Abstract
BackgroundOsteoarthritis (OA) is a chronic degenerative disease of the joints characterized by articular cartilage damage, subchondral bone remodeling, osteophyte formation, and inflammatory changes. This work aims to investigate the protective role of long non-coding RNA (lncRNA) maternally expressed 3 (MEG3) against the apoptosis of chondrocytes.MethodsChondrocyte cell lines, CHON-001, and ATDC5 were treated with different doses of interleukin-1β (IL-1β) to mimic the inflammatory response during OA pathogenesis. Quantitative real-time polymerase chain reaction was performed to measure MEG3, miR-9-5p, and Krüppel-like factor 4 (KLF4) mRNA expression levels. MEG3 and KLF4 overexpression plasmids, MEG3 shRNA, miR-9-5p mimics, and miR-9-5p inhibitors were transfected into the cells. Cell counting kit-8, wound healing assay, and flow cytometry were conducted to determine cell viability, migration, and apoptotic rate. Dual-luciferase reporter assay was adopted to verify the targeting relationships among MEG3, miR-9-5p, and KLF4. Western blot was used to detect KLF4 protein expression. Enzyme-linked immunosorbent assay was employed to measure the levels of inflammatory factors.ResultsMEG3 expression in chondrocytes was down-regulated by the stimulation of IL-1β, and MEG3 negatively regulated miR-9-5p expression but positively regulated KLF4 expression. MEG3 overexpression strengthened the viability and migration of CHON-001 and ATDC5 cells but restrained the apoptosis and inflammatory response, while MEG3 knockdown had opposite effects. miR-9-5p inhibition or KLF4 overexpression could counteract the effects of MEG3 knockdown on chondrocytes. Besides that, MEG3 was proved to be a molecular sponge for miR-9-5p, and KLF4 was verified as the target of miR-9-5p.ConclusionMEG3 can promote chondrocyte proliferation and migration and inhibit apoptosis and inflammation by sponging miR-9-5p to induce KLF4 expression, which provides a promising therapy target for OA treatment.
Highlights
Osteoarthritis (OA) is the most common chronic joint disease featured with articular cartilage degeneration, inflammatory reaction, and osteophyte formation (Loeser et al, 2012)
We demonstrated that MEG3 and Krüppel-like factor 4 (KLF4) expression levels were remarkably down-regulated in chondrocytes stimulated with IL-1β, while miR-9-5p expression level was increased
The Quantitative realtime polymerase chain reaction (qRT-PCR) implied that MEG3 expression was significantly down-regulated in CHON-001 and ATDC5 cell lines treated with IL-1β (Figure 2A)
Summary
Osteoarthritis (OA) is the most common chronic joint disease featured with articular cartilage degeneration, inflammatory reaction, and osteophyte formation (Loeser et al, 2012). Interleukin-1β (IL-1β) is an important inflammatory factor and can play a role in the initiation and early progression of OA (Daheshia and Yao, 2008). Many lncRNAs are implicated in regulating cartilage function and OA progression, such as SNHG1, OIP5-AS1, and maternally expressed 3 (MEG3) (Lei et al, 2019; Wang A. et al, 2019; Zhi et al, 2020). Osteoarthritis (OA) is a chronic degenerative disease of the joints characterized by articular cartilage damage, subchondral bone remodeling, osteophyte formation, and inflammatory changes. This work aims to investigate the protective role of long non-coding RNA (lncRNA) maternally expressed 3 (MEG3) against the apoptosis of chondrocytes
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
