Bone Abstracts

Objectives: Osteogenesis Imperfecta (OI) type XIV is a recessive OI form characterized by bone fragility, multiple fractures and growth retardation. It is caused by mutation in TMEM38B gene encoding the endoplasmic reticulum (ER) channel TRIC-B. This channel allows the transport of K+ across the ER membrane modulating Ca2+ flux. Defective ER Ca2+ impaires collagen type I synthesis, likely affecting the activity of ER enzymes involved in its post translational modification. To ...

Background: Proline and hydroxyproline account for ~25% of aminoacids in collagen., Prolidase (peptidase D (EC 3.4.14.9)), cleaves iminodipeptides with a C-terminal proline or hydroxyproline, playing a major role in collagen catabolism. Mice with prolidase deficiency (PD) present with varied phenotypes including reduced size compared to wild-type littermates. We measured structural and mechanical properties of bones in PD mice.Methods: Whole femurs from ...

Bone tissue homeostasis requires the coordinated activity of osteoblasts, the bone forming cells, of osteoclasts, the bone resorbing cells, and of osteocytes, generally referred as the bone mechano-sensors. In this contest, osteoblasts are the mesenchymal cells secreting the extracellular matrix components on which hydroxyapatite crystals are then deposited. The most abundant protein of this organic matrix is type I collagen, a heterotrimeric secretory protein, synthesized as ...

Bone is a complex tissue constituted by a mineral phase, hydroxyapatite, and an organic phase, mainly represented by collagen type I. Specialized cells are responsible for bone formation and remodeling. Osteoblasts represent the bone forming cells, osteocyte are the orchestrator of bone remodeling through regulation of the other bone cells activity, by functioning as endocrine cells and by acting as mechanosensor, and osteoclasts, the bone resorbing cells. Mesenchymal osteopro...

Objectives: Osteogenesis imperfecta (OI) is a heritable disorder characterized by bone deformity and skeletal fragility. Cartilage associated protein (CRTAP), proline 3-Hydroxylase 1 (P3H1) and Cyclophylin B (PPIB) are components of the endoplasmic reticulum (ER)-resident complex involved in the 3-hydroxylation of specific proline residues in collagen type I α chains. Mutations in these proteins are responsible for recessive OI type VII, VIII and IX, respectively. Murine ...