Bone Abstracts

Introduction: One third of patients in the long-term heparin therapy show reduction in bone density. We have shown that heparin binds to bone morphogenetic protein 6 (BMP6) and inhibits its osteogenic activity in vitro. Here we explored whether heparin effects BMP6 mediated bone efficacy in vivo.Methods: We have used a mouse model of postmenopausal osteoporosis and tested the effect of heparin on BMP6 therapy and its osteogenic activity...

Prolyl hydroxylase 2 (PHD2) regulates hypoxia-inducible factor α (HIFα) transcription factors and thus, erythropoietin (EPO) production. Under normoxic conditions, HIFα is constantly inactivated through hydroxylation by PHD2. Due to the embryonic lethality of PHD2 knock-out mice, its precise role in erythropoiesis and tissue homeostasis has long remained unknown. Recently, we generated a conditional knock-out (cKO) mouse lacking PHD2 in EPO-producing cells. Thes...

Type 2 diabetes mellitus impairs bone quality and increases fracture risk. We showed that diabetic ZDF rats have low bone mass due to impaired osteoblastogenesis, which can be partially reversed with an intermittent parathyroid hormone 1–84 (PTH) therapy. It remains unclear, why PTH treatment does not fully restore osteoblast (OB) function in diabetic conditions. Here, we tested if high glucose (HG) conditions lead to a partial PTH resistance in osteoblasts. Pre-osteoblas...

Iron overload due to hemochromatosis or chronic blood transfusions has been implicated in the development of osteoporosis. However, the impact of iron overload or iron deficiency on stromal cell functions and the underlying mechanisms are poorly defined. Since the Wnt signaling pathway is a critical regulator of bone remodelling, we aimed to analyse the effects of iron overload and iron deficiency on osteoblast function and further define the role of Wnt signaling in these pro...

Hyperthyroidism in mice is associated with a low bone mass, an increased bone turnover and high serum levels of sclerostin, a potent Wnt inhibitor. Here, we explored the effects of either reducing bone turnover with bisphosphonates or increasing bone formation with neutralizing sclerostin antibodies (Scl-Ab) on bone mass and estimated strength in hyperthyroid mice.Twelve-week-old C57BL/6 male mice were rendered hyperthyroid by adding L-thy...

Background: Neonatal hypocalcemia is defined as S-Ca <2 mmol/l in fullterm newborns and <1.75 mmol/l in preterm newborns. Neonatal hypocalcemia is either early onset (<3 days of age) or late onset (>3 days of age). Newborns with hypocalcemia are often asymptomatic, but mays present with hypotonia, apnea, poor feeding, jitteriness, seizures, cardiac failure. Signs of hypocalcemia rarely occur unless S-Ca drops below 1.75 mmol/l.Case presen...

Background: Spondylometaphyseal dysplasias (SMDs) comprise a diverse group of skeletal dysplasias and often manifest as short stature, growth-plate irregularities, and vertebral anomalies. One such condition is SMD with ‘corner fractures’ (OMIM #184255). These individuals generally show development of coxa vara, scoliosis and triangular ossification centers at the edges of metaphyses that simulate fractures.Presenting problem: To date only 16 p...

Objectives: To evaluate the frequency of low serum alkaline phosphatase (ALP) activities in patients referred to a tertiary children’s hospital. Another item was to explore potentially missed diagnoses and to evaluate the role of laboratory screening for hypophosphatasia.Study design: A retrospective evaluation over an 6-year period (between December 2010 and December 2016) carried out to identify children and adolescents, referred to Anna Meyer Chi...

see PP17....

Objective: Wnt/β-catenin pathway is a main regulator of bone remodeling, but might be inhibited in cartilage in osteoarthritis (OA). We here investigated the effect of mechanical loading in Wnt activation and the expression of Wnt antagonists in the joint tissues.Methods: Topgal mice were used. Mice underwent partial meniscectomy (Mnx) and sacrificed at 4, 6, and 9 weeks. Dissected knees were scanned by microCT and then prepared for cryosectioning t...