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Interferon-gamma (IFNγ) is traditionally recognized for its pro-inflammatory role during intestinal inflammation. Here, we demonstrate that IFNγ also functions as a pro-repair molecule by increasing TNFα receptor 2 (TNFR2 protein/TNFRSF1B gene) expression on intestinal epithelial cells (IEC) following injury in vitro and in vivo. In silico analyses identified binding sites for the IFNγ signaling transcription factor STAT1 in the promoter region of TNFRSF1B. Scratch-wounded IEC exposed to IFNγ exhibited a STAT1-dependent increase in TNFR2 expression. In situ hybridization revealed elevated Tnfrsf1b mRNA levels in biopsy-induced colonic mucosal wounds, while intraperitoneal administration of IFNγ neutralizing antibodies following mucosal injury resulted in impaired IEC Tnfrsf1b mRNA and inhibited colonic mucosal repair. These findings challenge conventional notions that "pro-inflammatory" mediators solely exacerbate damage by highlighting latent pro-repair functions. Moreover, these results emphasize the critical importance of timing and amount in the synthesis and release of IFNγ and TNFα during the inflammatory process, as they are pivotal in restoring tissue homeostasis.
Assuntos
Colo , Interferon gama , Mucosa Intestinal , Receptores Tipo II do Fator de Necrose Tumoral , Fator de Transcrição STAT1 , Transdução de Sinais , Interferon gama/metabolismo , Receptores Tipo II do Fator de Necrose Tumoral/metabolismo , Receptores Tipo II do Fator de Necrose Tumoral/genética , Animais , Humanos , Colo/metabolismo , Colo/patologia , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Fator de Transcrição STAT1/metabolismo , Camundongos , Cicatrização/fisiologia , Camundongos Endogâmicos C57BL , Masculino , Células Epiteliais/metabolismo , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Thrombospondin-1 (TSP1) is a matricellular protein associated with the regulation of cell migration through direct binding interactions with integrin proteins and by associating with other receptors known to regulate integrin function, including CD47 and CD36. We previously demonstrated that deletion of an epithelial TSP1 receptor CD47 attenuates epithelial wound repair following intestinal mucosal injury. However, the mechanisms by which TSP1 contributes to intestinal mucosal repair remains poorly understood. Our results show upregulated TSP1 expression in colonic mucosal wounds and impaired intestinal mucosal wound healing in vivo upon intestinal epithelial specific loss of TSP1 (VillinCre/+Thbs1f/f or Thbs1ΔIEC). We report that exposure to exogenous TSP1 enhanced migration of IECs in a CD47- and TGFß1-dependent manner, and that deficiency of TSP1 in primary murine colonic epithelial cells resulted in impaired wound healing. Mechanistically, TSP1 modulated epithelial actin cytoskeletal dynamics by suppression of RhoA activity, activation of Rac1, and changes in F-actin bundling. Overall, TSP1 was found to regulate intestinal mucosal wound healing via CD47 and TGFß1, coordinate integrin-containing cell-matrix adhesion dynamics and remodel the actin cytoskeleton in migrating epithelial cells to enhance cell motility and promote wound repair.
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Food allergy is a prevalent, potentially deadly disease caused by inadvertent sensitization to benign food antigens. Pathogenic Th2 cells are a major driver for disease, and allergen-specific immunotherapies (AIT) aim to increase the allergen threshold required to elicit severe allergic symptoms. However, the majority of AIT approaches require lengthy treatments and convey transient disease suppression, likely due to insufficient targeting of pathogenic Th2 responses. Here, the ability of allergen-encapsulating nanoparticles to directly suppress pathogenic Th2 responses and reactivity is investigated in a mouse model of food allergy. NPs associate with pro-tolerogenic antigen presenting cells, provoking accumulation of antigen-specific, functionally suppressive regulatory T cells in the small intestine lamina propria. Two intravenous doses of allergen encapsulated in poly(lactide-co-glycolide) nanoparticles (NPs) significantly reduces oral food challenge (OFC)-induced anaphylaxis. Importantly, NP treatment alters the fates of pathogenic allergen-specific Th2 cells, reprogramming these cells toward CD25+FoxP3+ regulatory and CD73+FR4+ anergic phenotypes. NP-mediated reductions in the frequency of effector cells in the gut and mast cell degranulation following OFC are also demonstrated. These studies reveal mechanisms by which an allergen-encapsulating NP therapy and, more broadly, allergen-specific immunotherapies, can rapidly attenuate allergic responses by targeting pathogenic Th2 cells.
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BACKGROUND: Tissue repair and regeneration in the gastrointestinal system are crucial for maintaining homeostasis, with the process relying on intricate cellular interactions and affected by micro- and macro-nutrients. Iron, essential for various biological functions, plays a dual role in tissue healing by potentially causing oxidative damage and participating in anti-inflammatory mechanisms, underscoring its complex relationship with inflammation and tissue repair. OBJECTIVE: The study aimed to elucidate the role of low dietary iron in gastrointestinal tissue repair. METHODS: We utilized quantitative iron measurements to assess iron levels in inflamed regions of patients with ulcerative colitis and Crohn's disease. In addition, 3 mouse models of gastrointestinal injury/repair (dextran sulfate sodium-induced colitis, radiation injury, and wound biopsy) were used to assess the effects of low dietary iron on tissue repair. RESULTS: We found that levels of iron in inflamed regions of both patients with ulcerative colitis and Crohn's disease are elevated. Similarly, during gastrointestinal repair, iron levels were found to be heightened, specifically in intestinal epithelial cells across the 3 injury/repair models. Mice on a low-iron diet showed compromised tissue repair with reduced proliferation. In standard diet, epithelial cells and the stem cell compartment maintain adequate iron stores. However, during a period of iron deficiency, epithelial cells exhaust their iron reserves, whereas the stem cell compartments maintain their iron pools. During injury, when the stem compartment is disrupted, low iron levels impair proliferation and compromise repair mechanisms. CONCLUSIONS: Low dietary iron impairs intestinal repair through compromising the ability of epithelial cells to aid in intestinal proliferation.
Assuntos
Colite Ulcerativa , Colite , Doença de Crohn , Humanos , Camundongos , Animais , Doença de Crohn/patologia , Ferro da Dieta/efeitos adversos , Colite/induzido quimicamente , Cicatrização , Modelos Animais de Doenças , Ferro/farmacologia , Mucosa Intestinal , Sulfato de Dextrana/farmacologia , Camundongos Endogâmicos C57BLRESUMO
Knowledge about the 3-dimensional structure, orientation and interaction of chemical compounds is important in many areas of science and technology. X-ray crystallography is one of the experimental techniques capable of providing a large amount of structural information for a given compound, and it is widely used for characterisation of organic and metal-organic molecules. The method provides precise 3D coordinates of atoms inside crystals, however, it does not directly deliver information about certain chemical characteristics such as bond orders, delocalization, charges, lone electron pairs or lone electrons. These aspects of a molecular model have to be derived from crystallographic data using refined information about interatomic distances and atom types as well as employing general chemical knowledge. This publication describes a curated automatic pipeline for the derivation of chemical attributes of molecules from crystallographic models. The method is applied to build a catalogue of chemical entities in an open-access crystallographic database, the Crystallography Open Database (COD). The catalogue of such chemical entities is provided openly as a derived database. The content of this catalogue and the problems arising in the fully automated pipeline are discussed, along with the possibilities to introduce manual data curation into the process.
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Spatial transcriptomics (ST) technologies have advanced to enable transcriptome-wide gene expression analysis at submicron resolution over large areas. Analysis of high-resolution ST data relies heavily on image-based cell segmentation or gridding, which often fails in complex tissues due to diversity and irregularity of cell size and shape. Existing segmentation-free analysis methods scale only to small regions and a small number of genes, limiting their utility in high-throughput studies. Here we present FICTURE, a segmentation-free spatial factorization method that can handle transcriptome-wide data labeled with billions of submicron resolution spatial coordinates. FICTURE is orders of magnitude more efficient than existing methods and it is compatible with both sequencing- and imaging-based ST data. FICTURE reveals the microscopic ST architecture for challenging tissues, such as vascular, fibrotic, muscular, and lipid-laden areas in real data where previous methods failed. FICTURE's cross-platform generality, scalability, and precision make it a powerful tool for exploring high-resolution ST.
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Published reports of chemical compounds often contain multiple machine-readable descriptions which may supplement each other in order to yield coherent and complete chemical representations. This publication presents a method to cross-check such descriptions using a canonical representation and isomorphism of molecular graphs. If immediate agreement between compound descriptions is not found, the algorithm derives the minimal set of simplifications required for both descriptions to arrive to a matching form (if any). The proposed algorithm is used to cross-check chemical descriptions from the Crystallography Open Database to identify coherently described entries as well as those requiring further curation.
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Resolution of inflammation and mucosal wound healing are crucial processes required to re-establish homeostasis following injury of mucosal tissues. Maresin-2 (MaR2), a lipid specialized pro-resolving mediator derived from omega-3 polyunsaturated fatty acid, has been reported to promote resolution of inflammation. However, a potential role for MaR2 in regulating mucosal repair remains undefined. Using lipidomic analyses, we demonstrate biosynthesis of MaR2 in healing intestinal mucosal wounds in vivo. Importantly, administration of exogenous MaR2 promoted mucosal repair following dextran sulfate sodium-induced colitis or biopsy-induced colonic mucosal injury. Functional analyses revealed that MaR2 promotes mucosal wound repair by driving intestinal epithelial migration through activation of focal cell-matrix adhesion signaling in primary human intestinal epithelial cells. Because of its labile nature, MaR2 is easily degradable and requires ultracold storage to maintain functionality. Thus, we created thermostable polylactic acid MaR2 nanoparticles that retain biological activity following extended storage at 4 °C or above. Taken together, these results establish MaR2 as a potent pro-repair lipid mediator with broad therapeutic potential for use in promoting mucosal repair in inflammatory diseases.
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Colite , Nanopartículas , Humanos , Colite/induzido quimicamente , Colite/tratamento farmacológico , Intestinos , Mucosa Intestinal/fisiologia , Inflamação , Sulfato de Dextrana/efeitos adversosRESUMO
BACKGROUND: Incidences of inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, are escalating worldwide and can be considered a global public health problem. Given that the gold standard approach to IBD therapeutics focuses on reducing the severity of symptoms, there is an urgent unmet need to develop alternative therapies that halt not only inflammatory processes but also promote mucosal repair. Previous studies have identified increased stem cell factor (SCF) expression in inflamed intestinal mucosal tissues. However, the role that SCF plays in mediating intestinal inflammation and repair has not been explored. METHODS: Changes in the expression of SCF were evaluated in the colonic tissue of healthy mice and during dextran sodium sulfate (DSS)-induced colitis. Furthermore, mucosal wound healing and colitis severity were analyzed in mice subjected to either mechanical biopsy or DSS treatment, respectively, following intestinal epithelial cell-specific deletion of SCF or anti-SCF antibody administration. RESULTS: We report robust expression of SCF by intestinal epithelial cells during intestinal homeostasis with a switch to immune cell-produced SCF during colitis. Data from mice with intestinal epithelial cell-specific deletion of SCF highlight the importance of immune cell-produced SCF in driving the pathogenesis of colitis. Importantly, antibody-mediated neutralization of total SCF or the specific SCF248 isoform decreased immune cell infiltration and enhanced mucosal wound repair following biopsy-induced colonic injury or DSS-induced colitis. CONCLUSIONS: These data demonstrate that SCF functions as a pro-inflammatory mediator in mucosal tissues and that specific neutralization of SCF248 could be a viable therapeutic option to reduce intestinal inflammation and promote mucosal wound repair in individuals with IBD.
Our investigation demonstrates that blocking cleavable SCF248 isoform by administration of specific stem cell factor antibodies enhances healing of the intestinal mucosa and restores critical barrier function, suggesting an alternative therapeutic option to treat individuals with active IBD.
Assuntos
Colite Ulcerativa , Colite , Doenças Inflamatórias Intestinais , Animais , Camundongos , Colite/tratamento farmacológico , Colite/patologia , Colite Ulcerativa/tratamento farmacológico , Colite Ulcerativa/patologia , Sulfato de Dextrana , Modelos Animais de Doenças , Inflamação/tratamento farmacológico , Inflamação/patologia , Doenças Inflamatórias Intestinais/tratamento farmacológico , Doenças Inflamatórias Intestinais/patologia , Mucosa Intestinal/patologia , Fator de Células-Tronco/antagonistas & inibidores , Fator de Células-Tronco/metabolismoRESUMO
Acute and chronic intestinal inflammation is associated with epithelial damage, resulting in mucosal wounds in the forms of erosions and ulcers in the intestinal tract. Intestinal epithelial cells (IECs) and immune cells in the wound milieu secrete cytokines and lipid mediators to influence repair. Leukotriene B4 (LTB4), a lipid chemokine, binds to its receptor BLT1 and promotes migration of immune cells to sites of active inflammation; however, a role for intestinal epithelial BLT1 during mucosal wound repair is not known. Here we report that BLT1 was expressed in IECs both in vitro and in vivo, where it functioned as a receptor not only for LTB4 but also for another ligand, resolvin E1. Intestinal epithelial BLT1 expression was increased when epithelial cells were exposed to an inflammatory microenvironment. Using human and murine primary colonic epithelial cells, we reveal that the LTB4/BLT1 pathway promoted epithelial migration and proliferation leading to accelerated epithelial wound repair. Furthermore, in vivo intestinal wound repair experiments in BLT1-deficient mice and bone marrow chimeras demonstrated an important contribution of epithelial BLT1 during colonic mucosal wound repair. Taken together, our findings show a potentially novel prorepair in IEC mechanism mediated by BLT1 signaling.
Assuntos
Lipídeos , Humanos , Animais , CamundongosRESUMO
Junctional adhesion molecule-A (JAM-A) is expressed in several cell types, including epithelial and endothelial cells, as well as some leukocytes. In intestinal epithelial cells (IEC), JAM-A localizes to cell junctions and plays a role in regulating barrier function. In vitro studies with model cell lines have shown that JAM-A contributes to IEC migration; however, in vivo studies investigating the role of JAM-A in cell migration-dependent processes such as mucosal wound repair have not been performed. In this study, we developed an inducible intestinal epithelial-specific JAM-A-knockdown mouse model (Jam-aERΔIEC). While acute induction of IEC-specific loss of JAM-A did not result in spontaneous colitis, such mice had significantly impaired mucosal healing after chemically induced colitis and after biopsy colonic wounding. In vitro primary cultures of JAM-A-deficient IEC demonstrated impaired migration in wound healing assays. Mechanistic studies revealed that JAM-A stabilizes formation of protein signaling complexes containing Rap1A/Talin/ß1 integrin at focal adhesions of migrating IECs. Loss of JAM-A in primary IEC led to decreased Rap1A activity and protein levels of Talin and ß1 integrin, and it led to a reduction in focal adhesion structures. These findings suggest that epithelial JAM-A plays a critical role in controlling mucosal repair in vivo through dynamic regulation of focal adhesions.
Assuntos
Colite , Molécula A de Adesão Juncional , Animais , Colite/induzido quimicamente , Células Endoteliais/metabolismo , Integrina beta1/metabolismo , Camundongos , TalinaRESUMO
Previous studies have demonstrated that, up to a certain degree, Convolutional Neural Networks (CNNs) can tolerate arithmetic approximations. Nonetheless, perturbations must be applied judiciously, to constrain their impact on accuracy. This is a challenging task, since the implementation of inexact operators is often decided at design time, when the application and its robustness profile are unknown, posing the risk of over-constraining or over-provisioning the hardware. Bridging this gap, we propose a two-phase strategy. Our framework first optimizes the target CNN model, reducing the bitwidth of weights and activations and enhancing error resiliency, so that inexact operations can be performed as frequently as possible. Then, it selectively assigns CNN layers to exact or inexact hardware based on a sensitivity metric. Our results show that, within a 5% accuracy degradation, our methodology, including a highly inexact multiplier design, can reduce the cost of MAC operations in CNN inference up to 83.6% compared to state-of-the-art optimized exact implementations.
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Three copper(II)/mesoxalate-based MOFs with formulas (H3O)[Cu9(Hmesox)6(H2O)6Cl]·8H2O (1), (NH2Me2)0.4(H3O)0.6[Cu9(Hmesox)6(H2O)6Cl]·8H2O (2), and (enH2)0.25(enH)1.5[Cu6(Hmesox)3(mesox)(H2O)6Cl0.5]Cl0.5·5.25H2O (3) were synthesized (H4mesox = mesoxalic acid = 2,2-dihydroxypropanedioic acid, en = ethylenediamine). Essentially, all of the compounds display the same anionic network with a different arrangement of the cations, which have a remarkable effect on the proton conduction of the materials, ranging from 1.16 × 10-4 S cm-1 for 1 to 1.87 × 10-3 S cm-1 for 3 (at 80 °C and 95% RH). These compounds also display antiferromagnetic coupling among the copper(II) ions through both the carboxylate and alkoxido bridges. The values of the principal magnetic coupling constants were calculated by density functional theory (DFT), leading to congruent values that confirm the predominant antiferromagnetic nature of the interactions.
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BACKGROUND: The World Health Organization catalogues illnesses such as Chagas disease as neglected diseases, due to the low investment in new drugs to fight them. The search for novel and non-side effects anti-parasitic compounds is one of the urgent needs of the Third World. The use of triazolopyrimidines and their metal complexes have demonstrated hopeful results in this field. OBJECTIVE: This work studies the antiparasitic efficacy against Trypanosoma cruzi strains of a series of zinc triazolopyrimidine complexes. METHODS: A series of Zn complexes has been synthesized by the reaction between the triazolopyrimidine derivatives 7-amino-1,2,4-triazolo[1,5-a]pyrimidine (7atp) and 5,7-dimethyl-1,2,4-triazolo[1,5- a]pyrimidine (dmtp) with Zn(SO4) · 7H2O, ZnCl2, and Zn(NO3)2 · 6H2O salts. The complexes have been analyzed by spectroscopic and thermal assays and X-ray diffraction methods have been used to dilucidate the crystalline structure of one of them. The antiparasitic efficacy was tested in vitro against Trypanosoma cruzi to compare the trypanocidal effect of different ligands and counteranions to fight Chagas disease. RESULTS: The efficacy of these compounds against Trypanosoma cruzi has also been tested to compare the influence of different ligands and counteranions on the trypanocidal effect against Chagas disease. CONCLUSION: Antiproliferative tests corroborate the synergistic trypanocidal effect of the triazolopyrimidine coordination complexes.
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Doença de Chagas , Complexos de Coordenação , Tripanossomicidas , Trypanosoma cruzi , Doença de Chagas/tratamento farmacológico , Complexos de Coordenação/química , Complexos de Coordenação/farmacologia , Humanos , Pirimidinas/química , Tripanossomicidas/farmacologia , Zinco/química , Zinco/farmacologiaRESUMO
The intestinal epithelium is comprised of a single layer of cells that act as a barrier between the gut lumen and the interior of the body. Disruption in the continuity of this barrier can result in inflammatory disorders such as inflammatory bowel disease. One of the limitations in the study of intestinal epithelial biology has been the lack of primary cell culture models, which has obliged researchers to use model cell lines derived from carcinomas. The advent of three dimensional (3D) enteroids has given epithelial biologists a powerful tool to generate primary cell cultures, nevertheless, these structures are embedded in extracellular matrix and lack the maturity characteristic of differentiated intestinal epithelial cells. Several techniques to generate intestinal epithelial monolayers have been published, but most are derived from established 3D enteroids making the process laborious and expensive. Here we describe a protocol to generate primary epithelial colon monolayers directly from murine intestinal crypts. We also detail experimental approaches that can be used with this model such as the generation of confluent cultures on permeable filters, confluent monolayer for scratch wound healing studies and sparse and confluent monolayers for immunofluorescence analysis.
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Diferenciação Celular , Colo/citologia , Células Epiteliais/citologia , Mucosa Intestinal/citologia , Cultura Primária de Células/métodos , Animais , Técnicas de Cultura de Células/métodos , Células Cultivadas , Camundongos , Camundongos Endogâmicos C57BLRESUMO
Dysregulated neutrophil (PMN) transmigration across epithelial surfaces (TEpM) significantly contributes to chronic inflammatory diseases, yet mechanisms defining this process remain poorly understood. In the intestine, uncontrolled PMN TEpM is a hallmark of disease flares in ulcerative colitis. Previous in vitro studies directed at identifying molecular determinants that mediate TEpM have shown that plasma membrane proteins including CD47 and CD11b/CD18 play key roles in regulating PMN TEpM across monolayers of intestinal epithelial cells. Here, we show that CD47 modulates PMN TEpM in vivo using an ileal loop assay. Importantly, using novel tissue-specific CD47 knockout mice and in vitro approaches, we report that PMN-expressed, but not epithelial-expressed CD47 plays a major role in regulating PMN TEpM. We show that CD47 associates with CD11b/CD18 in the plasma membrane of PMN, and that loss of CD47 results in impaired CD11b/CD18 activation. In addition, in vitro and in vivo studies using function blocking antibodies support a role of CD47 in regulating CD11b-dependent PMN TEpM and chemotaxis. Taken together, these findings provide new insights for developing approaches to target dysregulated PMN infiltration in the intestine. Moreover, tissue-specific CD47 knockout mice constitute an important new tool to study contributions of cells expressing CD47 to inflammation in vivo.
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Antígeno CD47/metabolismo , Inflamação/imunologia , Intestinos/imunologia , Neutrófilos/imunologia , Animais , Antígeno CD11b/metabolismo , Antígenos CD18/metabolismo , Antígeno CD47/genética , Células Cultivadas , Quimiotaxia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Ativação de Neutrófilo , Especificidade de Órgãos , Migração Transendotelial e TransepitelialRESUMO
G protein-coupled receptors (GPCRs) are crucial for establishing the resolution phase following an intestinal inflammatory episode. Because current treatments for intestinal inflammation have a high percentage of failure and lead to immunosuppression, repair GPCRs have promising therapeutic potential because they trigger resolution pathways without compromising the immune response.
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Mucosa Intestinal/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Cicatrização/fisiologia , Animais , Enterocolite/etiologia , Enterocolite/metabolismo , Enterocolite/patologia , Enterocolite/terapia , Humanos , Mucosa Intestinal/imunologia , Mucosa Intestinal/patologia , Regeneração , Medicina Regenerativa , Transdução de SinaisRESUMO
We report on the formation of a triazolopyrimidine derivative ligand, 7-amino-5-methyl-1,2,4-triazolo[1,5-a]pyrimidine (7-amtp), and a new family of coordination compounds based on this ligand and zinc as metal ion, synthesized by conventional routes. These materials possess different mononuclear structures, namely [ZnCl2(7-amtp)2] (1), [Zn(7-amtp)2(H2O)4](NO3)2·2(7-amtp)·6H2O (2) and [Zn(7-amtp)2(H2O)4](SO4)·1.5H2O (3) derived from the use of different zinc (II) salts, in such a way that the counterions govern the crystallization to a large extent. These compounds present and show variable luminescent properties based on ligand-centred charge transfers which have been deeply studied by Time Dependent Density Functional Theory (TD-DFT) calculations. When these compounds are transferred to solution, preserving complex entities as corroborated by NMR studies, they present interesting anti-diabetic and anti-parasitic capabilities, with a comparatively higher selectivity index than other previously reported triazolopyrimidine-based materials. The results derived from in vivo experiments conducted in mice also confirm their promising activity as anti-diabetic drug being capable of dropping glucose levels after oral administration. Therefore, these new materials may be considered as excellent candidates to be further investigated in the field of luminescent coordination compounds with biomedical applications.
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Antiparasitários/farmacologia , Complexos de Coordenação/farmacologia , Hipoglicemiantes/farmacologia , Pirimidinas/química , Zinco/química , LigantesRESUMO
Dysregulated healing of injured mucosa is a hallmark of many pathological conditions, including inflammatory bowel disease. Mucosal injury and chronic intestinal inflammation are also associated with alterations in epithelial glycosylation. Previous studies have revealed that inflammation-induced glycan sialyl Lewis A on epithelial CD44v6 acts as a ligand for transmigrating PMNs. Here we report that robust sialylated Lewis glycan expression was induced in colonic mucosa from individuals with ulcerative colitis and Crohn disease as well as in the colonic epithelium of mice with colitis induced by dextran sodium sulfate (DSS). Targeting of sialylated epithelial Lewis glycans with mAb GM35 reduced disease activity and improved mucosal integrity during DSS-induced colitis in mice. Wound healing studies revealed increased epithelial proliferation and migration responses as well as improved mucosal repair after ligation of epithelial sialyl Lewis glycans. Finally, we showed that GM35-mediated increases in epithelial proliferation and migration were mediated through activation of kinases that signal downstream of CD44v6 (Src, FAK, Akt). These findings suggest that sialylated Lewis glycans on CD44v6 represent epithelial targets for improved recovery of intestinal barrier function and restitution of mucosal homeostasis after inflammation or injury.
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Colite/metabolismo , Colo/patologia , Células Epiteliais/metabolismo , Mucosa Intestinal/patologia , Cicatrização/fisiologia , Animais , Movimento Celular/fisiologia , Proliferação de Células/fisiologia , Colite/induzido quimicamente , Colite/tratamento farmacológico , Colo/metabolismo , Modelos Animais de Doenças , Células Epiteliais/patologia , Doenças Inflamatórias Intestinais/tratamento farmacológico , Doenças Inflamatórias Intestinais/metabolismo , Mucosa Intestinal/metabolismo , Camundongos Endogâmicos C57BLRESUMO
Resolution of intestinal inflammation and wound repair are active processes that mediate epithelial healing at mucosal surfaces. Lipid molecules referred to as specialized proresolving mediators (SPMs) play an important role in the restorative response. Resolvin E1 (RvE1), a SPM derived from omega-3 fatty acids, has been reported to dampen intestinal inflammation by promoting anti-inflammatory responses including increased neutrophil spherocytosis and macrophage production of IL-10. Despite these observations, a role for RvE1 in regulating intestinal epithelial cell migration and proliferation during mucosal wound repair has not been explored. Using an endoscopic biopsy-based wound healing model, we report that RvE1 is locally produced in response to intestinal mucosal injury. Exposure of intestinal epithelial cells to RvE1 promoted wound repair by increasing cellular proliferation and migration through activation of signaling pathways including CREB, mTOR, and Src-FAK. Additionally, RvE1-triggered activation of the small GTPase Rac1 led to increased intracellular reactive oxygen species (ROS) production, cell-matrix adhesion, and cellular protrusions at the leading edge of migrating cells. Furthermore, in situ administration of RvE1-encapsulated synthetic targeted polymeric nanoparticles into intestinal wounds promoted mucosal repair. Together, these findings demonstrate that RvE1 functions as a prorepair lipid mediator by increasing intestinal epithelial cell migration and proliferation, and highlight potential therapeutic applications for this SPM to promote mucosal healing in the intestine.