scholarly journals Mitogen-Activated Protein Kinase Pathways Following Traumatic Brain Injury

2011 ◽  
Vol 02 (03) ◽  
pp. 208-216 ◽  
Author(s):  
Naoki Otani ◽  
Hiroshi Nawashiro ◽  
Kimihiro Nagatani ◽  
Satoru Takeuchi ◽  
Hiroaki Kobayashi ◽  
...  
2002 ◽  
Vol 22 (3) ◽  
pp. 327-334 ◽  
Author(s):  
Naoki Otani ◽  
Hiroshi Nawashiro ◽  
Shinji Fukui ◽  
Namiko Nomura ◽  
Akiko Yano ◽  
...  

Mitogen-activated protein kinases, which play a crucial role in signal transduction, are activated by phosphorylation in response to a variety of mitogenic signals. In the present study, the authors used Western blot analysis and immunohistochemistry to show that phosphorylated extracellular signal-regulated protein kinase (p-ERK) and c-Jun NH(2)-terminal kinase (p-JNK), but not p38 mitogen-activated protein kinase, significantly increased in both the neurons and astrocytes after traumatic brain injury in the rat hippocampus. Different immunoreactivities of p-ERK and p-JNK were observed in the pyramidal cell layers and dentate hilar cells immediately after traumatic brain injury. Immunoreactivity for p-JNK was uniformly induced but was only transiently induced throughout all pyramidal cell layers. However, strong immunoreactivity for p-ERK was observed in the dentate hilar cells and the damaged CA3 neurons, along with the appearance of pyknotic morphologic changes. In addition, immunoreactivity for p-ERK was seen in astrocytes surrounding dentate and CA3 pyramidal neurons 6 hours after traumatic brain injury. These findings suggest that ERK and JNK but not p38 cascades may be closely involved in signal transduction in the rat hippocampus after traumatic brain injury.


2002 ◽  
Vol 22 (4) ◽  
pp. 444-452 ◽  
Author(s):  
Tatsuro Mori ◽  
Xiaoying Wang ◽  
Jae-Chang Jung ◽  
Toshihisa Sumii ◽  
Aneesh B. Singhal ◽  
...  

The authors provide the first in vitro and in vivo evidence that perturbations in mitogen-activated protein kinase (MAPK) signal-transduction pathways are involved in the pathophysiology of traumatic brain injury. In primary rat cortical cultures, mechanical trauma induced a rapid and selective phosphorylation of the extracellular signal-regulated kinase (ERK) and p38 kinase, whereas there was no detectable change in the c-jun N-terminal kinase (JNK) pathway. Treatment with PD98059, which inhibits MAPK/ERK 1/2, the upstream activator of ERK, significantly increased cell survival in vitro. The p38 kinase and JNK inhibitor SB203580 had no protective effect. Similar results were obtained in vivo using a controlled cortical impact model of traumatic injury in mouse brain. Rapid and selective upregulation occurred in ERK and p38 pathways with no detectable changes in JNK. Confocal immunohistochemistry showed that phospho-ERK colocalized with the neuronal nuclei marker but not the astrocytic marker glial fibrillary acidic protein. Inhibition of the ERK pathway with PD98059 resulted in a significant reduction of cortical lesion volumes 7 days after trauma. The p38 kinase and JNK inhibitor SB203580 had no detectable beneficial effect. These data indicate that critical perturbations in MAPK pathways mediate cerebral damage after acute injury, and further suggest that ERK is a novel therapeutic target in traumatic brain injury.


2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Yuqin Ye ◽  
Zhenyu Zhao ◽  
Hongyu Xu ◽  
Xin Zhang ◽  
Xinhong Su ◽  
...  

Among sphingosine 1-phosphate receptors (S1PRs) family, S1PR1 has been shown to be the most highly expressed subtype in neural stem cells (NSCs) and plays a crucial role in the migratory property of NSCs. Recent studies suggested that S1PR1 was expressed abundantly in the hippocampus, a specific neurogenic region in rodent brain for endogenous neurogenesis throughout life. However, the potential association between S1PR1 and neurogenesis in hippocampus following traumatic brain injury (TBI) remains unknown. In this study, the changes of hippocampal S1PR1 expression after TBI and their effects on neurogenesis and neurocognitive function were investigated, focusing on particularly the extracellular signal-regulated kinase (Erk) signaling pathway which had been found to regulate multiple properties of NSCs. The results showed that a marked upregulation of S1PR1 occurred with a peak at 7 days after trauma, revealing an enhancement of proliferation and neuronal differentiation of NSCs in hippocampus due to S1PR1 activation. More importantly, it was suggested that mitogen-activated protein kinase-Erk kinase (MEK)/Erk cascade was required for S1PR1-meidated neurogenesis and neurocognitive recovery following TBI. This study lays a preliminary foundation for future research on promoting hippocampal neurogenesis and improving TBI outcome.


2013 ◽  
Vol 41 (9) ◽  
pp. e223-e232 ◽  
Author(s):  
Woon Yong Kwon ◽  
Gil Joon Suh ◽  
Kyung Su Kim ◽  
Hui Jai Lee ◽  
Ki Young Jeong ◽  
...  

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