Mijiao formula regulates NAT10-mediated Runx2 mRNA ac4C modification to promote bone marrow mesenchymal stem cell osteogenic differentiation and improve osteoporosis in ovariectomized rats.

ETHNOPHARMACOLOGICAL RELEVANCE: The Mijiao (MJ) formula, a traditional herbal remedy, incorporates antlers as its primary constituent. It can effectively treat osteoporosis (OP), anti-aging, enhance immune activity, and change depression-like behavior. In this study, we investigated that MJ formula is a comprehensive treatment strategy, and may provide a potential approach for the clinical treatment of postmenopausal osteoporosis. AIM OF THE STUDY: The purpose of this study was to determine whether MJ formula promoted osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) and improved osteoporosis in ovariectomized rats by regulating the NAT10-mediated Runx2 mRNA ac4C modification. MATERIALS AND METHODS: Female Sprague-Dawley (SD) rats were used to investigate the potential therapeutic effect of MJ formula on OP by creating an ovariectomized (OVX) rat model. The expression of osteogenic differentiation related proteins in BMSCs was detected in vivo, indicating their role in promoting bone formation. In addition, the potential mechanism of its bone protective effect was explored via in vitro experiments. RESULTS: Our study showed that MJ formula significantly mitigated bone mass loss in the OVX rat model, highlighting its potential as an OP therapeutic agent. We found that the possible mechanism of action was the ability of this formulation to stabilize Runx2 mRNA through NAT10-mediated ac4C acetylation, which promoted osteogenic differentiation of BMSCs and contributed to the enhancement of bone formation. CONCLUSIONS: MJ formula can treat estrogen deficiency OP by stabilizing Runx2 mRNA, promoting osteogenic differentiation and protecting bone mass. Conceivably, MJ formulation could be a safe and promising strategy for the treatment of osteoporosis.

Runx2 Regulates Galnt3 and Fgf23 Expressions and Galnt3 Decelerates Osteoid Mineralization by Stabilizing Fgf23.

Runx2 (runt related transcription factor 2) is an essential transcription factor for osteoblast proliferation and differentiation. Uridine diphosphate (UDP)-N-acetylgalactosamine (GalNAc): polypeptide GalNAc-transferase 3 (Galnt3) prevents proteolytic processing of fibroblast growth factor 23 (Fgf23), which is a hormone that regulates the serum level of phosphorus. Runx2 and Galnt3 were expressed in osteoblasts and osteocytes, and Fgf23 expression was restricted to osteocytes in bone. Overexpression and knock-down of Runx2 upregulated and downregulated, respectively, the expressions of Galnt3 and Fgf23, and Runx2 directly regulated the transcriptional activity of Galnt3 in reporter assays. The expressions of Galnt3 and Fgf23 in osteoblast-specific Runx2 knockout (Runx2fl/flCre) mice were about half those in Runx2fl/fl mice. However, the serum levels of phosphorus and intact Fgf23 in Runx2fl/flCre mice were similar to those in Runx2fl/fl mice. The trabecular bone volume was increased during aging in both male and female Galnt3-/- mice, but the osteoid was reduced. The markers for bone formation and resorption in Galnt3-/- mice were similar to the control in both sexes. Galnt3-/- mice exhibited hyperphosphatemia and hypercalcemia, and the intact Fgf23 was about 40% that of wild-type mice. These findings indicated that Runx2 regulates the expressions of Galnt3 and Fgf23 and that Galnt3 decelerates the mineralization of osteoid by stabilizing Fgf23.

Shh-Gli2-Runx2 inhibits vascular calcification.

BACKGROUND: In patients with chronic kidney disease (CKD), vascular calcification (VC) is common and is associated with a higher risk of all-cause mortality. Shh, one ligand for Hedgehog (Hh) signaling, participates in osteogenesis and several cardiovascular diseases. However, it remains unclear whether Shh is implicated in the development of VC. METHODS: Inorganic phosphorus 2.6 mM was used to induce vascular smooth muscle cells (VSMCs) calcification. Mice were fed with adenine diet supplement with 1.2% phosphorus to induce VC. RESULTS: Shh was decreased in VSMCs exposed to inorganic phosphorus, calcified arteries in mice fed with an adenine diet, as well as radial arteries from patients with CKD presenting VC. Overexpression of Shh inhibited VSMCs ostosteoblastic differentiation and calcification, whereas its silencing accelerated these processes. Likewise, mice treated with smoothened agonist (SAG; Hh signaling agonist) showed alleviated VC, and mice treated with cyclopamine (CPN; Hh signaling antagonist) exhibited severe VC. Additionally, overexpression of Gli2 significantly reversed the pro-calcification effect of Shh silencing on VSMCs, suggesting that Shh inhibited VC via Gli2. Mechanistically, Gli2 interacted with Runx2 and promoted its ubiquitin proteasomal degradation, therefore protecting against VC. Of interest, the pro-degradation effect of Gli2 on Runx2 was independent of Smurf1 and Cullin4B. CONCLUSIONS: Our study provided deeper insight to the pathogenesis of VC, and Shh might be a novel potential target for VC treatment.

Explorating the mechanism of Epimedii folium-Rhizoma drynariae herbal pair promoted bone defects healing through network pharmacology and experimental studies.

ETHNOPHARMACOLOGICAL RELEVANCE: Bone defects are difficult to treat and have a high incidence of nonunion. The Epimedii folium-Rhizoma drynariae herbal pair (EDP) is a traditional Chinese medicine (TCM) used for treating bone diseases. However, the mechanisms by which EDP promotes osteogenesis or bone formation remain largely unclear. AIM OF THE STUDY: This study aimed to investigate the mechanism of EDP promoted bone formation in bone defects using network pharmacology and experiments. MATERIALS AND METHODS: The chemical components of EDP were analyzed by UHPLC-MS. The hub target and pathway enrichment analysis was conducted using molecular docking or network pharmacology. The pharmacological actions of EDP were determined by µCT and histopathology examination using a bone defect rat model. The effects of EDP on the mRNA expression of Bmp2, Smad2/5, Runx2, and Alp genes were measured by RT-PCR, while changes in the protein expressions of BMP2, COL1A1, SPP1, ALP, and RUNX2in the tibia tissues of the rats in response to EDP were analyzed by immunohistochemical staining or Western blot. We also performed cell viability assays, Alizarin Red and ALP staining assays, and RT-PCR to better understand how EDP affected osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). RESULTS: Identified 14 key compounds and 47 hub targets of EDP that may be involved in promoting osteogenesis to repair bone defects. And the BMP/Smad/Runx2 pathway was likely the key pathway through which EDP promoted bone defects repairing. The results of in vivo rat experiments indicated that EDP effectively promoted tibia repair in the model rats and activated the BMP/Smad/Runx2 pathway in the tibia tissue, with upregulating Bmp2, Bmpr1α, Smad2/5, Runx2, and Alp genes, and increased the protein expression of BMP2, COL1A1, RUNX2, and ALP. In vitro, EDP was found to increase the proliferation, differentiation, and mineralization in BMSCs- and also up-regulated the expression of key genes in the BMP/Smad/Runx2 pathway. CONCLUSION: This study highlighted the ability of EDP to promote the osteogenic differentiation to enable bone repair by activating the BMP/Smad/Runx2 pathway.

[Effect of Erxian Decoction-containing serum on H_2O_2-induced proliferation and osteogenic differentiation of MC3T3-E1 cells via BK channels].

This study aimed to investigate the effects of Erxian Decoction(EXD)-containing serum on the proliferation and osteogenic differentiation of MC3T3-E1 cells under oxidative stress through BK channels. The oxidative stress model was induced in MC3T3-E1 cells by H_2O_2, and 3 mmol·L~(-1) tetraethylammonium(TEA) chloride was used to block the BK channels in MC3T3-E1 cells. MC3T3-E1 cells were divided into a control group, a model group, an EXD group, a TEA group, and a TEA+EXD group. After MC3T3-E1 cells were treated with corresponding drugs for 2 days, 700 µmol·L~(-1) H_2O_2 was added for treatment for another 2 hours. CCK-8 assay was used to detect cell proliferation activity. The alkaline phosphatase(ALP) assay kit was used to detect the ALP activity of cells. Western blot and real-time fluorescence-based quantitative PCR(RT-qPCR) were used to detect protein and mRNA expression, respectively. Alizarin red staining was used to detect the mineralization area of osteoblasts. The results showed that compared with the control group, the model group showed significantly blunted cell proliferation activity and ALP activity, reduced expression of BK channel α subunit(BKα), collagen Ⅰ(COL1), bone morphogenetic protein 2(BMP2), osteoprotegerin(OPG), and phosphorylated Akt, decreased mRNA expression levels of Runt-related transcription factor 2(RUNX2), BMP2, and OPG, and declining area of calcium nodules. EXD-containing serum could significantly potentiate the cell proliferation activity and ALP activity, up-regulate the protein expression of BKα, COL1, BMP2, OPG, and phosphorylated Akt, and forkhead box protein O1(FoxO1), promote the mRNA expression of RUNX2, BMP2, and OPG, and enlarge the area of calcium nodules. However, BK channel blockage by TEA reversed the effects of EXD-containing serum in promoting the protein expression of BKα, COL1, BMP2, OPG, and phosphorylated Akt and FoxO1, increasing the mRNA expression of RUNX2, BMP2, and OPG, and enlarging the area of calcium nodules. EXD-containing serum could improve the proliferation activity, osteogenic differentiation, and mineralization ability of MC3T3-E1 cells under oxidative stress, which might be related to the regulation of BK channels and downstream Akt/FoxO1 signaling pathway.

Methoxyflavones isolated from the whole plant of Scutellaria rubropunctata Hayata var. rubropunctata promote osteoblast differentiation in MC3T3-E1 cells.

In this study, we isolated two new methoxyflavones (1 and 2) and eight known methoxyflavones (3-10) from the whole plant of Scutellaria rubropunctata Hayata var. rubropunctata (SR). Based on spectroscopic analyses, the methoxyflavones were identified as 5,8,2',6'-tetramethoxy-6,7-methylenedioxyflavone (1) and 5,2',6'-trimethoxy-6,7-methylenedioxyflavone (2). We reported SR might have effects on promoting osteoblast differentiation and stimulating estrogen receptor (ER) in the previous study. Then, the effects of 1-10 on pre-osteoblast MC3T3-E1 cells were investigated, and 1, 2, and 9 were observed to promote alkaline phosphatase activity. To evaluate their effect on osteogenesis-related genes, we performed gene expression analysis using quantitative real-time PCR after treatment of MC3T3-E1 cells with these compounds. Although 2 was only effective at lower concentrations, 1 and 9 upregulated the mRNA levels of Runx2, Osterix, Osteopontin, Osteocalcin, Smad1, and Smad4. These results indicate that 1 and 9 may induce osteoblast differentiation by activating Runx2 via the BMP/Smad pathway and may play a central role in the promotion of osteoblast differentiation by SR. The ER agonist activity of 1-10 were tested using a luciferase reporter assay in HEK293 cells. However, none of the compounds exhibited remarkable activity. Thus, SR may contain other compounds that contribute to its ER agonist activity.

Effectiveness of Apigenin, Resveratrol, and Curcumin as Adjuvant Nutraceuticals for Calvarial Bone Defect Healing: An In Vitro and Histological Study on Rats.

Bone healing is a major clinical issue, especially in bone defects of critical dimensions. Some studies have reported in vivo positive effects on bone healing by some bioactive compounds, such as the phenolic derivatives found in vegetables and plants, such as resveratrol, curcumin, and apigenin. The aim of this work was (1) to analyze in vitro in human dental pulp stem cells the effects of these three natural compounds on the gene expression of related genes downstream to RUNX2 and SMAD5, key factor transcriptions associated with osteoblast differentiation, in order to better understand the positive effects that can occur in vivo in bone healing, and (2) to evaluate in vivo the effects on bone healing of critical-size defects in the calvaria in rats of these three nutraceuticals tested in parallel and for the first time administered by the gastric route. Upregulation of the RUNX2, SMAD5, COLL1, COLL4, and COLL5 genes in the presence of apigenin, curcumin, and resveratrol was detected. In vivo, apigenin induced more consistent significant bone healing in critical-size defects in rat calvaria compared to the other study groups. The study findings encourage a possible therapeutic supplementation with nutraceuticals during the bone regeneration process.

Er-xian decoction drug-containing serum promotes Mc3t3-e1 cell proliferation and osteogenic differentiation via regulating BK channel.

ETHNOPHARMACOLOGICAL RELEVANCE: Er-xian Decoction (EXD) is a well-known prescription widely used to prevent and treat climacteric syndrome and osteoporosis in China. BK channel positively affects osteoblast bone formation in vitro. However, it is still unclear whether the effect of EXD on promoting osteoblasts osteogenic differentiation is related to BK channel. AIM OF THE STUDY: The study is aimed at determining whether the EXD-containing serum promotes the proliferation of osteoblasts and their differentiation through BK channel. MATERIALS AND METHODS: The chemical compounds of EXD were analyzed by UPLC-Q-TOF/MS. An osteogenic induction medium (OM) was used to induce MC3T3-E1 cells' osteogenic differentiation. The effects of EXD-containing serum and tetraethylammonium (TEA) on the proliferation activity of Mc3t3-e1 cells were detected by CCK-8 assay. ALP activity was determined by an alkaline phosphatase kit. The protein expression (BMP2, OPG, and COL1) was analyzed by Western blot, and the mRNA expression (Runx2, OPG, and BMP2) was assessed by real-time PCR. Alizarin red was used to stain the mineralized region of osteoblasts. In addition, we analyzed the relationship between BK channel and its downstream PTEN/Akt/Foxo1 signaling pathway. RESULTS: 72 compounds were identified by UPLC-Q-TOF/MS analysis in EXD. Mangiferin, ferulic acid, berberine, and icariin were main active components of EXD. EXD-containing serum could enhance the cell viability of MC3T3-E1 cells by decreasing the expression of BKα protein. EXD-containing serum increased ALP activity and calcium nodule formation of Mc3t3-e1 cells, promoted the protein expression of BKα, COL1, BMP2, OPG, and the mRNA expression of RUNX2, OPG, and BMP2, however, these effects can be reversed after adding TEA. In addition, EXD-containing serum could upregulate phosphorylation of Akt and Foxo1 in osteogenic-induced Mc3t3-e1 cells, and lower the expression of PTEN. And these effects of EXD-containing serum could be reduced by TEA. CONCLUSIONS: The effect of EXD-containing serum on promoting cell proliferation and osteogenic differentiation of Mc3t3-e1 cells might be linked to the regulation of BK channel.

Suffruticosol B Is an Osteogenic Inducer through Osteoblast Differentiation, Autophagy, Adhesion, and Migration.

Suffruticosol B (Suf-B) is a stilbene found in Paeonia suffruticosa ANDR., which has been traditionally used in medicine. Stilbenes and their derivatives possess various pharmacological effects, such as anticancer, anti-inflammatory, and anti-osteoporotic activities. This study aimed to explore the bone-forming activities and mechanisms of Suf-B in pre-osteoblasts. Herein, >99.9% pure Suf-B was isolated from P. suffruticosa methanolic extracts. High concentrations of Suf-B were cytotoxic, whereas low concentrations did not affect cytotoxicity in pre-osteoblasts. Under zero levels of cytotoxicity, Suf-B exhibited bone-forming abilities by enhancing alkaline phosphatase enzyme activities, bone matrix calcification, and expression levels with non-collagenous proteins. Suf-B induces intracellular signal transduction, leading to nuclear RUNX2 expression. Suf-B-stimulated differentiation showed increases in autophagy proteins and autophagosomes, as well as enhancement of osteoblast adhesion and transmigration on the ECM. These results indicate that Suf-B has osteogenic qualities related to differentiation, autophagy, adhesion, and migration. This also suggests that Suf-B could have a therapeutic effect as a phytomedicine in skeletal disorders.

[Efficacy and mechanism of low glycoside from Epimedii Folium flavonoids on retinoic acid-induced osteoporosis in rats].

In this study, the secondary osteoporosis model was induced by oral administration of retinoic acid for two weeks in SD male rats. The efficacy and mechanism of LG on secondary osteoporosis in rats were explored through the bone morphogenetic protein 2(BMP-2)/Runt-related transcription factor 2(Runx2)/Osterix signaling pathway. With Xianling Gubao Capsules(XLGB) as the positive control, three dose groups of low glycoside from Epimedii Folium flavonoids(LG), i.e., low-dose group(LG-L), medium-dose group(LG-M), and high-dose group(LG-H), were set up. After modeling, the rats in each group were treated correspondingly by gavage for eight weeks. The action target of LG in the treatment of secondary osteoporosis in rats was analyzed by measuring the body weight and the organ indexes of rats including heart index and testis index. The efficacy of LG was characterized by the pathological changes of the femur, the microstructural parameters of the trabecular bone, and the biomechanical properties of femoral tissues in rats. The mechanism of LG was explored by measuring the relevant biochemical indexes and the changes in BMP-2, Runx2, and Osterix content in rats with secondary osteoporosis. The results showed that the action target of LG in the treatment of secondary osteoporosis in rats was the testis. LG can improve the bone loss of the femur, increase the number and thickness of the trabecular bone, reduce the porosity and separation of the trabecular bone, potentiate the resistance of bone to deformation and destruction, up-regulate the serum content of Ca, P, aminoterminal propeptide of type Ⅰ procollagen(PINP), and osteocalcin(OC), promote bone matrix calcification and the expression of BMP-2, Runx2, and Osterix proteins, and accelerate bone formation, thereby reducing the risk of fractures, and ultimately exerting anti-secondary osteoporosis efficacy.

Total flavonoids of Rhizoma Drynariae enhances CD31hiEmcnhi vessel formation and subsequent bone regeneration in rat models of distraction osteogenesis by activating PDGF­BB/VEGF/RUNX2/OSX signaling axis.

Total flavonoids of Rhizoma Drynariae (TFRD), extracted from the kidney­tonifying Traditional Chinese medicine Rhizoma Drynariae, can be effective in treating osteoporosis, bone fractures and defects. However, the pharmacological effects of TFRD on the specific vessel subtype CD31hiEmcnhi during distraction osteogenesis (DO) remains unclear. The present study aimed to investigate the effects of TFRD on CD31hiEmcnhi vessels in a rat model of DO. In the present study, tibial DO models were established using 60 rats with a distraction rate of 0.2 mm per day for 20 days. Co­immunofluorescence staining of CD31 and endomucin (Emcn) was conducted to determine CD31hiEmcnhi vessels. Radiographic, angiographic and histological analyses were performed to assess bone and vessel formation. Tube formation, alkaline phosphatase (ALP) and Von Kossa staining assays were performed to test angiogenesis of endothelial precursor cells (EPCs) and osteogenesis of bone marrow­derived mesenchymal stem cells (BMSCs). Additionally, expression levels of platelet­derived growth factor (PDGF)­BB, VEGF, runt­related transcription factor 2 (RUNX2) and Osterix (OSX) were determined by western blotting and reverse transcription­quantitative PCR. The in vivo assays demonstrated that TFRD markedly promoted CD31hiEmcnhi vessel formation during DO, whereas PDGF­BB neutralizing antibody suppressed vessel formation. Furthermore, the ALP, Von Kossa staining and tube formation assays indicated that TFRD notably elevated the angiogenic capacity of EPCs and osteogenic capacity of BMSCs under stress conditions, which was significantly suppressed by blocking PDGF­BB. The protein and mRNA levels of PDGF­BB, VEGF, RUNX2 and OSX were upregulated by TFRD, but downregulated by blocking PDGF­BB. Thus, TFRD could facilitate CD31hiEmcnhi vessel formation and subsequently enhance angiogenic­osteogenic coupling to regenerate bone defects during DO via the PDGF­BB/VEGF/RUNX2/OSX signaling axis, which indicated that CD31hiEmcnhi vessels could be a potential novel therapeutic target for DO, and TFRD may represent a promising drug for promoting bone regeneration in DO by increasing CD31hiEmcnhi vessels.

Effects of Scoparone on differentiation, adhesion, migration, autophagy and mineralization through the osteogenic signalling pathways.

Scoparone (SCOP), an active and efficient coumarin compound derived from Artemisia capillaris Thunb, has been used as a traditional Chinese herbal medicine. Herein, we investigated the effects of SCOP on the osteogenic processes using MC3T3-E1 pre-osteoblasts in in vitro cell systems. SCOP (C11 H10 O4 , > 99.17%) was purified and identified from A. capillaries. SCOP (0.1 to 100 µM concentrations) did not have cytotoxic effects in pre-osteoblasts; however, it promoted alkaline phosphatase (ALP) staining and activity, and mineralized nodule formation under early and late osteogenic induction. SCOP elevated osteogenic signals through the bone morphogenetic protein 2 (BMP2)-Smad1/5/8 pathway, leading to the increased expression of runt-related transcription factor 2 (RUNX2) with its target protein, matrix metallopeptidase 13 (MMP13). SCOP also induced the non-canonical BMP2-MAPKs pathway, but not the Wnt3a-ß-catenin pathway. Moreover, SCOP promoted autophagy, migration and adhesion under the osteogenic induction. Overall, the findings of this study demonstrated that SCOP has osteogenic effects associated with cell differentiation, adhesion, migration, autophagy and mineralization.

Induced pluripotent stem cells from homozygous Runx2-deficient mice show poor response to vitamin D during osteoblastic differentiation.

Cleidocranial dysplasia (CCD) is a hereditary disorder associated with skeletal dysplasia and dental abnormalities. CCD arises from heterozygous loss of function mutations in the Runt-related transcription factor 2 (RUNX2) gene. Osteoporosis is often observed in CCD patients and conventional vitamin D supplementation is recommended. However, sufficient evidences have not been presented yet. This study investigated the role of RUNX2 in osteoblastic differentiation and sought to identify potential target genes for the treatment of osteoporosis associated with CCD, using induced pluripotent stem cell (iPSC) technology. We successfully established Runx2-/-, Runx2+/- and wild-type miPSCs from litter-matched mice and found poor Vdr expression in Runx2-/-cells. Significant down-regulation of osteoblastic differentiation in Runx2-/- miPSCs was observed. Gene expression array revealed unexpected results such as remarkable increase of Rankl expression and decrease of Vdr in Runx2-/- cells. Insufficient response to vitamin D in Runx2-/- cells was also observed. Our results suggest that RUNX2 functions as a regulator of Rankl and Vdr and thereby controls bone density. These findings also suggest that conventional vitamin D supplementation may not be as effective as previously expected, in the treatment of osteoporosis associated with CCD, and that inhibiting RANKL function might be worth considering as an alternative treatment strategy.

Modulatory activity of a bovine hydrolyzed collagen-hydroxyapatite food complex on human primary osteoblasts after simulating its gastrointestinal digestion and absorption.

Introduction: Introduction: osteoporosis is the most prevalent bone disease and one of the main causes of chronic disability in middle and advanced ages. Conventional pharmacological treatments are still limited, and their prolonged use can cause adverse effects that motivate poor adherence to treatment. Nutritional strategies are traditionally based on supplementing the diet with calcium and vitamin D. Recent studies confirm that the results of this supplementation are significantly improved if it is accompanied by the intake of oral hydrolyzed collagen. Objective: to evaluate the possible in vitro osteogenic activity of a peptide-mineral complex formed by bovine hydrolyzed collagen and bovine hydroxyapatite (Phoscollagen®, PHC®). Methods: the digestion and absorption of PHC® were simulated using the dynamic gastrointestinal digester of AINIA and Caco-2 cell model, respectively. Primary cultures of human osteoblasts were treated with the resulting fraction of PHC® and changes were evaluated in the proliferation of preosteoblasts and in the mRNA expression of osteogenic biomarkers at different stages of osteoblast maturation: Runt-related transcription factor 2 (Runx2), alkaline phosphatase (ALP), osteocalcin (OC) and type I collagen (ColA1). Results: an increase in preosteoblastic proliferation was observed (p ≤ 0,05). No changes were detected in the biomarkers of osteoblasts with 5 days of differentiation, but were with 14 days, registering an increase in Runx2 (p = 0.0008), ColA1 (p = 0.035), OC (p = 0.027) and ALP (without significance). Conclusion: these results show that the PHC® peptide-mineral complex stimulates the activity of mature osteoblasts, being capable of promoting bone formation.

Introducción: Introducción: la osteoporosis es la enfermedad ósea más prevalente y una de las principales causas de discapacidad crónica en las edades medias y avanzadas. Los tratamientos farmacológicos convencionales aún son limitados y su uso prolongado puede provocar efectos adversos que motiven baja adherencia al tratamiento. Las estrategias nutricionales se basan tradicionalmente en suplementar la dieta con calcio y vitamina D. Estudios recientes confirman que los resultados de esta suplementación mejoran significativamente si se acompaña de la ingesta de colágeno hidrolizado oral. Objetivo: evaluar la posible actividad osteogénica in vitro de un complejo péptido-mineral formado por colágeno hidrolizado e hidroxiapatita bovinos (Phoscollagen®, PHC®). Métodos: se simuló la digestión y absorción de PHC® utilizando el digestor dinámico gastrointestinal de AINIA y el modelo celular Caco-2, respectivamente. Cultivos primarios de osteoblastos humanos se trataron con la fracción resultante de PHC® y se evaluaron los cambios en la proliferación de los preosteoblastos y en la expresión del ARNm de los biomarcadores osteogénicos en diferentes etapas de maduración de los osteoblastos: factor de transcripción 2 relacionado con Runt (Runx2), fosfatasa alcalina (ALP), osteocalcina (OC) y colágeno tipo I (ColA1). Resultados: se observó un incremento de la proliferación preosteoblástica (p ≤ 0,05). No se detectaron cambios en los biomarcadores de osteoblastos con 5 días de diferenciación, pero sí con 14 días, registrándose un aumento de Runx2 (p = 0,0008), ColA1 (p = 0,035), OC (p = 0,027) y ALP (sin significancia). Conclusión: estos resultados muestran que el complejo péptido-mineral PHC® estimula la actividad de los osteoblastos maduros, siendo susceptible de promover la formación ósea.

Juglans regia L. extract promotes osteogenesis of human bone marrow mesenchymal stem cells through BMP2/Smad/Runx2 and Wnt/ß-catenin pathways.

BACKGROUND: The present study investigates the effects of Juglans regia L. (walnut, JRL) leaves extract on osteogenesis of human bone marrow mesenchymal stem cells (hBMSCs). METHODS: hBMSCs were incubated with different concentrations of JRL extract (10, 20, 40, or 80 µM). Cell proliferation was evaluated by Cell Counting Kit-8 assay (CCK-8) assay. ALP activity and Alizarin Red staining were used to assess the osteogenesis of BMSCs. Western blot was performed to measure the levels of proteins. RESULTS: Our results showed all concentrations of JRL extract had no significant effect on cell proliferation. JRL extract concentration-dependently promoted osteoblastic differentiation and cell autophagy of hBMSCs, characterized by the increased expression of pro-osteogenic markers alkaline phosphatase (ALP), osteocalcin (BGLAP), osterin, and osteoprotegerin (OPG) and autophagy marker proteins (LC3II, Beclin-1, and p62). Furthermore, JRL extract stimulated the activation BMP2/Smad/Runx2 and Wnt/ß-catenin signaling pathways in hBMSCs, which play key roles in osteogenesis differentiation. Meanwhile, BMP inhibitor (Noggin) and Wnt antagonist Dickkopf-1 (DKK1) both reversed the increases of BGLAP, osterin, and OPG expression induced by JRL extract. CONCLUSIONS: Our findings indicate that JRL extract regulated osteogenic differentiation and cell autophagy of hBMSCs through the BMP2/Smad/Runx2 and Wnt/ß-catenin pathways.

Evaluation of the effects of preconditioned human stem cells plus a scaffold and photobiomodulation administration on stereological parameters and gene expression levels in a critical size bone defect in rats.

We assessed the impact of photobiomodulation (PBM) plus adipose-derived stem cells (ASCs) during the anabolic and catabolic stages of bone healing in a rat model of a critical size femoral defect (CSFD) that was filled with a decellularized bone matrix (DBM). Stereological analysis and gene expression levels of bone morphogenetic protein 4 (BMP4), Runt-related transcription factor 2 (RUNX2), and stromal cell-derived factor 1 (SDF1) were determined. There were six groups of rats. Group 1 was the untreated control or DBM. Study groups 2-6 were treated as follows: ASC (ASC transplanted into DBM, then implanted in the CSFD); PBM (CSFD treated with PBM); irradiated ASC (iASC) (ASCs preconditioned with PBM, then transplanted into DBM, and implanted in the CSFD); ASC + PBM (ASCs transplanted into DBM, then implanted in the CSFD, followed by PBM administration); and iASC + PBM (the same as iASC, except CSFDs were exposed to PBM). At the anabolic step, all treatment groups had significantly increased trabecular bone volume (TBV) (24.22%) and osteoblasts (83.2%) compared to the control group (all, p = .000). However, TBV in group iASC + PBM groups were superior to the other groups (97.48% for osteoblast and 58.8% for trabecular bone volume) (all, p = .000). The numbers of osteocytes in ASC (78.2%) and iASC + PBM (30%) groups were remarkably higher compared to group control (both, p = .000). There were significantly higher SDF (1.5-fold), RUNX2 (1.3-fold), and BMP4 (1.9-fold) mRNA levels in the iASC + PBM group compared to the control and some of the treatment groups. At the catabolic step of bone healing, TBV increased significantly in PBM (30.77%), ASC + PBM (32.27%), and iASC + PBM (35.93%) groups compared to the control group (all, p = .000). There were significantly more osteoblasts and osteocytes in ASC (71.7%, 62.02%) (p = .002, p = .000); PBM (82.54%, 156%), iASC (179%, 23%), and ASC + PBM (108%, 110%) (all, p = .000), and iASC + PBM (79%, 100.6%) (p = .001, p = .000) groups compared to control group. ASC preconditioned with PBM in vitro plus PBM in vivo significantly increased stereological parameters and SDF1, RUNX2, and BMP4 mRNA expressions during bone healing in a CSFD model in rats.

[Effect of Desmodium renifolium on ovariectomized rat model of osteoporosis via BMP-2/Smads signaling pathway].

This study aimed to investigate the effect of Desmodium renifolium(Linn.) Schindl on ovariectomized rat model of osteoporosis and explore the underlying mechanism. Rats were randomized into a sham group, a model group, a Xianlin Gubao group, and low-, medium-, and high-dose D. renifolium groups. Bilateral oophorectomy was performed in other groups except sham group(removal of bilateral peri-ovarian adipose tissue). The sham group and model group were administrated with equal volume of 0.5% CMC-Na, Xianlin Gubao group with Xianlin Gubao, and D. renifolium groups with different concentrations of alcoholic extract of D. renifolium once a day for 14 weeks. The body weight of rats were recorded during the experiment. The levels of estradiol(E_2), 1,25-dihydroxyvitamin D_3 [1,25(OH)_2D_3], calcium(Ca), and phosphorus(P) in serum were determined after the administration. The femur microstructure was analyzed via micro-CT. RT-PCR and Western blot were employed to respectively determine the mRNA and protein levels of bone morphogenetic protein 2(BMP-2), Runt-related transcription factor 2(Runx2), and osterix(OSX) in the tibia of rats. The results indicated that D. renifolium significantly inhibited the weight growth, improved the uterus appearance, elevated the levels of E_2, Ca, P, and 1,25(OH)_2D_3 in serum, increased the number and reduced the fracture of bone trabeculae, ameliorated the bone microstructure parameters, and up-regulated the mRNA and protein levels of BMP-2, Runx2, and OSX. All the results demonstrated that D. renifolium had significant protective effect on the ovariectomized rat model of osteoporosis by regulating the BMP-2/Smads signaling pathway.

Ameliorative effect of allicin on vascular calcification via inhibiting endoplasmic reticulum stress.

OBJECTIVES: Vascular calcification (VC) is an independent predictor for cardiovascular events and mortality. However, there are currently no effective methods to reverse or prevent it. The present study aimed to determine the ameliorative effect of allicin on VC. METHODS: VC model of rats was induced by high-dose vitamin D3, which was valued by Alizarin Red staining, calcium contents, and alkaline phosphatase in the aorta. Systolic blood pressure, pulse pressure, and pulse wave velocity were measured to determine aortic stiffness. Protein levels were detected by Western blot. RESULTS: Allicin treatment rescued aortic VC and stiffness. The increased protein levels of RUNX2 and BMP2, two markers of osteoblastic phenotype of vascular smooth muscle cells, in the calcified aorta were attenuated by allicin, whereas the decreased levels of calponin and SM22α induced by calcification were improved. Allicin treatment significantly attenuated the increased protein levels of GRP78, GRP94, and CHOP, which are key markers of endoplasmic reticulum stress, in the calcified aorta. The activation of PERK/eIF2α/ATF4 cascades was also prevented by allicin. CONCLUSIONS: Allicin could ameliorate aortic VC and stiffness. The ameliorative effect of allicin on VC might be mediated by inhibiting PERK/eIF2α/ATF4 cascades. Our results might provide a new proof for VC treatment.

LncRNA H19 sponges miR-103-3p to promote the high phosphorus-induced osteoblast phenotypic transition of vascular smooth muscle cells by upregulating Runx2.

Elucidating the mechanism of the osteogenic phenotypic transdifferentiation of vascular smooth muscle cells (VSMCs) is the key to determining the diagnosis and treatment of arterial medial calcification (AMC). Long noncoding RNAs (lncRNAs) have been reported to participate in the regulation of vascular physiology and pathology. Here, we investigated the effect and mechanism of the lncRNA H19 on the osteoblastic differentiation of VSMCs induced by high phosphorus. H19 was expressed at high levels in high phosphorus-induced primary rat VSMCs. Further experiments indicated that H19 played a positive role in the osteoblast phenotypic transition by suppressing miR-103-3p expression and subsequently promoting osteoblast-specific marker expression, including bone morphogenetic protein 2 (BMP-2) and osteopontin (OPN). Mechanistically, we recognized RUNX family transcription factor 2 (Runx2) as a direct target of miR-103-3p. Moreover, H19 directly interacted with miR-103-3p, and overexpression of miR-103-3p reversed the upregulation of Runx2 induced by H19. Therefore, H19 positively regulated Runx2 expression by sponging miR-103-3p and promoted the osteoblast phenotypic transition in VSMC calcification. Collectively, the lncRNA H19 promoted osteogenic differentiation by modulating the miR-103-3p/Runx2 axis in the process of VSMC calcification induced by a high phosphorus concentration. The current study provided new insights into an important role for the lncRNA H19 as a miRNA sponge in VSMCs and supplied novel insights into lncRNA-directed diagnostics and therapeutics for vascular calcification.

Resveratrol Ameliorates Aortic Calcification in Ovariectomized Rats via SIRT1 Signaling.

Postmenopausal women are at an increased risk of vascular calcification which is defined as the pathological deposition of minerals in the vasculature, and is strongly linked with increased cardiovascular disease risk. Since estrogen-replacement therapy is associated with increased cancer risk, there is a strong need for safer therapeutic approaches. In this study we aimed to investigate the protective and therapeutic effects of the phytoestrogen resveratrol against vascular calcification in ovariectomized rats, a preclinical model of postmenopause. Furthermore, we aimed to compare the effects of resveratrol to those of estrogen and to explore the mechanisms underpinning those effects. Treatment with resveratrol or estrogen ameliorated aortic calcification in ovariectomized rats, as shown by reduced calcium deposition in the arterial wall. Mechanistically, the effects of resveratrol and estrogen were mediated via the activation of SIRT1 signaling. SIRT1 protein expression was downregulated in the aortas of ovariectomized rats, and upregulated in rats treated with resveratrol or estrogen. Moreover, resveratrol and estrogen reduced the levels of the osteogenic markers: runt-related transcription factor 2 (RUNX2), osteocalcin and alkaline phosphatase (ALP) which have been shown to play a role during vascular calcification. Additionally, the senescence markers (p53, p16 and p21) which were also reported to play a role in the pathogenesis of vascular calcification, were reduced upon treatment with resveratrol and estrogen. In conclusion, the phytoestrogen resveratrol may be a safer alternative to estrogen, as a therapeutic approach against the progression of vascular calcification during postmenopause.