Unravelling the effect of an osteopetrotic Snx10 mutation on bone, muscle and other tissues

M Stein; M Barnea; S Winograd-Katz; M Shalev; E Arman; O Brenner; F Thalji; M Kanaan; H Elinav; P Stepensky; B Geiger; J Tuckermann; A Elson

doi:10.1055/s-0039-1700643

Osteologie, Inhaltsverzeichnis

Osteologie 2019; 28(04): 293
DOI: 10.1055/s-0039-1700643

Abstracts

Georg Thieme Verlag KG Stuttgart · New York

Unravelling the effect of an osteopetrotic Snx10 mutation on bone, muscle and other tissues

M Stein

¹Department of Comparative Molecular Endocrinology, University of Ulm, Ulm, Germany

,

M Barnea

²Department of Molecular Genetics, The Weizmann Institute of Science, Rehovot 76100, Israel

,

S Winograd-Katz

³Department of Molecular Cell Biology, The Weizmann Institute of Science, Rehovot 76100, Israel

,

M Shalev

²Department of Molecular Genetics, The Weizmann Institute of Science, Rehovot 76100, Israel

,

E Arman

²Department of Molecular Genetics, The Weizmann Institute of Science, Rehovot 76100, Israel

,

O Brenner

⁴Department of Veterinary Resources, The Weizmann Institute of Science, Rehovot 76100, Israel

,

F Thalji

⁵Department of Orthopedics, Istishari Arab Hospital, Ramallah, Palestine

,

M Kanaan

⁶Research Laboratory and Department of Life Sciences, Bethlehem University, Bethlehem, Palestine

,

H Elinav

⁷Department of Clinical Microbiology and Infectious Diseases, Hadassah-Hebrew University Medical Center, Jerusalem, Israel

,

P Stepensky

⁸Department of Bone Marrow Transplantation and Cancer Immunotherapy, Hadassah-Hebrew University Medical Center, Jerusalem, Israel

,

B Geiger

³Department of Molecular Cell Biology, The Weizmann Institute of Science, Rehovot 76100, Israel

,

J Tuckermann

¹Department of Comparative Molecular Endocrinology, University of Ulm, Ulm, Germany

,

A Elson

²Department of Molecular Genetics, The Weizmann Institute of Science, Rehovot 76100, Israel

› Institutsangaben

Abstract

Volltext

Introduction:

Osteopetrosis is a heterogeneous disease of increased bone mass and reduced bone resorption due to osteoclast malfunction. Our trilateral project, together with scientist and physicians from Israel and Palestine, aims to improve patient care and increase understanding of the cellular and molecular details of a severe autosomal recessive form of osteopetrosis caused by a R51Q point mutation in the protein SNX10.

Material and methods:

The experiments are carried out with the help of a murine Snx10 R51Q model as the structure of the protein is highly conserved between human and mouse.

Results:

Long bones in homozygous Snx10 R51Q mice are dense (Bone volume/tissue volume of 5 week old male WT siblings: WT: 5,858 ± 1,359%; Hom: 75,48 ± 9,044%) but brittle (Tissue mineral density of WT: 0,9003 ± 0,03769 CaHA g/cm3; Hom: 0,7690 ± 0,02230 CaHA g/cm3). Mutant mice also show strongly reduced osteoclast numbers (N.Oc./B.Pm (µm): WT 1,358 ± 0,3162; Hom: 0,4076 ± 0,2845) and function in vivo. Ruffled border formation and acid secretion are impaired. Interestingly also osteoblasts numbers are decreased (N.Ob./B.Pm (µm): WT: 20,56 ± 13,00; Hom: 8,281 ± 2,979). Muscles and other tissues, thought smaller in size, appear surprisingly normal.

Discussion:

The analysis of the mouse model confirms the Snx10 R51Q mutation as a cause for osteopetrosis. The bone phenotype can be rescued by autologous WT bone marrow transplantation four days after birth but tooth eruption remains a problem. We are currently investigating the molecular mechanisms of osteoclast and osteoblast impairment as well as chondrocytes in these mice in order to understand the impact of the mutation on chondral versus desmal ossification.

Key words:

Osteopetrosis, µCT, Snx10