To investigate the effects of senescent osteocytes on bone homeostasis in the progress of age-related osteoporosis and explore the underlying mechanism. In a series of in vitro experiments, we used tert-Butyl hydroperoxide (TBHP) to induce senescence of MLO-Y4 cells successfully, and collected conditioned medium (CM) and senescent MLO-Y4 cell-derived exosomes, which were then applied to MC3T3-E1 cells, separately, to evaluate their effects on osteogenic differentiation. Furthermore, we identified differentially expressed microRNAs (miRNAs) between exosomes from senescent and normal MLO-Y4 cells by high-throughput RNA sequencing. Based on the key miRNAs that were discovered, the underlying mechanism by which senescent osteocytes regulate osteogenic differentiation was explored. Lastly, in the in vivo experiments, the effects of senescent MLO-Y4 cell-derived exosomes on age-related bone loss were evaluated in male SAMP6 mice, which excluded the effects of oestrogen, and the underlying mechanism was confirmed.Aims
Methods
Aims. LY3023414 is a novel oral phosphatidylinositol 3-kinase (PI3K)/mammalian target of rapamycin (mTOR) dual inhibitor designed for advanced cancers, for which a phase II clinical study was completed in March 2020; however, little is known about its effect on bone modelling/remodelling. In this study, we aimed to explore the function of LY3023414 in bone modelling/remodelling. Methods. The function of LY3023414 was explored in the context of
Aims. Several artificial bone grafts have been developed but fail to achieve anticipated
Long non-coding RNAs (lncRNAs) are transcripts longer than 200 nucleotides with limited coding potential, which have emerged as novel regulators in many biological and pathological processes, including growth, development, and oncogenesis. Accumulating evidence suggests that lncRNAs have a special role in the osteogenic differentiation of various types of cell, including stem cells from different sources such as embryo, bone marrow, adipose tissue and periodontal ligaments, and induced pluripotent stem cells. Involved in complex mechanisms, lncRNAs regulate osteogenic markers and key regulators and pathways in osteogenic differentiation. In this review, we provide insights into the functions and molecular mechanisms of lncRNAs in
Bone is one of the most highly adaptive tissues in the body, possessing the capability to alter its morphology and function in response to stimuli in its surrounding environment. The ability of bone to sense and convert external mechanical stimuli into a biochemical response, which ultimately alters the phenotype and function of the cell, is described as mechanotransduction. This review aims to describe the fundamental physiology and biomechanisms that occur to induce osteogenic adaptation of a cell following application of a physical stimulus. Considerable developments have been made in recent years in our understanding of how cells orchestrate this complex interplay of processes, and have become the focus of research in
We describe two patients aged 16 and 25 years with
Objectives. Up to 10% of fractures result in undesirable outcomes, for which female sex is a risk factor. Cellular sex differences have been implicated in these different healing processes. Better understanding of the mechanisms underlying bone healing and sex differences in this process is key to improved clinical outcomes. This study utilized a macrophage–mesenchymal stem cell (MSC) coculture system to determine: 1) the precise timing of proinflammatory (M1) to anti-inflammatory (M2) macrophage transition for optimal bone formation; and 2) how such immunomodulation was affected by male versus female cocultures. Methods. A primary murine macrophage-MSC coculture system was used to demonstrate the optimal transition time from M1 to M2 (polarized from M1 with interleukin (IL)-4) macrophages to maximize matrix mineralization in male and female MSCs. Outcome variables included Alizarin Red staining, alkaline phosphatase (ALP) activity, and osteocalcin protein secretion. Results. We found that 96 hours of M1 phenotype in male cocultures allowed for maximum matrix mineralization versus 72 hours in female cocultures. ALP activity and osteocalcin secretion were also enhanced with the addition of IL-4 later in male versus female groups. The sex of the cells had a statistically significant effect on the optimal IL-4 addition time to maximize
Aims. Transcription factor nuclear factor kappa B (NF-κB) plays a major role in the pathogenesis of chronic inflammatory diseases in all organ systems. Despite its importance, NF-κB targeted drug therapy to mitigate chronic inflammation has had limited success in preclinical studies. We hypothesized that sex differences affect the response to NF-κB treatment during chronic inflammation in bone. This study investigated the therapeutic effects of NF-κB decoy oligodeoxynucleotides (ODN) during chronic inflammation in male and female mice. Methods. We used a murine model of chronic inflammation induced by continuous intramedullary delivery of lipopolysaccharide-contaminated polyethylene particles (cPE) using an osmotic pump. Specimens were evaluated using micro-CT and histomorphometric analyses. Sex-specific osteogenic and osteoclastic differentiation potentials were also investigated in vitro, including alkaline phosphatase, Alizarin Red, tartrate-resistant acid phosphatase staining, and gene expression using reverse transcription polymerase chain reaction (RT-PCR). Results. Local delivery of NF-κB decoy ODN in vivo increased
Aims. Bone regeneration during treatment of staphylococcal bone infection is challenging due to the ability of Staphylococcus aureus to invade and persist within osteoblasts. Here, we sought to determine whether the metabolic and extracellular organic matrix formation and mineralization ability of S. aureus-infected human osteoblasts can be restored after rifampicin (RMP) therapy. Methods. The human osteoblast-like Saos-2 cells infected with S. aureus EDCC 5055 strain and treated with 8 µg/ml RMP underwent osteogenic stimulation for up to 21 days. Test groups were Saos-2 cells + S. aureus and Saos-2 cells + S. aureus + 8 µg/ml RMP, and control groups were uninfected untreated Saos-2 cells and uninfected Saos-2 cells + 8 µg/ml RMP. Results. The S. aureus-infected osteoblasts showed a significant number of intracellular bacteria colonies and an unusual higher metabolic activity (p < 0.005) compared to uninfected osteoblasts. Treatment with 8 µg/ml RMP significantly eradicated intracellular bacteria and the metabolic activity was comparable to uninfected groups. The RMP-treated infected osteoblasts revealed a significantly reduced amount of mineralized extracellular matrix (ECM) at seven days
Study of 16 patients with Type III
Objectives. Many in vitro studies have investigated the mechanism by which mechanical signals are transduced into biological signals that regulate bone homeostasis via periodontal ligament fibroblasts during orthodontic treatment, but the results have not been systematically reviewed. This review aims to do this, considering the parameters of various in vitro mechanical loading approaches and their effects on osteogenic and osteoclastogenic properties of periodontal ligament fibroblasts. Methods. Specific keywords were used to search electronic databases (EMBASE, PubMed, and Web of Science) for English-language literature published between 1995 and 2017. Results. A total of 26 studies from the 555 articles obtained via the database search were ultimately included, and four main types of biomechanical approach were identified. Compressive force is characterized by static and continuous application, whereas tensile force is mainly cyclic. Only nine studies investigated the mechanisms by which periodontal ligament fibroblasts transduce mechanical stimulus. The studies provided evidence from in vitro mechanical loading regimens that periodontal ligament fibroblasts play a unique and dominant role in the regulation of bone remodelling during orthodontic tooth movement. Conclusion. Evidence from the reviewed studies described the characteristics of periodontal ligament fibroblasts exposed to mechanical force. This is expected to benefit subsequent research into periodontal ligament fibroblasts and to provide indirectly evidence-based insights regarding orthodontic treatment. Further studies should be performed to explore the effects of static tension on cytomechanical properties, better techniques for static compressive force loading, and deeper analysis of underlying regulatory systems. Cite this article: M. Li, C. Zhang, Y. Yang. Effects of mechanical forces on
Objectives. As one of the heat-stable enterotoxins, Staphylococcal enterotoxin C2 (SEC2) is synthesized by Staphylococcus aureus, which has been proved to inhibit the growth of tumour cells, and is used as an antitumour agent in cancer immunotherapy. Although SEC2 has been reported to promote osteogenic differentiation of human mesenchymal stem cells (MSCs), the in vivo function of SCE2 in animal model remains elusive. The aim of this study was to further elucidate the in vivo effect of SCE2 on fracture healing. Materials and Methods. Rat MSCs were used to test the effects of SEC2 on their proliferation and osteogenic differentiation potentials. A rat femoral fracture model was used to examine the effect of local administration of SEC2 on fracture healing using radiographic analyses, micro-CT analyses, biomechanical testing, and histological analyses. Results. While SEC2 was found to have no effect on rat MSCs proliferation, it promoted the osteoblast differentiation of rat MSCs. In the rat femoral fracture model, the local administration of SEC2 accelerated fracture healing by increasing fracture callus volumes, bone volume over total volume (BV/TV), and biomechanical recovery. The SEC2 treatment group has superior histological appearance compared with the control group. Conclusion. These data suggest that local administration of SEC2 may be a novel therapeutic approach to enhancing bone repair such as fracture healing. Cite this article: T. Wu, J. Zhang, B. Wang, Y. Sun, Y. Liu, G. Li. Staphylococcal enterotoxin C2 promotes
Bone regeneration and repair are crucial to ambulation and quality of life. Factors such as poor general health, serious medical comorbidities, chronic inflammation, and ageing can lead to delayed healing and nonunion of fractures, and persistent bone defects. Bioengineering strategies to heal bone often involve grafting of autologous bone marrow aspirate concentrate (BMAC) or mesenchymal stem cells (MSCs) with biocompatible scaffolds. While BMAC shows promise, variability in its efficacy exists due to discrepancies in MSC concentration and robustness, and immune cell composition. Understanding the mechanisms by which macrophages and lymphocytes – the main cellular components in BMAC – interact with MSCs could suggest novel strategies to enhance bone healing. Macrophages are polarized into pro-inflammatory (M1) or anti-inflammatory (M2) phenotypes, and influence cell metabolism and tissue regeneration via the secretion of cytokines and other factors. T cells, especially helper T1 (Th1) and Th17, promote inflammation and osteoclastogenesis, whereas Th2 and regulatory T (Treg) cells have anti-inflammatory pro-reconstructive effects, thereby supporting
Basilar impression is a well-recognised though rare complication of
Osteogenesis imperfecta is a rare inherited disorder of connective tissue which may present with recurrent fractures which are prone to nonunion and malunion resulting in deformity. Some patients develop osteoarthritis of the hip. Formation of hyperplastic callus after recurrent fractures may deform the shape of the femur and preclude the use of standard implants at joint replacement. Replacement can thus be technically demanding. We present a case of bilateral hip replacement in a patient with
We investigated the fracture-free survival of long bones stabilised by a telescopic intramedullary rod (TIMR) in patients with
We report the results of using 83 expanding intramedullary rods in 24 children with
Aims. The aim of this study was to determine the fracture haematoma (fxH) proteome after multiple trauma using label-free proteomics, comparing two different fracture treatment strategies. Methods. A porcine multiple trauma model was used in which two fracture treatment strategies were compared: early total care (ETC) and damage control orthopaedics (DCO). fxH was harvested and analyzed using liquid chromatography-tandem mass spectrometry. Per group, discriminating proteins were identified and protein interaction analyses were performed to further elucidate key biomolecular pathways in the early fracture healing phase. Results. The early fxH proteome was characterized by immunomodulatory and osteogenic proteins, and proteins involved in the coagulation cascade. Treatment-specific proteome alterations were observed. The fxH proteome of the ETC group showed increased expression of pro-inflammatory proteins related to, among others, activation of the complement system, neutrophil functioning, and macrophage activation, while showing decreased expression of proteins related to
We used dual-energy X-ray absorptiometry (DEXA) to compare the bone mineral density (BMD) of nine children aged from 2 years 7 months to 13 years 5 months who had mild
A survey was conducted to document the results of bracing and spinal fusion for scoliosis associated with
Paraplegia occurred in an adolescent girl with
Three cases of severe
We describe two patients with
We obtained specimens of growth-plate cartilage from four patients with
This paper describes the design, development and early surgical experience with a stereotactic device to allow closed retrieval and interchange of intramedullary rods in children with
We performed limb lengthening and correction of deformity of nine long bones of the lower limb in six children (mean age, 14.7 years) with
This paper examines the fate of decalcified allografts (homografts) of iliac cancellous bone impregnated with autologous red marrow and implanted intermuscularly into the anterior abdominal wall of rabbits. In contrast to the findings of Urist and other workers that cortical bone decalcified with hydrochloric acid (HCl) and then freeze-dried is inductive to new bone formation in various heterotopic sites, evidence is presented that iliac bone decalcified by HCl and grafted alone to a muscular site is itself very weakly inductive to bone formation. However, when combined with autologous bone marrow the HCl-decalcified bone provides a better substrate for bone formation by marrow cells than does either undecalcified iliac bone, or iliac bone decalcified with ethylene-diamine-tetra-acetic acid. The freezing or freeze-drying of decalcified bone does not affect new bone formation when implanted alone or with autologous marrow. The differences between the cortical and cancellous bone as inductive substrates for
The Sheffield Expanding Intramedullary Rod System was developed after experiencing problems with existing rod systems in the management of
The results and complications of the use of Bailey-Dubow extensible rods in 28 lower limb bones of 10 patients suffering from
Cite this article:
Long non-coding RNAs (lncRNAs) act as crucial regulators in osteoporosis (OP). Nonetheless, the effects and potential molecular mechanism of lncRNA PCBP1 Antisense RNA 1 (PCBP1-AS1) on OP remain largely unclear. The aim of this study was to explore the role of lncRNA PCBP1-AS1 in the pathogenesis of OP. Using quantitative real-time polymerase chain reaction (qRT-PCR), osteogenesis-related genes (alkaline phosphatase (ALP), osteocalcin (OCN), osteopontin (OPN), and Runt-related transcription factor 2 (RUNX2)), PCBP1-AS1, microRNA (miR)-126-5p, group I Pak family member p21-activated kinase 2 (PAK2), and their relative expression levels were determined. Western blotting was used to examine the expression of PAK2 protein. Cell Counting Kit-8 (CCK-8) assay was used to measure cell proliferation. To examine the osteogenic differentiation, Alizarin red along with ALP staining was used. RNA immunoprecipitation assay and bioinformatics analysis, as well as a dual-luciferase reporter, were used to study the association between PCBP1-AS1, PAK2, and miR-126-5p.Aims
Methods
Distraction osteogenesis (DO) is a useful orthopaedic procedure employed to lengthen and reshape bones by stimulating bone formation through controlled slow stretching force. Despite its promising applications, difficulties are still encountered. Our previous study demonstrated that pulsed electromagnetic field (PEMF) treatment significantly enhances bone mineralization and neovascularization, suggesting its potential application. The current study compared a new, high slew rate (HSR) PEMF signal, with different treatment durations, with the standard Food and Drug Administration (FDA)-approved signal, to determine if HSR PEMF is a better alternative for bone formation augmentation. The effects of a HSR PEMF signal with three daily treatment durations (0.5, one, and three hours/day) were investigated in an established rat DO model with comparison of an FDA-approved classic signal (three hrs/day). PEMF treatments were applied to the rats daily for 35 days, starting from the distraction phase until termination. Radiography, micro-CT (μCT), biomechanical tests, and histological examinations were employed to evaluate the quality of bone formation.Aims
Methods
We have reviewed the results of the Sofield-Millar operation on 58 long bones in ten patients. If more than three osteotomies were undertaken the time to union of the bone was significantly prolonged (p<
0.001) with significant thinning of the bone (p<
0.02). We have used a modified technique in order to minimise surgical trauma and devascularisation of the bone. The rod is introduced under the control of an image-intensifier. Small surgical exposures are made only at the sites of corrective wedge osteotomies. The number of osteotomies is kept to the minimum.
Distraction osteogenesis with intramedullary lengthening devices has undergone rapid development in the past decade with implant enhancement. In this first single-centre matched-pair analysis we focus on the comparison of treatment with the PRECICE and STRYDE intramedullary lengthening devices and aim to clarify any clinical and radiological differences. A single-centre 2:1 matched-pair retrospective analysis of 42 patients treated with the STRYDE and 82 patients treated with the PRECICE nail between May 2013 and November 2020 was conducted. Clinical and lengthening parameters were compared while focusing radiological assessment on osseous alterations related to the nail’s telescopic junction and locking bolts at four different stages.Aims
Methods
Aims. The use of 3D-printed titanium implant (DT) can effectively guide bone regeneration. DT triggers a continuous host immune reaction, including macrophage type 1 polarization, that resists osseointegration. Interleukin 4 (IL4) is a specific cytokine modulating osteogenic capability that switches macrophage polarization type 1 to type 2, and this switch favours bone regeneration. Methods. IL4 at concentrations of 0, 30, and 100 ng/ml was used at day 3 to create a biomimetic environment for bone marrow mesenchymal stromal cell (BMMSC)
Various approaches have been implemented to enhance bone regeneration, including the utilization of autologous platelet-rich plasma and bone morphogenetic protein-2. The objective of this study was to evaluate the impact of Marburg Bone Bank-derived bone grafts in conjunction with platelet-rich plasma (PRP), recombinant human bone morphogenetic protein-2 (rhBMP-2), and zoledronic acid (ZA) on
Bone regeneration is an area of acute medical need, but its clinical success is hampered by the need to ensure rapid vascularization of osteogenic grafts. Vascular Endothelial Growth Factor (VEGF) is the master regulator of vascular growth and during bone development angiogenesis and
Osteoarthritis (OA) is a chronic degenerative joint disease characterized by progressive cartilage degradation, synovial membrane inflammation, osteophyte formation, and subchondral bone sclerosis. Pathological changes in cartilage and subchondral bone are the main processes in OA. In recent decades, many studies have demonstrated that activin-like kinase 3 (ALK3), a bone morphogenetic protein receptor, is essential for cartilage formation,
Aim. Bone regeneration following the treatment of Staphylococcal bone infection or osteomyelitis is challenging due to the ability of Staphylococcus aureus to invade and persist within bone cells, which could possibly lead to antimicrobial tolerance and incessant bone destruction. Here, we investigated the influence of Staphylococcal bone infection on osteoblasts metabolism and function, with the underlying goal of determining whether Staphylococcus aureus-infected osteoblasts retain their ability to produce extracellular mineralized organic matrix after antibiotic treatment. Method. Using our in vitro infection model, human osteoblasts-like Saos-2 cells were infected with high-grade Staphylococcus aureus EDCC 5055 strain, and then treated with 8 µg/ml rifampicin and osteogenic stimulators up to 21-days. Results. Immunofluorescence and transmission electron microscopic (TEM) imaging demonstrated the presence of intracellular bacteria within the infected osteoblasts as early as 2 hours post-infection. TEM micrographs revealed intact intracellular bacteria with dividing septa indicative of active replication. The infected osteoblasts showed significant amounts of intracellular bacteria colonies and alteration in metabolic activity compared to the uninfected osteoblasts (p≤0.001). Treatment of S. aureus-infected osteoblasts with a single dose of 8 µg/ml rifampicin sufficiently restored the metabolic activity comparative to the uninfected groups. Alizarin red staining and quantification of the rifampicin-treated infected osteoblasts revealed significantly lower amount of mineralized extracellular matrix after 7-days
Stem cell therapy is an effective means to address the repair of large segmental bone defects. However, the intense inflammatory response triggered by the implants severely impairs stem cell differentiation and tissue regeneration. High-dose transforming growth factor β1 (TGF-β1), the most locally expressed cytokine in implants, inhibits osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) and promotes tissue fibrosis, severely compromising the efficacy of stem cell therapy. Small molecule inhibitors of TGF-β1 can be used to ameliorate the osteogenic disorders caused by high concentrations of TGF-β1, but systemic inhibition of TGF-β1 function will cause strong adverse effects. How to find safe and reliable molecular targets to antagonize TGF-β1 remains to be elucidated. Orphan nuclear receptor Nr4a1, an endogenous inhibitory molecule of TGF-β1, suppresses tissue fibrosis, but its role in BMSC
In 2021 the bone grafting market was worth €2.72 billion globally. As allograft bone has a limited supply and risk of disease transmission, the demand for synthetic grafting substitutes (BGS) continues to grow while allograft bone grafts steadily decrease. Synthetic BGS are low in mechanical strength and bioactivity, inspiring the development of novel grafting materials, a traditionally laborious and expensive process. Here a novel BGS derived from sustainably grown coral was evaluated. Coral-derived scaffolds are a natural calcium carbonate bio-ceramic, which induces
Osteomyelitis is an inflammatory condition accompanied by the destruction of bone and caused by an infecting microorganism. Open contaminated fractures can lead to the development of osteomyelitis of the fractured bone in 3-25% of cases, depending on fracture type, degree of soft-tissue injury, degree of microbial contamination, and whether systemic and/or local antimicrobial therapies have been administered. Untreated, infection will ultimately lead to non-union, chronic osteomyelitis, or amputation. We report a case series of 10 patients that presented with post-operative infected non-union of the distal femur with or without prior surgery. The cases were performed at Padmashree Dr. D. Y. Patil Hospital, Nerul, Navi Mumbai, India. All the patients’ consents were taken for the study which was carried out in accordance with the Helsinki Declaration. The methodology involved patients undergoing a two-stage procedure in case of no prior implant or a three-stage procedure in case of a previous implant. Firstly, debridement and implant removal were done. The second was a definitive procedure in form of knee arthrodesis with ring fixator and finally followed by limb lengthening surgery. Arthrodesis was planned in view of infection, non-union, severe arthritic, subluxated knee, stiff knee, non-salvage knee joint, and financial constraints. After all the patients demonstrated wound healing in 3 months along with good radiographic
There is still no consensus on which concentration of mesenchymal stem cells (MSCs) to use for promoting fracture healing in a rat model of long bone fracture. To assess the optimal concentration of MSCs for promoting fracture healing in a rat model. Wistar rats were divided into four groups according to MSC concentrations: Normal saline (C), 2.5 × 106 (L), 5.0 × 106 (M), and 10.0 × 106 (H) groups. The MSCs were injected directly into the fracture site. The rats were sacrificed at 2 and 6 자 post-fracture. New bone formation [bone volume (BV) and percentage BV (PBV)] was evaluated using micro-computed tomography (CT). Histological analysis was performed to evaluate fracture healing score. The protein expression of factors related to MSC migration [stromal cell-derived factor 1 (SDF-1), transforming growth factor-beta 1 (TGF-β1)] and angiogenesis [vascular endothelial growth factor (VEGF)] was evaluated using western blot analysis. The expression of cytokines associated with
Aims. It is increasingly appreciated that coordinated regulation of angiogenesis and
Aims. Here we introduce a wide and complex study comparing effects of growth factors used alone and in combinations on human mesenchymal stem cell (hMSC) proliferation and osteogenic differentiation. Certain ways of cell behaviour can be triggered by specific peptides – growth factors, influencing cell fate through surface cellular receptors. Methods. In our study transforming growth factor β (TGF-β), basic fibroblast growth factor (bFGF), hepatocyte growth factor (HGF), insulin-like growth factor 1 (IGF-1), and vascular endothelial growth factor (VEGF) were used in order to induce
Chronic glucocorticoid use causes
Glucocorticoid excess is shown to deteriorate bone tissue integrity, increasing the risk of osteoporosis. Marrow adipogenesis at cost of
Recently, technologies to culture one or more cell types in three dimensions have attracted a great deal of attention in tissue engineering. Particularly, the improved viability, self-renewal capacity, and differentiation potential have been reported for stem cell spheroids. However, it is crucial to modulate spheroid functions with instructive signals to use multi-cellular spheroids in tissue engineering. We have been developing ECM-mimicking fibrous materials decorated with cell-instructive cues, which were incorporated within 3D stem cell spheroids to fine-tune their functions as modular building blocks for bottom-up tissue-engineering applications. In particular, we created composite spheroids of human adipose-derived stem cells (hADSCs) incorporating nanofibers coated with instructive signal of either transforming growth factor-β3 or bone morphogenetic growth factor-2 for chondrogenesis or
3D Printed polyether-ether-ketone (PEEK) has gained widespread use in clinical practice due to its excellent biocompatibility, biomechanical compatibility, and personalization. However, pre-printed PEEK implants are not without their flaws, including bioinert, optimization distortion of 3D printing digital model and prosthetic mismatching. Recent advancements in mechanical processing technology have made it possible to print bone implants with PEEK fused deposition, allowing for the construction of mechanically adaptable implants. In this study, we aimed to synthesize silanized polycitrate (PCS) via thermal polymerization and in situ graft it to PEEK surface to construct an elastomer coating for 3D printed PEEK implants (PEEK-PCS). This incorporation of PCS allows the implant to exhibit adaptive space filling ability and stress dispersal. In vivo and in vitro results, PEEK-PCS exhibited exceptional osseointegration and