Quantitative phenotyping of bone fracture repair: a review.
Ontology highlight
ABSTRACT:
SUBMITTER: Casanova M
PROVIDER: S-EPMC4119206 | biostudies-other | 2014
REPOSITORIES: biostudies-other
Similar Datasets
Project description:To further understand the molecular complexity of fracture repair, we investigated miRNA profiling during the first 14 days post fracture. miRNA expression was investigated at post-fracture days 1, 3, 5, 7, 11, 14 as well as in intact (unfractured bone).
2016-04-05 | E-GEOD-76197 | biostudies-arrayexpress
Project description:Bone formation in mammals requires continuous production of osteoblasts throughout life. A common molecular marker for all osteogenic mesenchymal progenitors has not been identified. Here, by lineage-tracing experiments in fetal or postnatal mice, we discover that Gli1+ cells progressively produce osteoblasts in all skeletal sites. Most notably, in postnatal growing mice, the Gli1+ cells residing immediately beneath the growth plate, termed here "metaphyseal mesenchymal progenitors" (MMPs), are essential for cancellous bone formation. Besides osteoblasts, MMPs also give rise to bone marrow adipocytes and stromal cells in vivo. RNA-seq reveals that MMPs express a number of marker genes previously assigned to mesenchymal stem/progenitor cells, including CD146/Mcam, CD44, CD106/Vcam1, Pdgfra, and Lepr. Genetic disruption of Hh signaling impairs proliferation and osteoblast differentiation of MMPs. Removal of ?-catenin causes MMPs to favor adipogenesis, resulting in osteopenia coupled with increased marrow adiposity. Finally, postnatal Gli1+ cells contribute to both chondrocytes and osteoblasts during bone fracture healing. Thus Gli1 marks mesenchymal progenitors responsible for both normal bone formation and fracture repair.
| S-EPMC5725597 | biostudies-literature
Project description:Bone fracture is accompanied by trauma, mechanical stresses, and inflammation - conditions known to induce the mitochondrial permeability transition. This phenomenon occurs due to opening of the mitochondrial permeability transition pore (MPTP) promoted by cyclophilin D (CypD). MPTP opening leads to more inflammation, cell death and potentially to disruption of fracture repair. Here we performed a proof-of-concept study and tested a hypothesis that protecting mitochondria from MPTP opening via inhibition of CypD improves fracture repair. First, our in vitro experiments indicated pro-osteogenic and anti-inflammatory effects in osteoprogenitors upon CypD knock-out or pharmacological inhibition. Using a bone fracture model in mice, we observed that bone formation and biomechanical properties of repaired bones were significantly increased in CypD knock-out mice or wild type mice treated with a CypD inhibitor, NIM811, when compared to controls. These effects were evident in young male but not female mice, however in older (13 month-old) female mice bone formation was also increased during fracture repair. In contrast to global CypD knock-out, mesenchymal lineage-specific (Prx1-Cre driven) CypD deletion did not result in improved fracture repair. Our findings implicate MPTP in bone fracture and suggest systemic CypD inhibition as a modality to promote fracture repair.
| S-EPMC7354230 | biostudies-literature
Project description:During endochondral fracture repair, a myriad of biochemical and phenotypic changes occur at the chondro-osseuous junction that regulate cartilage to bone conversion. Osteogenic and angiogenic factors have long been studied for accelerating fracture repair. In our concise study, we focused on the neurotrophic factor nerve growth factor (NGF) and its receptor tropomyosin receptor kinase A (TRKA) as understudied therapeutic targets for accelerating endochondral fracture repair. We first characterized endogenous expression of NGF and TRKA during endochondral repair of tibial fractures. We then analyzed gene expression data from β-NGF stimulated hypertrophic cartilage and observed a promotion in endochondral ossification associated markers. Additional gene ontology analyses revealed promotion of genes associated with Wnt activation, PDGF binding, and integrin binding. Subsequent histological analyses of in vivo samples confirmed Wnt activation following local β-NGF injections via reporter mice. Finally, we tested the therapeutic efficacy of local β-NGF injections in mice, which resulted in a decrease of cartilage and increase of bone volume. Moreover, the newly formed bone contained higher trabecular number, connective density, and bone mineral density. Collectively, we demonstrate the ability for β-NGF to promote endochondral fracture repair in a murine model and uncover mechanisms that will serve to further understand the molecular switches that occur during endochondral ossification.
2020-12-22 | GSE150092 | GEO
Project description:Adverse effects of spaceflight on musculoskeletal health increase the risk of bone injury and impairment of fracture healing. Its yet elusive molecular comprehension warrants immediate attention, since space travel is becoming more frequent. Here we examined the effects of spaceflight on bone fracture healing using a 2 mm femoral segmental bone defect (SBD) model. Forty, 9-week-old, male C57BL/6J mice were randomized into 4 groups: 1) Sham surgery on Ground (G-Sham); 2) Sham surgery housed in Spaceflight (FLT-Sham); 3) SBD surgery on Ground (G-Surgery); and 4) SBD surgery housed in Spaceflight (FLT-Surgery). Surgery procedures occurred 4 days prior to launch; post-launch, the spaceflight mice were house in the rodent habitats on the International Space Station (ISS) for approximately 4 weeks before euthanasia. Mice remaining on the Earth were subjected to identical housing and experimental conditions. The right femur from half of the spaceflight and ground groups was investigated by micro-computed tomography (µCT). In the remaining mice, the callus regions from surgery groups and corresponding femoral segments in sham mice were probed by global transcriptomic and metabolomic assays. µCT confirmed escalated bone loss in FLT-Sham compared to G-Sham mice. Comparing to their respective on-ground counterparts, the morbidity gene-network signal was inhibited in sham spaceflight mice but activated in the spaceflight callus. µCT analyses of spaceflight callus revealed increased trabecular spacing and decreased trabecular connectivity. Activated apoptotic signals in spaceflight callus were synchronized with inhibited cell migration signals that potentially hindered the wound site to recruit growth factors. A major pro-apoptotic and anti-migration gene network, namely the RANK-NFκB axis, emerged as the central node in spaceflight callus. Concluding, spaceflight suppressed a unique biomolecular mechanism in callus tissue to facilitate a failed regeneration, which merits a customized intervention strategy.
| S-EPMC8220416 | biostudies-literature
Project description:Spaceflight triggers molecular signal of apoptosis and inhibits cell migration to impede bone fracture repair in male mice Activated apoptosis and inhibited cell migration. Adverse impacts of spaceflight on musculoskeletal health increases the risk of bone fracture and impaired healing. Its yet elusive molecular comprehension warrants an immediate attention in the advent of increasingly frequent space travels. Here we examined the effect of spaceflight on bone healing using a 2mm femoral segmental bone defect (SBD) model. Forty, 9-week old, C57BL/6J male mice were randomized by cage into spaceflight or ground groups; 10 mice from spaceflight or ground groups, respectively underwent SBD surgery and rest served as unoperated sham controls. Surgery/sham procedures occurred 4 days prior to launch, thereafter the spaceflight mice were housed in the rodent habitat at International Space Station for around 4 weeks before their euthanasia. Feeding on same diet, the ground sham/surgery mice were in equivalent housing condition. The right leg femur from half of the spaceflight and ground groups were investigated by micro-computed tomography (µCT). In parallel, the callus regions from surgery groups and corresponding femoral segments in sham mice were probed by global transcriptomics and metabolomics assay. µCT confirmed escalated bone loss in sham spaceflight; and a concomitant trend towards habituation was highlighted by gene-metabolite networks linked to active cellular homeostasis and inhibited morbidity signal in sham spaceflight. The morbidity signal was switched in the spaceflight surgery mice and µCT analyses of spaceflight callus revealed an increased trabeculae spacing and decreased trabecular connectivity. Activated apoptotic signal in spaceflight callus was synchronized with inhibited cell migration signal that was critical for wounds to recruit growth factors, cytokines, and angiogenic agents. A major pro-apoptotic and anti-migration signal, namely RANK-NFκB axis emerged as the central node in spaceflight callus. Concluding, SBD in spaceflight triggered a unique biomolecular mechanism to meet failed regeneration, which merits a customized intervention strategy.
2021-06-30 | GSE161618 | GEO
Project description:BackgroundUse of recombinant human bone morphogenetic protein-2 (rhBMP-2) is expensive and may cause local side effects. A small synthetic molecule, SVAK-12, has recently been shown in vitro to potentiate rhBMP-2-induced transdifferentiation of myoblasts into the osteoblastic phenotype. The aims of this study were to test the ability of SVAK-12 to enhance bone formation in a rodent ectopic model and to test whether a single percutaneous injection of SVAK-12 can accelerate callus formation in a rodent femoral fracture model.MethodsCollagen disks with rhBMP-2 alone or with rhBMP-2 and SVAK-12 were implanted in a standard athymic rat chest ectopic model, and radiographic analysis was performed at four weeks. In a second set of rats (Sprague-Dawley), SVAK-12 was percutaneously injected into the site of a closed femoral fracture. The fractures were analyzed radiographically and biomechanically (with torsional testing) five weeks after surgery.ResultsIn the ectopic model, there was dose-dependent enhancement of rhBMP-2 activity with use of SVAK-12 at doses of 100 to 500 μg. In the fracture model, the SVAK-12-treated group had significantly higher radiographic healing scores than the untreated group (p = 0.028). Biomechanical testing revealed that the fractured femora in the 200 to 250-μg SVAK-12 group were 43% stronger (p = 0.008) and 93% stiffer (p = 0.014) than those in the control group. In summary, at five weeks the femoral fracture group injected with SVAK-12 showed significantly improved radiographic and biomechanical evidence of healing compared with the controls.ConclusionsA single local dose of a low-molecular-weight compound, SVAK-12, enhanced bone-healing in the presence of low-dose exogenous rhBMP-2 (in the ectopic model) and endogenous rhBMPs (in the femoral fracture model).Clinical relevanceThis study demonstrates that rhBMP-2 responsiveness can be enhanced by a novel small molecule, SVAK-12. Local application of anabolic small molecules has the potential for potentiating and accelerating fracture-healing. Use of this small molecule to lower required doses of rhBMPs might both decrease their cost and improve their safety profile.
| S-EPMC3748970 | biostudies-literature
Project description:Bone fracture is a growing public health burden and there is a clinical need for non-invasive therapies to aid in the fracture healing process. Previous studies have demonstrated the utility of electromagnetic (EM) fields in promoting bone repair; however, its underlying mechanism of action is unclear. Interestingly, there is a growing body of literature describing positive effects of an EM field on mitochondria. In our own work, we have previously demonstrated that differentiation of osteoprogenitors into osteoblasts involves activation of mitochondrial oxidative phosphorylation (OxPhos). Therefore, it was reasonable to propose that EM field therapy exerts bone anabolic effects via stimulation of mitochondrial OxPhos. In this study, we show that application of a low intensity constant EM field source on osteogenic cells in vitro resulted in increased mitochondrial membrane potential and respiratory complex I activity and induced osteogenic differentiation. In the presence of mitochondrial inhibitor antimycin A, the osteoinductive effect was reversed, confirming that this effect was mediated via increased OxPhos activity. Using a mouse tibial bone fracture model in vivo, we show that application of a low intensity constant EM field source enhanced fracture repair via improved biomechanical properties and increased callus bone mineralization. Overall, this study provides supporting evidence that EM field therapy promotes bone fracture repair through mitochondrial OxPhos activation.
| S-EPMC8476611 | biostudies-literature
Project description:IntroductionThe phases of fracture healing have been well characterized. However, the exact source and genetic profile of the skeletal progenitors that participate in bone repair is somewhat unclear. Sox9 expression in skeletal elements precedes bone and cartilage formation and a Sox9+ cell type is retained in the adult periosteum. We hypothesized that Sox9+ periosteal cells are multipotent skeletal progenitors normally participating in fracture repair.MethodsTo test this hypothesis we used tamoxifen (TM)-mediated lineage tracing of Sox9+ cells in Sox9CreErt2:Td-Tomato mice. Intact femora were analyzed with immunostaining and RNA sequencing to evaluate the skeletal distribution and gene expression profile of Td-Tomato positive, Sox9-descendent cells in the adult femur. To assess the role of Td-tomato+cells in the fracture healing process, mice underwent a closed mid-diaphyseal femoral fracture. Fractured hind limbs were analyzed by X-ray, histology and immuno-staining at 3, 9 or 56days post-fracture.ResultsIn the intact adult mouse femur, Td-Tomato-labeled cells were observed in the primary spongiosa, periosteum and endosteum. RNA sequencing showed that Td-Tomato positive periosteal cells were co-enriched for Sox9 transcripts, and mRNAs for osteoblast and chondrocyte specific genes. In a femoral fracture model, we showed that pre-labeled Td-Tomato positive descendent cells were mobilized during the early stages of bone repair (day 3 post-op) contributing to the fracture repair process by differentiating into chondrocytes, osteoblasts and osteocytes.ConclusionA Sox9+ skeletal progenitor population resides in the adult periosteum. Fate tracing studies show that descendants of the Sox9+ periosteal progenitors give rise to chondrocytes, osteoblasts and mature cortical osteocytes in repair of the fractured femur. To our knowledge this is the first report of a reparative Sox9+ progenitor population in the periosteum of the adult long bone. Taken together with developmental studies, our data suggest a broad role for Sox9+ osteochondroprogenitors in development and repair of the mammalian skeleton.
| S-EPMC6435293 | biostudies-literature
Project description:Diabetic bone defects may exhibit impaired endochondral ossification (ECO) leading to delayed bone repair. AdipoRon, a receptor agonist of adiponectin polymers, can ameliorate diabetes and related complications, as well as overcome the disadvantages of the unstable structure of artificial adiponectin polymers. Here, the effects of AdipoRon on the survival and differentiation of chondrocytes in a diabetic environment were explored focusing on related mechanisms in gene and protein levels. In vivo, AdipoRon was applied to diet-induced-obesity (DIO) mice, a model of obesity and type 2 diabetes, with femoral fracture. Sequential histological evaluations and micro-CT were examined for further verification. We found that AdipoRon could ameliorate cell viability, apoptosis, and reactive oxygen species (ROS) production and promote mRNA expression of chondrogenic markers and cartilaginous matrix production of ATDC5 cells in high glucose medium via activating ERK1/2 pathway. Additionally, DIO mice with intragastric AdipoRon administration had more neocartilage and accelerated new bone formation. These data suggest that AdipoRon could stimulate bone regeneration via ECO in diabetes.
| S-EPMC7722537 | biostudies-literature