Circulating miRNAs are associated with successful bone regeneration.

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Molecular Biology

Background:

• Bone healing is a complex biological process crucial for skeletal integrity.
• Disruptions in bone healing can lead to delayed or non-union fractures, impacting patient health.
• MicroRNAs (miRNAs) are small non-coding RNAs involved in cellular processes, including bone remodeling, and are stable in biofluids, making them potential diagnostic markers.

Purpose of the Study:

• To investigate the dynamic changes in circulating miRNAs during bone healing in a rat calvaria defect model.
• To identify specific miRNA profiles associated with successful bone regeneration.
• To evaluate the potential of circulating miRNAs as biomarkers for predicting bone healing outcomes.

Main Methods:

• Standardized calvaria defects were created in Wistar rats and treated with collagen hydroxyapatite (CHA) scaffolds, with variations including BMP2 plasmid, extracellular vesicles, or empty defects.
• Microcomputed tomography (microCT) and histological analyses were performed at 1, 4, and 8 weeks post-surgery.
• Plasma samples were collected longitudinally, and circulating miRNAs were analyzed using next-generation sequencing.

Main Results:

• Despite high variability and no significant differences between treatment groups in bone regeneration, distinct circulating miRNA expression patterns were observed.
• Circulating miRNA profiles differed between rats with high and low regenerative activity.
• miR-133-3p and miR-375-3p were identified as the top upregulated and downregulated miRNAs, respectively, in animals with strong regeneration.

Conclusions:

• Circulating miRNA expression patterns are associated with the success or failure of bone regeneration, independent of the specific treatment applied.
• Further investigation is warranted to validate these miRNAs as predictive biomarkers for successful bone healing.