Research Paper Volume 11, Issue 24 pp 12793—12809
Loss of Klotho contributes to cartilage damage by derepression of canonical Wnt/β-catenin signaling in osteoarthritis mice
- 1 Department of Orthopedics, Nanjing First Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
- 2 Department of Orthopedics, The Affiliated Jiangyin Hospital of Medical School of Southeast University, Jiangyin, China
- 3 Cartilage Regeneration Center, Nanjing First Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
- 4 Digital Medicine Institute, Nanjing Medical University, Nanjing, Jiangsu, China
Received: March 29, 2019 Accepted: December 5, 2019 Published: December 30, 2019
https://doi.org/10.18632/aging.102603How to Cite
Copyright © 2019 Gu et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY 3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Abstract
Caducity is known to be an independent risk factor in osteoarthritis (OA), yet the molecular basis behind caducity and OA remains unclear. Klotho, an anti-caducity protein, is an endogenous antagonist of the transduction of Wnt/β-catenin signal which can stimulate the articular cartilage degradation, indicating that deficiency in Klotho may increase Wnt/β-catenin activity and consequently accelerate the development of OA. We found that expression of Klotho was markedly higher in normal mouse cartilage than in the OA model, and in this model the activity of Wnt/β-catenin and its target gene was up-regulated. Decrease in Klotho expression was closely associated with the increase of β-catenin in OA, indicating that there was a negative correlation between Klotho and Wnt signal transduction. In the vitro and in vivo experiments, Klotho was found to bind to multiple Wnt, including Wnt1, Wnt4 and Wnt7a. It was additionally found that cyclic tenisle strain (CTS) inhibited the expression of Klotho and activated β-catenin. On the contrary, over-expression of Klotho would reduce the degradation of articular cartilage induced by CTS. These results suggest that Klotho is an antagonist of endogenous Wnt/β-catenin activity. In OA cartilage, decrease in expression of Klotho can activate Wnt/β-catenin signal transduction and consequently induce cartilage injury.