Bone Abstracts

Introduction: Collagen and glycosaminoglycans (GAGs) such as hyaluronan (HA) and chondroitin sulfate (CS) are basic elements of bone structure and collagen-GAG composites are currently developed for a wide range of applications. Here, we report on the molecular and cellular effects of GAGs and their sulfated derivatives on osteocytes, which are fundamental orchestrators of bone remodeling.Materials and methods: The effects of native and sulfate-modified ...

The osteoclast-associated receptor (OSCAR), primarily described as a co-stimulatory regulator of osteoclast differentiation, represents a novel link between bone metabolism and vascular biology. Previously, we identified OSCAR on endothelial cells responding to the proatherogenic factor oxidized low density lipoprotein (oxLDL). Additionally, OSCAR expression was increased in the aorta of atherogenic apoE-knock-out (apoE-KO) mice, where it was further induced by feeding a high-...

Owing to their anti-inflammatory effects, steroid therapy using glucocorticoids (GCs) is still part of the treatment of rheumatoid arthritis (RA), despite several severe side effects like glucocorticoid-induced osteoporosis (GIO). Until now the molecular mechanisms underlying the beneficial and side effects of GC therapy are poorly understood. GCs exert their actions via the glucocorticoid receptor (GR) that alters gene expression by either binding as a dimer to GC response el...

Background: The tyrosine kinase inhibitor (TKI) imatinib is applied as front-line treatment in adult and pediatric patients with chronic myeloid leukemia (CML) in order to selectively inhibit the causative oncogenic BCR-ABL1 tyrosine kinase. However, TKIs exhibit off-target effects on further kinases involved in the regulation of bone metabolism. As consequence, pediatric patients display longitudinal growth retardation while on imatinib treatment. As CML is a rare disease in ...

Osteoporosis is a frequent disease leading to an increased risk of fractures caused by a systemic impairment of bone mass, strength, and microarchitecture. Given the emerging role of the Wnt signaling pathway in bone biology, we focused on the function of the important Wnt inhibitor dickkopf-1 (Dkk-1) and examined how the deletion of Dkk-1 solely in osteoblasts or osteocytes influences bone homeostasis. Therefore, we used the Cre-LoxP recombination system and crossed Dkk-1-flo...

Breast cancer is the most frequent malignancy in women and frequently results in osteolytic bone metastases. Amino-bisphosphonates are a standard bone protective therapy and, similarly to statins, inhibit the mevalonate pathway that is crucial for posttranslational protein modifications (farnesylation and geranylation). Direct anti-tumor effects of amino-bisphosphonates and statins have been suggested but high concentrations are necessary to achieve meaningful effects. Our stu...

Wnt proteins and their cognate receptors play a significant role in malignant diseases, in particular in prostate cancer (PCa). We previously showed that WNT5A inhibits PCa cell proliferation and induces apoptosis in vitro, leading to reduced PCa growth in vivo. However, the involved receptors remain unknown. Here, we determine the role of two Wnt receptors (FZD8, RYK) and their influence on the WNT5A-induced effects on PCa cells.The ex...

The pathogenesis of skeletal fragility in diabetes mellitus is poorly defined and efficient therapies are limited. Zucker diabetic fatty (ZDF) rats with type 2 diabetes mellitus display low bone mass and delayed bone defect healing. We tested whether intermittent treatment with human parathyroid hormone 1–84 (PTH) increases bone mass and bone defect regeneration in diabetic rats.A subcritical gap defect was created at the femur of 10 weeks old diabe...

Bone remodeling is a crucial process to maintain a healthy bone structure in order to avoid diseases like osteoporosis or osteopetrosis. Osteoclasts contribute to this process by resorbing old and brittle bone allowing osteoblasts to renew the bone substance. During resorption osteoclasts rearrange their actin cytoskeleton by forming an F-actin ring generating a resorptive cavity on the bone surface. Recently, we reported that the F-actin binding protein SWAP-70 regulates oste...

In light of prolonged life expectancy, the need for biomaterials that govern bone regeneration increases. Improved bone regeneration and osseointegration can be achieved by funtionalizing implant materials. The extracellular matrix (ECM) affects differentiation of bone cells and is critical for bone regeneration. Here we assessed the role of the natural occurring bone ECM glycosaminoglycans (GAGs) hyaluronan (HA) and chondroitin sulfate (CS), and their sulfated derivatives, on...