Cortisol as a cerebral cortex neurons apoptosis regulator in acute phase of ischemic stroke (clinical and pathological study)

Abstract

In response to ischemic stroke (IS) a natural activation of the stress-realizing system occurs. The features of this activation influence the outcome of the acute period and the prognosis of recovery and can be adjusted. At the same time, the role of the stress-realizing system in the pathogenesis of IS is still unexplored.Objective: to investigate the effect of peripheral blood cortisol concentration on the regulation of apoptosis of neurons of the cerebral cortex in the acute phase of IS.Material and methods. A prospective clinical and pathological study was performed. It included 9 patients with IS in the left middle cerebral artery territory who were admitted to hospital and died in the hyperacute phase of IS and had no infectious complications, allergic reactions or oncological diseases and who did not undergo thrombolysis. The cerebral cortex was examined. Neuron-specific enolase (NSE), protein 53 (p53), caspase 3, caspase 8, Fas receptor (CD95), and Fas apoptotic inhibitory molecule 2 (FAIM2) were determined on the slices using an indirect immunoperoxidase immunohistochemical staining method. A total of 567 microscopic fields were analysed for the group of patients with IS and 63 fields for the control group (three people). Before death, the blood concentrations of sFas, sFasL, cortisol, adrenocorticotropic hormone, adrenaline and norepinephrine were determined by enzyme immunoassay (the control group consisted of 28 people).Results. Significant correlation was found between the proportion of casp3-positive neurons and the concentration of cortisol in peripheral blood in zones 2 (r=0.263; p<0.01) and 3 (r=0.383; p<0.01). In the 2nd zone, significant negative correlation was found with the concentrations of sFas (r=-0.177; p<0.05) and sFasL (r=-0.164; p<0.05); in the 3rd zone, significant positive correlation was found with the ratio of the concentrations of sFasL and sFas (r=0.240; p<0.01). The proportion of Fas-positive neurons in the cerebral cortex correlated significantly with the concentration of the soluble form of this molecule (for the 1st zone – r=0.222, for the 2nd zone – r=0.438, for the 3rd zone – r=0.289; p<0.01) and the ratio of the concentrations of sFasL and sFas (respectively: r=0.231, r=0.266 and r=0.281; p<0.01) in the peripheral blood.Conclusion. Peripheral blood cortisol concentration is a factor that determines the regulation of apoptosis of neurons in the cerebral cortex in the acute phase of IS.