Rat Sciatic Nerve Axoplasm Proteome Is Enriched with Ribosomal Proteins during Regeneration Processes

Area of Science:

• Neuroscience
• Molecular Biology
• Proteomics

Background:

• Axons are vital nerve cell components, especially long in peripheral nerves.
• Axon injury involves complex processes like transport and local protein synthesis.
• In vivo studies are crucial but challenging for analyzing axonal changes.

Purpose of the Study:

• To investigate in vivo axonal protein changes after injury using proteomics.
• To identify newly synthesized proteins in axons following injury.
• To explore the role of ribosomal proteins in axonal injury and repair.

Main Methods:

• Adapted osmotic ex vivo axoplasm isolation from adult rat sciatic nerves.
• Performed label-free quantitative proteomics on isolated axoplasm before and after injury.
• Utilized MS/MS-BONCAT to detect newly synthesized proteins in vivo.

Main Results:

• Identified 2087 protein groups in axoplasm, with translation machinery and microtubule-associated proteins being overrepresented.
• Observed an increase in ribosomal proteins (73 detected) in axoplasm post-injury, but not in whole sciatic nerves.
• Detected 42 newly synthesized protein groups in vivo using MS/MS-BONCAT.

Conclusions:

• Proteomics profiling of isolated axoplasm is effective for in vivo axonal research.
• Ribosomal proteins show increased abundance after axonal injury, highlighting their potential importance.
• Local protein synthesis in axons is a significant process, especially during injury response.