Bone Abstracts

Osteoclasts secrete acid and cathepsin K to dissolve the mineral and digest the organic matrix of bone, cartilage and dentine. The secretions are by necessity destructive and potentially harmful to the cell itself and are therefore trafficked through the cell in membrane bound vesicles. Secretion takes place over a specialised membrane compartment, the ruffled border, which is only present in resorbing osteoclasts. The ruffled border membrane and the vesicles in its vicinity h...

The maintenance and adaptation of bone morphology results from orchestrated remodeling processes. These processes are locally coordinated by osteocytes with biochemical signals that result in increased or decreased bone formation or resorption activities. To better understand the morphology, we therefore have to understand how osteocytes determine dynamic morphometric parameters within their local microenvironment. Recently, a local in vivo environment (LivE)...

Objectives: Cross-sectional studies show that exercise may have positive effects on bone outcomes in youth. However, there is no evidence from longitudinal studies, which type of sports can induce improvements in bone acquisition in adolescent athletes. Therefore, this study aimed to investigate the longitudinal differences in bone acquisition and bone metabolism between adolescent males participating in osteogenic (football) and non-osteogenic (swimming, cycling) sports compa...

Sclerostin, a Wnt signaling antagonist encoded by the SOST gene, negatively regulates osteoblasts and inhibits bone formation. Mechanical loading, which induces bone formation, leads to a decrease in sclerostin levels. Recently, neutralizing antibodies against sclerostin were tested successfully for the treatment of osteoporosis in rodents. However, sclerostin is not the only signal involved in mechanotransduction. Therefore we investigated whether treatment with sclerostin an...

Peripheral quantitative computed tomography (pQCT) is receiving considerable attention in the diagnosis and monitoring of human bone diseases. It is well accepted that lower image resolution compared to micro-computed tomography (micro-CT) affects bone morphometry. With advances in micro-CT evaluation techniques such as sample-specific remodeling simulations or dynamic bone morphometry, there is the potential to also allow the application of such techniques to clinical pQCT sc...

Silk fibroin (SF) sponges are a promising scaffold material for tissue engineering due to their biocompatibility, mechanical properties, and ability to support calcium-phosphate formation in vitro. However, previous studies have shown that SF can mineralize spontaneously in the presence of culture media, which has a detrimental effect on experimental integrity when analyzing how cells deposit bone-like tissue in tissue engineering studies. In this study we analyzed th...

It is hypothesized that osteocytes regulate bone adaptation by sensing mechanical strains in their microenvironments and signaling net bone formation or resorption. Owing to bone’s anisotropic architecture, individual osteocytes within a bone experience varying strains under mechanical loading. Thus, to accurately determine the relationships between mechanical strain, osteocyte behavior, and bone remodeling, it is crucial to use a single-cell approach. Using an in viv...

Bone resorption and deposition occur in a tightly regulated fashion reflecting the coupled activities of osteoclasts and osteoblasts. Several pathological conditions perturb this balance between bone synthesis and resorption, including osteoporosis and skeletal metastases. The uncoupling of remodeling activities contributes to disseminated tumor cells homing to the bone and to tumor growth in bone. Therefore, a reliable marker of bone remodeling would be useful to provide a st...

Bone is continuously remodeled to remove damage, to adapt to changes in mechanical demands and to regulate calcium homeostasis. The first aim is accomplished by coupled bone formation and resorption whereas adaptation requires sites of formation to differ from those of resorption. The regulation of circulating ions is achieved by a stochastic exchange of bone packets. Here, we investigated these different aspects of remodeling in healthy and ovariectomized (OVX) mice treated w...

After trauma or carious lesion dental pulp healing is difficult to predict. In addition systemic diseases like diabetes mellitus can impair the regenerative capacity. New regenerative strategies target prolyl hydroxylase (PHD) by pharmacological inhibitors to stimulate hard and soft tissue healing. PHD inhibitors such as L-mimosine (L-MIM) induce vascular endothelial growth factor (VEGF) production by promoting angiogenesis. However, it is unclear if L-MIM is a feasible tool t...