Enhanced expression of heat shock protein 27 is correlated with axonal regeneration in mature retinal ganglion cells.
The small heat shock protein, Hsp27, promotes axonal regeneration in peripheral neurons; however, an analogous role in the central nervous system has not been described. This study examined the relationship between Hsp27 expression and regeneration in mature retinal ganglion cells (RGCs). Adult rat optic nerves were transected and exposed to peripheral nerve autografts to stimulate regeneration of cut RGC axons. There was a five-fold increase in the Hsp27-positive fraction of RGCs that extended new axons into the graft when compared with those that survived injury but did not regenerate (30% versus 6% respectively, P = 0.001). Hsp27 protein was located throughout somata and neuritic processes, and there was a significant positive correlation between Hsp27 expression and axonal regeneration in injured neurons (R = 0.92, P < 0.0001). These findings are consistent with the growth-associated role of Hsp27 demonstrated in peripheral neurons and suggest that Hsp27 may mediate similar physiological functions in the central nervous system.
Department of Anatomy & Neurobiology, Dalhousie University, Halifax, NS, Canada B3H 4H7.
Matthew O
MO
Hebb
Tanya L
TL
Myers
David B
DB
Clarke
D000818:Animals; D002452:Cell Count / Q000379:methods; D005260:Female; D006360:Heat-Shock Proteins / Q000378:metabolism*; D007150:Immunohistochemistry / Q000379:methods; D016014:Linear Models; D009416:Nerve Regeneration / Q000502:physiology*; D020221:Optic Nerve Injuries / Q000378:metabolism / Q000503:physiopathology / Q000601:surgery; D010525:Peripheral Nerves / Q000637:transplantation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012165:Retinal Ganglion Cells / Q000502:physiology*; D013266:Stilbamidines; D014182:Transplantation, Autologous / Q000502:physiology
C049774:2-hydroxy-4,4'-diamidinostilbene, methanesulfonate salt; D006360:Heat-Shock Proteins; D013266:Stilbamidines