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1.
Nat Commun ; 11(1): 6343, 2020 12 11.
Artigo em Inglês | MEDLINE | ID: mdl-33311467

RESUMO

D-mannose is a monosaccharide approximately a hundred times less abundant than glucose in human blood. Previous studies demonstrated that supraphysiological levels of D-mannose inhibit tumour growth and stimulate regulatory T cell differentiation. It is not known whether D-mannose metabolism affects the function of non-proliferative cells, such as inflammatory macrophages. Here, we show that D-mannose suppresses LPS-induced macrophage activation by impairing IL-1ß production. In vivo, mannose administration improves survival in a mouse model of LPS-induced endotoxemia as well as decreases progression in a mouse model of DSS-induced colitis. Phosphomannose isomerase controls response of LPS-activated macrophages to D-mannose, which impairs glucose metabolism by raising intracellular mannose-6-phosphate levels. Such alterations result in the suppression of succinate-mediated HIF-1α activation, imposing a consequent reduction of LPS-induced Il1b expression. Disclosing an unrecognized metabolic hijack of macrophage activation, our study points towards safe D-mannose utilization as an effective intervention against inflammatory conditions.


Assuntos
Interleucina-1beta/metabolismo , Ativação de Macrófagos/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Manose/metabolismo , Manose/farmacologia , Animais , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Colite/metabolismo , Colite/patologia , Regulação da Expressão Gênica , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Inflamação/metabolismo , Interleucina-1beta/genética , Lipopolissacarídeos/efeitos adversos , Manosefosfatos/metabolismo , Redes e Vias Metabólicas/efeitos dos fármacos , Metabolômica , Monócitos/metabolismo
2.
Yakugaku Zasshi ; 140(11): 1343-1350, 2020.
Artigo em Japonês | MEDLINE | ID: mdl-33132270

RESUMO

Disruption of redox balance due to the overproduction of free radicals and reactive oxygen species (ROS) could cause protein denaturation, lipid peroxidation, and DNA mutation. These lead to an induction of gastrointestinal diseases such as gastric ulcers induced by long-term administration of non-steroidal anti-inflammatory drugs (NSAIDs) and ulcerative colitis. Magnetic resonance technique, which is non-invasive and free of radiation exposure, is a promising tool for evaluating redox status in the living body. This study investigated ROS production in rats with gastric ulcers induced by a typical NSAIDs indomethacin using in vivo ESR/spin probe technique. The ESR signal intensity of membrane-permeable nitroxyl probe in the indomethacin group showed enhanced decay compared with the vehicle group, but the enhancement was not observed in the presence of a membrane-permeable ROS scavenger, suggesting the intracellular ROS production. The imaging analysis using Overhauser-enhanced MRI (OMRI) with dual probes labeled with 14N and 15N enabled visualization of ROS production in the glandular stomach of rat with indomethacin-induced gastric ulcers. The intracellular ROS production in the distal and proximal colon in the initiation stage and intra- and extra-cellular ROS production of the advanced stage of colitis induced by dextran sodium sulfate (DSS) using the OMRI/dual-probe technique was observed. Furthermore, nitration of src homology protein tyrosine phosphatase 2 in macrophages might be involved in the activation of Toll-like receptor 4 and NF-κB, inducing infiltration of activated neutrophils into colonic mucosa to produce ROS in DSS-induced colitis mice.


Assuntos
Anti-Inflamatórios não Esteroides/efeitos adversos , Colite/metabolismo , Sulfato de Dextrana/efeitos adversos , Radicais Livres/metabolismo , Indometacina/efeitos adversos , Espécies Reativas de Oxigênio/metabolismo , Úlcera Gástrica/metabolismo , Animais , Espectroscopia de Ressonância de Spin Eletrônica , Ratos
3.
PLoS One ; 15(10): e0233938, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33095803

RESUMO

BACKGROUND: Onion is one of the most commonly used plants in the traditional medicine for the treatment of various diseases. We recently demonstrated the anti-inflammatory properties of onion bulb extract (OBE) in reducing colitis severity in mice when administered at the same time of colitis induction. However, whether onion can reverse established colitis or even prevent its development has not been investigated. HYPOTHESIS: To test 1. whether OBE can reduce colitis severity when given either before (preventative approach) or after (treatment approach) colitis induction and if so, 2. what are the mechanisms by which onion can achieve these effects. METHODS: Colitis was induced by dextran sulfate sodium (DSS) administration using treatment and preventative approaches. The severity of the inflammation was determined by the gross and histological assessments. The colonic level/activity of pro-inflammatory molecules and immune cell markers was assessed by immunofluorescence and western blotting analysis. In vitro neutrophil superoxide release and survival was assessed by chemilumenecense and Annexin-V/7AAD assays respectively. RESULTS: OBE treatment significantly reduced colitis severity in both approaches, the colonic expression/activity profile of pro-inflammatory molecules, inhibited WKYMVm-induced superoxide release, and increased spontaneous apoptosis of neutrophils in vitro. CONCLUSIONS: OBE can be used as an effective option in the prevention and/or the treatment of established colitis.


Assuntos
Anti-Inflamatórios/administração & dosagem , Colite/tratamento farmacológico , Cebolas/química , Extratos Vegetais/administração & dosagem , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Colite/induzido quimicamente , Colite/metabolismo , Ciclo-Oxigenase 2/metabolismo , Sulfato de Dextrana/efeitos adversos , Modelos Animais de Doenças , Regulação da Expressão Gênica/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Fosforilação , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Índice de Gravidade de Doença , Resultado do Tratamento
4.
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
5.
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
6.
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
7.
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
8.
Sci Rep ; 10(1): 10180, 2020 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-32576895

RESUMO

CD47 deficient mice are resistant to dextran sulfate sodium (DSS)-induced experimental colitis. The underlying mechanism, however, remains incompletely understood. In this study, we characterized the role of CD47 in modulating homeostasis of gastrointestinal tract. We found that CD47 expression in both human and mouse intestinal epithelium was upregulated in colitic condition compared to that under normal condition. In line with this, CD47 deficiency protected mice from DSS-induced colitis. Analysis based on both intestinal organoid and cultured cell assays showed that CD47 deficiency accelerated intestinal epithelial cell proliferation and migration. Mechanistically, western blot and functional assays indicated that CD47 deficiency promoting mouse intestinal epithelial cell proliferation and migration follow cell injury is likely through upregulating expression of four Yamanaka transcriptional factors Oct4, Sox2, Klf4 and c-Myc (OSKM in abbreviation). Our studies thus reveal CD47 as a negative regulator in intestinal epithelial cell renewal during colitis through downregulating OSKM transcriptional factors.


Assuntos
Antígeno CD47/metabolismo , Autorrenovação Celular/fisiologia , Colite/metabolismo , Células Epiteliais/metabolismo , Mucosa Intestinal/metabolismo , Intestinos/fisiologia , Animais , Apoptose/fisiologia , Linhagem Celular Tumoral , Proliferação de Células/fisiologia , Células Cultivadas , Colite/induzido quimicamente , Sulfato de Dextrana/farmacologia , Modelos Animais de Doenças , Células Epiteliais/efeitos dos fármacos , Células HT29 , Homeostase/fisiologia , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Transdução de Sinais/fisiologia , Regulação para Cima/fisiologia
9.
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
10.
J Nutr ; 150(7): 1966-1976, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32386234

RESUMO

BACKGROUND: L-tryptophan (Trp) has been reported to regulate gut immune responses during inflammation. However, the underlying mechanisms are largely unknown. OBJECTIVE: We investigated the role of Trp supplementation on the serotonin receptor (HTR)-mediated immune response in the colon of mice with dextran sodium sulfate (DSS)-induced colitis. METHODS: In Experiment 1, male C57BL/6 mice were randomly assigned to 1 of 4 groups: Control (Con) or L-Trp supplementation [0.1 mg/(g body weight·d) in drinking water] (Trp) with (+DSS) or without 2% DSS in drinking water from days 8 to 14 of the 17-d study. In Experiments 2 and 3, Trp + DSS (Expt. 2) or DSS (Expt. 3) mice were treated as described above and subcutaneously administered with HTR1A or HTR4 antagonists (or their combination) or an HTR2 agonist from days 8 to 14 of the 15-d study. Changes in immune cell phenotypes, inflammatory mediators, and related cell signaling molecules were assessed by flow cytometry, real-time PCR, or Western blot. The mRNA abundances of Trp hydroxylase (Tph1), serotonin reuptake transporter (Slc6a4), and Htr in the colon were also assessed. RESULTS: Trp supplementation before DSS treatment upregulated the expression of colonic Slc6a4 (0.49 compared with 0.30), Htr1a (1.14 compared with 0.65), and Htr4 (1.08 compared with 0.70), downregulated the expression of Htr2a (1.54 compared with 1.89), and decreased the colonic serotonin concentration (11.5 compared with 14.8 nmol/g tissue) (P < 0.01). Trp regulated the DSS-induced immune response partly through attenuating the activation of toll-like receptor 4 (TLR4)-STAT3 signaling and nucleus p-65. Either an HTR2 agonist or HTR1A and HTR4 antagonists reversed the effects of Trp. CONCLUSIONS: In mice treated with DSS, Trp supplementation before DSS administration improved colonic immune responses partly by reducing colonic serotonin and subsequent interactions with HTR1A and HTR4, which are known to be present on neutrophils and macrophages.


Assuntos
Colite/metabolismo , Colo/metabolismo , Sulfato de Dextrana/toxicidade , Suplementos Nutricionais , Homeostase/efeitos dos fármacos , Antagonistas da Serotonina/farmacologia , Serotonina/metabolismo , Triptofano/farmacologia , Animais , Colite/induzido quimicamente , Dieta , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Piperazinas/farmacologia , Distribuição Aleatória , Antagonistas da Serotonina/administração & dosagem , Triptofano/administração & dosagem
12.
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
13.
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
14.
Biochem Pharmacol ; 177: 113987, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32330496

RESUMO

The cysteinyl leukotrienes (CysLTs), i.e. LTC4, LTD4 and LTE4, are a family of proinflammatory agents synthesized from the arachidonic acid. In target cells, these lipid mediators bind to the cysteinyl leukotriene receptors (CysLTR), a family of seven transmembrane G-protein coupled receptors. The CysLT1R is a validated target for treatment of pulmonary diseases and several selective antagonists for this receptor, including montelukast, zafirlukast and pranlukast, have shown effective in the management of asthma. Nevertheless, others CysLT1R antagonists, such as the alpha-pentyl-3-[2-quinolinylmethoxy] benzyl alcohol (REV5901), have been extensively characterized without reaching sufficient priority for clinical development. Since drug reposition is an efficient approach for maximizing investment in drug discovery, we have investigated whether CysLT1R antagonists might exert off-target effects. In the report we demonstrate that REV5901 interacts with GPBAR1, a well characterized cell membrane receptor for secondary bile acids. REV5901 transactivates GPBAR1 in GPBAR1-transfected cells with an EC50 of 2.5 µM and accommodates the GPBAR1 binding site as shown by in silico analysis. Exposure of macrophages to REV5901 abrogates the inflammatory response elicited by bacterial endotoxin in a GPBAR1-dependent manner. In vivo, in contrast to montelukast, REV5901 attenuates inflammation and immune dysfunction in rodent models of colitis. The beneficial effects exerted by REV5901 in these models were abrogated by GPBAR1 gene ablation, confirming that REV5901, a shelved CysLT1R antagonist, is a GPBAR1 ligand. These data ground the basis for the development of novel hybrid ligands designed for simultaneous modulation of CysTL1R and GPBAR1.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Colite/tratamento farmacológico , Antagonistas de Leucotrienos/farmacologia , Quinolinas/farmacologia , Receptores Acoplados a Proteínas-G/metabolismo , Receptores de Leucotrienos/metabolismo , Acetatos/farmacologia , Animais , Ácidos e Sais Biliares/farmacologia , Colite/genética , Colite/metabolismo , Colite/patologia , Modelos Animais de Doenças , Expressão Gênica , Genes Reporter , Células HEK293 , Células Hep G2 , Humanos , Leucotrieno C4/metabolismo , Leucotrieno D4/metabolismo , Leucotrieno E4/metabolismo , Luciferases/genética , Luciferases/metabolismo , Camundongos , Camundongos Knockout , Simulação de Acoplamento Molecular , Células RAW 264.7 , Receptores Acoplados a Proteínas-G/antagonistas & inibidores , Receptores Acoplados a Proteínas-G/química , Receptores Acoplados a Proteínas-G/genética , Receptores de Leucotrienos/química , Receptores de Leucotrienos/genética , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo
15.
Sci Rep ; 10(1): 4883, 2020 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-32184453

RESUMO

Loss-of-function mutations in the solute carrier organic anion transporter family, member 2a1 gene (SLCO2A1), which encodes a prostaglandin (PG) transporter, have been identified as causes of chronic nonspecific multiple ulcers in the small intestine; however, the underlying mechanisms have not been revealed. We, therefore, evaluated the effects of systemic knockout of Slco2a1 (Slco2a1-/-) and conditional knockout in intestinal epithelial cells (Slco2a1ΔIEC) and macrophages (Slco2a1ΔMP) in mice with dextran sodium sulphate (DSS)-induced acute colitis. Slco2a-/- mice were more susceptible to DSS-induced colitis than wild-type (WT) mice, but did not spontaneously develop enteritis or colitis. The nucleotide-binding domain, leucine-rich repeats containing family, pyrin domain-containing-3 (NLRP3) inflammasome was more strongly upregulated in colon tissues of Slco2a-/- mice administered DSS and in macrophages isolated from Slco2a1-/- mice than in the WT counterparts. Slco2a1ΔMP, but not Slco2a1ΔIEC mice, were more susceptible to DSS-induced colitis than WT mice, partly phenocopying Slco2a-/- mice. Concentrations of PGE2 in colon tissues and macrophages from Slco2a1-/- mice were significantly higher than those of WT mice. Blockade of inflammasome activation suppressed the exacerbation of colitis. These results indicated that Slco2a1-deficiency increases the PGE2 concentration, resulting in NLRP3 inflammasome activation in macrophages, thus exacerbating intestinal inflammation.


Assuntos
Colite/induzido quimicamente , Colite/metabolismo , Colite/patologia , Transportadores de Ânions Orgânicos/deficiência , Transportadores de Ânions Orgânicos/metabolismo , Animais , Western Blotting , Células Cultivadas , Colite/genética , Sulfato de Dextrana/toxicidade , Enterocolite/induzido quimicamente , Enterocolite/genética , Enterocolite/metabolismo , Enterocolite/patologia , Ensaio de Imunoadsorção Enzimática , Inflamassomos/imunologia , Inflamassomos/metabolismo , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Modelos Teóricos , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Transportadores de Ânions Orgânicos/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa
16.
Immunohorizons ; 4(3): 129-139, 2020 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-32156688

RESUMO

TNFR-associated factor 5 (TRAF5) is a cytosolic adaptor protein and functions as an inflammatory regulator. However, the in vivo function of TRAF5 remains unclear, and how TRAF5 controls inflammatory responses in the intestine is not well understood. In this study, we found that intestinal epithelial cells from Traf5-/- mice expressed a significantly lower level of NF-κB-regulated proinflammatory genes, such as Tnf, Il6, and Cxcl1, as early as day 3 after dextran sulfate sodium (DSS) exposure when compared with wild-type mice. The intestinal barrier integrity of DSS-treated Traf5-/- mice remained intact at this early time point, and Traf5-/- mice showed decreased body weight loss and longer colon length at later time points. Surprisingly, the protein level of TRAF2, but not TRAF3, was reduced in colon tissues of Traf5-/- mice after DSS, indicating the requirement of TRAF5 for TRAF2 protein stability in the inflamed colon. Experiments with bone marrow chimeras confirmed that TRAF5 deficiency in nonhematopoietic cells caused the attenuated colitis. Our in vitro experiments demonstrated that proinflammatory cytokines significantly promoted the degradation of TRAF2 protein in Traf5-/- nonhematopoietic cells in a proteasome-dependent manner. Collectively, our data suggest a novel regulatory function of TRAF5 in supporting the proinflammatory function of TRAF2 in nonhematopoietic cells, which may be important for acute inflammatory responses in the intestine.


Assuntos
Colite/induzido quimicamente , Colite/metabolismo , Sulfato de Dextrana/farmacologia , Células Epiteliais/metabolismo , Fibroblastos/metabolismo , Fator 2 Associado a Receptor de TNF/metabolismo , Fator 5 Associado a Receptor de TNF/metabolismo , Animais , Células Cultivadas , Colo/metabolismo , Citocinas/metabolismo , Modelos Animais de Doenças , Inflamação/genética , Inflamação/metabolismo , Mucosa Intestinal/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fator 5 Associado a Receptor de TNF/genética , Transfecção
17.
Pathog Dis ; 78(2)2020 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-32166323

RESUMO

Intestinal mucosal barriers help the body resist many intestinal inflammatory diseases, such as inflammatory bowel disease (IBD). In this study, we identified a novel bacterium promoting the repair of intestinal mucosa and investigated the potential mechanisms underlying its activity. Culture supernatant of Bacillus subtilis RZ001 upregulated the expression of mucin 2 (MUC2) and tight junction (TJ) proteins in HT-29 cells in vitro. Oral administration of B. subtilis RZ001 may have significantly reduced symptoms such as the dextran sulfate sodium (DSS)-induced decrease in body weight, shortening of colon length and overproduction of proinflammatory factors. The number of goblet cells and levels of MUC2 and TJ proteins were significantly increased in adult mice fed with B. subtilis RZ001. B. subtilis RZ001 cells upregulated the levels of MUC2 in the intestinal organoids. Furthermore, culture supernatant of B. subtilis RZ001 could suppress the Notch signalling pathway and activate the expression of atonal homolog 1 (Atoh1). The transcription factor Atoh1 is required for intestinal secretory cell differentiation and activates transcription of MUC2 via binding to E-boxes on the MUC2 promoter. Taken together, B. subtilis strain RZ001 has the potential for treating IBD. The present study is helpful to elucidate the mechanisms of B. subtilis action.


Assuntos
Bacillus subtilis/fisiologia , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Colite/etiologia , Colite/metabolismo , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Receptores Notch/metabolismo , Transdução de Sinais , Animais , Ácidos e Sais Biliares/metabolismo , Biomarcadores , Biópsia , Linhagem Celular Tumoral , Sobrevivência Celular , Colite/patologia , Sulfato de Dextrana/efeitos adversos , Modelos Animais de Doenças , Regulação da Expressão Gênica , Humanos , Masculino , Camundongos , Mucina-2/genética , Mucina-2/metabolismo , Proteínas de Junções Íntimas
18.
Nat Commun ; 11(1): 900, 2020 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-32060280

RESUMO

Copper levels are known to be elevated in inflamed and malignant tissues. But the mechanism underlying this selective enrichment has been elusive. In this study, we report a axis by which inflammatory cytokines, such as IL-17, drive cellular copper uptake via the induction of a metalloreductase, STEAP4. IL-17-induced elevated intracellular copper level leads to the activation of an E3-ligase, XIAP, which potentiates IL-17-induced NFκB activation and suppresses the caspase 3 activity. Importantly, this IL-17-induced STEAP4-dependent cellular copper uptake is critical for colon tumor formation in a murine model of colitis-associated tumorigenesis and STEAP4 expression correlates with IL-17 level and XIAP activation in human colon cancer. In summary, this study reveals a IL-17-STEAP4-XIAP axis through which the inflammatory response induces copper uptake, promoting colon tumorigenesis.


Assuntos
Colo/imunologia , Neoplasias do Colo/imunologia , Cobre/metabolismo , Proteínas Inibidoras de Apoptose/imunologia , Interleucina-17/imunologia , Proteínas de Membrana/imunologia , Animais , Carcinogênese , Colite/genética , Colite/imunologia , Colite/metabolismo , Colo/metabolismo , Neoplasias do Colo/genética , Neoplasias do Colo/metabolismo , Cobre/imunologia , Humanos , Proteínas Inibidoras de Apoptose/genética , Interleucina-17/genética , Proteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout
19.
Phytomedicine ; 68: 153179, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32062328

RESUMO

BACKGROUND: Intestinal epithelial barrier dysfunction, which involves myosin light chain kinase (MLCK) activation, contributes to the occurrence and progression of inflammation in inflammatory bowel disease (IBD). Wogonoside helps maintain intestinal homeostasis in mice with dextran sulfate sodium (DSS)-induced colitis, but it is unclear whether it modulates intestinal barrier function. PURPOSE: Here, we demonstrate that wogonoside protects against intestinal barrier dysfunction in colitis via the MLCK/pMLC2 pathway both in vivo and in vitro. METHODS: Caco-2 cell monolayers treated with the proinflammatory cytokine TNF-α showed barrier dysfunction and were assessed in the absence and presence of wogonoside for various physiological, morphological, and biochemical parameters. Colitis was induced by 3% DSS in mice, which were used as an animal model to explore the pharmacodynamics of wogonoside. We detected MLCK/pMLC2 pathway proteins via western blot analysis, assessed the cytokines IL-13 and IFN-γ via ELISA, tested bacterial translocation via fluorescence in situ hybridization (FISH) and a proper sampling of secondary lymphoid organs for bacterial culture. In addition, the docking affinity of wogonoside and MLCK was observed with DS2.5 software. RESULTS: Wogonoside alleviated the disruption of transepithelial electrical resistance (TER) in TNF-α exposured Caco-2 cell; FITC-dextran hyperpermeability; loss of the tight junction (TJ) proteins occludin, ZO-1 and claudin-1 in Caco-2 cell monolayers; and bacterial translocation in colitic mice. Moreover, wogonoside reduced the levels of the proinflammatory cytokines IL-13 and IFN-γ to maintain intestinal immune homeostasis. Transmission electron microscopy (TEM) confirmed that wogonoside ameliorated the destruction of intestinal epithelial TJs. Wogonoside not only inhibited the cytoskeletal F-actin rearrangement induced by TNF-α, stabilized the cytoskeletal structure, suppressed MLCK protein expression, and reduced MLC2 phosphorylation. In addition, the results of molecular docking analysis showed that wogonoside had a high affinity for MLCK and formed hydrogen bonds with the amino acid residue LYS261 and π bonds with LYS229. CONCLUSION: Collectively, our study indicates that wogonoside alleviates colitis by protecting against intestinal barrier dysfunction, and the potential mechanism may involve regulation of TJs via the MLCK/pMLC2 signaling pathway. Meanwhile, our study also explains the success of S. baicalensis in the treatment of ulcerative colitis (UC).


Assuntos
Miosinas Cardíacas/metabolismo , Colite/tratamento farmacológico , Flavanonas/farmacologia , Glucosídeos/farmacologia , Cadeias Leves de Miosina/metabolismo , Quinase de Cadeia Leve de Miosina/metabolismo , Animais , Células CACO-2 , Colite/induzido quimicamente , Colite/metabolismo , Sulfato de Dextrana/toxicidade , Flavanonas/química , Glucosídeos/química , Humanos , Mucosa Intestinal/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Simulação de Acoplamento Molecular , Fosforilação , Proteínas de Junções Íntimas/metabolismo
20.
Mol Med Rep ; 21(3): 1181-1191, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31922249

RESUMO

Dysbiosis of the enteric microbiota causes gastrointestinal diseases, including colitis. The present study investigated the beneficial effect of Lactobacillus plantarum 06CC2 in experimental colitis in mice. An experimental colitis model in C57BL6 mice was induced using dextran sulfate sodium. Mice were orally administered 06CC2 (06CC2 group) or PBS only (control group) by gavage. The disease activity index (DAI), histological grading, and colon tissue and colonic lamina propria mononuclear cells (LPMCs) were examined macroscopically and histopathologically, and the expression levels of inflammation­associated cytokines (IL­6, IL­12, TNF­α and IL­10) in these samples were determined. Compared with the control group, the 06CC2 group exhibited a significantly lower DAI (1.5±0.8 vs. 0.2±0.3, respectively; P<0.05) and pathology score (6.3±1.5 vs. 3.8±1.3, respectively; P<0.05). IL­10 expression in colonic LPMCs was higher in the 06CC2 group than in the control group, although there was no significant difference in IFN­Î³, IL­6 or IL­12 expression in colonic LPMCs between the two groups. In addition, 06CC2 stimulated the production of IL­10 from CD11b­positive cells and CD11c­positive cells in the colon. The 06CC2 strain induced IL­10 production in the colon and attenuated colon inflammation.


Assuntos
Colite/prevenção & controle , Lactobacillus plantarum , Administração Oral , Animais , Colite/metabolismo , Colite/microbiologia , Colite/patologia , Colo/metabolismo , Colo/microbiologia , Colo/patologia , Citocinas/metabolismo , Modelos Animais de Doenças , Inflamação/metabolismo , Inflamação/patologia , Inflamação/prevenção & controle , Leucócitos Mononucleares/metabolismo , Leucócitos Mononucleares/patologia , Camundongos , Membrana Mucosa/metabolismo , Membrana Mucosa/microbiologia , Membrana Mucosa/patologia
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