sb-3ct-compound and Cerebral-Infarction

Perinatal hypoxic ischemic (HI) brain injury is a leading cause of long-term neurological handicap in newborn babies. Recently, excessive activity of matrix metalloproteinases (MMPs), and in particular MMP-9, has been implicated in the aetiology of HI injuries to the immature brain. Our previous study suggested that MMP-9 may be involved in the development of the delayed injury processes following HI injury to the developing brain. Given this, we therefore propose that MMP-9 may be a useful target for rescue therapies in the injured developing brain. To address this, we chose to use SB-3CT, a highly selective inhibitor that is known to target only MMP-2 and MMP-9, to attenuate the elevated MMP-9 activity seen following HI injury to the developing brain. Twenty-one-day-old postnatal Wistar rats were subjected to unilateral carotid artery occlusion followed by exposure to hypoxia (8% oxygen for 1 h). SB-3CT (50 mg/kg body weight in 25% dimethyl sulphoxide/75% polyethylene glycol) or an equal volume of vehicle or saline diluent was then administered intraperitoneally at 2, 5 and 14 h following the insult. Gelatin zymography revealed that pro-MMP-9 levels were significantly reduced at 6 h following hypoxic ischaemia (p ≤ 0.05). However, our results showed that despite significantly inhibiting brain pro-MMP-9 activity after hypoxic ischaemia, SB-3CT failed to confer significant neuroprotection in postnatal day 21 rats 3 days after an HI insult. Further investigations are warranted using a recently reported selective water-soluble version of SB-3CT or another MMP-9 selective inhibitor to resolve the role of MMP-9 in the aetiology of HI injury in the developing brain.

Topics: Animals; Behavior, Animal; Body Weight; Brain; Cerebral Infarction; Chromatography, High Pressure Liquid; Enzyme Inhibitors; Heterocyclic Compounds, 1-Ring; Hypoxia-Ischemia, Brain; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Nerve Tissue Proteins; Nervous System Diseases; Rats; Rats, Wistar; Sulfones; Tandem Mass Spectrometry

Neuronal cell death occurs during many neurodegenerative disorders and stroke. The aberrant, excessive activity of matrix metalloproteinases (MMPs), especially MMP-9, contributes directly to neuron apoptosis and brain damage (Rosenberg et al., 1996; Asahi et al., 2001; Gu et al., 2002; Horstmann et al., 2003). We determined that MMP-9 degrades the extracellular matrix protein laminin and that this degradation induces neuronal apoptosis in a transient focal cerebral ischemia model in mice. We also determined that the highly specific thiirane gelatinase inhibitor SB-3CT blocks MMP-9 activity, including MMP-9-mediated laminin cleavage, thus rescuing neurons from apoptosis. We conclude that MMP-9 is a highly promising drug target and that SB-3CT derivatives have significant therapeutic potential in stroke patients.

Topics: Animals; Apoptosis; Cerebral Infarction; Collagenases; Drug Administration Schedule; Drug Evaluation, Preclinical; Enzyme Precursors; Heterocyclic Compounds, 1-Ring; Infusion Pumps, Implantable; Ischemic Attack, Transient; Kinetics; Laminin; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Matrix Metalloproteinase Inhibitors; Matrix Metalloproteinases; Matrix Metalloproteinases, Membrane-Associated; Mice; Mice, Inbred C57BL; Neurons; Protease Inhibitors; Reperfusion; Sulfones