Different roles of matrix metalloproteinases-2 and -9 after human ischaemic stroke

Accumulating data suggest that matrix metalloproteinases (MMPs), in particular MMP-2 and MMP-9, are deleterious after acute ischaemic stroke. A beneficial effect of MMPs in the repairing phases of cerebral ischaemia has also been proposed. This study investigated the relationship between MMP-2 and MMP-9 and stroke subtypes, clinical recovery and haemorrhagic transformation (HT). We measured MMP-9 and MMP-2 plasma levels in 29 patients with ischaemic stroke at days one and seven. MMP-2 levels increased only in lacunar strokes, whilst MMP-9 increased only in patients with more severe stroke. Basal MMP-2 levels were higher in patients with stable or recovering symptoms whilst MMP-9 values at day seven were correlated with worse clinical outcome. No differences related to the presence of HT were found. This study sustains a different behaviour of MMPs after ischaemic stroke. MMP-2 seems to be expressed early and related to better outcome, whilst MMP-9 seems to be late and related to more severe stroke.