Bioinformatics and Microarray Analysis of miRNAs in Aged Female Mice Model Implied New Molecular Mechanisms for
Bing He1,2, Zong-Kang Zhang3, Jin Liu4,5
1Institute for Advancing Translational Medicine in Bone & Joint Diseases, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, China. hebinghb@gmail.com.
Abstract:
Impaired fracture healing in aged females is still a challenge in clinics. MicroRNAs (miRNAs) play important roles in fracture healing. This study aims to identify the miRNAs that potentially contribute to the impaired fracture healing in aged females. Transverse femoral shaft fractures were created in adult and aged female mice. At post-fracture 0-, 2- and 4-week, the fracture sites were scanned by micro computed tomography to confirm that the fracture healing was impaired in aged female mice and the fracture calluses were collected for miRNA microarray analysis. A total of 53 significantly differentially expressed miRNAs and 5438 miRNA-target gene interactions involved in bone fracture healing were identified. A novel scoring system was designed to analyze the miRNA contribution to impaired fracture healing (RCIFH). Using this method, 11 novel miRNAs were identified to impair fracture healing at 2- or 4-week post-fracture. Thereafter, function analysis of target genes was performed for miRNAs with high RCIFH values. The results showed that high RCIFH miRNAs in aged female mice might impair fracture healing not only by down-regulating angiogenesis-, chondrogenesis-, and osteogenesis-related pathways, but also by up-regulating osteoclastogenesis-related pathway, which implied the essential roles of these high RCIFH miRNAs in impaired fracture healing in aged females, and might promote the discovery of novel therapeutic strategies.
Insights
Impaired fracture healing in aged females is linked to specific microRNAs (miRNAs). This study identified novel miRNAs that hinder bone repair by affecting key cellular pathways, offering potential therapeutic targets.
Area of Science:
- Biomedical research
- Molecular biology
- Gerontology
Background:
- Fracture healing is often impaired in aged individuals, posing clinical challenges.
- MicroRNAs (miRNAs) are critical regulators of biological processes, including bone healing.
- Understanding miRNA roles in age-related fracture complications is essential for developing new treatments.
Purpose of the Study:
- To identify specific microRNAs (miRNAs) contributing to impaired fracture healing in aged female mice.
- To analyze the functional impact of these miRNAs on bone repair pathways.
Main Methods:
- Induction of femoral shaft fractures in adult and aged female mice.
- Micro computed tomography (micro-CT) for assessing fracture healing progression.
- miRNA microarray analysis and bioinformatics to identify differentially expressed miRNAs and their targets.
- Development of a novel scoring system (RCIFH) to quantify miRNA contribution to impaired healing.
Main Results:
- Confirmed impaired fracture healing in aged female mice compared to adults.
- Identified 53 significantly differentially expressed miRNAs and 5438 miRNA-target gene interactions.
- Discovered 11 novel miRNAs that impair fracture healing at 2 or 4 weeks post-fracture using the RCIFH system.
- Functional analysis revealed that high RCIFH miRNAs down-regulate angiogenesis, chondrogenesis, and osteogenesis while up-regulating osteoclastogenesis.
Conclusions:
- Specific novel miRNAs significantly contribute to impaired fracture healing in aged females.
- These miRNAs disrupt bone healing by modulating critical cellular pathways.
- The findings highlight potential therapeutic targets for improving fracture repair in the elderly.
