T-PA: Beyond thrombolysis

Benarroch EE. Neurology 2007;69: 799-802.

Author discusses basic science oo t-PA. t-PA is serine protease that cleaves plassminogen into plasmin that digests fibrin. It is widely distributed in CNS and is involved in synaptic regulation, synaptic plasticity and neural injury. Clinically may wish to neutralize the extravascular neurotoxic effects of t-PA. Neuroserpin is a candidate that inhibits the actions of tPA in the CNS.

Mutations of the neuroserpin gene are linked to familial encephalopathy with neuroserpin inclusion bodies (degenerative disease).

t-PA is present in dense core granules in dendritic spines and axon terminals and is released via calcium dependent exocytosis in response to depolarization or activation of NMDA receptors. The gene encoding for t-PA is induced with neuronal activity involving translation of mRNA. It maybe released from injured blood vessels and microglia, suggesting a role for it in neuroplasticity.