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Bone homeostasis is maintained by an intricate balance between osteoclasts and osteoblasts, which becomes disturbed in osteoporosis. Metallothioneins (MTs) are major contributors in cellular zinc regulation. However, the role of MTs in bone cell regulation has remained unexplored. Single-cell RNA sequencing analysis discovered that, unlike the expression of other MT members, the expression of MT3 was unique to osteoclasts among various macrophage populations and was highly upregulated during osteoclast differentiation. This unique MT3 upregulation was validated experimentally and supported by ATAC sequencing data analyses. Downregulation of MT3 by gene knockdown or knockout resulted in excessive osteoclastogenesis and exacerbated bone loss in ovariectomy-induced osteoporosis. Transcriptome sequencing of MT3 knockdown osteoclasts and gene set enrichment analysis indicated that the oxidative stress and redox pathways were enriched, which was verified by MT3-dependent regulation of reactive oxygen species (ROS). In addition, MT3 deficiency increased the transcriptional activity of SP1 in a manner dependent on intracellular zinc levels. This MT3-zinc-SP1 axis was crucial for the control of osteoclasts, as zinc chelation and SP1 knockdown abrogated the promotion of SP1 activity and osteoclastogenesis by MT3 deletion. Moreover, SP1 bound to the NFATc1 promoter, and overexpression of an inactive SP1 mutant negated the effects of MT3 deletion on NFATc1 and osteoclastogenesis. In conclusion, MT3 plays a pivotal role in controlling osteoclastogenesis and bone metabolism via dual axes involving ROS and SP1. The present study demonstrated that MT3 elevation is a potential therapeutic strategy for osteolytic bone disorders, and it established for the first time that MT3 is a crucial bone mass regulator.
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Periodontitis (PD) is an inflammatory disease with alveolar bone destruction by osteoclasts (OCs). In PD, both inflammation and OC activation are significantly influenced by periodontal ligament fibroblasts (PDL-Fib). Yet, whether PDL-Fib has heterogeneity and whether distinct PDL-Fib subsets have specific functions have not been investigated. In this study, we discovered the complexity of PDL-Fib in PD, utilizing single-cell RNA sequencing data from human PD patients. We identified distinct subpopulations of PDL-Fib: one expressing interleukin-1 beta (IL-1ß) and another expressing the receptor activator of nuclear factor-kappa B ligand (RANKL), both crucial in OC differentiation and bone resorption. In periodontal tissues of mice with PD, active IL-1ß, cleaved caspase 1, and nucleotide-binding oligomerization domain-like receptor 3 (NLPR3) were significantly elevated, implicating the NLRP3 inflammasome in IL-1ß production. Upon stimulation of PDL-Fib with LPS from Porphyromonas gingivalis (pg), the most well-characterized periodontal bacteria, a more rapid increase in IL-1ß, followed by RANKL induction, was observed. IL-1ß and tumor necrosis factor alpha (TNF-α), another LPS-responsive cytokine, effectively increased RANKL in PDL-Fib, suggesting an indirect effect of pgLPS through IL-1ß and TNF-α on RANKL induction. Immunohistological analyses of mouse periodontal tissues also showed markedly elevated levels of IL-1ß and RANKL upon PD induction and displayed separate locations of IL-1ß-expressing PDL-Fib and RANKL-expressing PDL-Fib in PD. The heterogenic feature of fibroblasts expressing IL-1ß and RANKL was also mirrored in our combined cross-tissue single-cell RNA sequencing datasets analysis. In summary, our study elucidates the heterogeneity of PDL-Fib, highlighting distinct functional groups for producing RANKL and IL-1ß, which collectively promote OC generation and bone destruction in PD.
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Fibroblastos , Interleucina-1beta , Ligamento Periodontal , Periodontitis , Ligando RANK , Animales , Humanos , Masculino , Ratones , Fibroblastos/metabolismo , Perfilación de la Expresión Génica , Interleucina-1beta/metabolismo , Interleucina-1beta/genética , Ratones Endogámicos C57BL , Osteoclastos/metabolismo , Ligamento Periodontal/metabolismo , Ligamento Periodontal/citología , Ligamento Periodontal/patología , Periodontitis/metabolismo , Periodontitis/genética , Periodontitis/patología , Ligando RANK/metabolismo , Ligando RANK/genética , Análisis de Expresión Génica de una Sola CélulaRESUMEN
The oral colonization of periodontal pathogens onto gingival tissues establishes hypoxic microenvironment, often disrupting periodontal homeostasis in conjunction with oxidative stress. The association between reactive oxygen species (ROS) and osteolytic periodontitis have been suggested by recent studies. PTEN-induced kinase 1 (PINK1), a mitochondrial serine/threonine kinase, is an essential protein for mitochondrial quality control as it protects cells from oxidative stress by promoting degradation of damaged mitochondria through mitophagy. However, the pathophysiological roles of PINK1 in osteoclast-mediated bone loss have not been explored. Here we aimed to determine whether PINK1 plays a role in the regulation of osteoclastogenesis and alveolar bone resorption associated with periodontitis. C57BL/6 wild type (WT) and Pink1 knockout (KO) mice were subjected to ligature-induced periodontitis (LIP), and alveolar bones were evaluated by µCT-analysis and tartrate-resistant acid phosphatase (TRAP) staining. The µCT-analysis showed that bone volume fraction and travecular thickness were lower in Pink1 KO compared to WT mice. The number of TRAP-positive osteoclasts was markedly increased in the periodontal tissues of Pink1 KO mice with LIP. The genetic silencing or deletion of Pink1 promoted excessive osteoclast differentiation and bone resorption in vitro, as respectively indicated by TRAP staining and resorption pits on dentin slices. PINK1 deficiency led to mitochondrial instabilities as indicated by confocal microscopy of mitochondrial ROS, mitochondrial oxygen consumption rate (OCR) analysis, and transmission electron microscopy (TEM). Consequently, a significant increase in Ca2+-nuclear factor of activated T cells 1 (NFATc1) signaling was also found. On the other hand, restoration of mitophagy and autophagy by spermidine (SPD) treatment and the resolution of oxidative stress by N-acetyl-l-cysteine (NAC) treatment protected PINK1 deficiency-induced excessive generation of osteoclasts. Taken together, our findings demonstrate that PINK1 is essential for maintaining mitochondrial homeostasis during osteoclast differentiation. Therefore, targeting PINK1 may provide a novel therapeutic strategy for severe periodontitis with fulminant osteolysis.
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Pérdida de Hueso Alveolar , Periodontitis , Animales , Ratones , Pérdida de Hueso Alveolar/complicaciones , Pérdida de Hueso Alveolar/tratamiento farmacológico , Ratones Endogámicos C57BL , Mitofagia/genética , Osteoclastos/metabolismo , Periodontitis/genética , Proteínas Quinasas/genética , Proteínas Quinasas/metabolismo , Especies Reactivas de Oxígeno/metabolismoRESUMEN
Plasminogen activator inhibitor-1 (PAI-1) is associated with nonalcoholic fatty liver disease (NAFLD) by lipid accumulation in the liver. In this study, we showed that extracellular vesicles (EVs) from the periodontal pathogens Filifactor alocis and Porphyromonas gingivalis induced steatosis by inducing PAI-1 in the liver and serum of mice fed a low-fat diet. PAI-1 induction was not observed in TLR2-/- mice. When tested using HEK-Blue hTLR2 cells, human TLR2 reporter cells, the TLR2-activating ability of serum from NAFLD patients (n = 100) was significantly higher than that of serum from healthy subjects (n = 100). Correlation analysis confirmed that PAI-1 levels were positively correlated with the TLR2-activating ability of serum from NAFLD patients and healthy subjects. Amphiphilic molecules in EVs were involved in PAI-1 induction. Our data demonstrate that the TLR2/PAI-1 axis is important for hepatic steatosis by EVs of periodontal pathogens.
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Vesículas Extracelulares , Enfermedad del Hígado Graso no Alcohólico , Inhibidor 1 de Activador Plasminogénico , Receptor Toll-Like 2 , Animales , Humanos , RatonesRESUMEN
Osteoclast generation from monocyte/macrophage lineage precursor cells needs to be tightly regulated to maintain bone homeostasis and is frequently over-activated in inflammatory conditions. PARK2, a protein associated with Parkinson's disease, plays an important role in mitophagy via its ubiquitin ligase function. In this study, we investigated whether PARK2 is involved in osteoclastogenesis. PARK2 expression was found to be increased during the receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast differentiation. PARK2 gene silencing with siRNA significantly reduced osteoclastogenesis induced by RANKL, LPS (lipopolysaccharide), TNFα (tumor necrosis factor α), and IL-1ß (interleukin-1ß). On the other hand, overexpression of PARK2 promoted osteoclastogenesis. This regulation of osteoclastogenesis by PARK2 was mediated by IKK (inhibitory κB kinase) and NF-κB activation while MAPK (mitogen-activated protein kinases) activation was not involved. Additionally, administration of PARK2 siRNA significantly reduced osteoclastogenesis and bone loss in an in vivo model of inflammatory bone erosion. Taken together, this study establishes a novel role for PARK2 as a positive regulator in osteoclast differentiation and inflammatory bone destruction.
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Resorción Ósea , Ligando RANK , Humanos , Resorción Ósea/metabolismo , Diferenciación Celular , Interleucina-1beta/metabolismo , Ligasas/metabolismo , Lipopolisacáridos/farmacología , Proteínas Quinasas Activadas por Mitógenos/metabolismo , FN-kappa B/metabolismo , Osteoclastos , Osteogénesis/genética , Ligando RANK/metabolismo , ARN Interferente Pequeño/genética , ARN Interferente Pequeño/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Ubiquitinas/metabolismoRESUMEN
Dysbiosis of the oral microbiota plays an important role in the progression of periodontitis, which is characterized by chronic inflammation and alveolar bone loss, and associated with systemic diseases. Bacterial extracellular vesicles (EVs) contain various bioactive molecules and show diverse effects on host environments depending on the bacterial species. Recently, we reported that EVs derived from Filifactor alocis, a Gram-positive periodontal pathogen, had osteoclastogenic activity. In the present study, we analysed the osteoclastogenic potency and immunostimulatory activity of EVs derived from the Gram-negative periodontal pathogens Porphyromonas gingivalis and Tannerella forsythia, the oral commensal bacterium Streptococcus oralis, and the gut probiotic strain Lactobacillus reuteri. Bacterial EVs were purified by density gradient ultracentrifugation using OptiPrep (iodixanol) reagent. EVs from P. gingivalis, T. forsythia, and S. oralis increased osteoclast differentiation and osteoclstogenic cytokine expression in osteoclast precursors, whereas EVs from L. reuteri did not. EVs from P. gingivalis, T. forsythia, and S. oralis preferentially activated Toll-like receptor 2 (TLR2) rather than TLR4 or TLR9, and induced osteoclastogenesis mainly through TLR2. The osteoclastogenic effects of EVs from P. gingivalis and T. forsythia were reduced by both lipoprotein lipase and polymyxin B, an inhibitor of lipopolysaccharide (LPS), while the osteoclastogenic effects of EVs from S. oralis were reduced by lipoprotein lipase alone. These results demonstrate that EVs from periodontal pathogens and oral commensal have osteoclastogenic activity through TLR2 activation by lipoproteins and/or LPS.
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Vesículas Extracelulares , Boca , Osteoclastos , Diferenciación Celular , Vesículas Extracelulares/metabolismo , Lipopolisacáridos , Lipoproteína Lipasa , Microbiota , Boca/microbiología , Osteoclastos/metabolismo , Porphyromonas gingivalis/fisiología , Receptor Toll-Like 2 , Receptor Toll-Like 4RESUMEN
The widely used ZnO quantum dots (QDs) as an electron transport layer (ETL) in quantum dot light-emitting diodes (QLEDs) have one drawback. That the balancing of electrons and holes has not been effectively exploited due to the low hole blocking potential difference between the valence band (VB) (6.38 eV) of ZnO ETL and (6.3 eV) of CdSe/ZnS QDs. In this study, ZnO QDs chemically reacted with capping ligands of oleic acid (OA) to decrease the work function of 3.15 eV for ZnO QDs to 2.72~3.08 eV for the ZnO-OA QDs due to the charge transfer from ZnO to OA ligands and improve the efficiency for hole blocking as the VB was increased up to 7.22~7.23 eV. Compared to the QLEDs with a single ZnO QDs ETL, the ZnO-OA/ZnO QDs double ETLs optimize the energy level alignment between ZnO QDs and CdSe/ZnS QDs but also make the surface roughness of ZnO QDs smoother. The optimized glass/ITO/PEDOT:PSS/PVK//CdSe/ZnS//ZnO-OA/ZnO/Ag QLEDs enhances the maximum luminance by 5~9% and current efficiency by 16~35% over the QLEDs with a single ZnO QDs ETL, which can be explained in terms of trap-charge limited current (TCLC) and the Fowler-Nordheim (F-N) tunneling conduction mechanism.
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A facile thin film encapsulation (TFE) method having a triple-layered structure of a-SiN x :H/SiO x N y /hybrid SiO x (ASH) on QD-LEDs was performed utilizing both reproducible plasma-enhanced chemical vapor deposition (PECVD) and simple dip-coating processes without adopting atomic layer deposition (ALD). The ASH films fabricated on a polyethylene terephthalate (PET) substrate show a high average transmittance of 88.80% in the spectral range of 400-700 nm and a water vapor transmission rate (WVTR) value of 7.3 × 10-4 g per m2 per day. The measured time to reach 50% of the initial luminance (T50) at initial luminance values of 500, 1000, and 2000 cd m-2 was 711.6, 287.7, and 78.6 h, respectively, and the extrapolated T50 at 100 cd m-2 is estimated to be approximately 9804 h, which is comparable to that of the 12 112 h for glass lid-encapsulated QD-LEDs. This result demonstrates that TFE with the ASH films has the potential to overcome the conventional drawbacks of glass lid encapsulation.
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The ubiquitin proteasome system (UPS) is a protein degradation machinery that is crucial for cellular homeostasis in eukaryotes. Therefore, it is not surprising that the UPS coordinates almost all host cellular processes, including host-pathogen interactions. This protein degradation machinery acts predominantly by tagging substrate proteins designated for degradation with a ubiquitin molecule. These ubiquitin tags have been involved at various steps of the innate immune response. Hence, herpesviruses have evolved ways to antagonize the host defense mechanisms by targeting UPS components such as ubiquitin E3 ligases and deubiquitinases (DUBs) that establish a productive infection. This review delineates how herpesviruses usurp the critical roles of ubiquitin E3 ligases and DUBs in innate immune response to escape host-antiviral immune response, with particular focus on retinoic acid-inducible gene I (RIG-I)-like receptors (RLR), cyclic-GMP-AMP (cGAMP) synthase (cGAS), stimulator of interferon (IFN) genes (STING) pathways, and inflammasome signaling.
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Herpesviridae/inmunología , Inmunidad Innata , Transducción de Señal , Ubiquitina/metabolismo , Animales , Humanos , Factores Inmunológicos/metabolismo , Inflamación/patologíaRESUMEN
The differentiation and activity of bone-resorbing osteoclasts are tightly regulated to maintain the homeostasis of healthy bones. In this study, the role of protein tyrosine phosphatase 1B (PTP1B) during osteoclastogenesis was studied in myeloid-specific Ptpn1-deficient (conditional knockout [cKO]) mice. The mRNA and protein expression of PTP1B increased during the formation of mature osteoclasts from mouse bone macrophages on stimulation with macrophage-colony stimulating factor (M-CSF) and receptor activator of nuclear factor κB ligand (RANKL). The Ptpn1 cKO mice exhibited increased femoral trabecular bone volume with a decreased number and activity of osteoclasts compared with control mice. The in vitro culture of osteoclast precursors corroborated the inhibition of osteoclastogenesis in cKO cells compared with control, with concomitantly decreased RANKL-dependent proliferation, lower osteoclast marker gene expression, reduced nuclear expression of nuclear factor of activated T cells cytoplasmic 1 (NFATc1), diminished intracellular Ca2+ oscillations, and increased phosphorylation of proto-oncogene tyrosine-protein kinase Src on inhibitory tyrosine residue. In a ligature-induced periodontitis model, Ptpn1 cKO mice exhibited attenuated osteoclastogenesis and alveolar bone loss following the induction of inflammation. The Ptpn1-deficient mice were similarly protected from ovariectomy-induced bone loss compared with control mice. These results provide a novel regulatory role of PTP1B in osteoclastogenesis and suggest a potential as a therapeutic target for bone-lytic diseases. © 2021 American Society for Bone and Mineral Research (ASBMR).
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Resorción Ósea , Osteogénesis , Proteína Tirosina Fosfatasa no Receptora Tipo 1/metabolismo , Animales , Resorción Ósea/metabolismo , Diferenciación Celular , Femenino , Inflamación/metabolismo , Ratones , Ratones Endogámicos C57BL , Factores de Transcripción NFATC/metabolismo , Osteoclastos/metabolismo , Ovariectomía , Monoéster Fosfórico Hidrolasas/metabolismo , Ligando RANK/metabolismo , Tirosina/metabolismoRESUMEN
Transition metal dichalcogenide (TMD) nanosheets exfoliated in the liquid phase are of significant interest owing to their potential for scalable and flexible photoelectronic applications. Although various dispersants such as surfactants, oligomers, and polymers are used to obtain highly exfoliated TMD nanosheets, most of them are electrically insulating and need to be removed; otherwise, the photoelectric properties of the TMD nanosheets degrade. Here, inorganic halide perovskite nanocrystals (NCs) of CsPbX3 (X = Cl, Br, or I) are presented as non-destructive dispersants capable of dispersing TMD nanosheets in the liquid phase and enhancing the photodetection properties of the nanosheets, thus eliminating the need to remove the dispersant. MoSe2 nanosheets dispersed in the liquid phase are adsorbed with CsPbCl3 NCs. The CsPbCl3 nanocrystals on MoSe2 efficiently withdraw electrons from the nanosheets, and suppress the dark current of the MoSe2 nanosheets, leading to flexible near-infrared MoSe2 photodetectors with a high ON/OFF photocurrent ratio and detectivity. Moreover, lanthanide ion-doped CsPbCl3 NCs enhance the ON/OFF current ratio to >106 . Meanwhile, the dispersion stability of the MoSe2 nanosheets exfoliated with the perovskite NCs is sufficiently high.
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BACKGROUND: Protein methylation has important role in regulating diverse cellular responses, including differentiation, by affecting protein activity, stability, and interactions. AZ505 is an inhibitor of the SET and MYND domain-containing protein 2 lysine methylase. In this study, we investigated the effect of AZ505 on osteoblast and osteoclast differentiation in vitro and evaluated the effect of AZ505 in vivo on the long bones in mice. METHODS: Osteoblast differentiation was assessed by alkaline phosphatase (ALP) and Alizarin red staining after culturing calvarial preosteoblasts in an osteogenic medium. Osteoclast differentiation was analyzed by tartrate-resistant acid phosphatase (TRAP) staining in bone marrow-derived macrophages cultured with macrophage-colony stimulating factor and receptor activator of nuclear factor-κB ligand (RANKL). For in vivo experiments, mice were intraperitoneally injected with AZ505 and femurs were examined by micro-computed tomography. RESULTS: AZ505 increased ALP and Alizarin red staining in cultured osteoblasts and the expression of osteoblast marker genes, including Runx2 and osteocalcin. AZ505 resulted in decreased TRAP-staining of osteoclasts and expression of c-Fos and nuclear factor of activated T cells transcription factors and osteoclast marker genes, including cathepsin K and dendritic cell-specific transmembrane protein. Unexpectedly, in vivo administration of AZ505 markedly decreased the trabecular bone mass of femurs. In support of this catabolic result, AZ505 strongly upregulated RANKL expression in osteoblasts. CONCLUSIONS: The results indicate that AZ505 has a catabolic effect on bone metabolism in vivo despite its anabolic effect in bone cell cultures. The findings indicate that cell culture data should be extrapolated cautiously to in vivo outcomes for studying bone metabolism.
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Sjögren's syndrome (SS) is an autoimmune disease characterized by dryness of the mouth and eyes. The glandular dysfunction in SS involves not only T cell-mediated destruction of the glands but also autoantibodies against the type 3 muscarinic acetylcholine receptor or aquaporin 5 (AQP5) that interfere with the secretion process. Studies on the breakage of tolerance and induction of autoantibodies to these autoantigens could benefit SS patients. To break tolerance, we utilized a PmE-L peptide derived from the AQP5-homologous aquaporin of Prevotella melaninogenica (PmAqp) that contained both a B cell "E" epitope and a T cell epitope. Repeated subcutaneous immunization of C57BL/6 mice with the PmE-L peptide efficiently induced the production of Abs against the "E" epitope of mouse/human AQP5 (AQP5E), and we aimed to characterize the antigen specificity, the sequences of AQP5E-specific B cell receptors, and salivary gland phenotypes of these mice. Sera containing anti-AQP5E IgG not only stained mouse Aqp5 expressed in the submandibular glands but also detected PmApq and PmE-L by immunoblotting, suggesting molecular mimicry. Characterization of the AQP5E-specific autoantibodies selected from the screening of phage display Ab libraries and mapping of the B cell receptor repertoires revealed that the AQP5E-specific B cells acquired the ability to bind to the Ag through cumulative somatic hypermutation. Importantly, animals with anti-AQP5E Abs had decreased salivary flow rates without immune cell infiltration into the salivary glands. This model will be useful for investigating the role of anti-AQP5 autoantibodies in glandular dysfunction in SS and testing new therapeutics targeting autoantibody production.
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Periodontitis is an inflammatory disease induced by local infection in tooth-supporting tissue. Periodontitis is associated with systemic bone diseases, but little is known about the mechanism of the causal effect of periodontitis on systemic bone resorption. Bacteria-derived extracellular vesicles (EVs) act as natural carriers of virulence factors that are responsible for systemic inflammation. In this study, we investigated the role of EVs derived from Filifactor alocis, a Gram-positive, anaerobic periodontal pathogen, in systemic bone loss and osteoclast differentiation. F. alocis EVs accumulated in the long bones of mice after intraperitoneal administration. These EVs induced proinflammatory cytokines, osteoclastogenesis, and bone resorption via Toll-like receptor 2 (TLR2). The phase separation of F. alocis EVs showed that amphiphilic molecules were responsible for the induced bone resorption and osteoclastogenesis. The osteoclastogenic effects of F. alocis EVs were reduced by lipoprotein lipase. Proteomic analysis of the amphiphilic molecules identified seven lipoproteins. Our results indicate that lipoprotein-like molecules in F. alocis EVs may contribute to systemic bone loss via TLR2.
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Enfermedades Óseas/microbiología , Vesículas Extracelulares/metabolismo , Periodontitis/microbiología , Receptor Toll-Like 2/metabolismo , Animales , Clostridiales , Humanos , RatonesRESUMEN
BACKGROUND: Prostate cancers frequently metastasize to bone, where the best microenvironment for distant colonization is provided. Since osteotropic metastasis of prostate cancer is a critical determinant of patients' survival, searches for preventive measures are ongoing in the field. Therefore, it is important to dissect the mechanisms of each step of bone metastasis, including the epithelial-mesenchymal transition (EMT) and cross-talk between metastatic niches and cancer cells. METHODS: In this study, we established a highly bone-metastatic subline of human prostate cancer cells by selecting bone-homing population of PC3 cells after cardiac injection of eight-week-old male BALB/c-nude mice. Then we assessed the proliferation, EMT characteristics, and migration properties of the subline (mtPC3) cells in comparison with the parental PC3 cells. To investigate the role of S100A4, we performed gene knock-down by lentiviral transduction, or treated cells with recombinant S100A4 protein or a S100A4-neutralizing antibody. The effect of cancer cells on osteoclastogenesis was evaluated after treatment of pre-osteoclasts with conditioned medium (CM) from cancer cells. RESULTS: The mtPC3 cells secreted a markedly high level of S100A4 protein and showed elevated cell proliferation and mesenchymal properties. The increased proliferation and EMT traits of mtPC3 cells was inhibited by S100A4 knock-down, but was not affected by exogenous S100A4. Furthermore, S100A4 released from mtPC3 cells stimulated osteoclast development via the cell surface receptor RAGE. Down-regulation or neutralization of S100A4 in the CM of mtPC3 cells attenuated cancer-induced osteoclastogenesis. CONCLUSION: Altogether, our results suggest that intracellular S100A4 promotes cell proliferation and EMT characteristics in tumor cells, and that secreted S100A4 activates osteoclastogenesis, contributing to osteolytic bone metastasis. Thus, S100A4 upregulation in cancer cells highly metastatic to bone might be a key element in regulating bone metastasis.
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Neoplasias Óseas/secundario , Proliferación Celular , Transición Epitelial-Mesenquimal , Neoplasias de la Próstata/metabolismo , Neoplasias de la Próstata/patología , Proteína de Unión al Calcio S100A4/metabolismo , Animales , Comunicación Celular , Diferenciación Celular , Movimiento Celular , Medios de Cultivo Condicionados/farmacología , Regulación hacia Abajo , Femenino , Humanos , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos ICR , Ratones Desnudos , Osteoclastos/citología , Osteoclastos/efectos de los fármacos , Osteogénesis/efectos de los fármacos , Células PC-3 , Proteína de Unión al Calcio S100A4/genética , Regulación hacia ArribaRESUMEN
Osteoporosis is a disease in which bone mineral density decreases due to abnormal activity of osteoclasts, and is commonly found in post-menopausal women who have decreased levels of female hormones. Sphingosylphosphorylcholine (SPC) is an important biological lipid that can be converted to sphingosine-1-phosphate (S1P) by autotaxin. S1P is known to be involved in osteoclast activation by stimulating osteoblasts, but bone regulation by SPC is not well understood. In this study, we found that SPC strongly inhibits RANKL-induced osteoclast differentiation. SPC-induced inhibitory effects on osteoclast differentiation were not affected by several antagonists of S1P receptors or pertussis toxin, suggesting cell surface receptor independency. However, SPC inhibited RANKL-induced calcineurin activation and subsequent NFATc1 activity, leading to decrease of the expression of Trap and Ctsk. Moreover, we found that bone loss in an experimental osteoporosis mouse model was recovered by SPC injection. SPC also blocked ovariectomy-induced body weight increase and Nfatc1 gene expression in mice. We also found that SPC inhibits RANKL-induced osteoclast differentiation in human macrophages. Since currently available treatments for osteoporosis, such as administration of female hormones or hormone receptor modulators, show serious side effects, SPC has potential as a new agent for osteoporosis treatment.
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Calcio/metabolismo , Calmodulina/metabolismo , Osteoclastos/metabolismo , Osteoporosis/metabolismo , Ovariectomía/efectos adversos , Fosforilcolina/análogos & derivados , Esfingosina/análogos & derivados , Animales , Western Blotting , Resorción Ósea/tratamiento farmacológico , Resorción Ósea/metabolismo , Supervivencia Celular/efectos de los fármacos , Femenino , Ratones , Ratones Endogámicos C57BL , Osteoclastos/efectos de los fármacos , Osteoporosis/tratamiento farmacológico , Fosforilcolina/uso terapéutico , Reacción en Cadena en Tiempo Real de la Polimerasa , Esfingosina/uso terapéutico , Microtomografía por Rayos XRESUMEN
Filifactor alocis, an asaccharolytic anaerobic Gram-positive rod (AAGPR), is an emerging marker of periodontitis. Severe periodontitis causes destruction of the alveolar bone that supports teeth and can even lead to tooth loss. Based on our previous report that F. alocis-derived extracellular vesicles (FA EVs) contain various effector molecules and have immunostimulatory activity, we investigated the effect of FA EVs on osteogenesis using mouse bone-derived mesenchymal stromal cells (BMSCs). FA EVs dramatically inhibited bone mineralization similar to whole bacteria and reduced the expression levels of osteogenic marker genes. The osteogenic differentiation of TLR2-deficient BMSCs was not inhibited by FA EVs, suggesting that their inhibitory effect on osteogenesis is dependent on TLR2 signaling. FA EVs effectively activated TLR2 downstream signaling of the MAPK and NF-κB pathways. In addition, FA EVs regulated RANKL and OPG gene expression, increasing the RANKL/OPG ratio in BMSCs in a TLR2-dependent manner. Our study suggests that F. alocis-derived EVs interfere with bone metabolism via TLR2 activation, providing insight into the pathogenesis of bone loss associated with periodontitis.
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Clostridiales , Vesículas Extracelulares , Células Madre Mesenquimatosas/citología , Osteogénesis , Receptor Toll-Like 2/metabolismo , Animales , Diferenciación Celular , Ratones , Transducción de SeñalRESUMEN
Halide vacancy defect is one of the major origins of non-radiative recombination in the lead halide perovskite light emitting devices (LEDs). Hence the defect passivation is highly demanded for the high-performance perovskite LEDs. Here, we demonstrated that FA doping led to the enrichment of Br in Cs1-xFAxPbBr3 QDs. Due to the defect passivation by the enriched Br, the trap density in Cs1-xFAxPbBr3 significantly decreased after FA doping, and which improved the optical properties of Cs1-xFAxPbBr3 QDs and their QD-LEDs. PLQY of Cs1-xFAxPbBr3 QDs increased from 76.8% (x = 0) to 85.1% (x = 0.04), and Lmax and CEmax of Cs1-xFAxPbBr3 QD-LEDs were improved from Lmax = 2880 cd m-2 and CEmax = 1.98 cd A-1 (x = 0) to Lmax = 5200 cd m-2 and CEmax = 3.87 cd A-1 (x = 0.04). Cs1-xFAxPbBr3 QD-LED device structure was optimized by using PVK as a HTL and ZnO modified with b-PEI as an ETL. The energy band diagram of Cs1-xFAxPbBr3 QD-LEDs deduced by UPS analyses.
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Osteoclasts (OCs), cells specialized for bone resorption, are generated from monocyte/macrophage precursors by a differentiation process governed by RANKL. Here, we show that DCTN1, a key component of the dynactin complex, plays important roles in OC differentiation. The expression of DCTN1 was upregulated by RANKL. The inhibition of DCTN1 expression by gene knockdown suppressed OC formation, bone resorption, and the induction of NFATc1 and c-Fos, critical transcription factors for osteoclastogenesis. More importantly, the activation of Cdc42 by RANKL was inhibited upon DCTN1 silencing. The forced expression of constitutively active Cdc42 restored the OC differentiation of precursors with DCTN1 deletion. In addition, PAK2 was found to be activated by RANKL and to function downstream of Cdc42. The DCTN1-Cdc42 axis also inhibited apoptosis and caspase-3 activation. Furthermore, the anti-osteoclastogenic effect of DCTN1 knockdown was verified in an animal model of bone erosion. Intriguingly, DCTN1 overexpression was also detrimental to OC differentiation, suggesting that DCTN1 should be regulated at the appropriate level for effective osteoclastogenesis. Collectively, our results reveal that DCTN1 participates in the activation of Cdc42/PAK2 signaling and the inhibition of apoptosis during osteoclastogenesis.
Asunto(s)
Complejo Dinactina/metabolismo , Osteoclastos/metabolismo , Osteogénesis/fisiología , Transducción de Señal/fisiología , Proteína de Unión al GTP cdc42/metabolismo , Quinasas p21 Activadas/metabolismo , Animales , Apoptosis/fisiología , Resorción Ósea/metabolismo , Caspasa 3/metabolismo , Diferenciación Celular/fisiología , Modelos Animales de Enfermedad , Femenino , Macrófagos/metabolismo , Macrófagos/fisiología , Ratones , Ratones Endogámicos ICR , Factores de Transcripción NFATC/metabolismo , Osteoclastos/fisiología , Proteínas Proto-Oncogénicas c-fos/metabolismo , Ligando RANK/metabolismo , Regulación hacia Arriba/fisiologíaRESUMEN
Despite the great interest in inorganic halide perovskites (IHPs) for a variety of photoelectronic applications, environmentally robust nanopatterns of IHPs have hardly been developed mainly owing to the uncontrollable rapid crystallization or temperature and humidity sensitive polymorphs. Herein, we present a facile route for fabricating environment- and phase-stable IHP nanopatterns over large areas. Our method is based on nanoimprinting of a soft and moldable IHP adduct. A small amount of poly(ethylene oxide) was added to an IHP precursor solution to fabricate a spin-coated film that is soft and moldable in an amorphous adduct state. Subsequently, a topographically prepatterned elastomeric mold was used to nanoimprint the film to develop well-defined IHP nanopatterns of CsPbBr3 and CsPbI3 of 200 nm in width over a large area. To ensure environment- and phase-stable black CsPbI3 nanopatterns, a polymer backfilling process was employed on a nanopatterned CsPbI3. The CsPbI3 nanopatterns were overcoated with a thin poly(vinylidene fluoride-co-trifluoroethylene) (PVDF-TrFE) film, followed by thermal melting of PVDF-TrFE, which formed the air-exposed CsPbI3 nanopatterns laterally confined with PVDF-TrFE. Our polymer backfilled CsPbI3 nanopatterns exhibited excellent environmental stability over one year at ambient conditions and for 10 h at 85 °C, allowing the development of arrays of two-terminal, parallel-type photodetectors with nanopatterned photoactive CsPbI3 channels. Our polymer-assisted nanoimprinting offers a fast, low-pressure/temperature patterning method for high-quality nanopatterns on various substrates over a large area, overcoming conventional costly time-consuming lithographic techniques.