Bone Abstracts

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-...

Objectives: To investigate the possible relationship between neonatal anthropometric characteristics and bone turnover and growth markers in a sample of neonates and their mothers, taking into account the size for the gestational age.Methods: A sample which consisted of 20 small for the gestational age (SGA), appropriate for the gestational age (AGA), and large for the gestational age (LGA) randomly selected term neonates and their 20 mothers were analyz...

Shwachman Diamond syndrome (SDS; MIM 260400) is a monogenic, autosomal recessive, pancreatic condition often accompanied by low bone mass and fracture. In SDS, as in cystic fibrosis, a low bone mass may be secondary to poor nutrition or chronic low-grade infection, but it has also been suggested there may be a primary bone phenotype. Paradoxically, recent studies in cell lines and in a mouse knockout for the SBDS gene, have suggested changes in important osteoclast gr...

Breast cancer (BrCa) patients with metastases restricted to bone (BO) show a longer overall survival compared to BrCa patients developing bone and visceral metastases (BV). To unveil the molecular mechanisms that segregate these two BrCa patient groups, we performed microarray analyses on bone metastasis samples from BO and BV patients, finding in the latter a set of up-regulated genes involved in oxygen metabolism. We focused on Hemoglobin B (HBB) and evaluated its expression...

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...

Strontium ranelate is a promising drug used in the treatment of osteoporosis. This drug has a unique dual effect on bone turnover, simultaneously increasing bone formation by osteoblasts (anabolic effect) and decreasing bone resorption by osteoclasts (antiresorptive effect). The goal of this study was to evaluate: i) anabolic effects of strontium ranelate on the formation of bone-like mineralized matrix in osteoblast cell cultures and ii) changes the drug could cause on the ma...

Mutations in PLEKHM1 cause bone disease in humans and animals. Truncations causedeficient bone resorption by osteoclasts leading to osteopetrosis. A gain-of-function point mutation causes increased resorption leading to osteopenia. We and others have shown that PLEKHM1, a multi-modular protein, interacts with the small GTPase rab7 and is involved in vesicle trafficking, secretion, and membrane biogenesis. To investigate other interactions of PLEKHM1 we performed tandem affinit...

RANKL, the receptor activator of nuclear factor kappa B ligand, is an essential factor for the formation of mature osteoclasts. Together with its receptor RANK and its antagonist Osteoprotegerin (OPG) RANKL is a key regulator in bone metabolism1. RANKL is a membrane-bound protein that can be segregated to a soluble form (sRANKL), whereas only the latter has been reported to be bioactive2. Due to its low circulating levels and the nature of the analyte bin...

Introduction: Wnt ligands bind to LDL receptor-related protein (LRP) 5 or −6, triggering a cascade of downstream events that include β-catenin signaling. Here, we explored the roles of LRP5 in interleukin (IL)-1β- or Wnt-mediated osteoarthritic (OA) cartilage destruction in mice.Methods: The expression levels of LRP5, Type II collagen, and catabolic factors were determined in mouse articular chondrocytes, human OA cartilage, and mouse exp...

Objective: The purpose of this study was to determine the impact of age on the ultrastructural, histological, biomechanical, and biochemical changes of bone tissue in rats.Methods: The study included 24 female rats of two age groups: Group A (Young) of 5-month old rats and Group B (Old) of 18-month old rats. Radiomorphometric assessment of the hydroxyapatite was used to investigate the ultrastructure of the alveolar bone tissue. Biomechanical and biochem...