Molecular and Computational Biology Section, Department of Biological Sciences, Dornsife College of Letters, Arts, and Sciences, University of Southern California, Los Angeles.
Leonard Davis School of Gerontology, University of Southern California, Los Angeles.
J Gerontol A Biol Sci Med Sci. 2021 Jan 18;76(2):195-204. doi: 10.1093/gerona/glaa164.
Mating and transfer of male sex peptide (SP), or transgenic expression of SP, causes inflammation and decreased life span in female Drosophila. Mifepristone rescues these effects, yielding dramatic increases in life span. Here targeted metabolomics data were integrated with further analysis of extant transcriptomic data. Each of 7 genes positively correlated with life span were expressed in the brain or eye and involved regulation of gene expression and signaling. Genes negatively correlated with life span were preferentially expressed in midgut and involved protein degradation, amino acid metabolism, and immune response. Across all conditions, life span was positively correlated with muscle breakdown product 1/3-methylhistidine and purine breakdown product urate, and negatively correlated with tryptophan breakdown product kynurenic acid, suggesting a SP-induced shift from somatic maintenance/turnover pathways to the costly production of energy and lipids from dietary amino acids. Some limited overlap was observed between genes regulated by mifepristone and genes known to be regulated by ecdysone; however, mifepristone was unable to compete with ecdysone for activation of an ecdysone-responsive transgenic reporter. In contrast, genes regulated by mifepristone were highly enriched for genes regulated by juvenile hormone (JH), and mifepristone rescued the negative effect of JH analog methoprene on life span in adult virgin females. The data indicate that mifepristone increases life span and decreases inflammation in mated females by antagonizing JH signaling downstream of male SP. Finally, mifepristone increased life span of mated, but not unmated, Caenorhabditis elegans, in 2 of 3 trials, suggesting possible evolutionary conservation of mifepristone mechanisms.
雄肽(SP)的交配和转移,或 SP 的转基因表达,导致雌性果蝇发生炎症和寿命缩短。米非司酮挽救了这些影响,导致寿命显著延长。在这里,靶向代谢组学数据与进一步分析现存转录组学数据相结合。与寿命呈正相关的 7 个基因中的每一个都在大脑或眼睛中表达,涉及基因表达和信号的调节。与寿命呈负相关的基因主要在中肠表达,涉及蛋白质降解、氨基酸代谢和免疫反应。在所有条件下,寿命与肌肉分解产物 1/3-甲基组氨酸和嘌呤分解产物尿酸呈正相关,与色氨酸分解产物犬尿氨酸呈负相关,这表明 SP 诱导的从体细胞维持/更新途径向从膳食氨基酸产生能量和脂质的高成本途径的转变。米非司酮调节的基因与已知受蜕皮激素调节的基因之间存在一些有限的重叠;然而,米非司酮无法与蜕皮激素竞争激活蜕皮激素反应性转基因报告基因。相反,米非司酮调节的基因高度富集受保幼激素(JH)调节的基因,米非司酮挽救了 JH 类似物 methoprene 对成年处女雌蝇寿命的负面影响。数据表明,米非司酮通过拮抗雄肽 SP 下游的 JH 信号来增加交配后雌性的寿命并减少炎症。最后,米非司酮增加了交配但未交配的秀丽隐杆线虫的寿命,在 3 次试验中的 2 次中,这表明米非司酮机制可能存在进化保守性。