Transforming growth factor-beta 1 exhibits delayed gene expression following focal cerebral ischemia.
Transforming growth factor-beta 1 (TGF-beta 1) is a pleiotropic peptide growth factor. The expression of TGF-beta 1 mRNA in the focal ischemic cortex of rats was studied by means of Northern hybridization. A moderately low level of constitutively expressed TGF-beta 1 mRNA was detected following sham-surgery or in the contralateral (nonischemic) cortex. A significant increase of TGF-beta 1 mRNA level in the ischemic cortex was observed at 2 days (3.2-fold increase compared to sham-operated animals, p < 0.01, n = 4) following permanent occlusion of the middle cerebral artery (PMCAO). The elevated TGF-beta 1 mRNA expression was plateaued for up to 15 days (3.6-fold increase, p < 0.01) following PMCAO. This temporal profile for TGF-beta 1 mRNA expression in focal stroke was significantly delayed compared to that of TNF-alpha, IL-1 beta and IL-6 mRNA expressions as demonstrated previously which peaked at 12 h and decreased to almost basal levels by 5 days following PMCAO. Interestingly, the TGF-beta 1 mRNA expression profile was remarkably parallel with that of monocyte/macrophage accumulation in the ischemic cortex, as well as with the increased formation of extracellular matrix in the focal ischemic brain. These data suggest that TGF-beta 1 may play a role in anti-inflammatory process and in tissue remodeling following ischemic brain injury.
Wang
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Department of Cardiovascular Pharmacology, SmithKline Beecham Pharmaceuticals, King of Prussia, PA 19406, USA.
Yue
T L
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White
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Barone
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FC
Feuerstein
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GZ
D000704:Analysis of Variance; D000818:Animals; D004195:Disease Models, Animal; D005786:Gene Expression Regulation / Q000502:physiology*; D002546:Ischemic Attack, Transient / Q000378:metabolism*; D008297:Male; D012333:RNA, Messenger / Q000096:biosynthesis*; D051381:Rats; D011918:Rats, Inbred SHR; D016212:Transforming Growth Factor beta / Q000235:genetics*
D012333:RNA, Messenger; D016212:Transforming Growth Factor beta