFNγ) production. In this study, we identified Placenta-specific 8 (Plac8) as a gene that is uniquely expressed in Th1 CD4 T cells relative to other CD4 T cell subsets and hypothesized that Plac8 may represent a novel therapeutic target in Th1 CD4 T cells. First, we determined that Plac8 mRNA in CD4 T cells was induced following IL-12 stimulation via an indirect route that required new protein synthesis. Upon evaluating the functional relevance of Plac8 expression in Th1 CD4 T cells, we discovered that Plac8 was important for suppressing IFNγ mRNA and protein production by CD4 T cells 24 hours after IL-12 stimulation, however Plac8 did not contribute to pathogenic CD4 T cell function during two models of intestinal inflammation. We also noted relatively high basal expression of Plac8 in CD8 T cells which could be further induced following IL-12 stimulation in CD8 T cells. Furthermore, Plac8 expression was important for establishing an optimal CD8 T cell response against influenza A virus via a T cell-intrinsic manner. Altogether, these results implicate Plac8 as a potential regulator of Th1 CD4 and CD8 T cell responses during Th1 T cell-driven inflammation.


Assuntos
Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Interferon gama/metabolismo , Proteínas/metabolismo , Animais , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Colite/imunologia , Colite/patologia , Modelos Animais de Doenças , Interferon gama/genética , Interleucina-12/farmacologia , Antígenos Comuns de Leucócito/genética , Antígenos Comuns de Leucócito/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/patologia , Proteínas/genética , RNA Mensageiro/metabolismo , Regulação para Cima/efeitos dos fármacos
11.
Arch Biochem Biophys ; 692: 108490, 2020 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-32721434

RESUMO

Ulcerative colitis is a condition characterised by the infiltration of leukocytes into the gastrointestinal wall. Leukocyte-MPO catalyses hypochlorous acid (HOCl) and hypothiocyanous acid (HOSCN) formation from chloride (Cl-) and thiocyanous (SCN-) anions, respectively. While HOCl indiscriminately oxidises biomolecules, HOSCN primarily targets low-molecular weight protein thiols. Oxidative damage mediated by HOSCN may be reversible, potentially decreasing MPO-associated host tissue destruction. This study investigated the effect of SCN- supplementation in a model of acute colitis. Female mice were supplemented dextran sodium sulphate (DSS, 3% w/v) in the presence of 10 mM Cl- or SCN- in drinking water ad libitum, or with salts (NaCl and NaSCN only) or water only (controls). Behavioural studies showed mice tolerated NaSCN and NaCl-treated water with water-seeking frequency. Ion-exchange chromatography showed increased fecal and plasma SCN- levels in thiocyanate supplemented mice; plasma SCN- reached similar fold-increase for smokers. Overall there was no difference in weight loss and clinical score, mucin levels, crypt integrity and extent of cellular infiltration between DSS/SCN- and DSS/Cl- groups. Neutrophil recruitment remained unchanged in DSS-treated mice, as assessed by fecal calprotectin levels. Total thiol and tyrosine phosphatase activity remained unchanged between DSS/Cl- and DSS/SCN- groups, however, colonic tissue showed a trend in decreased 3-chlorotyrosine (1.5-fold reduction, p < 0.051) and marked increase in colonic GCLC, the rate-limiting enzyme in glutathione synthesis. These data suggest that SCN- administration can modulate MPO activity towards a HOSCN-specific pathway, however, this does not alter the development of colitis within a DSS murine model.


Assuntos
Colite , Colo , Sulfato de Dextrana/toxicidade , Peroxidase/metabolismo , Tiocianatos/farmacologia , Animais , Colite/induzido quimicamente , Colite/tratamento farmacológico , Colite/enzimologia , Colite/patologia , Colo/enzimologia , Colo/patologia , Modelos Animais de Doenças , Feminino , Camundongos
12.
Nature ; 585(7826): 591-596, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32526765

RESUMO

Recent clinical and experimental evidence has evoked the concept of the gut-brain axis to explain mutual interactions between the central nervous system and gut microbiota that are closely associated with the bidirectional effects of inflammatory bowel disease and central nervous system disorders1-4. Despite recent advances in our understanding of neuroimmune interactions, it remains unclear how the gut and brain communicate to maintain gut immune homeostasis, including in the induction and maintenance of peripheral regulatory T cells (pTreg cells), and what environmental cues prompt the host to protect itself from development of inflammatory bowel diseases. Here we report a liver-brain-gut neural arc that ensures the proper differentiation and maintenance of pTreg cells in the gut. The hepatic vagal sensory afferent nerves are responsible for indirectly sensing the gut microenvironment and relaying the sensory inputs to the nucleus tractus solitarius of the brainstem, and ultimately to the vagal parasympathetic nerves and enteric neurons. Surgical and chemical perturbation of the vagal sensory afferents at the hepatic afferent level reduced the abundance of colonic pTreg cells; this was attributed to decreased aldehyde dehydrogenase (ALDH) expression and retinoic acid synthesis by intestinal antigen-presenting cells. Activation of muscarinic acetylcholine receptors directly induced ALDH gene expression in both human and mouse colonic antigen-presenting cells, whereas genetic ablation of these receptors abolished the stimulation of antigen-presenting cells in vitro. Disruption of left vagal sensory afferents from the liver to the brainstem in mouse models of colitis reduced the colonic pTreg cell pool, resulting in increased susceptibility to colitis. These results demonstrate that the novel vago-vagal liver-brain-gut reflex arc controls the number of pTreg cells and maintains gut homeostasis. Intervention in this autonomic feedback feedforward system could help in the development of therapeutic strategies to treat or prevent immunological disorders of the gut.


Assuntos
Encéfalo/citologia , Intestinos/citologia , Intestinos/inervação , Fígado/citologia , Fígado/inervação , Neurônios/fisiologia , Linfócitos T Reguladores/citologia , Linfócitos T Reguladores/imunologia , Vias Aferentes , Animais , Células Apresentadoras de Antígenos/imunologia , Colite/imunologia , Colite/metabolismo , Colite/patologia , Homeostase , Humanos , Intestinos/imunologia , Masculino , Camundongos , Ratos , Receptores Muscarínicos/metabolismo , Baço/citologia , Baço/imunologia , Nervo Vago/fisiologia
13.
Acta Cir Bras ; 35(4): e202000404, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32555936

RESUMO

PURPOSE: To analyze the effect of calcitriol treatment on acute colitis in an experimental rat model. METHODS: A total of 24 adult Sprague Dawley albino rats were randomly separated into 3 equal groups: control group (n:8), colitis group (n:8), calcitriol administered group (n:8). A single dose of acetic acid (1 ml of 4% solution) was administered intrarectally to induce colitis. Group 1 was given 1 ml/kg 0.9% NaCl intraperitoneally; rats belonging to Group 2 were administered calcitriol 1 µg/kg for 5 days. RESULTS: Plasma tumor necrosis factor alpha, Pentraxin 3, and malondialdehyde levels were significantly lower in the calcitriol administered colitis group than in the standard colitis group (p<0.01). In the Calcitriol group, there was a significant histological improvement in hyperemia, hemorrhage and necrotic areas in the epithelium compared to the placebo group (p <0.000). CONCLUSION: The findings suggest that calcitriol may be an agent that could be used in acute colitis treatment.


Assuntos
Anti-Inflamatórios/uso terapêutico , Calcitriol/uso terapêutico , Colite/tratamento farmacológico , Doença Aguda , Animais , Proteína C-Reativa/análise , Colite/sangue , Colite/patologia , Modelos Animais de Doenças , Peroxidação de Lipídeos , Masculino , Malondialdeído/sangue , Estresse Oxidativo/genética , Distribuição Aleatória , Ratos Sprague-Dawley , Valores de Referência , Reprodutibilidade dos Testes , Componente Amiloide P Sérico/análise , Resultado do Tratamento , Fator de Necrose Tumoral alfa/análise
14.
Am J Pathol ; 190(8): 1657-1666, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32380082

RESUMO

Increasingly, the ß-galactoside binding lectins, termed galectins, are being recognized as critical regulators of cell function and organismal homeostasis. Within the context of the mucosal surface, galectins are established regulators of innate and adaptive immune responses, microbial populations, and several critical epithelial functions, including cell migration, proliferation, and response to injury. However, given their complex tissue distribution and expression patterns, their role within specific processes remains poorly understood. We took a genetic approach to understand the role of endogenous galectin-9 (Gal-9), a mucosal galectin that has been linked to inflammatory bowel disease, within the context of the murine intestine. Gal-9-deficient (Gal9-/-, also known as Lgals9-/-) animals show increased sensitivity to chemically induced colitis and impaired proliferation in the setting of acute injury. Moreover, Gal9-/--derived enteroids showed impaired growth ex vivo. Consistent with a model in which endogenous Gal-9 controls epithelial growth and repair, Gal9-/- animals showed increased sensitivity to intestinal challenge in multiple models of epithelial injury, including acute irradiation injury and ectopic wound biopsies. Finally, regenerating crypts from patient biopsies showed increased expression of Gal-9, indicating these processes may be conserved in humans. Taken together, these studies implicate Gal-9 in the regulation of cellular proliferation and epithelial restitution after intestinal epithelial injury.


Assuntos
Colite/metabolismo , Colo/metabolismo , Galectinas/metabolismo , Mucosa Intestinal/metabolismo , Animais , Movimento Celular/fisiologia , Proliferação de Células/fisiologia , Colite/induzido quimicamente , Colite/genética , Colite/patologia , Colo/patologia , Galectinas/genética , Humanos , Mucosa Intestinal/patologia , Camundongos , Camundongos Knockout
15.
Toxicol Appl Pharmacol ; 400: 115075, 2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-32470352

RESUMO

NLRP3, one of the HSP-90 clients, has been defined as a critical component of IBD. In a rat model of DSS-induced colitis, we investigated the anti-inflammatory potential of the combined therapy with CP-456773 (CP), an NLRP3 inhibitor, and celastrol (CSR), an NF-κB inhibitor. Our results revealed that the CSR/CP combined therapy (CCCT) attenuated colon shortening, DAI and MDI in addition to improvement of the colonic histological picture. Moreover, the CCCT increased the antioxidant defense machinery of the colonic tissue and decreased MPO activity. Furthermore, the inflammation markers such as TNF-α and IL-6 were downregulated. These effects might be attributed to the inhibitory effect of CSR on the priming step of the NLRP3 inflammasome activation by interrupting NF-κB signalling and inhibition of HSP-90 (at the protein and mRNA levels) along with inhibitory effect of CP on the expression of the NLRP3. These latter effects resulted in decreased tissue expression and activity of the caspase-1 and repressing the subsequent release of the active forms of IL-1ß and IL-18, hence, the pyroptosis process is restrained. Additionally, the CCCT resulted in inducing autophagy by AMPK/mTOR-dependent mechanisms leading to the accumulation of BECN1 protein and a significant decrease in the levels of p62 SQSTM1. The inhibitory effect on HSP-90 in conjunction with induction of autophagy suggest increased autophagic degradation of NLRP3. This novel approach provides a basis for the clinical application of this combination in IBD treatment and might also be promising for the pharmacological intervention of other NLRP3 inflammasome-dependent inflammatory conditions.


Assuntos
Anti-Inflamatórios/farmacologia , Autofagia/efeitos dos fármacos , Colite/tratamento farmacológico , Proteínas de Choque Térmico HSP90/metabolismo , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/antagonistas & inibidores , Sulfonas/farmacologia , Triterpenos/farmacologia , Animais , Anti-Inflamatórios/administração & dosagem , Colite/induzido quimicamente , Colite/metabolismo , Colite/patologia , Citocinas/metabolismo , Sulfato de Dextrana/farmacologia , Modelos Animais de Doenças , Quimioterapia Combinada , Proteínas de Choque Térmico HSP90/sangue , Compostos Heterocíclicos de 4 ou mais Anéis/administração & dosagem , Compostos Heterocíclicos de 4 ou mais Anéis/uso terapêutico , Inflamassomos/efeitos dos fármacos , Inflamassomos/imunologia , Masculino , Ratos Sprague-Dawley , Sulfonas/administração & dosagem , Sulfonas/uso terapêutico , Triterpenos/administração & dosagem , Triterpenos/uso terapêutico
16.
Nat Commun ; 11(1): 2591, 2020 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-32444641

RESUMO

The intestine is a highly dynamic environment that requires tight control of the various inputs to maintain homeostasis and allow for proper responses to injury. It was recently found that the stem cell niche and epithelium is regenerated after injury by de-differentiated adult cells, through a process that gives rise to Sca1+ fetal-like cells and is driven by a transient population of Clu+ revival stem cells (revSCs). However, the molecular mechanisms that regulate this dynamic process have not been fully defined. Here we show that TNFAIP8 (also known as TIPE0) is a regulator of intestinal homeostasis that is vital for proper regeneration. TIPE0 functions through inhibiting basal Akt activation by the commensal microbiota via modulating membrane phospholipid abundance. Loss of TIPE0 in mice results in injury-resistant enterocytes, that are hyperproliferative, yet have regenerative deficits and are shifted towards a de-differentiated state. Tipe0-/- enterocytes show basal induction of the Clu+ regenerative program and a fetal gene expression signature marked by Sca1, but upon injury are unable to generate Sca-1+/Clu+ revSCs and could not regenerate the epithelium. This work demonstrates the role of TIPE0 in regulating the dynamic signaling that determines the injury response and enables intestinal epithelial cell regenerative plasticity.


Assuntos
Proteínas Reguladoras de Apoptose/metabolismo , Microbioma Gastrointestinal/fisiologia , Intestinos/citologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Animais , Proteínas Reguladoras de Apoptose/genética , Ataxina-1/metabolismo , Diferenciação Celular , Colite/induzido quimicamente , Colite/patologia , Enterócitos/patologia , Feminino , Técnicas de Silenciamento de Genes , Homeostase , Intestinos/irrigação sanguínea , Intestinos/patologia , Intestinos/efeitos da radiação , Isquemia/genética , Isquemia/patologia , Antígenos Comuns de Leucócito/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Lesões Experimentais por Radiação/patologia , Regeneração/fisiologia , Transdução de Sinais , Nicho de Células-Tronco , Células-Tronco/metabolismo
17.
Nat Commun ; 11(1): 1747, 2020 04 08.
Artigo em Inglês | MEDLINE | ID: mdl-32269263

RESUMO

Receptor interacting protein kinase 1 (RIPK1) regulates cell death and inflammatory responses downstream of TNFR1 and other receptors, and has been implicated in the pathogenesis of inflammatory and degenerative diseases. RIPK1 kinase activity induces apoptosis and necroptosis, however the mechanisms and phosphorylation events regulating RIPK1-dependent cell death signaling remain poorly understood. Here we show that RIPK1 autophosphorylation at serine 166 plays a critical role for the activation of RIPK1 kinase-dependent apoptosis and necroptosis. Moreover, we show that S166 phosphorylation is required for RIPK1 kinase-dependent pathogenesis of inflammatory pathologies in vivo in four relevant mouse models. Mechanistically, we provide evidence that trans autophosphorylation at S166 modulates RIPK1 kinase activation but is not by itself sufficient to induce cell death. These results show that S166 autophosphorylation licenses RIPK1 kinase activity to induce downstream cell death signaling and inflammation, suggesting that S166 phosphorylation can serve as a reliable biomarker for RIPK1 kinase-dependent pathologies.


Assuntos
Apoptose , Inflamação/metabolismo , Inflamação/patologia , Fosfosserina/metabolismo , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo , Alanina Transaminase/metabolismo , Animais , Células da Medula Óssea/citologia , Colite/patologia , Genótipo , Hepatite/patologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Macrófagos/metabolismo , Camundongos Endogâmicos C57BL , Mutação/genética , Neoplasias/patologia , Fosforilação , Sepse/patologia , Pele/patologia , Fator de Necrose Tumoral alfa
18.
Nat Commun ; 11(1): 1802, 2020 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-32286276

RESUMO

Inflammatory bowel disease patients have a greatly increased risk of developing colitis-associated colon cancer (CAC); however, the basis for inflammation-induced genetic damage requisite for neoplasia is unclear. Using three models of CAC, we find that sustained inflammation triggers 8-oxoguanine DNA lesions. Strikingly, antioxidants or iNOS inhibitors reduce 8-oxoguanine and polyps in CAC models. Because the mismatch repair (MMR) system repairs 8-oxoguanine and is frequently defective in colorectal cancer (CRC), we test whether 8-oxoguanine mediates oncogenesis in a Lynch syndrome (MMR-deficient) model. We show that microbiota generates an accumulation of 8-oxoguanine lesions in MMR-deficient colons. Accordingly, we find that 8-oxoguanine is elevated in neoplastic tissue of Lynch syndrome patients compared to matched untransformed tissue or non-Lynch syndrome neoplastic tissue. While antioxidants reduce 8-oxoguanine, they do not reduce CRC in Lynch syndrome models. Hence, microbe-induced oxidative/nitrosative DNA damage play causative roles in inflammatory CRC models, but not in Lynch syndrome models.


Assuntos
Colite/complicações , Colite/patologia , Neoplasias Colorretais/complicações , Neoplasias Colorretais/patologia , Dano ao DNA , Helicobacter pylori/fisiologia , Estresse Oxidativo , Polipose Adenomatosa do Colo/complicações , Polipose Adenomatosa do Colo/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Antioxidantes/farmacologia , Carcinogênese/efeitos dos fármacos , Carcinogênese/patologia , Colite/induzido quimicamente , Colite/microbiologia , Colo/efeitos dos fármacos , Colo/patologia , Neoplasias Colorretais/microbiologia , Neoplasias Colorretais Hereditárias sem Polipose/genética , Reparo do DNA/efeitos dos fármacos , Sulfato de Dextrana , Modelos Animais de Doenças , Disbiose/complicações , Disbiose/patologia , Escherichia coli/metabolismo , Feminino , Guanosina/análogos & derivados , Guanosina/metabolismo , Infecções por Helicobacter/complicações , Helicobacter pylori/efeitos dos fármacos , Humanos , Inflamação/complicações , Inflamação/patologia , Interleucina-10/deficiência , Interleucina-10/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Mutação/genética , Estresse Oxidativo/efeitos dos fármacos
19.
J Med Chem ; 63(8): 3881-3895, 2020 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-32223194

RESUMO

Exportin-1 (also named as CRM1) plays a prominent role in autoimmune disorders and has emerged as a potential therapeutic target for colitis. Here we report on the rational structure-based discovery of a small-molecule antagonist of exportin-1, LFS-829, with low-range nanomolar activities. The co-crystallographic structure, surface plasmon resonance binding assay, and cell-based phenotypic nuclear export functional assay validated that exportin-1 is a key target of LFS-829. Moreover, we demonstrated that the C528S mutation or the knockdown on exportin-1 can abolish the cellular activities of LFS-829. Strikingly, oral administration of LFS-829 can significantly reverse the pathological features of colitis model mice. We revealed that LFS-829 can attenuate dual NF-κB signaling and the Nrf2 cytoprotection pathway via targeting exportin-1 in colitis mice. Moreover, LFS-829 has a very low risk of cardiotoxicity and acute toxicity. Therefore, LFS-829 holds great promise for the treatment of colitis and may warrant translation for use in clinical trials.


Assuntos
Colite/tratamento farmacológico , Sistemas de Liberação de Medicamentos/métodos , Descoberta de Drogas/métodos , Hidrazinas/administração & dosagem , Carioferinas/antagonistas & inibidores , Receptores Citoplasmáticos e Nucleares/antagonistas & inibidores , Triazóis/administração & dosagem , Sequência de Aminoácidos , Animais , Colite/metabolismo , Colite/patologia , Relação Dose-Resposta a Droga , Células HEK293 , Humanos , Hidrazinas/química , Carioferinas/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Receptores Citoplasmáticos e Nucleares/metabolismo , Triazóis/química
20.
Biochem Biophys Res Commun ; 526(4): 1157-1163, 2020 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-32321642

RESUMO

The pathogenesis of inflammation bowel disease (IBD) involves exaggerated effector T cell responses and impaired regulatory T cell functions. We previously found that sauchinone (SAU) ameliorated experimental colitis via facilitating Th17 cell production of IL-10, but how SAU regulated Th17 cell differentiation remains unknown. MicroRNAs (miR) have been recognized as a crucial regulator of T cell biology and play a considerable role in IBD. Here, we demonstrated that SAU significantly suppressed miR-340 expression in Th17 cells, and enforced miR-340 expression abrogated SAU inhibition of Th17 differentiation. miR-340 itself was found to facilitate Th17 differentiation, especially the pathogenic "Th1-like" subset. In human IBD, miR-340 was intimately correlated with the disease severity. SAU markedly decreased miR-340 in the inflamed mucosa tissues from IBD patients. Scaffold/matrix-associated region-binding protein 1 (SMAR1) was identified as a target gene of miR-340. We revealed that blockade of miR-340 significantly reduced mucosal damage and Th17 responses in the lamina propria in a mouse colitis model. Our findings suggest that miR-340 negatively affects SAU inhibition of Th17 differentiation and might play a crucial role in the regulation of pathogenic "Th1-like" Th17 cell generation, which might serve as a novel therapeutic target of IBD.


Assuntos
Benzopiranos/farmacologia , Diferenciação Celular/efeitos dos fármacos , Dioxóis/farmacologia , Inflamação/imunologia , Doenças Inflamatórias Intestinais/genética , Doenças Inflamatórias Intestinais/imunologia , Intestinos/patologia , MicroRNAs/metabolismo , Células Th17/patologia , Sequência de Bases , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Colite/induzido quimicamente , Colite/imunologia , Colite/patologia , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Suscetibilidade a Doenças , Regulação para Baixo/efeitos dos fármacos , Fatores de Transcrição Forkhead/metabolismo , Humanos , MicroRNAs/genética , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Índice de Gravidade de Doença , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/imunologia , Células Th1/efeitos dos fármacos , Células Th1/patologia , Células Th17/efeitos dos fármacos , Células Th17/imunologia , Ácido Trinitrobenzenossulfônico , Regulação para Cima/efeitos dos fármacos
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