Senolytic effects of a modified Gingerenone A

Abstract

Senescent cells accumulate with aging and are associated with several age-associated diseases and functional declines. Eliminating senescent cells with senolytics improves aging phenotypes in mouse models and may improve the health of people with chronic diseases. To date, very few senotherapeutic (senolytics and senomorphics) compounds have been identified. In a recent study, we reported that gingerenone A (GinA) has a senolytic effect via mechanisms including the activation of caspase-3 activity and apoptotic cell death. In this study, we investigated whether GinA has senotherapeutic properties in a mouse model of senescence. Moreover, we modified GinA with eicosapentaenoic acid (EPA) esters (GinA-EPA) or docosahexaenoic acid (DHA) esters (GinA-DHA) to generate modified gingerenone A (modGinA) that could enhance GinA effects. We found that both GinA and modGinA induced biochemical and histological changes consistent with anti-inflammatory, senolytic, and senomorphic effects, leading to improved metabolic and mitochondrial functions.

Fig. 1. Synthesis and distribution of modified Gingerenone A (modGinA).

A Synthesis of GinA-DHA esters and Gin-EPA esters. modGinA is an equimolar mixture of these esters. B Circulating levels of gingerenone A (GinA) following oral administration of 10 mg/kg of GinA (n = 4) or 27 mg/kg modGinA (n = 4) to 19 month-old C57BL/6JN mice. Averages with standard error are reported.

Fig. 2. Chronic administration of GinA and modGinA in aged C57BL/6JN mice.

A Study procedures for daily oral administration of GinA (10 mg/kg, n = 12) or modGinA (27 mg/kg, n = 14) or vehicle (high oleic acid sunflower oil, n = 12) in ~80 week old C57BL/6JN mice for 10 weeks. Blood was collected at 9 weeks during treatment and 10 days after termination of treatment, with brain, muscle and liver also collected. Behavioral studies were carried out following termination of treatment over a period of 10 days. B Circulating levels of IL-2, IL-5 and IL-6 during treatment (i) and after treatment (ii). Proteins level significantly different between treatment groups and vehicle are labeled (**p < 0.01; *0.01 < p < 0.05, Dunnetts test). C Total number of metabolites above the limit of detection (orange) in >70% of samples and total number of significant metabolites (blue) identified in serum, muscle, brain and liver using the unadjusted Kruskal–Wallis test. D Circulating levels of CE 22:6, CE 20:5 and choline in serum during treatment (9 weeks). Data were calculated using the unadjusted Kruskal–Wallis test. E Locomotor activity in an open field chamber was unaffected by treatment throughout the full 30 min of testing F Scatter-plot for all the behavioral tests carried out after termination of treatment and within a 10-day window post-treatment.

Fig. 3. In vivo mouse model of doxorubicin-induced senescence.

A Representative p16 immunofluorescent micrographs from lung of mice receiving vehicle (high oleic acid sunflower oil), 10 mg/kg GinA or 27 mg/kg of modGinA daily for 10 days prior to and 20 days after 10 mg/kg doxorubicin i.p. administration. The negative control group did not receive doxorubicin i.p. administration. Immunofluorescence analysis of colocalized signals for TdTomato (red; p-16) and nuclei stained with DAPI (blue). B Scatterplot of relative tdTomato staining over DAPI between groups (vehicle, GinA, modGinA) and different tissues (one-way ANOVA). Log base 10 scale on relative units. Significant differences between groups are indicated by *0.01 <p < 0.05; **0.001 <p < 0.01 (Mann–Whitney U-test).