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Bone Jun 2024The effects of gender affirming hormone therapy (GAHT) on bone microarchitecture and fracture risk in adult transgender women is unclear. To investigate the concept that...
The effects of gender affirming hormone therapy (GAHT) on bone microarchitecture and fracture risk in adult transgender women is unclear. To investigate the concept that skeletal integrity and strength in trans women may be improved by treatment with a higher dose of GAHT than commonly prescribed, we treated adult male mice with a sustained, high dose of estradiol. Adult male mice at 16 weeks of age were administered ~1.3 mg estradiol by silastic implant, implanted intraperitoneally, for 12 weeks. Controls included vehicle treated intact females and males. High-dose estradiol treatment in males stimulated the endocortical deposition of bone at the femoral mid-diaphysis, increasing cortical thickness and bone area. This led to higher stiffness, maximum force, and the work required to fracture the bone compared to male controls, while post-yield displacement was unaffected. Assessment of the material properties of the bone showed an increase in both elastic modulus and ultimate stress in the estradiol treated males. Treatment of male mice with high dose estradiol was also anabolic for trabecular bone, markedly increasing trabecular bone volume, number and thickness in the distal metaphysis which was accompanied by an increase in the histomorphometric markers of bone remodelling, mineralizing surface/bone surface, bone formation rate and osteoclast number. In conclusion, a high dose of estradiol is anabolic for cortical and trabecular bone in a male to female transgender mouse model, increasing both stiffness and strength. These findings suggest that increasing the current dose of GAHT administered to trans women, while considering other potential adverse effects, may be beneficial to preserving their bone microstructure and strength.
PubMed: 38866125
DOI: 10.1016/j.bone.2024.117143 -
Cell Communication and Signaling : CCS Jun 2024Bone resorption is driven through osteoclast differentiation by macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor kappa-Β ligand...
Bone resorption is driven through osteoclast differentiation by macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor kappa-Β ligand (RANKL). We noted that a disintegrin and metalloproteinase (ADAM) 10 and ADAM17 are downregulated at the expression level during osteoclast differentiation of the murine monocytic cell line RAW264.7 in response to RANKL. Both proteinases are well known to shed a variety of single-pass transmembrane molecules from the cell surface. We further showed that inhibitors of ADAM10 or ADAM17 promote osteoclastic differentiation and furthermore enhance the surface expression of receptors for RANKL and M-CSF on RAW264.7 cells. Using murine bone marrow-derived monocytic cells (BMDMCs), we demonstrated that a genetic deficiency of ADAM17 or its required regulator iRhom2 leads to increased osteoclast development in response to M-CSF and RANKL stimulation. Moreover, ADAM17-deficient osteoclast precursor cells express increased levels of the receptors for RANKL and M-CSF. Thus, ADAM17 negatively regulates osteoclast differentiation, most likely through shedding of these receptors. To assess the time-dependent contribution of ADAM10, we blocked this proteinase by adding a specific inhibitor on day 0 of BMDMC stimulation with M-CSF or on day 7 of subsequent stimulation with RANKL. Only ADAM10 inhibition beginning on day 7 increased the size of developing osteoclasts indicating that ADAM10 suppresses osteoclast differentiation at a later stage. Finally, we could confirm our findings in human peripheral blood mononuclear cells (PBMCs). Thus, downregulation of either ADAM10 or ADAM17 during osteoclast differentiation may represent a novel regulatory mechanism to enhance their differentiation process. Enhanced bone resorption is a critical issue in osteoporosis and is driven through osteoclast differentiation by specific osteogenic mediators. The present study demonstrated that the metalloproteinases ADAM17 and ADAM10 critically suppress osteoclast development. This was observed for a murine cell line, for isolated murine bone marrow cells and for human blood cells by either preferential inhibition of the proteinases or by gene knockout. As a possible mechanism, we studied the surface expression of critical receptors for osteogenic mediators on developing osteoclasts. Our findings revealed that the suppressive effects of ADAM17 and ADAM10 on osteoclastogenesis can be explained in part by the proteolytic cleavage of surface receptors by ADAM10 and ADAM17, which reduces the sensitivity of these cells to osteogenic mediators. We also observed that osteoclast differentiation was associated with the downregulation of ADAM10 and ADAM17, which reduced their suppressive effects. We therefore propose that this downregulation serves as a feedback loop for enhancing osteoclast development.
Topics: ADAM17 Protein; ADAM10 Protein; Osteoclasts; Animals; Cell Differentiation; Mice; Down-Regulation; Amyloid Precursor Protein Secretases; Membrane Proteins; Humans; RANK Ligand; RAW 264.7 Cells; Macrophage Colony-Stimulating Factor; Mice, Inbred C57BL
PubMed: 38863060
DOI: 10.1186/s12964-024-01690-y -
Aging Jun 2024The global prevalence of osteoporosis is being exacerbated by the increasing number of aging societies and longer life expectancies. In response, numerous drugs have...
The global prevalence of osteoporosis is being exacerbated by the increasing number of aging societies and longer life expectancies. In response, numerous drugs have been developed in recent years to mitigate bone resorption and enhance bone density. Nonetheless, the efficacy and safety of these pharmaceutical interventions remain constrained. Corylin (CL), a naturally occurring compound derived from the anti-osteoporosis plant L., has exhibited promising potential in impeding osteoclast differentiation. This study aims to evaluate the effect and molecular mechanisms of CL regulating osteoclast differentiation and its potential as a therapeutic agent for osteoporosis treatment . Our investigation revealed that CL effectively inhibits osteoclast formation and their bone resorption capacity by downregulating the transcription factors NFATc1 and c-fos, consequently resulting in the downregulation of genes associated with bone resorption. Furthermore, it has been observed that CL can effectively mitigate the migration and fusion of pre-osteoclast, while also attenuating the activation of mitochondrial mass and function. The results obtained from an study have demonstrated that CL is capable of attenuating the bone loss induced by ovariectomy (OVX). Based on these significant findings, it is proposed that CL exhibits considerable potential as a novel drug strategy for inhibiting osteoclast differentiation, thereby offering a promising approach for the treatment of osteoporosis.
Topics: Animals; Osteoclasts; Osteoporosis; Cell Differentiation; Mice; Bone Resorption; Female; Ovariectomy; NFATC Transcription Factors; RAW 264.7 Cells; Osteogenesis; Flavonoids
PubMed: 38862240
DOI: 10.18632/aging.205885 -
Journal of Extracellular Vesicles Jun 2024Matrix vesicles (MVs) provide the initial site for amorphous hydroxyapatite (HA) formation within mineralizing osteoblasts. Although Na/Ca exchanger isoform-3 (NCX3,...
Matrix vesicles (MVs) provide the initial site for amorphous hydroxyapatite (HA) formation within mineralizing osteoblasts. Although Na/Ca exchanger isoform-3 (NCX3, SLC8A3) was presumed to function as major Ca transporter responsible for Ca extrusion out of osteoblast into the calcifying bone matrix, its presence and functional role in MVs have not been investigated. In this study, we investigated the involvement of NCX3 in MV-mediated mineralization process and its impact on bone formation. Using differentiated MC3T3-E1 cells, we demonstrated that NCX3 knockout in these cells resulted in a significant reduction of Ca deposition due to reduced Ca entry within the MVs, leading to impaired mineralization. Consequently, the capacity of MVs to promote extracellular HA formation was diminished. Moreover, primary osteoblast isolated from NCX3 deficient mice (NCX3) exhibits reduced mineralization efficacy without any effect on osteoclast activity. To validate this in vitro finding, μCT analysis revealed a substantial decrease in trabecular bone mineral density in both genders of NCX3 mice, thus supporting the critical role of NCX3 in facilitating Ca uptake into the MVs to initiate osteoblast-mediated mineralization. NCX3 expression was also found to be the target of downregulation by inflammatory mediators in vitro and in vivo. This newfound understanding of NCX3's functional role in MVs opens new avenues for therapeutic interventions aimed at enhancing bone mineralization and treating mineralization-related disorders.
Topics: Animals; Osteoblasts; Sodium-Calcium Exchanger; Mice; Calcium; Calcification, Physiologic; Mice, Knockout; Male; Osteogenesis; Cell Differentiation; Female; Extracellular Vesicles; Cell Line
PubMed: 38859730
DOI: 10.1002/jev2.12450 -
Nutrition Research and Practice Jun 2024This study evaluated the beneficial effects of an ethanol extract of gum resin (FJH-UBS) in osteoporosis.
BACKGROUND/OBJECTIVES
This study evaluated the beneficial effects of an ethanol extract of gum resin (FJH-UBS) in osteoporosis.
MATERIALS/METHODS
MC3T3-E1 osteoblastic cells and RAW 264.7 osteoclastic cells were treated with FJH-UBS. The alkaline phosphatase (ALP) activity, mineralization, collagen synthesis, osteocalcin content, and Runt-related transcription factor 2 (RUNX2) and Osterix expression were measured in MC3T3-E1 cells. The actin ring structures, tartrate-resistant acid phosphatase (TRAP) activity, and the nuclear factor of activator T-cells, cytoplasm 1 (NFATc1) expression were evaluated in RAW 264.7 cells. Ovariectomized ICR mice were orally administered FJH-UBS for eight weeks. The bone mineral density (BMD) and the serum levels of osteocalcin, procollagen 1 N-terminal propeptide (P1NP), osteoprotegerin, and TRAP 5b were analyzed.
RESULTS
FJH-UBS increased the ALP activity, collagen, osteocalcin, mineralization, and RUNX2 and osterix expression in MC3T3-E1 osteoblastic cells, whereas it decreased the TRAP activity, actin ring structures, and NFATc1 expression in RAW 264.7 osteoclastic cells. In ovariectomy-induced osteoporosis mice, FJH-UBS positively restored all of the changes in the bone metabolism biomarkers (BMD, osteocalcin, P1NP, osteoprotegerin, and TRAP 5b) caused by the ovariectomy.
CONCLUSION
FJH-UBS has anti-osteoporotic activity by promoting osteoblast activity and inhibiting osteoclast activity and , suggesting that FJH-UBS is a potential functional food ingredient for osteoporosis.
PubMed: 38854466
DOI: 10.4162/nrp.2024.18.3.309 -
Bioorganic & Medicinal Chemistry Jun 2024The design and synthesis of N-desmethyl and N-methyl destruxin E analogs have been demonstrated. The X-ray single crystal structure of destruxin E (1a) revealed a stable...
The design and synthesis of N-desmethyl and N-methyl destruxin E analogs have been demonstrated. The X-ray single crystal structure of destruxin E (1a) revealed a stable three-dimensional (3D) structure, including a s-cis amide bond at the MeVal-MeAla moiety and two intramolecular hydrogen bonds between NH(β-Ala) and OC(Ile) and between NH(Ile) and OC(β-Ala). N-Desmethyl analogs 2a (MeAla → Ala) and 2b (MeVal → Val) were synthesized through macrolactonization similar to our previously reported synthesis of 1a. Conversely, for the synthesis of N-methyl analogs 2c (Ile → MeIle) and 2d (β-Ala → Meβ-Ala), macrolactonization did not proceed; therefore, cyclization precursors 10c and 10d were designed to maintain the intramolecular hydrogen bonds described above during their cyclization. The macrolactamization proceeded despite the presence of a less reactive N-methylamino group at the N-terminus in both cases. Analog 2a, which exhibits multiple conformers in solutions, was inactive at 50 μM, whereas analog 2b, which exhibits a conformation similar to that of 1a in solutions, exhibited morphological changes against osteoclast-like multinuclear cells at 1.6 μM. The activity of the MeIle analog 2c, which cannot take the intramolecular hydrogen bond (Ile)NH•••OC(β-Ala) in 1a, was markedly diminished compared with that of 1a, and that of the Meβ-Ala analog 2d, which cannot take the intramolecular hydrogen bond (β-Ala)NH•••OC(Ile) in 1a, was further reduced to one-fourth of that of 2c. The overall results indicate that both the s-cis amide bond at the MeVal-MeAla moiety and two intramolecular hydrogen bonds (β-Ala)NH•••OC(Ile) and (Ile)NH•••OC(β-Ala) are important for constraining the conformation of the macrocyclic peptide backbone in destruxin E, thereby exhibiting its potent biological activity.
Topics: Structure-Activity Relationship; Osteoclasts; Mice; Animals; Crystallography, X-Ray; Molecular Structure; Hydrogen Bonding; Dose-Response Relationship, Drug; Models, Molecular
PubMed: 38852256
DOI: 10.1016/j.bmc.2024.117777 -
Journal of Orthopaedic Surgery and... Jun 2024Fragility fracture is common in the elderly. Osteoblast differentiation is essential for bone healing and regeneration. Expression pattern of long non-coding RNA MIAT...
BACKGROUND
Fragility fracture is common in the elderly. Osteoblast differentiation is essential for bone healing and regeneration. Expression pattern of long non-coding RNA MIAT during fracture healing was examined, and its role in osteoblast differentiation was investigated.
METHODS
90 women with simple osteoporosis and 90 women with fragility fractures were included. Another 90 age-matched women were set as the control group. mRNA levels were tested using RT-qPCR. Cell viability was detected via CCK-8, and osteoblastic biomarkers, including ALP, OCN, Collagen I, and RUNX2 were tested via ELISA. The downstream miRNAs and genes targeted by MIAT were predicted by bioinformatics analysis, whose functions and pathways were annotated via GO and KEGG analysis.
RESULTS
Serum MIAT was upregulated in osteoporosis women with high accuracy of diagnostic efficacy. Serum MIAT was even elevated in the fragility fracture group, but decreased in a time manner after operation. MIAT knockdown promoted osteogenic proliferation and differentiation of MC3T3-E1, but the influences were reversed by miR-181a-5p inhibitor. A total of 137 overlapping target genes of miR-181a-5p were predicted based on the miRDB, TargetScan and microT datasets, which were mainly enriched for terms related to signaling pathways regulating pluripotency of stem cells, cellular senescence, and osteoclast differentiation.
CONCLUSIONS
LncRNA MIAT serves as a promising biomarker for osteoporosis, and promotes osteogenic differentiation via targeting miR-181a-5p.
Topics: RNA, Long Noncoding; Humans; Female; Biomarkers; Fracture Healing; Aged; Cell Differentiation; Osteoblasts; Animals; Mice; MicroRNAs; Osteoporosis; Osteogenesis; Middle Aged; Osteoporotic Fractures; Cell Proliferation; Up-Regulation
PubMed: 38849896
DOI: 10.1186/s13018-024-04824-7 -
Bone Research Jun 2024DNAX-associated protein 12 kD size (DAP12) is a dominant immunoreceptor tyrosine-based activation motif (ITAM)-signaling adaptor that activates costimulatory signals...
DNAX-associated protein 12 kD size (DAP12) is a dominant immunoreceptor tyrosine-based activation motif (ITAM)-signaling adaptor that activates costimulatory signals essential for osteoclastogenesis. Although several DAP12-associated receptors (DARs) have been identified in osteoclasts, including triggering receptor expressed on myeloid cells 2 (TREM-2), C-type lectin member 5 A (CLEC5A), and sialic acid-binding Ig-like lectin (Siglec)-15, their precise role in the development of osteoclasts and bone remodeling remain poorly understood. In this study, mice deficient in Trem-2, Clec5a, Siglec-15 were generated. In addition, mice double deficient in these DAR genes and FcεRI gamma chain (FcR)γ, an alternative ITAM adaptor to DAP12, were generated. Bone mass analysis was conducted on all mice. Notably, Siglec-15 deficient mice and Siglec-15/FcRγ double deficient mice exhibited mild and severe osteopetrosis respectively. In contrast, other DAR deficient mice showed normal bone phenotype. Likewise, osteoclasts from Siglec-15 deficient mice failed to form an actin ring, suggesting that Siglec-15 promotes bone resorption principally by modulating the cytoskeletal organization of osteoclasts. Furthermore, biochemical analysis revealed that Sigelc-15 activates macrophage colony-stimulating factor (M-CSF)-induced Ras-associated protein-1 (RAP1)/Ras-related C3 botulinum toxin substrate 1 (Rac1) pathway through formation of a complex with p130CAS and CrkII, leading to cytoskeletal remodeling of osteoclasts. Our data provide genetic and biochemical evidence that Siglec-15 facilitates M-CSF-induced cytoskeletal remodeling of the osteoclasts.
Topics: Animals; Osteoclasts; Signal Transduction; Macrophage Colony-Stimulating Factor; rap1 GTP-Binding Proteins; Mice; Cytoskeleton; Mice, Knockout; Mice, Inbred C57BL; Membrane Proteins; rac GTP-Binding Proteins; Membrane Glycoproteins; Receptors, Immunologic; Immunoglobulins
PubMed: 38849345
DOI: 10.1038/s41413-024-00340-w -
Cancer Letters Aug 2024Renal cell carcinoma (RCC) bone metastatis progression is driven by crosstalk between tumor cells and the bone microenvironment, which includes osteoblasts, osteoclasts,...
Renal cell carcinoma (RCC) bone metastatis progression is driven by crosstalk between tumor cells and the bone microenvironment, which includes osteoblasts, osteoclasts, and osteocytes. RCC bone metastases (RCCBM) are predominantly osteolytic and resistant to antiresorptive therapy. The molecular mechanisms underlying pathologic osteolysis and disruption of bone homeostasis remain incompletely understood. We previously reported that BIGH3/TGFBI (transforming growth factor-beta-induced protein ig-h3, shortened to BIGH3 henceforth) secreted by colonizing RCC cells drives osteolysis by inhibiting osteoblast differentiation, impairing healing of osteolytic lesions, which is reversible with osteoanabolic agents. Here, we report that BIGH3 induces osteocyte apoptosis in both human RCCBM tissue specimens and in a preclinical mouse model. We also demonstrate that BIGH3 reduces Cx43 expression, blocking gap junction (GJ) function and osteocyte network communication. BIGH3-mediated GJ inhibition is blocked by the lysosomal inhibitor hydroxychloroquine (HCQ), but not osteoanabolic agents. Our results broaden the understanding of pathologic osteolysis in RCCBM and indicate that targeting the BIGH3 mechanism could be a combinational strategy for the treatment of RCCBM-induced bone disease that overcomes the limited efficacy of antiresorptives that target osteoclasts.
Topics: Osteocytes; Humans; Animals; Bone Neoplasms; Carcinoma, Renal Cell; Apoptosis; Kidney Neoplasms; Gap Junctions; Extracellular Matrix Proteins; Mice; Disease Progression; Connexin 43; Cell Line, Tumor; Transforming Growth Factor beta; Osteolysis; Female
PubMed: 38849015
DOI: 10.1016/j.canlet.2024.217009 -
Bioactive Materials Sep 2024Osteoporosis is majorly caused by an imbalance between osteoclastic and osteogenic niches. Despite the development of nationally recognized first-line anti-osteoporosis...
Osteoporosis is majorly caused by an imbalance between osteoclastic and osteogenic niches. Despite the development of nationally recognized first-line anti-osteoporosis drugs, including alendronate (AL), their low bioavailability, poor uptake rate, and dose-related side effects present significant challenges in treatment. This calls for an urgent need for more effective bone-affinity drug delivery systems. In this study, we produced hybrid structures with bioactive components and stable fluffy topological morphology by cross-linking calcium and phosphorus precursors based on mesoporous silica to fabricate nanoadjuvants for AL delivery. The subsequent grafting of -PEG-DAsp ensured superior biocompatibility and bone targeting capacity. RNA sequencing revealed that these fluffy nanoadjuvants effectively activated adhesion pathways through CARD11 and CD34 molecular mechanisms, hence promoting cellular uptake and intracellular delivery of AL. Experiments showed that small-dose AL nanoadjuvants effectively suppress osteoclast formation and potentially promote osteogenesis. results restored the balance between osteogenic and osteoclastic niches against osteoporosis as well as the consequent significant recovery of bone mass. Therefore, this study constructed a drug nanoadjuvant with peculiar topological structures and high bone targeting capacities, efficient intracellular drug delivery as well as bone bioactivity. This provides a novel perspective on drug delivery for osteoporosis and treatment strategies for other bone diseases.
PubMed: 38846529
DOI: 10.1016/j.bioactmat.2024.05.037