Temporal Proteome Profiling of Anterior Cruciate Ligament Tear Remnants: Secretory Proteins in the Acute Phase Potentially Promote Tissue Repair

Previous studies reported that preserving the anterior cruciate ligament (ACL) remnants following ACL rupture during reconstruction surgery could promote graft healing. However, the temporal proteomic expression of ACL remnants remains unclear. Based on previous reports, we have redefined the initial 6 weeks following ACL rupture as the acute phase and the subsequent 6 weeks to 6 months as the subacute phase. High-throughput proteomic sequencing on ACL remnants from the two groups was utilized. Our study unveiled a total of 381 differential expression proteins (DEPs), with 136 upregulated and 245 downregulated proteins in the acute phase. By intersecting these findings with secretory protein databases, we identified 26 upregulated secretory proteins and 19 downregulated in the acute phase. The upregulation of MMP9 and VTN and the downregulation of COL1A1 and POSTN in the acute phase were further confirmed by immunohistochemistry. These findings suggest that the elevated expression of secretory proteins in the acute phase may play crucial roles in promoting cell proliferation, angiogenesis, and tissue repair of the graft. This study not only enhances our understanding of repair mechanisms in ACL remnant preservation but also provides a theoretical foundation for guiding rational clinical surgical timing.