Biology subjects

O'Reilly, S.

Publications and source records attributed to O'Reilly, S..

4 recordsLinked to original sources

bioRxiv2022

A novel antiviral formulation inhibits SARS-CoV-2 infection of human bronchial epithelium

A novel proprietary formulation, ViruSAL, has previously been demonstrated to inhibit diverse enveloped viral infections in vitro and in vivo. We evaluated the ability of ViruSAL to inhibit SARS-CoV-2 infectivity, using physiologically relevant models of the human bronchial epithelium, to model early infection of the upper respiratory tract. ViruSAL potently inhibited SARS-CoV-2 infection of human bronchial epithelial cells cultured as an air-liquid interface (ALI) model, in a concentration- and time-dependent manner. Viral infection was completely inhibited when ViruSAL was added to bronchial airway models prior to infection. Importantly, ViruSAL also inhibited viral infection when added to ALI models post-infection. No evidence of in vitro cellular toxicity was detected in ViruSAL treated cells at concentrations that completely abrogated viral infectivity. Moreover, intranasal instillation of ViruSAL to a rat model did not result in any toxicity or pathological changes. Together these findings highlight the potential for ViruSAL as a novel and potent antiviral for use within clinical and prophylactic settings.

pharmacology and toxicology↗

bioRxiv2022

Bile acid-CoA:amino acid N-acyltransferase gene knockout alters early life development, the gut microbiome and reveals unusual bile acid conjugates in mice

Bile acids are steroid detergents in bile that contribute to fat absorption, cell signaling and microbiome interactions in mammals. The final step in their synthesis is amino acid conjugation with either glycine or taurine to a cholic acid or chenodeoxycholic acid backbone in the liver by the enzyme bile acid-CoA:amino acid N-acyltransferase (BAAT). Here, we describe the microbial, chemical, and physiological consequences of BAAT gene deletion in mice. BAAT-/- mice were underweight after weaning but quickly exhibited catch-up growth. At 3-weeks-of-age, KO animals had increased phospholipid excretion and decreased subcutaneous fat pad mass, glycogen staining in hepatocytes and vitamin A stores in the liver, but these phenotypes were less marked in adulthood. Their bile acid (BA) pool was highly altered throughout the 8-weeks of life but was not completely devoid of conjugated BAs. These animals had 27-fold lower amounts of taurine-conjugated BAs than wildtype in their liver, but similar concentrations of glycine-conjugated BAs and higher microbially-conjugated BAs. The BA pool in BAAT-/- was enriched in a variety of unusual bile acids that were putatively sourced from cysteamine conjugation with subsequent oxidation and methylation of the sulfur group to mimic taurine. KO mice also had an altered microbiome, but most strongly in the first 3-weeks, indicating bile acid conjugation is important for proper microbiome development during the postnatal period. Finally, antibiotic treatment increased taurine, glycine, and the unusually conjugated BAs in BAAT-/- animals, indicating the microbiome was not the likely source of the conjugation. Instead, BA conjugation in KO animals was likely derived from the peroxisomal acyltransferases ACNAT1 and ACNAT2, which are duplications of BAAT in the mouse genome, but inactivated in humans. This study demonstrates that BA conjugation is important for early life development in mice and is facilitated by other host or microbial enzymes besides BAAT in a manner that results in molecular mimics of taurine that may rescue pathological phenotypes.

microbiology↗

bioRxiv2022

Newfoundland and Labrador: A mosaic founder population of an Irish and British diaspora from 300 years ago.

The founder population of Newfoundland and Labrador (NL) is a unique genetic resource, in part due to geographic and cultural isolation, where historical records describe a migration of European settlers primarily from Ireland and England to NL in the 18th and 19th centuries. Whilst its historical isolation, and increase prevalence of certain monogenic disorders, have been appreciated, the fine-scale genetic structure and ancestry of the population has not been well described. Understanding the genetic background on which functional, disease causing, genetic variation resides on would aid informed genetic mapping efforts in the Province. Here, we leverage dense genome-wide SNP data on 1,807 NL individuals to reveal fine-scale genetic structure in NL that is clustered around coastal communities and correlated with Christian denomination. We show that the majority of NL European ancestry can be traced back to the south-east and south-west of Ireland and England, respectively. We date a substantial population size bottleneck approximately 10-15 generations ago in NL, associated with increased haplotype sharing and autozygosity. Our results elucidate novel insights into the population history of NL and demonstrate evidence of a population conducive to further genetic studies and biomarker discovery. Significance StatementNewfoundland and Labrador (NL) has been identified as a founder population, though evidence of its magnitude and subsequent isolation is unclear. Here, analysis of 1,807 NL individuals demonstrates population structure associated with geographical isolation in coastal communities and religious denomination (Catholic or Protestant Christian). Further, NL European ancestry primarily descends from settlers from south-east Ireland and south-west England. This history is associated with increased sharing of longer haplotypes in NL, and NL-specific drift in some communities more than others, providing strong evidence of a founder event occurring about 10-15 generations ago. This study elucidates the detailed population structure of NL and shows enrichment for otherwise low frequency functional variants due to genetic drift useful for potential future biomarker discovery studies.

genetics↗

bioRxiv2021

Elevated phosphorylation of EGFR in NSCLC due to mutations in PTPRH

The role of EGFR in lung cancer is well described with numerous activating mutations that result in phosphorylation and tyrosine kinase inhibitors that target EGFR. While the role of the EGFR kinase in non-small cell lung cancer (NSCLC) is appreciated, control of EGFR signaling pathways through dephosphorylation by phosphatases is not as clear. In recent work we identified mutations in Protein Tyrosine Phosphatase Receptor Type H (Ptprh, also known as SAP-1) as being associated with elevated phosphorylation of EGFR in a mouse model of breast cancer. We have examined a series of tumors from this mouse model, revealing conserved V483M Ptprh mutations within the FVB background, but a series of varied mutations in other backgrounds. Despite the varied Ptprh mutations in other background strains, matched primary and metastatic tumors largely shared mutational profiles. Profiling the downstream events of Ptprh mutant tumors revealed AKT activation, suggesting a key target of PTPRH was EGFR tyrosine 1197. Given the role of EGFR in lung cancer, we explored TCGA data which revealed that a subset of PTPRH mutant tumors shared gene expression profiles with EGFR mutant tumors, but that EGFR mutations and PTPRH mutations were mutually exclusive. Generation of a PTPRH knockout NSCLC cell line resulted in Y1197 phosphorylation of EGFR, and a rescue with expression of wild type PTPRH returned EGFR phosphorylation to parental line values while a rescue with a D986A catalytically dead mutant PTPRH did not, demonstrating that PTPRH targets EGFR. As expected with active EGFR, the knockout of PTPRH was associated with increased growth rate. Moreover, a dose response curve illustrated that two human NSCLC lines that had naturally occurring PTPRH mutations responded to EGFR tyrosine kinase inhibition. Injection of one of the NSCLC human lines into mice resulted in tumors, and Osimertinib treatment resulted in a reduction of tumor volume relative to vehicle controls. Consistent with prior literature from breast cancer, PTPRH mutation resulted in nuclear pEGFR as seen in immunohistochemistry, suggesting that there may also be a role for EGFR as a transcriptional co-factor. Other roles for PTPRH were explored through a receptor tyrosine kinase array, noting elevated phosphorylation of FGFR1. Knockout of PTPRH in NSCLC cell lines resulted in elevated phosphorylated FGFR1 relative to controls, indicating that PTPRH has a number of targets that may be aberrantly activated in NSCLC with mutations in PTPRH. Together these data suggest that mutations in PTPRH in NSCLC may result in clinically actionable alterations using existing therapies.

cancer biology↗