CircRNAs in osteoarthritis: research status and prospect

Abstract

Osteoarthritis (OA) is the most common joint disease globally, and its progression is irreversible. The mechanism of osteoarthritis is not fully understood. Research on the molecular biological mechanism of OA is deepening, among which epigenetics, especially noncoding RNA, is an emerging hotspot. CircRNA is a unique circular noncoding RNA not degraded by RNase R, so it is a possible clinical target and biomarker. Many studies have found that circRNAs play an essential role in the progression of OA, including extracellular matrix metabolism, autophagy, apoptosis, the proliferation of chondrocytes, inflammation, oxidative stress, cartilage development, and chondrogenic differentiation. Differential expression of circRNAs was also observed in the synovium and subchondral bone in the OA joint. In terms of mechanism, existing studies have mainly found that circRNA adsorbs miRNA through the ceRNA mechanism, and a few studies have found that circRNA can serve as a scaffold for protein reactions. In terms of clinical transformation, circRNAs are considered promising biomarkers, but no large cohort has tested their diagnostic value. Meanwhile, some studies have used circRNAs loaded in extracellular vesicles for OA precision medicine. However, there are still many problems to be solved in the research, such as the role of circRNA in different OA stages or OA subtypes, the construction of animal models of circRNA knockout, and more research on the mechanism of circRNA. In general, circRNAs have a regulatory role in OA and have particular clinical potential, but further studies are needed in the future.

The emerging role of lncRNAs in osteoarthritis development and potential therapy

“…It is known that circRNAs form a covalently closed loop and regulate gene expression, leading to governing cellular processes. Accumulating evidence has suggested that circRNAs play a critical role in osteoarthritis initiation and progression ( Wu and Zou, 2021 ; Wang et al, 2023 ; Li and Lu, 2023 ; Xue et al, 2023 ).…”

Spatial distribution proteoglycans articular cartilage of femoral condyles and tibial plateau in experimental osteoarthritis in rats

“…В состав легочного сурфактанта человека входят 4 белка: SP-A, SP-B, SP-C, SP-D. Согласно нашим предыдущим исследованиям, на основе анализа структурной гомологии, было определено, что на лубрикативные свойств синовиальной жидкости могут оказывать влияние только SP-B, SP-C, SP-D [5]. Также особенности строения суставного хряща и наличие протеогликанов обеспечивают ему определенную защиту к избыточным механическим нагрузкам [6]. Среди протеогликанов особый интерес представляют такие белки, как лубрицин и аггрекан, поскольку именно их баланс, по современным представлениям, определяет прочностные и трибологические свойства суставного хряща [7].…”