Biology subjects

Naaz, A.

Publications and source records attributed to Naaz, A..

5 recordsLinked to original sources

bioRxiv2023

Systematic transcriptomics analysis of calorie restriction and rapamycin unveils their synergistic interaction in prolonging cellular lifespan

Aging is a multifaceted biological process marked by the decline in both mitotic and postmitotic cellular function, often central to the development of age-related diseases. In the pursuit of slowing or even reversing the aging process, a prominent strategy of significant interest is calorie restriction (CR), also known as dietary restriction, and the potential influence of a drug called rapamycin (RM). Both CR and RM have demonstrated the capacity to extend healthspan and lifespan across a diverse array of species, including yeast, worms, flies, and mice. Nevertheless, their individual and combined effects on mitotic and postmitotic cells, as well as their comparative analysis, remain areas that demand a thorough investigation. In this study, we employ RNA-sequencing methodologies to comprehensively analyze the impact of CR, RM, and their combination (CR+RM) on gene expression in yeast cells. Our analysis uncovers distinctive, overlapping, and even contrasting patterns of gene regulation, illuminating the unique and shared effects of CR and RM. Most notably, our findings reveal a synergistic effect of CR+RM in extending the lifespan of postmitotic cells, a result validated in both yeast and human cells. This research offers valuable insights into the processes of aging and presents potential strategies for enhancing healthspan and delaying the onset of age-related diseases. These findings have the potential to revolutionize our approach to implementing these interventions under specific conditions and within the context of age-related diseases.

genomics↗

bioRxiv2023

Curcumin extends the lifespan of aging postmitotic cells with mitochondrial dysfunction

Aging is an inevitable biological process intricately linked to age-related diseases, including cardiovascular diseases, neurodegeneration, sarcopenia, and age-related macular degeneration. These ailments are often exacerbated by mitochondrial dysfunction, which plays a pivotal role in postmitotic cells. Curcumin, a natural compound, is explored for its anti-aging potential. This study explores the influence of curcumin on the postmitotic cellular lifespan (PoMiCL) of yeast during chronological aging, examining its potential implications for age-related diseases. Our findings reveal that curcumin significantly extends the lifespan of postmitotic wildtype yeast cells, with maximal effects observed at lower concentrations, displaying a hormetic response. Importantly, curcumin mitigates accelerated aging in cells afflicted by mitochondrial dysfunction. Intriguingly, the hormetic effect is absent under these conditions. Mechanistically, curcumin enhances ATP levels but induces oxidative stress and inhibits TORC1. These findings shed light on curcumins potential as an anti-aging modulator and its relevance to age-related diseases, offering insights into novel therapeutic approaches for healthy aging while highlighting the context-dependent nature of its effects.

genetics↗

bioRxiv2023

Hemin decreases cellular aging and enhances healthspan and lifespan through the AMPK pathway

The quest to understand and manipulate the mechanisms of cellular aging has far-reaching implications for improving human health and longevity. Our comprehensive effort has led to the discovery of the intriguing anti-aging potential of hemin, an FDA-approved drug primarily used for the treatment of acute intermittent porphyria. Leveraging both yeast and human cell models, we investigate the multifaceted effects of hemin on extending cellular lifespan. Intriguingly, the involvement of the AMPK pathway emerges as a pivotal mechanism underlying hemins anti-aging effects. The exploration of hemins impact on cellular functionality further uncovers its influence on mitochondrial processes. Notably, both mitochondrial-dependent and -independent mechanisms are implicated in hemins ability to extend cellular lifespan, with autophagy playing a significant role in the latter. Additionally, a striking synergy between hemin and the TORC1 inhibitor rapamycin is unveiled, underlining the complexity of cellular signaling networks involved in lifespan extension. Translating these findings to human cells, hemin demonstrates an analogous ability to induce mitochondrial biogenesis, reduce proinflammatory cytokine expression, and enhance antioxidant response. The conservation of hemins anti-aging effects across species holds promise for therapeutic applications in addressing age-related diseases and promoting healthier aging.

genetics↗

bioRxiv2023

Uncharacterized yeast gene YBR238C, an effector of TORC1 signaling in a mitochondrial feedback loop, accelerates cellular aging via HAP4- and RMD9-dependent mechanisms

Uncovering the regulators of cellular aging will unravel the complexity of aging biology and identify potential therapeutic interventions to delay the onset and progress of chronic, aging-related diseases. In this work, we systematically compared gene sets involved in regulating the lifespan of Saccharomyces cerevisiae (a powerful model organism to study the cellular aging of humans) and those with expression changes under rapamycin treatment. Among the functionally uncharacterized genes in the overlap set, YBR238C stood out as the only one downregulated by rapamycin and with an increased chronological and replicative lifespan upon deletion. We show that YBR238C and its paralogue RMD9 oppositely affect mitochondria and aging. YBR238C deletion increases the cellular lifespan by enhancing mitochondrial function. Its overexpression accelerates cellular aging via mitochondrial dysfunction. We find that the phenotypic effect of YBR238C is largely explained by HAP4- and RMD9-dependent mechanisms. Further, we find that genetic or chemical-based induction of mitochondrial dysfunction increases TORC1 (Target of Rapamycin Complex 1) activity that, subsequently, accelerates cellular aging. Notably, TORC1 inhibition by rapamycin (or deletion of YBR238C) improves the shortened lifespan under these mitochondrial dysfunction conditions in yeast and human cells. The growth of mutant cells (a proxy of TORC1 activity) with enhanced mitochondrial function is sensitive to rapamycin whereas the growth of defective mitochondrial mutants is largely resistant to rapamycin compared to wild type. Our findings demonstrate a feedback loop between TORC1 and mitochondria (the TORC1-MItochondria-TORC1 (TOMITO) signaling process) that regulates cellular aging processes. Hereby, YBR238C is an effector of TORC1 modulating mitochondrial function.

genetics↗

bioRxiv2022

Methionine uptake via SLC43A2 transporter is essential for regulatory T lymphocyte survival

It is increasingly clear that cell death, survival or growth decisions of T lymphocyte subsets depend on interplay between cytokine-dependent and metabolic processes. What the metabolic requirements of T regulatory cells (Tregs) for their survival are, and how these requirements are satisfied remain to be fully understood. In this study, we identified a necessary requirement of methionine uptake and utilization for Tregs survival upon interleukin 2 (IL-2) deprivation. Activated Tregs have high methionine uptake and consumption to S-adenosyl methionine (SAM) and S-adenosyl homocysteine (SAH). This methionine uptake is essential for Tregs survival, and is regulated by Notch1 activity. Notch1 controls the expression of the solute carrier protein SLC43A2 transporter during IL-2 deprivation. SLC43A2 is necessary for sufficient methionine uptake, and determines Tregs viability upon IL-2 withdrawal. Collectively, we identify a specifically regulated mechanism of methionine import in Tregs that is necessary for the survival of these cells. This highlights the need for methionine availability and metabolism in contextually regulating cell death in an immunosuppressive population of T lymphocytes.

immunology↗