Expression and histogenesis of matrix metalloproteinase-9 and transfor-ming growth factor-beta 1 in acute cerebral ischemia model of rats / 中国病理生理杂志

ABSTRACT

AIM:To observe the expression and tissue localization of matrix metalloproteinase 9 (MMP-9) and transforming growth factor beta 1 ( TGF-β1 ) in the rat acute cerebral ischemia model.METHODS:Male Wistar rats were used to establish acute cerebral ischemia model by a suturing method.The rats were divided into normal control group, sham group and ischemia 6 h, 12 h, 1 d, 2 d, 6 d and 14 d groups.The rat cerebral cortex and hippocampus of the brain were collected at different time points.The mRNA and protein levels of MMP-9 and TGF-β1 in the brain tissues were detec-ted by real-time PCR and in situ histochemistry staining, respectively.The levels of MMP-9 and TGF-β1 in the plasma were also measured by ELISA.RESULTS:The results of real-time PCR showed that the mRNA levels of MMP-9 began to in-crease 6 h after acute ischemia and reached to a peak 2 d after acute ischemia.Similarly, the mRNA level of TGF-β1 began to rise 12 h after acute ischemia and reached to the highest level 6 d after acute ischemia.Compared with the sham rats, the mRNA levels of MMP-9 and TGF-β1 in the rat brains that collected at ischemic time of 12 h, 1 d, 2 d, 6 d and 14 d were significantly increased.Moreover, results of in situ histochemical staining showed that the expression of MMP-9 was detected at cerebral cortex and hippocampus 1 d after acute cerebral ischemia.Further studies showed that MMP-9 dyeing of the rat cerebral cortex was most obvious 2 d after the acute cerebral ischemia.Similarly, the rat cortex and hippocampus began to express TGF-β1 2 d after acute ischemia and TGF-β1 staining at rat cerebral cortex was most obvious 6 d after the acute cerebral ischemia.In addition, ELISA showed that the increase in MMP-9 and TGF-β1 was detected in the plasma 12 h after ischemia.Compared with the sham rats, the level of these 2 factors significantly upregulated since 1 d after ischemia. CONCLUSION:The brain tissue itself contributes to the upregulation of MMP-9 and TGF-β1 post acute cerebral ischemia, which shed light on the related research in the field.