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Parecoxib is neuroprotective in spontaneously hypertensive rats after transient middle cerebral artery occlusion: a divided treatment response?

Kelsen J, Kjaer K, Chen G, Pedersen M, Røhl L, Frøkiaer J, Nielsen S, Nyengaard JR, Rønn LC - J Neuroinflammation (2006)

Bottom Line: We found a significant reduction in infarct volume in parecoxib treated animals one week after tMCAo (p < 0.03).We found indications of mRNA up-regulation of IL-1beta, IL-6, TNF-alpha and COX-2, whereas COX-1 remained unaffected.IP parecoxib administration during tMCAo was neuroprotective, as evidenced by a large reduction in mean infarct volume and a lower cortical ADC increment.

View Article: PubMed Central - HTML - PubMed

Affiliation: The Water and Salt Research Centre, University of Aarhus, DK-8000 Aarhus C, Denmark. jesper.kelsen@ki.au.dk

ABSTRACT

Background: Anti-inflammatory treatment affects ischemic damage and neurogenesis in rodent models of cerebral ischemia. We investigated the potential benefit of COX-2 inhibition with parecoxib in spontaneously hypertensive rats (SHRs) subjected to transient middle cerebral artery occlusion (tMCAo).

Methods: Sixty-four male SHRs were randomized to 90 min of intraluminal tMCAo or sham surgery. Parecoxib (10 mg/kg) or isotonic saline was administered intraperitoneally (IP) during the procedure, and twice daily thereafter. Nineteen animals were euthanized after 24 hours, and each hemisphere was examined for mRNA expression of pro-inflammatory cytokines and COX enzymes by quantitative RT-PCR. Twenty-three tMCAo animals were studied with diffusion and T2 weighted MRI within the first 24 hours, and ten of the SHRs underwent follow-up MRI six days later. Thirty-three SHRs were given 5-bromo-2'-deoxy-uridine (BrdU) twice daily on Day 4 to 7 after tMCAo. Animals were euthanized on Day 8 and the brains were studied with free-floating immunohistochemistry for activated microglia (ED-1), hippocampal granule cell BrdU incorporation, and neuronal nuclei (NeuN). Infarct volume estimation was done using the 2D nucleator and Cavalieri principle on NeuN-stained coronal brain sections. The total number of BrdU+ cells in the dentate gyrus (DG) of the hippocampus was estimated using the optical fractionator.

Results: We found a significant reduction in infarct volume in parecoxib treated animals one week after tMCAo (p < 0.03). Cortical ADC values in the parecoxib group were markedly less increased on Day 8 (p < 0.01). Interestingly, the parecoxib treated rats were segregated into two subgroups, suggesting a responder vs. non-responder phenomenon. We found indications of mRNA up-regulation of IL-1beta, IL-6, TNF-alpha and COX-2, whereas COX-1 remained unaffected. Hippocampal granule cell BrdU incorporation was not affected by parecoxib treatment. Presence of ED-1+ activated microglia in the hippocampus was related to an increase in BrdU uptake in the DG.

Conclusion: IP parecoxib administration during tMCAo was neuroprotective, as evidenced by a large reduction in mean infarct volume and a lower cortical ADC increment. Increased pro-inflammatory cytokine mRNA levels and hippocampal granule cell BrdU incorporation remained unaffected.

No MeSH data available.


Related in: MedlinePlus

BrdU incorporation in the dentate gyrus of the hippocampus. We estimated in average between four to six thousand BrdU-positive cells in the hippocampal DG (A). We revealed no significant differences between or within the four groups. The mean number of BrdU-positive cells was generally lower in the tMCAo groups than in the sham groups. However, if the DG was affected by ischemia (see Figure 9D to 9I) the BrdU incorporation increased dramatically (black × and red ×). Note that in one animal (marked with red ×) the ischemic injury also affected the contralateral hippocampus. B shows the BrdU incorporation ratio between the right and left hemispheres. The mean ratios for the four groups indicated no difference in the BrdU incorporation between the hemispheres or groups. Black □■: sham + saline; red □■: sham + parecoxib; black ○●: tMCAo + saline; and red ○●: tMCAo + parecoxib. The ischemic or sham (right) hemispheres are represented with filled symbols, whereas the contralateral (left) hemispheres are unfilled. Mean values are indicated with black horizontal bars.
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Figure 8: BrdU incorporation in the dentate gyrus of the hippocampus. We estimated in average between four to six thousand BrdU-positive cells in the hippocampal DG (A). We revealed no significant differences between or within the four groups. The mean number of BrdU-positive cells was generally lower in the tMCAo groups than in the sham groups. However, if the DG was affected by ischemia (see Figure 9D to 9I) the BrdU incorporation increased dramatically (black × and red ×). Note that in one animal (marked with red ×) the ischemic injury also affected the contralateral hippocampus. B shows the BrdU incorporation ratio between the right and left hemispheres. The mean ratios for the four groups indicated no difference in the BrdU incorporation between the hemispheres or groups. Black □■: sham + saline; red □■: sham + parecoxib; black ○●: tMCAo + saline; and red ○●: tMCAo + parecoxib. The ischemic or sham (right) hemispheres are represented with filled symbols, whereas the contralateral (left) hemispheres are unfilled. Mean values are indicated with black horizontal bars.

Mentions: BrdU incorporation in the DG of the hippocampus was unaffected by ischemia or parecoxib treatment as shown in Figure 8A. The hippocampus is usually not affected by ischemia after tMCAo. However, in two animals with large stroke volumes (marked with crosses in Figure 8A), we saw ischemic damage of the DG and infiltration with activated microglia and macrophages (Figure 9D to 9I). We excluded the BrdU counts from these animals in our statistical analyses. However, their impact on the mean BrdU number would not change the stated conclusions.


Parecoxib is neuroprotective in spontaneously hypertensive rats after transient middle cerebral artery occlusion: a divided treatment response?

Kelsen J, Kjaer K, Chen G, Pedersen M, Røhl L, Frøkiaer J, Nielsen S, Nyengaard JR, Rønn LC - J Neuroinflammation (2006)

BrdU incorporation in the dentate gyrus of the hippocampus. We estimated in average between four to six thousand BrdU-positive cells in the hippocampal DG (A). We revealed no significant differences between or within the four groups. The mean number of BrdU-positive cells was generally lower in the tMCAo groups than in the sham groups. However, if the DG was affected by ischemia (see Figure 9D to 9I) the BrdU incorporation increased dramatically (black × and red ×). Note that in one animal (marked with red ×) the ischemic injury also affected the contralateral hippocampus. B shows the BrdU incorporation ratio between the right and left hemispheres. The mean ratios for the four groups indicated no difference in the BrdU incorporation between the hemispheres or groups. Black □■: sham + saline; red □■: sham + parecoxib; black ○●: tMCAo + saline; and red ○●: tMCAo + parecoxib. The ischemic or sham (right) hemispheres are represented with filled symbols, whereas the contralateral (left) hemispheres are unfilled. Mean values are indicated with black horizontal bars.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC1764728&req=5

Figure 8: BrdU incorporation in the dentate gyrus of the hippocampus. We estimated in average between four to six thousand BrdU-positive cells in the hippocampal DG (A). We revealed no significant differences between or within the four groups. The mean number of BrdU-positive cells was generally lower in the tMCAo groups than in the sham groups. However, if the DG was affected by ischemia (see Figure 9D to 9I) the BrdU incorporation increased dramatically (black × and red ×). Note that in one animal (marked with red ×) the ischemic injury also affected the contralateral hippocampus. B shows the BrdU incorporation ratio between the right and left hemispheres. The mean ratios for the four groups indicated no difference in the BrdU incorporation between the hemispheres or groups. Black □■: sham + saline; red □■: sham + parecoxib; black ○●: tMCAo + saline; and red ○●: tMCAo + parecoxib. The ischemic or sham (right) hemispheres are represented with filled symbols, whereas the contralateral (left) hemispheres are unfilled. Mean values are indicated with black horizontal bars.
Mentions: BrdU incorporation in the DG of the hippocampus was unaffected by ischemia or parecoxib treatment as shown in Figure 8A. The hippocampus is usually not affected by ischemia after tMCAo. However, in two animals with large stroke volumes (marked with crosses in Figure 8A), we saw ischemic damage of the DG and infiltration with activated microglia and macrophages (Figure 9D to 9I). We excluded the BrdU counts from these animals in our statistical analyses. However, their impact on the mean BrdU number would not change the stated conclusions.

Bottom Line: We found a significant reduction in infarct volume in parecoxib treated animals one week after tMCAo (p < 0.03).We found indications of mRNA up-regulation of IL-1beta, IL-6, TNF-alpha and COX-2, whereas COX-1 remained unaffected.IP parecoxib administration during tMCAo was neuroprotective, as evidenced by a large reduction in mean infarct volume and a lower cortical ADC increment.

View Article: PubMed Central - HTML - PubMed

Affiliation: The Water and Salt Research Centre, University of Aarhus, DK-8000 Aarhus C, Denmark. jesper.kelsen@ki.au.dk

ABSTRACT

Background: Anti-inflammatory treatment affects ischemic damage and neurogenesis in rodent models of cerebral ischemia. We investigated the potential benefit of COX-2 inhibition with parecoxib in spontaneously hypertensive rats (SHRs) subjected to transient middle cerebral artery occlusion (tMCAo).

Methods: Sixty-four male SHRs were randomized to 90 min of intraluminal tMCAo or sham surgery. Parecoxib (10 mg/kg) or isotonic saline was administered intraperitoneally (IP) during the procedure, and twice daily thereafter. Nineteen animals were euthanized after 24 hours, and each hemisphere was examined for mRNA expression of pro-inflammatory cytokines and COX enzymes by quantitative RT-PCR. Twenty-three tMCAo animals were studied with diffusion and T2 weighted MRI within the first 24 hours, and ten of the SHRs underwent follow-up MRI six days later. Thirty-three SHRs were given 5-bromo-2'-deoxy-uridine (BrdU) twice daily on Day 4 to 7 after tMCAo. Animals were euthanized on Day 8 and the brains were studied with free-floating immunohistochemistry for activated microglia (ED-1), hippocampal granule cell BrdU incorporation, and neuronal nuclei (NeuN). Infarct volume estimation was done using the 2D nucleator and Cavalieri principle on NeuN-stained coronal brain sections. The total number of BrdU+ cells in the dentate gyrus (DG) of the hippocampus was estimated using the optical fractionator.

Results: We found a significant reduction in infarct volume in parecoxib treated animals one week after tMCAo (p < 0.03). Cortical ADC values in the parecoxib group were markedly less increased on Day 8 (p < 0.01). Interestingly, the parecoxib treated rats were segregated into two subgroups, suggesting a responder vs. non-responder phenomenon. We found indications of mRNA up-regulation of IL-1beta, IL-6, TNF-alpha and COX-2, whereas COX-1 remained unaffected. Hippocampal granule cell BrdU incorporation was not affected by parecoxib treatment. Presence of ED-1+ activated microglia in the hippocampus was related to an increase in BrdU uptake in the DG.

Conclusion: IP parecoxib administration during tMCAo was neuroprotective, as evidenced by a large reduction in mean infarct volume and a lower cortical ADC increment. Increased pro-inflammatory cytokine mRNA levels and hippocampal granule cell BrdU incorporation remained unaffected.

No MeSH data available.


Related in: MedlinePlus