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1.
FASEB J ; 38(13): e23704, 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-38884155

RESUMEN

Inflammation plays a crucial role in the development of various disease conditions or is closely associated with them. Inflammatory cytokines like TNF often engage in interactions with other cytokines and growth factors, including TGFß, to orchestrate inflammatory process. Basal/endogenous TGFß signaling is a universal presence, yet the precise way TNF communicates with TGFß signaling to regulate inflammation and influence inflammatory levels in macrophages has remained elusive. To address this question, this study utilized genetic approaches and a combination of molecular and cellular methods, including conditional TGFß receptor knockout mice, human cells, RNAseq, ATACseq and Cut & Run-seq. The results reveal that the TGFß signaling functions as a vital homeostatic pathway, curtailing uncontrolled inflammation in macrophages in response to TNF. Conversely, TNF employs two previously unrecognized mechanisms to suppress the TGFß signaling. These mechanisms encompass epigenetic inhibition and RBP-J-mediated inhibition of the TGFß signaling pathway by TNF. These mechanisms empower TNF to diminish the antagonistic influence exerted by the TGFß signaling pathway, ultimately enhancing TNF's capacity to induce heightened levels of inflammation. This reciprocal suppression dynamic between TNF and the TGFß signaling pathway holds unique physiopathological significance, as it serves as a crucial "braking" mechanism. The balance between TNF levels and the activity of the endogenous TGFß signaling pathway plays a pivotal role in determining the overall extent of inflammation. The potential for therapeutically augmenting the TGFß signaling pathway presents an intriguing avenue for countering the impact of TNF and, consequently, developing innovative strategies for inflammation control.


Asunto(s)
Inflamación , Macrófagos , Ratones Noqueados , Transducción de Señal , Factor de Crecimiento Transformador beta , Factor de Necrosis Tumoral alfa , Animales , Factor de Crecimiento Transformador beta/metabolismo , Ratones , Macrófagos/metabolismo , Inflamación/metabolismo , Humanos , Factor de Necrosis Tumoral alfa/metabolismo , Ratones Endogámicos C57BL
2.
ACS Omega ; 9(2): 2795-2802, 2024 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-38250430

RESUMEN

There is a demand for the effective utilization of solar energy with highly functional photoelectrodes for photoelectrochemical (PEC) applications, such as water splitting and CO2 reduction. TiO2 nanotube arrays (TNTA) with a large surface area have been studied as potential photoelectrodes mainly due to their strong oxidation potential. However, it has disadvantages of fast charge recombination and little responsivity to visible light. In this study, we prepared TNTA by anodizing a Ti plate and decorated the TNTA with Al,Cr-codoped SrTiO3 (STO) nanocubes through a hydrothermal treatment to enhance the PEC properties. We also prepared pristine and undoped STO-decorated TNTA for comparison. The hydrothermal treatment duration was optimized for the TNTA-STO:Al,Cr sample to achieve the best PEC performance. Finally, the possible PEC reaction mechanism was proposed based on the obtained experimental results.

3.
J Phys Chem Lett ; 14(12): 3063-3068, 2023 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-36947156

RESUMEN

The impact of the vibrational coupling of the OH stretch mode on the spectra differs significantly between IR and Raman spectra of water. Unified understanding of the vibrational couplings is not yet achieved. By using a different class of vibrational spectroscopy, hyper-Raman (HR) spectroscopy, together with machine-learning-assisted HR spectra calculation, we examine the impact of the vibrational couplings of water through the comparison of isotopically diluted H2O and pure H2O. We found that the isotopic dilution reduces the HR bandwidths, but the impact of the vibrational coupling is smaller than in the IR and parallel-polarized Raman. Machine learning HR spectra indicate that the intermolecular coupling plays a major role in broadening the bandwidth, while the intramolecular coupling is negligibly small, which is consistent with the IR and Raman spectra. Our result clearly demonstrates a limited impact of the intramolecular vibration, independent of the selection rules of vibrational spectroscopies.

4.
Elife ; 122023 02 13.
Artículo en Inglés | MEDLINE | ID: mdl-36779851

RESUMEN

M-CSF is a critical growth factor for myeloid lineage cells, including monocytes, macrophages, and osteoclasts. Tissue-resident macrophages in most organs rely on local M-CSF. However, it is unclear what specific cells in the bone marrow produce M-CSF to maintain myeloid homeostasis. Here, we found that Adipoq-lineage progenitors but not mature adipocytes in bone marrow or in peripheral adipose tissue, are a major cellular source of M-CSF, with these Adipoq-lineage progenitors producing M-CSF at levels much higher than those produced by osteoblast lineage cells. The Adipoq-lineage progenitors with high CSF1 expression also exist in human bone marrow. Deficiency of M-CSF in bone marrow Adipoq-lineage progenitors drastically reduces the generation of bone marrow macrophages and osteoclasts, leading to severe osteopetrosis in mice. Furthermore, the osteoporosis in ovariectomized mice can be significantly alleviated by the absence of M-CSF in bone marrow Adipoq-lineage progenitors. Our findings identify bone marrow Adipoq-lineage progenitors as a major cellular source of M-CSF in bone marrow and reveal their crucial contribution to bone marrow macrophage development, osteoclastogenesis, bone homeostasis, and pathological bone loss.


Asunto(s)
Factor Estimulante de Colonias de Macrófagos , Osteogénesis , Ratones , Humanos , Animales , Factor Estimulante de Colonias de Macrófagos/metabolismo , Médula Ósea , Diferenciación Celular , Macrófagos/metabolismo , Osteoclastos/metabolismo , Células de la Médula Ósea/metabolismo , Ratones Endogámicos C57BL , Adiponectina/metabolismo
5.
Polymers (Basel) ; 15(1)2023 Jan 03.
Artículo en Inglés | MEDLINE | ID: mdl-36616587

RESUMEN

The ability of poly-ferric-silicate-sulphate (PFSS) synthesized via a co-polymerization process has been applied for the removal of diazo Congo red dye. A novel degradation pathway of diazo Congo red dye by using PFSS is proposed based on LC-MS analysis. Diazo Congo red dye was successfully removed using synthesized PFSS at lower coagulant dosages and a wider pH range, i.e., 9 mg/L from pH 5 to 7, 11 mg/L at pH 9, and 50 mg/L at pH 11. The azo bond cleavage was verified by the UV-Vis spectra of diazo Congo red-loaded PFSS and FTIR spectra which showed disappearance of the peak at 1584 cm-1 for -N=N- stretching vibrations. The synchronized results of UV-Vis spectra, FTIR, and the LC-MS analysis in this study confirmed the significance of the Si and Fe bond in PFSS towards the degradation of diazo Congo red dye. The successfully synthesized PFSS coagulant was characterized by FTIR, SEM, TEM, and HRTEM analysis. From this analysis, it was proven that PFSS is a polycrystalline material which is favorable for the coagulation-flocculation process. Based on all these findings, it was established that synthesized PFSS can be employed as a highly efficient polymeric coagulant for the removal of dye from wastewater.

6.
Sci Rep ; 13(1): 103, 2023 Jan 03.
Artículo en Inglés | MEDLINE | ID: mdl-36596849

RESUMEN

Anodic TiO2 nanotube arrays (TNTAs) have attracted much attention due to their excellent photoelectrochemical (PEC) properties. In this work, the tube length of TNTAs was optimized for efficient PEC water splitting under two different conditions, in which very few or a massive amount of gas bubbles were generated on the electrodes. As a result, relatively longer TNTAs were found to be preferable for higher PEC performance when a larger number of bubbles were generated. This suggests that the mass transport in the electrolyte is assisted by the generated bubbles, so that the electrode surfaces are more easily exposed to the fresh electrolyte, leading to the higher PEC performance.

7.
NMC Case Rep J ; 9: 243-247, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36128056

RESUMEN

Owing to recent advances in medical optical technology, a high-definition (4K) three-dimensional (3D) exoscope has been developed as an alternative tool to using conventional microscopes for microscopic surgery, and its efficacy for neurosurgery has been reported. We report a case who underwent simultaneous surgery aiming for en bloc resection of an anterior skull base malignancy with concurrent exoscopic transcranial and endoscopic endonasal approaches using a 4K 3D exoscope. The patient was a 76-year-old woman who underwent en bloc resection for an anterior skull base olfactory neuroblastoma 13 years ago. After confirming the recurrence of progressive olfactory neuroblastoma, tumor resection was again decided to be performed. As with the first procedure, surgery was performed in an en bloc manner, using both transcranial and endonasal approaches. Exoscope provided enough space above the surgical field to allow us to perform transcranial and endonasal surgeries simultaneously. Moreover, the surgeons could maintain a comfortable posture throughout the procedure, and total tumor removal was successfully achieved without any abnormal event. To our knowledge, this is the first report of the introduction of an exoscope aiming for en bloc resection of an anterior skull base malignancy while performing simultaneous surgery with both transcranial and endonasal approaches. We believe that the more cases are accumulated, the more efficacy of a 4K 3D exoscope will be elucidated.

8.
J Chem Phys ; 157(5): 054505, 2022 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-35933221

RESUMEN

Hyper-Raman (HR) spectra of benzene-h6, benzene-d6, and pyridine in the liquid phase excited at 1064 nm were measured by a picosecond laser with a high repetition rate. Although benzene and pyridine are important aromatic molecules, the qualities of the HR spectra previously reported were not high enough to be compared with those of IR and Raman spectroscopy. Our HR spectroscopic system significantly improves sensitivity that enables the detection of HR bands of benzene and pyridine not observed before. In addition to band assignments, we interpret HR bands of benzene based on the vibronic coupling theory of (pre-) resonance hyper-Raman scattering. Depolarization ratios of HR bands of benzene and pyridine, obtained from polarized-HR measurements, are first examined from a theoretical point of view of HR spectroscopy. Moreover, we evaluate quantum chemical calculations for HR spectra by comparing experimental and computational spectra. We show that the frequency-dependent polarizability and hyperpolarizability calculations using time-dependent density functional theory well reproduce the HR experiments for bulk aromatic compounds.

9.
Nat Commun ; 13(1): 3920, 2022 07 07.
Artículo en Inglés | MEDLINE | ID: mdl-35798734

RESUMEN

It is well-established that receptor activator of NF-κB ligand (RANKL) is the inducer of physiological osteoclast differentiation. However, the specific drivers and mechanisms driving inflammatory osteoclast differentiation under pathological conditions remain obscure. This is especially true given that inflammatory cytokines such as tumor necrosis factor (TNF) demonstrate little to no ability to directly drive osteoclast differentiation. Here, we found that transforming growth factor ß (TGFß) priming enables TNF to effectively induce osteoclastogenesis, independently of the canonical RANKL pathway. Lack of TGFß signaling in macrophages suppresses inflammatory, but not basal, osteoclastogenesis and bone resorption in vivo. Mechanistically, TGFß priming reprograms the macrophage response to TNF by remodeling chromatin accessibility and histone modifications, and enables TNF to induce a previously unrecognized non-canonical osteoclastogenic program, which includes suppression of the TNF-induced IRF1-IFNß-IFN-stimulated-gene axis, IRF8 degradation and B-Myb induction. These mechanisms are active in rheumatoid arthritis, in which TGFß level is elevated and correlates with osteoclast activity. Our findings identify a TGFß/TNF-driven inflammatory osteoclastogenic program, and may lead to development of selective treatments for inflammatory osteolysis.


Asunto(s)
Resorción Ósea , Osteogénesis , Resorción Ósea/metabolismo , Diferenciación Celular , Humanos , Macrófagos/metabolismo , FN-kappa B/metabolismo , Osteoclastos/metabolismo , Ligando RANK/metabolismo , Factor de Crecimiento Transformador beta/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo
10.
Lab Chip ; 22(15): 2801-2809, 2022 07 26.
Artículo en Inglés | MEDLINE | ID: mdl-35642562

RESUMEN

Here, we achieve shape-based separation of drug-treated Escherichia coli (E. coli) by viscoelastic microfluidics. Since shape is critical for modulating biological functions of E. coli, the ability to prepare homogeneous E. coli populations adopting uniform shape or sort bacterial sub-population based on their shape has significant implications for a broad range of biological, biomedical and environmental applications. A proportion of E. coli treated with 1 µg mL-1 of the antibiotic mecillinam were found to exhibit changes in shape from rod to sphere, and the heterogeneous E. coli populations after drug treatment with various aspect ratios (ARs) ranging from 1.0 to 5.5 were used for experiment. We demonstrate that E. coli with a lower AR, i.e., spherical E. coli (AR ≤ 1.5), are directed toward the middle outlet, while rod-shaped E. coli with a higher AR (AR > 1.5) are driven to the side outlets. Further, we demonstrate that the separation performance of the viscoelastic microfluidic device is influenced by two main factors: sheath-to-sample flow rate ratio and the concentration of poly-ethylene-oxide (PEO). To the best of our knowledge, this is the first report on shape-based separation of a single species of cells smaller than 4 µm by microfluidics.


Asunto(s)
Escherichia coli , Microfluídica , Humanos , Dispositivos Laboratorio en un Chip , Polietilenglicoles
11.
J Clin Invest ; 132(11)2022 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-35472067

RESUMEN

Rheumatoid arthritis (RA) is characterized by chronic synovial inflammation with aberrant epigenetic alterations, eventually leading to joint destruction. However, the epigenetic regulatory mechanisms underlying RA pathogenesis remain largely unknown. Here, we showed that ubiquitin-like containing PHD and RING finger domains 1 (UHRF1) is a central epigenetic regulator that orchestrates multiple pathogeneses in RA in a suppressive manner. UHRF1 expression was remarkably upregulated in synovial fibroblasts (SFs) from arthritis model mice and patients with RA. Mice with SF-specific Uhrf1 conditional knockout showed more severe arthritic phenotypes than littermate controls. Uhrf1-deficient SFs also exhibited enhanced apoptosis resistance and upregulated expression of several cytokines, including Ccl20. In patients with RA, DAS28, CRP, and Th17 accumulation and apoptosis resistance were negatively correlated with UHRF1 expression in synovium. Finally, Ryuvidine administration stabilized UHRF1 ameliorated arthritis pathogeneses in a mouse model of RA. This study demonstrated that UHRF1 expressed in RA SFs can contribute to negative feedback mechanisms that suppress multiple pathogenic events in arthritis, suggesting that targeting UHRF1 could be one of the therapeutic strategies for RA.


Asunto(s)
Artritis Reumatoide , Proteínas Potenciadoras de Unión a CCAAT , Epigénesis Genética , Ubiquitina-Proteína Ligasas , Animales , Artritis Reumatoide/patología , Proteínas Potenciadoras de Unión a CCAAT/genética , Proteínas Potenciadoras de Unión a CCAAT/metabolismo , Fibroblastos/metabolismo , Expresión Génica , Humanos , Inflamación/patología , Ratones , Membrana Sinovial/patología , Ubiquitina-Proteína Ligasas/genética , Ubiquitina-Proteína Ligasas/metabolismo
12.
J Mater Chem B ; 10(10): 1641-1649, 2022 03 09.
Artículo en Inglés | MEDLINE | ID: mdl-35194628

RESUMEN

Herein, we discuss a new pyrene-based push-pull dye (PC) and our investigation of its photophysical properties and applicability to biological studies. The newly synthesized dye exhibits highly polarity-sensitive fluorescence over a significantly wide range (i.e., the green to far-red region), accompanied by high fluorescence quantum yields (ΦFL > 0.70 in most organic solvents) and superior photostability to that of the commonly used Nile Red (NR) dye, which also fluoresces in the green to red region. When human prostate cancer cells stained with PC were imaged using a confocal laser scanning fluorescence microscope, PC was found to selectively stain the lipid droplets. Under the cell conditions where the formation of droplets was inhibited, PC could be distributed to both the remaining droplets and the intercellular membranes, which could be distinguished based on the fluorescence solvatochromic function of PC. Furthermore, PC efficiently stained normal human skin tissue blocks treated with a transparency-enhancing agent and enabled clear visualization of individual cells in each tissue architecture by means of two-photon fluorescence microscopy (2PM). Interestingly, PC provides bright 2PM images under tissue-penetrative 960 nm excitation, realizing much clearer and deeper tissue imaging than conventional pyrene dyes and NR. These results suggest that PC could replace several commonly used dyes in various biological applications, particularly the rapid and accurate diagnosis of tissue diseases, typified by biopsy.


Asunto(s)
Colorantes Fluorescentes , Pirenos , Piel , Células HeLa , Humanos , Gotas Lipídicas , Microscopía Fluorescente/métodos
13.
Biochem Biophys Res Commun ; 590: 132-138, 2022 01 29.
Artículo en Inglés | MEDLINE | ID: mdl-34974301

RESUMEN

Osteocytes are master regulators of skeletal homeostasis. However, little is known about the molecular mechanism of their differentiation. Epigenetic regulations, especially H3K27me3 modification, play critical roles in cell differentiation. Here, we found that H3K27me3 in the loci of osteocyte-expressing genes decreased during osteocyte differentiation and that H3K27me3 demethylase, Utx, was bound to the loci of those genes. To investigate the physiological functions of Utx in vivo, we generated late osteoblast-to-osteocyte specific Utx knockout mice using Dmp1-cre mice (UtxΔOcy/ΔOcy). Micro CT analyses showed that UtxΔOcy/ΔOcy displayed osteopenic phenotypes with lower bone volume and trabecular number, and greater trabecular separation. Bone histomorphometric analysis showed that bone mineralization and formation were significantly lower in UtxΔOcy/ΔOcy. Furthermore, Dmp1 expression and the number of osteocytes were significantly decreased in UtxΔOcy/ΔOcy. These results suggest that Utx in Dmp1-expressing osteoblast/osteocyte positively regulates osteoblast-to-osteocyte differentiation through H3K27me3 modifications in osteocyte genes. Our results provide new insight into the molecular mechanism of osteocyte differentiation.


Asunto(s)
Diferenciación Celular , Histona Demetilasas/metabolismo , Histonas/metabolismo , Lisina/metabolismo , Osteoblastos/citología , Osteocitos/citología , Animales , Secuencia de Bases , Enfermedades Óseas Metabólicas/genética , Hueso Esponjoso/diagnóstico por imagen , Hueso Esponjoso/patología , Recuento de Células , Diferenciación Celular/genética , Regulación hacia Abajo/genética , Epigenoma , Sitios Genéticos , Histona Demetilasas/deficiencia , Metilación , Ratones Endogámicos C57BL , Ratones Noqueados , Osteoblastos/metabolismo , Osteocitos/metabolismo , Fenotipo , Procesamiento Proteico-Postraduccional , Transcriptoma/genética
14.
Front Cell Dev Biol ; 9: 651161, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34222229

RESUMEN

Osteoclasts are specialized bone-resorbing cells that contribute to physiological bone development and remodeling in bone metabolism throughout life. Abnormal production and activation of osteoclasts lead to excessive bone resorption in pathological conditions, such as in osteoporosis and in arthritic diseases with bone destruction. Recent epigenetic studies have shed novel insight into the dogma of the regulation of gene expression. microRNAs belong to a category of epigenetic regulators, which post-transcriptionally regulate and silence target gene expression, and thereby control a variety of biological events. In this review, we discuss miRNA biogenesis, the mechanisms utilized by miRNAs, several miRNAs that play important roles in osteoclast differentiation, function, survival and osteoblast-to-osteoclast communication, and their translational potential and challenges in bone biology and skeletal diseases.

15.
Acta Crystallogr C Struct Chem ; 77(Pt 5): 197-201, 2021 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-33949334

RESUMEN

The molecular and crystal structure of 1H-1,2,4-triazolium perchlorate, C2H4N3+·ClO4-, was determined as detailed crystallographic data had not been available previously. The structure has monoclinic (P21/m) symmetry. It is of interest in the field of energetic compounds because nitrogen-rich azoles are the backbone of high-density energetic compounds, and salt-based energetic materials can exhibit preferential energy-release behaviour. The bond angles of the 1,2,4-triazolium cation in this study were similar to those of a cationic triazole ring reported previously and were different from those of the neutral triazole ring. This study contributes to the available data that can be used to analyse the relationship between the structures and properties of energetic materials.

16.
Aliment Pharmacol Ther ; 53(1): 94-102, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33159407

RESUMEN

BACKGROUND: Vonoprazan, a potassium-competitive acid blocker, is used for acid-related diseases. Occasionally, small white protrusions called "stardust" gastric mucosa have been detected in the stomachs of some patients taking vonoprazan. AIMS: To determine the incidence of, and risk factors for, stardust gastric mucosa potentially induced by vonoprazan METHODS: In this study, we enrolled 19 503 patients who underwent endoscopy at our hospital between 2016 and 2019. Using propensity score matching, we retrospectively compared patients who received and did not receive vonoprazan. The two groups were matched for age, sex, history of proton pump inhibitor use, and atrophic gastritis. RESULTS: After 1:1 propensity score matching, each group comprised 2516 patients. Stardust gastric mucosa was detected significantly more often in the stomachs of patients receiving vonoprazan than those who had not received vonoprazan (4.9% vs 0.2%, P < 0.001). Its location was 70.7% in the upper third of the stomach, 29.3% in the middle third and none in the lower third. Histologically, this lesion had a mucus pool within a dilated duct surrounded by flattened glandular epithelium. The cumulative incidence rate of stardust gastric mucosa at 1, 2 and 3 years was 4.6%, 16.5% and 26.2%, respectively. The factors independently associated with the presence of stardust gastric mucosa were >205 days of vonoprazan oral intake (odds ratio [OR]: 6.99, 95% confidence interval [CI]: 4.60-10.88) and female sex (OR: 1.75, 95% CI: 1.20-2.58). CONCLUSIONS: Stardust gastric mucosa appeared more frequently in the stomachs of patients taking vonoprazan.


Asunto(s)
Mucosa Gástrica , Pirroles , Femenino , Humanos , Incidencia , Puntaje de Propensión , Inhibidores de la Bomba de Protones/efectos adversos , Pirroles/efectos adversos , Estudios Retrospectivos , Factores de Riesgo , Sulfonamidas
17.
Dig Dis ; 39(4): 341-350, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33142288

RESUMEN

INTRODUCTION: Elobixibat is a new laxative, but its efficacy and adverse events (AEs) are insufficiently examined compared with those of other laxatives. Hence, by propensity score (PS) matching, we compared the effects and AEs between elobixibat and lubiprostone. METHODS: We retrospectively analyzed 1,887 Japanese patients with chronic constipation (CC) treated at our hospital between October 2013 and April 2020. Enrolled patients were divided into three treatment groups, namely, elobixibat (10 mg daily) (E10 group, n = 293), lubiprostone (24 µg daily) (L24 group, n = 772), and lubiprostone (48 µg daily) (L48 group, n = 822), as their first treatment. We then investigated the changes on the weekly average number of spontaneous bowel movements, stool consistency scores (SCSs), and AEs starting from the baseline until the end of the 2-week treatment. To adjust for patients' background, we performed one-to-one nearest neighbor matching without replacement between elobixibat- and lubiprostone-treated patients according to the individual estimated PSs. RESULTS: After treatment, for SCSs, both the L24 and L48 groups significantly improved compared with the E10 group (p < 0.05), but their stools were soft (Bristol Stool Form Scale: 4.8). Notably, the E10 group had less frequent AEs than the L24 group (26 [9.0%] vs. 43 [14.8%], p = 0.03). Particularly, nausea was significantly less in the E10 group than that in the L48 group (2 [0.7%] vs. 7 [2.4%], p = 0.01). CONCLUSION: Elobixibat is a beneficial drug for patients with mildly symptomatic CC and is safe to use, given its few AEs.


Asunto(s)
Estreñimiento/tratamiento farmacológico , Dipéptidos/uso terapéutico , Laxativos/uso terapéutico , Lubiprostona/uso terapéutico , Tiazepinas/uso terapéutico , Enfermedad Crónica , Defecación/efectos de los fármacos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Puntaje de Propensión , Estudios Retrospectivos , Resultado del Tratamiento
18.
Elife ; 92020 12 29.
Artículo en Inglés | MEDLINE | ID: mdl-33373293

RESUMEN

Bone remodeling involves a balance between bone resorption and formation. The mechanisms underlying bone remodeling are not well understood. DEF6 is recently identified as a novel loci associated with bone mineral density. However, it is unclear how Def6 impacts bone remodeling. We identify Def6 as a novel osteoblastic regulator that suppresses osteoblastogenesis and bone formation. Def6 deficiency enhances both bone resorption and osteogenesis. The enhanced bone resorption in Def6-/- mice dominates, leading to osteoporosis. Mechanistically, Def6 inhibits the differentiation of both osteoclasts and osteoblasts via a common mechanism through endogenous type-I IFN-mediated feedback inhibition. RNAseq analysis shows expression of a group of IFN stimulated genes (ISGs) during osteoblastogenesis. Furthermore, we found that Def6 is a key upstream regulator of IFNß and ISG expression in osteoblasts. Collectively, our results identify a novel immunoregulatory function of Def6 in bone remodeling, and shed insights into the interaction between immune system and bone.


Asunto(s)
Interferón gamma/fisiología , Osteoblastos/fisiología , Osteogénesis/fisiología , Animales , Regulación de la Expresión Génica , Factores Reguladores del Interferón/fisiología , Interferón gamma/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados
19.
Bone Res ; 8: 11, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32133214

RESUMEN

The axon guidance cue SLIT3 was identified as an osteoanabolic agent in two recent reports. However, these reports conflict in their nomination of osteoblasts versus osteoclasts as the key producers of skeletal SLIT3 and additionally offer conflicting data on the effects of SLIT3 on osteoclastogenesis. Here, aiming to address this discrepancy, we found no observable SLIT3 expression during human or mouse osteoclastogenesis and the only modest SLIT3-mediated effects on osteoclast differentiation. Conditional deletion of SLIT3 in cathepsin K (CTSK)-positive cells, including osteoclasts, had no effect on the number of osteoclast progenitors, in vitro osteoclast differentiation, overall bone mass, or bone resorption/formation parameters. Similar results were observed with the deletion of SLIT3 in LysM-positive cells, including osteoclast lineage cells. Consistent with this finding, bone marrow chimeras made from Slit3 -/- donors that lacked SLIT3 expression at all stages of osteoclast development displayed normal bone mass relative to controls. Taken in context, multiple lines of evidence were unable to identify the physiologic function of osteoclast-derived SLIT3, indicating that osteoblasts are the major source of skeletal SLIT3.

20.
FASEB J ; 34(2): 2392-2407, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31908034

RESUMEN

Bone resorption is a severe consequence of inflammatory diseases associated with osteolysis, such as rheumatoid arthritis (RA), often leading to disability in patients. In physiological conditions, the differentiation of bone-resorbing osteoclasts is delicately regulated by the balance between osteoclastogenic and anti-osteoclastogenic mechanisms. Inflammation has complex impact on osteoclastogenesis and bone destruction, and the underlying mechanisms of which, especially feedback inhibition, are underexplored. Here, we identify a novel regulatory network mediated by RBP-J/NFATc1-miR182 in TNF-induced osteoclastogenesis and inflammatory bone resorption. This network includes negative regulator RBP-J and positive regulators, NFATc1 and miR182, of osteoclast differentiation. In this network, miR182 is a direct target of both RBP-J and NFATc1. RBP-J represses, while NFATc1 activates miR182 expression through binding to specific open chromatin regions in the miR182 promoter. Inhibition of miR182 by RBP-J servers as a critical mechanism that limits TNF-induced osteoclast differentiation and inflammatory bone resorption. Inflammation, such as that which occurs in RA, shifts the expression levels of the components in this network mediated by RBP-J/NFATc1-miR182-FoxO3/PKR (previously identified miR182 targets) towards more osteoclastogenic, rather than healthy conditions. Treatment with TNF inhibitors in RA patients reverses the expression changes of the network components and osteoclastogenic potential. Thus, this network controls the balance between activating and repressive signals that determine the extent of osteoclastogenesis. These findings collectively highlight the biological significance and translational implication of this newly identified intrinsic regulatory network in inflammatory osteoclastogenesis and osteolysis.


Asunto(s)
Regulación de la Expresión Génica , Proteína de Unión a la Señal Recombinante J de las Inmunoglobulinas/metabolismo , MicroARNs/metabolismo , Factores de Transcripción NFATC/metabolismo , Osteoclastos/metabolismo , Osteólisis/metabolismo , Animales , Proteína de Unión a la Señal Recombinante J de las Inmunoglobulinas/genética , Inflamación/genética , Inflamación/metabolismo , Inflamación/patología , Ratones , Ratones Noqueados , MicroARNs/genética , Factores de Transcripción NFATC/genética , Osteoclastos/patología , Osteólisis/genética , Osteólisis/patología
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