Introduction. Osteoporosis accounts for a major risk factor of fracture-associated disability or premature death in the elderly. Enhancement of bone anabolism for slowing osteoporosis is highly demanding. Exerkine fibronectin type III domain containing 5 (FNDC5) regulates energy metabolism, inflammation, and aging. This study was aimed to investigate whether Fndc5 signaling in osteoblasts changed estrogen deficiency-mediated bone loss or microarchitecture deterioration. Method. Female osteoblast-specific Fndc5 transgenic mice (Fndc5Tg), which overexpressed Fndc5 under the control of key osteoblast marker osteocalcin promoter, were given bilateral ovariectomy to induce estrogen deficiency-mediated osteoporosis. Bone mass, microstructures, and biomechanical properties were quantified using μCT imaging and material testing. Dynamic bone formation was traced using fluorescence calcein. Osteogenic differentiation and adipocyte formation of bone-marrow mesenchymal cells were investigated using von Kossa staining and Nile red staining, respectively. Serum osteocalcin, CTX-1 and TRAP5b levels were quantified using designated ELISA kits. Mitochondrial respiration was investigated using Seahorse Extracellular Flux Analyzer. Result. Fndc5Tg mice developed relatively higher bone mass and microarchitecture than wild-type mice. Fndc5 overexpression attenuated the losses of bone mineral density and trabecular network, including trabecular volume, thickness, and trabecular number, and improved cortical thickness and porosity in ovariectomized mice. Gain of Fndc5 function preserved biomechanical characteristics (maximum load, breaking force, and energy), serum bone formation marker osteocalcin levels, and bone formation rate, whereas it reduced serum
Introduction. The incidences of fragility fractures, often because of osteoporosis, are increasing. Research has moved towards bioresorbable scaffolds that provide temporary mechanical stability and promote osteogenesis. This research aims to fabricate a 3D printed composite Poly (l-lactic-co-glycolic acid)-strontium doped tricalcium phosphate (PLGA-SrTCP) scaffold and evaluate in an in vitro co culture study containing osteoporotic donor cells. Method. PLGA, PLGA TCP, and PLGA SrTCP scaffolds were produced using Fused Filament Fabrication (FFF). A four-group 35-day cell culture study was carried out using human bone marrow derived mesenchymal stem cells (hMSCs) from osteoporotic and control donors (monoculture) and hMSCs & human monocytes (hMCs) (Co culture). Outcome measures were biochemical assays, PCR, and cell imaging. Cells were cultured on scaffolds that had been pre-degraded for six weeks at 47°C prior to drying and gamma sterilisation. Result. 3D printed scaffolds were successfully produced by FFF. All groups in the study supported cell attachment onto the scaffolds, producing extracellular matrices as well as evidence of osteoclast cell structures. Osteoporotic cells increased CTSK activity and CAII activity and decreased ALP activity compared to controls. In control cultures, the addition of bTCP and bTCP/Sr to the PLGA reduced TRAP5b, CAII and ALP activity compared to PLGA alone. The addition of Sr did not show any differences between donors. Conclusion. This study details suitability of 3D printed polymer scaffolds for use in bone tissue applications. Both composite and pure polymer scaffolds promote osteogenesis in vitro. The introduction of ceramic filler and ion doping does not beneficially effect osteogenic potential and can reduce its ability compared to pure polymer. This study suggests the behaviour of control and osteoporotic cells are different and that osteoporotic cells are more prone to
The incidence of limb fractures in patients living with HIV (PLWH) is increasing. However, due to their immunodeficiency status, the operation and rehabilitation of these patients present unique challenges. Currently, it is urgent to establish a standardized perioperative rehabilitation plan based on the concept of enhanced recovery after surgery (ERAS). This study aimed to validate the effectiveness of ERAS in the perioperative period of PLWH with limb fractures. A total of 120 PLWH with limb fractures, between January 2015 and December 2023, were included in this study. We established a multidisciplinary team to design and implement a standardized ERAS protocol. The demographic, surgical, clinical, and follow-up information of the patients were collected and analyzed retrospectively.Aims
Methods
This multicentre retrospective observational study’s aims were to investigate whether there are differences in the occurrence of radiolucent lines (RLLs) following total knee arthroplasty (TKA) between the conventional Attune baseplate and its successor, the novel Attune S+, independent from other potentially influencing factors; and whether tibial baseplate design and presence of RLLs are associated with differing risk of revision. A total of 780 patients (39% male; median age 70.7 years (IQR 62.0 to 77.2)) underwent cemented TKA using the Attune Knee System) at five centres, and with the latest radiograph available for the evaluation of RLL at between six and 36 months from surgery. Univariate and multivariate logistic regression models were performed to assess associations between patient and implant-associated factors on the presence of tibial and femoral RLLs. Differences in revision risk depending on RLLs and tibial baseplate design were investigated with the log-rank test.Aims
Methods
This study examined the relationship between obesity (OB) and osteoporosis (OP), aiming to identify shared genetic markers and molecular mechanisms to facilitate the development of therapies that target both conditions simultaneously. Using weighted gene co-expression network analysis (WGCNA), we analyzed datasets from the Gene Expression Omnibus (GEO) database to identify co-expressed gene modules in OB and OP. These modules underwent Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment and protein-protein interaction analysis to discover Hub genes. Machine learning refined the gene selection, with further validation using additional datasets. Single-cell analysis emphasized specific cell subpopulations, and enzyme-linked immunosorbent assay (ELISA), protein blotting, and cellular staining were used to investigate key genes.Aims
Methods
Bone defects are frequently observed in anterior shoulder instability. Over the last decade, knowledge of the association of bone loss with increased failure rates of soft-tissue repair has shifted the surgical management of chronic shoulder instability. On the glenoid side, there is no controversy about the critical glenoid bone loss being 20%. However, poor outcomes have been described even with a subcritical glenoid bone defect as low as 13.5%. On the humeral side, the Hill-Sachs lesion should be evaluated concomitantly with the glenoid defect as the two sides of the same bipolar lesion which interact in the instability process, as described by the glenoid track concept. We advocate adding remplissage to every Bankart repair in patients with a Hill-Sachs lesion, regardless of the glenoid bone loss. When critical or subcritical glenoid bone loss occurs in active patients (> 15%) or bipolar off-track lesions, we should consider anterior glenoid bone reconstructions. The techniques have evolved significantly over the last two decades, moving from open procedures to arthroscopic, and from screw fixation to metal-free fixation. The new arthroscopic techniques of glenoid bone reconstruction procedures allow precise positioning of the graft, identification, and treatment of concomitant injuries with low morbidity and faster recovery. Given the problems associated with
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 osteogenesis. Crosstalk among macrophages, T cells, and MSCs affects the bone microenvironment and regulates the local immune response. Manipulating the proportion and interactions of these cells presents an opportunity to alter the local regenerative capacity of bone, which potentially could enhance clinical outcomes. Cite this article:
This study intended to investigate the effect of vericiguat (VIT) on titanium rod osseointegration in aged rats with iron overload, and also explore the role of VIT in osteoblast and osteoclast differentiation. In this study, 60 rats were included in a titanium rod implantation model and underwent subsequent guanylate cyclase treatment. Imaging, histology, and biomechanics were used to evaluate the osseointegration of rats in each group. First, the impact of VIT on bone integration in aged rats with iron overload was investigated. Subsequently, VIT was employed to modulate the differentiation of MC3T3-E1 cells and RAW264.7 cells under conditions of iron overload.Aims
Methods
This study explored the shared genetic traits and molecular interactions between postmenopausal osteoporosis (POMP) and sarcopenia, both of which substantially degrade elderly health and quality of life. We hypothesized that these motor system diseases overlap in pathophysiology and regulatory mechanisms. We analyzed microarray data from the Gene Expression Omnibus (GEO) database using weighted gene co-expression network analysis (WGCNA), machine learning, and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis to identify common genetic factors between POMP and sarcopenia. Further validation was done via differential gene expression in a new cohort. Single-cell analysis identified high expression cell subsets, with mononuclear macrophages in osteoporosis and muscle stem cells in sarcopenia, among others. A competitive endogenous RNA network suggested regulatory elements for these genes.Aims
Methods
Paget's disease of bone (PDB) is characterised by increased
Accurate diagnosis of chronic periprosthetic joint infection (PJI) presents a significant challenge for hip surgeons. Preoperative diagnosis is not always easy to establish, making the intraoperative decision-making process crucial in deciding between one- and two-stage revision total hip arthroplasty (THA). Calprotectin is a promising point-of-care novel biomarker that has displayed high accuracy in detecting PJI. We aimed to evaluate the utility of intraoperative calprotectin lateral flow immunoassay (LFI) in THA patients with suspected chronic PJI. The study included 48 THAs in 48 patients with a clinical suspicion of PJI, but who did not meet European Bone and Joint Infection Society (EBJIS) PJI criteria preoperatively, out of 105 patients undergoing revision THA at our institution for possible PJI between November 2020 and December 2022. Intraoperatively, synovial fluid calprotectin was measured with LFI. Cases with calprotectin levels ≥ 50 mg/l were considered infected and treated with two-stage revision THA; in negative cases, one-stage revision was performed. At least five tissue cultures were obtained; the implants removed were sent for sonication.Aims
Methods
The present study investigated receptor activator of nuclear factor kappa-Β ligand (RANKL), osteoprotegerin (OPG), and Runt-related transcription factor 2 (RUNX2) gene expressions in giant cell tumour of bone (GCTB) patients in relationship with tumour recurrence. We also aimed to investigate the influence of CpG methylation on the transcriptional levels of RANKL and OPG. A total of 32 GCTB tissue samples were analyzed, and the expression of RANKL, OPG, and RUNX2 was evaluated by quantitative polymerase chain reaction (qPCR). The methylation status of RANKL and OPG was also evaluated by quantitative methylation-specific polymerase chain reaction (qMSP).Aims
Methods
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. 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 osteogenesis in males, but not females, in the presence of chronic inflammation induced by cPE.
Although bone morphogenetic protein 2 (BMP-2) has been FDA-approved for spinal fusion for decades, its disadvantages of promoting osteoclast-based
Bone regeneration is pivotal for the healing of fractures. In case this process is disturbed a non-union can occur. This can be induced by environmental factors such as smoking, overloading etc. Co-morbidities such as diabetes, osteoporosis etc. may be more intrinsic factors besides other disturbances in the process. Those pathways negatively influence the bone regeneration process. Several intrinsic signal transduction pathways (WNT, BMP etc.) can be affected. Furthermore, on the transcriptional level, important mRNA expression can be obstructed by deregulated miRNA levels. For instance, several miRNAs have been shown to be upregulated during osteoporotic fractures. They are detrimental for osteogenesis as they block bone formation and accelerate
cAMP response element binding protein (CREB1) is involved in the progression of osteoarthritis (OA). However, available findings about the role of CREB1 in OA are inconsistent. 666-15 is a potent and selective CREB1 inhibitor, but its role in OA is unclear. This study aimed to investigate the precise role of CREB1 in OA, and whether 666-15 exerts an anti-OA effect. CREB1 activity and expression of a disintegrin and metalloproteinase with thrombospondin motifs 4 (ADAMTS4) in cells and tissues were measured by immunoblotting and immunohistochemical (IHC) staining. The effect of 666-15 on chondrocyte viability and apoptosis was examined by cell counting kit-8 (CCK-8) assay, JC-10, and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labelling (TUNEL) staining. The effect of 666-15 on the microstructure of subchondral bone, and the synthesis and catabolism of cartilage, in anterior cruciate ligament transection mice were detected by micro-CT, safranin O and fast green (S/F), immunohistochemical staining, and enzyme-linked immunosorbent assay (ELISA).Aims
Methods
Metabolic bone diseases, such as osteoporosis and osteopetrosis, result from an imbalanced bone remodeling process. In vitro bone models are often used to investigate either bone formation or resorption independently, while in vivo, these processes are coupled. Combining these processes in a co-culture is challenging as it requires finding the right medium components to stimulate each cell type involved without interfering with the other cell type's differentiation. Furthermore, differentiation stimulating factors often comprise growth factors in supraphysiological concentrations, which can overshadow the cell-mediated crosstalk and coupling. To address these challenges, we aimed to recreate the physiological bone remodeling process, which follows a specific sequence of events starting with cell activation and
Osteoporosis is a progressive, chronic disease of bone metabolism, characterized by decreased bone mass and mineral density, predisposing individuals to an increased risk of fractures. The use of animal models, which is the gold standard for the screening of anti-osteoporosis drugs, raises numerous ethical concerns and is highly debated because the composition and structure of animal bones is very different from human bones. In addition, there is currently a poor translation of pre-clinical efficacy in animal models to human trials, meaning that there is a need for an alternative method of screening and evaluating new therapeutics for metabolic bone disorders, in vitro. The aim of this project is to develop a 3D Bone-On-A-Chip that summarizes the spatial orientation and mutual influences of the key cellular components of bone tissue, in a citrate and hydroxyapatite-enriched 3D matrix, acting as a 3D model of osteoporosis. To this purpose, a polydimethylsiloxane microfluidic device was developed by CAD modelling, stereolithography and replica molding. The device is composed by two layers: (i) a bottom layer for a 3D culture of osteocytes embedded in an osteomimetic collagen-enriched matrigel matrix with citrate-doped hydroxyapatite nanocrystals, and (ii) a upper layer for a 2D perfused co-culture of osteoblasts and osteoclasts seeded on a microporous PET membrane. Cell vitality was evaluated via live/dead assay. Bone deposition and
Anatomically, bone consists of building blocks called osteons, which in turn comprise a central canal that contains nerves and blood vessels. This indicates that bone is a highly innervated and vascularized tissue. The function of vascularization in bone (development) is well-established: providing oxygen and nutrients that are necessary for the formation, maintenance, and healing. As a result, in the field of bone tissue engineering many research efforts take vascularization into account, focusing on engineering vascularized bone. In contrast, while bone anatomy indicates that the role of innervation in bone is equally important, the role of innervation in bone tissue engineering has often been disregarded. For many years, the role of innervation in bone was mostly clear in physiology, where innervation of a skeleton is responsible for sensing pain and other sensory stimuli. Unraveling its role on a cellular level is far more complex, yet more recent research efforts have unveiled that innervation has an influence on osteoblast and osteoclast activity. Such innervation activities have an important role in the regulation of bone homeostasis, stimulating bone formation and inhibiting resorption. Furthermore, due to their anatomical proximity, skeletal nerves and blood vessels interact and influence each other, which is also demonstrated by pathways cross-over and joint responses to stimuli. Besides those closely connected sytems, the immune system plays also a pivotal role in bone regeneration. Certain cytokines are important to attract osteogenic cells and (partially) inhibit
