Insulin-like growth factor binding protein (IGFBP6) is a cross-species tendon marker.

The research identifies Insulin-like growth factor binding protein 6 (IGFBP6) as a universal marker across different species for tendon identification, which could be beneficial for cellular differentiation in tissue bioengineering for tendon repair.

Background

• The need for this research arises from the challenges in managing tendon injuries which often result in imperfect healing, leaving the tendon with suboptimal functionality.
• For bioengineering tissues that can enhance tendon healing and improve function, there is a previously unidentified requirement for specific markers that indicate different stages of tendon differentiation.

Methodology

• The researchers have used gene expression profiling of rat tendon and cartilage in both whole-tissue samples and primary tenocytes and chondrocytes, using two independent microarray platforms.
• Genes that exhibited high expression correlation across the two assays were further validated by quantitative reverse transcription polymerase chain reaction (qRT-PCR) relative to cartilage and muscle in the rat.

Results

• Five genes (ASPN, ECM1, IGFBP6, TNMD, THBS4) with the highest tendon-related expression in the validation experiment were further evaluated by qRT-PCR in ovine, equine, and human tissue.
• These identified tendon markers showed variable expression profiles across different species.
• However, the study identified Insulin-like growth factor binding protein 6 (IGFBP6) as a consistent tendon marker across all species.
• Further analysis in equines revealed that IGFBP6 expression remained unaffected by age or tendon function but diminished in areas subjected to higher compressive forces.

Conclusions

• IGFBP6 potentially serves as a robust cross-species identifier of tendons, beneficial in assessing tendon physiology and guided differentiation of cells towards functional tenocytes during tissue bioengineering applications.