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Delayed inflammatory mRNA and protein expression after spinal cord injury.

Byrnes KR, Washington PM, Knoblach SM, Hoffman E, Faden AI - J Neuroinflammation (2011)

Bottom Line: As p22PHOX and gp91PHOX are components of the NADPH oxidase enzyme, enzymatic activity and its role in SCI were assessed and NADPH oxidase activity was found to be significantly up-regulated through 6 months post-injury.Further, treating rats with the nonspecific, irreversible NADPH oxidase inhibitor diphenylene iodinium (DPI) reduced both lesion volume and expression of chronic gene cluster proteins one month after trauma.These data demonstrate that inflammation-related genes are chronically up-regulated after SCI and may contribute to further tissue loss.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Neuroscience, Georgetown University Medical Center, NW, Washington, DC (20057), USA. kbyrnes@usuhs.mil

ABSTRACT

Background: Spinal cord injury (SCI) induces secondary tissue damage that is associated with inflammation. We have previously demonstrated that inflammation-related gene expression after SCI occurs in two waves - an initial cluster that is acutely and transiently up-regulated within 24 hours, and a more delayed cluster that peaks between 72 hours and 7 days. Here we extend the microarray analysis of these gene clusters up to 6 months post-SCI.

Methods: Adult male rats were subjected to mild, moderate or severe spinal cord contusion injury at T9 using a well-characterized weight-drop model. Tissue from the lesion epicenter was obtained 4 hours, 24 hours, 7 days, 28 days, 3 months or 6 months post-injury and processed for microarray analysis and protein expression.

Results: Anchor gene analysis using C1qB revealed a cluster of genes that showed elevated expression through 6 months post-injury, including galectin-3, p22PHOX, gp91PHOX, CD53 and progranulin. The expression of these genes occurred primarily in microglia/macrophage cells and was confirmed at the protein level using both immunohistochemistry and western blotting. As p22PHOX and gp91PHOX are components of the NADPH oxidase enzyme, enzymatic activity and its role in SCI were assessed and NADPH oxidase activity was found to be significantly up-regulated through 6 months post-injury. Further, treating rats with the nonspecific, irreversible NADPH oxidase inhibitor diphenylene iodinium (DPI) reduced both lesion volume and expression of chronic gene cluster proteins one month after trauma.

Conclusions: These data demonstrate that inflammation-related genes are chronically up-regulated after SCI and may contribute to further tissue loss.

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Related in: MedlinePlus

Demonstration of pathway connections amongst genes of the delayed-expression group. The 'Transcriptional Regulation' algorithm demonstrated a high degree of interconnection and pathway similarities amongst genes of the delayed-expression cluster (identified with blue bubbles and highlighted in boxes). Genes are organized according to compartments, with extracellularly located proteins placed on the left of the figure, and nuclear proteins on the right. Note the multiple connections between genes of the delayed-expression cluster and a few transcription factors, including ETS1 and SP1, as well as common induction pathways, such as IFNγ and TNFα. Green lines indicate positive interactions; red lines indicate negative interactions. Connections of interest, for example between transcription factors and genes of interest and direct interactions, have been highlighted.
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Figure 3: Demonstration of pathway connections amongst genes of the delayed-expression group. The 'Transcriptional Regulation' algorithm demonstrated a high degree of interconnection and pathway similarities amongst genes of the delayed-expression cluster (identified with blue bubbles and highlighted in boxes). Genes are organized according to compartments, with extracellularly located proteins placed on the left of the figure, and nuclear proteins on the right. Note the multiple connections between genes of the delayed-expression cluster and a few transcription factors, including ETS1 and SP1, as well as common induction pathways, such as IFNγ and TNFα. Green lines indicate positive interactions; red lines indicate negative interactions. Connections of interest, for example between transcription factors and genes of interest and direct interactions, have been highlighted.

Mentions: To determine connectivity amongst the delayed expression gene cluster, GeneGo's MetaCore™ software was used to perform a pathway analysis. 'Direct Interaction' algorithm analysis revealed that several genes were directly linked. FCγRIIα was suggested to directly activate galectin-3 (indicated by a dark green arrow in Figure 3). Moving up by one interaction showed that DAP12 and Slp76 were also directly linked to FCγRIIα and galectin-3, through interaction with Zap70, Syk and SHP-1. In addition, CD53 and CD68 were linked through interactions with c-Jun.


Delayed inflammatory mRNA and protein expression after spinal cord injury.

Byrnes KR, Washington PM, Knoblach SM, Hoffman E, Faden AI - J Neuroinflammation (2011)

Demonstration of pathway connections amongst genes of the delayed-expression group. The 'Transcriptional Regulation' algorithm demonstrated a high degree of interconnection and pathway similarities amongst genes of the delayed-expression cluster (identified with blue bubbles and highlighted in boxes). Genes are organized according to compartments, with extracellularly located proteins placed on the left of the figure, and nuclear proteins on the right. Note the multiple connections between genes of the delayed-expression cluster and a few transcription factors, including ETS1 and SP1, as well as common induction pathways, such as IFNγ and TNFα. Green lines indicate positive interactions; red lines indicate negative interactions. Connections of interest, for example between transcription factors and genes of interest and direct interactions, have been highlighted.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3198932&req=5

Figure 3: Demonstration of pathway connections amongst genes of the delayed-expression group. The 'Transcriptional Regulation' algorithm demonstrated a high degree of interconnection and pathway similarities amongst genes of the delayed-expression cluster (identified with blue bubbles and highlighted in boxes). Genes are organized according to compartments, with extracellularly located proteins placed on the left of the figure, and nuclear proteins on the right. Note the multiple connections between genes of the delayed-expression cluster and a few transcription factors, including ETS1 and SP1, as well as common induction pathways, such as IFNγ and TNFα. Green lines indicate positive interactions; red lines indicate negative interactions. Connections of interest, for example between transcription factors and genes of interest and direct interactions, have been highlighted.
Mentions: To determine connectivity amongst the delayed expression gene cluster, GeneGo's MetaCore™ software was used to perform a pathway analysis. 'Direct Interaction' algorithm analysis revealed that several genes were directly linked. FCγRIIα was suggested to directly activate galectin-3 (indicated by a dark green arrow in Figure 3). Moving up by one interaction showed that DAP12 and Slp76 were also directly linked to FCγRIIα and galectin-3, through interaction with Zap70, Syk and SHP-1. In addition, CD53 and CD68 were linked through interactions with c-Jun.

Bottom Line: As p22PHOX and gp91PHOX are components of the NADPH oxidase enzyme, enzymatic activity and its role in SCI were assessed and NADPH oxidase activity was found to be significantly up-regulated through 6 months post-injury.Further, treating rats with the nonspecific, irreversible NADPH oxidase inhibitor diphenylene iodinium (DPI) reduced both lesion volume and expression of chronic gene cluster proteins one month after trauma.These data demonstrate that inflammation-related genes are chronically up-regulated after SCI and may contribute to further tissue loss.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Neuroscience, Georgetown University Medical Center, NW, Washington, DC (20057), USA. kbyrnes@usuhs.mil

ABSTRACT

Background: Spinal cord injury (SCI) induces secondary tissue damage that is associated with inflammation. We have previously demonstrated that inflammation-related gene expression after SCI occurs in two waves - an initial cluster that is acutely and transiently up-regulated within 24 hours, and a more delayed cluster that peaks between 72 hours and 7 days. Here we extend the microarray analysis of these gene clusters up to 6 months post-SCI.

Methods: Adult male rats were subjected to mild, moderate or severe spinal cord contusion injury at T9 using a well-characterized weight-drop model. Tissue from the lesion epicenter was obtained 4 hours, 24 hours, 7 days, 28 days, 3 months or 6 months post-injury and processed for microarray analysis and protein expression.

Results: Anchor gene analysis using C1qB revealed a cluster of genes that showed elevated expression through 6 months post-injury, including galectin-3, p22PHOX, gp91PHOX, CD53 and progranulin. The expression of these genes occurred primarily in microglia/macrophage cells and was confirmed at the protein level using both immunohistochemistry and western blotting. As p22PHOX and gp91PHOX are components of the NADPH oxidase enzyme, enzymatic activity and its role in SCI were assessed and NADPH oxidase activity was found to be significantly up-regulated through 6 months post-injury. Further, treating rats with the nonspecific, irreversible NADPH oxidase inhibitor diphenylene iodinium (DPI) reduced both lesion volume and expression of chronic gene cluster proteins one month after trauma.

Conclusions: These data demonstrate that inflammation-related genes are chronically up-regulated after SCI and may contribute to further tissue loss.

Show MeSH
Related in: MedlinePlus