Heterocyclic thioureylenes protect from calcium dependent neuronal cell death.
Mol Pharmacol. 2008 Dec 22;
Authors: Humar M, Graetz C, Roesslein M, Goebel U, Geiger KK, Heimrich B, Pannen BH
Calcium-dependent cell death occurs in neurodegenerative diseases and ischemic or traumatic brain injury. We analyzed whether thioureylenes can act in a neuroprotective manner by pharmacological suppression of calcium-dependent pathological pathways. In human neuroblastoma (SK-N-SH) cells, thioureylenes (thiopental, carbimazole) inhibited the calcium-dependent neuronal protein phosphatase (PP)-2B, the activation of the pro-apoptotic transcription factor nuclear factor of activated T-cells (NFAT), BAD-induced initiation of caspase-3, and poly(ADP-ribose)-polymerase cleavage. Caspase-3 independent cell death was attenuated by carbimazole and the protein kinase C (PKC)delta inhibitor rottlerin by a PP-2B independent mechanism. Neuroprotective effects were mediated by the redox-active sulfur of thioureylenes. Furthermore, we observed that the route of calcium mobilization was differentially linked to caspase-dependent or independent cell death and that BAD-dephosphorylation did not necessarily induce intrinsic caspase activation. In addition, a new 30-35 kDa caspase-3 fragment with an unknown function was identified. In organotypic hippocampal slice cultures, thioureylenes inhibited caspase-3 activation or reduced N-methyl-D-aspartate (NMDA) and kainic acid receptor mediated cell death that was independent of caspase-3. Because prolonged inhibition of caspase-3 resulted in caspase-independent cellular damage, different types of cell death must be taken under therapeutic consideration. Here we show that thioureylenes in combination with PKCdelta inhibitors might represent a promising therapeutic approach to attenuate neuronal damage.
PMID: 19103761 [PubMed - as supplied by publisher]