Delayed minocycline inhibits ischemia-activated matrix metalloproteinases 2 and 9 after experimental stroke.
BACKGROUND
Matrix metalloproteinases 2 and 9 (MMP-2 and MMP-9) are increased in the brain after experimental ischemic stroke in rats. These two proteases are involved with the degradation of the basal lamina and loss of stability of the blood brain barrier that occurs after ischemia and that is associated with thrombolytic therapy in ischemic stroke. Minocycline is a lipophilic tetracycline and is neuroprotective in several models of brain injury. Minocycline inhibits inflammation, apoptosis and extracellular matrix degradation. In this study we investigated whether delayed minocycline inhibits brain MMPs activated by ischemia in a model of temporary occlusion in Wistar rats.


RESULTS
Both MMP-2 and MMP-9 were elevated in the ischemic tissue as compared to the contra-lateral hemisphere after 3 hours occlusion and 21 hours survival (p < 0.0001 for MMP-9). Intraperitoneal minocycline at 45 mg/kg concentration twice a day (first dose immediately after the onset of reperfusion) significantly reduced gelatinolytic activity of ischemia-elevated MMP-2 and MMP-9 (p < 0.0003). Treatment also reduced protein concentration of both enzymes (p < 0.038 for MMP-9 and p < 0.018 for MMP-2). In vitro incubation of minocycline in concentrations as low as 0.1 mug/ml with recombinant MMP-2 and MMP-9 impaired enzymatic activity and MMP-9 was more sensitive at lower minocycline concentrations (p < 0.05).


CONCLUSIONS
Minocycline inhibits enzymatic activity of gelatin proteases activated by ischemia after experimental stroke and is likely to be selective for MMP-9 at low doses. Minocycline is a potential new therapeutic agent to acute treatment of ischemic stroke.
Machado
Livia S
LS
Program in Clinical and Experimental Therapeutics, Clinical Pharmacy Department, College of Pharmacy, University of Georgia, Augusta, GA, USA. lmachadogs@students.mcg.edu
Kozak
Anna
A
Ergul
Adviye
A
Hess
David C
DC
Borlongan
Cesario V
CV
Fagan
Susan C
SC
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D001812:Blood-Brain Barrier / Q000187:drug effects / Q000378:metabolism / Q000503:physiopathology; D001921:Brain / Q000187:drug effects* / Q000201:enzymology / Q000503:physiopathology; D002545:Brain Ischemia / Q000188:drug therapy* / Q000201:enzymology / Q000503:physiopathology; D004195:Disease Models, Animal; D004334:Drug Administration Schedule; D004660:Encephalitis / Q000188:drug therapy / Q000378:metabolism / Q000503:physiopathology; D004789:Enzyme Activation / Q000187:drug effects / Q000502:physiology; D004791:Enzyme Inhibitors / Q000008:administration & dosage; D005109:Extracellular Matrix / Q000187:drug effects / Q000378:metabolism; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D061965:Matrix Metalloproteinase Inhibitors; D020782:Matrix Metalloproteinases / Q000378:metabolism; D008911:Minocycline / Q000008:administration & dosage*; D009410:Nerve Degeneration / Q000188:drug therapy / Q000378:metabolism / Q000503:physiopathology; D018696:Neuroprotective Agents / Q000008:administration & dosage; D051381:Rats; D017208:Rats, Wistar; D020521:Stroke / Q000188:drug therapy* / Q000201:enzymology / Q000503:physiopathology; D013997:Time Factors; D016896:Treatment Outcome
D000893:Anti-Inflammatory Agents; D004791:Enzyme Inhibitors; D061965:Matrix Metalloproteinase Inhibitors; D018696:Neuroprotective Agents; D020782:Matrix Metalloproteinases; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9; D008911:Minocycline