gms | German Medical Science

German Congress of Orthopedic and Trauma Surgery (DKOU 2017)

24.10. - 27.10.2017, Berlin

Comparison of osteoblasts from patients with osteoporosis and patients with coxarthrosis combined with osteoporosis

Meeting Abstract

  • presenting/speaker Tanja Niedermair - Klinik und Poliklinik Orthopädie, Experimentelle Orthopädie, ZMB, BioPark1, Universitätsklinikum Regensburg, Regensburg, Germany
  • Benjamin Craiovan - Orthopädische Universitätsklinik Regensburg, Asklepios Klinikum Bad Abbach, Bad Abbach, Germany
  • Joachim Grifka - Orthopädische Universitätsklinik Regensburg, Asklepios Klinikum Bad Abbach, Bad Abbach, Germany
  • Susanne Grässel - Klinik und Poliklinik Orthopädie, Experimentelle Orthopädie, ZMB, BioPark1, Universitätsklinikum Regensburg, Regensburg, Germany

Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2017). Berlin, 24.-27.10.2017. Düsseldorf: German Medical Science GMS Publishing House; 2017. DocGR14-710

doi: 10.3205/17dkou498, urn:nbn:de:0183-17dkou4981

Published: October 23, 2017

© 2017 Niedermair et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 License. See license information at http://creativecommons.org/licenses/by/4.0/.


Outline

Text

Objectives: Bone, bone marrow and periosteum are innervated by sensory and sympathetic nerve fibers. Disorders of peripheral nerves can have substantial influence on bone health and regeneration and dramatic alterations in nerve fiber density and distribution are reported in musculoskeletal pathophysiology. Patients with osteoporosis have decreased bone strength and bone quality, and are more prone to fractures. There is numerous evidence that the sensory and sympathetic nervous system modulate bone metabolism via their neurotransmitters and may even promote an osteoporotic bone phenotype by modulating osteoblast metabolism. This study investigates viability, activity of osteoblasts and their gene expression profile of neurotransmitter receptors neurokinin 1 (NK1R), calcitonin receptor-like receptor (CRLR) and adrenergic receptor β2 (ARβ2) in osteoblasts from patients with osteoporosis alone or coxarthrosis combined with osteoporosis.

Methods: Osteoblast-like cells, migrated out of bone chips obtained from patients with osteoporosis (OP) or coxarthrosis combined with osteoporosis (Cox/OP) after hip replacement surgery, were cultured in growth medium until confluency. Cells were then re-seeded and kept in osteogenic medium for 14, 21, 28 and 35 days. Viability was measured using WST-1 reagent. ALP activity and alizarin red staining were analyzed to determine bone formation activity. Gene expression of NK1R, CRLR and ARβ2 was analyzed by quantitative RT-PCR.

Results and Conclusion: Osteoblasts from patients with OP are more viable compared to osteoblasts from patients with Cox/OP throughout all osteogenic differentiation time points. At early differentiation time points (days 14/ 21) ALP activity was lower in osteoblasts from patients with OP compared to Cox/OP osteoblasts. At late differentiation time points (days 28/ 35) osteoblasts from patients with OP produced less bone matrix compared to Cox/OP osteoblasts. With respect to neurotransmitter receptor expression, ARβ2 gene expression was higher in osteoblasts from patients with OP at day 14 of osteogenic differentiation compared to Cox/OP osteoblasts. Gene expression of ARβ2 declined during osteogenic differentiation in both, osteoblasts from patients with OP and Cox/OP. At day 28 of osteogenic differentiation, CRLR gene expression was reduced in osteoblasts from patients with OP but increased again at day 35. There was no difference in NK1R gene expression between osteoblasts from OP and Cox/OP during culture time.

We assume that the course of disease in patients with OP or Cox/OP differently affects metabolic processes in osteoblasts resulting in inferior bone matrix quality as we found differences in cell viability, ALP activity and bone matrix formation during osteogenic differentiation. Additionally, differences in expression profiles of ARβ2 and CRLR between osteoblasts from OP and Cox/OP during osteogenic differentiation could possibly contribute to differences in osteoblast metabolism.