Mechanism of action of the new ethanolamine derivative bis{2-[(2E)-4-hydroxy-4-oxobut-2-enoyloxy]-N,N-diethylethanaminium}butanedioate

The mechanism of neuroprotective action of a new ethanolamine derivative, bis{2-[(2E)-4-hydroxy-4-oxobut-2-enoyloxy]-N,N-diethylethanaminium}butane-dioate (FDES), was studied by means of dendritic spines visualization in a confocal microscope, calcium imaging in postsynaptic dendritic spines, and knockdown of protein expression in primary mice hippocampal cells culture by RNA interference. It was established that a possible mechanism of FDES action is related to the activation of neuronal store-operated calcium entry (nSOCE) into postsynaptic dendritic spines. During knockdown of the TRPC6 channels (the main regulators of hippocampal SOCE), the hippocampal culture FDES did not activate calcium entry into hippocampal neurons, which indicated the specificity of FDES action on nSOCE. On the model of cerebral ischemia, FDES in comparison to reference agents (citicoline and cytoflavin) improved short-term memory of rats in the Barnes maze test (reduced the number of errors by 71%, p = 0.0023) with respect to data received 24 h before the test. In the nanomolar dose range, FDES was found to demonstrate neuroprotective properties in primary hippocampal culture, as manifested in the ability to protect mushroom spines from amyloid synaptotoxicity by 15% (p ≤ 0.0001), which resulted in stabilizing and enhancing synaptic transmission. The obtained results indicate that FDES is of interest for further investigation as a neuroprotective agent.