RESUMEN
Cross-regulation of Toll-like receptor (TLR) responses by cytokines is essential for effective host defense, avoidance of toxicity and homeostasis, but the underlying mechanisms are not well understood. Our comprehensive epigenomics approach to the analysis of human macrophages showed that the proinflammatory cytokines TNF and type I interferons induced transcriptional cascades that altered chromatin states to broadly reprogram responses induced by TLR4. TNF tolerized genes encoding inflammatory molecules to prevent toxicity while preserving the induction of genes encoding antiviral and metabolic molecules. Type I interferons potentiated the inflammatory function of TNF by priming chromatin to prevent the silencing of target genes of the transcription factor NF-κB that encode inflammatory molecules. The priming of chromatin enabled robust transcriptional responses to weak upstream signals. Similar chromatin regulation occurred in human diseases. Our findings reveal that signaling crosstalk between interferons and TNF is integrated at the level of chromatin to reprogram inflammatory responses, and identify previously unknown functions and mechanisms of action of these cytokines.
Asunto(s)
Epigénesis Genética , Inflamación/etiología , Inflamación/metabolismo , Interferón Tipo I/metabolismo , Macrófagos/inmunología , Macrófagos/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Sitios de Unión , Ensamble y Desensamble de Cromatina , Inmunoprecipitación de Cromatina , Análisis por Conglomerados , Biología Computacional/métodos , Citocinas/genética , Citocinas/metabolismo , Epigenómica/métodos , Perfilación de la Expresión Génica , Regulación de la Expresión Génica , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Lipopolisacáridos/inmunología , Lupus Eritematoso Sistémico/genética , Lupus Eritematoso Sistémico/inmunología , Lupus Eritematoso Sistémico/metabolismo , Monocitos/inmunología , Monocitos/metabolismo , Motivos de Nucleótidos , Regiones Promotoras Genéticas , Unión Proteica , Transporte de Proteínas , Transducción de Señal , Receptor Toll-Like 4/metabolismo , Factores de Transcripción/metabolismoRESUMEN
Cytokine tumor necrosis factor (TNF)-mediated macrophage polarization is important for inflammatory disease pathogenesis, but the mechanisms regulating polarization are not clear. We performed transcriptomic and epigenomic analysis of the TNF response in primary human macrophages and revealed late-phase activation of SREBP2, the master regulator of cholesterol biosynthesis genes. TNF stimulation extended the genomic profile of SREBP2 occupancy to include binding to and activation of inflammatory and interferon response genes independently of its functions in sterol metabolism. Genetic ablation of SREBP function shifted the balance of macrophage polarization from an inflammatory to a reparative phenotype in peritonitis and skin wound healing models. Genetic ablation of SREBP activity in myeloid cells or topical pharmacological inhibition of SREBP improved skin wound healing under homeostatic and chronic inflammatory conditions. Our results identify a function and mechanism of action for SREBPs in augmenting TNF-induced macrophage activation and inflammation and open therapeutic avenues for promoting wound repair.
Asunto(s)
Inflamación/metabolismo , Macrófagos/inmunología , Peritonitis/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Enfermedades de la Piel/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Animales , Diferenciación Celular , Células Cultivadas , Modelos Animales de Enfermedad , Epigenómica , Femenino , Humanos , Activación de Macrófagos , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Fenotipo , ARN Interferente Pequeño/genética , Receptores Acoplados a Proteínas G/genética , Transcriptoma , Cicatrización de HeridasRESUMEN
Mechanisms by which interferon (IFN)-γ activates genes to promote macrophage activation are well studied, but little is known about mechanisms and functions of IFN-γ-mediated gene repression. We used an integrated transcriptomic and epigenomic approach to analyze chromatin accessibility, histone modifications, transcription-factor binding, and gene expression in IFN-γ-primed human macrophages. IFN-γ suppressed basal expression of genes corresponding to an "M2"-like homeostatic and reparative phenotype. IFN-γ repressed genes by suppressing the function of enhancers enriched for binding by transcription factor MAF. Mechanistically, IFN-γ disassembled a subset of enhancers by inducing coordinate suppression of binding by MAF, lineage-determining transcription factors, and chromatin accessibility. Genes associated with MAF-binding enhancers were suppressed in macrophages isolated from rheumatoid-arthritis patients, revealing a disease-associated signature of IFN-γ-mediated repression. These results identify enhancer inactivation and disassembly as a mechanism of IFN-γ-mediated gene repression and reveal that MAF regulates the macrophage enhancer landscape and is suppressed by IFN-γ to augment macrophage activation.
Asunto(s)
Artritis Reumatoide/inmunología , Ensamble y Desensamble de Cromatina , Interferón gamma/metabolismo , Macrófagos/inmunología , Proteínas Proto-Oncogénicas c-maf/metabolismo , Diferenciación Celular , Linaje de la Célula , Células Cultivadas , Citocinas/metabolismo , Elementos de Facilitación Genéticos/genética , Regulación de la Expresión Génica , Histonas/metabolismo , Humanos , Unión Proteica , Proteínas Proto-Oncogénicas c-maf/genética , TranscriptomaRESUMEN
Hypoxia augments inflammatory responses and osteoclastogenesis by incompletely understood mechanisms. We identified COMMD1 as a cell-intrinsic negative regulator of osteoclastogenesis that is suppressed by hypoxia. In human macrophages, COMMD1 restrained induction of NF-κB signaling and a transcription factor E2F1-dependent metabolic pathway by the cytokine RANKL. Downregulation of COMMD1 protein expression by hypoxia augmented RANKL-induced expression of inflammatory and E2F1 target genes and downstream osteoclastogenesis. E2F1 targets included glycolysis and metabolic genes including CKB that enabled cells to meet metabolic demands in challenging environments, as well as inflammatory cytokine-driven target genes. Expression quantitative trait locus analysis linked increased COMMD1 expression with decreased bone erosion in rheumatoid arthritis. Myeloid deletion of Commd1 resulted in increased osteoclastogenesis in arthritis and inflammatory osteolysis models. These results identify COMMD1 and an E2F-metabolic pathway as key regulators of osteoclastogenic responses under pathological inflammatory conditions and provide a mechanism by which hypoxia augments inflammation and bone destruction.
Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Artritis Reumatoide/inmunología , Macrófagos/inmunología , Osteogénesis/genética , Proteínas Adaptadoras Transductoras de Señales/genética , Animales , Células Cultivadas , Modelos Animales de Enfermedad , Factor de Transcripción E2F1/metabolismo , Femenino , Humanos , Hipoxia/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Persona de Mediana Edad , FN-kappa B/metabolismo , ARN Interferente Pequeño/genética , Transducción de SeñalRESUMEN
Treating osteoporosis and associated bone fractures remains challenging for drug development in part due to potential off-target side effects and the requirement for long-term treatment. Here, we identify recombinant adeno-associated virus (rAAV)-mediated gene therapy as a complementary approach to existing osteoporosis therapies, offering long-lasting targeting of multiple targets and/or previously undruggable intracellular non-enzymatic targets. Treatment with a bone-targeted rAAV carrying artificial microRNAs (miRNAs) silenced the expression of WNT antagonists, schnurri-3 (SHN3), and sclerostin (SOST), and enhanced WNT/ß-catenin signaling, osteoblast function, and bone formation. A single systemic administration of rAAVs effectively reversed bone loss in both postmenopausal and senile osteoporosis. Moreover, the healing of bone fracture and critical-sized bone defects was also markedly improved by systemic injection or transplantation of AAV-bound allograft bone to the osteotomy sites. Collectively, our data demonstrate the clinical potential of bone-specific gene silencers to treat skeletal disorders of low bone mass and impaired fracture repair.
Asunto(s)
Fracturas Óseas , Osteoporosis , Humanos , Proteínas Adaptadoras Transductoras de Señales/genética , Osteoporosis/genética , Osteoporosis/terapia , Fracturas Óseas/genética , Fracturas Óseas/terapia , Huesos , Terapia GenéticaRESUMEN
Endotoxin tolerance, a key mechanism for suppressing excessive inflammatory cytokine production, is induced by prior exposure of macrophages to Toll-like receptor (TLR) ligands. Induction of cross-tolerance to endotoxin by endogenous cytokines has not been investigated. Here we show that prior exposure to tumor necrosis factor (TNF) induced a tolerant state in macrophages, with less cytokine production after challenge with lipopolysaccharide (LPS) and protection from LPS-induced death. TNF-induced cross-tolerization was mediated by suppression of LPS-induced signaling and chromatin remodeling. TNF-induced cross-tolerance was dependent on the kinase GSK3, which suppressed chromatin accessibility and promoted rapid termination of signaling via the transcription factor NF-κB by augmenting negative feedback by the signaling inhibitors A20 and IκBα. Our results demonstrate an unexpected homeostatic function for TNF and a GSK3-mediated mechanism for the prevention of prolonged and excessive inflammation.
Asunto(s)
Endotoxinas/inmunología , Glucógeno Sintasa Quinasa 3/inmunología , Macrófagos/inmunología , Factor de Necrosis Tumoral alfa/inmunología , Animales , Ensamble y Desensamble de Cromatina/efectos de los fármacos , Ensamble y Desensamble de Cromatina/inmunología , Cisteína Endopeptidasas/inmunología , Cisteína Endopeptidasas/metabolismo , Citocinas/biosíntesis , Citocinas/inmunología , Femenino , Proteínas I-kappa B/inmunología , Proteínas I-kappa B/metabolismo , Péptidos y Proteínas de Señalización Intracelular/inmunología , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Lipopolisacáridos/inmunología , Macrófagos/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos C57BL , Inhibidor NF-kappaB alfa , FN-kappa B/inmunología , FN-kappa B/metabolismo , Receptores Toll-Like/inmunología , Receptores Toll-Like/metabolismo , Proteína 3 Inducida por el Factor de Necrosis Tumoral alfaRESUMEN
Introduction: Breast reconstruction has become common after total mastectomy; however, certain types of breast reconstruction may be associated with delayed local recurrence or poor survival. Here, we investigated whether there are differences in the diagnosis and prognosis of local recurrence between autologous reconstruction and implant reconstruction. Materials and Methods: A retrospective analysis was performed on patients undergoing breast cancer surgery with autologous tissue or immediate implant reconstruction in a single center (January 2003-December 2017). Patient data including the period from cancer surgery to local recurrence diagnosis, tumor size at the time of recurrence, and survival time after cancer surgery and recurrence detection were analyzed. Results: There was a significant difference (p = 0.021) in the time from surgery to recurrence between the autologous tissue (1,246 days) and implant (909 days) groups. Recurrence tumor size did not differ (autologous: 1.00 cm2 vs. implant: 0.90 cm2; p = 0.813). Survival time after surgery (p = 0.63) and recurrence detection (p = 0.74) did not statistically significant. Conclusions: Statistical difference in the detection time was observed between autologous tissue and implant group. On the other hand, there is no difference in recurrence tumor size or survival time. A further study is necessary to identify the different detection time of local recurrence.
Asunto(s)
Implantes de Mama , Neoplasias de la Mama , Mamoplastia , Implantes de Mama/efectos adversos , Neoplasias de la Mama/patología , Femenino , Humanos , Mastectomía , Recurrencia Local de Neoplasia/cirugía , Pronóstico , Estudios RetrospectivosRESUMEN
BACKGROUND AND OBJECTIVES: Despite advances in medicine, infection at the surgical site is an impregnation problem that most surgeons confront. Although studies on the seasonality of infection have been conducted in various areas, no study has confirmed the relationship between seasonal temperature and infection after breast reconstruction. METHODS: From 2008 to 2018, a retrospective study was conducted on patients who underwent implant-based breast reconstruction. Patient demographics, intraoperative data, postoperative data, and temperature information were collected. Temperature differences between cases with and without infection were examined. The differences in the incidence and risk of infection by season were estimated according to the hot season (July to August) and the nonhot season (September to June). RESULTS: Of the 460 cases enrolled, 42 cases developed an infection. Among them, 15 (35.71%) cases developed infection during the hot season (P = 0.003). According to the logistic regression model, the risk of infection was 2.639 times higher in the hot season than in the nonhot season (95% confidence interval, 1.282-5.434; P = 0.008). When the temperature was higher than 25°C, the risk of infection increased by 45.2% for every 1°C increase, which was statistically significant (odds ratio, 1.452; 95% confidence interval, 1.198-1.76; P < 0.001). CONCLUSION: In conclusion, the hot season or average temperatures higher than 25°C increase the risk of infection in patients undergoing implant-based breast reconstruction. It is essential to focus on skin hygiene during the healing of the incision site.
Asunto(s)
Implantes de Mama , Neoplasias de la Mama , Mamoplastia , Implantes de Mama/efectos adversos , Femenino , Humanos , Mamoplastia/efectos adversos , Complicaciones Posoperatorias , Estudios Retrospectivos , Estaciones del Año , TemperaturaRESUMEN
BACKGROUND AND OBJECTIVES: Despite expander-based breast reconstruction being used as a reliable reconstruction method, implant removal due to wound dehiscence and infection still occurs in 0.5% to 15% of cases. This study aimed to compare the outcomes of the new inframammary fold (IMF) incision approach with previous incision in second-stage operation of expander-based 2-stage breast reconstruction. METHODS: Patients who underwent expander-based 2-stage breast reconstruction between February 2014 and May 2019 were included. After expander inflation, patients undergoing second-stage reconstruction were divided into the previous incision and IMF incision groups and their outcomes were compared. Propensity score matching analysis was performed to compare postoperative 1-year results. RESULTS: The previous incision and IMF incision groups comprised 79 and 31 patients, respectively. There were no intergroup differences in general demographics or intraoperative data, except for total inflation volume (426.87 ± 102.63 mL in the previous incision group and 375.48 ± 94.10 mL in the IMF incision group, P = 0.017). Wound dehiscence occurred in 12 and 0 cases in the previous and IMF incision groups, respectively (P = 0.018). Implant removal was performed due to dehiscence in 9 cases (8.18%) and 0 cases (0%) in the previous and IMF incision groups, respectively (P = 0.049). In 1-to-1 propensity score matching analysis, the IMF incision group showed better results at 1-year follow-up (odds ratio: 0, 95% confidence interval: 0-1.09; P = 0.063). CONCLUSIONS: The IMF approach is a safe method for replacing the expander with an implant, with lower incidence of wound dehiscence and implant explantation.
Asunto(s)
Implantes de Mama , Neoplasias de la Mama , Mamoplastia , Femenino , Humanos , Complicaciones Posoperatorias/epidemiología , Estudios Retrospectivos , Expansión de Tejido , Dispositivos de Expansión TisularRESUMEN
Rapid induction of inflammatory genes by tumor necrosis factor (TNF) has been well studied, but little is known about delayed and chronic TNF responses. Here we investigated the kinetics of primary macrophage responses to TNF and discovered that TNF initiates an interferon-beta-mediated autocrine loop that sustains expression of inflammatory genes and induces delayed expression of interferon-response genes such as those encoding the transcription factors STAT1 and IRF7, which enhance macrophage responses to stimulation of cytokines and Toll-like receptors. TNF-induced interferon-beta production depended on interferon-response factor 1, and downstream gene expression was mediated by synergy between small amounts of interferon-beta and canonical TNF-induced signals. Thus, TNF activates a 'feed-forward' loop that sustains inflammation but avoids the potential toxicity associated with the high interferon production induced by stimulation of Toll-like receptors.
Asunto(s)
Comunicación Autocrina/inmunología , Quimiocinas/biosíntesis , Quimiocinas/genética , Regulación de la Expresión Génica/inmunología , Factor 1 Regulador del Interferón/metabolismo , Interferón Tipo I/genética , Factor de Transcripción STAT1/fisiología , Factor de Necrosis Tumoral alfa/fisiología , Animales , Humanos , Mediadores de Inflamación/fisiología , Factor 1 Regulador del Interferón/fisiología , Interferón Tipo I/biosíntesis , Interferón Tipo I/fisiología , Interferón beta/biosíntesis , Interferón beta/genética , Interferón beta/fisiología , Macrófagos/metabolismo , Macrófagos/patología , Ratones , Factores de TiempoRESUMEN
Immunoreceptor tyrosine-based activation motif (ITAM)-coupled receptors modulate the amplitude and nature of macrophage responses to Toll-like receptor and cytokine receptor stimulation. However, the molecular mechanisms enabling this receptor crosstalk are not known. Here we investigated the function of the calcium-dependent kinases CaMK and Pyk2 'downstream' of ITAM-associated receptors in the regulation of cytokine-induced activation of Jak kinases and STAT transcription factors. CaMK and Pyk2 relayed signals from integrins and the ITAM-containing adaptor DAP12 to augment interleukin 10- and interferon-alpha-induced Jak activation and STAT1-dependent gene expression. CaMK inhibition suppressed STAT1-mediated interferon-alpha signaling in a mouse model of systemic lupus erythematosus. Our results associate Pyk2 and Jak kinases with the linkage of signals emanating from cytokine and heterologous ITAM-dependent receptors.
Asunto(s)
Quinasa de la Proteína Quinasa Dependiente de Calcio-Calmodulina/metabolismo , Quinasa 2 de Adhesión Focal/metabolismo , Interferón Tipo I/farmacología , Quinasas Janus/metabolismo , Macrófagos/efectos de los fármacos , Factor de Transcripción STAT1/metabolismo , Proteínas Adaptadoras Transductoras de Señales , Animales , Calcio/metabolismo , Células Cultivadas , Humanos , Macrófagos/inmunología , Proteínas de la Membrana , Ratones , Fosforilación , Receptores Inmunológicos/metabolismo , Transducción de Señal , Tirosina/metabolismoRESUMEN
An important function of immunoreceptor tyrosine-based activation motif (ITAM)-coupled receptors is cross-regulation of heterologous receptor signaling, but mechanisms of cross-inhibition are poorly understood. We show that high-avidity ligation of ITAM-coupled beta2 integrins and FcgammaRs in macrophages inhibited type I interferon receptor and Toll-like receptor (TLR) signaling and induced expression of interleukin-10 (IL-10); signaling inhibitors SOCS3, ABIN-3, and A20; and repressors of cytokine gene transcription STAT3 and Hes1. Induction of inhibitors was dependent on a pathway composed of signaling molecules DAP12, Syk, and Pyk2 that coupled to downstream kinases p38 and MSKs and required integration of IL-10-dependent and -independent signals. ITAM-induced inhibitors abrogated TLR responses by cooperatively targeting distinct steps in TLR signaling. Inhibitory signaling was suppressed by IFN-gamma and attenuated in inflammatory arthritis synovial macrophages. These results provide an indirect mechanism of cross-inhibition of TLRs and delineate a signaling pathway important for deactivation of macrophages.
Asunto(s)
Antígenos CD18/inmunología , Interferón Tipo I/inmunología , Receptores Inmunológicos/inmunología , Receptores Toll-Like/inmunología , Proteínas Adaptadoras Transductoras de Señales/deficiencia , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Animales , Células Cultivadas , Quinasa 2 de Adhesión Focal/metabolismo , Humanos , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Macrófagos/inmunología , Macrófagos/metabolismo , Ratones , Ratones Endogámicos C57BL , Proteínas Tirosina Quinasas/metabolismo , Transducción de Señal , Quinasa Syk , Receptores Toll-Like/metabolismoRESUMEN
Osteoclasts are bone-resorbing cells that play an essential role in bone remodeling. Defects in osteoclasts result in unbalanced bone remodeling and are linked to many bone diseases including osteoporosis, rheumatoid arthritis, primary bone cancer, and skeletal metastases. Receptor activator of NF-kappaB ligand (RANKL) is a classical inducer of osteoclast formation. In the presence of macrophage-colony-stimulating factor, RANKL and co-stimulatory signals synergistically regulate osteoclastogenesis. However, recent discoveries of alternative pathways for RANKL-independent osteoclastogenesis have led to a reassessment of the traditional mechanisms that regulate osteoclast formation. In this review, we provide an overview of signaling pathways and other regulatory elements governing osteoclastogenesis. We also identify how osteoclastogenesis is altered in pathological conditions and discuss therapeutic targets in osteoclasts for the treatment of skeletal diseases.
Asunto(s)
Remodelación Ósea , Resorción Ósea/metabolismo , Osteoblastos/metabolismo , Osteoclastos/metabolismo , Osteogénesis , Animales , Enfermedades Óseas/metabolismo , Humanos , Modelos Biológicos , Transducción de SeñalRESUMEN
Osteoclasts are resorptive cells that are important for homeostatic bone remodeling and pathological bone resorption. Emerging evidence suggests an important role for epigenetic mechanisms in osteoclastogenesis. A recent study showed that epigenetic silencing of the negative regulator of osteoclastogenesis Irf8 by DNA methylation is required for osteoclast differentiation. In this study, we investigated the role of EZH2, which epigenetically silences gene expression by histone methylation, in osteoclastogenesis. Inhibition of EZH2 by the small molecule GSK126, or decreasing its expression using antisense oligonucleotides, impeded osteoclast differentiation. Mechanistically, EZH2 was recruited to the IRF8 promoter after RANKL stimulation to deposit the negative histone mark H3K27me3 and downregulate IRF8 expression. GSK126 attenuated bone loss in the ovariectomy mouse model of postmenopausal osteoporosis. Our findings provide evidence for an additional mechanism of epigenetic IRF8 silencing during osteoclastogenesis that likely works cooperatively with DNA methylation, further emphasizing the importance of IRF8 as a negative regulator of osteoclastogenesis.
Asunto(s)
Diferenciación Celular/genética , Proteína Potenciadora del Homólogo Zeste 2/metabolismo , Silenciador del Gen , Factores Reguladores del Interferón/genética , Osteoclastos/citología , Osteoclastos/metabolismo , Osteogénesis/genética , Animales , Humanos , Factores Reguladores del Interferón/biosíntesis , Ratones , Ratones Endogámicos C3HRESUMEN
Phospholipase C gamma-2 (PLCγ2)-dependent calcium (Ca(2+)) oscillations are indispensable for nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1) activation and downstream gene transcription driving osteoclastogenesis during skeletal remodeling and pathological bone loss. Here we describe, to our knowledge, the first known function of transmembrane protein 178 (Tmem178), a PLCγ2 downstream target gene, as a critical modulator of the NFATc1 axis. In surprising contrast to the osteopetrotic phenotype of PLCγ2(-/-) mice, Tmem178(-/-) mice are osteopenic in basal conditions and are more susceptible to inflammatory bone loss, owing to enhanced osteoclast formation. Mechanistically, Tmem178 localizes to the ER membrane and regulates RANKL-induced Ca(2+) fluxes, thus controlling NFATc1 induction. Importantly, down-regulation of Tmem178 is observed in human CD14(+) monocytes exposed to plasma from systemic juvenile idiopathic arthritis patients. Similar to the mouse model, reduced Tmem178 expression in human cells correlates with excessive osteoclastogenesis. In sum, these findings identify an essential role for Tmem178 to maintain skeletal mass and limit pathological bone loss.
Asunto(s)
Retroalimentación Fisiológica , Proteínas de la Membrana/fisiología , Factores de Transcripción NFATC/fisiología , Osteoclastos/fisiología , Osteogénesis , Animales , Calcio/metabolismo , Células Cultivadas , Retículo Endoplásmico/metabolismo , Humanos , Ratones , Ratones Endogámicos C57BL , Monocitos/metabolismo , Fosfolipasa C gamma/fisiologíaRESUMEN
INTRODUCTION: LeFort III midface advancement using the distraction technique became the standard method for the correction of various craniofacial syndromes accompanied by the midface retrusion. Midface hypoplasia is known to be related to the imbalance in facial aesthetics, malocclusion, and the airway problem. This study aimed to evaluate the change in airway volume after performing a LeFort III midface advancement with the distraction techniques. PATIENTS AND METHODS: Between April 2008 and February 2013, 7 patients aged 5 to 7 years underwent standard LeFort III osteotomy, followed by distraction with a rigid external distractor with or without internal distractor. The degree of advancement of the midface and the airway volume were evaluated with 3-dimensional computed tomography scans and the 3-dimensional software. RESULTS: The average latent period was 3.57 days. The average manual distraction distance was 17.55 mm for 3.82 weeks. The consolidation period ranged from 3 to 7 months. Changes between the preoperative and postoperative airway volumes were remarkable. The average preoperative postpharyngeal airway volume was 5649.33 mm compared with an average postoperative airway volume of 7403.44 mm. Therefore, the average postpharyngeal airway space increased by a remarkable 32.78%. CONCLUSIONS: This investigation revealed that the LeFort III midface advancement using distraction could increase postpharyngeal airway space by approximately 33% when the midface is advanced by approximately 18 mm. This method could be used as a future reference for LeFort III midface advancement with distraction.
Asunto(s)
Obstrucción de las Vías Aéreas/cirugía , Disostosis Craneofacial/cirugía , Imagenología Tridimensional , Osteogénesis por Distracción , Osteotomía Le Fort , Tomografía Computarizada por Rayos X , Niño , Estética , Femenino , Humanos , Masculino , Resultado del TratamientoRESUMEN
Investigations on the therapeutic effects of intravenous immunoglobulin (IVIG) have focused on the suppression of autoantibody and immune complex-mediated inflammatory pathogenesis. Inflammatory diseases such as rheumatoid arthritis are often accompanied by excessive bone erosion but the effect of IVIG on osteoclasts, bone-resorbing cells, has not been studied. Here, we investigate whether IVIG directly regulates osteoclast differentiation and has therapeutic potential for suppressing osteoclast-mediated pathologic bone resorption. IVIG or cross-linking of Fcγ receptors with plate-bound IgG suppressed receptor activator of nuclear factor-κ B ligand (RANKL)-induced osteoclastogenesis and expression of osteoclast-related genes such as integrin ß3 and cathepsin K in a dose-dependent manner. Mechanistically, IVIG or plate-bound IgG suppressed osteoclastogenesis by downregulating RANKL-induced expression of NFATC1, the master regulator of osteoclastogenesis. IVIG suppressed NFATC1 expression by attenuating RANKL-induced NF-κB signaling, explained in part by induction of the inflammatory signaling inhibitor A20. IVIG administration attenuated in vivo osteoclastogenesis and suppressed bone resorption in the tumor necrosis factor (TNF)-induced calvarial osteolysis model. Our findings show that, in addition to suppressing inflammation, IVIG directly inhibits osteoclastogenesis through a mechanism involving suppression of RANK signaling. Direct suppression of osteoclast differentiation may provide beneficial effects on preserving bone mass when IVIG is used to treat rheumatic disorders.
Asunto(s)
Resorción Ósea/terapia , Cisteína Endopeptidasas/biosíntesis , Inmunoglobulinas Intravenosas/uso terapéutico , Péptidos y Proteínas de Señalización Intracelular/biosíntesis , Animales , Resorción Ósea/metabolismo , Resorción Ósea/patología , Diferenciación Celular , Modelos Animales de Enfermedad , Femenino , Ratones , Ratones Endogámicos C57BL , FN-kappa B/metabolismo , Factores de Transcripción NFATC/genética , Osteoclastos/efectos de los fármacos , Osteoclastos/metabolismo , Osteoclastos/patología , Ligando RANK/metabolismo , Enfermedades Reumáticas/metabolismo , Enfermedades Reumáticas/patología , Enfermedades Reumáticas/terapia , Transducción de Señal , Proteína 3 Inducida por el Factor de Necrosis Tumoral alfa , Factor de Necrosis Tumoral alfa/fisiologíaRESUMEN
OBJECTIVE: The nonresolving character of synovial inflammation in rheumatoid arthritis (RA) is a conundrum. To identify the contribution of fibroblast-like synoviocytes (FLS) to the perpetuation of synovitis, we investigated the molecular mechanisms that govern the tumor necrosis factor α (TNFα)-driven inflammatory program in human FLS. METHODS: FLS obtained from the synovial tissues of patients with RA or osteoarthritis were stimulated with TNFα and assayed for gene expression and cytokine production by real-time quantitative reverse transcription-polymerase chain reaction analysis and enzyme-linked immunosorbent assay. NF-κB signaling was evaluated by Western blotting. Histone acetylation, chromatin accessibility, and NF-κB p65 and RNA polymerase II (Pol II) occupancy at the interleukin-6 (IL-6) promoter were measured by chromatin immunoprecipitation and restriction enzyme accessibility assays. RESULTS: In FLS, TNFα induced prolonged transcription of messenger RNA (mRNA) for IL-6 and progressive accumulation of IL-6 protein over 4 days. Similarly, induction of mRNA for CXCL8/IL-8, CCL5/RANTES, matrix metalloproteinase 1 (MMP-1), and MMP-3 after TNFα stimulation was sustained for several days. This contrasted with the macrophage response to TNFα, which characteristically involved a transient increase in the expression of proinflammatory genes. In FLS, TNFα induced prolonged activation of NF-κB signaling and sustained transcriptional activity, as indicated by increased histone acetylation, chromatin accessibility, and p65 and Pol II occupancy at the IL-6 promoter. Furthermore, FLS expressed low levels of the feedback inhibitors A20-binding inhibitor of NF-κB activation 3 (ABIN-3), IL-1 receptor-associated kinase M (IRAK-M), suppressor of cytokine signaling 3 (SOCS-3), and activating transcription factor 3 (ATF-3), which terminate inflammatory responses in macrophages. CONCLUSION: TNFα signaling is not effectively terminated in FLS, which leads to an uncontrolled inflammatory response. The results suggest that prolonged and sustained inflammatory responses by FLS in response to synovial TNFα contribute to the persistence of synovial inflammation in RA.
Asunto(s)
Artritis Reumatoide/metabolismo , Citocinas/metabolismo , Fibroblastos/metabolismo , Mediadores de Inflamación/metabolismo , Inflamación/metabolismo , Membrana Sinovial/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Artritis Reumatoide/complicaciones , Artritis Reumatoide/genética , Estudios de Casos y Controles , Células Cultivadas , Citocinas/genética , Ensayo de Inmunoadsorción Enzimática , Fibroblastos/citología , Perfilación de la Expresión Génica , Humanos , Inflamación/complicaciones , Inflamación/genética , Macrófagos/metabolismo , Osteoartritis/genética , Osteoartritis/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Membrana Sinovial/citología , Activación TranscripcionalRESUMEN
ITAM-coupled receptors play an essential role in regulating macrophage activation and function by cross-regulating signaling from heterologous receptors. We investigated mechanisms by which ITAM-associated receptors inhibit type I IFN (IFN-α/ß) signaling in primary human macrophages and tested the effects of simultaneous ligation of ITAM-associated receptors and TLR4 on TLR4-induced Jak-STAT signaling that is mediated by autocrine IFN-ß. Preligation of ITAM-coupled ß2 integrins and FcγRs inhibited proximal signaling by the type I IFN receptor IFNAR. Cross-inhibition of IFNAR signaling by ß2 integrins resulted in decreased Jak1 activation and was mediated by partial downregulation of the IFNAR1 subunit and MAPK-dependent induction of USP18, which blocks the association of Jak1 with IFNAR2. Simultaneous engagement of ITAM-coupled ß2 integrins or Dectin-1 with TLR4 did not affect TLR4-induced direct activation of inflammatory target genes such as TNF or IL6 but abrogated subsequent induction of IFN response genes that is mediated by autocrine IFN-ß signaling. Type I IFNs promote macrophage death postinfection by Listeria monocytogenes. Consequently, attenuation of IFN responses by ß2 integrins protected primary human macrophages from L. monocytogenes-induced apoptosis. These results provide a mechanism for cross-inhibition of type I IFN signaling by ITAM-coupled ß2 integrins and demonstrate that ITAM signaling qualitatively modulates macrophage responses to pathogen-associated molecular patterns and pathogens by selectively suppressing IFN responses.