Comparison of blood-nerve barrier disruption and matrix metalloprotease-9 expression in injured central and peripheral nerves in mice.
To investigate the involvement of blood-born factors and extracellular proteases in axonal degeneration and regeneration in both PNS and CNS, we directly compared the differences of blood-nerve barrier (BNB) disruption and matrix metalloprotease-9 (MMP-9) induction between the sciatic nerve and optic nerve after crush injury in the same animal. In sciatic nerve, BNB disruption, fibrin(ogen) deposition and MMP-9 expression were observed only in the first week following injury. Neurofilament (NF) immunoreactivity dramatically decreased in the first 2 days, gradually recovered to the normal levels by day 28. In contrast, the immunoglobulin G deposits spanned from 4 h to 28 days in crushed optic nerves. Fibrin(ogen) deposition was only observed in the first 2 days, while MMP-9 induction did not occur until a week after injury but lasted for 3 weeks in the crushed optic nerves. The NF immunoreactivity did not change much until day 7 and almost completely disappeared on day 28. The decrease of NF immunoreactivity coincided with the induction of MMP-9 after optic nerve crush. These results show that BNB disruption and MMP-9 induction are differentially regulated in the PNS and CNS after injuries, and they may contribute to the different regeneration capacities of the two systems.
Liu
Li-Yun
LY
Department of Anatomy, Histology and Embryology, Shanghai Medical School, Fudan University, 200032 Shanghai, China.
Zheng
Hua
H
Xiao
Hong-Lei
HL
She
Zhen-Jue
ZJ
Zhao
Shu-Min
SM
Chen
Zu-Lin
ZL
Zhou
Guo-Min
GM
D000818:Animals; D001812:Blood-Brain Barrier / Q000201:enzymology* / Q000473:pathology; D005109:Extracellular Matrix / Q000201:enzymology; D007074:Immunoglobulin G / Q000378:metabolism; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D009409:Nerve Crush; D016900:Neurofilament Proteins / Q000378:metabolism; D009900:Optic Nerve / Q000201:enzymology* / Q000473:pathology; D020221:Optic Nerve Injuries / Q000378:metabolism* / Q000473:pathology; D012584:Sciatic Nerve / Q000201:enzymology* / Q000293:injuries* / Q000473:pathology
D007074:Immunoglobulin G; D016900:Neurofilament Proteins; D020780:Matrix Metalloproteinase 9; C501830:Mmp9 protein, mouse