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Biology subjects

Golden, C. S.

Publications and source records attributed to Golden, C. S..

3 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↗

Nuclear Histone H3 Post-translational Modification Profiling in Whole Cells using Spectral Flow Cytometry

Histone modifications play essential roles in regulating chromatin accessibility and downstream transcription, serving as critical determinants of cell identity and function. However, the diversity of histone post-translational modifications (PTMs) and their tendency to be studied in isolation limits our understanding of their coordinated roles in shaping cellular states. Conventional flow cytometry methods for histone PTM assessment suffer from low multiplexing capacity and typically require nuclear isolation, resulting in significant sample loss and an incomplete picture of the overall cell state. Here, we present EpiFlow, a spectral flow cytometry protocol designed for multiparametric analysis of histone PTMs within whole cells. By utilizing a 96-well plate format and preserving the cell entirely, EpiFlow improves throughput and efficiency while retaining sample integrity. This method resolves subtle variations in histone PTMs within neural progenitor cells, capturing distinct chromatin states across the cell cycle and correlating them with several markers. Furthermore, we provide an open-access GitHub repository containing detailed protocols and analysis workflows, ensuring reproducibility and accessibility of this approach. EpiFlow offers a robust framework for exploring chromatin dynamics, with broad implications for advancing fundamental research and therapeutic research.

developmental biology↗

Mapping Cellular Response to Destabilized Transthyretin Reveals Cell- and Amyloidogenic Protein-Specific Signatures

In ATTR amyloidosis, transthyretin (TTR) protein is secreted from the liver and deposited as toxic aggregates at downstream target tissues. Despite recent advancements in treatments for ATTR amyloidosis, the mechanisms underlying misfolded TTR-mediated cellular damage remain elusive. In an effort to define early events of TTR-associated stress, we exposed neuronal (SH-SY5Y) and cardiac (AC16) cells to wild-type and destabilized TTR variants (TTRV122I and TTRL55P) and performed transcriptional (RNAseq) and epigenetic (ATACseq) profiling. We subsequently compared TTR-responsive signatures to cells exposed to destabilized antibody light chain protein associated with AL amyloidosis as well as ER stressors (thapsigargin, heat shock). In doing so, we observed overlapping, yet distinct cell type- and amyloidogenic protein-specific signatures, suggesting unique responses to each amyloidogenic variant. Moreover, we identified chromatin level changes in AC16 cells exposed to mutant TTR which resolved upon pre-incubation with kinetic stabilizer tafamidis. Collectively, these data provide insight into the mechanisms underlying amyloid-mediated cellular damage and provide a robust resource representing cellular responses to aggregation-prone proteins and ER stress.

cell biology↗