Mitochondria-originated redox signalling regulates KLF-1 to promote longevity in Caenorhabditis elegans

Transgenerational inheritance of mitochondrial hormetic oxidative stress mediated by histone H3K4me3 and H3K27me3 modifications

Mitochondrial hormetic oxidative stress (mtHOS) is crucial in physiology and disease; however, its effects on epigenetic inheritance and organism fitness across generations remains elusive. Utilizing the C. elegans as a model, we elucidate that parental exposure to mtHOS not only elicits a lifespan extension in the exposed individuals but also confers this longevity advantage to the progeny through the transgenerational epigenetic inheritance (TEI) mechanism. This transgenerational transmission of lifespan prolongation depends on the activation of the UPRmt and the synergistic action of the transcription factors DAF-16/FOXO and SKN-1/Nrf2. Additionally, the H3K4me3 and H3K27me3 serve as epigenetic mediators, selectively marking and regulating the expression of genes associated with oxidative stress response and longevity determination. Our findings illuminate the mechanisms underlying the implementation and transmission of mtHOS, revealing a sophisticated interplay among oxidative stress response genes and chromatin remodeling that collectively enhances the progeny's adaptive resilience to future challenges.

N. sphaeroides phycocyanin subunit Ns-α and Ns-β improve C. elegans antioxidative capacity via ROS-related regulation

Oxidative stress and damage to macromolecules due to free radicals such as reactive oxygen species (ROS) are commonly considered factors that can impair health. This study investigated the potential antioxidant properties of of two subunit proteins associated with the pigment-protein complex phycocyanin derived from Nostoc sphaeroides (Gexianmi). Bacterial expression vectors were separately constructed to induce the two engineering subunit proteins, Ns-α and Ns-β. These engineering proteins were then examined for their potential to enhance antioxidative capacity in Caenorhabditis elegans. Firstly, a proper concentration of the proteins Ns-α and Ns-β in vitro exhibited 2, 2-azino-bis 3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging activity. Secondly, while there were no other observed effects on the nematodes, those treated with the proteins showed significant improvements in motility and reduced levels of lipofuscin compared to the control group. Furthermore, thirdly, the treated nematodes demonstrated increased resistance to oxidation, as evidenced by the higher survivals under oxidative conditions induced by 5 mM H2O2. Notably, the treated nematodes exhibited decline in endogenous ROS levels, and the redox-related genes, such as SOD-3 and CAT-1, were down-regulated following consumption of the engineering proteins. Taken together, these findings suggest that engineering proteins Ns-α and Ns-β improve the antioxidative capacity of C. elegans by modulating ROS-related regulation, making them potential modulators in responding to oxidative stressors.

Redox regulation in lifespan determination

One of the major challenges that remain in the fields of aging and lifespan determination concerns the precise roles that reactive oxygen species (ROS) play in these processes. ROS, including superoxide and hydrogen peroxide, are constantly generated as byproducts of aerobic metabolism, as well as in response to endogenous and exogenous cues. While ROS accumulation and oxidative damage were long considered to constitute some of the main causes of age-associated decline, more recent studies reveal a signaling role in the aging process. In fact, accumulation of ROS, in a spatiotemporal manner, can trigger beneficial cellular responses that promote longevity and healthy aging. In this review, we discuss the importance of timing and compartmentalization of external and internal ROS perturbations in organismal lifespan and the role of redox regulated pathways.

Mitochondrial stress and aging: Lessons from C. elegans

Aging is accompanied by a progressive decline in mitochondrial function, which in turn contributes to a variety of age-related diseases. Counterintuitively, a growing number of studies have found that disruption of mitochondrial function often leads to increased lifespan. This seemingly contradictory observation has inspired extensive research into genetic pathways underlying the mitochondrial basis of aging, particularly within the model organism Caenorhabditis elegans. The complex and antagonistic roles of mitochondria in the aging process have altered the view of mitochondria, which not only serve as simple bioenergetic factories but also as signaling platforms for the maintenance of cellular homeostasis and organismal health. Here, we review the contributions of C. elegans to our understanding of mitochondrial function in the aging process over the past decades. In addition, we explore how these insights may promote future research of mitochondrial-targeted strategies in higher organisms to potentially slow aging and delay age-related disease progression.

Icariin Improves Stress Resistance and Extends Lifespan in Caenorhabditis elegans through hsf-1 and daf-2-Driven Hormesis

Aging presents an increasingly significant challenge globally, driven by the growing proportion of individuals aged 60 and older. Currently, there is substantial research interest in pro-longevity interventions that target pivotal signaling pathways, aiming not only to extend lifespan but also to enhance healthspan. One particularly promising approach involves inducing a hormetic response through the utilization of natural compounds defined as hormetins. Various studies have introduced the flavonoid icariin as beneficial for age-related diseases such as cardiovascular and neurodegenerative conditions. To validate its potential pro-longevity properties, we employed Caenorhabditis elegans as an experimental platform. The accumulated results suggest that icariin extends the lifespan of C. elegans through modulation of the DAF-2, corresponding to the insulin/IGF-1 signaling pathway in humans. Additionally, we identified increased resistance to heat and oxidative stress, modulation of lipid metabolism, improved late-life healthspan, and an extended lifespan upon icariin treatment. Consequently, a model mechanism of action was provided for icariin that involves the modulation of various players within the stress-response network. Collectively, the obtained data reveal that icariin is a potential hormetic agent with geroprotective properties that merits future developments.

Recent advances in mass spectrometry-based methods to investigate reversible cysteine oxidation

The post-translational modification of cysteine to diverse oxidative states is understood as a critical cellular mechanism to combat oxidative stress. To study the role of cysteine oxidation, cysteine enrichments and subsequent analysis via mass spectrometry are necessary. As such, technologies and methods are rapidly developing for sensitive and efficient enrichments of cysteines to further explore its role in signaling pathways. In this review, we analyze recent developments in methods to miniaturize cysteine enrichments, analyze the underexplored disulfide bound redoxome, and quantify site-specific cysteine oxidation. We predict that further development of these methods will improve cysteine coverage across more diverse organisms than those previously studied and elicit novel roles cysteines play in stress response.