Bone Abstracts

Interleukin-6 (IL-6) plays an important role in bone metabolism and regulates fracture healing in a presently unknown process. In the fracture callus IL-6 expression is biphasic; it peaks during the inflammatory phase and again during intramembranous and endochondral ossification (Ai-Aql et al. 2008). Few studies using IL-6 knockout mice indicate that IL-6 might be crucial for bone healing (Yang et al. 2007). However, a generalized IL-6 knockout induces multi...

Previous studies demonstrated a negative influence of the growth- and differentiation factor midkine (MDK) on bone formation during bone remodeling and fracture healing. Additionally, MDK-deficiency protected mice from a loss of trabecular bone mass after ovariectomy (OVX). Therefore, we hypothesized that MDK may also be involved in the pathogenesis of delayed, osteoporotic fracture healing after OVX in mice. Thus, we analyzed the expression of MDK during bone regeneration and...

We used atomic force microscopy (AFM) to study the morphology and development of mineralization-competent matrix vesicles (MVs) secreted by chondrocytes isolated from WT and Phospho1−/− mice in order to validate the role of PHOSPHO1 in MV mineralization. All MVs appeared as flattened globular features either individually dispersed or connected to a mat-like structure. The mat-like structure very closely resembled type-X collagen that has been de...

The mammalian circadian clock is tightly controlled by clock genes, which have been shown to regulate up to 20% of the transcriptome in any given tissue. Evidence is accumulating that light-modulation perpetually affects circadian clock performance. In accordance, shift work or chronic jet lag is associated with higher risk of disease later in life, including osteoporosis. In this study, we assessed whether gestational jet lag in mice reduces bone mass postnatally.<p class...

Purpose: The aim of this research was to develop an in vivo platform for conveniently examining the potential of various factors to augment chondral bone regeneration. For this purpose, we have established a de novo partial tail amputation model in adult zebrafish, which includes the resection of cartilage-template based bones from the endoskeletal caudal complex. Endoskeletal amputations were rarely studied, as opposed to those of the distal caudal fin rays, a well-e...

Non-healing fractures caused by trauma, disease or tumour resection demand the use of bone grafts to support and stimulate the healing process. We sought to develop and evaluate the effect of a novel bioactive biodegradable biomaterial designed to fill large bone lesions and to improve bone healing. We used two-photon polymerised synthetic polymer scaffolds composed of lactide (LA), caprolactone (CL), and methacrylate (MA) with varying LA: CL ratio and percentage of methacryla...

Osteogenesis imperfecta (OI) type VI is caused by recessive null mutations in SERPINF1, encoding pigment epithelium-derived factor (PEDF), an anti-angiogenic secretory glycoprotein. Dominant mutations in IFITM5, encoding BRIL (Bone Restricted Ifitm-Like), a transmembrane protein upregulated in osteoblasts during mineralization, cause either type V OI (c.-14C>T, addition of 5 amino acids on BRIL) or atypical type VI OI (...

Reduced peripheral serotonin (5HT) in mice lacking tryptophan hydroxylase (TPH1), the rate limiting enzyme for 5HT synthesis, was reported to be anabolic to the skeleton. However, in other studies, TPH1 deletion either had no bone effect or an age-dependent inhibition of osteoclastic bone resorption. The role of 5HT in bone therefore remains poorly understood. To address this issue, we used selective breeding to create rat sublines with constitutively high (high-5HT) and low (...

Barrier membranes have been extensively used in dentistry to prevent soft tissue down-growth into the bone defects and to promote alveolar ridge augmentation. Previous studies of our group showed that the Poly(vinylidene-trifluoroethylene)/barium titanate composite (PVDF) enhances both the in vitro osteoblastic differentiation and the in vivo bone repair compared with a commercially available polytetrafluoroethylene (PTFE) membrane. As bone formation may be regulated ...

Fibronectin is produced in different isoforms by osteoblasts during differentiation. In contrast to the circulating Isoform, which lacks extra domains, the fibronectin laid down by the osteoblasts in the matrix contains one or both extra-domains called EDA and EDB. We had found that deletion of fibronectin in osteoblasts decreased BMD. This is mediated by diminished osteoblast differentiation and cannot be corrected by the circulating isoform of fibronectin, suggesting a role ...