Publications

Abstract OBJECTIVE To preclinically characterize a mutant form of growth and differentiation factor 5, R399E, with reduced osteogenic properties as a potential disease-modifying osteoarthritis (OA) drug. METHODS Cartilage, synovium, and meniscus samples from patients with OA were used to evaluate anabolic and antiinflammatory properties of R399E. In the rabbit joint instability model, 65 rabbits underwent […]

Abstract OBJECTIVES Here, we tested the hypothesis that human M-CSF (hM-CSF) overexpressed in cord blood (CB) CD34 cells would induce differentiation and survival of monocytes and osteoclasts in vitro and in vivo. METHODS Human M-CSF was overexpressed in cord blood CD34 cells using a lentiviral vector. RESULTS We show that LV-hM-CSF-transduced CB CD34 cells expand […]

Abstract Osteoclasts are multinuclear cells that degrade bone under both physiological and pathophysiological conditions. Osteoclasts are therefore a major target of osteoporosis therapeutics aimed at preserving bone. Consequently, analytical methods for osteoclast activity are useful for the development of novel biomarkers and/or pharmacological agents for the treatment of osteoporosis. The nucleation state of an osteoclast […]

Abstract OBJECTIVE Fibrotic diseases may be described as a disease of the extracellular matrix, where the balance between matrix formation and degradation has been shifted leading to an accumulation of matrix. Currently a fit for purpose model and readily available approach are adapted when doing cell cultures, which may not reflect physiology and pathophysiology optimally. […]

Abstract Osteoclasts are known to be important for the coupling process between bone resorption and formation. The aim of this study was to address when osteoclasts are anabolically active. Human monocytes were differentiated into mature osteoclasts by treatment with M-CSF and RANKL. Conditioned medium was collected from macrophages, pre-osteoclasts, and mature functional or non-resorbing osteopetrotic […]

Abstract Osteoclasts are multi-nucleated cells that have the unique ability to resorb calcified bone matrix. They derive from haematopoietic precursor cells, and can be generated in vitro by stimulation of peripheral blood mononuclear cells with the cytokines M-CSF and RANKL. In this chapter, we describe the method for generating human osteoclast from peripheral blood or […]

Abstract Bone development is dependent on the functionality of three essential cell types: chondrocytes, osteoclasts and osteoblasts. If any of these cell types is dysfunctional, a developmental bone phenotype can result. The bone disease osteopetrosis is caused by osteoclast dysfunction or impaired osteoclastogenesis, leading to increased bone mass. In ClC-7 deficient mice, which display severe […]

Abstract BACKGROUND Normal osteoclasts resorb bone by secretion of acid and proteases. Recent studies of patients with loss of function mutations affecting either of these processes have indicated a divergence in osteoclastic phenotypes. These difference in osteoclast phenotypes may directly or indirectly have secondary effects on bone remodeling, a process which is of importance for […]

Abstract Bone turnover is a highly regulated process, where bone resorption in the normal healthy individual always is followed by bone formation in a manner referred to as coupling. Patients with osteopetrosis caused by defective acidification of the resorption lacuna have severely decreased resorption, in face of normal or even increased bone formation. This suggests […]

Abstract UNLABELLED We investigated whether the age of the bones endogenously exerts control over the bone resorption ability of the osteoclasts, and found that osteoclasts preferentially develop and resorb bone on aged bone. These findings indicate that the bone matrix itself plays a role in targeted remodeling of aged bones. INTRODUCTION Osteoclasts resorb aging bone […]