[FAS- and TNF-dependent ways participation in apoptosis mechanisms in hypotalumus in physiological and pathological aging.]

ABSTRACT

The cell resistance to apoptosis can be related to the activity of cytokine-dependent signaling. So, the aim of the work is to investigate the mechanisms of cytokine-dependent FAS/TNF-mediated regulation of apoptosis of neurosecretory cells in the physiological and pathological (overexpression of the oncogene HER-2/Neu) aging. HER2/Neu transgenic accelerated aged mice of different ages and wild type FVB/N were examined. The apoptosis level of neurons in hypothalamic sections (supraoptic and paraventricular nuclei) (TUNEL) and expression of caspase-8, CD178 (FASL), FAS, FADD, TRADD (Western blotting) was determined. Participation of the proinflammatory component in the aging process is shown. FAS, adapter proteins associated with the death domain (FADD and TRADD), caspase-8 expression is activated in hypothalamus in FVB/N mice (wild type) during aging, and it correlates with an increase in the apoptosis level. HER-2/Neu expression leads to the extrinsic apoptotic pathway suppression. In this case, the reception of an apoptotic signal (FAS-receptor expression) and its further transmission (expression of FADD and TRADD) is suppressed. However, in young transgenic mice, increased expression of TRADD can activate one of the survival ways - NF-κB, ERK or PI3K-AKT cascade. Thus, the HER-2/Neu tyrosine kinase receptor plays a role in the mechanism of cell resistance to age-dependent apoptosis, and the FAS/TNF-signaling pathway is one of the targets of HER-2/Neu.