Spatiotemporal expression of Dexras1 after spinal cord transection in rats.
Dexras1, a brain-enriched member of the Ras subfamily of GTPases, as a novel physiologic nitric oxide (NO) effector, anchor neuronal nitric oxide synthase (nNOS) that increased after spinal cord injury (SCI), to specific targets to enhance NO signaling, and is strongly and rapidly induced during treatment with dexamethasone. It is unknown how the central nervous system (CNS) trauma affects the expression of Dexras1. Here we used spinal cord transection (SCT) model to detect expression of Dexras1 at mRNA and protein level in spinal cord homogenates by real-time PCR and Western blot analysis. The results showed that Dexras1 mRNA upregulated at 3 day, 5 day, and 7 day significantly (P < 0.05) that was consistent with the protein level except at 7 day. Immunofluorescence revealed that both neurons and glial cells showed Dexras1 immunoreactivivty (IR) around SCT site, but the proportion is different. Importantly, injury-induced expression of Dexras1 was co-labeled by caspase-3 (apoptotic marker) and Tau-1 (marker for pathological oligodendrocyte). Furthermore, colocalization of Dexras1, carboxy-terminal PSD95/DLG/ZO-1 (PDZ) ligand of nNOS (CAPON) and nNOS was observed in neurons and glial cells, supporting the existence of ternary complexes in this model. Thus, the results that the transient high expression of Dexras1 which localized in apoptotic neurons and pathological oligodendrocytes might provide new insight into the secondary response after SCT.
Li
Xin
X
The Jiangsu Province Key Laboratory of Neuroregeneration, Nantong University, 19 Qi-xiu Road, Nantong, Jiangsu 226001, China.
Cheng
Chun
C
Fei
Min
M
Gao
Shangfeng
S
Niu
Shuqiong
S
Chen
Mengling
M
Liu
Yonghua
Y
Guo
Zhiqin
Z
Wang
Haibo
H
Zhao
Jian
J
Yu
Xiaowei
X
Shen
Aiguo
A
D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism; D000818:Animals; D017209:Apoptosis / Q000235:genetics; D015415:Biomarkers / Q000378:metabolism; D020169:Caspases / Q000378:metabolism; D005786:Gene Expression Regulation; D008297:Male; D052248:Nitric Oxide Synthase Type I / Q000378:metabolism; D009836:Oligodendroglia / Q000378:metabolism; D010919:Placebos; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013119:Spinal Cord Injuries / Q000235:genetics* / Q000378:metabolism; D013904:Thoracic Vertebrae / Q000293:injuries / Q000378:metabolism; D014018:Tissue Distribution; D018631:ras Proteins / Q000235:genetics* / Q000378:metabolism*
D048868:Adaptor Proteins, Signal Transducing; D015415:Biomarkers; C488082:NOS1AP protein, rat; D010919:Placebos; D012333:RNA, Messenger; C528215:Rasd1 protein, rat; D052248:Nitric Oxide Synthase Type I; D020169:Caspases; D018631:ras Proteins