%0 Journal Article %A König, Hans-Georg %A Rehm, Markus %A Gudorf, Daniel %A Krajewski, Stan %A Gross, Atan %A Ward, Manus W. %A Prehn, Jochen HM %D 2019 %T Full length Bid is sufficient to induce apoptosis of cultured rat hippocampal neurons. %U https://repository.rcsi.com/articles/journal_contribution/Full_length_Bid_is_sufficient_to_induce_apoptosis_of_cultured_rat_hippocampal_neurons_/10791095 %2 https://repository.rcsi.com/ndownloader/files/19303520 %K Animals %K Newborn %K Apoptosis %K BH3 Interacting Domain Death Agonist Protein %K Caspase 8 %K Cells %K Cultured %K Hippocampus %K Mutant Proteins %K Neurons %K Neurotoxins %K Peptide Hydrolases %K Protein Transport %K Rats %K Inbred F344 %K Receptors %K Glutamate %K Physiology %K Medical Physics %X

BACKGROUND: Bcl-2 homology domain (BH) 3-only proteins are pro-apoptotic proteins of the Bcl-2 family that couple stress signals to the mitochondrial cell death pathways. The BH3-only protein Bid can be activated in response to death receptor activation via caspase 8-mediated cleavage into a truncated protein (tBid), which subsequently translocates to mitochondria and induces the release of cytochrome-C. Using a single-cell imaging approach of Bid cleavage and translocation during apoptosis, we have recently demonstrated that, in contrast to death receptor-induced apoptosis, caspase-independent excitotoxic apoptosis involves a translocation of full length Bid (FL-Bid) from the cytosol to mitochondria. We induced a delayed excitotoxic cell death in cultured rat hippocampal neurons by a 5-min exposure to the glutamate receptor agonist N-methyl-D-aspartate (NMDA; 300 microM).

RESULTS: Western blot experiments confirmed a translocation of FL-Bid to the mitochondria during excitotoxic apoptosis that was associated with the release of cytochrome-C from mitochondria. These results were confirmed by immunofluorescence analysis of Bid translocation during excitotoxic cell death using an antibody raised against the amino acids 1-58 of mouse Bid that is not able to detect tBid. Finally, inducible overexpression of FL-Bid or a Bid mutant that can not be cleaved by caspase-8 was sufficient to induce apoptosis in the hippocampal neuron cultures.

CONCLUSION: Our data suggest that translocation of FL-Bid is sufficient for the activation of mitochondrial cell death pathways in response to glutamate receptor overactivation.

%I Royal College of Surgeons in Ireland