BACKGROUND

Osteogenesis imperfecta (OI) is a group of connective tissue disease characterized by propensity to fractures following minimal trauma. OI is a lifelong inheritable disease and currently has no definitive cure. Management goals are directed towards prevention of fractures, controlling the symptoms, maximizing independent mobility, and developing optimal bone mass and muscle strength. Bisphosphonates are the mainstay of pharmacologic fracture-prevention therapy for most forms of OI. The University of the Philippines-Philippine General Hospital Bisphosphonate Treatment Program for OI was started in 2006 by the Clinical Genetics Service. For more than a decade now, the program has been serving more than 50 OI patients. This study evaluated the clinical outcomes of the patients who were included in the program to add to the body of knowledge on Filipino patients with OI.

This study sought to determine the clinical outcomes of children with OI on intravenous pamidronate treatment at the Philippine General Hospital (PGH) from January 2010 to December 2018.

The study utilized a retrospective review of medical records of 24 patients diagnosed with OI on pamidronate therapy seen at the PGH from January 2010 to December 2018. Descriptive statistics were used to summarize the demographic and baseline clinical characteristics of the patients. Median annualized fracture rates before and during treatment were calculated and compared. The patient functional mobility before and during pamidronate infusion was classified accordingly based on the Gross Motor Function Classification System (GMFCS) and were compared.

Twenty-four patients, which include seven males and 17 females, with ages at the time of conduct of the study ranging from four years to 11 years, fulfilled the inclusion criteria. There were four patients with OI type I, six with OI type III, 11 with OI type IV and three with OI type V. The annualized long bone fracture rate decreased significantly from a median of 2.0/year (range 1-2.75) to 0.75/year (range 0-1) after more than a year on pamidronate infusion (pCONCLUSION

Cyclic intravenous pamidronate treatment in young children with moderate-severe OI is well tolerated and associated with reduced fracture frequency with a tendency to improvement of gross functional mobility.

BACKGROUND: Osteogenesis imperfecta (OI) is a group of connective tissue disease characterized by propensity to fractures following minimal trauma. OI is a lifelong inheritable disease and currently has no definitive cure. Management goals are directed towards prevention of fractures, controlling the symptoms, maximizing independent mobility, and developing optimal bone mass and muscle strength. Bisphosphonates are the mainstay of pharmacologic fracture-prevention therapy for most forms of OI. The University of the Philippines-Philippine General Hospital Bisphosphonate Treatment Program for OI was started in 2006 by the Clinical Genetics Service. For more than a decade now, the program has been serving more than 50 OI patients. This study evaluated the clinical outcomes of the patients who were included in the program to add to the body of knowledge on Filipino patients with OI. OBJECTIVES: This study sought to determine the clinical outcomes of children with OI on intravenous pamidronate treatment at the Philippine General Hospital (PGH) from January 2010 to December 2018. METHODS: The study utilized a retrospective review of medical records of 24 patients diagnosed with OI on pamidronate therapy seen at the PGH from January 2010 to December 2018. Descriptive statistics were used to summarize the demographic and baseline clinical characteristics of the patients. Median annualized fracture rates before and during treatment were calculated and compared. The patient functional mobility before and during pamidronate infusion was classified accordingly based on the Gross Motor Function Classification System (GMFCS) and were compared. RESULTS: Twenty-four patients, which include seven males and 17 females, with ages at the time of conduct of the study ranging from four years to 11 years, fulfilled the inclusion criteria. There were four patients with OI type I, six with OI type III, 11 with OI type IV and three with OI type V. The annualized long bone fracture rate decreased significantly from a median of 2.0/year (range 1-2.75) to 0.75/year (range 0-1) after more than a year on pamidronate infusion (p < 0.001). There is a note of overall improvement in terms of functional mobility using the 5-point scale of the GMFCS during pamidronate infusion from the baseline. However, the difference is not statistically significant. CONCLUSION Cyclic intravenous pamidronate treatment in young children with moderate-severe OI is well tolerated and associated with reduced fracture frequency with a tendency to improvement of gross functional mobility.
Human ; Osteogenesis Imperfecta ; Bisphosphonate ; Diphosphonates

Regenerating periodontal bone defect surrounding periodontal tissue is crucial for orthodontic or dental implant treatment. The declined osteogenic ability of periodontal ligament stem cells (PDLSCs) induced by inflammation stimulus contributes to reduced capacity to regenerate periodontal bone, which brings about a huge challenge for treating periodontitis. Here, inspired by the adhesive property of mussels, we have created adhesive and mineralized hydrogel microspheres loaded with traditional compound cordycepin (MMS-CY). MMS-CY could adhere to the surface of alveolar bone, then promote the migration capacity of PDLSCs and thus recruit them to inflammatory periodontal tissues. Furthermore, MMS-CY rescued the impaired osteogenesis and ligament-forming capacity of PDLSCs, which were suppressed by the inflammation stimulus. Moreover, MMS-CY also displayed the excellent inhibitory effect on the osteoclastic activity. Mechanistically, MMS-CY inhibited the premature senescence induced by the inflammation stimulus through the nuclear factor erythroid 2-related factor (NRF2) pathway and reducing the DNA injury. Utilizing in vivo rat periodontitis model, MMS-CY was demonstrated to enhance the periodontal bone regeneration by improving osteogenesis and inhibiting the osteoclastic activity. Altogether, our study indicated that the multi-pronged approach is promising to promote the periodontal bone regeneration in periodontitis condition by reducing the inflammation-induced stem cell senescence and maintaining bone homeostasis.
Animals ; Bone Regeneration/drug effects* ; Rats ; Periodontal Ligament/cytology* ; Microspheres ; NF-E2-Related Factor 2 ; Hydrogels ; Periodontitis/therapy* ; Osteogenesis/drug effects* ; Disease Models, Animal ; Stem Cells ; Male ; Rats, Sprague-Dawley ; Humans

Dental mesenchymal stem cells (DMSCs) are pivotal for tooth development and periodontal tissue health and play an important role in tissue engineering and regenerative medicine because of their multidirectional differentiation potential and self-renewal ability. The cellular microenvironment regulates the fate of stem cells and can be modified using various optimization techniques. These methods can influence the cellular microenvironment, activate disparate signaling pathways, and induce different biological effects. "Epigenetic regulation" refers to the process of influencing gene expression and regulating cell fate without altering DNA sequences, such as histone methylation. Histone methylation modifications regulate pivotal transcription factors governing DMSCs differentiation into osteo-/odontogenic lineages. The most important sites of histone methylation in tooth organization were found to be H3K4, H3K9, and H3K27. Histone methylation affects gene expression and regulates stem cell differentiation by maintaining a delicate balance between major trimethylation sites, generating distinct chromatin structures associated with specific downstream transcriptional states. Several crucial signaling pathways associated with osteogenic differentiation are susceptible to modulation via histone methylation modifications. A deeper understanding of the regulatory mechanisms governing histone methylation modifications in osteo-/odontogenic differentiation and immune-inflammatory responses of DMSCs will facilitate further investigation of the epigenetic regulation of histone methylation in DMSC-mediated tissue regeneration and inflammation. Here is a concise overview of the pivotal functions of epigenetic histone methylation at H3K4, H3K9, and H3K27 in the regulation of osteo-/odontogenic differentiation and renewal of DMSCs in both non-inflammatory and inflammatory microenvironments. This review summarizes the current research on these processes in the context of tissue regeneration and therapeutic interventions.
Mesenchymal Stem Cells/physiology* ; Humans ; Osteogenesis/genetics* ; Histones/metabolism* ; Cell Differentiation/physiology* ; Methylation ; Odontogenesis/genetics* ; Epigenesis, Genetic

The repair of the periodontal membrane is essential for the successful management of periodontal disease and dental trauma. Emdogain^® (EMD) is widely used in periodontal therapy due to its ability to promote repair. Despite substantial research, the cellular and molecular mechanisms underlying EMD's effects, particularly at the single-cell resolution, remain incompletely understood. This study established a delayed tooth replantation model in rats to investigate these aspects. Tooth loss rate and degree of loosening were evaluated at 4 and 8 weeks. Micro-CT, HE staining, TRAP staining, and immunofluorescence staining were evaluated to assess EMD's efficacy. Single-cell sequencing analyses generated single-cell maps that explored enrichment pathways, cell communication, and potential repair mechanisms. Findings indicated that EMD could reduce the rate of tooth loss, promote periodontal membrane repair, and reduce root and bone resorption. Single-cell analysis revealed that EMD promotes the importance of Vtn+ fibroblasts, enhancing matrix and tissue regeneration functions. Additionally, EMD stimulated osteogenic pathways, reduced osteoclastic activity, and promoted angiogenesis-related pathways, particularly bone-related H-type vessel expression in endothelial cells. Gene modules associated with angiogenesis, osteogenesis, and odontoblast differentiation were identified, suggesting EMD might facilitate osteogenesis and odontoblast differentiation by upregulating endothelium-related genes. Immune cell analysis indicated that EMD did not elicit a significant immune response. Cell communication analysis suggested that EMD fostered pro-regenerative networks driven by interactions between mesenchymal stem cells, fibroblasts, and endothelial cells. In conclusion, EMD proves to be an effective root surface therapy agent that supports the restoration of delayed replantation teeth.
Animals ; Tooth Replantation/methods* ; Rats ; Dental Enamel Proteins/pharmacology* ; Single-Cell Analysis ; Rats, Sprague-Dawley ; X-Ray Microtomography ; Osteogenesis/drug effects* ; Male ; Periodontal Ligament/drug effects*

Insufficient alveolar bone thickness increases the risk of periodontal dehiscence and fenestration, especially in orthodontic tooth movement. Abaloparatide (ABL), a synthetic analog of human PTHrP (1-34) and a clinical medication for treating osteoporosis, has recently demonstrated its potential in enhancing craniofacial bone formation. Herein, we show that intraoral submucosal injection of ABL, when combined with mechanical force, promotes in situ alveolar bone thickening. The newly formed bone is primarily located outside the original compact bone, implying its origin from the periosteum. RNA sequencing of the alveolar bone tissue revealed that the focal adhesion (FA) pathway potentially mediates this bioprocess. Local injection of ABL alone enhances cell proliferation, collagen synthesis, and phosphorylation of focal adhesion kinase (FAK) in the alveolar periosteum; when ABL is combined with mechanical force, the FAK expression is upregulated, in line with the accomplishment of the ossification. In vitro, ABL enhances proliferation, migration, and FAK phosphorylation in periosteal stem cells. Furthermore, the pro-osteogenic effects of ABL on alveolar bone are entirely blocked when FAK activity is inhibited by a specific inhibitor. In summary, abaloparatide combined with mechanical force promotes alveolar bone formation via FAK-mediated periosteal osteogenesis. Thus, we have introduced a promising therapeutic approach for drug-induced in situ alveolar bone augmentation, which may prevent or repair the detrimental periodontal dehiscence, holding significant potential in dentistry.
Osteogenesis/drug effects* ; Periosteum/cytology* ; Parathyroid Hormone-Related Protein/administration & dosage* ; Animals ; Focal Adhesion Protein-Tyrosine Kinases/metabolism* ; Alveolar Process/drug effects* ; Cell Proliferation/drug effects* ; Phosphorylation ; Rats ; Male ; Humans ; Focal Adhesion Kinase 1/metabolism* ; Cell Movement/drug effects*

The mandibular condyle is a critical growth center in craniofacial bone development, especially during postnatal stages. Postnatal condyle osteogenesis requires precise spatiotemporal coordination of growth factor signaling cascades and hierarchical gene regulatory networks. Plagl1, which encodes a zinc finger transcription factor, is a paternally expressed gene. We demonstrate that PLAGL1 is highly expressed in cranial neural crest cell (CNCC)-derived lineage cells in mouse condyles. Using the CNCC-derived lineage-specific Plagl1 knockout mouse model, we evaluate the function of PLAGL1 during postnatal mouse condyle development. Our findings show that PLAGL1 contributes significantly to osteoblast differentiation, and its deficiency impairs osteogenic lineage differentiation, which consequently disrupts mandibular condyle development. Mechanistically, insulin-like growth factor 2 (IGF2) in complex with IGF-binding proteins (IGFBPs) has been identified as the principal PLAGL1 effector responsible for osteogenic regulation during postnatal condyle morphogenesis. Plagl1 deficiency significantly downregulates the IGF2/IGFBP pathway, leading to disordered glucose metabolism, defective extracellular matrix organization, and impaired ossification. Exogenous IGF2 treatment rescues impaired osteoblast differentiation caused by Plagl1 deficiency. In conclusion, the PLAGL1-IGF2 axis is a critical regulator of osteogenesis during mandibular condyle development.
Animals ; Osteogenesis/genetics* ; Insulin-Like Growth Factor II/metabolism* ; Mice ; Transcription Factors/metabolism* ; Mice, Knockout ; Cell Differentiation ; DNA-Binding Proteins/genetics* ; Mandibular Condyle/growth & development* ; Osteoblasts/cytology* ; Signal Transduction ; Neural Crest/cytology*

Osteoporosis(OP) is a senile bone disease characterized by an imbalance between bone remodeling and bone formation. Targeting pathogenesis of kidney deficiency, spleen deficiency, and blood stasis, Bushen Jianpi Huoxue Decoction has a significant effect on the treatment of OP by tonifying kidney, invigorating spleen, and activating blood circulation. MicroRNA(miRNA) and the anti-apoptotic protein B-cell lymphoma-2-like protein 1(BCL2L1) are closely related to bone cell metabolism. Therefore, in this study, the binding of miR-140-5p to BCL2L1 was detected by dual luciferase assay and polymerase chain reaction(PCR). After silencing or overexpressing miR-140-5p, the apoptosis, autophagy, and osteogenic function of human fetal osteoblast cell line 1.19(HFOB1.19) were observed by flow cytometry and Western blot. Bushen Jianpi Huoxue Decoction-containing serum was prepared by intragastric administration of Bushen Jianpi Huoxue Decoction in rats. Different concentrations of Bushen Jianpi Huoxue Decoction-containing serum were used to treat HFOB1.19 with or without miR-140-5p mimic. The expression of osteogenic proteins in each group was observed, and the role of miR-140-5p/BCL2L1 in apoptosis and autophagy of HFOB1.19 was studied, along with the effect of Bushen Jianpi Huoxue Decoction on these processes. As indicated by the dual luciferase assay, miR-140-5p bound to BCL2L1. Flow cytometry and Western blot showed that miR-140-5p promoted apoptosis and inhibited autophagy in HFOB1.19. After intervention with high, medium, and low doses of Bushen Jianpi Huoxue Decoction-medicated serum, compared with the miR-140-5p NC group, the expression of osteocalcin(OCN), osteopontin(OPN), Runt-related transcription factor 2(RUNX2), and transforming growth factor beta 1(TGF-β1) decreased in the miR-140-5p mimic group, while the expression of bone morphogenetic protein 2(BMP2) showed no significant difference under high-dose intervention. Therefore, miR-140-5p/BCL2L1 can promote apoptosis and inhibit autophagy in HFOB1.19. Bushen Jianpi Huoxue Decoction can affect the osteogenic effect of miR-140-5p through BMP2.
MicroRNAs/metabolism* ; Autophagy/drug effects* ; Apoptosis/drug effects* ; Humans ; Drugs, Chinese Herbal/administration & dosage* ; Animals ; Cell Line ; bcl-X Protein/metabolism* ; Osteoblasts/metabolism* ; Rats ; Osteoporosis/physiopathology* ; Male ; Rats, Sprague-Dawley ; Osteogenesis/drug effects*

This study investigated the mechanism of autophagy in the differentiation processes of MC3T3-E1 cells under osteogenic induction(physiological) and alcohol(AL) intervention(pathological), as well as the mechanism by which icariin(ICA) affected osteogenic differentiation of MC3T3-E1 cells under the pathological condition of AL intervention. Osteogenic mineralized nodule staining confirmed that the cells could differentiate into osteoblasts. After determining the appropriate concentrations of AL and ICA using the CCK-8 assay, seven groups were set up in this study: complete medium(CM) group, osteogenic induction medium(OIM) group, OIM+0.25 mol·L~(-1) AL group, OIM+0.25 mol·L~(-1) AL+1×10~(-8) mol·L~(-1) ICA group, OIM+0.25 mol·L~(-1) AL+1×10~(-7) mol·L~(-1) ICA group, OIM+0.25 mol·L~(-1) AL+1×10~(-6) mol·L~(-1) ICA group, and OIM+0.25 mol·L~(-1) AL+1×10~(-5) mol·L~(-1) ICA group, with a culture period of 7 days. Alkaline phosphatase(ALP) staining was used to detect the relative ALP area. Western blot and RT-qPCR were employed to analyze the expression of osteogenesis-and autophagy-related proteins and mRNAs. Reactive oxygen species(ROS) staining was used to detect ROS levels, and apoptosis was assessed through mitochondrial membrane potential assays. The results showed that ICA increased the relative ALP area that had been reduced by AL intervention. AL down-regulated the expression levels of Wnt family member 1(Wnt1), along with the osteogenesis-related mRNAs Wnt1, β-catenin, Runt-related transcription factor 2(Runx2), osteoprotegerin(OPG), and ALP, thereby inhibiting osteogenic differentiation. ICA up-regulated the expression levels of the osteogenesis-related proteins and mRNAs that had been inhibited by AL, promoting osteogenic differentiation. AL inhibited typical autophagy, while ICA regulated Rubicon to suppress LC3-associated phagocytosis(LAP) and promote typical autophagy. ICA also reduced the ROS levels that were elevated by AL and decreased the apoptosis of osteoblasts induced by AL intervention. In conclusion, ICA can regulate Rubicon to inhibit LAP, promote typical autophagy, eliminate ROS, reduce apoptosis, and ultimately enhance the osteogenic differentiation of MC3T3-E1 cells under the pathological condition of AL intervention by modulating the Wnt/β-catenin signaling pathway.
Autophagy/drug effects* ; Animals ; Osteogenesis/drug effects* ; Mice ; Cell Differentiation/drug effects* ; Osteoblasts/metabolism* ; Ethanol/pharmacology* ; Flavonoids/pharmacology* ; Cell Line ; Reactive Oxygen Species/metabolism* ; Drugs, Chinese Herbal/pharmacology*

Guided by the theory of "the kidney storing essence, governing the bones, and producing marrow", this study explored the mechanism of icariin(ICA) in regulating the osteogenic differentiation of rat bone mesenchymal stem cells(BMSCs) through caveolin-1(Cav1) via in vitro and in vivo experiments, aiming to provide a theoretical basis for the prevention and treatment of postmenopausal osteoporosis with traditional Chinese medicine(TCM). Primary cells were obtained from 4-week-old female SD rats using the whole bone marrow adherent method. Flow cytometry was used to detect the expression of surface markers CD29, CD90, CD11b, and CD45. The potential for osteogenic and adipogenic differentiation was assessed. The effect of ICA on cell viability was determined using the CCK-8 assay, and the impact of ICA on the formation of mineralized nodules was verified by alizarin red staining. A stable Cav1-silenced cell line was constructed using lentivirus. The effect of Cav1 silencing on osteogenic differentiation was observed via alizarin red staining. Western blot analysis was conducted to detect the expression of Cav1, Hippo/TAZ, and osteogenic markers such as Runt-related transcription factor 2(RUNX2) and alkaline phosphatase(ALP). The results showed that primary cells were successfully obtained using the whole bone marrow adherent method, positively expressing surface markers of rat BMSCs and possessing the potential for both osteogenic and adipogenic differentiation. The CCK-8 assay and alizarin red staining results indicated that 1×10~(-7) mol·L~(-1) was the optimal concentration of ICA for intervention in this experiment(P<0.05). During osteogenic induction, ICA inhibited Cav1 expression(P<0.05) while promoting TAZ expression(P<0.05). Alizarin red staining demonstrated that Cav1 silencing significantly promoted the osteogenic differentiation of BMSCs. After ICA intervention, TAZ expression was activated, and the expression of osteogenic markers ALP and RUNX2 was increased. In conclusion, Cav1 silencing significantly promotes the osteogenic differentiation of BMSCs, and ICA promotes this differentiation by inhibiting Cav1 and regulating the Hippo/TAZ signaling pathway.
Animals ; Mesenchymal Stem Cells/metabolism* ; Caveolin 1/genetics* ; Osteogenesis/drug effects* ; Rats, Sprague-Dawley ; Rats ; Cell Differentiation/drug effects* ; Female ; Signal Transduction/drug effects* ; Flavonoids/administration & dosage* ; Protein Serine-Threonine Kinases/genetics* ; Drugs, Chinese Herbal/pharmacology* ; Cells, Cultured ; Humans