Secretome Profiling in Axon Regeneration: Emerging Techniques and Therapeutic Translation

ABSTRACT The secretome refers to the in vivo ensemble of molecular entities that are found in interstitial spaces. It is then the mere secreted products of the cells, as all biomolecules in the interstitial cellular spaces also undergo modifications. The fractionated secretome may hold potential as a cell‐free therapy option due to its role in tissue regeneration and intercellular communication. The dynamic collection of bioactive molecules, including cytokines, growth factors, lipids, nucleic acids, and extracellular vesicles, allows the secretome to influence cellular behavior and modulate physiological and pathological processes. How the composition of secretomes differs in different cell types remains unknown. In this review, we will be exploring the role of secretomes in axon regeneration both in the peripheral nervous system (PNS) and central nervous system (CNS), specifically within optic nerve regeneration. We present here the techniques available for secretome identification and quantification to provide direction for future studies and expand our knowledge on secretome composition, paving the way for the development of focused cell‐type targeted therapies for axon regeneration.