Promotes Osteoblast Differentiation Research Articles

Amlexanox Enforces Osteogenic Differentiation and Bone Homeostasis Through Inhibiting Ubiquitin-Dependent Degradation of β-Catenin.

There was arising osteoporosis from an imbalance in bone remodeling, with excessive differentiation of bone marrow mesenchymal stem cells (BMSCs) into adipocytes instead of osteoblasts. In this study, we found IKKε was upregulated in osteoporotic bone and Ikbke knockdown promoted osteoblast differentiation. We explored amlexanox (AM), a novel IKKε inhibitor, for its effects on osteogenic differentiation and bone homeostasis. AM treatment in mice decreased bone loss, reduced marrow fat, and improved bone microarchitecture, leading to enhanced bone strength. In vitro, AM promoted osteogenesis and suppressed adipogenesis of BMSCs in a dose-dependent manner. Moreover, AM controlled RANKL/OPG expression of BMSC which regulated osteoclast differentiation. Mechanistic explorations revealed AM reinforced Wnt/β-catenin pathway by suppressing ubiquitin-proteasome-dependent degradation of β-catenin. Importantly, AM stimulated osteogenesis in human BMSCs. By promoting osteogenesis at the expense of adipogenesis and hindering osteoclastogenesis, AM offers a promising therapeutic strategy for osteoporosis due to its established safety profile.

Ellagic acid promotes osteoblasts differentiation via activating SMAD2/3 pathway and alleviates bone mass loss in OVX mice

Characterized by bone mass loss, osteoporosis is an orthopedic disease typically found in postmenopausal women and aging individuals. Consistent with its pathogenesis summarized as an imbalance in bone formation/resorption, current pharmacologically therapeutic strategies for osteoporosis mainly aim to promote bone formation or/and inhibit bone resorption. However, few effective drugs with mild clinical side effects have been developed, making it a well-concerned issue to seek appropriate drugs for osteoporosis. In this study, we investigated the effect of ellagic acid (EA) on osteogenesis in vitro and in vivo and searched for its molecular mechanism. Here, we showed that EA promoted osteogenic differentiation of MSCs, increased mRNA and protein expression levels of osteoblast marker genes Runt-related transcription factor2, Osterix, Alkaline phosphatase, Collagen type I alpha 1, Osteopontin and Osteocalcin. Furthermore, ovariectomized mice with orally administered EA (10 mg/kg, 50 mg/kg) had significantly higher bone mass than those in controls. And experiments such as fluorescence double-labeling and enzyme-linked immunosorbent assay also demonstrated that EA could promote osteogenesis in vivo. To probe the molecular mechanism of EA, we performed RNA sequencing analysis using EA-treated BMSCs. Significant up-regulation of SMAD2/3 transcription factors was identified by RNA-seq, and it was confirmed in vitro that EA promoted bone formation by activating the SMAD2/3 signaling pathway. Evidence from our present experiments indicates that EA may be a promising candidate for clinical treatment for osteoporosis in future.

Isolation of Pro-Osteogenic Compounds from Euptelea polyandra That Reciprocally Regulate Osteoblast and Osteoclast Differentiation.

Plants contain a large number of small-molecule compounds that are useful for targeting human health and in drug discovery. Healthy bone metabolism depends on the balance between bone-forming osteoblast activity and bone-resorbing osteoclast activity. In an ongoing study searching for 22 plant extracts effective against osteoporosis, we found that the crude extract of Euptelea polyandra Sieb. et Zucc (E. polyandra) had osteogenic bioactivity. In this study, we isolated two compounds, isoquercitrin (1) and astragalin (2), responsible for osteogenic bioactivity in osteoblastic MC3T3-E1 cells from the leaf of E. polyandra using column chromatography and the spectroscopic technique. This is the first report to isolate astragalin from E. polyandra. Compounds (1) and (2) promoted osteoblast differentiation by increasing alkaline phosphatase (ALP) activity and alizarin red S stain-positive calcium deposition, while simultaneously suppressing tartrate-resistant acid phosphatase (TRAP)-positive osteoclast differentiation in RAW264.7 cells at non-cytotoxic concentrations. Isoquercitrin (1) and astragalin (2) increased the expression of osteoblastic differentiation genes, Osterix, ALP, and Osteoprotegerin in the MC3T3-E1 cells, while suppressing osteoclast differentiation genes, TRAP, Cathepsin K, and MMP 9 in the RAW264.7 cells. These compounds may be ideal targets for the treatment of osteoporosis due to their dual function of promoting bone formation and inhibiting bone resorption.

Isolation, purification, and antiosteoporosis activity of donkey bone collagen from discarded bone and its antioxidant peptides

Oxidative stress plays a crucial role in the development of osteoporosis. In this study, it was observed that donkey bone collagen (DC) at a concentration of 500 μg/mL scavenged 17.89 % of 1,1-Diphenyl-2-picrylhydrazyl (DPPH) free radicals, indicating its antioxidant properties. Additionally, when an oxidative damage osteoblast model was created using H2O2, 100 μg/mL DC demonstrated the ability to enhance cell survival by 27.31 %. Furthermore, 50 μg/mL DC increased the intracellular differentiation marker alkaline phosphatase (ALP) level by 62.65 %. Additionally, the study revealed that DC significantly increased the expression of osteoporosis-related factors in serum and effectively restored the abnormal structure of spongy bone in mice osteoporosis model. Peptides (GGWFL, ANLGPA, and GWFK) isolated from DC through gastrointestinal digestion and subsequent enzymatic purification in vitro demonstrated the ability to safeguard osteoblasts from H2O2-induced damage by reducing intracellular reactive oxygen species (ROS). This protection resulted in enhanced cell survival and promoted osteoblast differentiation. This investigation underscores that DC can shield oxidative damage osteoblast model from oxidative stress, ameliorate osteoporosis, and enhance bone density in mice osteoporosis model. These findings suggest various DC applications in the food and medicine industries.

Nanotextured and drug loaded Neovius Ti6Al4V ELI scaffolds with osteogenesis and anti-cancer potential

IntroductionThe use of Ti6Al4V for orthopedic implants though widely accepted, is 10X stiffer than bone, that leads to stress shielding and aseptic loosening. Further, oral delivery demands significantly large dosage of drugs. To address these twin challenges, we have fabricated open cell porous scaffolds capable of sustained dual drug delivery. Drug delivery from open cell porous Ti6Al4V implants is a promising approach for in situ delivery in orthopedic and dental implant applications. MethodologyIn this study, selective laser melting technology was used to fabricate open cell porous Ti6Al4V ELI scaffolds of 50 % volume fractions with Neovius architecture (NOCL). Electrochemical anodization was used to create micro and nano scale surface features for efficient drug loading. The two payloads: an osteogenic agent (Baicalein) and an anti-cancerous drug (Paclitaxel) were then loaded to different levels for differential release. An osteogenic agent was loaded in the nano reservoirs while paclitaxel was mixed with poloxamer and coated over the scaffold. ResultsThe mechanical stiffness of the designed NOCL lattices is approximately 1.29 ± 0.05 GPa, which is comparable to the human bone. This helps to reduce stress shielding effect. The scaffolds loaded with baicalein and paclitaxel yielded a sustained drug release profiles, releasing 57 % and 79 % of the pharmaceuticals over a 7-day period, respectively. Additionally, the baicalein-loaded nano reservoirs promote osteoblast differentiation in mesenchymal stem cells. As a result, bio-inspired 3D-printed open cell porous titanium scaffolds loaded with dual drugs offer a workable solution to the problems associated with orthopedic implants.

Lactate-induced histone lactylation by p300 promotes osteoblast differentiation.

Lactate, which is synthesized as an end product by lactate dehydrogenase A (LDHA) from pyruvate during anaerobic glycolysis, has attracted attention for its energy metabolism and oxidant effects. A novel histone modification-mediated gene regulation mechanism termed lactylation by lactate was recently discovered. The present study examined the involvement of histone lactylation in undifferentiated cells that underwent differentiation into osteoblasts. C2C12 cells cultured in medium with a high glucose content (4500 mg/L) showed increases in marker genes (Runx2, Sp7, Tnap) indicating BMP-2-induced osteoblast differentiation and ALP staining activity, as well as histone lactylation as compared to those cultured in medium with a low glucose content (900 mg/L). Furthermore, C2C12 cells stimulated with the LDH inhibitor oxamate had reduced levels of BMP-2-induced osteoblast differentiation and histone lactylation, while addition of lactate to C2C12 cells cultured in low glucose medium resulted in partial restoration of osteoblast differentiation and histone lactylation. These results indicate that lactate synthesized by LDHA during glucose metabolism is important for osteoblast differentiation of C2C12 cells induced by BMP-2. Additionally, silencing of p300, a possible modifier of histone lactylation, also inhibited osteoblast differentiation and reduced histone lactylation. Together, these findings suggest a role of histone lactylation in promotion of undifferentiated cells to undergo differentiation into osteoblasts.

Acetyltransferases CBP/p300 Control Transcriptional Switch of β-Catenin and Stat1 Promoting Osteoblast Differentiation.

CREB-binding protein (CBP) (CREBBP) and p300 (EP300) are multifunctional histone acetyltransferases (HATs) with extensive homology. Germline mutations of CBP or p300 cause skeletal abnormalities in humans and mice. However, the precise roles of CBP/p300 in bone homeostasis remain elusive. Here, we report that conditional knockout of CBP or p300 in osteoblasts results in reduced bone mass and strength due to suppressed bone formation. The HAT activity is further confirmed to be responsible for CBP/p300-mediated osteogenesis using A-485, a selective inhibitor of CBP/p300 HAT. Mechanistically, CBP/p300 HAT governs osteogenic gene expression in part through transcriptional activation of β-catenin and inhibition of Stat1. Furthermore, acetylation of histone H3K27 and the transcription factor Foxo1 are demonstrated to be involved in CBP/p300 HAT-regulated β-catenin and Stat1 transcription, respectively. Taken together, these data identify acetyltransferases CBP/p300 as critical regulators that promote osteoblast differentiation and reveal an epigenetic mechanism responsible for maintaining bone homeostasis. © 2023 American Society for Bone and Mineral Research (ASBMR).

Catalpol antagonizes LPS-mediated inflammation and promotes osteoblast differentiation through the miR-124-3p/DNMT3b/TRAF6 axis

BackgroundDysregulated inflammation and osteoblast differentiation are implicated in osteoporosis. Exploring the activity of catalpol in inflammation and osteoblast differentiation deepens the understanding of osteoporosis pathogenesis. MethodsLPS was used to treated hFOB1.19 cells to induce inflammation and repress osteoblast differentiation. FOB1.19 cells were induced in osteoblast differentiation medium and treated with LPS and catalpol. Cell viability was assessed using CCK-8. ALP and Alizarin red S staining were conducted for analyzing osteoblast differentiation. The levels of IL-1β, TNF-α and IL-6 were examined by ELISA. The methylation of TRAF6 promoter was examined through MS-PCR. The binding of miR-124–3p to DNMT3b and DNMT3b to TRAF6 promoter was determined with dual luciferase reporter and ChIP assays. ResultsLPS enhanced secretion of inflammatory cytokines and suppressed osteoblast differentiation. MiR-124–3p and TRAF6 were upregulated and DNMT3b was downregulated in LPS-induced hFOB1.19 cells. Catalpol protected hFOB1.19 cells against LPS via inhibiting inflammation and promoting osteoblast differentiation. MiR-124–3p targeted DNMT3b, and its overexpression abrogated catalpol-mediated protection in LPS-treated hFOB1.19 cells. In addition, DNMT3b methylated TRAF6 promoter to restrain its expression. Catalpol exerted protective effects through suppression of the miR-124–3p/DNMT3b/TRAF6 axis in hFOB1.19 cells. ConclusionCatalpol antagonizes LPS-mediated inflammation and suppressive osteoblast differentiation via controlling the miR-124–3p/DNMT3b/TRAF6 axis.

Strontium-polydopamine hybrid coating to improve antibacterial ability and osseointegration of titanium implants

Poor osseointegration and implant-associated infection of titanium implants have prompted their urgent development. Strontium (Sr) is widely recognized to promote osteoblast differentiation and inhibit osteoclast growth. To this end, this study aimed to develop a Sr-containing polydopamine (PDA)-coated implant with practical antibacterial ability and excellent osseointegration ability to meet clinical applications. This hybrid coating used PDA as an adhesion layer and a carrier for Sr ions. The effects of Sr contents on shear bond strength, in vitro stability, antibacterial ability, and in vitro osteogenic activity of the implant were evaluated. The Sr-doped PDA surface was soaked in simulated body fluid (SBF) at pH 7.4 or 5.0 for a long time (up to 90 days) to evaluate the in vitro stability. The antimicrobial ability of the hybrid coating against E. coli and S. aureus was examined, while its cellular function was assessed using RAW 264.7 and MG63 cells. The current phase and chemical composition results indicated the presence of Sr ions on the surface of PDA. When Sr was added to PDA, the initial shear strength values were comparable to those of the PDA coating. Soaking time reduced the strength values of Sr-containing coatings, especially for 90 days. However, Sr coating significantly reduced the growth of the two bacteria in a dose-dependent manner. Likewise, Sr coating had a significant dose-dependent inhibitory effect on the development of RAW 264.7 cells but improved MG63 osteogenesis. In conclusion, 40 % Sr-containing PDA hybrid coating on titanium implants may be a potential implant in terms of in vitro stability, antibacterial ability, and osteogenic activity.

Extracorporeal shock wave therapy inhibits osteoclast differentiation by targeting NF-κB signaling pathway

BackgroundExtracorporeal shock wave therapy (ESWT) has been reported to promote osteoblast differentiation. However, the role of ESWT on osteoclast differentiation is still elusive.MethodsThis study analyzed the differentiation of osteoclasts in the shock wave group and the control group in vitro, and TRAP staining, RT-PCR, WB assays, and MTT assays were assessed between the two groups. Furthermore, we analyzed the bone formation in these two groups in vivo and micro-CT and trap staining were assessed between the two groups.ResultsWe found that ESWT inhibited osteoclast maturation in vitro and ESW treatment of femur promoted bone formation in vivo. Mechanically, osteoclast differentiation was inhibited as the number of impulses increased and ESWT decreased endogenous levels of NTAFc1 and P65 protein.ConclusionsESWT may be a potential therapy of osteoporosis through NF-κB signaling pathway.

Mechanical stress-induced FGF-2 promotes proliferation and consequently induces osteoblast differentiation in mesenchymal stem cells

Mechanical stimuli serve as crucial regulators of bone mass, promoting bone formation. However, the molecular mechanisms governing how mesenchymal stem cells (MSCs) respond to mechanical cues during their differentiation into osteogenic cells remain elusive. In this study, we found that cyclic stretching enhances MSC proliferation but does not increase the expression of osteoblast-related genes. We further revealed that this proliferative effect is mediated by fibroblast growth factor 2 (FGF-2), synthesized by MSCs in response to mechanical stress. Cell proliferation induced by cyclic stretching was inhibited upon the addition of either U0126, an inhibitor of mitogen-activated protein kinase kinase (MEK), or early growth response 1 (EGR1)-targeting small-hairpin RNA (shRNA), indicating the involvement of the extracellular signal-regulated kinase (ERK)/EGR1 signaling pathway. Osteoblast differentiation, evaluated through ALP activity, osteoblast-related gene expression, and mineralization, was stimulated by recombinant human FGF-2 (rhFGF-2) when applied during the proliferation phase, but not when applied during the differentiation stage alone. Our results suggest that FGF-2 indirectly promotes osteoblast differentiation as a downstream effect of stimulating cell proliferation. For the first time, we demonstrate that cyclic stretching induces MSCs to produce FGF-2, which in turn encourages cell proliferation through an autocrine/paracrine mechanism, consequently leading to osteoblast differentiation.

Sword Bean (Canavalia gladiata) Pods Induce Differentiation in MC3T3-E1 Osteoblast Cells by Activating the BMP2/SMAD/RUNX2 Pathway.

Sword bean (SB) contains various phytochemicals, such as flavonoids, tannins, saponins, and terpenoids. Although the evaluation of its potential functions, including antioxidant, anti-obesity, anti-inflammatory, liver protection, and antiangiogenic activities, has been widely reported, research on their use in osteoporosis prevention is insufficient. Furthermore, while various studies are conducted on SB, research on sword bean pods (SBP) is not yet active, and little is known about it. Therefore, this study investigated the effects of promoting osteoblast differentiation of MC3T3-E1 cells using SB and SBP extracts and their mechanisms. We show that SBP extracts increase osteoblast proliferation, mineralization-activated alkaline phosphatase (ALP), and collagen synthesis activities. Additionally, treatment with SBP extract increased the expression of markers related to osteoblast differentiation, such as ALP, SPARC, RUNX2, COL-I, BMP2, OCN, and OPN. It was confirmed that SBP induces differentiation by activating the BMP2/SMAD/RUNX2 pathway. We also show that SBP is more effective than SB, and SBP may be useful in assimilating bone minerals and preventing osteoporosis.

Molecular mechanism of a novel root-end filling material containing zirconium oxide on the osteogenic/odontogenic differentiation of human osteosarcoma MG-63 cells.

Although the novel root-end filling material containing zirconium oxide (NRFM-Zr) which is hydroxyapatite-based may promote osteoblast differentiation, the molecular mechanism remains unclear. The aim of this study is to investigate it underlying the osteogenic/odontogenic differentiation of human osteosarcoma MG-63 cells induced by NRFM-Zr, compared with calcium silicate-based mineral trioxide aggregate (MTA), and glass ionomer cement (GIC). Firstly, three different types of root filling materials were co-cultured with MG-63 cells, and their cell toxicity, alkaline phosphatase (ALP) activity, and calcium ion concentration were evaluated. Next, gene expression profiling microarray was employed to analyze the impact of the materials on the gene expression profile of MG-63 cells. The results of cell viability revealed that NRFM-Zr group had no significant difference compared to the negative control group. After 5 and 7days of cultivation, both the NRFM-Zr and MTA groups exhibited significantly higher ALP activity compared to the negative control (p < 0.05). Moreover, the NRFM-Zr group had the highest calcium ion concentration, while the GIC group was the lowest (p < 0.05). Gene expression profiling microarray analysis identified 2915 (NRFM-Zr), 2254 (MTA) and 392 (GIC) differentially expressed genes, respectively. GO functional and KEGG pathway analysis revealed that differentially expressed genes of NRFM-Zr, MTA and GIC participated in 8, 6 and 0 differentiation-related pathways, respectively. Comparing the molecular mechanisms of osteogenic/odontogenic differentiation induced by hydroxyapatite-based NRFM-Zr and calcium silicate-based MTA, it was found that they shared similarities in their molecular mechanisms of promoting osteogenic differentiation. NRFM-Zr primarily promotes differentiation and inhibits cell apoptosis, thereby enhancing osteogenic/odontogenic differentiation of MG-63 cells. Furthermore, the inducing efficacy of NRFM-Zr was found to be superior to MTA.

Osteogenic Effects of KY-054, a Novel Coumarin Derivative on Femur Cortical Bone in Ovariectomized Female Rats

Osteoporosis is treated with oral and parenteral bone resorption inhibitors such as bisphosphonates, and parenteral osteogenic drugs including parathyroid hormone (PTH) analogues and anti-sclerostin antibodies. In the present study, we synthesized KY-054, a 4,6-substituted coumarin derivative, and found that it potently promoted osteoblast differentiation with an increase in alkaline phosphatase (ALP) activity at 0.01-1 µM in mouse-derived mesenchymal stem cells (ST2 cells) and rat bone marrow-derived mesenchymal stem cells (BMSCs). In the ovariectomized (OVX) rats, KY-054 (10 mg/kg/d, 8 weeks) increased plasma bone-type ALP activity, suggesting in vivo promoting effects on osteoblast differentiation and/or activation. In dual-energy X-ray absorption (DEXA) scanning, KY-054 significantly increased the distal and diaphyseal femurs areal bone mineral density (aBMD) that was decreased by ovariectomy, indicating its beneficial effects on bone mineral contents (BMC) and/or bone volume (BV). In micro-computed tomography (micro-CT) scanning, KY-054 had no effect on metaphysis trabecular bone loss and microarchitecture parameters weakened by ovariectomy, but instead increased metaphysis and diaphysis cortical bone volume (Ct.BV) and cortical BMC (Ct.BMC) without reducing medullary volume (Med.V), resulting in increased bone strength parameters. It is concluded that KY-054 preferentially promotes metaphysis and diaphysis cortical bone osteogenesis with little effect on metaphysis trabecular bone resorption, and is a potential orally active osteogenic anti-osteoporosis drug candidate.

Osteogenic activity of a micro/nano hierarchical nano-hydroxyapatite coating on zirconium alloy

Micro/nano hierarchical structures and nano-sized hydroxyapatite (nHA) have been proven to play a critical role in promoting osseointegration. However, still, it is a challenge to prepare tightly adherent nHA coatings with micro/nano hierarchical structure, and the correlation between the physicochemical properties of hydroxyapatite (HA) and osteoblasts (OBs) activity at different stages is unclear yet. In this study, the grain refinement of large-sized HA generated by traditional microarc oxidation-hydrothermal treatment was achieved through a simple method of adding Ca/P (Ca2+ and PO43−) to hydrothermal reaction, and micro/nano hierarchical nHA coatings with different crystallinities and grain sizes were prepared on Zr16Nb12Ti alloy. Further, the OBs responses on these coatings were investigated in proliferation and differentiation stages, respectively. It was found that small-sized HA particles provide more integrin-binding sites, which are important for the adhesion and proliferation stages of OBs. The high ion release resulting from the low crystallinity of HA is a crucial condition for promoting OBs differentiation. However, amorphous HA coatings with excessively low crystallinity exhibit poor osteogenic activity due to their inferior cell adhesion activity. Finally, a micro/nano hierarchical nHA coating with appropriate crystallinity was prepared through a simple method, demonstrating excellent osteogenic activity, and providing new strategies for biomimetic coatings research.

Anti-osteoporosis effects of triterpenoids from the fruit of sea buckthorn (Hippophae rhamnoides) through the promotion of osteoblast differentiation in mesenchymal stem cells, C3H10T1/2.

In a previous study, we discovered that the ethanolic extract of sea buckthorn (Hippophae rhamnoides) fruits exhibited anti-osteoporosis effects both in vitro and in vivo. Through bioassay-guided fractionation, we identified the hexane fraction (HRH) as the active fraction, which was further fractionated using preparative HPLC. Among the resulting six fractions, HRHF4 showed significant activity. In the present study, we focused on the bioassay-guided isolation of bioactive compounds from the HRHF4 fraction. We successfully identified the active HRHF43 fraction, which led us to the isolation of potential bioactive compounds (1-6). The chemical structures of these compounds were determined using NMR data, LC-MS analysis, and HR-ESI-MS data as four triterpenes, ursolic acid (1), uvaol (2), oleanolic aldehyde (3), and ursolic aldehyde (4), together with two fatty acids, methyl linoleate (5) and ethyl oleate (6). To evaluate the efficacy of promoting osteoblast differentiation and the expression of mRNA biomarkers related to osteogenesis, we tested the isolated compounds in the mouse mesenchymal stem cell line, C3H10T1/2. Alkaline phosphate staining demonstrated that triterpenes (1-4) displayed osteogenic activity. Particularly noteworthy, ursolic aldehyde (4) exhibited the most potent effect, showing an 11.2-fold higher activity at a concentration of 10μg/mL compared to the negative control. Moreover, ursolic aldehyde (4) upregulated the gene expression of bone formation-related biomarkers, including Runx2, Osterix, Alp, and Osteopontin. These findings suggest that the fruit extract of H. rhamnoides may have potential as a nutraceutical for promoting bone health, with ursolic aldehyde (4) identified as an active constituent.

Germanium/niobium/polyetherketoneketone ternary biocomposite with crisscross micro-nano patterns created by femtosecond laser for enhancing bone-bonding and resisting infection

Loosening and infection are two main reasons for the failure of orthopedic implants. Bone-bonding strengthens the fixation/stability of implants with host bone that extends its service life. Herein, a germanium (Ge)/niobium (Nb)/polyetherketoneketone (PEKK) ternary composite (GNP) was fabricated by melting blend, and crisscross micro-nano patterns on GNP (GNPF) were created by femtosecond laser. The results displayed compared with PEKK and GNP, GNPF with micro-nano patterns displayed remarkable upgradation in surface properties with higher roughness and hydrophilicity/surface energy, etc. GNPF not only promoted osteoblast differentiation but also encouraged the M2 macrophage polarization in vitro. Moreover, GNPF inhibited the bacteria reproduction in vitro, and resisted infection in vivo owing to the sustained release of Ge ion. Further, GNPF remarkably facilitated bone-formation and bone-bonding by inhibiting fibrous capsules in vivo. The mechanism for enhancements of osteoblast response and M2 macrophage polarization in vitro, and bone-bonding in vivo for GNPF was attributed to the cooperative effect of the micro-nano patterns and sustained release of Ge/Nb ions. Consequently, GNPF with osteogenic, anti-inflammatory, and anti-bacterial functions boosted bone-bonding and resisted infection, thereby displaying a promising potential for construction of segmental bone defects.

P7C3 Ameliorates Bone Loss by Inhibiting Osteoclast Differentiation and Promoting Osteogenesis.

Bone homeostasis, the equilibrium between bone resorption and formation, is essential for maintaining healthy bone tissue in adult humans. Disruptions of this process can lead to pathological conditions such as osteoporosis. Dual-targeted agents, capable of inhibiting excessive bone resorption and stimulating bone formation, are being explored as a promising strategy for developing new treatments to address osteoporosis. In this study, we investigated the effects of P7C3 on bone remodeling and its potential therapeutic role in osteoporosis treatment in mice. Specifically, P7C3 can remarkably suppress receptor activator of nuclear factor-κB (NF-κB) ligand (RANKL)-induced osteoclast differentiation in bone marrow macrophages via the Akt-NF-κB-NFATc1 signaling pathway. Additionally, RNA sequencing (RNAseq) analysis revealed that P7C3 promoted osteoblast differentiation and function through the Wnt/β-catenin signaling pathway, thereby enhancing bone formation. Furthermore, μCT analysis and histological examination of bone tissues from P7C3-treated mice showed attenuation of both Ti-induced bone erosion and ovariectomy (OVX)-induced bone loss. These findings suggest that P7C3 may have a novel function in bone remodeling and may be a promising therapeutic agent for the treatment of osteoporosis. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

A new osteogenic protein isolated from Dioscorea opposita Thunb accelerates bone defect healing through the mTOR signaling axis.

Delayed bone defect repairs lead to severe health and socioeconomic impacts on patients. Hence, there are increasing demands for medical interventions to promote bone defect healing. Recombinant proteins such as BMP-2 have been recognized as one of the powerful osteogenic substances that promote mesenchymal stem cells (MSCs) to osteoblast differentiation and are widely applied clinically for bone defect repairs. However, recent reports show that BMP-2 treatment has been associated with clinical adverse side effects such as ectopic bone formation, osteolysis and stimulation of inflammation. Here, we have identified one new osteogenic protein, named 'HKUOT-S2' protein, from Dioscorea opposita Thunb. Using the bone defect model, we have shown that the HKUOT-S2 protein can accelerate bone defect repair by activating the mTOR signaling axis of MSCs-derived osteoblasts and increasing osteoblastic biomineralization. The HKUOT-S2 protein can also modulate the transcriptomic changes of macrophages, stem cells, and osteoblasts, thereby enhancing the crosstalk between the polarized macrophages and MSCs-osteoblast differentiation to facilitate osteogenesis. Furthermore, this protein had no toxic effects in vivo. We have also identified HKUOT-S2 peptide sequence TKSSLPGQTK as a functional osteogenic unit that can promote osteoblast differentiation in vitro. The HKUOT-S2 protein with robust osteogenic activity could be a potential alternative osteoanabolic agent for promoting osteogenesis and bone defect repairs. We believe that the HKUOT-S2 protein may potentially be applied clinically as a new class of osteogenic agent for bone defect healing.

Novel bone Morphogenetic Protein (BMP)-2/4 Consensus Peptide (BCP) for the Osteogenic Differentiation of C2C12 Cells.

Despite the promising clinical potential of bone morphogenetic protein (BMP)-related therapies for bone formation, their side effects warrant the need for alternative therapeutic peptides. BMP family members can aid in bone repair; however, peptides derived from BMP2/ 4 have not yet been investigated. In this study, three candidates BMP2/4 consensus peptide (BCP) 1, 2, and 3 were identified and their ability to induce osteogenesis in C2C12 cells was analyzed. First, an alkaline phosphatase (ALP) staining assay was performed to evaluate the osteogenic effects of BCPs. Next, the effects of BCPs on RNA expression levels and protein abundances of osteogenic markers were explored. Furthermore, the transcriptional activity of ALP by BCP1 and in silico molecular docking model on BMP type IA receptor (BRIA) were performed. BCP1-3 induced higher RUNX2 expression than BMP2. Interestingly, among them, BCP1 significantly promoted osteoblast differentiation more than BMP2 in ALP staining with no cytotoxicity. BCP1 significantly induced the osteoblast markers, and the highest RUNX2 expression was observed at 100 ng/mL compared to other concentrations. In transfection experiments, BCP1 stimulated osteoblast differentiation via RUNX2 activation and the Smad signaling pathway. Finally, in silico molecular docking suggested the possible binding sites of BCP1 on BRIA. These results show that BCP1 promotes osteogenicity in C2C12 cells. This study suggests that BCP1 is the most promising candidate peptide to replace BMP2 for osteoblast differentiation.