[Age-dependent peculiarities of apoptotic marker proteins expression in the neuroendocrine system of Her2/neu transgenic mice].

The aim of our work was to study the expression of apoptotic signaling proteins and its relation to apoptosis level in neuroendocrine system of HER2/neu transgenic mice in aging. SHR mice served as controls. Bcl-2, Mcl-1, p53 and caspase-8 were demonstrated by immunohistochemistry in supraoptic (SON) and paraventricular (PVN) hypothalamic nuclei and relative content of apoptotic neurosecretory cells was determined. It was demonstrated that apoptosis regulation in different nuclei in old SHR mice was mediated by various signaling pathways: in SON, p53-independent cascade was activated, while in PVN it was p53-dependent. Overexpression of HER2/neu was shown to protect against the age-related apoptosis activation in neurosecretory centers. HER2/neu suppressed the synthesis of proapoptotic protein p53, causing the reduction of caspase-8 expression, that resulted in the increased survival of neurosecretory cells in aging.