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Biology subjects

Giadone, R.

Publications and source records attributed to Giadone, R..

2 recordsLinked to original sources

Disease-associated mutations directionally modulate epigenetic age in iPSC-derived tissues

Reprogramming somatic cells into induced pluripotent stem cells (iPSCs) resets epigenetic age, creating a major challenge for modeling age-associated cellular states and limiting the use of iPSCs in aging research beyond the genetic component. Recent work has shown that healthy organoids can re-accumulate age-associated epigenetic states over extended culture; whether disease-associated genetic states can directionally reshape these trajectories after reprogramming remains unknown. Here, we present a reproducible, in-vitro approach to re-establish epigenetic aging trajectories using iPSC-derived organoid systems, as quantified by multiple epigenetic clock models. We first demonstrate that epigenetic age progressively increases with serial passaging in a lung organoid model (alveolospheres). We then show that disease-associated mutations in multiple models drive additional, cell-intrinsic shifts in epigenetic age, implicating disease state as an independent modulator of epigenetic clocks. Together, these findings reinforce that iPSC-derived organoids recapitulate epigenetic aging trajectories over time, while highlighting disease state as a potent and potentially tractable modulator of epigenetic age in vitro. By enabling more faithful modeling of age-associated cellular states, this approach expands the utility of iPSC-based systems for dissecting the molecular mechanisms that regulate human aging.

genomics↗

Microbiome depletion rejuvenates the aging brain

Aging is associated with cognitive decline and increased vulnerability to neurodegeneration driven by an array of molecular and cellular changes like impaired vascular integrity, demyelination, reduced neurogenesis, and chronic inflammation. Recent studies implicate the gut microbiome as a modulator of brain aging, but the underlying mechanisms remain elusive. Here, we show that depleting the gut microbiome by administering antibiotics to aged mice induces widespread molecular and structural rejuvenation in the brain. Our transcriptomic analyses by single-nucleus RNA sequencing revealed pronounced transcriptional shifts across multiple brain cell types. We confirmed that antibiotic treatment improves vascular density, promotes myelination, enhances neurogenesis, and reduces microglial reactivity. Functionally, microbiome-depleted mice showed improved hippocampal memory performance. Analyses of brain and plasma cytokine levels showed a decrease in several pro-inflammatory factors post-treatment and identified candidate factors, including the chemokine eotaxin-1. Inhibiting eotaxin-1 alone can reverse several aspects of brain aging. Our findings demonstrate that age-associated microbial inflammation contributes to brain aging and that its attenuation can restore youthful features at the molecular, cellular, and functional levels. Targeting the gut microbiome or its circulating mediators may therefore represent a non-invasive approach to promote brain health and cognitive resilience in aging.

neuroscience↗