As the major cell precursors in osteogenesis, mesenchymal stem cells(MSCs) are indispensable for bone homeostasis and development. However, the primary mechanisms regulating osteogenic differentiation are controversia...As the major cell precursors in osteogenesis, mesenchymal stem cells(MSCs) are indispensable for bone homeostasis and development. However, the primary mechanisms regulating osteogenic differentiation are controversial. Composed of multiple constituent enhancers, super enhancers(SEs) are powerful cis-regulatory elements that identify genes that ensure sequential differentiation. The present study demonstrated that SEs were indispensable for MSC osteogenesis and involved in osteoporosis development. Through integrated analysis, we identified the most common SE-targeted and osteoporosis-related osteogenic gene,ZBTB16. ZBTB16, positively regulated by SEs, promoted MSC osteogenesis but was expressed at lower levels in osteoporosis.Mechanistically, SEs recruited bromodomain containing 4(BRD4) at the site of ZBTB16, which then bound to RNA polymerase IIassociated protein 2(RPAP2) that transported RNA polymerase Ⅱ(POL Ⅱ) into the nucleus. The subsequent synergistic regulation of POL Ⅱ carboxyterminal domain(CTD) phosphorylation by BRD4 and RPAP2 initiated ZBTB16 transcriptional elongation, which facilitated MSC osteogenesis via the key osteogenic transcription factor SP7. Bone-targeting ZBTB16 overexpression had a therapeutic effect on the decreased bone density and remodeling capacity of Brd4^(fl/fl)Prx1-cre mice and osteoporosis(OP) models.Therefore, our study shows that SEs orchestrate the osteogenesis of MSCs by targeting ZBTB16 expression, which provides an attractive focus and therapeutic target for osteoporosis.展开更多
Magnesium(Mg) and its alloys have been intensively studied to develop the next generation of bone implants recently, but their clinical application is restricted by rapid degradation and unsatisfied osteogenic effect ...Magnesium(Mg) and its alloys have been intensively studied to develop the next generation of bone implants recently, but their clinical application is restricted by rapid degradation and unsatisfied osteogenic effect in vivo. A bioactive chemical conversion Mg-phenolic networks complex coating(e EGCG) was stepwise incorporated by epigallocatechin-3-gallate(EGCG) and exogenous Mg^(2+)on Mg-2Zn magnesium alloy. Simplex EGCG induced chemical conversion coating(c EGCG) was set as compare group. The in vitro corrosion behavior of Mg-2Zn alloy, c EGCG and e EGCG was evaluated in SBF using electrochemical(PDP, EIS) and immersion test. The cytocompatibility was investigated with rat bone marrow mesenchymal stem cells(r BMSCs). Furthermore, the in vivo tests using a rabbit model involved micro computed tomography(Micro-CT) analysis, histological observation, and interface analysis. The results showed that the e EGCG is Mgphenolic multilayer coating incorporated Mg-phenolic networks, which is rougher, more compact and much thicker than c EGCG. The e EGCG highly improved the corrosion resistance of Mg-2Zn alloy, combined with its lower average hemolytic ratios, continuous high scavenging effect ability and relatively moderate contact angle features, resulting in a stable and suitable biological environment, obviously promoted r BMSCs adhesion and proliferation. More importantly, Micro-CT, histological and interface elements distribution evaluations all revealed that the e EGCG effectively inhibited degradation and enhanced bone tissue formation of Mg alloy implants. This study puts forward a promising bioactive chemical conversion coating with Mg-phenolic networks for the application of biodegradable orthopedic implants.展开更多
Osteogenesis imperfecta(OI)is a genetically heterogeneous monogenic disease characterized by decreased bone mass,bone fragility,and recurrent fractures.The phenotypic spectrum varies considerably ranging from prenatal...Osteogenesis imperfecta(OI)is a genetically heterogeneous monogenic disease characterized by decreased bone mass,bone fragility,and recurrent fractures.The phenotypic spectrum varies considerably ranging from prenatal fractures with lethal outcomes to mild forms with few fractures and normal stature.The basic mechanism is a collagen-related defect,not only in synthesis but also in folding,processing,bone mineralization,or osteoblast function.In recent years,great progress has been made in identifying new genes and molecular mechanisms underlying OI.In this context,the classification of OI has been revised several times and different types are used.The Sillence classification,based on clinical and radiological characteristics,is currently used as a grading of clinical severity.Based on the metabolic pathway,the functional classification allows identifying regulatory elements and targeting specific therapeutic approaches.Genetic classification has the advantage of identifying the inheritance pattern,an essential element for genetic counseling and prophylaxis.Although genotype-phenotype correlations may sometimes be challenging,genetic diagnosis allows a personalized management strategy,accurate family planning,and pregnancy management decisions including options for mode of delivery,or early antenatal OI treatment.Future research on molecular pathways and pathogenic variants involved could lead to the development of genotype-based therapeutic approaches.This narrative review summarizes our current understanding of genes,molecular mechanisms involved in OI,classifications,and their utility in prophylaxis.展开更多
Objective Osteogenesis is vitally important for bone defect repair,and Zuo Gui Wan(ZGW)is a classic prescription in traditional Chinese medicine(TCM)for strengthening bones.However,the specific mechanism by which ZGW ...Objective Osteogenesis is vitally important for bone defect repair,and Zuo Gui Wan(ZGW)is a classic prescription in traditional Chinese medicine(TCM)for strengthening bones.However,the specific mechanism by which ZGW regulates osteogenesis is still unclear.The current study is based on a network pharmacology analysis to explore the potential mechanism of ZGW in promoting osteogenesis.Methods A network pharmacology analysis followed by experimental validation was applied to explore the potential mechanisms of ZGW in promoting the osteogenesis of bone marrow mesenchymal stem cells(BMSCs).Results In total,487 no-repeat targets corresponding to the bioactive components of ZGW were screened,and 175 target genes in the intersection of ZGW and osteogenesis were obtained.And 28 core target genes were then obtained from a PPI network analysis.A GO functional enrichment analysis showed that the relevant biological processes mainly involve the cellular response to chemical stress,metal ions,and lipopolysaccharide.Additionally,KEGG pathway enrichment analysis revealed that multiple signaling pathways,including the phosphatidylinositol-3-kinase/protein kinase B(PI3K/AKT)signaling pathway,were associated with ZGW-promoted osteogensis.Further experimental validation showed that ZGW could increase alkaline phosphatase(ALP)activity as well as the mRNA and protein levels of ALP,osteocalcin(OCN),and runt related transcription factor 2(Runx 2).What’s more,Western blot analysis results showed that ZGW significantly increased the protein levels of p-PI3K and p-AKT,and the increases of these protein levels significantly receded after the addition of the PI3K inhibitor LY294002.Finally,the upregulated osteogenic-related indicators were also suppressed by the addition of LY294002.Conclusion ZGW promotes the osteogenesis of BMSCs via PI3K/AKT signaling pathway.展开更多
Being such a rare condition in paediatrics, osteogenesis imperfecta (OI) is not a diagnosis which is made often. It is however, a diagnosis necessitating early diagnosis and timeous and effective management to improve...Being such a rare condition in paediatrics, osteogenesis imperfecta (OI) is not a diagnosis which is made often. It is however, a diagnosis necessitating early diagnosis and timeous and effective management to improve morbidity and increase the quality of life for our patients. We report two cases of osteogenesis imperfecta in this case report to highlight the different phenotypic presentations. Both of these patients are unique in their presentations and each case highlights the importance of a high clinical index of suspicion by the practitioner in making the diagnosis of osteogenesis imperfecta. The first case is a patient who was diagnosed with osteogenesis imperfecta on day one of life. She had disproportionate short stature, blue sclera, a small chest and bowing of her lower limbs with swellings and tenderness over both of her femurs. A babygram radiograph revealed multiple fractures, with the presence of callus formation at some fracture sites suggesting intrauterine fractures. The second case is a patient who had normal anthropometry and was well at birth. She was subsequently diagnosed at two weeks of age when she presented to the Chris Hani Baragwanath Academic Hospital with an E. coli meningitis and she was suspected to have a right clavicular fracture and possibly rib fractures as she had pain on palpation over these areas. She was noted to have no blue sclera. Subsequent X-rays confirmed a right clavicular fracture as well as left and right rib fractures at different stages of healing. A lateral skull radiograph revealed Wormian bones. With no available genetic testing in South Africa, both diagnoses were made clinically. Both of our patients were started on zoledronic acid at three months of age and were followed up by the Metabolic Unit at the Chis Hani Baragwanath Academic Hospital. This case report of two patients highlights the characteristics important in diagnosing and treating this uncommon condition with varying phenotypical presentations, thus ensuring that the diagnosis is not missed or misdiagnosed: one disorder, two different faces.展开更多
Ginsenoside Rb1, the effective constituent of ginseng, has been demonstrated to play favorable roles in improving the immunity system. However, there is little study on the osteogenesis and angiogenesis effect of Gins...Ginsenoside Rb1, the effective constituent of ginseng, has been demonstrated to play favorable roles in improving the immunity system. However, there is little study on the osteogenesis and angiogenesis effect of Ginsenoside Rb1. Moreover, how to establish a delivery system of Ginsenoside Rb1 and its repairment ability in bone defect remains elusive. In this study, the role of Ginsenoside Rb1 in cell viability, proliferation, apoptosis, osteogenic genes expression, ALP activity of rat BMSCs were evaluated firstly. Then,micro-nano HAp granules combined with silk were prepared to establish a delivery system of Ginsenoside Rb1, and the osteogenic and angiogenic effect of Ginsenoside Rb1 loaded on micro-nano HAp/silk in rat calvarial defect models were assessed by sequential fluorescence labeling, and histology analysis, respectively. It revealed that Ginsenoside Rb1 could maintain cell viability, significantly increased ALP activity, osteogenic and angiogenic genes expression. Meanwhile, micro-nano HAp granules combined with silk were fabricated smoothly and were a delivery carrier for Ginsenoside Rb1. Significantly, Ginsenoside Rb1 loaded on micro-nano HAp/silk could facilitate osteogenesis and angiogenesis. All the outcomes hint that Ginsenoside Rb1 could reinforce the osteogenesis differentiation and angiogenesis factor’s expression of BMSCs. Moreover, micro-nano HAp combined with silk could act as a carrier for Ginsenoside Rb1 to repair bone defect.展开更多
Objective:To explore the effect of sustained-release recombinant human bone morphogenetic protein-2(rhBMP-2) on ectopic osteogenesis in the muscle pouches of rats through preparing rhBMP-2 sustained-release capsules b...Objective:To explore the effect of sustained-release recombinant human bone morphogenetic protein-2(rhBMP-2) on ectopic osteogenesis in the muscle pouches of rats through preparing rhBMP-2 sustained-release capsules by wrapping morphogenesis protein bones-2(BMP-2)using chitosan nanoparticles,and compositing collagen materials.Methods:Twenty four SpragueDawley rats were randomly divided into four groups with six rats in each group,that is Group A(control group),Group B(only treated with collagen),Group C(rhBMP-2+collagen treated group) and Group D(rhBMP-2/cs+collagen treated group).The composite materials for each group were implanted in the bilateral peroneal muscle pouches in rats.The peroneal muscles were only separated without implanting any materials in control group.Rats were sacrificed 2 weeks and 4 weeks post treatment and samples were cut off for general observation,Micro CT scans and histological observation.Results:General observation showed no new bone formation in Groups A and B mice,while new bones were formed in Groups C and D mice.Two weeks after treatment Micro CT scans showed that The bone volume fraction(BVF),trabecular thickness(Tb. Th),bone mineral density(BMD) in Group C mice were all higher than that in Group D(P<0.05). At the fourth week,the BVK,Tb.Th and BMD were significantly higher than that at the second week(P<0.01).Conclusions:The slow-release effect of rhBMP-2/cs sustained-release capsules can significantly promote ectopic osteogenesis.Its bone formation effect is better than that of rhBMP-2 burst-release group.展开更多
BACKGROUND A major problem in the healing of bone defects is insufficient or absent blood supply within the defect.To overcome this challenging problem,a plethora of approaches within bone tissue engineering have been...BACKGROUND A major problem in the healing of bone defects is insufficient or absent blood supply within the defect.To overcome this challenging problem,a plethora of approaches within bone tissue engineering have been developed recently.Bearing in mind that the interplay of various diffusible factors released by endothelial cells(ECs)and osteoblasts(OBs)have a pivotal role in bone growth and regeneration and that adjacent ECs and OBs also communicate directly through gap junctions,we set the focus on the simultaneous application of these cell types together with platelet-rich plasma(PRP)as a growth factor reservoir within ectopic bone tissue engineering constructs.AIM To vascularize and examine osteogenesis in bone tissue engineering constructs enriched with PRP and adipose-derived stem cells(ASCs)induced into ECs and OBs.METHODS ASCs isolated from adipose tissue,induced in vitro into ECs,OBs or just expanded were used for implant construction as followed:BPEO,endothelial and osteogenic differentiated ASCs with PRP and bone mineral matrix;BPUI,uninduced ASCs with PRP and bone mineral matrix;BC(control),only bone mineral matrix.At 1,2,4 and 8 wk after subcutaneous implantation in mice,implants were extracted and endothelial-related and bone-related gene expression were analyzed,while histological analyses were performed after 2 and 8 wk.RESULTS The percentage of vascularization was significantly higher in BC compared to BPUI and BPEO constructs 2 and 8 wk after implantation.BC had the lowest endothelial-related gene expression,weaker osteocalcin immunoexpression and Spp1 expression compared to BPUI and BPEO.Endothelial-related gene expression and osteocalcin immunoexpression were higher in BPUI compared to BC and BPEO.BPEO had a higher percentage of vascularization compared to BPUI and the highest CD31 immunoexpression among examined constructs.Except Vwf,endothelial-related gene expression in BPEO had a later onset and was upregulated and well-balanced during in vivo incubation that induced late onset of Spp1 expression and pronounced osteocalcin immunoexpression at 2 and 8 wk.Tissue regression was noticed in BPEO constructs after 8 wk.CONCLUSION Ectopically implanted BPEO constructs had a favorable impact on vascularization and osteogenesis,but tissue regression imposed the need for discovering a more optimal EC/OB ratio prior to considerations for clinical applications.展开更多
Poly methyl methacrylate(PMMA)bone cement is used in augmenting and stabilizing fractured vertebral bodies through percutaneous vertebroplasty(PVP)and percutaneous kyphoplasty(PKP).However,applications of PMMA bone ce...Poly methyl methacrylate(PMMA)bone cement is used in augmenting and stabilizing fractured vertebral bodies through percutaneous vertebroplasty(PVP)and percutaneous kyphoplasty(PKP).However,applications of PMMA bone cement are limited by the high elasticity modulus of PMMA,its low biodegradability,and its limited ability to regenerate bone.To improve PMMA bio activity and biodegradability and to modify its elasticity modulus,we mixed PMMA bone cement with oxidized hyaluronic acid and carboxymethyl chitosan in situ cross-linking hydrogel loaded with bone morphogenetic protein-2(BMP-2)to achieve novel hybrid cement.These fabric ated PMMA-hydrogel hybrid cements exhibited lower setting temperatures,a lower elasticity modulus,and better biodegradability and biocompatibility than that of pure PMMA cement,while retaining acceptable setting times,mechanical strength,and inj ectability.In addition,we detected release of BMP-2 from the PMMA-hydrogel hybrid cements,significantly enhancing in vitro osteogenesis of bone marrow mesenchymal stem cells by up-regulating the gene expression of Runx2,Coll,and OPN.Use of PMMA-hydrogel hybrid cements loaded with BMP-2 on rabbit femoral condyle bone-defect models revealed their biodegradability and enhanced bone formation.Our study demonstrated the favorable mechanical properties,biocompatibility,and biodegradability of fabricated PMMA-hydrogel hybrid cements loaded with BMP-2,as well as their ability to improve osteogenesis,making them a promising material for use in PKP and PVP.展开更多
Repair and regeneration of bone requires mesenchymal stem cells that by self-renewal,are able to generate a critical mass of cells with the ability to differentiate into osteoblasts that can produce bone protein matri...Repair and regeneration of bone requires mesenchymal stem cells that by self-renewal,are able to generate a critical mass of cells with the ability to differentiate into osteoblasts that can produce bone protein matrix(osteoid)and enable its mineralization.The number of human mesenchymal stem cells(hMSCs)diminishes with age and ex vivo replication of hMSCs has limited potential.While propagating hMSCs under hypoxic conditions may maintain their ability to self-renew,the strategy of using human telomerase reverse transcriptase(hTERT)to allow for hMSCs to prolong their replicative lifespan is an attractive means of ensuring a critical mass of cells with the potential to differentiate into various mesodermal structural tissues including bone.However,this strategy must be tempered by the oncogenic potential of TERT-transformed cells,or their ability to enhance already established cancers,the unknown differentiating potential of high population doubling hMSCs and the source of hMSCs(e.g.,bone marrow,adipose-derived,muscle-derived,umbilical cord blood,etc.)that may provide peculiarities to self-renewal,differentiation,and physiologic function that may differ from non-transformed native cells.Tissue engineering approaches to use hMSCs to repair bone defects utilize the growth of hMSCs on three-dimensional scaffolds that can either be a base on which hMSCs can attach and grow or as a means of sequestering growth factors to assist in the chemoattraction and differentiation of native hMSCs.The use of whole native extracellular matrix(ECM)produced by hMSCs,rather than individual ECM components,appear to be advantageous in not only being utilized as a three-dimensional attachment base but also in appropriate orientation of cells and their differentiation through the growth factors that native ECM harbor or in simulating growth factor motifs.The origin of native ECM,whether from hMSCs from young or old individuals is a critical factor in"rejuvenating"hMSCs from older individuals grown on ECM from younger individuals.展开更多
Osteogenesis imperfecta(OI) is a rare inherited connective tissue disorder caused by mutation of collagen which results in a wide spectrum of clinical manifestations including long bone fragility fractures and deformi...Osteogenesis imperfecta(OI) is a rare inherited connective tissue disorder caused by mutation of collagen which results in a wide spectrum of clinical manifestations including long bone fragility fractures and deformities. While the treatment for these fractures was recommended as using intramedullary fixation for minimizing stress concentration, the selection of the best implant in the adolescent OI patients for the surgical reconstruction of femur was still problematic, due to anatomy distortion and implant availability. We are reporting the surgical modification by using a humeral nail for femoral fixation in three adolescent OI patients with favorable outcomes.展开更多
Objective: To apply trifocal distraction osteogenesis in canine model of skull segmental defects and to provide reference for clinical treatment. Methods: Six labrador dogs were selected in this study and divided into...Objective: To apply trifocal distraction osteogenesis in canine model of skull segmental defects and to provide reference for clinical treatment. Methods: Six labrador dogs were selected in this study and divided into observation group and control group randomly. Each group contained 3 dogs. Skull segmental defects models were established by surgery, and dogs in bservation group received trifocal distraction osteogenesis treatment. Bone density was observed and compared between two groups during treatment. Results: There were no significant difference in bone density between two groups on th 1st day ( P>0.05). The bone density of observation group on the 30th day, and 60th day were higher than that of control group ( P<0.01). Conclusions: Trifocal distraction osteogenesis has significant clinical effect, and it would be widely used in clinical treatment.展开更多
Objective:To investigate the synergistic effect and mechanism of the combined application of recombinant human bone morphogenetic protein-2(rhBMP-2) and basic fibroblast growth factor(bFGF).Methods:24 KM male mice wer...Objective:To investigate the synergistic effect and mechanism of the combined application of recombinant human bone morphogenetic protein-2(rhBMP-2) and basic fibroblast growth factor(bFGF).Methods:24 KM male mice were randomly divided into 6 groups with 4 mice in each group,namely,Group A(control group),Group B(only treated with collagen),Group C(treated with2 ng bFGF+collagen).Group D(treated with 4μg rhBMP-2+collagen),Group E(treated with 4 μg rhBMP-2+2 ng bFGF+collagen) and Group F(treated with 4 μg rhBMP-2+4 ng bFGF+collagem.The composites were implanted into the intermuscular septum of hind legs mice:whereas in control group,intermuscular septum of mice was separated and no implantation was performed.General observation,detection of concentration of calcium content,micro computed tomography(Micro-CT).three-dimensional reconstruction scan.measurement of bone mineral density(BMD).bone volume fraction(BVF) and trabecular thickness(Tb.Th).as well as histological observation with HE staining and ALP and CD34 immumohistochemical staining were performed.Results:Ectopic osteogenesis was found in Groups D.F and F mice.The difference in concentration of calcium contents was statistically significant between Groups D and E(P<0.05),but insignificant between Groups E and F(P>0.05).Micro-CT and three-dimensional reconstruction revealed continuous newborn bone substance in external surface of ectopic bone formation,and the center of bone formation did not show obvious substantial filling by bone substance.The differences in BMD,BVF and Tb.Th were statistically significant between Groups D and E or F(P<0.01 or <0.05).HE staining showed that in Groups D.E and F.newborn bone substance was mainly located at the edge of ectopic bone formation,and the bone formation in Groups E and F was better than that in Group D.ALP and CD34 immumohistochemical staining revealed the positive expression mainly at the edge of ectopic bone formation,and area of positive expression in Groups E and F was larger than that in Groups D.Conclusions:rhBMP-2 possesses the capacity to induce ectopic osteogenesis independently,but bFGF does not have this ability;the combined application of rhBMP-2 and bFGF can enhance the synergetic effect on inducing ectopic osteogenesis.展开更多
Distraction osteogenesis(DO) is widely used for bone tissue engineering technology. Immune regulations play important roles in the process of DO like other bone regeneration mechanisms. Compared with others, the immun...Distraction osteogenesis(DO) is widely used for bone tissue engineering technology. Immune regulations play important roles in the process of DO like other bone regeneration mechanisms. Compared with others, the immune regulation processes of DO have their distinct features. In this review, we summarized the immune-related events including changes in and effects of immune cells, immune-related cytokines, and signaling pathways at different periods in the process of DO. We aim to elucidated our understanding and unknowns about the immunomodulatory role of DO. The goal of this is to use the known knowledge to further modify existing methods of DO, and to develop novel DO strategies in our unknown areas through more detailed studies of the work we have done.展开更多
We have previously reported on both the osteogenic potential of hydroxyapatite (HA) combined with bone marrow-derived mesenchymal stem cells (BMSCs) and a method involving osteogenic matrix cell sheet transplantation ...We have previously reported on both the osteogenic potential of hydroxyapatite (HA) combined with bone marrow-derived mesenchymal stem cells (BMSCs) and a method involving osteogenic matrix cell sheet transplantation of BMSCs. In the present study, we assessed the osteogenic potential of serially-passaged BMSCs, both in vitro and in vivo. We also assessed whether an additional cell-loading technique can regain the osteogenic potential of the constructs combined with serially-passaged BMSCs. The present study revealed that passage (P) 1 cells cultured in osteogenic-induced medium showed strong positive staining for alkaline phosphatase (ALP) and Alizarin Red S, whereas P3 cells showed faint staining for ALP, with no Alizarin Red S staining. Staining of P1, P2 and P3 cells were progressively weaker, indicating that the osteogenic potential of the serially-passaged rat BMSCs is lost after P3 in vitro. The in vivo study showed that little bone formation was observed in the HA constructs seeded with P3 cells, 4 weeks after subcutaneous implantation. However, P3 cell/HA constructs which had increased cell-loading showed abundant bone formation within the pores of the HA construct. ALP and osteocalcin mRNA expression in these constructs was significantly higher than that of constructs with regular cell-seeding. The present study indicates that the osteogenic potential of the constructs with serially-passaged BMSCs is increased by additional cell-loading. This method can be applied to cases requiring hard tissue reconstruction, where BMSCs require serial expansion of cells.展开更多
The allogenic bone marrow derived mesenchymal stem cells transplantation was given to the newborn girl diagnosed with osteogenesis imperfecta type III, with multiple bone fractures, extreme shortness and limbs deformi...The allogenic bone marrow derived mesenchymal stem cells transplantation was given to the newborn girl diagnosed with osteogenesis imperfecta type III, with multiple bone fractures, extreme shortness and limbs deformities. The treatment was performed at the age of 4 and 6 weeks. The clinical diagnosis was supported by biochemical analysis of collagen type I recovered from culture medium of cultivated patient’s skin fibroblast, which revealed its triple helix instability at temperature about 2?C lower than normal. Sequencing of both genes encoding procollagen type I revealed heterozygous substitution G23569Ain COL1A2 gene causing change of glycine at position 517 to aspartate. The donor of mesenchymal stem cells was the girl’s father. She received two intravenous infusions of suspended cultured mesenchymal cells in 16 days apart without any side effects. An analysis of procollagen type I secreted to the culture medium by bone marrow-derived mesenchymal stem cells obtained from the patient, 3 months following transplantation revealed its normal triple helix stability. During the subsequent two years of follow up two new bone fractures were noted. Currently a two-year-old girl’s presents extreme growth and weight deficiency. The motoric development is also retarded, but the patient constantly improves and makes progresses.展开更多
Objective: skeletal advancement in order to improve the airway dimensions is known as one of the most effective surgical theraphy for treating obstructive sleep apnea (OSA). Distraction osteogenesis (DO) can be a bett...Objective: skeletal advancement in order to improve the airway dimensions is known as one of the most effective surgical theraphy for treating obstructive sleep apnea (OSA). Distraction osteogenesis (DO) can be a better treatment alternative in some selected cases similar to our patient. Using custom made distractors can make this technique more safe and successful. Study Design: Surgically assisted rapid palatal expansion (SARPE), bilateral intraoral mandibular distraction osteogenesis (MDO) and orthodontic treatment were tried to a 20-year-old OSA patient with orthognathic anomaly. For mandibular distraction, custom made distractors were used. Results: The initial AHI of the patient was 23.3. At the end of the treatment it decreased to 8.7. Conclusions: Distraction osteogenesis could be a better alternative than the conventional orthognathic surgery in this kind of selected patients. Customization of the distraction devices can contribute to making this procedure safer and more successful.展开更多
AIM To establish a hypoxic environment for promoting osteogenesis in rat marrow stromal cells(MSCs) using osteogenic matrix cell sheets(OMCSs).METHODS Rat MSCs were cultured in osteogenic media under one of four varyi...AIM To establish a hypoxic environment for promoting osteogenesis in rat marrow stromal cells(MSCs) using osteogenic matrix cell sheets(OMCSs).METHODS Rat MSCs were cultured in osteogenic media under one of four varying oxygen conditions: Normoxia(21% O_2) for 14 d(NN), normoxia for 7 d followed by hypoxia(5% O_2) for 7 d(NH), hypoxia for 7 d followed by normoxia for 7 d(HN), or hypoxia for 14 d(HH). Osteogenesis was evaluated by observing changes in cell morphology and calcium deposition, and by measuring osteocalcin secretion(ELISA) and calcium content. In vivo syngeneic transplantation using OMCSs and β-tricalcium phosphate discs, preconditioned under NN or HN conditions, was also evaluated by histology, calcium content measurements,and real-time quantitative PCR.RESULTS In the NN and HN groups, differentiated, cuboidal-shaped cells were readily observed, along with calcium deposits. In the HN group, the levels of secreted osteocalcin increased rapidly from day 10 as compared with the other groups, and plateaued at day 12(P < 0.05). At day 14, the HN group showed the highest amount of calcium deposition. In vivo, the HN group showed histologically prominent new bone formation, increased calcium deposition, and higher collagen type Ⅰ?messenger RNA expression as compared with the NN group.CONCLUSION The results of this study indicate that modifying oxygen tension is an effective method to enhance the osteogenic ability of MSCs used for OMCSs.展开更多
Objective To investigate the histological changes of rapid tooth movement in dogs treated by resistance reduction and distraction osteogenesis,aiming to establish an animal model and further to reveal the remodeling m...Objective To investigate the histological changes of rapid tooth movement in dogs treated by resistance reduction and distraction osteogenesis,aiming to establish an animal model and further to reveal the remodeling mechanism of rapid tooth movement. Methods A total of 8 local hybrid dogs were selected as subjects for this study. The second pre-molar was extracted on both sides. The experimental side underwent alvelor surgery for resistance reduction and a home-made tooth-borne intraoral distraction device was installed for rapid tooth movement,while for the other side (control side) only tooth-borne intraoral distraction device was used for rapid tooth movement. The longest active force-delivery span was 2 weeks,followed by 6-week retention. The distance between the moved tooth and anchor unit was recorded weekly,and radiography was performed for each side before and after distraction. The surrounding tissues including periodontal ligament and alveolar bone were sectioned for histological analysis. Results The average distance of tooth movement was 3.55mm on the experimental side and 1.11mm on the control side. The rate of tooth movement was notably higher (P<0.01) and no significant apical root resorption was detected by X-ray on the experimental side. The active alvelor bone remodeling was found on the tension and pressure sides. However,there was no significant difference between the experimental side and the control side after the retention period. Conclusion The rate of orthodontic tooth movement can be accelerated through resistance reduction and periodontal distraction without any unfavorable effects but at minimal anchorage loss.展开更多
Periodontitis,as a chronic inflammatory disease,remains unsolved,and the pathogenesis of this disease has not been fully elucidated.In this study,the effect of miR-4262 was investigated in tumor necrosis factor-α(TNF...Periodontitis,as a chronic inflammatory disease,remains unsolved,and the pathogenesis of this disease has not been fully elucidated.In this study,the effect of miR-4262 was investigated in tumor necrosis factor-α(TNF-α)induced human periodontal stem cells(hPDLSCs)for the first time.The gene expression involved in this study was determined using polymerase chain reaction(PCR),the expressions of relevant proteins were determined by western blot analysis,and the levels of IL-1β,IL-6,and MCP-1 were estimated by enzyme-linked immunosorbent assay(ELISA)assay.The luciferase reporter assay was performed for verification of the target gene,alkaline phosphatase(ALP)activity detection was used for differentiation capacity,and alizarin red staining assay was used for mineralization capacity.The inhibition of miRNA-4262,which resulted in the upregulation of suppressor of cytokine signaling 4(SOCS4),showed protective effects,including anti-inflammation and promotional effects on osteogenesis as well as differentiation in TNF-αinduced hPDLSCs.These results provided insights into the roles of miRNAs in regulating the inflammatory response,differentiation,and osteogenesis in hPDLSCs,which may promote the understanding of the mechanisms of periodontitis and find out a better therapeutic application.展开更多
基金supported by the National Natural Science Foundation of China [82172385 to H.S., 82172349 to Y.W.]the Key-Area Research and Development Program of Guangdong Province [2019B020236001 to H.S.]+3 种基金the Shenzhen Key Medical Discipline Construction Fund [ZDSYS20190902092851024 to H.S.]the Natural Science Foundation of Guangdong Province [2020A1515010097 to Z.X.]the Shenzhen Outstanding Science and Technology Innovation Talents-Outstanding Youth Fund project [RCYX20210706092106042 to Z.X.]Funding for open access charge:Shenzhen Key Medical Discipline Construction Fund。
文摘As the major cell precursors in osteogenesis, mesenchymal stem cells(MSCs) are indispensable for bone homeostasis and development. However, the primary mechanisms regulating osteogenic differentiation are controversial. Composed of multiple constituent enhancers, super enhancers(SEs) are powerful cis-regulatory elements that identify genes that ensure sequential differentiation. The present study demonstrated that SEs were indispensable for MSC osteogenesis and involved in osteoporosis development. Through integrated analysis, we identified the most common SE-targeted and osteoporosis-related osteogenic gene,ZBTB16. ZBTB16, positively regulated by SEs, promoted MSC osteogenesis but was expressed at lower levels in osteoporosis.Mechanistically, SEs recruited bromodomain containing 4(BRD4) at the site of ZBTB16, which then bound to RNA polymerase IIassociated protein 2(RPAP2) that transported RNA polymerase Ⅱ(POL Ⅱ) into the nucleus. The subsequent synergistic regulation of POL Ⅱ carboxyterminal domain(CTD) phosphorylation by BRD4 and RPAP2 initiated ZBTB16 transcriptional elongation, which facilitated MSC osteogenesis via the key osteogenic transcription factor SP7. Bone-targeting ZBTB16 overexpression had a therapeutic effect on the decreased bone density and remodeling capacity of Brd4^(fl/fl)Prx1-cre mice and osteoporosis(OP) models.Therefore, our study shows that SEs orchestrate the osteogenesis of MSCs by targeting ZBTB16 expression, which provides an attractive focus and therapeutic target for osteoporosis.
基金supported by the Key Research and Development Program of Shaanxi Province (2019ZDLSF03-06) and (2020ZDLGY13-05)the National Key Research and Development Program of China (2020YFC1107202)。
文摘Magnesium(Mg) and its alloys have been intensively studied to develop the next generation of bone implants recently, but their clinical application is restricted by rapid degradation and unsatisfied osteogenic effect in vivo. A bioactive chemical conversion Mg-phenolic networks complex coating(e EGCG) was stepwise incorporated by epigallocatechin-3-gallate(EGCG) and exogenous Mg^(2+)on Mg-2Zn magnesium alloy. Simplex EGCG induced chemical conversion coating(c EGCG) was set as compare group. The in vitro corrosion behavior of Mg-2Zn alloy, c EGCG and e EGCG was evaluated in SBF using electrochemical(PDP, EIS) and immersion test. The cytocompatibility was investigated with rat bone marrow mesenchymal stem cells(r BMSCs). Furthermore, the in vivo tests using a rabbit model involved micro computed tomography(Micro-CT) analysis, histological observation, and interface analysis. The results showed that the e EGCG is Mgphenolic multilayer coating incorporated Mg-phenolic networks, which is rougher, more compact and much thicker than c EGCG. The e EGCG highly improved the corrosion resistance of Mg-2Zn alloy, combined with its lower average hemolytic ratios, continuous high scavenging effect ability and relatively moderate contact angle features, resulting in a stable and suitable biological environment, obviously promoted r BMSCs adhesion and proliferation. More importantly, Micro-CT, histological and interface elements distribution evaluations all revealed that the e EGCG effectively inhibited degradation and enhanced bone tissue formation of Mg alloy implants. This study puts forward a promising bioactive chemical conversion coating with Mg-phenolic networks for the application of biodegradable orthopedic implants.
文摘Osteogenesis imperfecta(OI)is a genetically heterogeneous monogenic disease characterized by decreased bone mass,bone fragility,and recurrent fractures.The phenotypic spectrum varies considerably ranging from prenatal fractures with lethal outcomes to mild forms with few fractures and normal stature.The basic mechanism is a collagen-related defect,not only in synthesis but also in folding,processing,bone mineralization,or osteoblast function.In recent years,great progress has been made in identifying new genes and molecular mechanisms underlying OI.In this context,the classification of OI has been revised several times and different types are used.The Sillence classification,based on clinical and radiological characteristics,is currently used as a grading of clinical severity.Based on the metabolic pathway,the functional classification allows identifying regulatory elements and targeting specific therapeutic approaches.Genetic classification has the advantage of identifying the inheritance pattern,an essential element for genetic counseling and prophylaxis.Although genotype-phenotype correlations may sometimes be challenging,genetic diagnosis allows a personalized management strategy,accurate family planning,and pregnancy management decisions including options for mode of delivery,or early antenatal OI treatment.Future research on molecular pathways and pathogenic variants involved could lead to the development of genotype-based therapeutic approaches.This narrative review summarizes our current understanding of genes,molecular mechanisms involved in OI,classifications,and their utility in prophylaxis.
文摘Objective Osteogenesis is vitally important for bone defect repair,and Zuo Gui Wan(ZGW)is a classic prescription in traditional Chinese medicine(TCM)for strengthening bones.However,the specific mechanism by which ZGW regulates osteogenesis is still unclear.The current study is based on a network pharmacology analysis to explore the potential mechanism of ZGW in promoting osteogenesis.Methods A network pharmacology analysis followed by experimental validation was applied to explore the potential mechanisms of ZGW in promoting the osteogenesis of bone marrow mesenchymal stem cells(BMSCs).Results In total,487 no-repeat targets corresponding to the bioactive components of ZGW were screened,and 175 target genes in the intersection of ZGW and osteogenesis were obtained.And 28 core target genes were then obtained from a PPI network analysis.A GO functional enrichment analysis showed that the relevant biological processes mainly involve the cellular response to chemical stress,metal ions,and lipopolysaccharide.Additionally,KEGG pathway enrichment analysis revealed that multiple signaling pathways,including the phosphatidylinositol-3-kinase/protein kinase B(PI3K/AKT)signaling pathway,were associated with ZGW-promoted osteogensis.Further experimental validation showed that ZGW could increase alkaline phosphatase(ALP)activity as well as the mRNA and protein levels of ALP,osteocalcin(OCN),and runt related transcription factor 2(Runx 2).What’s more,Western blot analysis results showed that ZGW significantly increased the protein levels of p-PI3K and p-AKT,and the increases of these protein levels significantly receded after the addition of the PI3K inhibitor LY294002.Finally,the upregulated osteogenic-related indicators were also suppressed by the addition of LY294002.Conclusion ZGW promotes the osteogenesis of BMSCs via PI3K/AKT signaling pathway.
文摘Being such a rare condition in paediatrics, osteogenesis imperfecta (OI) is not a diagnosis which is made often. It is however, a diagnosis necessitating early diagnosis and timeous and effective management to improve morbidity and increase the quality of life for our patients. We report two cases of osteogenesis imperfecta in this case report to highlight the different phenotypic presentations. Both of these patients are unique in their presentations and each case highlights the importance of a high clinical index of suspicion by the practitioner in making the diagnosis of osteogenesis imperfecta. The first case is a patient who was diagnosed with osteogenesis imperfecta on day one of life. She had disproportionate short stature, blue sclera, a small chest and bowing of her lower limbs with swellings and tenderness over both of her femurs. A babygram radiograph revealed multiple fractures, with the presence of callus formation at some fracture sites suggesting intrauterine fractures. The second case is a patient who had normal anthropometry and was well at birth. She was subsequently diagnosed at two weeks of age when she presented to the Chris Hani Baragwanath Academic Hospital with an E. coli meningitis and she was suspected to have a right clavicular fracture and possibly rib fractures as she had pain on palpation over these areas. She was noted to have no blue sclera. Subsequent X-rays confirmed a right clavicular fracture as well as left and right rib fractures at different stages of healing. A lateral skull radiograph revealed Wormian bones. With no available genetic testing in South Africa, both diagnoses were made clinically. Both of our patients were started on zoledronic acid at three months of age and were followed up by the Metabolic Unit at the Chis Hani Baragwanath Academic Hospital. This case report of two patients highlights the characteristics important in diagnosing and treating this uncommon condition with varying phenotypical presentations, thus ensuring that the diagnosis is not missed or misdiagnosed: one disorder, two different faces.
基金supported by National Natural Science Foundation of China (81600828)Shanghai Sailing Program (16YF1406600)
文摘Ginsenoside Rb1, the effective constituent of ginseng, has been demonstrated to play favorable roles in improving the immunity system. However, there is little study on the osteogenesis and angiogenesis effect of Ginsenoside Rb1. Moreover, how to establish a delivery system of Ginsenoside Rb1 and its repairment ability in bone defect remains elusive. In this study, the role of Ginsenoside Rb1 in cell viability, proliferation, apoptosis, osteogenic genes expression, ALP activity of rat BMSCs were evaluated firstly. Then,micro-nano HAp granules combined with silk were prepared to establish a delivery system of Ginsenoside Rb1, and the osteogenic and angiogenic effect of Ginsenoside Rb1 loaded on micro-nano HAp/silk in rat calvarial defect models were assessed by sequential fluorescence labeling, and histology analysis, respectively. It revealed that Ginsenoside Rb1 could maintain cell viability, significantly increased ALP activity, osteogenic and angiogenic genes expression. Meanwhile, micro-nano HAp granules combined with silk were fabricated smoothly and were a delivery carrier for Ginsenoside Rb1. Significantly, Ginsenoside Rb1 loaded on micro-nano HAp/silk could facilitate osteogenesis and angiogenesis. All the outcomes hint that Ginsenoside Rb1 could reinforce the osteogenesis differentiation and angiogenesis factor’s expression of BMSCs. Moreover, micro-nano HAp combined with silk could act as a carrier for Ginsenoside Rb1 to repair bone defect.
基金supported by Guangdong Province Science and Technology Foundation,Guangdong,China(No:2011B080701053)
文摘Objective:To explore the effect of sustained-release recombinant human bone morphogenetic protein-2(rhBMP-2) on ectopic osteogenesis in the muscle pouches of rats through preparing rhBMP-2 sustained-release capsules by wrapping morphogenesis protein bones-2(BMP-2)using chitosan nanoparticles,and compositing collagen materials.Methods:Twenty four SpragueDawley rats were randomly divided into four groups with six rats in each group,that is Group A(control group),Group B(only treated with collagen),Group C(rhBMP-2+collagen treated group) and Group D(rhBMP-2/cs+collagen treated group).The composite materials for each group were implanted in the bilateral peroneal muscle pouches in rats.The peroneal muscles were only separated without implanting any materials in control group.Rats were sacrificed 2 weeks and 4 weeks post treatment and samples were cut off for general observation,Micro CT scans and histological observation.Results:General observation showed no new bone formation in Groups A and B mice,while new bones were formed in Groups C and D mice.Two weeks after treatment Micro CT scans showed that The bone volume fraction(BVF),trabecular thickness(Tb. Th),bone mineral density(BMD) in Group C mice were all higher than that in Group D(P<0.05). At the fourth week,the BVK,Tb.Th and BMD were significantly higher than that at the second week(P<0.01).Conclusions:The slow-release effect of rhBMP-2/cs sustained-release capsules can significantly promote ectopic osteogenesis.Its bone formation effect is better than that of rhBMP-2 burst-release group.
基金Supported by Ministry of Education,Science and Technological Development of the Republic of Serbia,No.III 41017.
文摘BACKGROUND A major problem in the healing of bone defects is insufficient or absent blood supply within the defect.To overcome this challenging problem,a plethora of approaches within bone tissue engineering have been developed recently.Bearing in mind that the interplay of various diffusible factors released by endothelial cells(ECs)and osteoblasts(OBs)have a pivotal role in bone growth and regeneration and that adjacent ECs and OBs also communicate directly through gap junctions,we set the focus on the simultaneous application of these cell types together with platelet-rich plasma(PRP)as a growth factor reservoir within ectopic bone tissue engineering constructs.AIM To vascularize and examine osteogenesis in bone tissue engineering constructs enriched with PRP and adipose-derived stem cells(ASCs)induced into ECs and OBs.METHODS ASCs isolated from adipose tissue,induced in vitro into ECs,OBs or just expanded were used for implant construction as followed:BPEO,endothelial and osteogenic differentiated ASCs with PRP and bone mineral matrix;BPUI,uninduced ASCs with PRP and bone mineral matrix;BC(control),only bone mineral matrix.At 1,2,4 and 8 wk after subcutaneous implantation in mice,implants were extracted and endothelial-related and bone-related gene expression were analyzed,while histological analyses were performed after 2 and 8 wk.RESULTS The percentage of vascularization was significantly higher in BC compared to BPUI and BPEO constructs 2 and 8 wk after implantation.BC had the lowest endothelial-related gene expression,weaker osteocalcin immunoexpression and Spp1 expression compared to BPUI and BPEO.Endothelial-related gene expression and osteocalcin immunoexpression were higher in BPUI compared to BC and BPEO.BPEO had a higher percentage of vascularization compared to BPUI and the highest CD31 immunoexpression among examined constructs.Except Vwf,endothelial-related gene expression in BPEO had a later onset and was upregulated and well-balanced during in vivo incubation that induced late onset of Spp1 expression and pronounced osteocalcin immunoexpression at 2 and 8 wk.Tissue regression was noticed in BPEO constructs after 8 wk.CONCLUSION Ectopically implanted BPEO constructs had a favorable impact on vascularization and osteogenesis,but tissue regression imposed the need for discovering a more optimal EC/OB ratio prior to considerations for clinical applications.
基金supported by the National Key R&D Program of China(No.2018YFA0703000)the National Natural Science Foundation of China(Nos.82071564,82072412,and 81772326)+1 种基金the Fundamental Research Program Funding of Ninth People’s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine(No.JYZZ070)Project of Shanghai Science and Technology Commission(No.19XD1434200/18431903700)。
文摘Poly methyl methacrylate(PMMA)bone cement is used in augmenting and stabilizing fractured vertebral bodies through percutaneous vertebroplasty(PVP)and percutaneous kyphoplasty(PKP).However,applications of PMMA bone cement are limited by the high elasticity modulus of PMMA,its low biodegradability,and its limited ability to regenerate bone.To improve PMMA bio activity and biodegradability and to modify its elasticity modulus,we mixed PMMA bone cement with oxidized hyaluronic acid and carboxymethyl chitosan in situ cross-linking hydrogel loaded with bone morphogenetic protein-2(BMP-2)to achieve novel hybrid cement.These fabric ated PMMA-hydrogel hybrid cements exhibited lower setting temperatures,a lower elasticity modulus,and better biodegradability and biocompatibility than that of pure PMMA cement,while retaining acceptable setting times,mechanical strength,and inj ectability.In addition,we detected release of BMP-2 from the PMMA-hydrogel hybrid cements,significantly enhancing in vitro osteogenesis of bone marrow mesenchymal stem cells by up-regulating the gene expression of Runx2,Coll,and OPN.Use of PMMA-hydrogel hybrid cements loaded with BMP-2 on rabbit femoral condyle bone-defect models revealed their biodegradability and enhanced bone formation.Our study demonstrated the favorable mechanical properties,biocompatibility,and biodegradability of fabricated PMMA-hydrogel hybrid cements loaded with BMP-2,as well as their ability to improve osteogenesis,making them a promising material for use in PKP and PVP.
基金Supported by Veterans Administration Merit Review Award 2 I01 BX000170-05
文摘Repair and regeneration of bone requires mesenchymal stem cells that by self-renewal,are able to generate a critical mass of cells with the ability to differentiate into osteoblasts that can produce bone protein matrix(osteoid)and enable its mineralization.The number of human mesenchymal stem cells(hMSCs)diminishes with age and ex vivo replication of hMSCs has limited potential.While propagating hMSCs under hypoxic conditions may maintain their ability to self-renew,the strategy of using human telomerase reverse transcriptase(hTERT)to allow for hMSCs to prolong their replicative lifespan is an attractive means of ensuring a critical mass of cells with the potential to differentiate into various mesodermal structural tissues including bone.However,this strategy must be tempered by the oncogenic potential of TERT-transformed cells,or their ability to enhance already established cancers,the unknown differentiating potential of high population doubling hMSCs and the source of hMSCs(e.g.,bone marrow,adipose-derived,muscle-derived,umbilical cord blood,etc.)that may provide peculiarities to self-renewal,differentiation,and physiologic function that may differ from non-transformed native cells.Tissue engineering approaches to use hMSCs to repair bone defects utilize the growth of hMSCs on three-dimensional scaffolds that can either be a base on which hMSCs can attach and grow or as a means of sequestering growth factors to assist in the chemoattraction and differentiation of native hMSCs.The use of whole native extracellular matrix(ECM)produced by hMSCs,rather than individual ECM components,appear to be advantageous in not only being utilized as a three-dimensional attachment base but also in appropriate orientation of cells and their differentiation through the growth factors that native ECM harbor or in simulating growth factor motifs.The origin of native ECM,whether from hMSCs from young or old individuals is a critical factor in"rejuvenating"hMSCs from older individuals grown on ECM from younger individuals.
文摘Osteogenesis imperfecta(OI) is a rare inherited connective tissue disorder caused by mutation of collagen which results in a wide spectrum of clinical manifestations including long bone fragility fractures and deformities. While the treatment for these fractures was recommended as using intramedullary fixation for minimizing stress concentration, the selection of the best implant in the adolescent OI patients for the surgical reconstruction of femur was still problematic, due to anatomy distortion and implant availability. We are reporting the surgical modification by using a humeral nail for femoral fixation in three adolescent OI patients with favorable outcomes.
基金supported by Shanghai Municipal Science and Technology Commission, International Cooperation Projects (No. 10410702100)
文摘Objective: To apply trifocal distraction osteogenesis in canine model of skull segmental defects and to provide reference for clinical treatment. Methods: Six labrador dogs were selected in this study and divided into observation group and control group randomly. Each group contained 3 dogs. Skull segmental defects models were established by surgery, and dogs in bservation group received trifocal distraction osteogenesis treatment. Bone density was observed and compared between two groups during treatment. Results: There were no significant difference in bone density between two groups on th 1st day ( P>0.05). The bone density of observation group on the 30th day, and 60th day were higher than that of control group ( P<0.01). Conclusions: Trifocal distraction osteogenesis has significant clinical effect, and it would be widely used in clinical treatment.
基金supported by Guangdong Provincial Technology and Development Foundation:(No:2012B0617000911 & No:2011B080701053)
文摘Objective:To investigate the synergistic effect and mechanism of the combined application of recombinant human bone morphogenetic protein-2(rhBMP-2) and basic fibroblast growth factor(bFGF).Methods:24 KM male mice were randomly divided into 6 groups with 4 mice in each group,namely,Group A(control group),Group B(only treated with collagen),Group C(treated with2 ng bFGF+collagen).Group D(treated with 4μg rhBMP-2+collagen),Group E(treated with 4 μg rhBMP-2+2 ng bFGF+collagen) and Group F(treated with 4 μg rhBMP-2+4 ng bFGF+collagem.The composites were implanted into the intermuscular septum of hind legs mice:whereas in control group,intermuscular septum of mice was separated and no implantation was performed.General observation,detection of concentration of calcium content,micro computed tomography(Micro-CT).three-dimensional reconstruction scan.measurement of bone mineral density(BMD).bone volume fraction(BVF) and trabecular thickness(Tb.Th).as well as histological observation with HE staining and ALP and CD34 immumohistochemical staining were performed.Results:Ectopic osteogenesis was found in Groups D.F and F mice.The difference in concentration of calcium contents was statistically significant between Groups D and E(P<0.05),but insignificant between Groups E and F(P>0.05).Micro-CT and three-dimensional reconstruction revealed continuous newborn bone substance in external surface of ectopic bone formation,and the center of bone formation did not show obvious substantial filling by bone substance.The differences in BMD,BVF and Tb.Th were statistically significant between Groups D and E or F(P<0.01 or <0.05).HE staining showed that in Groups D.E and F.newborn bone substance was mainly located at the edge of ectopic bone formation,and the bone formation in Groups E and F was better than that in Group D.ALP and CD34 immumohistochemical staining revealed the positive expression mainly at the edge of ectopic bone formation,and area of positive expression in Groups E and F was larger than that in Groups D.Conclusions:rhBMP-2 possesses the capacity to induce ectopic osteogenesis independently,but bFGF does not have this ability;the combined application of rhBMP-2 and bFGF can enhance the synergetic effect on inducing ectopic osteogenesis.
基金supported by grants from the National Key R&D Program of China (2016YFC1102800)National Natural Science Foundation of China (81879741, 51872332)+1 种基金Natural Science Foundation of Liaoning Province (20170541040)China Postdoctoral Science Foundation Grant (2020M681020)
文摘Distraction osteogenesis(DO) is widely used for bone tissue engineering technology. Immune regulations play important roles in the process of DO like other bone regeneration mechanisms. Compared with others, the immune regulation processes of DO have their distinct features. In this review, we summarized the immune-related events including changes in and effects of immune cells, immune-related cytokines, and signaling pathways at different periods in the process of DO. We aim to elucidated our understanding and unknowns about the immunomodulatory role of DO. The goal of this is to use the known knowledge to further modify existing methods of DO, and to develop novel DO strategies in our unknown areas through more detailed studies of the work we have done.
文摘We have previously reported on both the osteogenic potential of hydroxyapatite (HA) combined with bone marrow-derived mesenchymal stem cells (BMSCs) and a method involving osteogenic matrix cell sheet transplantation of BMSCs. In the present study, we assessed the osteogenic potential of serially-passaged BMSCs, both in vitro and in vivo. We also assessed whether an additional cell-loading technique can regain the osteogenic potential of the constructs combined with serially-passaged BMSCs. The present study revealed that passage (P) 1 cells cultured in osteogenic-induced medium showed strong positive staining for alkaline phosphatase (ALP) and Alizarin Red S, whereas P3 cells showed faint staining for ALP, with no Alizarin Red S staining. Staining of P1, P2 and P3 cells were progressively weaker, indicating that the osteogenic potential of the serially-passaged rat BMSCs is lost after P3 in vitro. The in vivo study showed that little bone formation was observed in the HA constructs seeded with P3 cells, 4 weeks after subcutaneous implantation. However, P3 cell/HA constructs which had increased cell-loading showed abundant bone formation within the pores of the HA construct. ALP and osteocalcin mRNA expression in these constructs was significantly higher than that of constructs with regular cell-seeding. The present study indicates that the osteogenic potential of the constructs with serially-passaged BMSCs is increased by additional cell-loading. This method can be applied to cases requiring hard tissue reconstruction, where BMSCs require serial expansion of cells.
基金part financed from Institutional grant KNW-1-010/P/1/0 and KNW-1-007/P/2/0 awarded to ALSco-financed by the EU funds(European Re-gional Development Fund)within the Sectoral Operational Program“Increase of Economic Competitiveness”No.WKP1/1.4/3/2/2005/103/223/565/2007/USilesian Bio-Farma Center for Biotechnology,Bioengineering and Bioinformatics,Project no POIG.02.01.00-00-166/08,THE OPERATIONAL PROGRAMME INNOVATIVE ECONOMY FOR 2007-2013,Priority Axis 2.R&D Infrastructure.
文摘The allogenic bone marrow derived mesenchymal stem cells transplantation was given to the newborn girl diagnosed with osteogenesis imperfecta type III, with multiple bone fractures, extreme shortness and limbs deformities. The treatment was performed at the age of 4 and 6 weeks. The clinical diagnosis was supported by biochemical analysis of collagen type I recovered from culture medium of cultivated patient’s skin fibroblast, which revealed its triple helix instability at temperature about 2?C lower than normal. Sequencing of both genes encoding procollagen type I revealed heterozygous substitution G23569Ain COL1A2 gene causing change of glycine at position 517 to aspartate. The donor of mesenchymal stem cells was the girl’s father. She received two intravenous infusions of suspended cultured mesenchymal cells in 16 days apart without any side effects. An analysis of procollagen type I secreted to the culture medium by bone marrow-derived mesenchymal stem cells obtained from the patient, 3 months following transplantation revealed its normal triple helix stability. During the subsequent two years of follow up two new bone fractures were noted. Currently a two-year-old girl’s presents extreme growth and weight deficiency. The motoric development is also retarded, but the patient constantly improves and makes progresses.
文摘Objective: skeletal advancement in order to improve the airway dimensions is known as one of the most effective surgical theraphy for treating obstructive sleep apnea (OSA). Distraction osteogenesis (DO) can be a better treatment alternative in some selected cases similar to our patient. Using custom made distractors can make this technique more safe and successful. Study Design: Surgically assisted rapid palatal expansion (SARPE), bilateral intraoral mandibular distraction osteogenesis (MDO) and orthodontic treatment were tried to a 20-year-old OSA patient with orthognathic anomaly. For mandibular distraction, custom made distractors were used. Results: The initial AHI of the patient was 23.3. At the end of the treatment it decreased to 8.7. Conclusions: Distraction osteogenesis could be a better alternative than the conventional orthognathic surgery in this kind of selected patients. Customization of the distraction devices can contribute to making this procedure safer and more successful.
文摘AIM To establish a hypoxic environment for promoting osteogenesis in rat marrow stromal cells(MSCs) using osteogenic matrix cell sheets(OMCSs).METHODS Rat MSCs were cultured in osteogenic media under one of four varying oxygen conditions: Normoxia(21% O_2) for 14 d(NN), normoxia for 7 d followed by hypoxia(5% O_2) for 7 d(NH), hypoxia for 7 d followed by normoxia for 7 d(HN), or hypoxia for 14 d(HH). Osteogenesis was evaluated by observing changes in cell morphology and calcium deposition, and by measuring osteocalcin secretion(ELISA) and calcium content. In vivo syngeneic transplantation using OMCSs and β-tricalcium phosphate discs, preconditioned under NN or HN conditions, was also evaluated by histology, calcium content measurements,and real-time quantitative PCR.RESULTS In the NN and HN groups, differentiated, cuboidal-shaped cells were readily observed, along with calcium deposits. In the HN group, the levels of secreted osteocalcin increased rapidly from day 10 as compared with the other groups, and plateaued at day 12(P < 0.05). At day 14, the HN group showed the highest amount of calcium deposition. In vivo, the HN group showed histologically prominent new bone formation, increased calcium deposition, and higher collagen type Ⅰ?messenger RNA expression as compared with the NN group.CONCLUSION The results of this study indicate that modifying oxygen tension is an effective method to enhance the osteogenic ability of MSCs used for OMCSs.
基金supported by the Traditional Chinese Medicine Research Fund of the Administration of Traditional ChineseMedicine of Shaanxi Province (jc34)
文摘Objective To investigate the histological changes of rapid tooth movement in dogs treated by resistance reduction and distraction osteogenesis,aiming to establish an animal model and further to reveal the remodeling mechanism of rapid tooth movement. Methods A total of 8 local hybrid dogs were selected as subjects for this study. The second pre-molar was extracted on both sides. The experimental side underwent alvelor surgery for resistance reduction and a home-made tooth-borne intraoral distraction device was installed for rapid tooth movement,while for the other side (control side) only tooth-borne intraoral distraction device was used for rapid tooth movement. The longest active force-delivery span was 2 weeks,followed by 6-week retention. The distance between the moved tooth and anchor unit was recorded weekly,and radiography was performed for each side before and after distraction. The surrounding tissues including periodontal ligament and alveolar bone were sectioned for histological analysis. Results The average distance of tooth movement was 3.55mm on the experimental side and 1.11mm on the control side. The rate of tooth movement was notably higher (P<0.01) and no significant apical root resorption was detected by X-ray on the experimental side. The active alvelor bone remodeling was found on the tension and pressure sides. However,there was no significant difference between the experimental side and the control side after the retention period. Conclusion The rate of orthodontic tooth movement can be accelerated through resistance reduction and periodontal distraction without any unfavorable effects but at minimal anchorage loss.
文摘Periodontitis,as a chronic inflammatory disease,remains unsolved,and the pathogenesis of this disease has not been fully elucidated.In this study,the effect of miR-4262 was investigated in tumor necrosis factor-α(TNF-α)induced human periodontal stem cells(hPDLSCs)for the first time.The gene expression involved in this study was determined using polymerase chain reaction(PCR),the expressions of relevant proteins were determined by western blot analysis,and the levels of IL-1β,IL-6,and MCP-1 were estimated by enzyme-linked immunosorbent assay(ELISA)assay.The luciferase reporter assay was performed for verification of the target gene,alkaline phosphatase(ALP)activity detection was used for differentiation capacity,and alizarin red staining assay was used for mineralization capacity.The inhibition of miRNA-4262,which resulted in the upregulation of suppressor of cytokine signaling 4(SOCS4),showed protective effects,including anti-inflammation and promotional effects on osteogenesis as well as differentiation in TNF-αinduced hPDLSCs.These results provided insights into the roles of miRNAs in regulating the inflammatory response,differentiation,and osteogenesis in hPDLSCs,which may promote the understanding of the mechanisms of periodontitis and find out a better therapeutic application.
