Bone Abstracts

Mineralized tissues like bone, articular calcified cartilage or mineralized turkey leg tendon (MTLT) are build by a composite of hydroxyapatite nano-particles and organic matrix. In bone and MTLT the matrix is formed by collagen type-I, but in contrast to bone in MTLT the collagen is uniaxial orientated, while in cartilage the matrix consists of collagen type-II and proteoglycans.Composition/orientation differences were investigated by a new scanning aco...

The local mechanical properties of bone are influenced not only by the material chemical composition but also by the spatial arrangement of the component’s e.g. orientation of collagen matrix. However, not much is known about local elastic modulus variations in cortical bone. Our goal was to use acoustic imaging to map elastic properties of murine bone with a several microns resolution. Rodent long bones exhibit a permanent growth with endosteal/periosteal bone formation ...

Introduction: Fracture risk is greater for adults with type 2 diabetes (T2D), despite normal or higher areal bone mineral density (aBMD) compared to controls. Tissue mineral density (TMD), measured by microCT, is more representative of actual mineral density than in vivo aBMD. The aim of this study was to determine whether TMD is greater in adults with T2D, and to investigate the correlates of TMD in adults with T2D.Methods: Using proximal femur...

Patients with chronic inflammatory diseases such as psoriasis are at high risk for developing osteoporosis. Psoriatic arthritis patients exhibit bone loss caused by increased bone resorption through activation of osteoclasts. However, it is not clear whether psoriasis can lead to bone loss in the absence of arthritis. Using mouse models with skin inflammation as well as psoriasis patient samples, we show that increased circulating IL-17A from the inflamed skin triggers bone lo...

Background: Osteocalcin has an important role in bone metabolism. Uncarboxylated osteocalcin predicts risk for hip fracture and lower bone mineral density (BMD). Warfarin inhibits carboxylation of osteocalcin, providing a mechanistic link between warfarin and impaired bone metabolism. Studies examining the relationship between warfarin use and BMD have been inconsistent. The goal of this study was to further characterize this relationship.Population: CaM...

Chondrosarcomas are cartilage-forming, poorly vascularized tumors. With an estimated annual incidence of 1 in 200 000, they represent the second malignant primary bone tumor of adults after osteosarcoma. These tumors are resistant to chemotherapy and radiotherapy, surgical excision remaining the only therapeutic option. However, very few cell lines and animal models are available, and the mechanisms behind their chemoresistance remain largely unknown. Our goal was to establish...

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Glucocorticoids (GCs) are widely used to treat chronic inflammatory diseases such as rheumatoid (RA) and lead to multiple side effects including glucocorticoid induced osteoporosis (GIO). Our work challenges the dogma that transrepression of pro-inflammatory genes by the glucocorticoid receptor (GR) is solely responsible for reducing inflammation, whereas transactivation of genes is causing side effects.Using conditional and function selective mutant mic...

Bone fractures of patients suffering from type 2 diabetes mellitus (T2DM) represent an emerging socioeconomic problem. Underling mechanisms are poorly understood and therapies are limited. Our previous studies have shown that sulfated hyaluronan (sHA3) suppresses osteoclast activity while supporting osteoblast function in vitro. Hence, we now investigated if sHA3 can improve the delayed fracture healing in rats with T2DM.Porous, cross-linked lactide-base...

Interleukin-34 (IL-34) is a newly discovered cytokine which regulates, like macrophage-colony stimulating factor (M-CSF), the differentiation/activation of the myeloid lineage. IL-34 and M-CSF are homodimers known to bind to the M-CSF receptor (M-CSFR) in a competitive manner. In this system, IL-34 can substitute for the M-CSF to induce osteoclastic differentiation. The aim of the present work was to study the functional relationships of these cytokines on cells expressing the...