# Circ_0088200 acts as a sponge for miR-127-5p to promote the migration and invasion of rheumatoid arthritis fibroblast-like synoviocytes

## TL;DR

This study finds that a circular RNA called Circ_0088200 promotes the spread of rheumatoid arthritis cells by acting as a sponge for miR-127-5p, offering a new potential treatment target.

## Contribution

The study identifies Circ_0088200 as a novel circRNA that promotes RA progression by sponging miR-127-5p and regulating MMP1.

## Key findings

- Circ_0088200 is highly expressed in rheumatoid arthritis fibroblast-like synoviocytes and correlates with disease severity.
- Circ_0088200 promotes cell migration and invasion by sponging miR-127-5p and upregulating MMP1.
- Injecting Circ_0088200 in mice worsens arthritis severity, confirming its role in vivo.

## Abstract

Circular RNAs (circRNAs) play a crucial role in the development of various diseases. However, few studies have investigated the role of circRNAs in rheumatoid arthritis (RA). Herein, we aimed to identified the novel circRNAs involved in the migration and invasion of RA fibroblast-like synoviocytes (RA-FLS).

The RA-FLS were isolated from the synovial membrane of patients with RA. The CircRNA profile was screened by CircRNA microarray analysis. Circ_0088200 and miR-127–5p expression levels were detected using quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR). The protein level of matrix metalloproteinase 1 (MMP1) was evaluated by western blotting. Wound healing and Transwell assays were performed to analyze the migration and invasion of RA-FLS. RNA immunoprecipitation (RIP) and dual-luciferase reporter assays were used to validate the interaction between Circ_0088200 and miR-127–5p. Collagen-induced arthritis (CIA) mouse models were established to evaluate the role of Circ_0088200 in the development of arthritis in vivo.

Circ_0088200 was highly expressed in RA-FLS compared with osteoarthritis fibroblast-like synoviocytes (OAFLS) and correlated positively with the disease activity score in 28 joints. Inhibition of Circ_0088200 suppressed the migration and invasion of RA-FLS. Conversely, overexpression of Circ_0088200 significant promoted the migration and invasion of RA-FLS. Mechanistically, Circ_0088200 functions as a sponge for miR-127–5p and relieve its repressive effect on MMP1, thereby promoting the migration and invasion of RA-FLS. Importantly, intra-articular injection of Adenoassociated virus expressing Circ_0088200 significantly increased the severity of arthritis in mice with CIA.

Circ_0088200 promotes the migration and invasion of RA-FLS by sponging miR-127–5p. Thus Circ_0088200 is a potential therapeutic target for RA.