LncRNA KCNQ1OT1 delayed fracture healing through the Wnt/β-catenin pathway

The aim of this study was to explore the effect of long non-coding ribonucleic acid (lncRNA) KCNQ1 overlapping transcript 1 (KCNQ1OT1) on fracture healing and its possible mechanism.

Abnormal lncRNAs were compared between patients with delayed fracture healing and those with normal fracture healing using gene expression profiling method. LncRNA expression in patients was verified by quantitative Reverse Transcription-Polymerase Chain Reaction (qRT-PCR). Subsequently, the model of tibial fracture was successfully established in rabbits. The effect of lncRNA KCNQ1OT1 expression on tibial fracture healing in rabbits was explored. Meanwhile, the effects of lncRNA KCNQ1OT1 on cell proliferation and apoptosis were investigated by knockdown and overexpression experiments with HC-a as a cell model. Furthermore, Western blotting was used to explore the expressions of proteins in signaling pathway affected by lncRNA KCNQ1OT1.

Gene expression profiling and qRT-PCR revealed that lncRNA KCNQ1OT1 was significantly down-regulated in bone tissues of patients with delayed fracture healing. Compared with the control group, knocking down lncRNA KCNQ1OT1 remarkably reduced the serum levels of alkaline phosphatase (ALP) and osteoprotegerin (OPG) in rabbits, and markedly decreased bone trabecular growth index (p<0.05). In HC-a cells, overexpression of lncRNA KCNQ1OT1 activated the Wnt/β-catenin signaling pathway, which could be suppressed by knocking down lncRNA KCNQ1OT1. Cell Counting Kit-8 (CCK-8) assay and 5(6)-carboxyfluorescein diacetate, succinimidyl ester (CFSE) results manifested that lncRNA KCNQ1OT1 remarkably promoted the proliferation and inhibited apoptosis of HC-a cells by activating the Wnt/β-catenin signaling pathway.

LncRNA KCNQ1OT1 plays a vital role in delayed fracture healing. Moreover, it can induce cell proliferation and inhibit cell apoptosis by activating the Wnt/β-catenin signaling pathway. Therefore, KCNQ1OT1 may be used as a biomarker to predict the occurrence of delayed fracture healing.