RESUMEN

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 remain poorly understood. Our results show upregulated TSP1 expression in colonic mucosal wounds and impaired intestinal mucosal wound healing in vivo upon intestinal epithelium-specific loss of TSP1 (VillinCre/+ Thbs1fl/fl or Thbs1ΔIEC mice). We report that exposure to exogenous TSP1 enhanced migration of intestinal epithelial cells in a CD47- and TGF-ß1-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 through suppression of RhoA activity, activation of Rho family small GTPase (Rac1), and changes in filamentous-actin bundling. Overall, TSP1 was found to regulate intestinal mucosal wound healing via CD47 and TGF-ß1, coordinate integrin-containing cell-matrix adhesion dynamics, and remodel the actin cytoskeleton in migrating epithelial cells to enhance cell motility and promote wound repair.

Asunto(s)

Antígeno CD47 , Movimiento Celular , Mucosa Intestinal , Trombospondina 1 , Factor de Crecimiento Transformador beta1 , Cicatrización de Heridas , Animales , Trombospondina 1/metabolismo , Trombospondina 1/genética , Cicatrización de Heridas/fisiología , Ratones , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patología , Antígeno CD47/metabolismo , Antígeno CD47/genética , Factor de Crecimiento Transformador beta1/metabolismo , Proteína de Unión al GTP rhoA/metabolismo , Ratones Noqueados , Proteína de Unión al GTP rac1/metabolismo , Células Epiteliales/metabolismo , Humanos , Colon/metabolismo , Colon/patología , Masculino , Neuropéptidos

RESUMEN

Claudin family tight junction proteins form charge- and size-selective paracellular channels that regulate epithelial barrier function. In the gastrointestinal tract, barrier heterogeneity is attributed to differential claudin expression. Here, we show that claudin-23 (CLDN23) is enriched in luminal intestinal epithelial cells where it strengthens the epithelial barrier. Complementary approaches reveal that CLDN23 regulates paracellular ion and macromolecule permeability by associating with CLDN3 and CLDN4 and regulating their distribution in tight junctions. Computational modeling suggests that CLDN23 forms heteromeric and heterotypic complexes with CLDN3 and CLDN4 that have unique pore architecture and overall net charge. These computational simulation analyses further suggest that pore properties are interaction-dependent, since differently organized complexes with the same claudin stoichiometry form pores with unique architecture. Our findings provide insight into tight junction organization and propose a model whereby different claudins combine to form multiple distinct complexes that modify epithelial barrier function by altering tight junction structure.

Asunto(s)

Claudinas , Uniones Estrechas , Uniones Estrechas/metabolismo , Claudinas/genética , Claudinas/química , Simulación por Computador , Células Epiteliales/metabolismo

RESUMEN

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.

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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.

Asunto(s)

Colitis Ulcerosa , Colitis , Enfermedades Inflamatorias del Intestino , Animales , Ratones , Colitis/tratamiento farmacológico , Colitis/patología , Colitis Ulcerosa/tratamiento farmacológico , Colitis Ulcerosa/patología , Sulfato de Dextran , Modelos Animales de Enfermedad , Inflamación/tratamiento farmacológico , Inflamación/patología , Enfermedades Inflamatorias del Intestino/tratamiento farmacológico , Enfermedades Inflamatorias del Intestino/patología , Mucosa Intestinal/patología , Factor de Células Madre/antagonistas & inhibidores , Factor de Células Madre/metabolismo

RESUMEN

Polymorphonuclear neutrophils (PMNs) play a critical role in clearing invading microbes and promoting tissue repair following infection/injury. However, dysregulated PMN trafficking and associated tissue damage is pathognomonic of numerous inflammatory mucosal diseases. The final step in PMN influx into mucosal lined organs (including the lungs, kidneys, skin, and gut) involves transepithelial migration (TEpM). The ß2-integrin CD11b/CD18 plays an important role in mediating PMN intestinal trafficking, with recent studies highlighting that terminal fucose and GlcNAc glycans on CD11b/CD18 can be targeted to reduce TEpM. However, the role of the most abundant terminal glycan, sialic acid (Sia), in regulating PMN epithelial influx and mucosal inflammatory function is not well understood. Here we demonstrate that inhibiting sialidase-mediated removal of α2-3-linked Sia from CD11b/CD18 inhibits PMN migration across intestinal epithelium in vitro and in vivo. Sialylation was also found to regulate critical PMN inflammatory effector functions, including degranulation and superoxide release. Finally, we demonstrate that sialidase inhibition reduces bacterial peptide-mediated CD11b/CD18 activation in PMN and blocks downstream intracellular signaling mediated by spleen tyrosine kinase (Syk) and p38 MAPK. These findings suggest that sialylated glycans on CD11b/CD18 represent potentially novel targets for ameliorating PMN-mediated tissue destruction in inflammatory mucosal diseases.

Asunto(s)

Neutrófilos , Migración Transendotelial y Transepitelial , Mucosa Intestinal , Neuraminidasa , Neutrófilos/fisiología , Polisacáridos , Antígeno CD11b/inmunología , Antígenos CD18/inmunología

RESUMEN

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.

Asunto(s)

Colitis , Nanopartículas , Humanos , Colitis/inducido químicamente , Colitis/tratamiento farmacológico , Intestinos , Mucosa Intestinal/fisiología , Inflamación , Sulfato de Dextran/efectos adversos

RESUMEN

Glycans are essential cellular components that facilitate a range of critical functions important for tissue development and mucosal homeostasis. Furthermore, specific alterations in glycosylation represent important diagnostic hallmarks of cancer that contribute to tumor cell dissociation, invasion, and metastasis. However, much less is known about how glycosylation contributes to the pathobiology of inflammatory mucosal diseases. Here we will review how epithelial and immune cell glycosylation regulates gut homeostasis and how inflammation-driven changes in glycosylation contribute to intestinal pathobiology.

Asunto(s)

Mucosa Intestinal , Polisacáridos , Glicosilación , Homeostasis , Humanos , Inflamación/metabolismo , Polisacáridos/metabolismo

RESUMEN

The precise mechanism by which oral infection contributes to the pathogenesis of extra-oral diseases remains unclear. Here, we report that periodontal inflammation exacerbates gut inflammation in vivo. Periodontitis leads to expansion of oral pathobionts, including Klebsiella and Enterobacter species, in the oral cavity. Amassed oral pathobionts are ingested and translocate to the gut, where they activate the inflammasome in colonic mononuclear phagocytes, triggering inflammation. In parallel, periodontitis results in generation of oral pathobiont-reactive Th17 cells in the oral cavity. Oral pathobiont-reactive Th17 cells are imprinted with gut tropism and migrate to the inflamed gut. When in the gut, Th17 cells of oral origin can be activated by translocated oral pathobionts and cause development of colitis, but they are not activated by gut-resident microbes. Thus, oral inflammation, such as periodontitis, exacerbates gut inflammation by supplying the gut with both colitogenic pathobionts and pathogenic T cells.

Asunto(s)

Colitis/patología , Enterobacter/fisiología , Microbioma Gastrointestinal , Klebsiella/fisiología , Boca/microbiología , Animales , Colitis/microbiología , Colon/microbiología , Colon/patología , Modelos Animales de Enfermedad , Enterobacter/aislamiento & purificación , Femenino , Inflamasomas/metabolismo , Interleucina-10/deficiencia , Interleucina-10/genética , Interleucina-1beta/metabolismo , Klebsiella/aislamiento & purificación , Leucocitos Mononucleares/citología , Leucocitos Mononucleares/inmunología , Leucocitos Mononucleares/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Periodontitis/microbiología , Periodontitis/patología , Células Th17/citología , Células Th17/inmunología , Células Th17/metabolismo

RESUMEN

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.

Asunto(s)

Colitis/metabolismo , Colon/patología , Células Epiteliales/metabolismo , Mucosa Intestinal/patología , Cicatrización de Heridas/fisiología , Animales , Movimiento Celular/fisiología , Proliferación Celular/fisiología , Colitis/inducido químicamente , Colitis/tratamiento farmacológico , Colon/metabolismo , Modelos Animales de Enfermedad , Células Epiteliales/patología , Enfermedades Inflamatorias del Intestino/tratamiento farmacológico , Enfermedades Inflamatorias del Intestino/metabolismo , Mucosa Intestinal/metabolismo , Ratones Endogámicos C57BL

RESUMEN

Gut microbiota and their metabolites are instrumental in regulating intestinal homeostasis. However, early-life microbiota associated influences on intestinal development remain incompletely understood. Here we demonstrate that co-housing of germ-free (GF) mice with specific-pathogen free (SPF) mice at weaning (exGF) results in altered intestinal gene expression. Our results reveal that one highly differentially expressed gene, erythroid differentiation regulator-1 (Erdr1), is induced during development in SPF but not GF or exGF mice and localizes to Lgr5+ stem cells and transit amplifying (TA) cells. Erdr1 functions to induce Wnt signaling in epithelial cells, increase Lgr5+ stem cell expansion, and promote intestinal organoid growth. Additionally, Erdr1 accelerates scratch-wound closure in vitro, increases Lgr5+ intestinal stem cell regeneration following radiation-induced injury in vivo, and enhances recovery from dextran sodium sulfate (DSS)-induced colonic damage. Collectively, our findings indicate that early-life microbiota controls Erdr1-mediated intestinal epithelial proliferation and regeneration in response to mucosal damage.

Asunto(s)

Proteínas de la Membrana/metabolismo , Microbiota , Regeneración , Células Madre/citología , Proteínas Supresoras de Tumor/metabolismo , Animales , Proliferación Celular/genética , Colitis/inducido químicamente , Colitis/microbiología , Colitis/patología , Sulfato de Dextran , Células Epiteliales/metabolismo , Regulación de la Expresión Génica , Vida Libre de Gérmenes , Humanos , Luciferasas/metabolismo , Ratones Endogámicos C57BL , Microbiota/genética , Organoides/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Células Madre/metabolismo , Vía de Señalización Wnt/genética , Cicatrización de Heridas/genética

RESUMEN

Polymorphonuclear neutrophils (PMNs) play a critical role in the innate immune response to invading pathogens. However, dysregulated mucosal trafficking of PMNs and associated epithelial tissue damage is a pathological hallmark of numerous inflammatory conditions including inflammatory bowel disease. The glycoprotein CD11b/CD18 plays a well-described role in regulating PMN transepithelial migration and PMN inflammatory functions. Previous studies have demonstrated that targeting of the N-linked glycan Lewis X on CD11b blocks PMN transepithelial migration (TEpM). Given evidence of glycosylation-dependent regulation of CD11b/CD18 function, we performed MALDI TOF Mass Spectrometry (MS) analyses on CD11b/CD18 purified from human PMNs. Unusual glycan epitopes identified on CD11b/CD18 included high Mannose oligosaccharides recognized by the Galanthus Nivalis lectin and biantennary galactosylated N-glycans recognized by the Phaseolus Vulgaris erythroagglutinin lectin. Importantly, we show that selective targeting of glycans on CD11b with such lectins results in altered intracellular signaling events that inhibit TEpM and differentially affect key PMN inflammatory functions including phagocytosis, superoxide release and apoptosis. Taken together, these data demonstrate that discrete glycan motifs expressed on CD11b/CD18 such as biantennary galactose could represent novel targets for selective manipulation of CD11b function and reduction of PMN-associated tissue damage in chronic inflammatory diseases.

Asunto(s)

Antígeno CD11b/inmunología , Antígenos CD18/inmunología , Epítopos/inmunología , Neutrófilos/inmunología , Antígeno CD11b/química , Antígenos CD18/química , Epítopos/química , Humanos , Lectinas de Unión a Manosa/química , Lectinas de Unión a Manosa/farmacología , Neutrófilos/química , Fagocitosis , Fitohemaglutininas/química , Fitohemaglutininas/farmacología , Lectinas de Plantas/química , Lectinas de Plantas/farmacología , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Superóxidos/química , Superóxidos/inmunología , Migración Transendotelial y Transepitelial

RESUMEN

CD47 is a ubiquitously expressed transmembrane glycoprotein that regulates inflammatory responses and tissue repair. Here, we show that normal mice treated with anti-CD47 antibodies, and Cd47-null mice have impaired intestinal mucosal wound healing. Furthermore, intestinal epithelial cell (IEC)-specific loss of CD47 does not induce spontaneous immune-mediated intestinal barrier disruption but results in defective mucosal repair after biopsy-induced colonic wounding or Dextran Sulfate Sodium (DSS)-induced mucosal damage. In vitro analyses using primary cultures of CD47-deficient murine colonic IEC or human colonoid-derived IEC treated with CD47-blocking antibodies demonstrate impaired epithelial cell migration in wound healing assays. Defective wound repair after CD47 loss is linked to decreased epithelial ß1 integrin and focal adhesion signaling, as well as reduced thrombospondin-1 and TGF-ß1. These results demonstrate a critical role for IEC-expressed CD47 in regulating mucosal repair and raise important considerations for possible alterations in wound healing secondary to therapeutic targeting of CD47.

Asunto(s)

Antígeno CD47/metabolismo , Células Epiteliales/metabolismo , Mucosa Intestinal/metabolismo , Intestinos/fisiopatología , Cicatrización de Heridas/fisiología , Animales , Antígeno CD47/genética , Colitis/inducido químicamente , Colitis/genética , Colitis/metabolismo , Sulfato de Dextran , Modelos Animales de Enfermedad , Humanos , Mucosa Intestinal/patología , Intestinos/patología , Masculino , Ratones Endogámicos C57BL , Ratones Noqueados , Transducción de Señal/genética , Trombospondina 1/metabolismo , Factor de Crecimiento Transformador beta1/metabolismo , Cicatrización de Heridas/genética

RESUMEN

Skin and intestinal epithelial barriers play a pivotal role in protecting underlying tissues from harsh external environments. The protective role of these epithelia is, in part, dependent on a remarkable capacity to restore barrier function and tissue homeostasis after injury. In response to damage, epithelial wounds repair by a series of events that integrate epithelial responses with those of resident and infiltrating immune cells including neutrophils and monocytes/macrophages. Compromise of this complex interplay predisposes to development of chronic nonhealing wounds, contributing to morbidity and mortality of many diseases. Improved understanding of crosstalk between epithelial and immune cells during wound repair is necessary for development of better pro-resolving strategies to treat debilitating complications of disorders ranging from inflammatory bowel disease to diabetes. In this Review we focus on epithelial and innate immune cell interactions that mediate wound healing and restoration of tissue homeostasis in the skin and intestine.

Asunto(s)

Comunicación Celular/inmunología , Células Epiteliales/inmunología , Homeostasis/inmunología , Neutrófilos/inmunología , Cicatrización de Heridas/inmunología , Animales , Diabetes Mellitus/inmunología , Diabetes Mellitus/patología , Células Epiteliales/patología , Humanos , Enfermedades Inflamatorias del Intestino/inmunología , Enfermedades Inflamatorias del Intestino/patología , Neutrófilos/patología , Piel/inmunología , Piel/patología , Heridas y Lesiones/inmunología , Heridas y Lesiones/patología

RESUMEN

Pathobiology of several chronic inflammatory disorders, including ulcerative colitis and Crohn's disease is related to intermittent, spontaneous injury/ulceration of mucosal surfaces. Disease morbidity has been associated with pathologic release of the pro-inflammatory cytokine tumor necrosis factor alpha (TNFα). In this report, we show that TNFα promotes intestinal mucosal repair through upregulation of the GPCR platelet activating factor receptor (PAFR) in the intestinal epithelium. Platelet activating factor (PAF) was increased in healing mucosal wounds and its engagement with epithelial PAFR leads to activation of epidermal growth factor receptor, Src and Rac1 signaling to promote wound closure. Consistent with these findings, delayed colonic mucosal repair was observed after administration of a neutralizing TNFα antibody and in mice lacking PAFR. These findings suggest that in the injured mucosa, the pro-inflammatory milieu containing TNFα and PAF sets the stage for reparative events mediated by PAFR signaling.

Asunto(s)

Epitelio/metabolismo , Membrana Mucosa/metabolismo , Glicoproteínas de Membrana Plaquetaria/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Transducción de Señal , Factor de Necrosis Tumoral alfa/metabolismo , Cicatrización de Heridas , Proteína ADAM10/metabolismo , Animales , Biomarcadores , Epitelio/patología , Humanos , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patología , Ratones , Membrana Mucosa/patología , FN-kappa B/metabolismo , Glicoproteínas de Membrana Plaquetaria/genética , Especies Reactivas de Oxígeno/metabolismo , Receptores Acoplados a Proteínas G/genética , Proteína de Unión al GTP rac1/metabolismo

RESUMEN

Junctional adhesion molecule-A (JAM-A), an epithelial tight junction protein, plays an important role in regulating intestinal permeability through association with a scaffold signaling complex containing ZO-2, Afadin, and the small GTPase Rap2. Under inflammatory conditions, we report that the cytoplasmic tail of JAM-A is tyrosine phosphorylated (p-Y280) in association with loss of barrier function. While barely detectable Y280 phosphorylation was observed in confluent monolayers of human intestinal epithelial cells under basal conditions, exposure to cytokines TNFα, IFNγ, IL-22, or IL-17A, resulted in compromised barrier function in parallel with increased p-Y280. Phosphorylation was Src kinase dependent, and we identified Yes-1 and PTPN13 as a major kinase and phosphatase for p-JAM-A Y280, respectively. Moreover, cytokines IL-22 or IL-17A induced increased activity of Yes-1. Furthermore, the Src kinase inhibitor PP2 rescued cytokine-induced epithelial barrier defects and inhibited phosphorylation of JAM-A Y280 in vitro. Phosphorylation of JAM-A Y280 and increased permeability correlated with reduced JAM-A association with active Rap2. Finally, we observed increased phosphorylation of Y280 in colonic epithelium of individuals with ulcerative colitis and in mice with experimentally induced colitis. These findings support a novel mechanism by which tyrosine phosphorylation of JAM-A Y280 regulates epithelial barrier function during inflammation.

Asunto(s)

Células Epiteliales/metabolismo , Inflamación/patología , Intestinos/patología , Molécula A de Adhesión de Unión/metabolismo , Fosfotirosina/metabolismo , Secuencia de Aminoácidos , Animales , Colitis Ulcerosa/inducido químicamente , Colitis Ulcerosa/metabolismo , Colitis Ulcerosa/patología , Citocinas/farmacología , Sulfato de Dextran , Células HEK293 , Humanos , Intestinos/química , Ratones Endogámicos C57BL , Modelos Biológicos , Fosforilación/efectos de los fármacos , Proteína Tirosina Fosfatasa no Receptora Tipo 13/metabolismo , Proteínas Proto-Oncogénicas c-yes/metabolismo , Uniones Estrechas/efectos de los fármacos , Uniones Estrechas/metabolismo , Proteínas de Unión al GTP rap/metabolismo

RESUMEN

Estradiol-based therapies predispose women to vaginal infections. Moreover, it has long been known that neutrophils are absent from the vaginal lumen during the ovulatory phase (high estradiol). However, the mechanisms that regulate neutrophil influx to the vagina remain unknown. We investigated the neutrophil transepithelial migration (TEM) into the vaginal lumen. We revealed that estradiol reduces the CD44 and CD47 epithelial expression in the vaginal ectocervix and fornix, which retain neutrophils at the apical epithelium through the estradiol receptor-alpha. In contrast, luteal progesterone increases epithelial expression of CD44 and CD47 to promote neutrophil migration into the vaginal lumen and Candida albicans destruction. Distinctive to vaginal mucosa, neutrophil infiltration is contingent to sex hormones to prevent sperm from neutrophil attack; although it may compromise immunity during ovulation. Thus, sex hormones orchestrate tolerance and immunity in the vaginal lumen by regulating neutrophil TEM.

Asunto(s)

Candidiasis Vulvovaginal/inmunología , Receptor alfa de Estrógeno/genética , Infiltración Neutrófila , Neutrófilos/inmunología , Migración Transendotelial y Transepitelial , Vagina/inmunología , Animales , Antígeno CD47/genética , Antígeno CD47/inmunología , Candida albicans , Células Cultivadas , Cuello del Útero/inmunología , Cuello del Útero/microbiología , Estradiol/farmacología , Receptor alfa de Estrógeno/inmunología , Femenino , Hormonas Esteroides Gonadales/farmacología , Receptores de Hialuranos/genética , Receptores de Hialuranos/inmunología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Noqueados , Progesterona/farmacología , Vagina/microbiología

RESUMEN

In response to injury, epithelial cells migrate and proliferate to cover denuded mucosal surfaces and repair the barrier defect. This process is orchestrated by dynamic crosstalk between immune cells and the epithelium; however, the mechanisms involved remain incompletely understood. Here, we report that IL-10 was rapidly induced following intestinal mucosal injury and was required for optimal intestinal mucosal wound closure. Conditional deletion of IL-10 specifically in CD11c-expressing cells in vivo implicated macrophages as a critical innate immune contributor to IL-10-induced wound closure. Consistent with these findings, wound closure in T cell- and B cell-deficient Rag1-/- mice was unimpaired, demonstrating that adaptive immune cells are not absolutely required for this process. Further, following mucosal injury, macrophage-derived IL-10 resulted in epithelial cAMP response element-binding protein (CREB) activation and subsequent synthesis and secretion of the pro-repair WNT1-inducible signaling protein 1 (WISP-1). WISP-1 induced epithelial cell proliferation and wound closure by activating epithelial pro-proliferative pathways. These findings define the involvement of macrophages in regulating an IL-10/CREB/WISP-1 signaling axis, with broad implications in linking innate immune activation to mucosal wound repair.

Asunto(s)

Proteínas CCN de Señalización Intercelular/metabolismo , Interleucina-10/metabolismo , Macrófagos/metabolismo , Proteínas Proto-Oncogénicas/metabolismo , Animales , Antígenos CD11/metabolismo , Proliferación Celular , Colon/patología , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Células Epiteliales/citología , Células Epiteliales/metabolismo , Eliminación de Gen , Regulación de la Expresión Génica , Humanos , Inflamación , Mucosa Intestinal/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Transducción de Señal , Cicatrización de Heridas

RESUMEN

PMN-expressed fucosylated glycans from the Lewis glycan family, including Lewis-x (Lex) and sialyl Lewis-x (sLex), have previously been implicated in the regulation of important PMN functions, including selectin-mediated trafficking across vascular endothelium. Although glycans, such as Lex and sLex, which are based on the type 2 sequence (Galß1-4GlcNAc-R), are abundant on PMNs, the presence of type 1 Galß1-3GlcNAc-R glycans required for PMN expression of the closely related stereoisomer of Lex, termed Lewis-A (Lea), has not, to our knowledge, been reported. Here, we show that Lea is abundantly expressed by human PMNs and functionally regulates PMN migration. Using mAbs whose precise epitopes were determined using glycan array technology, Lea function was probed using Lea-selective mAbs and lectins, revealing increased PMN transmigration across model intestinal epithelia, which was independent of epithelial-expressed Lea Analyses of glycan synthetic machinery in PMNs revealed expression of ß1-3 galactosyltransferase and α1-4 fucosyltransferase, which are required for Lea synthesis. Specificity of functional effects observed after ligation of Lea was confirmed by failure of anti-Lea mAbs to enhance migration using PMNs from individuals deficient in α1-4 fucosylation. These results demonstrate that Lea is expressed on human PMNs, and its specific engagement enhances PMN migration responses. We propose that PMN Lea represents a new target for modulating inflammation and regulating intestinal, innate immunity.

Asunto(s)

Regulación de la Expresión Génica/inmunología , Inmunidad Innata , Inmunidad Mucosa , Neutrófilos/inmunología , Oligosacáridos/inmunología , Migración Transendotelial y Transepitelial/inmunología , Células CACO-2 , Técnicas de Cocultivo , Humanos , Antígenos del Grupo Sanguíneo de Lewis , Oligosacáridos/genética , Migración Transendotelial y Transepitelial/genética

RESUMEN

Polymorphonuclear neutrophils (PMNs) play a critical role in host defense against infection and in the resolution of inflammation. However, immune responses mediated by PMN must be tightly regulated to facilitate elimination of invading pathogens without inducing detrimental inflammation and host tissue damage. Specific engagement of cell surface immunoreceptors by a diverse range of extracellular signals regulates PMN effector functions through differential activation of intracellular signaling cascades. Although mechanisms of PMN activation mediated via cell signaling pathways have been well described, less is known about negative regulation of PMN function by immune signaling cascades. Here, we provide an overview of immunoreceptor-mediated negative regulation of key PMN effector functions including maturation, migration, phagocytosis, reactive oxygen species release, degranulation, apoptosis, and NET formation. Increased understanding of mechanisms of suppression of PMN effector functions may point to possible future therapeutic targets for the amelioration of PMN-mediated autoimmune and inflammatory diseases.

RESUMEN

The bone morphogenetic proteins (BMPs) regulate gastrointestinal homeostasis. We investigated the expression of BMP-4 and the localization and function of BMP signaling during colonic injury and inflammation. Mice expressing the ß-galactosidase (ß-gal) gene under the control of a BMP-responsive element (BRE), BMP-4-ß-gal/ mice, and animals generated by crossing villin-Cre mice to mice with floxed alleles of BMP receptor 1A (villin-Cre;Bmpr1aflox/flox) were treated with dextran sodium sulfate (DSS) to induce colonic injury and inflammation. Expression of BMP-4, ß-gal, BMPR1A, IL-8, α-smooth muscle actin, and phosphorylated Smad1, -5, and -8 was assessed by X-Gal staining, quantitative RT-PCR, and immunohistochemistry. Morphology of the colonic mucosa was examined by staining with hematoxylin and eosin. The effect of IFN-γ, TNF-α, IL-1ß, and IL-6 on BMP-4 mRNA expression was investigated in human intestinal fibroblasts, whereas that of BMP-4 on IL-8 was assessed in human colonic organoids. BMP-4 was localized in α-smooth muscle actin-positive mesenchymal cells while the majority of BMP-generated signals targeted the epithelium. DSS caused injury and inflammation leading to reduced expression of BMP-4 and of BMPR1A mRNAs, and to decreased BMP signaling. Deletion of BMPR1A enhanced colonic inflammation and damage. Administration of anti-TNF-α antibodies to DSS-treated mice ameliorated colonic inflammation and increased the expression of BMP-4 and BMPR1A mRNAs. TNF-α and IL-1ß inhibited both basal and IFN-γ-stimulated BMP-4 expression, whereas IL-6 had no effect. BMP-4 reduced TNF-α-stimulated IL-8 mRNA expressor IL-8 mRNA expression in the organoids. Inflammation and injury inhibit BMP-4 expression and signaling, leading to enhanced colonic damage and inflammation. These observations underscore the importance of BMP signaling in the regulation of intestinal inflammation and homeostasis. NEW & NOTEWORTHY: In this study we report a series of novel observations that underscore the importance of bone morphogenetic protein (BMP) signaling in the regulation of colonic homeostasis during the development of injury and inflammation. In particular, we present evidence that BMP signaling mitigates the response of the colonic epithelium to injury and inflammation and that cytokines, such as TNF-α and IL-1ß, inhibit the expression of BMP-4.

Asunto(s)

Proteína Morfogenética Ósea 4/metabolismo , Colon/metabolismo , Inflamación/metabolismo , Transducción de Señal/fisiología , Animales , Proteína Morfogenética Ósea 4/genética , Colon/efectos de los fármacos , Fibroblastos/efectos de los fármacos , Fibroblastos/metabolismo , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Interferón-alfa/farmacología , Interleucina-1beta/farmacología , Interleucina-6/farmacología , Interleucina-8/metabolismo , Ratones , Ratones Transgénicos , Factor de Necrosis Tumoral alfa/farmacología

RESUMEN

Polymorphonuclear neutrophils (PMNs) are innate immune system cells that play an essential role in eradicating invading pathogens. PMN migration to sites of infection/inflammation requires exiting the microcirculation and subsequent crossing of epithelial barriers in mucosa-lined organs such as the lungs and intestines. Although these processes usually occur without significant damage to surrounding host tissues, dysregulated/excessive PMN transmigration and resultant bystander-tissue damage are characteristic of numerous mucosal inflammatory disorders. Mechanisms controlling PMN extravasation have been well characterized, but the molecular details regarding regulation of PMN migration across mucosal epithelia are poorly understood. Given that PMN migration across mucosal epithelia is strongly correlated with disease symptoms in many inflammatory mucosal disorders, enhanced understanding of the mechanisms regulating PMN transepithelial migration should provide insights into clinically relevant tissue-targeted therapies aimed at ameliorating PMN-mediated bystander-tissue damage. This review will highlight current understanding of the molecular interactions between PMNs and mucosal epithelia and the associated functional consequences.

Asunto(s)

Movimiento Celular , Células Epiteliales/fisiología , Inmunidad Mucosa , Inflamación/inmunología , Neutrófilos/inmunología , Animales , Terapia Biológica , Comunicación Celular , Humanos , Infiltración Neutrófila