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Bone & Joint Research
Vol. 7, Issue 2 | Pages 139 - 147
1 Feb 2018
Takahara S Lee SY Iwakura T Oe K Fukui T Okumachi E Waki T Arakura M Sakai Y Nishida K Kuroda R Niikura T

Objectives

Diabetes mellitus (DM) is known to impair fracture healing. Increasing evidence suggests that some microRNA (miRNA) is involved in the pathophysiology of diabetes and its complications. We hypothesized that the functions of miRNA and changes to their patterns of expression may be implicated in the pathogenesis of impaired fracture healing in DM.

Methods

Closed transverse fractures were created in the femurs of 116 rats, with half assigned to the DM group and half assigned to the control group. Rats with DM were induced by a single intraperitoneal injection of streptozotocin. At post-fracture days five, seven, 11, 14, 21, and 28, miRNA was extracted from the newly generated tissue at the fracture site. Microarray analysis was performed with miRNA samples from each group on post-fracture days five and 11. For further analysis, real-time polymerase chain reaction (PCR) analysis was performed at each timepoint.


The Bone & Joint Journal
Vol. 97-B, Issue 8 | Pages 1144 - 1151
1 Aug 2015
Waki T Lee SY Niikura T Iwakura T Dogaki Y Okumachi E Kuroda R Kurosaka M

MicroRNAs (miRNAs ) are small non-coding RNAs that regulate gene expression. We hypothesised that the functions of certain miRNAs and changes to their patterns of expression may be crucial in the pathogenesis of nonunion. Healing fractures and atrophic nonunions produced by periosteal cauterisation were created in the femora of 94 rats, with 1:1 group allocation. At post-fracture days three, seven, ten, 14, 21 and 28, miRNAs were extracted from the newly generated tissue at the fracture site. Microarray and real-time polymerase chain reaction (PCR) analyses of day 14 samples revealed that five miRNAs, miR-31a-3p, miR-31a-5p, miR-146a-5p, miR-146b-5p and miR-223-3p, were highly upregulated in nonunion. Real-time PCR analysis further revealed that, in nonunion, the expression levels of all five of these miRNAs peaked on day 14 and declined thereafter.

Our results suggest that miR-31a-3p, miR-31a-5p, miR-146a-5p, miR-146b-5p and miR-223-3p may play an important role in the development of nonunion. These findings add to the understanding of the molecular mechanism for nonunion formation and may lead to the development of novel therapeutic strategies for its treatment.

Cite this article: Bone Joint J 2015; 97-B:1144–51.


Orthopaedic Proceedings
Vol. 96-B, Issue SUPP_11 | Pages 350 - 350
1 Jul 2014
Lee S Okumachi E Dogaki Y Niikura T Iwakura T Waki T Nishida K Kurosaka M
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Summary Statement

Low-intensity pulsed ultrasound (LIPUS) enhanced osteogenic differentiation of osteoprogenitor cells derived from mouse induced pluripotent cells (iPSCs) without embryoid body formation. Our findings provide insights on the development of LIPUS as an effective technology for bone regeneration strategies using iPSCs.

Introduction

iPSCs represent a promising cell source for regenerative medicine such as bone regeneration because of their unlimited self-renewal property and ability of differentiation into all somatic cell types. Recently, we developed an efficient protocol for generating a highly homogeneous population of osteoprogenitor cells from embryonic stem cells by using a direct-plating method without EB formation step. It is well-recognised that LIPUS accelerates the fracture healing. There have been several reports showing that LIPUS stimulates the osteogenic differentiation of mesenchymal stem cells (MSCs) in vitro. To date, effect of LIPUS on iPSCs remains unknown. In this study, we investigated in vitro effect of LIPUS on osteogenic differentiation of osteoprogenitor cells derived from mouse iPS cells via a direct-plating method.