Circular RNAs as potential regulators in bone remodeling: a narrative review

Osteoporosis and other bone-remodeling disorders affect millions globally. Bone remodeling involves a balance between bone formation and resorption. This balance is maintained by osteoblasts and osteoclasts. When disrupted, the result is disease. Non-coding RNAs have emerged as regulators in this process. Circular RNAs (circRNAs) are a subclass of non-coding RNAs. Their role in bone homeostasis is not yet fully understood. This gap motivated researchers to explore circRNAs in bone-related signaling. Prior research has shown circRNAs influence other cellular functions. However, their specific impact on bone remodeling remains unclear.

This review aims to examine the role of circRNAs in bone remodeling. The focus is on osteogenesis and osteoclastogenesis. The study explores how circRNAs regulate key signaling pathways. These pathways include BMP, TGF-β, Wnts, and RANKL/OPG. The researchers sought to identify circRNAs involved in bone homeostasis. They also aimed to understand how these molecules contribute to disease. The motivation stems from the need for better diagnostic and therapeutic tools. This study provides a comprehensive overview of current findings.

The researchers conducted a narrative review of existing literature. They searched six databases, including PubMed and Embase. No language restrictions were applied to the search. The cutoff date for inclusion was June 2021. The focus was on circRNAs in bone remodeling. The study included works on signaling pathways and disease mechanisms. The researchers analyzed circRNA functions in osteoblasts and osteoclasts. They evaluated how these molecules affect bone homeostasis and disease.

Many circRNAs regulate bone formation and resorption. They influence BMP, TGF-β, Wnts, and RANKL/OPG pathways. These pathways are critical for osteoblast and osteoclast function. CircRNAs modulate these pathways through diverse mechanisms. Some circRNAs promote osteogenesis while others support osteoclast differentiation. Aberrant circRNA activity is linked to osteoporosis and osteonecrosis. The study found associations between circRNAs and bone disease markers. These findings suggest circRNAs may serve as diagnostic or therapeutic targets.

The review highlights circRNAs as regulators of bone homeostasis. Their role in osteogenesis and osteoclastogenesis is well-supported. The evidence suggests circRNAs influence key signaling pathways. These molecules may contribute to the development of bone disorders. The findings support further investigation into circRNA functions. The authors propose circRNAs could aid in diagnosing and treating bone diseases. No prior work had resolved the full scope of circRNA involvement. The study provides a foundation for future research in this area.