Antifibrinolytic agents reduce tissue plasminogen activator-mediated neuronal toxicity in vitro.

Published

Journal Article

INTRODUCTION: Serine proteases and their inhibitors play an important role in physiological homeostasis including neuronal activity, hemostasis, and wound healing. Tissue plasminogen activator (tPA) is involved in normal neuronal plasticity and memory formation but can also be neurotoxic. We hypothesized that the serine protease inhibitor aprotinin confers neuronal protection by inhibiting tPA activity. METHODS: Using cultured rat dopaminergic neuroblasts (N27 line), tPA-induced cytotoxicity was quantitated by an MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay and flow cytometry using propidium iodide DNA staining. The anti-apoptotic effects of aprotinin and other protease inhibitors were also evaluated using these systems. RESULTS: Treatment of cultured neuroblasts with tPA (10-20 microg/ml) caused a dose-dependent decrease in cell viability (71.3+/-2.4 at 10 microg/ml down to 52.7+/-2.5% at 20 microg/m tPA, 24-h treatment), which was potentiated in the absence of serum in the culture medium (59.5+/-6.3% at 10 microg/ml down to 47.9+/-4.7% at 20 microg/ml). Aprotinin was effective in ameliorating cell death when administered 30 min before tPA exposure as shown by increased cell viability (91.8+/-0.6% at tPA at 20 microg/ml), but this protection was significantly reduced when aprotinin was administered after tPA. The efficacy of aprotinin as a neuroprotectant was equivalent or superior to other direct tPA antagonist peptides Glu-Gly-Arg-chlormethylketone (EGRck) and Phe-Pro-Arg-chlormethylketone (FPRck) in this setting. CONCLUSION: These data suggest that one of the mechanisms of neuroprotection afforded by aprotinin may be inhibition of tPA-mediated neurotoxicity.

Full Text

Duke Authors

Cited Authors

  • Sun, H-Y; Szlam, F; Levy, JH; Csete, ME; Tanaka, KA

Published Date

  • March 2009

Published In

Volume / Issue

  • 53 / 3

Start / End Page

  • 325 - 331

PubMed ID

  • 19243318

Pubmed Central ID

  • 19243318

Electronic International Standard Serial Number (EISSN)

  • 1399-6576

Digital Object Identifier (DOI)

  • 10.1111/j.1399-6576.2008.01858.x

Language

  • eng

Conference Location

  • England