Bone Abstracts

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...

Bisphosphonates (BPs) are widely used as antiresorptive drugs. However, one of most potent BPs, zoledronic acid (ZA) can cause BP-related osteonecrosis of the jaws (BRONJ) with a poorly understood pathophysiology. The aim of this study was to find a clue for the development of BRONJ by evaluating the cytotoxic effects of ZA on osteoblasts and examining the action mechanism of ZA on osteoclast differentiation. Jaw bone osteoblasts (JB-OBs), long bone osteoblasts (LB-OBs), and b...

Bone remodelling is maintained by a balanced activity of osteoclasts and osteoblasts. Alterations in this cross-talk result in bone pathological conditions. High bone mass defines a complex and heterogenous genetic condition characterized by increased bone density. In particular, osteopetrosis is a genetic condition of high bone mass caused by impairment in osteoclast generation or function. Molecular analysis of human osteopetrosis has allowed the identification of novel gene...

Bone regeneration and fracture healing processes are impaired in post menopausal osteoporosis which is induced by estrogen deficiency. Though agents like BMPs and PTH have been shown to promote bone regeneration but are associated with undesirable side effects. There is a need for new agents that enhance bone regeneration and repair.The aim of this study was to evaluate the bone regenerative capacity of medicarpin in the osteoporotic rat model. Cortical ...

Objective: GH through IGF1 plays an important role in both bone growth and mineralization. This cross-sectional study was carried out to evaluate the relationship between serum IGF1 concentrations and dual energy X-ray (DXA) measured total body less head (TB) bone area (BA), lean body mass (LBM) and bone mineral content (BMC).Methods: One hundred and nineteen children (B=70, age =7.3–15.6 years) were studied for their anthropometric paramet...