Bone Abstracts

Bone is a complex structure associating cells to an extracellular organic phase, including collagen and non collagenous proteins (NCPs), in close association with apatite mineral platelets. Although bone has given rise to extensive studies, the exact part played by NCPs in nucleating or inhibiting the mineral phase remains controversial. The present study aimed to better understand the functions of a major mineralizing protein, dentin matrix phosphoprotein 1 (DMP1), an acidic,...

The in vitro culture of calvarial osteoblasts from neonatal rodents remains an important method for studying the regulation of osteoblast function. Widespread use of transgenics has created a particular need for a reliable, simple method that allows the differentiation and bone-forming activity of mouse osteoblasts to be studied directly. We have established such a method and have identified key differences in optimal culture conditions between mouse and rat osteoblas...

In light of prolonged life expectancy, the need for biomaterials that govern bone regeneration increases. Improved bone regeneration and osseointegration can be achieved by funtionalizing implant materials. The extracellular matrix (ECM) affects differentiation of bone cells and is critical for bone regeneration. Here we assessed the role of the natural occurring bone ECM glycosaminoglycans (GAGs) hyaluronan (HA) and chondroitin sulfate (CS), and their sulfated derivatives, on...

Osteoclasts are produced by fusion of pre-osteoclasts derived from stem cells of the monocyte/macrophage lineage in the presence of receptor activator of NF-κB ligand (RANKL) produced by osteoblasts. The phytoestrogens; genistein and daidzein, which are isoflavones found in Leguminosae such as soybeans, are currently being investigated for prevention of postmenopausal osteoporosis. Some polyunsaturated fatty acids (PUFAs) have been shown to exert a bone protectiv...

RANKL induced osteoclastogenesis is mediated by several transcription factors such as NF-κB, AP-1 and Nfatc1. We have found that also cysteine proteinases are involved in the signaling pathway downstream RANK. Thus, cystatin C, Z-RLVG-CHN2 (the sequence of which is based upon one of the enzyme inhibitory domains in cystatin C) and the fungal molecule E-64 – inhibit RANKL induced mouse and human osteoclast formation in vitro (Strålberg et ...

Osteocytes differentiate from osteoblasts, are embedded in mineralised matrix and are critical regulators of bone remodelling. In vitro osteocyte models are limited to cell lines in monolayer, which do not represent their 3D environment in vivo. We have shown that osteoblasts in 3D gels differentiate along the osteocytic pathway. Since IGF1 regulates osteoblasts, and is involved in osteocyte response to mechanical loading, we hypothesised that IGF1 modulates ...

Surgical removal of the stomach (gastrectomy, Gx) leads to osteopenia in animals and in humans. In the rat, Gx causes loss of calvaria and trabecular bone, which can be reduced by 2-oxoglutaric acid (2-Ox), a precursor of hydroxyproline the most abundant amino acid in bone collagen. The purpose of this study was to investigate the effects (if any) of Gx on articular cartilage and if dietary 2-Ox can protects against eventual adverse effects of Gx. Twenty female Sprague–Da...

Our earlier results indicate that prenatal exposure to dexamethasone, synthetic glucocorticoid, may disturb metabolic processes in skeletal system with long-term consequences. Functional foods show a beneficial action that improve the state of health and reduce the risk of disease. The study was performed to determine whether 2-oxoglutaric acid (2-Ox) can abolish the growth inhibiting effect of prenatally administered dexamethasone (DEX) manifested in the growth plate and arti...

Indoxyl sulfate (IS) is one of a number of protein-bound uremic toxins that accumulate in patients with chronic kidney disease. Current conventional hemodialysis is ineffective at removing this toxin. Although IS may impair osteoblast function and induce abnormalities of bone turnover or arthropathy, the effects on knee joint tissue by IS has not been investigated yet. The present studies have been carried out to test the IS effects on synovial fibroblasts, meniscal fibrochond...

Purpose: Denosumab is a new potent antiresorptive treatment of osteoporosis that can potentially induce a compensatory increase of parathyroid hormone (PTH) levels. We aimed to evaluate the alteration of PTH 1 and 6 months after denosumab’s administration (60 mg) with different regimens of calcium and vitamin D (Ca/D) supplementation, as well as the association of PTH with serum Ca and bone markers.Methods: This was a prospective, multicenter, study...