Expression of matrix metalloproteinase-9 and intercellular adhesion molecule-1 in the perihematomal tissues in human hypertensive intracerebral hemorrhage and its significance

Objective To investigate the relationship between the expression of matrix metalloproteinase-9 (MMP-9) and intercellular adhesion molecule-1 (ICAM-1) in the perihematomal tissues in human hypertensive,intracerebral hemorrhage (ICH) and brain edema formation following ICH.Methods Paraffin-embedded brain tissues of 39 human fatal cases of ICH from the perihematomal tissues,1—3 cm away from the margin of the hemorrhagic lesion,as well as tissues from the corresponding area at the opposite side as controls,were stained with HE and immunohistochemistry staining.The expressions of MMP-9 and ICAM-1 in the pefihematomal tissues were analyzed with the SPSS 11.5 system.Results ①With MMP-9 immunohistochemical staining positive capillaries in the perihematomal tissues were identified at 2 h ((1.2± 0.8)/HP).The number of MMP-9 positive capillaries began to rise at 5—10 h ((4.1±0.8)/HP) reaching the peak at 45—48 h ((10.6±1.4)/HP,P0.05),then gradually dropped at 96—120 h ((5.0± 1.1)/HP) to zero at 360—408 h.The expression of MMP-9 was negative in the countralateral brain tissues of the hemorrhagic focus.②The ICAM-1 positive capillaries and nerve-cells in the perihematomal tissues were identified at 2 h ((2.1±0.3)/HP).The expression of ICAM-1 started to increase significantly at 17— 24 h after ICH((6.0±1.1)/HP),peaked at 72 h ((11.1±0.9)/HP)and dropped gradually at (168— 312) h ((4.1±0.6)/HP,P0.05).Furthermore,there were few positive nerve-cells and capillaries in the countralateral brain tissues of the hemorrhagic focus.③There was a positive correlation between MMP- 9 and ICAM-1.Conclusions The increased expression of MMP-9 and ICAM-1 after ICH is probably correlated with the brain edema formation in the brain tissues around the hemotoma.MMP-9 possibly has a synergetic effect with ICAM-1 on the secondary brain damage after ICH.