Application of real-time polymerase chain reaction to quantitate induced expression of interleukin-1beta mRNA in ischemic brain tolerance.
A short duration of ischemia (i.e., ischemic preconditioning) was shown to result in significant tolerance to subsequent ischemic injury. Since previous reports suggest that interleukin-1beta (IL-1beta) may be involved in both ischemic damage and neuroprotection, the present work examined the expression of IL-1beta mRNA in cortical brain tissue after an established preconditioning (PC) stimulus known to produce significant brain tolerance to focal stroke after 1-7 days. Significant induction of IL-1beta mRNA was observed in the ipsilateral cortex at 6 hr (87+/-9 copies of the mRNA per microgram of brain tissue compared to 16+/-5 copies in sham-operated samples, P < 0.001, n = 4) and 8 hr (46+/-4 copies, P < 0.01, n = 4) after PC by means of real-time Taqman polymerase chain reaction (PCR). The peak expression of IL-1beta mRNA after PC was significantly (P < 0.01) lower than that after permanent occlusion of the middle cerebral artery (MCAO), i.e., 87+/-9 and 546+/-92 copies of RNA per microgram tissue at peak levels for PC and focal stroke, respectively. Immunohistochemistry studies revealed a parallel induction of IL-1beta in the ipsilateral cortex after PC. The maximal expression of IL-1beta was observed during the first week post-PC, showing marked parallelism with the duration of ischemic tolerance. These data suggest that the significant but low levels of IL-1beta induction after PC may contribute to ischemic brain tolerance.
Wang
X
X
Department of Cardiovascular Pharmacology, SmithKline Beecham Pharmaceuticals, King of Prussia, Pennsylvania, USA. Xinkang.wang@dupontpharma.com
Li
X
X
Currie
R W
RW
Willette
R N
RN
Barone
F C
FC
Feuerstein
G Z
GZ
D000818:Animals; D001253:Astrocytes / Q000502:physiology; D002545:Brain Ischemia / Q000235:genetics* / Q000503:physiopathology*; D002540:Cerebral Cortex / Q000098:blood supply / Q000737:chemistry / Q000502:physiology; D017931:DNA Primers; D005455:Fluorescent Antibody Technique; D015870:Gene Expression / Q000235:genetics; D007375:Interleukin-1 / Q000032:analysis / Q000235:genetics*; D019194:Ischemic Preconditioning; D016133:Polymerase Chain Reaction / Q000379:methods*; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D020521:Stroke / Q000235:genetics / Q000503:physiopathology; D019914:Taq Polymerase; D013997:Time Factors
D017931:DNA Primers; D007375:Interleukin-1; D012333:RNA, Messenger; D019914:Taq Polymerase