Reduction of glutamate-induced excitotoxicity in murine primary neurons involving calpain inhibition

Excessive glutamate secretion leads to excitotoxicity, which has been shown to underlie neurodegenerative disorders. Excitotoxicity is in part exerted by overactivation of calpains, which promote neuronal cell death via induction of limited proteolysis of the cellular proteins p35, regulatory subunit of cyclin-dependent kinase 5, and alpha II-spectrin. We used primary murine neuronal cells in a model of glutamate toxicity. The protease inhibitor alpha(1)-antitrypsin was able to prevent glutamate toxicity as determined by MTT assay and immunofluorescence. Calpain and caspase 3 activity were reduced following alpha(1)-antitrypsin treatment, as assessed by calpain and caspase 3 activity assays. In addition we could observe a modulation of cleavage of the calpain/caspase substrates alpha II-spectrin and p35 in Western blots. In summary, alpha(1)-antitrypsin shows inhibitory effects on excitotoxicity of primary neurons involving the inhibition of calpain activity. The advantage of using alpha(1)-antitrypsin is that the substance is already in clinical use for the treatment of patients with hereditary alpha(1)-antitrypsin deficiency. Further experiments are required in animal models of neurodegenerative disorders to assess the suitability of this substance in patients suffering from Alzheimer's disease or Parkinson's disease. (C) 2015 Elsevier B.V. All rights reserved.