Spatiotemporal expression of PSD-95 and nNOS after rat sciatic nerve injury.
Neuronal nitric oxide synthase (nNOS) has been implicated to influence peripheral nerve lesion and regeneration. Post-synaptic density-95 (PSD-95) is one of nNOS-anchoring proteins and plays an important role in specifying the sites of reaction of NO in nervous system. Here we established a rat sciatic nerve crush (SNC) model to examine the spatiotemporal expression of PSD-95 and nNOS. At gene levels, PSD-95 mRNA diminished shortly after crush, and significantly elevated from 2 days to 2 weeks, whereas nNOS decreased progressively post-operation, reached the valley at 1 day, and markedly up-regulated from 1 to 2 weeks after SNC. The expression of both molecules returned to the control level at 4 weeks post-injury. At protein levels, PSD-95 and nNOS underwent the similar changes as their gene expression except for a time lag during up-regulating. At their peak expression, PSD-95 co-labeled with nNOS in Schwann cells (SCs) of sciatic nerve within 0.5 mm from the lesion site, but had few colocalization in axons. In addition, the interaction between PSD-95 and nNOS enhanced significantly at 2 weeks after SNC. These results suggest a correlation of PSD-95 up-regulation with nNOS in reactive SCs of crushed sciatic nerve, which may lead to understanding the function of PSD-95 during peripheral nerve regeneration.
Gao
Shangfeng
S
The Jiangsu Province Key Laboratory of Neuroregeneration, Nantong University, Nantong 226001, China.
Fei
Min
M
Cheng
Chun
C
Yu
Xiaowei
X
Chen
Mengling
M
Shi
Shuxian
S
Qin
Jing
J
Guo
Zhiqin
Z
Shen
Aiguo
A
D000818:Animals; D000076122:Disks Large Homolog 4 Protein; D005260:Female; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D009409:Nerve Crush; D009416:Nerve Regeneration; D052248:Nitric Oxide Synthase Type I / Q000235:genetics / Q000378:metabolism*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012584:Sciatic Nerve / Q000166:cytology / Q000293:injuries* / Q000378:metabolism*
D000076122:Disks Large Homolog 4 Protein; C501449:Dlg4 protein, rat; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D052248:Nitric Oxide Synthase Type I