Bone is a major storage site for TGFbeta superfamily members, including TGFbeta and bone morphogenetic proteins. It is believed that these cytokines are released from bone during bone resorption. Recent studies have shown that both RANKL and macrophage colony-stimulating factor are two essential factors produced by osteoblasts for inducing osteoclast differentiation. In the present study we exa...

Oats contain unique bioactive compounds known as avenanthramides (AVAs) with antioxidant properties. AVAs might enhance the endogenous antioxidant cellular response by activation of the transcription factor Nrf2. Accumulation of reactive oxygen species plays a critical role in many chronic and degenerative diseases, including osteoporosis. In this disease, there is an imbalance between bone for...

Studies on the immune regulation of osteoclasts in rheumatoid arthritis have promoted the new research field of 'osteoimmunology', which investigates the interplay between the skeletal and immune systems at the molecular level. Accumulating evidence lends support to the theory that bone destruction associated with rheumatoid arthritis is caused by the enhanced activity of osteoclasts, resulting...

In decalcified (5% nitric acid) and undecalcified (glycol-methacrylate or resin embedded) routinely processed bone specimens osteoclasts against resorbing surfaces were identified with monoclonal antibodies directed against leucocyte common antigen (LCA) (PD7/26, 2B11), CD68 (KP1), and gpIIIa (Y2/51) but not against HLA-DR (CR3/43 and Ta11B5). Mononuclear cells on resorbing surfaces and occasio...

Systemic acidosis is associated with bone loss and impaired bone mineralisation. The aim of this PhD project was to further investigate the action of extracellular pH on the function of osteoclasts and osteoblasts. I showed that blood-derived human osteoclasts exhibited a highly reproducible acid-activation response, with maximal activation close to pH 7.0, and little activity at blood pH (7.4)...

During the last two decades, ample evidence has been obtained that osteoclasts, the multinucleated calcified-matrix resorbing giant cells of bone, which form by fusion of mononuclear precursor cells, are of hematogenous origin. The evidence stems from experiments done in parabionts of labeled animals (1), studies on osteopetrotic animals and humans (2-4), and quail-chick and mouse-quail transpl...

Osteoclasts are multinucleated cells of hematopoietic origin and are the primary bone resorbing cells. Numerous osteoclasts are found within the synovial tissue at sites adjacent to bone, creating resorption pits and local bone destruction. They are equipped with specific enzymes and a proton pump that enable them to degrade bone matrix and solubilize calcium, respectively. The synovial tissue ...

We previously reported the transient appearance of an actin superstructure, called the zipper-like structure, during the primary fusion (fusion of mononuclear precursors) and the secondary fusion (fusion of multinucleated cells) of osteoclasts. Here, we focus on the actin-based superstructures that link two precursor cells during the secondary fusion event. In one type of secondary fusion, the ...