Searchable abstracts of presentations at key conferences on calcified tissues

ba0001pp184 | Cell biology: osteoblasts and bone formation | ECTS2013

Activation of β-catenin signalling enhances the osteogenic gene response to mechanical loading in mesenchymal stem cells

Nemitz Claudia , Jakob Franz , Ignatius Anita , Liedert Astrid

Introduction: Wnt/β-catenin signalling and mechanical loading are able to inhibit adipogenesis and to stimulate osteoblastogenesis of mesenchymal stem cells1,2. The involvement of β-catenin signalling in mechanically induced bone formation has already been shown in vivo using a tibia loading model3. The aim of this study was to investigate the influence of the activation of β-catenin on the osteogenic and adip...

ba0003pp23 | Bone biomechanics and quality | ECTS2014

Influence of estrogen receptor and β-catenin signalling activation on mechanically induced bone formation in ovariectomized mice

Nemitz Claudia , Jakob Franz , Ignatius Anita , Liedert Astrid

Dysfunctions of Wnt/β-catenin and estrogen receptor signalling resulted in impaired mechanotransduction and bone loss as in osteoporosis. Previous studies demonstrated the interaction of these pathways in mechanotransduction in vitro and in vivo. In this study, the influence of the activation of estrogen receptor and β-catenin signalling on mechanically induced bone formation was investigated in ovariectomized mice. 12-week-old mice were ovariectomi...

ba0001oc2.3 | Bone quality and fracture repair - animal models | ECTS2013

Low-magnitude high-frequency vibration improves fracture healing in aged, ovariectomized mice

Wehrle Esther , Bindl Ronny , Wehner Tim , Heilmann Aline , Fischer Lena , Noland Jarrod , Amling Michael , Ignatius Anita

Introduction: Fracture healing is impaired in aged and osteoporotic patients. Because bone formation is tightly regulated by the mechanical conditions in the fracture gap and because suitable mechanical stimuli improve fracture healing (Claes et al. 1998), we investigated whether low-magnitude high-frequency vibration (LMHFV; Rubin et al. 2004) is able to improve delayed fracture healing induced by age and ovariectomy in mice.Sudy desig...

ba0003pp46 | Bone development/growth and fracture repair | ECTS2014

Midkine deficiency significantly delayed chondrogenesis during fracture healing in mice

Haffner-Luntzer Melanie , Heilmann Aline , Rapp Anna , Schinke Thorsten , Amling Michael , Ignatius Anita , Liedert Astrid

One growth factor that potentially plays a role in fracture healing is midkine (Mdk). Mdk is expressed in chondrocytes during bone repair (Ohta et al. 1999) and has been shown to influence bone mass and mechanotransduction (Neunaber et al. 2010, Liedert et al. 2011). The aim of the present study was to evaluate the effects of Mdk-deficiency on bone repair in a standardized mouse femur osteotomy model.Mdk-deficient and wildtype ...

ba0005p45 | Bone development/growth and fracture repair | ECTS2016

Mast cells regulate inflammation and bone regeneration in fracture healing

Kroner Jochen , Kovtun Anna , Messmann Joanna , Strauss Gudrun , Seitz Sebastian , Schinke Thorsten , Dudeck Anne , Ignatius Anita

Mast cells (MCs) are pro-inflammatory sensor and effector cells of the immune system. MCs seem to play a role in bone metabolism, because patients with systemic mastocytosis develop osteoporosis. MCs are present in the fracture callus during bone healing, however, their function has not yet been investigated. Here, we examined the role of MCs in the inflammatory and repair phase during fracture healing.Male 12-week old MC deficient mice (Mcpt5-Cre R-DTA)...

ba0005p54 | Bone development/growth and fracture repair | ECTS2016

Role of interleukin-6 in the early and late fracture healing phase

Prystaz Katja , Kovtun Anna , Kaiser Kathrin , Heidler Verena , Kroner Jochen , Haffner-Luntzer Melanie , Ignatius Anita

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...

ba0005p55 | Bone development/growth and fracture repair | ECTS2016

Calcium and vitamin-D supplementation post-trauma improves bone healing and decreases posttraumatic bone resorption in an osteoporotic mouse model

Heidler Verena , Haffner-Luntzer Melanie , Prystaz Katja , Kroner Jochen , Schinke Thorsten , Amling Michael , Ignatius Anita

Chronic calcium- and vitamin-D-deficiencies are crucial risk factors for osteoporosis. However, their significance for fracture healing is still poorly investigated, despite the clinical evidence that osteoporotic bone healing is disturbed. This study addressed the important question, whether chronic deprivation of calcium and vitamin D compromises bone repair and if this could be rescued by a supplementation post-trauma. Because clinical hints suggest that a fracture induces ...

ba0005p59 | Bone development/growth and fracture repair | ECTS2016

Midkine is involved in the pathogenesis of delayed osteoporotic fracture healing after ovariectomy in mice

Haffner-Luntzer Melanie , Kemmler Julia , Heidler Verena , Prystaz Katja , Schinke Thorsten , Amling Michael , Ignatius Anita , Liedert Astrid

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...

ba0001pp74 | Bone development/growth and fracture repair | ECTS2013

Metaphyseal fracture healing in a sheep model of low turnover osteoporosis induced by hypothalamic–pituitary disconnection

Bindl Ronny , Oheim Ralf , Pogoda Pia , Beil Frank Timo , Gruchenberg Katharina , Reitmaier Sandra , Wehner Tim , Calcia Enrico , Radermacher Peter , Claes Lutz , Amling Michael , Ignatius Anita

We recently established a large animal model of osteoporosis in sheep using hypothalamic–pituitary disconnection (HPD). As central regulation is important for bone metabolism, HPD-sheep developed severe osteoporosis because of low bone turnover. In this study we investigated metaphyseal fracture healing in HPD-sheep. To elucidate potential pathomechanisms, we included a treatment group receiving thyroxine (T4) and 17β-estradiol. Because clinically osteopor...