Osteoking prevents bone loss and enhances osteoblastic bone formation by modulating the AGEs/IGF-1/ß-catenin/OPG pathway in type 2 diabetic db/db mice.

Type 2 diabetic osteoporosis (T2DOP) is a skeletal metabolic syndrome characterized by impaired bone remodeling due to type 2 diabetes mellitus, and there are drawbacks in the present treatment. Osteoking (OK) is widely used for treating fractures and femoral head necrosis. However, OK is seldom reported in the field of T2DOP, and its role and mechanism of action need to be elucidated. Consequently, this study investigated whether OK improves bone remodeling and the mechanisms of diabetes-induced injury. We used db/db mice as a T2DOP model and stimulated MC3T3-E1 cells (osteoblast cell line) with high glucose (HG, 50 mM) and advanced glycation end products (AGEs, 100 µg/mL), respectively. The effect of OK on T2DOP was assessed using a combined 3-point mechanical bending test, hematoxylin and eosin staining, and enzyme-linked immunosorbent assay. The effect of OK on enhancing MC3T3-E1 cell differentiation and mineralization under HG and AGEs conditions was assessed by an alkaline phosphatase activity assay and alizarin red S staining. The AGEs/insulin-like growth factor-1(IGF-1)/ß-catenin/osteoprotegerin (OPG) pathway-associated protein levels were assayed by western blot analysis and immunohistochemical staining. We found that OK reduced hyperglycemia, attenuated bone damage, repaired bone remodeling, increased tibial and femoral IGF-1, ß-catenin, and OPG expression, and decreased receptor activator of nuclear kappa B ligand and receptor activator of nuclear kappa B expression in db/db mice. Moreover, OK promoted the differentiation and mineralization of MC3T3-E1 cells under HG and AGEs conditions, respectively, and regulated the levels of AGEs/IGF-1/ß-catenin/OPG pathway-associated proteins. In conclusion, our results suggest that OK may lower blood glucose, alleviate bone damage, and attenuate T2DOP, in part through activation of the AGEs/IGF-1/ß-catenin/OPG pathway.

Novel Peptides from Sturgeon Ovarian Protein Hydrolysates Prevent Oxidative Stress-Induced Dysfunction in Osteoblast Cells: Purification, Identification, and Characterization.

This study aimed to explore antioxidant peptides derived from sturgeon (Acipenser schrenckii) ovaries that exhibit antiosteoporotic effects in oxidative-induced MC3T3-E1 cells. The F3-15 component obtained from sturgeon ovarian protein hydrolysates (SOPHs) via gel filtration and RP-HPLC significantly increased the cell survival rate (from 49.38 ± 2.88 to 76.26 ± 2.09%). Two putative antioxidant-acting peptides, FDWDRL (FL6) and FEGPPFKF (FF8), were screened from the F3-15 faction via liquid chromatography-tandem mass spectrometry (LC-MS/MS) and through prediction by computer simulations. Molecular docking results indicated that the possible antioxidant mechanisms of FL6 and FF8 involved blocking the active site of human myeloperoxidase (hMPO). The in vitro tests showed that FL6 and FF8 were equally adept at reducing intracellular ROS levels, increasing the activity of antioxidant enzymes, and protecting cells from oxidative injuries by inhibiting the mitogen-activated protein kinase (MAPK) pathway and activating the phosphoinositide-3 kinase (PI3K)/protein kinase B (AKT)/glycogen synthase kinase-3ß (GSK-3ß) signaling pathway. Moreover, both peptides could increase differentiation and mineralization abilities in oxidatively damaged MC3T3-E1 cells. Furthermore, FF8 exhibited high resistance to pepsin and trypsin, showcasing potential for practical applications.

Hai-Honghua medicinal liquor is a reliable remedy for fracture by promotion of osteogenic differentiation via activation of PI3K/Akt pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Hai-Honghua medicinal liquor (HHML), an external Chinese herbal formula preparation, is often applied to treat freshly closed tibia/fibular fractures, ankle fractures, and other bone-related disorders, but the related molecular mechanism is unclear. AIM OF THE STUDY: To evaluate the therapeutic effect of HHML in patients with tibial/fibular and ankle fractures, and to explore its related possible mechanism. METHODS AND MATERIALS: A total of 182 patients with tibia/fibular fractures and 183 patients with ankle fractures were enrolled in this study. A randomized, controlled, unblinded clinical trial was designed to evaluate the therapeutic effect of HHML on tibial/fibular and ankle fractures. The chemical compositions of HHML were analyzed by the HPLC-Q-Extractive MS/MS. Furthermore, a rat tibial fracture model was established to evaluate the therapeutic effects of HHML in promoting fracture healing, and the mouse embryonic osteoblasts cell line of MC3T3-E1 was further carried out to explore the mechanisms of HHML on osteoblast differentiation. RESULTS: In the clinical evaluation, HHML treatment significantly shortened the time for pain and swelling in patients with tibial/fibular fractures (P < 0.01) and ankle fractures (P < 0.01), and the incidence of complications was significantly reduced as well. Subsequently, 116 constituents were identified from HHML via HPLC-Q-TOF-MS/MS analysis. In vivo, no obvious changes in weight were observed in HHML-treated rats. Moreover, the levels of bone formation markers (including osteocalcin (OCN), N-terminal propeptide of type I procollagen (PINP), alkaline phosphatase (ALP), calcium (Ca) and substance P) in rat serum were significantly increased in HHML-treated rats compared with model rats (P < 0.05). Micro-CT analysis showed bone mineral density (BMD), bone volume fraction (BV/TV), trabecular thickness (Tb.Th) of the HHML-treated rats were significantly increased (P < 0.05, vs. Model) while trabecular separation (Tb.Sp) and structure model index (SMI) values were significantly reduced (P < 0.05, vs. Model). Histological analysis showed that HHML treatment promoted the healing of fractures and cartilage repair, and increased the osteoblasts and collagen fibers. Furthermore, our results also revealed HHML could promote MC3T3-E1 cells proliferation and osteoblast differentiation via regulation of the runt-related transcription factor 2 (RUNX2), bone alkaline phosphatase (BALP), and OCN by activating phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) pathway, which confirmed by adding PI3K chemical inhibitor of LY294002. CONCLUSION: HHML treatment is a reliable remedy for fractures in tibial and ankle by promotion of osteogenic differentiation via activation of PI3K/Akt pathway.

Additive Manufacturing of Wet-Spun Poly(3-hydroxybutyrate-co-3-hydroxyvalerate)-Based Scaffolds Loaded with Hydroxyapatite.

Tissue engineering represents an advanced therapeutic approach for the treatment of bone tissue defects. Polyhydroxyalkanoates are a promising class of natural polymers in this context thanks to their biocompatibility, processing versatility, and mechanical properties. The aim of this study is the development by computer-aided wet-spinning of novel poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)-based composite scaffolds for bone engineering. In particular, PHBV scaffolds are loaded with hydroxyapatite (HA), an osteoinductive ceramic, in order to tailor their biological activity and mechanical properties. PHBV blending with poly(lactide-co-glycolide) (PLGA) is also explored to increase the processing properties of the polymeric mixture used for composite scaffold fabrication. Different HA percentages, up to 15% wt., can be loaded into the PHBV or PHBV/PLGA scaffolds without compromising their interconnected porous architecture, as well as the polymer morphological and thermal properties, as demonstrated by scanning electron microscopy, thermogravimetric analysis, and differential scanning calorimetry. In addition, HA loading results in increased scaffold compressive stiffness to levels comparable to those of trabecular bone tissue, as well as in higher in vitro MC3T3-E1 cell viability and production of mineralized extracellular matrix, in comparison to what observed for unloaded scaffolds. The observed mechanical and biological properties suggest the suitability of the developed scaffolds for bone engineering.

Fabrication of novel nanofiber composed of gelatin/alginate with zirconium oxide NPs regulate orthodontic progression of cartilage degeneration on Wnt/ß-catenin signaling axis in MC3T3-E1 cells.

Natural macromolecules like alginate and gelatin are employed to create medication delivery systems that are both safe and effective. Zirconium nanoparticles (ZrO2 NPs) have been proposed as a means of enhancing the alginate-gelatin hydrogel's physical and biological properties. This study combines the synthesis of the biopolymers gelatin and alginate nanofibers with nanoparticles of zirconium oxide (GA/NF- ZrO2 NPs). UV, XRD, FTIR, and SEM were used to characterize the synthesized nanofibers. The expression of osteogenic genes was analyzed by western blotting and qualitative real-time polymerase chain reaction (qRT-PCR). Based on our findings, MC3T3-E1 cells are performed for cell viability, apoptosis and reactive oxygen species production by GA/NF- ZrO2 NPs through the Wnt/ß-catenin signaling pathway. Cell migration was accelerated at 75 µg/mL concentration after 24 h of damage in a scratch wound healing assay. Proliferation of the MC3T3-E1 cell line was also detected. GA/NF-ZrO2 NPs influenced the osteogenic variation of MC3T3-E1 cells by inducing autophagy. Furthermore, the impact of obstruction on the temporomandibular joint (TMJ) is a subject of ongoing discussion and analysis within the context of animal models. Coordinated GA/NF-ZrO2 NPs on biomaterial nanofibers could be used to introduce physical signals for modifying MC3T3-E1 responds for orthodontic engineering constructs.

Effect and mechanism of recombinant human fibroblast growth factor 18 on osteoporosis in OVX mice.

OBJECTIVES: This study aimed to investigate the effect and the mechanism of recombinant human fibroblast growth factor 18 (rhFGF18) on postmenopausal osteoporosis. METHODS: The effect of rhFGF18 on the proliferation and apoptosis of osteoblasts and the mechanism underlying such an effect was evaluated using an oxidative stress model of the MC3T3-E1 cell line. Furthermore, ovariectomy was performed on ICR mice to imitate estrogen-deficiency postmenopausal osteoporosis. Bone metabolism and bone morphological parameters in the ovariectomized (OVX) mice were evaluated. RESULTS: The results obtained from the cell model showed that FGF18 promoted MC3T3-E1 cell proliferation by activating the extracellular signal-regulated kinase (ERK) and p38 instead of c-Jun N-terminal kinase (JNK). FGF18 also prevented cells from damage inflicted by oxidative stress via inhibition of apoptosis. After FGF18 administration, the expression level of anti-apoptotic protein Bcl-2 in the mice was upregulated, whereas those of the pro-apoptotic proteins Bax and caspase-3 were downregulated. Administering FGF18 also improved bone metabolism and bone morphological parameters in OVX mice. CONCLUSIONS: FGF18 could effectively prevent bone loss in OVX mice by enhancing osteoblastogenesis and protecting osteoblasts from oxidative stress-induced apoptosis.

Liuwei Dihuang Pills Enhance Osteogenic Differentiation in MC3T3-E1 Cells through the Activation of the Wnt/ß-Catenin Signaling Pathway.

OBJECTIVE: The therapeutic efficacy and molecular mechanisms of traditional Chinese medicines (TCMs), such as Liuwei Dihuang pills (LWDH pills), in treating osteoporosis (OP) remain an area of active research and interest in modern medicine. This study investigated the mechanistic underpinnings of LWDH pills in the treatment of OP based on network pharmacology, bioinformatics, and in vitro experiments. METHODS: The active ingredients and targets of LWDH pills were retrieved through the TCMSP database. OP-related targets were identified using the CTD, GeneCards, and DisGeNET databases. The STRING platform was employed to construct a protein-protein interaction (PPI) network, and core targets for LWDH pills in treating OP were identified. The GO functional and KEGG pathway enrichment analyses for potential targets were performed using the R package "clusterProfiler". A "drug-target" network diagram was created using Cytoscape 3.7.1 software. The viability of MC3T3-E1 cells was evaluated using the CCK-8 method after treatment with various concentrations (1.25%, 2.5%, 5%, and 10%) of LWDH pill-medicated serum for 24, 48, and 72 h. Following a 48 h treatment of MC3T3-E1 cells with LWDH pill-medicated serum, the protein levels of collagen Ⅰ, RUNX2, Wnt3, and ß-catenin were quantified using the Western blot analysis, and the activity of alkaline phosphatase (ALP) was measured. RESULTS: A total of 197 putative targets for LWDH pills for OP treatment were pinpointed, from which 20 core targets were singled out, including TP53, JUN, TNF, CTNNB1 (ß-catenin), and GSK3B. The putative targets were predominantly involved in signaling pathways such as the Wnt signaling pathway, the MAPK signaling pathway, and the PI3K-Akt signaling pathway. The intervention with LWDH pill-medicated serum for 24, 48, and 72 h did not result in any notable alterations in the cell viability of MC3T3-E1 cells relative to the control group (all p > 0.05). Significant upregulation in protein levels of collagen Ⅰ, RUNX2, Wnt3, and ß-catenin in MC3T3-E1 cells was observed in response to the treatment with 2.5%, 5%, and 10% of LWDH pill-medicated serum in comparison to that with the 10% rabbit serum group (all p < 0.05). Furthermore, the intervention with LWDH pill-medicated serum resulted in the formation of red calcified nodules in MC3T3-E1 cells, as indicated by ARS staining. CONCLUSIONS: LWDH pills may upregulate the Wnt/ß-catenin signaling pathway to elevate the expression of osteogenic differentiation proteins, including collagen Ⅰ and RUNX2, and to increase the ALP activity in MC3T3-E1 cells for the treatment of OP.

Ginsenoside Rg1 modulates PI3K/AKT pathway for enhanced osteogenesis via GPER.

BACKGROUND: Osteoporosis is a systemic skeletal disorder characterized by decreased bone density and the degradation of bone tissue microarchitecture. Ginsenoside Rg1, derived from Panax ginseng, has been a part of traditional Chinese medicine in China for centuries, particularly for treating osteoporosis. However, there remains limited research on the osteogenic potential of Rg1 within the glucocorticoid-induced osteoporosis (GIOP) model and its specific mechanisms. PURPOSE: The primary objective of this study is to investigate the osteogenic potential of Rg1 within the GIOP model and explore the signaling pathways associated with its in vivo and in vitro effects. METHODS: Cell proliferation, differentiation and mineralization were evaluated by the Cell counting kit 8(CCK8) assay, alkaline phosphatase (ALP) test and Alizarin Red S staining, respectively. The qPCR technique was used to determine the relative expression of mRNA and the western blot was used to determine the relative expression of protein. In vivo experiments, spinal vertebrae staining in zebrafish larvae was accomplished by alizarin red S staining. RESULTS: Zebrafish larvae's hatching, survival, malformation, and heart rate were unaffected by 50 µM of Rg1 in vivo, while the MEC3T3-E1 cell line's proliferation was unaffected by 50 µM of Rg1 in vitro. Meanwhile, Rg1 was shown to improve osteogenic differentiation or bone formation as well as the level of mRNA expression of osteogenic markers in vivo and in vitro. Treatment with Rg1 significantly increased the expression of G protein-coupled estrogen receptor (GPER) and pAKT. In addition, the GPER inhibitor G15 could significantly reduce the mRNA and protein expression levels of GPER and phosphorylated AKT, LY294002, a PI3K/AKT pathway inhibitor, markedly suppresses the expression of phosphorylated AKT, yet shows no significant impact on GPER expression. Both G15 and LY294002 can significantly blocked the Rg1-mediated enhancement of osteogenesis capacity in the GIOP model. In contrast, when both the agonists G1 of GPER and LY294002 were added, G1 increased the relative expression of mRNA and protein of GPER, but not the expression of osteogenic capacity and osteogenic markers. CONCLUSIONS: This study investigates the mineralization effects and mechanisms of Ginsenoside Rg1 both in vitro and in vivo. For the first time, we propose that Rg1 might regulate osteogenesis by modulating AKT phosphorylation through mediating GPER expression within the PI3K/AKT pathway in the GIOP model. This discovery introduces novel targets and avenues for osteoporosis treatment.

Novel Calcium-Binding Peptide from Bovine Bone Collagen Hydrolysates and Its Potential Pro-Osteogenic Activity via Calcium-Sensing Receptor (CaSR).

SCOPE: This paper aims to explore the osteogenic activity and potential mechanism of the peptide-calcium chelate, and provides a theoretical basis for peptide-calcium chelates as functional foods to prevent or improve osteoporosis. METHODS AND RESULTS: In this research, a novel peptide (Phe-Gly-Leu, FGL) with a high calcium-binding capacity is screened from bovine bone collagen hydrolysates (CPs), calcium binding sites of which mainly included carbonyl, amino and carboxyl groups. The FGL-Ca significantly enhances the osteogenic activity of MC3T3-E1 cells (survival rate, differentiation, and mineralization). The results of calcium fluorescence labeling and molecular docking show that FGL-Ca may activate calcium-sensing receptor (CaSR), leading to an increase in intracellular calcium concentration, then enhancing osteogenic activity of MC3T3-E1 cells. Further research found that FGL-Ca significantly promotes the mRNA and protein expression levels of CaSR, transforming growth factor ß (TGF-ß1), TGF-ß-type II receptor (TßRII), Smad2, Smad3, osteocalcin (OCN), alkaline phosphatase (ALP), osteoprotegrin (OPG), and collagen type I (COLI). Subsequently, in the signal pathway intervention experiment, the expression levels of genes and proteins related to the TGF-ß1/Smad2/3 signaling pathway that are promoted by FGL-Ca are found to decrease. CONCLUSIONS: These results suggest that FGL-Ca may activate CaSR, increase intracellular calcium concentration, and activate TGF-ß1/Smad2/3 signaling pathway, which may be one of the potential mechanisms for enhancing osteogenic activity.

Antioxidant and anti-inflammatory effects of selenomethionine promote osteogenesis via Wnt/ß-Catenin pathway.

Background: Recently, the antioxidant properties of the natural compound, selenomethionine (Se-Met), have been recognized. However, its effect on the osteogenic mineralization of the Wnt/ß-Catenin pathway under conditions of oxidative stress and inflammation remain unclear. Methods: This study utilized tert-butyl hydroperoxide (TBHP) to simulate oxidative stress and inflammation. Se-Met was then subsequently used to inhibit these effects in vitro. Results: TBHP induces oxidative stress and inflammatory responses by increasing the expression of reactive oxygen species and NLRP3, whereas decreasing the expression of GPX4, thereby inhibiting the viability of MC3T3-E1 cells. TBHP further promotes lipid peroxidation and damages the ultrastructure of mitochondria. Furthermore, TBHP inhibits the expression levels of ß-Catenin, thereby reducing the activity of the Wnt pathway, which in turn suppresses the osteogenic differentiation and mineralization capacity. Importantly, Se-Met significantly alters the aforementioned responses to enhance expression levels of Wnt pathway-related proteins and improving the osteogenic differentiation and mineralization capacity of the cells. Conclusion: Se-Met enhances antioxidant and anti-inflammatory responses in MC3T3-E1 cells via the Wnt/ß-Catenin signaling pathway to promote osteogenesis. Thus, Se-Met plays a crucial role in the field of bone homeostasis, and presents an opportunity for the future development of novel drugs for treating osteoporosis and maintaining bone stability. However, further detailed preclinical animal studies are required to generate solid and reliable data to aid this development.

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.

5-(3',4'-dihydroxyphenyl)-γ-valerolactone, a microbiota metabolite of flavan-3-ols, activates SIRT1-mediated autophagy to attenuate H2O2-induced inhibition of osteoblast differentiation in MC3T3-E1 cells.

Phenolic compounds are promising agents for the prevention of osteoporosis. 5-(3',4'-dihydroxyphenyl)-γ-valerolactone (DHPV) is the major microbiota metabolite of the flavan-3-ols phenolic compound. Herein, we aimed to investigate the potential mechanisms underlying the effects of DHPV on an osteoblast cell model with H2O2-induced oxidative injury. The MC3T3-E1 cell cultured with H2O2 was used as an oxidative injury model after pretreating with DHPV. Pretreatment with DHPV significantly attenuated cell viability decline, enhanced the activity of alkaline phosphatase and mineralization capacity in MC3T3-E1 cells. Reduced reactive oxygen species (ROS) and malondialdehyde (MDA) levels as well as increased in mitochondrial membrane potential and superoxide dismutase (SOD) activities indicated that DHPV affected both the oxidative and antioxidative processes in the cells. DHPV administration increased the LC3-II/I ratio and Beclin-1 protein levels, thereby promoting autophagy, which perhaps contributes to ROS elimination. However, the inhibition of Sirtuin 1 (SIRT1) by SIRT1 small interfering RNA reduced the protective effect of DHPV or SRT1720, as revealed by the increased ROS and MDA levels and decreased SOD, LC3-II/I ratio and Beclin-1 levels. DHPV may promote autophagy and reduce oxidative stress through the SIRT1-mediated pathway, thereby protecting MC3T3-E1 cells from H2O2-induced oxidative damage.

Curculigo orchioides polysaccharide COP70-1 stimulates osteogenic differentiation of MC3T3-E1 cells by activating the BMP and Wnt signaling pathways.

The crude polysaccharide CO70 isolated from Curculigo orchioides could alleviate ovariectomy-induced osteoporosis in rats. To clarify the bioactive components, a new heteropolysaccharide (COP70-1) was purified from CO70 in this study, which was consisted of ß-D-Manp-(1→, →4)-α-D-Glcp-(1→, →4)-ß-D-Manp-(1→, →3,4)-ß-D-Manp-(1→, →4,6)-ß-D-Manp-(1→, and →4,6)-α-D-Galp-(1→. COP70-1 significantly promoted the osteoblastic differentiation of MC3T3-E1 cells through improving alkaline phosphatase activity, the deposition of calcium as well as up-regulating the expression of osteogenic markers (RUNX2, OSX, BSP, OCN, and OPN). Furthermore, COP70-1 stimulated the expression of critical transcription factors of the BMP and Wnt pathways, including BMP2, p-SMAD1, active-ß-catenin, p-GSK-3ß, and LEF-1. In addition, LDN (BMP pathway inhibitor) and DKK-1 (Wnt pathway inhibitor) suppressed the COP70-1-induced osteogenic differentiation of MC3T3-E1 cells. Therefore, COP70-1 was one of the bioactive constituents of C. orchioides for targeting osteoblasts to treat osteoporosis by triggering BMP/Smad and Wnt/ß-catenin pathways.

Evaluation of toxicity and biocompatibility of a novel Mg-Nd-Gd-Sr alloy in the osteoblastic cell.

BACKGROUND: We investigated the toxicity and biocompatibility of a novel Mg-3Nd-1Gd-0.3Sr-0.2Zn-0.4Zr (abbreviated to Mg-Nd-Gd-Sr) alloy in the osteoblastic cell line MC3T3-E1 as osteoblasts play an important role in bone repair and remodeling. METHODS: We used cytotoxicity tests and apoptosis to investigate the effects of the Mg-Nd-Gd-Sr alloy on osteoblastic cells. Cell bioactivity, cell adhesion, cell proliferation, mineralization, ALP activity, and expression of BMP-2 and OPG by osteoblastic cells were also used to investigate the biocompatibility of Mg-Nd-Gd-Sr alloy. RESULTS: The results showed that the Mg-Nd-Gd-Sr alloy had no obvious cytotoxicity, and did not induce apoptosis to MC3T3-E1 cells. Compared with the control group, the number of adherent cells within 12 h was increased significantly in each experimental group (P < 0.05); the OD value of MC3T3-E1 cells was increased significantly in each experimental group on days 1 and 3 of culture (P < 0.05); the number of mineralized nodules formed in each experimental group was significantly increased (P < 0.05), and ALP activity was significantly increased in each experimental group (P < 0.05). RT-PCR results showed that the mRNA expression of BMP-2 and OPG was significantly higher in each experimental group compared with the control group (P < 0.05). Western blotting showed that the Mg-Nd-Gd-Sr alloy extract significantly increased the protein expression of BMP-2 and OPG compared with the control group (P < 0.05). CONCLUSIONS: Our data indicated that the novel Mg-Nd-Gd-Sr-Zn-Zr alloy had no obvious cytotoxic effects, and did not cause apoptosis to MC3T3-E1 cells; meanwhile it promoted cell adhesion, cell proliferation, mineralization, and ALP activity of osteoblasts. During this process, there was an increase in the expressions of BMP-2 and OPG mRNAs and proteins.

Particulate beta-tricalcium phosphate and hydroxyapatite doped with silver promote in vitro osteoblast differentiation in MC3T3-E1 cells.

BACKGROUND: Calcium phosphates including ß-tricalcium phosphate (ß-TCP) and hydroxyapatite (HAp) have been widely used for bone regeneration application because of their high osteoconductive activities. In addition, various kinds of inorganic ions enhance differentiation, proliferation, and mineralization of osteoblasts. However, information about the effects of silver-doped ß-TCP [ß-TCP (Ag)] and HAp [HAp (Ag)] particles on osteogenic differentiation is not available yet. OBJECTIVE: We focused on the impact of ß-TCP (Ag) and HAp (Ag) particles on the osteogenic differentiation of MC3T3-E1 osteoblast precursor cells. METHODS: MC3T3-E1 osteoblast precursor cells were pre-treated by ß-TCP (Ag) or HAp (Ag). And then the medium was changed to differentiation medium. Subsequently, osteoblast differentiation-related markers were determined. RESULTS: We found that treatment with ß-TCP (Ag) or HAp (Ag) particles increased alkaline phosphatase activity in MC3T3-E1 cells. Expression of osteoblast differentiation-related genes also increased after treatment with ß-TCP (Ag) or HAp (Ag) particles, a response thought to be regulated by zinc finger-containing transcription factor osterix. The ratio of the receptor activator of nuclear factor kappa-B ligand (RANKL) to osteoprotegerin (OPG) was decreased by ß-TCP (Ag) and HAp (Ag) particles. CONCLUSION: Silver doping of ß-TCP and HAp particles is effective for bone regeneration.

Nicotinamide mononucleotide supplementation mitigates osteopenia induced by modeled microgravity in rats.

Exposure to weightlessness causes severe osteopenia, resulting in raised fracture risk. The current study aimed to investigate whether nicotinamide mononucleotide (NMN) supplementation protected against the osteopenia in hindlimb unloading (HLU) rats in vivo and modeled microgravity-induced osteoblastic dysfunction in vitro. The 3-mo-old rats were exposed to HLU and intragastrically administered NMN every 3 days (500 mg/kg body weight) for 4 weeks. NMN supplementation mitigated HLU-induced bone loss, evidenced by greater bone mass and biomechanical properties and better trabecular bone structure. NMN supplementation mitigated HLU-induced oxidative stress, evidenced by greater levels of nicotinamide adenine dinucleotide and activities of superoxide dismutase 2 and lesser malondialdehyde levels. Modeled microgravity stimulation using rotary wall vessel bioreactor in MC3T3-E1 cells inhibited osteoblast differentiation, which was reversed by NMN treatment. Furthermore, NMN treatment mitigated microgravity-induced mitochondrial impairments, evidenced by lesser reactive oxygen species generation and greater adenosine triphosphate production, mtDNA copy number, and activities of superoxide dismutase 2 and Complex I and II. Additionally, NMN promoted activation of AMP-activated protein kinase (AMPK), evidenced by greater AMPKα phosphorylation. Our research suggested that NMN supplementation attenuated osteoblastic mitochondrial impairment and mitigated osteopenia induced by modeled microgravity.

Effects of ethanol pretreatment on osteogenic activity and off-flavors in blue mussel (Mytilus edulis L.) enzymatic hydrolysates.

Aquatic protein hydrolysates have many biological activities, but the off-flavor seriously decreases their commercial acceptability. Therefore, it is important to invest in finding an effective deodorization of aquatic hydrolysates that do not affect activities. In this study, ethanol pretreatment of mussel was applied to establish a new method to deodorize the blue mussel (Mytilus edulis L.) hydrolysates. LC-MS and GC-MS analysis results showed that 87.34% of fatty acids, 83.94% of aldehydes, most volatile flavor compounds including aldehydes, ketones, alcohols, acids, and hydrocarbons were decreased after ethanol pretreatment. Besides, it was found that the enzymatic hydrolysates of mussel with or without ethanol pretreatment showed high osteogenic activity, which induced an increase of 33.65 ± 4.36% and 31.77 ± 5.45% in MC3T3-E1 cell growth. These results suggest that ethanol pretreatment has beneficial potential for improving the flavor aspects of blue mussel peptides which may have the potential to stimulate bone regeneration and formation.

Magnetic Hydroxyapatite Composite Nanoparticles for Augmented Differentiation of MC3T3-E1 Cells for Bone Tissue Engineering.

Progressive aging harms bone tissue structure and function and, thus, requires effective therapies focusing on permanent tissue regeneration rather than partial cure, beginning with regenerative medicine. Due to advances in tissue engineering, stimulating osteogenesis with biomimetic nanoparticles to create a regenerative niche has gained attention for its efficacy and cost-effectiveness. In particular, hydroxyapatite (HAP, Ca10(PO4)6(OH)2) has gained significant interest in orthopedic applications as a major inorganic mineral of native bone. Recently, magnetic nanoparticles (MNPs) have also been noted for their multifunctional potential for hyperthermia, MRI contrast agents, drug delivery, and mechanosensitive receptor manipulation to induce cell differentiation, etc. Thus, the present study synthesizes HAP-decorated MNPs (MHAP NPs) via the wet chemical co-precipitation method. Synthesized MHAP NPs were evaluated against the preosteoblast MC3T3-E1 cells towards concentration-dependent cytotoxicity, proliferation, morphology staining, ROS generation, and osteogenic differentiation. The result evidenced that MHAP NPs concentration up to 10 µg/mL was non-toxic even with the time-dependent proliferation studies. As nanoparticle concentration increased, FACS apoptosis assay and ROS data showed a significant rise in apoptosis and ROS generation. The MC3T3-E1 cells cocultured with 5 µg/mL MHAP NPs showed significant osteogenic differentiation potential. Thus, MHAP NPs synthesized with simple wet chemistry could be employed in bone regenerative therapy.

Functional Expression of Mechanosensitive Piezo1/TRPV4 Channels in Mouse Osteoblasts.

Mechanical stress is an important regulatory factor in bone homeostasis. Mechanical stimulation of osteoblasts has been shown to elicit an increase in the concentration of intracellular free Ca2+ ([Ca2+]i). The pattern of functional expression of mechanosensitive ion channels remains unclear, however. Therefore, the purpose of this study was to investigate the pharmacological characteristics of [Ca2+]i in response to direct mechanical stimulation in osteoblasts. The morphological expression of mechanosensitive ion channels was also examined. Mouse osteoblast-like cells (MC3T3-E1 cells) were loaded with fura-2-acetoxymethyl ester, after which [Ca2+]i was measured. Increased levels of [Ca2+]i were observed in MC3T3-E1 cells in response to direct mechanical stimulation by means of a glass micropipette, but no desensitization. Application of a hypotonic solution also induced an increase in [Ca2+]i but was accompanied by a desensitizing effect. Extracellular Gd3+, GsMTx4, or RN-1734 reversibly inhibited this mechanical stimulation-induced increase in [Ca2+]i, whereas no inhibitory effect was observed with HC030031 or clemizole. When osteoblasts were stimulated with Yoda1, an increase was observed in [Ca2+]i together with a significant desensitizing effect. Immunoreactivity against Piezo1 and TRPV4 channel antibodies was detected in MC3T3-E1 cells. These results suggest that osteoblasts express Piezo1 and TRPV4 channels, which are involved in mechanosensitive processes during mechanical stress.

Morroniside ameliorates glucocorticoid-induced osteoporosis and promotes osteoblastogenesis by interacting with sodium-glucose cotransporter 2.

CONTEXT: Morroniside (MOR) possesses antiosteoporosis (OP) effects, but its molecular target and relevant mechanisms remain unknown. OBJECTIVE: We investigated the effects of MOR on glucocorticoid-induced OP and osteoblastogenesis and its underlying mechanisms. MATERIALS AND METHODS: The effects of MOR (10-100 µM) on the proliferation and differentiation of MC3T3-E1 cells were studied in vitro. The glucocorticoid-induced zebrafish OP model was treated with 10, 20 and 40 µM MOR for five days to evaluate its effects on vertebral bone density and related osteogenic markers. In addition, molecular targets prediction and molecular docking analysis were carried out to explore the binding interactions of MOR with the target proteins. RESULTS: In cultured MC3T3-E1 cells, 20 µM MOR significantly increased cell viability (1.64 ± 0.12 vs. 0.95 ± 0.16; p < 0.01) and cell differentiation (1.57 ± 0.01 vs. 1.00 ± 0.04; p < 0.01) compared to the control group. MOR treatment significantly ameliorated vertebral bone loss in the glucocorticoid-induced OP zebrafish model (0.86 ± 0.02 vs. 0.40 ± 0.03; p < 0.01) and restored the expression of osteoblast-specific markers, including ALP, Runx2 and Col-І. Ligand-based target prediction and molecular docking revealed the binding interaction between MOR and the glucose pockets in sodium-glucose cotransporter 2 (SGLT2). DISCUSSION AND CONCLUSIONS: These findings demonstrated that MOR treatment promoted osteoblastogenesis and ameliorated glucocorticoid-induced OP by targeting SGLT2, which may provide therapeutic potential in managing glucocorticoid-induced OP.