The topoisomerase inhibitor amonafide enhances defense responses to promote longevity in C. elegans.
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ABSTRACT: Aging is a major risk factor for disease, and developing effective pharmaceutical interventions to improve healthspan and promote longevity has become a high priority for society. One of the molecular pathways that has emerged from research in various model organisms revolves around lowering AKT1 levels. This prompted our in silico drug screen for small molecules capable of mimicking the transcriptional effects of AKT1 knockdown. We found topoisomerase inhibitors as a top candidate longevity-drug class. Evaluating multiple compounds from this class in C. elegans revealed that the topoisomerase inhibitor amonafide has the greatest benefit on healthspan and lifespan. Intriguingly, the longevity effect of amonafide was not solely dependent on DAF-16/FOXO, the canonical pathway for lifespan extension via AKT1 inhibition. We performed RNA-seq on amonafide-treated worms and revealed a more youthful transcriptional signature, along with the activation of diverse molecular and cellular defense pathways. We found the mitochondrial unfolded protein response (UPRmt) regulator afts-1 to be crucial for both improved healthspan and extended lifespan upon amonafide treatment. Moreover, healthspan was partially dependent on the immune response transcription factor zip-2 and the integrated stress response transcription factor atf-4. We further examined the potential of amonafide in age-related disease. Treating a C. elegans model for Parkinson's disease with amonafide improved mobility. In conclusion, we identified amonafide as a novel geroprotector, activating mitochondrial- pathogenic- and xenobiotic-associated defense responses and may serve as a candidate for Parkinson's disease therapy.
Project description:Transcriptome-based drug screening is emerging as a powerful tool to identify geroprotective compounds to intervene in age-related disease. We hypothesized that, by mimicking the transcriptional signature of the highly conserved longevity intervention of FOXO3 (daf-16 in worms) overexpression, we could identify and repurpose compounds with similar downstream effects to increase longevity. Our in silico screen, utilizing the LINCS transcriptome database of genetic and compound interventions, identified several FDA-approved compounds that activate FOXO downstream targets in mammalian cells. These included the neuromuscular blocker atracurium, which also robustly extends both lifespan and healthspan in C. elegans. This longevity is dependent on both daf-16 signaling and inhibition of the neuromuscular acetylcholine receptor. Other neuromuscular blockers tubocurarine and pancuronium caused similar healthspan benefits. Together, these data demonstrate the capacity to mimic genetic lifespan interventions with drugs, and in doing so, reveal that the neuromuscular acetylcholine receptor regulates the highly conserved FOXO/DAF-16 longevity pathway.
Project description:Molecular aging reflects the time-dependent accumulation of cellular damage and loss of essential cellular functions. FOXO transcription factors and their downstream targets play critical roles in the response to aging-associated cellular damage. Here, we identify and characterize a novel FOXO-regulated stress response gene, Oxidative Stress Responsive Serine-rich Protein 1 (OSER1), whose level of expression dramatically influences lifespan in Bombyx mori, Caenorhabditis elegans, and Drosophila. Overexpression of OSER1 also enhances resistance to oxidative stress, starvation, and heat shock, whereas depletion increases susceptibility to these stressors. In humans, common OSER1 genetic variants are associated with longevity. These data show that OSER1 modulates the oxidative stress response and suggest that OSER1 is a potent positive regulator of lifespan and healthspan in multiple species.
Project description:We investigated the hormetic effects of prenatal hyperbaric normoxia exposure on Drosophila healthspan related to molecular defense mechanisms. HN exposure had no disruptive effect on developmental rate or adult body weight. However, lifespan was clearly enhanced, as was resistance to oxidative and heat stress. In addition, levels of reactive oxygen species were significantly decreased and motor performance was increased. Furthermore, to determine the hormetic mechanism underlying these phenotypic and molecular changes, we performed a genome-wide profiling in HN-exposed and control flies. Genes encoding chitin metabolism were highly up-regulated in both sex, which could possibly serve to scavenge free radicals. These results identify prenatal HN exposure as a potential hormetic factor that may improve longevity and healthspan by enhancing defense mechanisms in Drosophila.
Project description:Ribose-5-phosphate isomerase A (RPIA) is a rate-limiting enzyme, which connects oxidative phase to non-oxidative phase and mediates redox homeostasis in pentose phosphate pathway (PPP). Here, we report that spatially and temporally limited knockdown of rpia-1 prolongs lifespan and improves healthspan in C. elegans, reflecting the evolutionarily conserved phenotypes observed in Drosophila. We first confirmed that both ubiquitous (in N2) and pan-neuronal (in TU3401) knockdown of rpia-1 enhance tolerance to oxidative stress, reduce polyglutamine aggregation, and improve the deteriorated body bending rate caused by polyglutamine aggregation. Next, we observed that both rpia-1 knockdown conditions enhance lifespan. In addition, rpia-1 knockdown in glutamatergic or cholinergic neurons was sufficient to increase lifespan. Besides the regulation of healthspan through the elevation of NADPH levels, we also identified novel molecular mechanisms that contribute to the longevity effect. Our results showed that rpia-1 reduction was accompanied by induction of autophagic flux, activation of AMPK, and inhibition of TOR signaling. Importantly, the lifespan extension by rpia-1 knockdown required the activation of autophagy and AMPK pathways, and reduced TOR sig-naling. Moreover, the RNA-seq data from the two longlived rpia-1 knockdown strains supported our experimental findings and reveal potential downstream targets, which may play key roles in this intervention. Together, our data disclose the specific spatial and temporal conditions and the underlying molecular mechanisms of rpia-1 knockdown-mediated longevity in C. elegans. These findings may facilitate the development of translational medicine and the improvement of lon-gevity research.
Project description:Dietary intervention constitutes a feasible approach for modulating metabolism and improving healthspan and lifespan. Methionine restriction (MR) delays the appearance of age-related diseases and increases longevity in normal mice. However, the effect of MR on premature aging remains to be elucidated. Here, we describe that MR extends lifespan in two different mouse models of Hutchinson-Gilford progeria syndrome (HGPS) by reversing the transcriptome alterations in inflammation and DNA-damage response genes present in this condition. Further, MR improves the lipid profile and alters the levels of bile acids, both in wild-type and in progeroid mice. Notably, treatment with the bile acid cholic acid improves healthspan and lifespan in vivo. These results suggest the existence of a metabolic pathway involved in the longevity extension achieved by MR and support the possibility of dietary interventions for treating progeria.
Project description:Flavin-containing monooxygenases (FMOs) are a conserved family of xenobiotic enzymes upregulated in multiple longevity interventions, including nematode and mouse models. Previous work supports that C. elegans fmo-2 promotes longevity, stress resistance, and healthspan by rewiring endogenous metabolism. However, there are five C. elegans FMOs and five mammalian FMOs, and it is not known whether promoting longevity and health benefits is a conserved role of this gene family. Here, we report that expression of C. elegans fmo-4 promotes lifespan extension and paraquat stress resistance downstream of both dietary restriction and inhibition of mTOR. We find that overexpression of fmo-4 in just the hypodermis is sufficient for these benefits, and that this expression significantly modifies the transcriptome. By analyzing changes in gene expression, we find that genes related to calcium signaling are significantly altered downstream of fmo-4 expression. Highlighting the importance of calcium homeostasis in this pathway, fmo-4 overexpressing animals are sensitive to thapsigargin, an ER stressor that inhibits calcium flux from the cytosol to the ER lumen. This calcium/fmo-4 interaction is solidified by data showing that modulating intracellular calcium with either small molecules or genetics can change expression of fmo-4 and/or interact with fmo-4 to affect lifespan and stress resistance. Further analysis supports a pathway where fmo-4 modulates calcium homeostasis downstream of activating transcription factor-6 (atf-6), whose knockdown induces and requires fmo-4 expression. Together, our data identify fmo-4 as a longevity- promoting gene whose actions interact with known longevity pathways and calcium homeostasis.
Project description:Various anti-aging interventions exhibit potential in extending lifespan, yet most of these interventions are inefficacy or even have deleterious effects on healthspan. Ginkgolide B (GB) is a Ginkgo biloba-derived small molecule that reduces aging-related morbidities; however, the effects of GB on healthspan and longevity remain elusive. Here, we report that continuous oral GB administration in mice starting at 20 months extended their lifespan by 20% and reduced tumour incidence. Besides, GB administration significantly improved healthspan evidenced by enhancement in muscle quality, physical performance, grip strength, metabolism, frailty index, systemic inflammation, and senescence. Moreover, GB administration ameliorated aging-related pathologies without any apparent adverse effects. Single-nucleus RNA sequencing (snRNA-seq) revealed that GB improved aging-associated abnormal cell-type composition, intracellular signalling pathways, and cell-cell communication in skeletal muscles. GB also reduced the levels of aging-induced novel Runx1+ type 2B myonuclei, which are associated with apoptotic burden and aging-related signatures. Runx1 derived senescence, as shown by gain- and loss-of-function assays. Together, a new function of GB in extending the healthspan in aging is identified, which contributes to lifespan extension. The senomorphic effects of GB on the multifactorial aging process may provide new prospects for achieving healthy aging and longevity extension.
Project description:Metabolic stress caused by excess nutrients accelerates aging. We recently demonstrated that the newly discovered enzyme glycerol-3-phosphate phosphatase (G3PP; gene Pgp), which operates an evolutionarily conserved glycerol shunt that hydrolyzes glucose-derived glycerol-3-phosphate to glycerol, counters metabolic stress and promotes healthy aging in C. elegans. However, the mechanism whereby G3PP activation extends healthspan and lifespan, particularly under glucotoxicity, remained unknown. Here, we show that the overexpression of the C. elegans G3PP homolog, PGPH-2, decreases fat levels and mimics, in part, the beneficial effects of calorie restriction, particularly in glucotoxicity conditions, without reducing food intake. PGPH-2 overexpression depletes glycogen stores activating AMP-activate protein kinase, which leads to the HLH-30 nuclear translocation and activation of autophagy, promoting healthy aging. Transcriptomics reveal an HLH-30-dependent longevity and catabolic gene expression signature with PGPH-2 overexpression. Thus, G3PP overexpression activates three key longevity factors, AMPK, the TFEB homolog HLH-30, and autophagy, and may be an attractive target for age-related metabolic disorders linked to excess nutrients.
Project description:Vaccinia virus-related kinase (VRK) is an evolutionarily conserved nuclear protein kinase. VRK-1, the single Caenorhabditis elegans VRK ortholog, functions in cell division and germline proliferation. However, the role of VRK-1 in post-mitotic cells and adult lifespan remain unknown. Here, we show that VRK-1 increases organismal longevity by activating the cellular energy sensor, AMP-activated protein kinase (AMPK), via direct phosphorylation. We found that overexpression of vrk-1 in the soma of adult C. elegans increased lifespan, and conversely, inhibition of vrk-1 decreased lifespan. In addition, vrk-1 was required for longevity conferred by mutations that inhibit C. elegans mitochondrial respiration, which requires AMPK. Notably, VRK-1 directly phosphorylated and up-regulated AMPK in both C. elegans and cultured human cells. Thus, our data show that the somatic nuclear kinase, VRK-1, promotes longevity through AMPK activation, and this function appears to be conserved between C. elegans and humans.