(Stroke. 2007;38:1036.)
© 2007 American Heart Association, Inc.
Original Contributions |
From INSERM (J.P.L.-A., B.D.R., C.A., E.M., C.O., D.V.), INSERM-Avenir, Caen Cedex, France, Université de Caen Basse-Normandie, Caen Cedex, France, and GIP Cyceron, Caen, France; PAION Deutschland GmbH (K.-U.P.), Aachen, Germany; Laboratoire de Physiopathologie de la Barrière Hémato-Encéphalique (V.B., R.C.), Université dArtois, Faculté des sciences Jean Perrin, France.
Correspondence to Denis Vivien or José P. López-Atalaya, INSERM-Avenir, GIP Cyceron, Bd H.Becquerel, BP 5229, 14074 Caen, France. E-mail vivien{at}cyceron.fr or jose.lopez@umh.es
Background and Purpose Desmoteplase, a recombinant form of the plasminogen activator DSPA
1 from Desmodus rotundus, may offer improved clinical benefits for acute ischemic stroke treatment over the current therapy, recombinant tissue plasminogen activator (rtPA). Accumulating evidence suggests that clinical use of rtPA could be limited by unfavorable properties, including its ability to cross the bloodbrain barrier (BBB), thus potentially adding to the pro-excitotoxic effect of endogenous tPA in cerebral parenchyma. Here, to investigate whether desmoteplase may display a safer profile than the structurally-related tPA, both agents were compared for their ability to cross the BBB and promote neurotoxicity.
Methods First, the passage of vascular DSPA and rtPA was investigated in vitro in a model of BBB, subjected or not to oxygen and glucose deprivation. Second, we studied DSPA- and rtPA-mediated effects in an in vivo paradigm of excitotoxic necrosis.
Results The rtPA and desmoteplase cross the intact BBB by LRP-mediated transcytosis. Under conditions of oxygen and glucose deprivation, translocation rates of both compounds increased; however, unlike rtPA, desmoteplase transport remained LRP-dependent. Additionally, neither intracerebral nor intravenous desmoteplase administration enhanced NMDA-induced excitotoxic striatal damage in vivo. Interestingly, intravenous but not intrastriatal coadministration of desmoteplase and rtPA reduced the pro-excitotoxic effect of rtPA.
Conclusions We show that desmoteplase crosses the BBB but does not promote neuronal death. Moreover, intravenous administration of desmoteplase antagonizes the neurotoxicity induced by vascular rtPA. This action may be caused by competition of desmoteplase with rtPA for LRP binding at the BBB, thus effectively blocking rtPA access to the brain parenchyma.
Key Words: bloodbrain barrier desmoteplase excitotoxicity stroke thrombolysis
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