Dynamic regulation of SCG10 in regenerating axons after injury

• Published in: Experimental neurology 2014-02, Vol.252, p.1-11
• Main Authors: Shin, Jung Eun, Geisler, Stefanie, DiAntonio, Aaron
• Format: Article
• Language: English
• Subjects: Animals; Axon regeneration; Axons - metabolism; Axons - pathology; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Biological and medical sciences; Calcium-Binding Proteins; Cells, Cultured; Choline O-Acetyltransferase - genetics; Choline O-Acetyltransferase - metabolism; Disease Models, Animal; Dorsal root ganglia (DRG); Embryo, Mammalian; Ganglia, Spinal - cytology; GAP-43 Protein - metabolism; Gene Expression Regulation - physiology; Injuries of the nervous system and the skull. Diseases due to physical agents; Intracellular Signaling Peptides and Proteins - genetics; Intracellular Signaling Peptides and Proteins - metabolism; Luminescent Proteins - genetics; Luminescent Proteins - metabolism; Marker of regenerating axon; Medical sciences; Mice; Mice, Inbred C57BL; Mice, Transgenic; Microfilament Proteins - genetics; Nerve Regeneration - physiology; Nerve repair; Neurology; Nicotinamide-Nucleotide Adenylyltransferase - genetics; Nicotinamide-Nucleotide Adenylyltransferase - metabolism; NMNAT; Sciatic Nerve - metabolism; Sciatic Nerve - pathology; Sciatic Neuropathy - metabolism; Sciatic Neuropathy - physiopathology; Stathmin; STMN2; Time Factors; Traumas. Diseases due to physical agents; Tubulin - metabolism
• ISSN: 0014-4886; 1090-2430
• DOI: 10.1016/j.expneurol.2013.11.007

Peripheral axons can re-extend robustly after nerve injury. Soon after a nerve crush regenerating axons grow through the nerve segment distal to the lesion in close proximity to distal axons that are still morphologically and molecularly preserved. Hence, following the progress of regenerating axons necessitates markers that can distinguish between regenerating and degenerating axons. Here, we show that axonal levels of superior cervical ganglion 10 (SCG10) are dynamically regulated after axonal injury and provide an efficient method to label regenerating axons. In contrast to the rapid loss of SCG10 in distal axons (Shin et al., 2012b), we report that SCG10 accumulates in the proximal axons within an hour after injury, leading to a rapid identification of the lesion site. The increase in SCG10 levels is maintained during axon regeneration after nerve crush or nerve repair and allows for more selective labeling of regenerating axons than the commonly used markers growth-associated protein 43 (GAP43) and YFP. SCG10 is preferentially expressed in regenerating sensory axons rather than motor axons in the sciatic nerve. In a mouse model of slow Wallerian degeneration, SCG10 labeling remains selective for regenerating axons and allows for a quantitative analysis of delayed regeneration in this mutant. Taken together, these data demonstrate the utility of SCG10 as an efficient and selective marker of sensory axon regeneration. •SCG10 levels are increased in proximal axons promptly after axonal injury.•SCG10 is a selective marker for injured regenerating axons.•SCG10 is a more selective marker of regenerating axons than GAP43 or YFP.•SCG10 is expressed preferentially in regenerating sensory axons.•SCG10 labeling detects delayed regeneration in a model of slow axon degeneration.