RESUMEN
To define the cell populations that drive joint inflammation in rheumatoid arthritis (RA), we applied single-cell RNA sequencing (scRNA-seq), mass cytometry, bulk RNA sequencing (RNA-seq) and flow cytometry to T cells, B cells, monocytes, and fibroblasts from 51 samples of synovial tissue from patients with RA or osteoarthritis (OA). Utilizing an integrated strategy based on canonical correlation analysis of 5,265 scRNA-seq profiles, we identified 18 unique cell populations. Combining mass cytometry and transcriptomics revealed cell states expanded in RA synovia: THY1(CD90)+HLA-DRAhi sublining fibroblasts, IL1B+ pro-inflammatory monocytes, ITGAX+TBX21+ autoimmune-associated B cells and PDCD1+ peripheral helper T (TPH) cells and follicular helper T (TFH) cells. We defined distinct subsets of CD8+ T cells characterized by GZMK+, GZMB+, and GNLY+ phenotypes. We mapped inflammatory mediators to their source cell populations; for example, we attributed IL6 expression to THY1+HLA-DRAhi fibroblasts and IL1B production to pro-inflammatory monocytes. These populations are potentially key mediators of RA pathogenesis.
Asunto(s)
Artritis Reumatoide/genética , Artritis Reumatoide/metabolismo , Perfilación de la Expresión Génica , Membrana Sinovial/metabolismo , Transcriptoma , Artritis Reumatoide/patología , Autoinmunidad/genética , Biomarcadores , Biología Computacional/métodos , Estudios Transversales , Citocinas/metabolismo , Fibroblastos/metabolismo , Citometría de Flujo , Expresión Génica , Perfilación de la Expresión Génica/métodos , Secuenciación de Nucleótidos de Alto Rendimiento , Antígenos de Histocompatibilidad Clase II/genética , Antígenos de Histocompatibilidad Clase II/inmunología , Humanos , Leucocitos/inmunología , Leucocitos/metabolismo , Monocitos/inmunología , Monocitos/metabolismo , Transducción de Señal , Análisis de la Célula Individual/métodos , Membrana Sinovial/patología , Subgrupos de Linfocitos T/inmunología , Subgrupos de Linfocitos T/metabolismo , Flujo de TrabajoRESUMEN
Rheumatoid arthritis is a prototypical autoimmune disease that causes joint inflammation and destruction1. There is currently no cure for rheumatoid arthritis, and the effectiveness of treatments varies across patients, suggesting an undefined pathogenic diversity1,2. Here, to deconstruct the cell states and pathways that characterize this pathogenic heterogeneity, we profiled the full spectrum of cells in inflamed synovium from patients with rheumatoid arthritis. We used multi-modal single-cell RNA-sequencing and surface protein data coupled with histology of synovial tissue from 79 donors to build single-cell atlas of rheumatoid arthritis synovial tissue that includes more than 314,000 cells. We stratified tissues into six groups, referred to as cell-type abundance phenotypes (CTAPs), each characterized by selectively enriched cell states. These CTAPs demonstrate the diversity of synovial inflammation in rheumatoid arthritis, ranging from samples enriched for T and B cells to those largely lacking lymphocytes. Disease-relevant cell states, cytokines, risk genes, histology and serology metrics are associated with particular CTAPs. CTAPs are dynamic and can predict treatment response, highlighting the clinical utility of classifying rheumatoid arthritis synovial phenotypes. This comprehensive atlas and molecular, tissue-based stratification of rheumatoid arthritis synovial tissue reveal new insights into rheumatoid arthritis pathology and heterogeneity that could inform novel targeted treatments.
Asunto(s)
Artritis Reumatoide , Humanos , Artritis Reumatoide/complicaciones , Artritis Reumatoide/genética , Artritis Reumatoide/inmunología , Artritis Reumatoide/patología , Citocinas/metabolismo , Inflamación/complicaciones , Inflamación/genética , Inflamación/inmunología , Inflamación/patología , Membrana Sinovial/patología , Linfocitos T/inmunología , Linfocitos B/inmunología , Predisposición Genética a la Enfermedad/genética , Fenotipo , Análisis de Expresión Génica de una Sola CélulaRESUMEN
BACKGROUND: Chimeric antigen receptor (CAR)-T cells have been used to treat blood cancers by producing a wide variety of cytokines. However, they are not effective in treating solid cancers and can cause severe side-effects, including cytokine release syndrome. TNFα is a tumoricidal cytokine, but it markedly increases the protein levels of cIAP1 and cIAP2, the members of inhibitor of apoptosis protein (IAP) family of E3 ubiquitin ligase that limits caspase-induced apoptosis. Degradation of IAP proteins by an IAP antagonist does not effectively kill cancer cells but enables TNFα to strongly induce cancer cell apoptosis. It would be a promising approach to treat cancers by targeted delivery of TNFα through an inactive adoptive cell in combination with an IAP antagonist. METHODS: Human dendritic cells (DCs) were engineered to express a single tumoricidal factor, TNFα, and a membrane-anchored Mucin1 antibody scFv, named Mucin 1 directed DCs expressing TNFα (M-DCsTNF). The efficacy of M-DCsTNF in recognizing and treating breast cancer was tested in vitro and in vivo. RESULTS: Mucin1 was highly expressed on the surface of a wide range of human breast cancer cell lines. M-DCsTNF directly associated with MDA-MB-231 cells in the bone of NSG mice. M-DCsTNF plus an IAP antagonist, SM-164, but neither alone, markedly induce MDA-MB-231 breast cancer cell apoptosis, which was blocked by TNF antibody. Importantly, M-DCsTNF combined with SM-164, but not SM-164 alone, inhibited the growth of patient-derived breast cancer in NSG mice. CONCLUSION: An adoptive cell targeting delivery of TNFα combined with an IAP antagonist is a novel effective approach to treat breast cancer and could be expanded to treat other solid cancers. Unlike CAR-T cell, this novel adoptive cell is not activated to produce a wide variety of cytokines, except for additional overexpressed TNF, and thus could avoid the severe side effects such as cytokine release syndrome.
Asunto(s)
Células Dendríticas , Receptores Quiméricos de Antígenos , Factor de Necrosis Tumoral alfa , Humanos , Animales , Ratones , Células Dendríticas/inmunología , Células Dendríticas/metabolismo , Femenino , Receptores Quiméricos de Antígenos/inmunología , Factor de Necrosis Tumoral alfa/metabolismo , Mucina-1/inmunología , Mucina-1/metabolismo , Ensayos Antitumor por Modelo de Xenoinjerto , Línea Celular Tumoral , Proteínas Inhibidoras de la Apoptosis/antagonistas & inhibidores , Proteínas Inhibidoras de la Apoptosis/metabolismo , Inmunoterapia Adoptiva/métodos , Apoptosis , Neoplasias de la Mama/terapia , Neoplasias de la Mama/inmunología , Inmunoterapia/métodos , Neoplasias/terapia , Neoplasias/inmunología , Ratones SCIDRESUMEN
BACKGROUND: Synovial tissue research has become widely developed in several rheumatology centres, however, large discrepancies exist in the way synovial tissue is handled and, more specifically, how data pertaining to biopsy procedure, quality check and experimental results are reported in the literature. This heterogeneity hampers the progress of research in this rapidly expanding field. In that context, under the umbrella of European Alliance of Associations for Rheumatology, we aimed at proposing points to consider (PtC) for minimal reporting requirements in synovial tissue research. METHODS: Twenty-five members from 10 countries across Europe and USA met virtually to define the key areas needing evaluation and formulating the research questions to inform a systematic literature review (SLR). The results were presented during a second virtual meeting where PtC were formulated and agreed. RESULTS: Study design, biopsy procedures, tissue handling, tissue quality control and tissue outcomes (imaging, DNA/RNA analysis and disaggregation) were identified as important aspects for the quality of synovial tissue research. The SLR interrogated four databases, retrieved 7654 abstracts and included 26 manuscripts. Three OPs and nine PtC were formulated covering the following areas: description of biopsy procedure, overarching clinical design, patient characteristics, tissue handling and processing, quality control, histopathology, transcriptomic analyses and single-cell technologies. CONCLUSIONS: These PtC provide guidance on how research involving synovial tissue should be reported to ensure a better evaluation of results by readers, reviewers and the broader scientific community. We anticipate that these PtC will enable the field to progress in a robust and transparent manner over the coming years.
Asunto(s)
Reumatología , Humanos , Membrana Sinovial/patología , Biopsia/métodos , Europa (Continente)RESUMEN
NF-κB and Notch signaling can be simultaneously activated in a variety of B-cell lymphomas. Patients with B-cell lymphoma occasionally develop clonally related myeloid tumors with poor prognosis. Whether concurrent activation of both pathways is sufficient to induce B-cell transformation and whether the signaling initiates B-myeloid conversion in a pathological context are largely unknown. Here, we provide genetic evidence that concurrent activation of NF-κB and Notch signaling in committed B cells is sufficient to induce B-cell lymphomatous transformation and primes common progenitor cells to convert to myeloid lineage through dedifferentiation, not transdifferentiation. Intriguingly, the converted myeloid cells can further transform, albeit at low frequency, into myeloid leukemia. Mechanistically, coactivation of NF-κB and Notch signaling endows committed B cells with the ability to self renew. Downregulation of BACH2, a lymphoma and myeloid gene suppressor, but not upregulation of CEBPα and/or downregulation of B-cell transcription factors, is an early event in both B-cell transformation and myeloid conversion. Interestingly, a DNA hypomethylating drug not only effectively eliminated the converted myeloid leukemia cells, but also restored the expression of green fluorescent protein, which had been lost in converted myeloid leukemia cells. Collectively, our results suggest that targeting NF-κB and Notch signaling will not only improve lymphoma treatment, but also prevent the lymphoma-to-myeloid tumor conversion. Importantly, DNA hypomethylating drugs might efficiently treat these converted myeloid neoplasms.
Asunto(s)
Linfocitos B/patología , Transformación Celular Neoplásica/patología , Linfoma de Células B de la Zona Marginal/patología , Células Mieloides/patología , FN-kappa B/metabolismo , Receptores Notch/metabolismo , Animales , Linfocitos B/metabolismo , Transformación Celular Neoplásica/metabolismo , Femenino , Humanos , Linfoma de Células B de la Zona Marginal/genética , Linfoma de Células B de la Zona Marginal/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Células Mieloides/metabolismo , FN-kappa B/genética , Receptores Notch/genética , Transducción de SeñalRESUMEN
Macrophages play critical roles in homeostasis and inflammation. Macrophage polarization to either a pro-inflammatory or anti-inflammatory status is controlled by activating inflammatory signaling pathways. Ubiquitination is a posttranslational modification that regulates these inflammatory signaling pathways. However, the influence of protein ubiquitination on macrophage polarization has not been well studied. We hypothesized that the ubiquitination status of key proteins in inflammatory pathways contributes to macrophage polarization, which is regulated by itchy E3 ubiquitin ligase (ITCH), a negative regulator of inflammation. Using ubiquitin proteomics, we found that ubiquitination profiles are different among polarized murine macrophage subsets. Interestingly, interleukin-1α (IL-1α), an important pro-inflammatory mediator, was specifically ubiquitinated in lipopolysaccharide-induced pro-inflammatory macrophages, which was enhanced in ITCH-deficient macrophages. The ITCH-deficient macrophages had increased levels of the mature form of IL-1α and exhibited pro-inflammatory polarization, and reduced deubiquitination of IL-1α protein. Finally, IL-1α neutralization attenuated pro-inflammatory polarization of the ITCH-deficient macrophages. In conclusion, ubiquitination of IL-1α is associated with increased pro-inflammatory polarization of macrophages deficient in the E3 ligase ITCH.
Asunto(s)
Interleucina-1alfa/metabolismo , Macrófagos/metabolismo , Ubiquitina-Proteína Ligasas/genética , Ubiquitinación , Animales , Células Cultivadas , Femenino , Eliminación de Gen , Inflamación/genética , Inflamación/metabolismo , Macrófagos/citología , Masculino , Ratones Endogámicos C57BL , Ubiquitina/metabolismoRESUMEN
NF-κB signals through canonical transcription factor p65 (RelA)/p50 and noncanonical avian reticuloendotheliosis viral oncogene related B (RelB)/p52 pathways. The RelA/p50 is involved in basal and inflammatory lymphangiogenesis. However, the role of RelB/p52 in lymphatic vessel biology is unknown. Herein, we investigated changes in lymphatic vessels (LVs) in mice deficient in noncanonical NF-κB signaling and the function of RelB in lymphatic endothelial cells (LECs). LVs were examined in Relb-/-, p52-/-, or control mice, and the gene expression profiles in LECs with RelB knockdown. Relb-/-, but not p52-/-, mice exhibited multiple LV abnormalities. They include the following: i) increased capillary vessel diameter, ii) reduced smooth muscle cell (SMC) coverage of mature vessels, iii) leakage, and iv) loss of active and passive lymphatic flow. Relb-/- mature LVs had thinner vessel walls, more apoptotic LECs and SMCs, and fewer LEC junctions. RelB knockdown LECs had decreased growth, survival, and adhesion, and dysregulated signaling pathways involving these cellular events. These results suggest that Relb-/- mice have abnormal LVs, mainly in mature vessels with reduced SMC coverage, leakage, and loss of contractions. RelB knockdown in LECs leads to reduced growth, survival, and adhesion. RelB plays a vital role in LEC-mediated LV maturation and function.
Asunto(s)
Proliferación Celular , Células Endoteliales/patología , Vasos Linfáticos/patología , Factor de Transcripción ReIB/fisiología , Animales , Apoptosis , Movimiento Celular , Células Cultivadas , Células Endoteliales/metabolismo , Vasos Linfáticos/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , FN-kappa B , Transducción de SeñalRESUMEN
Cytokines, including receptor activator of nuclear factor κB ligand (RANKL) and TNF, induce increased osteoclast (OC) formation and bone loss in postmenopausal osteoporosis and inflammatory arthritides. RANKL and TNF can independently induce OC formation in vitro from WT OC precursors via TNF receptor-associated factor (TRAF) adaptor proteins, which bind to their receptors. Of these, only TRAF6 is required for RANKL-induced osteoclastogenesis in vitro However, the molecular mechanisms involved remain incompletely understood. Here we report that RANKL induced the formation of bone-resorbing OCs from TRAF6-/- OC precursors when cultured on bone slices but not on plastic. The mechanisms involved increased TNF production by TRAF6-/- OC precursors resulting from their interaction with bone matrix and release of active TGFß from the resorbed bone, coupled with RANKL-induced autophagolysosomal degradation of TRAF3, a known inhibitor of OC formation. Consistent with these findings, RANKL enhanced TNF-induced OC formation from TRAF6-/- OC precursors. Moreover, TNF induced significantly more OCs from mice with TRAF3 conditionally deleted in myeloid lineage cells, and it did not inhibit RANKL-induced OC formation from these cells. TRAF6-/- OC precursors that overexpressed TRAF3 or were treated with the autophagolysosome inhibitor chloroquine formed significantly fewer OCs in response to TNF alone or in combination with RANKL. We conclude that RANKL can enhance TNF-induced OC formation independently of TRAF6 by degrading TRAF3. These findings suggest that preventing TRAF3 degradation with drugs like chloroquine could reduce excessive OC formation in diseases in which bone resorption is increased in response to elevated production of these cytokines.
Asunto(s)
Huesos/metabolismo , Osteoclastos/metabolismo , Osteogénesis , Ligando RANK/metabolismo , Factor 3 Asociado a Receptor de TNF/metabolismo , Factor 6 Asociado a Receptor de TNF/metabolismo , Factor de Necrosis Tumoral alfa/agonistas , Citoesqueleto de Actina/inmunología , Citoesqueleto de Actina/metabolismo , Citoesqueleto de Actina/patología , Animales , Antiinflamatorios no Esteroideos/farmacología , Autofagia/efectos de los fármacos , Desmineralización Ósea Patológica/inmunología , Desmineralización Ósea Patológica/metabolismo , Desmineralización Ósea Patológica/patología , Huesos/efectos de los fármacos , Huesos/inmunología , Huesos/patología , Técnicas de Cultivo de Célula , Células Cultivadas , Cloroquina/farmacología , Ratones , Ratones Noqueados , Osteoclastos/efectos de los fármacos , Osteoclastos/inmunología , Osteoclastos/patología , Osteogénesis/efectos de los fármacos , Estabilidad Proteica/efectos de los fármacos , Proteolisis/efectos de los fármacos , Ligando RANK/genética , Bazo/citología , Bazo/inmunología , Bazo/metabolismo , Factor 3 Asociado a Receptor de TNF/genética , Factor 6 Asociado a Receptor de TNF/genética , Factor de Necrosis Tumoral alfa/genética , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
The secreted protein, YKL-40, has been proposed as a biomarker of a variety of human diseases characterized by ongoing inflammation, including chronic neurologic pathologies such as multiple sclerosis and Alzheimer's disease. However, inflammatory mediators and the molecular mechanism responsible for enhanced expression of YKL-40 remained elusive. Using several mouse models of inflammation, we now show that YKL-40 expression correlated with increased expression of both IL-1 and IL-6. Furthermore, IL-1 together with IL-6 or the IL-6 family cytokine, oncostatin M, synergistically upregulated YKL-40 expression in both primary human and mouse astrocytes in vitro. The robust cytokine-driven expression of YKL-40 in astrocytes required both STAT3 and NF-κB binding elements of the YKL-40 promoter. In addition, YKL-40 expression was enhanced by constitutively active STAT3 and inhibited by dominant-negative IκBα. Surprisingly, cytokine-driven expression of YKL-40 in astrocytes was independent of the p65 subunit of NF-κB and instead required subunits RelB and p50. Mechanistically, we show that IL-1-induced RelB/p50 complex formation was further promoted by oncostatin M and that these complexes directly bound to the YKL-40 promoter. Moreover, we found that expression of RelB was strongly upregulated during inflammation in vivo and by IL-1 in astrocytes in vitro. We propose that IL-1 and the IL-6 family of cytokines regulate YKL-40 expression during sterile inflammation via both STAT3 and RelB/p50 complexes. These results suggest that IL-1 may regulate the expression of specific anti-inflammatory genes in nonlymphoid tissues via the canonical activation of the RelB/p50 complexes.
Asunto(s)
Adipoquinas/genética , Citocinas/farmacología , Expresión Génica/efectos de los fármacos , Glicoproteínas/genética , Lectinas/genética , Subunidad p50 de NF-kappa B/metabolismo , Factor de Transcripción ReIB/metabolismo , Adipoquinas/metabolismo , Animales , Astrocitos/efectos de los fármacos , Astrocitos/metabolismo , Western Blotting , Línea Celular Tumoral , Células Cultivadas , Proteína 1 Similar a Quitinasa-3 , Citocinas/genética , Femenino , Glicoproteínas/metabolismo , Humanos , Inflamación/genética , Inflamación/metabolismo , Interleucina-1/genética , Interleucina-1/farmacología , Interleucina-6/genética , Interleucina-6/farmacología , Lectinas/metabolismo , Masculino , Ratones Endogámicos C57BL , Ratones Transgénicos , Complejos Multiproteicos/metabolismo , Subunidad p50 de NF-kappa B/genética , Oncostatina M/farmacología , Regiones Promotoras Genéticas/genética , Unión Proteica/efectos de los fármacos , Interferencia de ARN , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factor de Transcripción STAT3/metabolismo , Factor de Transcripción ReIB/genéticaRESUMEN
Chronic metabolic acidosis stimulates cell-mediated calcium efflux from bone through osteoblastic prostaglandin E2-induced stimulation of receptor activator of NF-kB ligand leading to increased osteoclastic bone resorption. Osteoblasts express the proton-sensing G-protein-coupled receptor OGR1, which activates inositol phosphate-mediated intracellular calcium. Proton-induced osteoblastic intracellular calcium signaling requires ovarian cancer G-protein-coupled receptor 1 (OGR1), suggesting that OGR1 is the sensor activated during acidosis to cause bone resorption. Growing mice produce large amounts of metabolic acids, which must be buffered, primarily by bone, before excretion by the kidney. Here we tested whether lack of OGR1 inhibits proton-induced bone resorption by measuring bone mineral density by micro-computed tomography and histomorphometry in 8-week-old male OGR1(-/-) and C57/Bl6 wild type mice. OGR1(-/-) mice have normal skeletal development with no atypical gross phenotype. Trabecular and cortical bone volume was increased in tibiae and vertebrae from OGR1(-/-). There were increased osteoblast numbers on the cortical and trabecular surfaces of tibiae from OGR1(-/-) mice, increased endocortical and trabecular bone formation rates, and osteoblastic gene expression. Osteoclast numbers and surface were increased in tibiae of OGR1(-/-) mice. Thus, in rapidly growing mice, lack of OGR1 leads to increased bone mass with increased bone turnover and a greater increase in bone formation than resorption. This supports the important role of the proton receptor OGR1 in the response of bone to protons.
Asunto(s)
Densidad Ósea , Osteoblastos/metabolismo , Osteogénesis , Receptores Acoplados a Proteínas G/deficiencia , Tibia/metabolismo , Animales , Densidad Ósea/genética , Proliferación Celular , Células Cultivadas , Regulación de la Expresión Génica , Genotipo , Concentración de Iones de Hidrógeno , Masculino , Ratones Endogámicos C57BL , Ratones Noqueados , Osteogénesis/genética , Fenotipo , Receptores Acoplados a Proteínas G/genética , Tibia/diagnóstico por imagen , Factores de Tiempo , Microtomografía por Rayos XRESUMEN
Obesity is a severe health problem in children, afflicting several organ systems including bone. However, the role of obesity on bone homeostasis and bone cell function in children has not been studied in detail. Here we used young mice fed a high-fat diet (HFD) to model childhood obesity and investigate the effect of HFD on the phenotype of cells within the bone marrow environment. Five-week-old male mice were fed a HFD for 3, 6, and 12 weeks. Decreased bone volume was detected after 3 weeks of HFD treatment. After 6 and 12 weeks, HFD-exposed mice had less bone mass and increased osteoclast numbers. Bone marrow cells, but not spleen cells, from HFD-fed mice had increased osteoclast precursor frequency, elevated osteoclast formation, and bone resorption activity, as well as increased expression of osteoclastogenic regulators including RANKL, TNF, and PPAR-gamma. Bone formation rate and osteoblast and adipocyte numbers were also increased in HFD-fed mice. Isolated bone marrow cells also had a corresponding elevation in the expression of positive regulators of osteoblast and adipocyte differentiation. Our findings indicate that in juvenile mice, HFD-induced bone loss is mainly due to increased osteoclast bone resorption by affecting the bone marrow microenvironment. Thus, targeting osteoclast formation may present a new therapeutic approach for bone complications in obese children.
Asunto(s)
Médula Ósea/patología , Resorción Ósea/fisiopatología , Dieta Alta en Grasa/efectos adversos , Osteoclastos/citología , Adipocitos/citología , Animales , Biomarcadores/sangre , Glucemia/análisis , Densidad Ósea , Médula Ósea/metabolismo , Huesos/patología , Diferenciación Celular , Separación Celular , Citometría de Flujo , Antígenos Comunes de Leucocito/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Obesidad/metabolismo , Osteoblastos/citología , Osteoclastos/metabolismo , PPAR gamma/metabolismo , Ligando RANK/metabolismo , Bazo/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Microtomografía por Rayos XRESUMEN
Itch is a ubiquitin E3 ligase that regulates protein stability. Itch(-/-) mice develop an autoimmune disease phenotype characterized by itchy skin and multiorgan inflammation. The role of Itch in the regulation of osteoclast function has not been examined. We report that Itch(-/-) bone marrow and spleen cells formed more osteoclasts than cells from WT littermates in response to receptor activator of NF-κB ligand (RANKL) and was associated with increased expression of the osteoclastogenic transcription factors c-fos and Nfatc1. Overexpression of Itch in Itch(-/-) cells rescued increased osteoclastogenesis. RANKL increased Itch expression, which can be blocked by a NF-κB inhibitor. The murine Itch promoter contains NF-κB binding sites. Overexpression of NF-κB p65 increased Itch expression, and RANKL promoted the binding of p65 onto the NF-κB binding sites in the Itch promoter. Itch(-/-) osteoclast precursors had prolonged RANKL-induced NF-κB activation and delayed TNF receptor-associated factor 6 (TRAF6) deubiquitination. In WT osteoclast precursors, Itch bound to TRAF6 and the deubiquitinating enzyme cylindromatosis. Adult Itch(-/-) mice had normal bone volume, but they had significantly increased LPS-induced osteoclastogenesis and bone resorption. Thus, Itch is a new RANKL target gene that is induced during osteoclastogenesis. Itch interacts with the deubiquitinating enzyme and is required for deubiquitination of TRAF6, thus limiting RANKL-induced osteoclast formation.
Asunto(s)
Osteoclastos/citología , Factor 6 Asociado a Receptor de TNF/metabolismo , Ubiquitina-Proteína Ligasas/fisiología , Animales , Secuencia de Bases , Cartilla de ADN , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , FN-kappa B/metabolismo , Reacción en Cadena de la Polimerasa , Ligando RANK/metabolismo , Transducción de Señal , UbiquitinaciónRESUMEN
Osteoporosis is incurable because there are no dual antiresorptive and anabolic therapeutic agents that can be administered long-term. The most widely used antiresorptive agents, bisphosphonates (BPs), also inhibit bone formation and thus have limited effect in preventing osteoporotic fracture. Hydroxychloroquine (HCQ), which is used to treat rheumatoid arthritis, prevents the lysosomal degradation of TNF receptor-associated factor 3 (TRAF3), an NF-κB adaptor protein that limits bone resorption and maintains bone formation. We attempted to covalently link HCQ to a hydroxyalklyl BP (HABP) with anticipated low antiresorptive activity, to target delivery of HCQ to bone to test if this targeting increases its efficacy to prevent TRAF3 degradation in the bone microenvironment and thus reduce bone resorption and increase bone formation, while reducing its systemic side effects. Unexpectedly, HABP-HCQ was found to exist as a salt in aqueous solution, composed of a protonated HCQ cation and a deprotonated HABP anion. Nevertheless, it inhibited osteoclastogenesis, stimulated osteoblast differentiation, and increased TRAF3 protein levels in vitro. HABP-HCQ significantly inhibited both osteoclast formation and bone marrow fibrosis in mice given multiple daily PTH injections. In contrast, HCQ inhibited fibrosis, but not osteoclast formation, while the HABP alone inhibited osteoclast formation, but not fibrosis, in the mice. HABP-HCQ, but not HCQ, prevented trabecular bone loss following ovariectomy in mice and, importantly, increased bone volume in ovariectomized mice with established bone loss because HABP-HCQ increased bone formation and decreased bone resorption parameters simultaneously. In contrast, HCQ increased bone formation, but did not decrease bone resorption parameters, while HABP also restored the bone lost in ovariectomized mice, but it inhibited parameters of both bone resorption and formation. Our findings suggest that the combination of HABP and HCQ could have dual antiresorptive and anabolic effects to prevent and treat osteoporosis.
RESUMEN
Osteoporosis remains incurable. The most widely used antiresorptive agents, bisphosphonates (BPs), also inhibit bone formation, while the anabolic agent, teriparatide, does not inhibit bone resorption, and thus they have limited efficacy in preventing osteoporotic fractures and cause some side effects. Thus, there is an unmet need to develop dual antiresorptive and anabolic agents to prevent and treat osteoporosis. Hydroxychloroquine (HCQ), which is used to treat rheumatoid arthritis, prevents the lysosomal degradation of TNF receptor-associated factor 3 (TRAF3), an NF-κB adaptor protein that limits bone resorption and maintains bone formation. We attempted to covalently link HCQ to a hydroxyalklyl BP (HABP) with anticipated low antiresorptive activity, to target delivery of HCQ to bone to test if this targeting increases its efficacy to prevent TRAF3 degradation in the bone microenvironment and thus reduce bone resorption and increase bone formation, while reducing its systemic side effects. Unexpectedly, HABP-HCQ was found to exist as a salt in aqueous solution, composed of a protonated HCQ cation and a deprotonated HABP anion. Nevertheless, it inhibited osteoclastogenesis, stimulated osteoblast differentiation, and increased TRAF3 protein levels in vitro. HABP-HCQ significantly inhibited both osteoclast formation and bone marrow fibrosis in mice given multiple daily PTH injections. In contrast, HCQ inhibited marrow fibrosis, but not osteoclast formation, while the HABP alone inhibited osteoclast formation, but not fibrosis, in the mice. HABP-HCQ, but not HCQ, prevented trabecular bone loss following ovariectomy in mice and, importantly, increased bone volume in ovariectomized mice with established bone loss because HABP-HCQ increased bone formation and decreased bone resorption parameters simultaneously. In contrast, HCQ increased bone formation, but did not decrease bone resorption parameters, while HABP also restored the bone lost in ovariectomized mice, but it inhibited parameters of both bone resorption and formation. Our findings suggest that the combination of HABP and HCQ could have dual antiresorptive and anabolic effects to prevent and treat osteoporosis.
Asunto(s)
Conservadores de la Densidad Ósea , Resorción Ósea , Difosfonatos , Hidroxicloroquina , Ovariectomía , Animales , Ovariectomía/efectos adversos , Femenino , Ratones , Hidroxicloroquina/farmacología , Hidroxicloroquina/uso terapéutico , Difosfonatos/farmacología , Difosfonatos/uso terapéutico , Resorción Ósea/prevención & control , Resorción Ósea/tratamiento farmacológico , Resorción Ósea/metabolismo , Conservadores de la Densidad Ósea/farmacología , Conservadores de la Densidad Ósea/uso terapéutico , Ratones Endogámicos C57BL , Anabolizantes/farmacología , Anabolizantes/uso terapéutico , Osteogénesis/efectos de los fármacos , Osteoporosis/tratamiento farmacológico , Osteoporosis/prevención & control , Osteoporosis/metabolismo , Osteoporosis/patología , Osteoclastos/efectos de los fármacos , Osteoclastos/metabolismoRESUMEN
The International Society of Bone Morphometry (ISBM) is dedicated to advancing research, education, and clinical practice for osteoporosis and other bone disorders by developing and improving tools for the quantitative imaging and analysis of bone. Its initial core mission was to promote the proper use of morphometric techniques in bone research and to educate and train clinicians and basic scientists in bone morphometry. This article chronicles the evolution of the ISBM and the history and development of bone morphometric techniques for the past 50-years, starting with workshops on bone morphometry in 1973, to the formal incorporation of the ISBM in 1996, to today. We also provide a framework and vision for the coming decades. This effort was led by ISBM presidents Dr Erica L. Scheller (2022-2024) and Dr Thomas J. Wronski (2009-2012) in collaboration with all other living ISBM presidents. Though the underlying techniques and questions have changed over time, the need for standardization of established tools and discovery of novel approaches for bone morphometry remains a constant. The ISBM fulfills this need by providing a forum for the exchange of ideas, with a philosophy that encourages the open discussion of pitfalls and challenges among clinicians, scientists, and industry partners. This facilitates the rapid development and adaptation of tools to meet emerging demands within the field of bone health at a high level.
RESUMEN
Fibrous dysplasia (FD) is a rare, disabling skeletal disease for which there are no established treatments. Growing evidence supports inhibiting the osteoclastogenic factor receptor activator of nuclear kappa-B ligand (RANKL) as a potential treatment strategy. In this study, we investigated the mechanisms underlying RANKL inhibition in FD tissue and its likely indirect effects on osteoprogenitors by evaluating human FD tissue pre- and post-treatment in a phase 2 clinical trial of denosumab (NCT03571191) and in murine in vivo and ex vivo preclinical models. Histological analysis of human and mouse tissue demonstrated increased osteogenic maturation, reduced cellularity, and reduced expression of the pathogenic Gαs variant in FD lesions after RANKL inhibition. RNA sequencing of human and mouse tissue supported these findings. The interaction between osteoclasts and mutant osteoprogenitors was further assessed in an ex vivo lesion model, which indicated that the proliferation of abnormal FD osteoprogenitors was dependent on osteoclasts. The results from this study demonstrated that, in addition to its expected antiosteoclastic effect, denosumab reduces FD lesion activity by decreasing FD cell proliferation and increasing osteogenic maturation, leading to increased bone formation within lesions. These findings highlight the unappreciated role of cellular crosstalk between osteoclasts and preosteoblasts/osteoblasts as a driver of FD pathology and demonstrate a novel mechanism of action of denosumab in the treatment of bone disease.TRIAL REGISTRATION: ClinicalTrials.gov NCT03571191.
Asunto(s)
Denosumab , Displasia Fibrosa Ósea , Animales , Humanos , Ratones , Denosumab/farmacología , Displasia Fibrosa Ósea/tratamiento farmacológico , Ligandos , Osteoblastos/metabolismo , Osteogénesis/genéticaRESUMEN
Enhanced and deficient immune responses are associated with abnormal bone homeostasis. A new study by Shinohara et al. (2008) shows that protein phosphorylation by the tyrosine kinases Bruton and Tec links immunity and bone as well as two signaling pathways in precursors of osteoclasts, the cells that degrade bone.
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Huesos/citología , Huesos/inmunología , Osteoblastos/metabolismo , Osteoclastos/metabolismo , Proteínas Tirosina Quinasas/metabolismo , Agammaglobulinemia Tirosina Quinasa , Animales , Huesos/enzimología , Diferenciación Celular , Humanos , Ratones , Osteoblastos/citología , Osteoblastos/enzimología , Osteoclastos/citología , Osteoclastos/enzimologíaRESUMEN
RelB and nuclear factor κB (NF-κB2) are the main effectors of NF-κB noncanonical signaling and play critical roles in many physiological processes. However, their role in hematopoietic stem/progenitor cell (HSPC) maintenance has not been characterized. To investigate this, we generated RelB/NF-κB2 double-knockout (dKO) mice and found that dKO HSPCs have profoundly impaired engraftment and self-renewal activity after transplantation into wild-type recipients. Transplantation of wild-type bone marrow cells into dKO mice to assess the role of the dKO microenvironment showed that wild-type HSPCs cycled more rapidly, were more abundant, and had developmental aberrancies: increased myeloid and decreased lymphoid lineages, similar to dKO HSPCs. Notably, when these wild-type cells were returned to normal hosts, these phenotypic changes were reversed, indicating a potent but transient phenotype conferred by the dKO microenvironment. However, dKO bone marrow stromal cell numbers were reduced, and bone-lining niche cells supported less HSPC expansion than controls. Furthermore, increased dKO HSPC proliferation was associated with impaired expression of niche adhesion molecules by bone-lining cells and increased inflammatory cytokine expression by bone marrow cells. Thus, RelB/NF-κB2 signaling positively and intrinsically regulates HSPC self-renewal and maintains stromal/osteoblastic niches and negatively and extrinsically regulates HSPC expansion and lineage commitment through the marrow microenvironment.
Asunto(s)
Microambiente Celular , Células Madre Hematopoyéticas/citología , FN-kappa B/metabolismo , Transducción de Señal , Animales , Células de la Médula Ósea/citología , Células de la Médula Ósea/efectos de los fármacos , Células de la Médula Ósea/metabolismo , Recuento de Células , Diferenciación Celular/efectos de los fármacos , Linaje de la Célula/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Tamaño de la Célula , Microambiente Celular/efectos de los fármacos , Citocinas/farmacología , Hematopoyesis/efectos de los fármacos , Células Madre Hematopoyéticas/efectos de los fármacos , Células Madre Hematopoyéticas/metabolismo , Mediadores de Inflamación/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Osteoblastos/citología , Osteoblastos/efectos de los fármacos , Osteoblastos/metabolismo , Transducción de Señal/efectos de los fármacos , Células del Estroma/citología , Células del Estroma/efectos de los fármacos , Células del Estroma/metabolismo , Factor de Transcripción ReIB/metabolismoRESUMEN
Maintenance of skeletal integrity requires the coordinated activity of multinucleated bone-resorbing osteoclasts and bone-forming osteoblasts. Osteoclasts form resorption lacunae on bone surfaces in response to cytokines by fusion of precursor cells. Osteoblasts are derived from mesenchymal precursors and lay down new bone in resorption lacunae during bone remodeling. Nuclear factorkappa B (NF-κB) signaling regulates osteoclast and osteoblast formation and is activated in osteoclast precursors in response to the essential osteoclastogenic cytokine, receptor activator of NF-κB ligand (RANKL), which can also control osteoblast formation through RANK-RANKL reverse signaling in osteoblast precursors. RANKL and some pro-inflammatory cytokines, including tumor necrosis factor (TNF), activate NF-κB signaling to positively regulate osteoclast formation and functions. However, these cytokines also limit osteoclast and osteoblast formation through NF-κB signaling molecules, including TNF receptor-associated factors (TRAFs). TRAF6 mediates RANKL-induced osteoclast formation through canonical NF-κB signaling. In contrast, TRAF3 limits RANKL- and TNF-induced osteoclast formation, and it restricts transforming growth factor ß (TGFß)-induced inhibition of osteoblast formation in young and adult mice. During aging, neutrophils expressing TGFß and C-C chemokine receptor type 5 (CCR5) increase in bone marrow of mice in response to increased NF-κB-induced CC motif chemokine ligand 5 (CCL5) expression by mesenchymal progenitor cells and injection of these neutrophils into young mice decreased bone mass. TGFß causes degradation of TRAF3, resulting in decreased glycogen synthase kinase-3ß/ß-catenin-mediated osteoblast formation and age-related osteoporosis in mice. The CCR5 inhibitor, maraviroc, prevented accumulation of TGFß+/CCR5+ neutrophils in bone marrow and increased bone mass by inhibiting bone resorption and increasing bone formation in aged mice. This paper updates current understanding of how NF-κB signaling is involved in the positive and negative regulation of cytokine-mediated osteoclast and osteoblast formation and activation with a focus on the role of TRAF3 signaling, which can be targeted therapeutically to enhance bone mass.