Bone Abstracts

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The essential micronutrient Selenium (Se) plays an important role for bone formation and homeostasis. This notion is mainly derived from animal experimental studies showing impaired bone development and reduced measures of bone quality in animals on diets with low Se supply. Selenoprotein P (SePP) functions as the central Se storage and transport protein. SePP-knockout mice have a growth deficit. SePP is taken up by a receptor-mediated mechanism. We hypothesize that impaired S...

Glycosphingolipids (GSL) are essential structural components of mammalian cell membranes and lipid rafts that exert pleiotropic effects on cell survival, proliferation, and differentiation. Cancer associated GSL have been shown to promote tumor growth, angiogenesis, and metastasis; however their role in osteoclast (OC) activation and the development of osteolytic bone diseases such as multiple myeloma are not known. We investigated the hypothesis that GSL contribute to OC acti...

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 ...

Glucocorticoid (GC)-induced osteoporosis (GIO) occurs in patients undergoing therapeutic intervention for inflammatory disorders such as rheumatoid arthritis and lupus. The effect of long-term GC administration on bone turnover was investigated in two frequently used mouse strains; C57BL/6 and CD1 in order to assess the influence of genetic background.GIO was induced in 12 weeks old female C57BL/6 and CD1 mice by s.c. insertion of long-term (60 days) rel...

Tumors contain a small population of cancer stem cells (CSC) proposed to be responsible for tumor maintenance and relapse. Aldehyde dehydrogenase 1 (ALDH1) activity has been used as a functional stem cell marker to isolate CSCs in different cancer types. This study used the Aldefluor assay and fluorescence-activated cell sorting (FACS) analysis to isolate ALDH1high cells from five human sarcoma cell lines and one primary chordoma cell line. ALDH1high cell...

Chordomas are rare, low to intermediate grade malignant bone tumors of the axial skeleton. Current treatment options are limited to surgical procedures as chordomas are largely resistant to conventional radiation and chemotherapy. Cell lines are valuable tools to explore molecular mechanisms involved in tumorigenesis and they have a fundamental impact on the development of new anticancer agents. We established a novel chordoma cell-line, MUG-Chor1, from a recurrent morphologic...

Osteoclast (OC)-mediated bone destruction is a key feature of rheumatoid arthritis (RA). In RA synovial tissue a reduced density of catecholaminergic nerve fibres has been observed. Studies on sweat gland innervation proved that catecholaminergic fibres have the ability to undergo a phenotypic transition to cholinergic nerves. The sympathetic neurotransmitters norepinephrine (NE), acetylcholine (ACh), and vasoactive intestinal peptide (VIP) affect osteoclastogenesis oppositely...

Osteoclast resorption depends on their ability to reorganise their actin cytoskeleton and form the sealing zone. In order to resorb bone, osteoclasts become polarised by condensing their podosomes into a highly dynamic podosomal belt. The podosome turnover is regulated by several factors such as non-receptor tyrosine kinases, small GTPases and actin-binding proteins. The innate immune system responds to viral pathogens. Cytoplasmic double-stranded DNA activates the immune syst...

Osteocytes make up >90% of bone cells, are embedded in mineralised matrix where they form a communication network. Osteocytes differentiate from osteoblasts, and are mechano-sensitive. They are very difficult to isolate with a dependence on cell lines for in vitro studies of osteocyte biology. Therefore new methods to study these cells are essential. Recent publications indicate that osteoblasts maintained in in vitro 3D collagen gels may differentiate to...