Biology subjects

Gill, E.

Publications and source records attributed to Gill, E..

3 recordsLinked to original sources

bioRxiv2026

Amyloid precursor protein. An Achilles heel to exploit in the treatment of prostate cancer

Background: Epidemiological studies have highlighted an inverse association between cancer and Alzheimers disease (AD), but the mechanisms underlying this association are not currently understood. Amyloid precursor protein (APP) and its cleavage may represent one potential mechanism. Its importance has been heavily researched due to it giving rise to the production of amyloid-beta, a pathological hallmark of AD. APP, however, has not been extensively investigated in cancer. Methods: FFPE prostate tumour and adjacent benign tissue immunohistochemically stained for APP, androgen receptor and the insulin-like growth factor-I receptor (IGF1R). Normal prostate PNT2, androgen sensitive LNCaP and androgen insensitive PC3 in vitro were used to assess the effects of androgen, IGF-I and their inhibitors on APP and its cleavage; changes in protein abundance were measured by western blot; interactions between proteins using co-immunoprecipitation and effects on cell proliferation, apoptosis and cell signalling of APP silenced cells using a BrdU proliferation assay, Muse Cell Analyser and by TMT proteomic analysis respectively. Results: Data showed that APP was upregulated in prostate tumour tissue compared to adjacent benign. Furthermore, in cancer cell models, in contrast to normal prostate epithelial cells, it was observed that APP was critical for prostate cancer cell survival by interacting with androgen and IGF-I signalling pathways. Conclusions: Drugs that target APP have already been developed for AD and our data suggests they offer an exciting opportunity for repurposing in the treatment of prostate cancer.

cancer biology↗

bioRxiv2020

Clearance of senescent cells during cardiac ischemia-reperfusion injury improves heart recovery following myocardial infarction

A key component of cardiac ischemia-reperfusion injury (IRI) is the increased generation of reactive oxygen species, leading to enhanced inflammation and tissue dysfunction in patients following intervention for myocardial infarction. In this study we hypothesized that oxidative stress, due to ischemia-reperfusion, induces senescence which contributes to the pathophysiology of cardiac IRI. We demonstrate that IRI induces cellular senescence in both cardiomyocytes and interstitial cell populations and treatment with the senolytic drug navitoclax after ischemia-reperfusion improves left ventricular function, increases myocardial vascularization, and decreases scar size. SWATH-MS based proteomics reveal that biological processes associated with fibrosis and inflammation, that were increased following ischemia-reperfusion, were attenuated upon senescent cell clearance. Furthermore, navitoclax treatment reduced the expression of proinflammatory, profibrotic and anti-angiogenic cytokines, including interferon gamma-induced protein-10, TGF-{beta}3, interleukin-11, interleukin-16 and fractalkine. Our study provides proof-of-concept evidence that cellular senescence contributes to impaired heart function and adverse remodeling following cardiac ischemia-reperfusion. We also establish that post-IRI senescent cells play a considerable role in the inflammatory response. Subsequently, senolytic treatment, at a clinically feasible time point, attenuates multiple components of this response and improves clinically important parameters. Thus, cellular senescence represents a potential novel therapeutic avenue to improve patient outcomes following cardiac ischemia-reperfusion.

cell biology↗

bioRxiv2019

Circadian control of intrinsic heart rate via a sinus node clock and the pacemaker channel

In the human, there is a circadian rhythm in the resting heart rate and it is higher during the day in preparation for physical activity. Conversely, slow heart rhythms (bradyarrhythmias) occur primarily at night. Although the lower heart rate at night is widely assumed to be neural in origin (the result of high vagal tone), the objective of the study was to test whether there is an intrinsic change in heart rate driven by a local circadian clock. In the mouse, there was a circadian rhythm in the heart rate in vivo in the conscious telemetrized animal, but there was also a circadian rhythm in the intrinsic heart rate in denervated preparations: the Langendorff-perfused heart and isolated sinus node. In the sinus node, experiments (qPCR and bioluminescence recordings in mice with a Per1 luciferase reporter) revealed functioning canonical clock genes, e.g. Bmal1 and Per1. We identified a circadian rhythm in the expression of key ion channels, notably the pacemaker channel Hcn4 (mRNA and protein) and the corresponding ionic current (funny current, measured by whole cell patch clamp in isolated sinus node cells). Block of funny current in the isolated sinus node abolished the circadian rhythm in the intrinsic heart rate. Incapacitating the local clock (by cardiac-specific knockout of Bmal1) abolished the normal circadian rhythm of Hcn4, funny current and the intrinsic heart rate. Chromatin immunoprecipitation demonstrated that Hcn4 is a transcriptional target of BMAL1 establishing a pathway by which the local clock can regulate heart rate. In conclusion, there is a circadian rhythm in the intrinsic heart rate as a result of a local circadian clock in the sinus node that drives rhythmic expression of Hcn4. The data reveal a novel regulator of heart rate and mechanistic insight into the occurrence of bradyarrhythmias at night.

physiology↗