Genomic clues to secondary injury mechanisms in brain trauma
Author: Gertten, Christina von
Date: 2006-09-22
Location: Föreläsningssalen, Thoraxaulan, N2:U1 kulvertplan, Karolinska Universitetssjukhuset
Time: 09.15
Department: Institutionen för klinisk neurovetenskap / Department of Clinical Neuroscience
View/ Open:
Thesis (735.8Kb)
Abstract
Traumatic brain injury (TBI) is a heterogenous disease that can lead to persistent disability or death. The immediate mechanical disruption of brain tissue is followed by a phase of secondary brain injury. During this phase TBI challenges clinical interventions due to its complexity. Increased knowledge is needed about the operating molecules and their timewindows. We used cerebral cortical contusions by weight drop and experimental depolarisation, in order to analyse molecular and genetic responses. Alterations in gene expression were studied by microarrays, RTPCR, in situ hybridisation and immunohistochemistry.
Nestin is an intermediate filament, expressed in CNS progenitor cells during embryogenesis, but restricted to residing stemcells in adults. Depolarisation induced nestin expression in astrocytes along the ipsilateral cortex. A blockade by the MK-801 reduced nestin expression. The nestin expression in reactive astrocytes is interesting since they form the glial scar.
Matrix metalloproteinases (MMPs) and their inhibitors TIMPs, determine extracellular matrix turnover and cause overgrowth or disruption when disturbed. We found a time-dependent increase of neuronal TIMP-1 and MMP-9 expression in the ipsilateral cortex after depolarisation and contusion. The early expression of TIMP-1 could be a MMP-9 independent protective response to damage. TIMP-1 and MMP-9 are likely to participate in the tissue reorganisation or neuroprotection.
After experimental contusion early and delayed genomic responses were significantly different for genes involved in transcription, cell communication, cell proliferation, cell-death and metabolism. In the early phase genes involved in "transcription" and "cell-death" were prominent, while "immune response" and "proteolysis" dominated the delayed phase. Osteopontin and the CD44 receptor are involved in inflammation, and were locally upregulated at the impact site. Genes of the calcium signaling pathway i.a. hippocalcin and VILIP-1, were suppressed while genes of the complement and coagulation pathways were upregulated. Depolarisation and experimental contusion largely shared genomic responses. NMDA receptor blockade after depolarisation abolished the regulated genes to a larger extent than after contusion.
Genes for nestin, MMP-9, TIMP-1, osteopontin and CD44 were similarly regulated in both models. Almost all depolarisation induced effects were detected in traumatically injured animals, while some post-traumatic changes appeared to be independent of depolarisation. The findings corroborated that depolarisation was a mechanism in experimental trauma. Microarrays could be used to produce a comprehensive image of regulated genes at a specific time or to allow an unbiased search for relevant events.
Nestin is an intermediate filament, expressed in CNS progenitor cells during embryogenesis, but restricted to residing stemcells in adults. Depolarisation induced nestin expression in astrocytes along the ipsilateral cortex. A blockade by the MK-801 reduced nestin expression. The nestin expression in reactive astrocytes is interesting since they form the glial scar.
Matrix metalloproteinases (MMPs) and their inhibitors TIMPs, determine extracellular matrix turnover and cause overgrowth or disruption when disturbed. We found a time-dependent increase of neuronal TIMP-1 and MMP-9 expression in the ipsilateral cortex after depolarisation and contusion. The early expression of TIMP-1 could be a MMP-9 independent protective response to damage. TIMP-1 and MMP-9 are likely to participate in the tissue reorganisation or neuroprotection.
After experimental contusion early and delayed genomic responses were significantly different for genes involved in transcription, cell communication, cell proliferation, cell-death and metabolism. In the early phase genes involved in "transcription" and "cell-death" were prominent, while "immune response" and "proteolysis" dominated the delayed phase. Osteopontin and the CD44 receptor are involved in inflammation, and were locally upregulated at the impact site. Genes of the calcium signaling pathway i.a. hippocalcin and VILIP-1, were suppressed while genes of the complement and coagulation pathways were upregulated. Depolarisation and experimental contusion largely shared genomic responses. NMDA receptor blockade after depolarisation abolished the regulated genes to a larger extent than after contusion.
Genes for nestin, MMP-9, TIMP-1, osteopontin and CD44 were similarly regulated in both models. Almost all depolarisation induced effects were detected in traumatically injured animals, while some post-traumatic changes appeared to be independent of depolarisation. The findings corroborated that depolarisation was a mechanism in experimental trauma. Microarrays could be used to produce a comprehensive image of regulated genes at a specific time or to allow an unbiased search for relevant events.
List of papers:
I. Holmin S, von Gertten C, Sandberg-Nordqvist AC, Lendahl U, Mathiesen T (2001). Induction of astrocytic nestin expression by depolarization in rats. Neurosci Lett. 11(1): 151-5.
Pubmed
II. von Gertten C, Holmin S, Mathiesen T, Nordqvist AC. (2003). Increases in matrix metalloproteinase-9 and tissue inhibitor of matrix metalloproteinase-1 mRNA after cerebral contusion and depolarisation. J Neurosci Res. 73(6): 803-10.
Pubmed
III. von Gertten C, Flores Morales A, Holmin S, Mathiesen T, Nordqvist AC (2005). Genomic responses in rat cerebral cortex after traumatic brain injury. BMC Neurosci. 6: 69.
Pubmed
IV. von Gertten C, Lundberg J, Mathiesen T, Flores Morales A, Sandberg Nordqvist A-C (2006). Depolarisation and traumatic brain injury in rat share genomic responses. [Manuscript]
I. Holmin S, von Gertten C, Sandberg-Nordqvist AC, Lendahl U, Mathiesen T (2001). Induction of astrocytic nestin expression by depolarization in rats. Neurosci Lett. 11(1): 151-5.
Pubmed
II. von Gertten C, Holmin S, Mathiesen T, Nordqvist AC. (2003). Increases in matrix metalloproteinase-9 and tissue inhibitor of matrix metalloproteinase-1 mRNA after cerebral contusion and depolarisation. J Neurosci Res. 73(6): 803-10.
Pubmed
III. von Gertten C, Flores Morales A, Holmin S, Mathiesen T, Nordqvist AC (2005). Genomic responses in rat cerebral cortex after traumatic brain injury. BMC Neurosci. 6: 69.
Pubmed
IV. von Gertten C, Lundberg J, Mathiesen T, Flores Morales A, Sandberg Nordqvist A-C (2006). Depolarisation and traumatic brain injury in rat share genomic responses. [Manuscript]
Issue date: 2006-09-01
Rights:
Publication year: 2006
ISBN: 91-7140-859-2
Statistics
Total Visits
Views | |
---|---|
Genomic ...(legacy) | 587 |
Genomic ... | 95 |
Total Visits Per Month
September 2023 | October 2023 | November 2023 | December 2023 | January 2024 | February 2024 | March 2024 | |
---|---|---|---|---|---|---|---|
Genomic ... | 0 | 0 | 0 | 0 | 0 | 1 | 0 |
File Visits
Views | |
---|---|
thesis.pdf(legacy) | 391 |
thesis.pdf | 101 |
thesis.pdf.txt(legacy) | 2 |
Top country views
Views | |
---|---|
United States | 294 |
Sweden | 69 |
China | 52 |
Germany | 46 |
South Korea | 14 |
United Kingdom | 10 |
Russia | 10 |
Denmark | 9 |
Finland | 8 |
Canada | 7 |
Top cities views
Views | |
---|---|
Romeo | 29 |
Sunnyvale | 26 |
Beijing | 20 |
Kiez | 18 |
Stockholm | 16 |
Seoul | 14 |
Ballerup | 7 |
Dublin | 7 |
London | 7 |
Ashburn | 5 |