Overexpression of the Dicer family genes influences lifespan and stress resistance in a tissue-, sex-, and stressor-specific manner in Drosophila melanogaster.

Small non-coding RNAs coordinate essential cellular processes, including gene expression regulation, genome stability maintenance, and transposon suppression. These processes determine aging, lifespan, and resistance of cells and organisms to stress. In this work, we conducted a comprehensive study of the geroprotective effects of overexpression of two Dicer family genes (Dcr-1 and Dcr-2, which are responsible for the biogenesis of miRNAs and siRNAs) in different tissues of Drosophila melanogaster (nervous system, fat body, intestine, muscles). Activation of the Dicer genes affected the lifespan in a tissue- and sex-depending manner. Females with Dcr-1 overexpression in the nervous system exhibited a significant and reproducible increase in both median (10.0-13.4%, p < 0.001) and maximum lifespan (10.0-13.4%, p < 0.01). However, in other cases, the effect was insignificant or negative. Additionally, flies with neuronal Dcr-1 activation had increased expression of several longevity genes (Sirt1, bsk, tgo, Gadd45, Xpc, Azot, foxo, Hsf, Tsc1) and significantly increased survival after acute exposure to 700 Gy γ-radiation (40-200%, p < 0.05). But they had reduced resistance to starvation. This indicates a crucial role of the miRNA machinery and the Dicer family in providing protection against genotoxic effects and coordinating metabolic processes.