Biology subjects

Percival, C.

Publications and source records attributed to Percival, C..

3 recordsLinked to original sources

bioRxiv2025

WS6 enables scalable ex vivo expansion and gene editing of epithelial basal stem cells

Modeling human epithelial diseases and developing cell-based therapies require robust methods to expand and manipulate epithelial stem and progenitor cells in vitro. Basal stem/progenitor cells from stratified epithelia can be expanded in 3T3-J2 fibroblast feeder cell co-culture systems, and the addition of the ROCK inhibitor Y-27632 enhances proliferation and culture longevity, a phenomenon described as conditional reprogramming. Here, we present a method incorporating the small molecule WS6 to further improve the proliferation and lifespan of cultured epithelial cells from multiple tissues, including airway, skin, and thymus. Cells maintained in this medium ( EpMED; FAD+Y+WS6) retain basal stem/progenitor cell identity and function, including the capacity to differentiate. We demonstrate their capacity to engraft in vivo in a tracheal transplantation model. In a second application, we generate clonal CRISPR-Cas9 genome edited nasal cultures, introducing targeted knockouts of DNAH5 or DNAI2 to create primary ciliary dyskinesia disease models. We anticipate that our method will have broad applications in epithelial cell biology, disease modeling, and regenerative medicine, while reducing reliance on immortalized or cancer cell lines and animal experimentation.

cell biology↗

bioRxiv2022

Conformational dynamics of cohesin/Scc2 loading complex are regulated by Smc3 acetylation and ATP binding

The ring-shaped cohesin complex is the key player in sister chromatid cohesion, DNA repair, and gene transcription. The loading of cohesin to chromosomes requires the loader Scc2 and is regulated by ATP. This process is also hindered by Smc3 acetylation. However, the molecular mechanism underlying this inhibition remains mysterious. Here we identify a novel configuration of Scc2 with pre-engaged cohesin and reveal dynamic conformations of the cohesin/Scc2 complex in the loading reaction. We demonstrate that Smc3 acetylation blocks the association of Scc2 with pre-engaged cohesin by impairing the interaction of Scc2 with Smc3s head. Lastly, we show that ATP binding induces the cohesin/Scc2 complex to clamp DNA by promoting the interaction between Scc2 and Smc3 coiled coil. Our results illuminate a dynamic reconfiguration of the cohesin/Scc2 complex during loading and indicate how Smc3 acetylation and ATP regulate this process.

biochemistry↗

bioRxiv2021

Brain Networks Detectable by fMRI during On-Line Self Report of Hallucinations in Schizophrenia

An analysis of an internationally shared functional magnetic resonance imaging (fMRI) data involving healthy participants and schizophrenia patients extracted brain networks involved in listening to radio speech and capture hallucination experiences. A multidimensional analysis technique demonstrated that for radio-speech sound files, a brain network matching known auditory perception networks emerged, and importantly, displayed speech-duration-dependent hemodynamic responses (HDRs), confirming fMRI detection of these speech events. In the hallucination-capture data, although a sensorimotor (response) network emerged, it did not show hallucination-duration-dependent HDRs. We conclude that although fMRI retrieved the brain network involved in generating the motor responses indicating the start and end of an experienced hallucination, the hallucination event itself was not detected. Previous reports on brain networks detected by fMRI during hallucination capture is reviewed in this context.

neuroscience↗