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. 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.Objectives
Methods
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:
