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Wade, P.

Publications and source records attributed to Wade, P..

5 recordsLinked to original sources

Methionine Deprivation-induced Reprogramming of Hepatic Rhythms Is Mediated by Glucocorticoid Receptor

The circadian clock tightly interacts with cellular metabolism, and nutritional challenges can profoundly remodel its function. Dietary methionine restriction has been shown to improve metabolic health and extend lifespan. However, whether and how dietary methionine restriction impacts the circadian clock is unclear. Here, we demonstrate that methionine deprivation (MD) in the mouse induces alterations in multiple signaling systems, inducing rhythmic biological events in liver that are entrained by feeding time rather than day/light cycles. Alteration in growth factor signaling leads to loss of activation of a pioneer transcription factor, STAT5, which normally directs rhythmic chromatin localization of the glucocorticoid receptor (GR). Loss of active STAT5 leads to reprogramming of the epigenome and of the GR-directed transcriptome in a manner abolished by liver-specific deletion of GR. These results demonstrate that dietary methionine restriction remodels the circadian biological program directed by glucocorticoid receptor.

genomics↗

Tackling Anticancer Drug Resistance and Endosomal Escape in Aggressive Brain Tumors Using Bioelectronics

Chemotherapy resistance and endosomal entrapment, controlled by intracellular trafficking processes, are major factor in treatment failure. Here, we test the hypothesis that external electrical stimulus can be used to modulate intracellular trafficking of chemotherapeutic drugs in most common malignant brain tumors in childhood (medulloblastoma) and gold nanoparticles (GNPs) in adulthood (glioblastoma). We demonstrate that application of alternating current (AC) with frequencies ranging from KHz-MHz and low strength (1 V/cm) lead to killing of cisplatin and vincristine resistant (mediated by extracellular vesicles) medulloblastoma cell lines. On the other hand, in primary glioblastoma cells high frequency AC (MHz) regulated the endosomal escape of GNPs. No significant effect on the viability of the control medulloblastoma cells (resistant cells cultured in drug free media and non-resistant cells) and glioblastoma cells after AC treatment confirmed targeting of intracellular trafficking process. This work supports future application of AC in drug delivery and brain cancer therapy.

pharmacology and toxicology↗

CUT&Tag-BS: an efficient and low-cost method for simultaneous profiling of histone modification and DNA methylation

It remains a challenge to decipher the complex relationship between DNA methylation, histone modification, and the underlying DNA sequence with limited input material. Here, we developed an efficient, low-input, and low-cost method for simultaneous profiling of genomic localization of histone modification and methylation status of the underlying DNA at single-base resolution from the same cells in a single experiment by integrating CUT&Tag with tagmentation-based bisulfite sequencing (CUT&Tag-BS). We demonstrated the validity of our method for both active and repressive histone modifications using 250,000 mouse ESCs. CUT&Tag-BS shows similar enrichment patterns of histone modification to those observed in non-bisulfite-treated control; it further reveals that H3K4me1-marked regions are mostly CpG-poor, lack methylation concordance, and exhibit prevalent DNA methylation heterogeneity among the cells. We anticipate that CUT&Tag-BS will be widely applied to directly address the genomic relationship between DNA methylation and histone modification, especially in low-input scenarios with precious biological samples.

genomics↗

Killer whale genomes reveal a complex history of recurrent admixture and vicariance

Reconstruction of the demographic and evolutionary history of populations assuming a consensus tree-like relationship can mask more complex scenarios, which are prevalent in nature. An emerging genomic toolset, which has been most comprehensively harnessed in the reconstruction of human evolutionary history, enables molecular ecologists to elucidate complex population histories. Killer whales have limited extrinsic barriers to dispersal and have radiated globally, and are therefore a good candidate model for the application of such tools. Here, we analyse a global dataset of killer whale genomes in a rare attempt to elucidate global population structure in a non-human species. We identify a pattern of genetic homogenisation at lower latitudes and the greatest differentiation at high latitudes, even between currently sympatric lineages. The processes underlying the major axis of structure include high drift at the edge of species range, likely associated with founder effects and allelic surfing during post-glacial range expansion. Divergence between Antarctic and non-Antarctic lineages is further driven by ancestry segments with up to four-fold older coalescence time than the genome-wide average; relicts of a previous vicariance during an earlier glacial cycle. Our study further underpins that episodic gene flow is ubiquitous in natural populations, and can occur across great distances and after substantial periods of isolation between populations. Thus, understanding the evolutionary history of a species requires comprehensive geographic sampling and genome-wide data to sample the variation in ancestry within individuals.

evolutionary biology↗

Characterising the microbiome from host shotgun sequencing data: bacterial and diatom community dynamics derived from killer whale skin

Recent exploration into the interactions and relationship between hosts and their microbiota has revealed a connection between many aspects of the hosts biology, health and associated microorganisms. Whereas amplicon sequencing has traditionally been used to characterise the microbiome, the increasing number of published population genomics datasets offer an underexploited opportunity to study microbial profiles from the host shotgun sequencing data. Here, we use sequence data originally generated from killer whale Orcinus orca skin biopsies for population genomics, to characterise the skin microbiome and investigate how host social and geographic factors influence the microbial community composition. Having identified 845 microbial taxa from 2.4 million reads that did not map to the killer whale reference genome, we found that both ecotypic and geographic factors influence community composition of killer whale skin microbiomes. Furthermore, we uncovered key taxa that drive the microbiome community composition and showed that they are embedded in unique networks, one of which is tentatively linked to diatom presence and poor skin condition. Community composition differed between Antarctic killer whales with and without diatom coverage, suggesting that the previously reported episodic migrations of Antarctic killer whales to warmer waters associated with skin turnover may control the effects of potentially pathogenic bacteria such as Tenacibaculum dicentrarchi. Our work demonstrates the feasibility of microbiome studies from host shotgun sequencing data and highlights the importance of metagenomics in understanding the relationship between host and microbial ecology.

evolutionary biology↗