Research Paper Volume 12, Issue 20 pp 20163—20183
Down-regulated ciRS-7/up-regulated miR-7 axis aggravated cartilage degradation and autophagy defection by PI3K/AKT/mTOR activation mediated by IL-17A in osteoarthritis
- 1 Department of Orthopedics, The Affiliated Changzhou No.2 People’s Hospital of Nanjing Medical University, Changzhou 213000, China
- 2 Department of Orthopedic Surgery, The Second Affiliated Hospital of Jiaxing University, Jiaxing 314000, China
- 3 Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215000, China
- 4 Department of Orthopedic Surgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310000, China
Received: February 15, 2020 Accepted: June 25, 2020 Published: October 25, 2020
https://doi.org/10.18632/aging.103731How to Cite
Copyright: © 2020 Zhou 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
Osteoarthritis (OA) is one of the most painful and widespread chronic degenerative joint diseases and is characterized by destructed articular cartilage and inflamed joints. Previously, our findings indicated that circular RNA ciRS-7 (ciRS-7)/microRNA 7 (miR-7) axis is abnormally expressed in OA, and regulates proliferation, inflammatory responses, and apoptosis of interleukin-1β (IL-1β)-stimulated chondrocytes. However, its underlying role in OA remains unknown.
In this study, we first validated cartilage degradation and defection of autophagy in samples of OA patients. IL-1β initially stimulated autophagy of chondrocytes, and ultimately significantly suppressed autophagy. Upregulated ciRS-7/down-regulated miR-7 aggravated IL-1β-induced cartilage degradation, and restrained autophagy in vitro. Gene sequencing and bioinformatics analysis performed on a control group, IL-1β group, and IL-1β+miR-7-mimics group demonstrated that seven of the most significant mRNA candidates were enriched in the interleukin-17 (IL-17) signaling pathway. Increased IL-17A levels were also observed by qRT-PCR and ELISA. In addition, it was revealed that the ciRS-7/miR-7 axis ameliorated cartilage degradation and defection of autophagy by PI3K/AKT/mTOR activation in IL-1β-induced chondrocytes. Furthermore, an OA model was established in rats with medial meniscus destabilization. miR-7-siRNA-expressing lentiviruses alleviated surgical resection-induced cartilage destruction of OA mice, whereas miR-7 mimics worsened the effects. Thus, these findings revealed that the mechanism of the ciRS-7/miR-7 axis involved regulating OA progression and provided valuable directions for OA treatment.