Estudio de la Caspasa-3 en un modelo experimental de precondicionamiento isquémico neuronal en cultivo

Abstract

In humans, tansitory ischemic attacks (TIAs) are the clinical correlate of cerebral ischemic preconditioning (IPC) leading to transient resistance called ischemic tolerance (IT). The underlying molecular mechanisms are still not fully understood. Recently, the activation of proteases called caspases has been shown to play an important role in apoptotic death associated with ischemia.Here, we study the Caspase-3 on IPC-induced neuroprotection. Primary cortical neurons were exposed to a moderate subtoxic concentration of N-methyl-Daspartate (NMDA; 20?M NMDA; IPC condition) for 2 hours, followed by incubation for further 90 min in normoxic (presence of oxygen and glucose) or ischemic (oxygen and glucose deprivation; OGD). In parallel, control neurons were not stimulated with NMDA. After 4 hours of incubation in culture médium, neuronal apoptosis (Annexin-V-staining) was analyzed by flow cytometry. Further, the activity and expression of active caspase-3 were determined  using Fluorometric assay and Immunoflurescence, respectively.Previously, the results of the lab group showed that IPC prevented apoptosis induced by OGD in neurons. In this work we show that the IPC prevented OGD induced caspase-3 activation. These finding demonstrate the key role of the apoptosis signalling pathway in neuroprotection induced by IPC against a subsequent ischemic insult and poses caspase-3 as an essential target in ischemic tolerance.