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Updated: Jun 2, 2026
Controlled Cortical Impact Model for Traumatic Brain Injury
Published on: August 5, 2014
Upregulation of p21-activated Kinase 6 in rat brain cortex after traumatic brain injury
1Department of Neurosurgery, Affiliated Hospital of Nantong University, Nantong University, 226001 Nantong, People's Republic of China.
Abstract:
p21-activated Kinase 6 (PAK6) is a serine/threonine kinase belonging to the p21-activated kinase (PAK) family. PAK kinases are well-known regulators of a wide variety of cellular functions, including regulation of cytoskeleton rearrangement, cell survival, apoptosis and the mitogen-activated protein kinase signaling pathway. To elucidate the expressions and possible functions of PAK6 in central nervous system (CNS) lesion and repair, we performed a traumatic brain injury (TBI) model in adult rats. Western blot analysis revealed that PAK6 level significantly increased at day 3 after damage, and then declined during the following days. Besides, double immunofluorescence staining showed PAK6 was primarily expressed in the neurons and a few of glial cells in the normal group. While after injury, the expression of PAK6 was increased significantly in the astrocytes and neurons, and the astrocytes had largely proliferated. We also examined the expression of proliferating cell nuclear antigen (PCNA) whose change was correlated with the expression of PAK6. Importantly, double immunofluorescence staining revealed that cell proliferation evaluated by PCNA appeared in many PAK6-expressing cells at day 3 after injury. In addition, injury-induced expression of PAK6 was co-labeled by active caspase-3 during neuronal apoptosis after injury. Collectively, we hypothesized PAK6 may play important roles in CNS pathophysiology after TBI and further research is needed to have a good understanding of its function and mechanism.
Insights
p21-activated Kinase 6 (PAK6) expression increases after traumatic brain injury (TBI) in rats, correlating with cell proliferation and apoptosis. PAK6 may play a key role in central nervous system repair after TBI.
Area of Science:
- Neuroscience
- Molecular Biology
- Cell Biology
Background:
- p21-activated Kinase 6 (PAK6) is a serine/threonine kinase involved in cellular functions like cytoskeleton regulation, cell survival, and apoptosis.
- PAK kinases are crucial regulators in various signaling pathways, including the mitogen-activated protein kinase pathway.
Purpose of the Study:
- To investigate the expression and potential roles of PAK6 in the central nervous system (CNS) following traumatic brain injury (TBI) and during the repair process.
- To understand the cellular localization and changes in PAK6 expression in response to TBI.
Main Methods:
- A traumatic brain injury (TBI) model was established in adult rats.
- Western blot analysis was used to quantify PAK6 protein levels over time post-injury.
- Double immunofluorescence staining was employed to determine the cellular localization of PAK6 and its co-expression with markers of proliferation (PCNA) and apoptosis (active caspase-3).
Main Results:
- PAK6 protein levels significantly increased by day 3 after TBI, subsequently declining.
- In normal CNS tissue, PAK6 was mainly found in neurons and some glial cells.
- Following TBI, PAK6 expression elevated in astrocytes and neurons, coinciding with significant astrocyte proliferation.
- PAK6 expression was positively correlated with proliferating cell nuclear antigen (PCNA) expression, indicating involvement in cell proliferation.
- Injury-induced PAK6 expression was co-localized with active caspase-3, suggesting a role in neuronal apoptosis.
Conclusions:
- PAK6 expression is dynamically regulated in the CNS following TBI.
- PAK6 appears to be involved in both astrocyte proliferation and neuronal apoptosis after CNS injury.
- These findings suggest that PAK6 plays a significant role in the pathophysiology of TBI and warrants further investigation into its precise functions and mechanisms in CNS repair.
