Bone Abstracts

Introduction: Mesenchymal stem cells (MSCs) counteract the decline of physiologic functions but their regenerative power decreases with age. In particular osteogenic differentiation capacity of MSCs has been shown to decrease with age thereby contributing to slowed down bone formation and osteoporosis. While much is known about cellular aging of MSCs, little is known about extrinsic factors influencing their functionality. Here we set out to identify circulating factors of the...

Aging is a complex process that results in the decline of physiologic functions due to accumulation of damage in cells and tissues. Mesenchymal stem cells (MSCs) counteract this decline but their regeneration capacity decreases with age. In particular osteogenic differentiation potential of MSCs has been shown to decrease with age thereby contributing to slowed down bone formation and osteoporosis. While much is known about cellular aging of MSCs, little is known about factors...

Background: Autocrine and paracrine Wnt signaling operates in stem cell populations and regulates mesenchymal lineage specification. In Wnt producing cells, Wntless (GPR177) supports the transport of Wnt from the trans-Golgi network (TGN) to the cell surface in vesicles, from which Wnt is then released. The retromer complex (VPS35) interacts with Wntless and retrieves Wntless from endosomes back to TGN, thereby maintaining the normal levels of Wntless protein. V-ATPases-driven...

Little is known about the molecular mechanisms underlying the interaction between Sclerostin (SOST) and estrogen, showing an inverse relation in clinical data. Therefore, we investigated mechanisms by which estrogen modulates Sost expression at human osteoblastic cell level in association with BMP-2 signaling, which is a potential route of SOST induction. BMP-2 significantly induced SOST expression, which is suppressed by 17β-estradiol (E2) in human mesenchymal s...

Background: Hypoxia induces mesenchymal stem cells (MSCs) proliferation but results in a population with impaired osteogenic differentiation potential. Bone healing of tibial lengthening is enhanced by hyperbaric oxygen therapy. However, little is known about the effects of HBO on the Wnt signaling pathway in MSCs.Materials and methods: MSCs were cultured in complete medium and the osteogenic groups were cultured in osteogenic induction medium. Control c...

Background: The activation of Wnt/β-catenin signaling promotes cellular senescence and induces matrix metalloproteinases (MMPs) expression in intervertebral disc (IVD). However, little is known about the effects of hyperbaric oxygen (HBO) on the Wnt/β-catenin signaling and MMPs expression in degenerated human IVDs.Materials and methods: Nucleus pulposus cells (NPCs) were separated from the degenerated disc nucleus tissue by performing sequentia...

Background: Expression of toll-like receptor (TLR) 2 and 4 was up-regulated in lesional areas of OA cartilage. Hyperbaric oxygen (HBO) reduces the TLR signalling pathway in multiple organ failures. However, little is known about the effects of HBO on the catabolic pathway mediated by TLRs in human osteoarthritic (OA) chondrocytes.Materials and methods: OA chondrocytes were separated from the knees of OA patients by performing sequential enzymatic digesti...

Introduction: The fat-soluble and vitamin K2 homologe Menaquinone-7 (MK-7) is needed for post-translational modification of proteins essential in blood coagulation, and in metabolic pathways in various tissues like bone. Recent studies found an association between long-term anticoagulant treatment (OAC) and reduced bone quality due to reduction of active osteocalcin. OAC is often linked to an undesired soft-tissue calcification in both children and adults and may lead to incre...

The objective of this investigation was to compare bone mineral density (BMD) attained from dual-energy X-ray DXA with speed of sound (SOS) data attained from a Beam-Med Omnisense multisite quantitative ultrasound (mQUS) in a large sample of randomly-selected community-based individuals from the Canadian Multicentre Osteoporosis Study (CaMOS). A total of 1177 men and 2949 women were assessed with mQUS at the distal radius, tibia, and phalanx sites as part of the Canadian Multi...

Background and aims: Low bone formation is the main pathogenic mechanism of osteoporosis in primary biliary cirrhosis (PBC). Sclerostin, an inhibitor of the Wnt pathway, is involved in the regulation of osteoblastogenesis and little is known about its role in the development of bone disease in PBC. Thus, we evaluated the circulating levels of sclerostin and its relationship to bone mass, the parameters of mineral metabolism and liver disease severity.Met...