As a member of the AFF (AF4/FMR2) family, AFF4 is a transcription elongation factor that is a component of the super elongation complex. AFF4 serves as a scaffolding protein that connects transcription factors and promotes gene transcription through elongation and chromatin remodelling. Here, we investigated the effect of AFF4 on human dental follicle cells (DFCs) in osteogenic differentiation. In this study, we found that small interfering RNA-mediated depletion of AFF4 resulted in decreased alkaline phosphatase (ALP) activity and impaired mineralization. In addition, the expression of osteogenic-related genes (DLX5, SP7, RUNX2 and BGLAP) was significantly downregulated. In contrast, lentivirus-mediated overexpression of AFF4 significantly enhanced the osteogenic potential of human DFCs. Mechanistically, we found that both the mRNA and protein levels of ALKBH1, a critical regulator of epigenetics, changed in accordance with AFF4 expression levels. Overexpression of ALKBH1 in AFF4-depleted DFCs partially rescued the impairment of osteogenic differentiation. Our data indicated that AFF4 promoted the osteogenic differentiation of DFCs by upregulating the transcription of ALKBH1.
Biomarkers ; metabolism ; Cell Differentiation ; Cells, Cultured ; Dental Sac ; drug effects ; metabolism ; Gene Expression Regulation ; Humans ; Osteogenesis ; genetics ; Repressor Proteins ; Transcription Factors ; genetics ; metabolism ; Transcriptional Elongation Factors ; metabolism

Once pulp necrosis or apical periodontitis occurs on immature teeth, the weak root and open root apex are challenging to clinicians. Berberine (BBR) is a potential medicine for bone disorders, therefore, we proposed to apply BBR in root canals to enhance root repair in immature teeth. An in vivo model of immature teeth with apical periodontitis was established in rats, and root canals were filled with BBR, calcium hydroxide or sterilized saline for 3 weeks. The shape of the roots was analyzed by micro-computed tomography and histological staining. In vitro, BBR was introduced into stem cells from apical papilla (SCAPs). Osteogenic differentiation of stem cells from apical papilla was investigated by alkaline phosphatase activity, mineralization ability, and gene expression of osteogenic makers. The signaling pathway, which regulated the osteogenesis of SCAPs was evaluated by quantitative real time PCR, Western blot analysis, and immunofluorescence. In rats treated with BBR, more tissue was formed, with longer roots, thicker root walls, and smaller apex diameters. In addition, we found that BBR promoted SCAPs osteogenesis in a time-dependent and concentration-dependent manner. BBR induced the expression of β-catenin and enhanced β-catenin entering into the nucleus, to up-regulate more runt-related nuclear factor 2 downstream. BBR enhanced root repair in immature teeth with apical periodontitis by activating the canonical Wnt/β-catenin pathway in SCAPs.
Animals ; Berberine ; pharmacology ; Cell Differentiation ; drug effects ; Dental Papilla ; Male ; Osteogenesis ; drug effects ; Periapical Periodontitis ; therapy ; Rats ; Stem Cells ; cytology ; drug effects ; metabolism ; Wnt Signaling Pathway ; drug effects ; Wnt3A Protein ; genetics ; metabolism ; X-Ray Microtomography

Efforts to control inflammation and achieve better tissue repair in the treatment of periodontitis have been ongoing for years. Human β-defensin 3, a broad-spectrum antimicrobial peptide has been proven to have a variety of biological functions in periodontitis; however, relatively few reports have addressed the effects of human periodontal ligament cells (hPDLCs) on osteogenic differentiation. In this study, we evaluated the osteogenic effects of hPDLCs with an adenoviral vector encoding human β-defensin 3 in an inflammatory microenvironment. Then human β-defensin 3 gene-modified rat periodontal ligament cells were transplanted into rats with experimental periodontitis to observe their effects on periodontal bone repair. We found that the human β-defensin 3 gene-modified hPDLCs presented with high levels of osteogenesis-related gene expression and calcium deposition. Furthermore, the p38 MAPK pathway was activated in this process. In vivo, human β-defensin 3 gene-transfected rat PDLCs promoted bone repair in SD rats with periodontitis, and the p38 mitogen-activated protein kinase (MAPK) pathway might also have been involved. These findings demonstrate that human β-defensin 3 accelerates osteogenesis and that human β-defensin 3 gene modification may offer a potential approach to promote bone repair in patients with periodontitis.
Animals ; Anti-Infective Agents ; metabolism ; pharmacology ; Cell Differentiation ; drug effects ; Cells, Cultured ; Humans ; Osteogenesis ; drug effects ; Periodontal Ligament ; drug effects ; metabolism ; Periodontitis ; drug therapy ; Rats ; Rats, Sprague-Dawley ; beta-Defensins ; metabolism ; pharmacology

OBJECTIVE: To investigate the effects of autophagy on osteogenic differentiation of stem cells from the apical papilla (SCAPs) in the presence of tumor necrosis factor- (TNF-) stimulation . METHODS: SCAPs treated with TNF- (0, 5, and 10 ng/mL) with or without 5 mmol/L 3-MA were examined for the expression of autophagy marker LC3-Ⅱ using Western blotting. The cells were transfected with GFP-LC3 plasmid and fluorescence microscopy was used for quantitative analysis of intracellular GFP-LC3; AO staining was used to detect the acidic vesicles in the cells. The cell viability was assessed with CCK-8 assays and the cell apoptosis rate was analyzed using flow cytometry. The cells treated with TNF- or with TNF- and 3-MA were cultured in osteogenic differentiation medium for 3 to 14 days, and real- time PCR was used to detect the mRNA expressions of osteogenesis-related genes (ALP, BSP, and OCN) for evaluating the cell differentiation. RESULTS: TNF- induced activation of autophagy in cultured SCAPs. Pharmacological inhibition of TNF--induced autophagy by 3-MA significantly decreased the cell viability and increased the apoptosis rate of SCAPs ( < 0.05). Compared with the cells treated with TNF- alone, the cells treated with both TNF- and 3-MA exhibited decreased expressions of the ALP and BSP mRNA on days 3, 7 and 14 during osteogenic induction ( < 0.05) and decreased expression of OCN mRNA on days 3 and 7 during the induction ( < 0.05). CONCLUSIONS Autophagy may play an important role during the osteogenic differentiation of SCAPs in the presence of TNF- stimulation.
Autophagy ; drug effects ; physiology ; Cell Differentiation ; drug effects ; physiology ; Cell Survival ; drug effects ; Cells, Cultured ; Dental Papilla ; cytology ; Green Fluorescent Proteins ; Humans ; Osteogenesis ; physiology ; Stem Cells ; drug effects ; physiology ; Transfection ; Tumor Necrosis Factor-alpha ; administration & dosage ; antagonists & inhibitors ; pharmacology

Genetic studies have revealed a critical role of Distal-homeobox (Dlx) genes in bone formation, and our previous study showed that Dlx2 overexpressing in neural crest cells leads to profound abnormalities of the craniofacial tissues. The aim of this study was to investigate the role and the underlying molecular mechanisms of Dlx2 in osteogenic differentiation of mouse bone marrow stromal cells (BMSCs) and pre-osteoblast MC3T3-E1 cells. Initially, we observed upregulation of Dlx2 during the early osteogenesis in BMSCs and MC3T3-E1 cells. Moreover, Dlx2 overexpression enhanced alkaline phosphatase (ALP) activity and extracellular matrix mineralization in BMSCs and MC3T3-E1 cell line. In addition, micro-CT of implanted tissues in nude mice confirmed that Dlx2 overexpression in BMSCs promoted bone formation in vivo. Unexpectedly, Dlx2 overexpression had little impact on the expression level of the pivotal osteogenic transcription factors Runx2, Dlx5, Msx2, and Osterix, but led to upregulation of Alp and Osteocalcin (OCN), both of which play critical roles in promoting osteoblast maturation. Importantly, luciferase analysis showed that Dlx2 overexpression stimulated both OCN and Alp promoter activity. Through chromatin-immunoprecipitation assay and site-directed mutagenesis analysis, we provide molecular evidence that Dlx2 transactivates OCN and Alp expression by directly binding to the Dlx2-response cis-acting elements in the promoter of the two genes. Based on these findings, we demonstrate that Dlx2 overexpression enhances osteogenic differentiation in vitro and accelerates bone formation in vivo via direct upregulation of the OCN and Alp gene, suggesting that Dlx2 plays a crucial role in osteogenic differentiation and bone formation.
Animals ; Cell Differentiation ; physiology ; Core Binding Factor Alpha 1 Subunit ; Homeodomain Proteins ; metabolism ; Mesenchymal Stem Cells ; metabolism ; Mice ; Mice, Nude ; Osteoblasts ; metabolism ; Osteocalcin ; drug effects ; Osteogenesis ; physiology ; Transcription Factors ; metabolism ; Up-Regulation

The Hedgehog (Hh) signalling pathway is essential for cellular proliferation and differentiation during embryonic development. Gain and loss of function of Hh signalling are known to result in an array of craniofacial malformations. To determine the critical period for Hh pathway antagonist-induced frontal bone hypoplasia, we examined patterns of dysmorphology caused by Hh signalling inhibition. Pregnant mice received a single oral administration of Hh signalling inhibitor GDC-0449 at 100 mg•kg or 150 mg•kg body weight at preselected time points between embryonic days (E)8.5 and 12.5. The optimal teratogenic concentration of GDC-0449 was determined to be 150 mg•kg. Exposure between E9.5 and E10.5 induced frontal bone dysplasia, micrognathia and limb defects, with administration at E10.5 producing the most pronounced effects. This model showed decreased ossification of the frontal bone with downregulation of Hh signalling. The osteoid thickness of the frontal bone was significantly reduced. The amount of neural crest-derived frontal bone primordium was reduced after GDC-0449 exposure owing to a decreased rate of cell proliferation and increased cell death.
Administration, Oral ; Anilides ; pharmacology ; Animals ; Bone Diseases, Developmental ; chemically induced ; Cell Proliferation ; drug effects ; physiology ; Female ; Frontal Bone ; abnormalities ; Hedgehog Proteins ; antagonists & inhibitors ; Limb Deformities, Congenital ; chemically induced ; Mice ; Micrognathism ; chemically induced ; Osteogenesis ; drug effects ; Pregnancy ; Pyridines ; pharmacology ; Signal Transduction ; drug effects

OBJECTIVE: This study aims to evaluate the effect of Angelica sinensis polysaccharide (ASP) on the osteogenic differentiation of the bone marrow mesenchymal stem cells (BMSCs) of rats with high glucose levels. METHODS: Rat BMSCs were isolated and identified by osteogenic and adipogenic differentiation. Then, the BMSCs were divided into three groups as follows: normal control group (5.5 mmol·L⁻¹ glucose), high glucose group (25.5 mmol·L⁻¹ glucose), and ASP+high glucose group (25.5 mmol·L⁻¹ glucose +40 mg·L⁻¹ ASP). The proliferation activities of the BMSCs were detected by CCK8. Alizarin red staining, and alkaline phosphatase activity were used in the examination of osteogenic activity. Quantitative real time-polymerase chain reaction was used to detect the expression levels of the osteogenic genes (Runx2, Osx, OCN, Col-Ⅰ) and the key factors of Wnt/β-catenin signal pathway (CyclinD1, β-catenin). In vivo, a type 2 diabetes rat model was established. The rats were divided into three groups, namely, the normal control group (normal rats), diabetes group (diabetic rats), diabetes+ASP group (diabetic rats, ASP feeding). Then, the tibia bone defect was established. The repair of bone defects in each group was observed through histological examination. RESULTS: The proliferation of BMSCs was higher in the high glucose group and ASP+high glucose group than in the normal control group (P<0.05). No significant difference was observed between the high glucose group and ASP+high glucose group (P>0.05). The number of calcium nodules of BMSCs; alkaline phosphatase activity; and the mRNA expression of Runx2, OCN, Osx, Col-Ⅰ, CyclinD1, β-catenin in the high glucose group were lower than those in the normal control and ASP+high glucose groups (P<0.05). No significant difference was observed between the normal control and ASP+high glucose groups (P>0.05). The bone mass was significantly lower in the bone defect of the diabetes group than in the bone defect of the normal control or diabetes+ASP group (P<0.05). No statistical difference was found between the normal control and diabetes+ASP groups (P>0.05). CONCLUSIONS ASP can promote the osteogenic differentiation of rat BMSCs under high glucose culture and induce bone regeneration in rats with type 2 diabetes. These features may be related to the activation of the Wnt/β-catenin signaling pathway.
Angelica sinensis ; chemistry ; Animals ; Bone Marrow Cells ; Cell Differentiation ; drug effects ; Cells, Cultured ; Diabetes Mellitus, Experimental ; Diabetes Mellitus, Type 2 ; Glucose ; Mesenchymal Stem Cells ; Osteogenesis ; drug effects ; Plant Extracts ; pharmacology ; Polysaccharides ; pharmacology ; Rats

OBJECTIVES: To reassess the safety and efficacy of once-weekly teriparatide 56.5 mg in osteoporosis patients with a high fracture risk. METHODS: This postmarketing observational study was conducted at 72 weeks according to the package insert. Of the 3573 Japanese osteoporosis patients in the safety analysis set, 91.80% were women, the mean age was 78.1 years, and 69.89% had a history of prevalent fragility fractures, indicating that a high proportion of patients at high risk of fracture were enrolled. RESULTS: Persistence with weekly teriparatide treatment was 59.36%, and 38.95% at 24 and 72 weeks, respectively. Adverse drug reactions (ADRs) were reported in 898 patients (25.13%), and serious ADRs were reported in 26 patients (0.73%). The most frequent ADRs were nausea, vomiting, and headache. The cumulative incidence of new vertebral fractures 72 weeks after the start of treatment was 3.31%. Increases in the bone mineral density were observed in the lumbar spine, femoral neck, and proximal femur. The serum levels of the bone formation markers, procollagen type I N-terminal propeptide and bone-type alkaline phosphatase, increased slightly at 24 weeks and then decreased to baseline levels. At 24 and 72 weeks, the bone resorption markers, serum cross-linked N-terminal telopeptide of type I collagen and urinary cross-linked N-terminal telopeptide of type I collagen, were the same as or slightly lower than at baseline. Visual analogue scale scores for low back pain also decreased. CONCLUSIONS: The present results showed that once-weekly teriparatide may also be useful for osteoporosis patients with a high risk of fracture.
Alkaline Phosphatase ; Asian Continental Ancestry Group ; Biomarkers ; Bone Density ; Bone Resorption ; Collagen Type I ; Drug-Related Side Effects and Adverse Reactions ; Female ; Femur ; Femur Neck ; Headache ; Humans ; Incidence ; Low Back Pain ; Nausea ; Observational Study ; Osteogenesis ; Osteoporosis ; Product Labeling ; Spine ; Teriparatide ; Vomiting

Bone formation is important for the reconstruction of bone-related structures in areas that have been damaged by inflammation. Inflammatory conditions such as those that occur in patients with rheumatoid arthritis, cystic fibrosis, and periodontitis have been shown to inhibit osteoblastic differentiation. This study focussed on dental follicle stem cells (DFSCs), which are found in developing tooth germ and participate in the reconstruction of alveolar bone and periodontal tissue in periodontal disease. After bacterial infection of inflamed dental tissue, the destruction of bone was observed. Currently, little is known about the relationship between the inflammatory environment and bone formation. Osteogenic differentiation of inflamed DFSCs resulted in decreased alkaline phosphatase (ALP) activity and alizarin red S staining compared to normal DFSCs. Additionally, in vivo transplantation of inflamed and normal DFSCs demonstrated severe impairment of osteogenesis by inflamed DFSCs. Protein profile analysis via liquid chromatography coupled with tandem mass spectrometry was performed to analyse the differences in protein expression in inflamed and normal tissue. Comparison of inflamed and normal DFSCs showed significant changes in the level of expression of transforming growth factor (TGF)-β2. Porphyromonas gingivalis (P.g.)-derived lipopolysaccharide (LPS) was used to create in vitro inflammatory conditions similar to periodontitis. The osteogenic differentiation of LPS-treated DFSCs was suppressed, and the cells displayed low levels of TGF-β1 and high levels of TGF-β2. DFSCs treated with TGF-β2 inhibitors showed significant increases in alizarin red S staining and ALP activity. TGF-β1 expression was also increased after inhibition of TGF-β2. By examining inflamed DFSCs and LPS-triggered DFSCs, these studies showed both clinically and experimentally that the increase in TGF-β2 levels that occurs under inflammatory conditions inhibits bone formation.
Adolescent ; Alkaline Phosphatase ; metabolism ; Animals ; Cell Differentiation ; Cell Proliferation ; Cell Survival ; Cells, Cultured ; Dental Sac ; cytology ; metabolism ; Down-Regulation ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Immunohistochemistry ; Male ; Mass Spectrometry ; Mice ; Nitric Oxide ; metabolism ; Osteogenesis ; drug effects ; Polymerase Chain Reaction ; Staining and Labeling ; Stem Cells ; cytology ; metabolism ; Transforming Growth Factor beta2 ; pharmacology ; Young Adult

Bone wound healing is a highly dynamic and precisely controlled process through which damaged bone undergoes repair and complete regeneration. External factors can alter this process, leading to delayed or failed bone wound healing. The findings of recent studies suggest that the use of selective serotonin reuptake inhibitors (SSRIs) can reduce bone mass, precipitate osteoporotic fractures and increase the rate of dental implant failure. With 10% of Americans prescribed antidepressants, the potential of SSRIs to impair bone healing may adversely affect millions of patients' ability to heal after sustaining trauma. Here, we investigate the effect of the SSRI sertraline on bone healing through pre-treatment with (10 mg·kg sertraline in drinking water, n = 26) or without (control, n = 30) SSRI followed by the creation of a 5-mm calvarial defect. Animals were randomized into three surgical groups: (a) empty/sham, (b) implanted with a DermaMatrix scaffold soak-loaded with sterile PBS or (c) DermaMatrix soak-loaded with 542.5 ng BMP2. SSRI exposure continued until sacrifice in the exposed groups at 4 weeks after surgery. Sertraline exposure resulted in decreased bone healing with significant decreases in trabecular thickness, trabecular number and osteoclast dysfunction while significantly increasing mature collagen fiber formation. These findings indicate that sertraline exposure can impair bone wound healing through disruption of bone repair and regeneration while promoting or defaulting to scar formation within the defect site.
Animals ; Apoptosis ; Bone Morphogenetic Protein 2 ; Cell Culture Techniques ; Cell Proliferation ; Enzyme-Linked Immunosorbent Assay ; Immunohistochemistry ; Male ; Mice ; Mice, Inbred C57BL ; Osteogenesis ; drug effects ; Random Allocation ; Real-Time Polymerase Chain Reaction ; Serotonin Uptake Inhibitors ; adverse effects ; pharmacology ; Sertraline ; adverse effects ; pharmacology ; Skull ; diagnostic imaging ; drug effects ; injuries ; Wound Healing ; drug effects ; X-Ray Microtomography