Biology subjects

Steiner, J. D.

Publications and source records attributed to Steiner, J. D..

3 recordsLinked to original sources

bioRxiv2025

Resilience and restoration from fasting-refeeding mediated by a nutrient-regulated linker histone

Intermittent fasting and fasting-refeeding regimens can slow biological aging across taxa1. Shifts between fed and fasted states activate ancient nutrient-sensing pathways which alter cellular and epigenetic states to promote longevity2-4. Yet how biological age trajectories progress during fasting-refeeding, and how nutrient-sensing pathways reprogram epigenetic state remain largely unknown. Here we observe increases in predicted biological age of Caenorhabditis elegans during prolonged fasting in adult reproductive diapause, followed by extraordinary reduction of biological age during refeeding. We identify hil-1/H1-0 as an evolutionarily conserved nutrient-regulated linker histone which mediates adaptations to fasting and refeeding downstream of FOXO and TFEB transcription factors. In C. elegans and human cell culture, hil-1/H1-0 upregulation during low-nutrient states promotes long-term survival and subsequent refeeding-induced recovery. Restoration of C. elegans after prolonged fasting is improved by enhancing the natural downregulation of hil-1 specifically during refeeding. Our study identifies HIL-1/H1.0 as part of an ancestral epigenetic switch during fasting-refeeding that reprograms metabolic and cellular states underlying resilience and restoration.

genetics↗

bioRxiv2024

Loss of killifish cGAS/STING function attenuates cellular senescence and age-related signatures but does not extend organismal life span

The cGAS/STING pathway is a central innate immune signaling pathway whose chronic activation has been implicated in numerous age-related pathologies, yet its impact on life span itself is unknown. Here we engineered knockouts of this pathway in the killifish Nothobranchius furzeri, and assessed physiology and aging. In vitro, loss of killifish cGAS or STING mitigated DNA damage-induced senescence in cultured fibroblasts. In vivo, cGAS knockout unexpectedly led to low-grade inflammation. It also attenuated changes in gene expression in response to DNA damage in young animals, and age-related changes in the old, suggesting dampening of senescence and aging. Necroscopy indicated that tissue pathology appeared milder overall in both mutants, though some tissues showed enhanced sterile macrophage infiltration. Despite an attenuated aging signature, however, longevity was not significantly different from wild type. Our findings reveal a potential tradeoff, where inhibiting the cGAS/STING pathway alleviates age-related signatures, but increases sterile inflammation, offsetting beneficial effects on lifespan.

developmental biology↗

bioRxiv2021

A systematic analysis of diet-induced nephroprotection reveals overlapping and conserved changes in cysteine catabolism

Caloric Restriction (CR) extends lifespan and augments cellular stress-resistance from yeast to primates, making CR an attractive strategy for organ protection in the clinic. Translation of CR to patients is complex, due to problems regarding adherence, feasibility and safety concerns in frail patients. Novel tailored dietary regimens, which modulate the dietary composition of macro- and micronutrients rather than reducing calorie intake promise similar protective effects and increased translatability. However, a direct head-to-head comparison to identify the most potent approach for organ protection as well as overlapping metabolic consequences has not been performed. We systematically analyzed six dietary preconditioning protocols - fasting mimicking diet (FMD), ketogenic diet (KD), dietary restriction of branched chained amino acids (BCAA), two dietary regimens restricting sulfur-containing amino acids (SR80/100) and CR - in a rodent model of renal ischemia-reperfusion injury (IRI) to quantify diet-induced resilience in kidneys. Of the administered diets, FMD, SR80/100 and CR efficiently protect from kidney damage after IRI. Interestingly, these approaches show overlapping changes in oxidative and hydrogen sulfide (H2S)-dependent cysteine catabolism as a potential common mechanism of organ protection. Importantly, these metabolic changes can be recapitulated in patients preconditioned by a diet limiting sulfur-containing amino acids indicating conserved diet-induced mechanisms of stress-resistance that may ultimately lead to clinical application.

biochemistry↗