Bone Abstracts

see PP98....

Fracture healing is a multistep process that involves many cell lineages and is still not fully understood. We aimed to identify and characterize population of mesenchymal progenitor cells during its commitment within a fracture callus. To identify and trace cells in periosteum and bone marrow we used αSMA promoter-driven inducible Cre expression (αSMA-CreERT2) combined with a Cre-activated tdTomato reporter (Ai9) to generate αSMACre/Ai9 mice. Tibias, fixed with...

Rheumatoid arthritis (RA) is marked by the persistent inflammation and osteodestruction, causing progressive disability. Osteoclast progenitors (OCPs) represent a subpopulation of peripheral blood monocytes and have been shown to be present in healthy subjects and arthritic patients. The aim of our study was to determine the phenotype, frequency and osteoclastogenic potential of OCPs in the peripheral blood and synovial fluid of RA patients in response to anti-TNF therapy....

Introduction: Collagen induced arthritis (CIA) is a mouse model of rheumatoid arthritis marked by persistent inflammation and enhanced osteoresorption at the affected joints as well as systemic osteopenia due to increased activation of osteoclast progenitors (OCP). Abundantly secreted chemokines presumably attract OCPs to the inflamed sites. Our goal was to identify chemotactic signals important for OCPs recruitment in CIA.Methods: After obtaining approv...

Elevated levels of circulating serotonin have been reported to decrease bone mineral density1. Conversely, reduced serotonin (5HT) in mice lacking TPH1, the rate limiting enzyme for 5HT synthesis, was reported to be anabolic to the skeleton with high osteoblastic activity2. However, in other studies TPH1 deletion led to either an initial increase in BMD due to inhibition of osteoclastic bone resorption3, or had no bone effect4</su...

see PP68....

Pentraxin 3 (PTX3) is a highly conserved member of the long pentraxins subfamily produced in response to proinflammatory stimuli. Its biological roles have been associated to infection, female fertility and angiogenesis. We aimed to elucidate the role of PTX3 in the process of fracture healing.WT mice and mice deficient for the PTX3 gene (PTX3-KO) were used, after obtaining the approval from the Ethical committee. Cells from bone marrow and endosteal/per...

Rheumatoid arthritis (RA) is characterised by periarticular bone destruction leading to permanent disability. Some other forms of arthritis, such as arthritis in systemic lupus erythematosus (SLE), rarely produce bone lesions. Corresponding to that, inactivation of Fas produces a murine SLE-like phenotype, but alleviates bone loss during antigen-induced arthritis (AIA). Aim of this study was to identify cell populations differentially regulated in non-resorptive vs. resorptive...

To further characterize the role of serotonin (5HT) in bone metabolism, Wistar-Zagreb rat model consisting of the high-5HT and low-5HT subline with different platelet 5HT content and transporter (5HTT) activity has been used.Primary osteoclasts from the high-5HT subline had an increased expression of 5HTT, 5HT–2A receptor, Trap and cathepsin K, while osteoblasts showed no difference in the expression of 5HT elements or osteoblastic markers. However,...