Biology subjects

Pascoe, C. D.

Publications and source records attributed to Pascoe, C. D..

5 recordsLinked to original sources

bioRxiv2026

LL-37 and Citrullinated-LL-37 elicited Transcriptome and Cytokine Profiles in Human Bronchial Epithelial Cells: Citrullination dampens the inflammatory biosignature

The human host defence peptide LL-37 mediates pleiotropic immunomodulatory functions that can be both pro- and anti-inflammatory. Under inflammatory conditions in the lungs, LL-37 is susceptible to the post-translational modification (PTM) citrullination. The impact of this PTM on LL-37's immunomodulatory functions is not fully understood. Therefore, we characterized the transcriptome and cytokine profile in response to LL-37 and citrullinated-LL-37 (citLL-37), in human bronchial epithelial cells (HBEC). Cells were stimulated with either LL-37 or citLL-37 (0.5 M), or a scrambled peptide (sLL-37). RNA after 4 hours (h) was analyzed with NanoString nCounter Host Response Panel, and 96 cytokines were examined (after 24 h) in tissue culture supernatants (Luminex platform). Genes and cytokines with a Log2 fold-change [≥]0.5 with p<0.05 compared to unstimulated cells were considered differentially expressed (DE). These studies revealed overlapping and distinct biosignatures. There were 118 DE genes with LL-37 and 71 with citLL-37, of which magnitude of change was significantly different for 32 genes. 16 out of 17 DE genes altered by both peptides were directly related to inflammation, and these were significantly less (by ~45%) with citLL-37 compared to LL-37. Similarly, inflammatory cytokines enhanced in response to LL-37 were significantly less (by 37-94%) with citLL-37. Overall, our findings indicate that citrullination of LL-37 does not abrogate cellular response in HBEC, instead dampens the inflammatory biosignature induced by LL-37.

immunology↗

bioRxiv2023

Early life exposure to cigarette smoke is associated with lung function changes and primes gene expression and DNA methylation changes at Cyp1a1 upon exposure later in life

Prenatal and early life exposure to cigarette smoke (CS) have repeatedly been shown to induce stable, long-term changes in DNA methylation (DNAm) in offspring. It has been hypothesized that these changes might be functionally related to the known outcomes of prenatal and early life CS exposure, which include impaired lung development, altered lung function and increased risk of asthma and wheeze. However, to date, few studies have examined DNAm changes induced by prenatal CS in tissues of the lung, and even fewer have attempted to examine the specific influences of prenatal versus early postnatal exposures. Here, we have established a mouse model of CS exposure which isolates the effects of prenatal and early postnatal CS exposures in early life. We have used this model to measure the effects of prenatal and/or postnatal CS exposures on lung function and immune cell infiltration as well as DNAm and expression of Cyp1a1, a candidate gene previously observed to demonstrate DNAm differences upon CS exposure in humans. Our study revealed that exposure to CS prenatally and in the early postnatal period cause long-lasting differences in offspring lung function, gene expression and lung Cyp1a1 DNAm, which wane over time but are reestablished upon re-exposure to CS in adulthood. This study creates a testable mouse model which can be used to investigate the effects of prenatal and early postnatal CS exposures and will contribute to the design of intervention strategies to mediate these detrimental effects.

genetics↗

bioRxiv2022

Proteomic Profiling of Hypoplastic Lungs Suggests an Underlying Inflammatory Response in the Pathogenesis of Abnormal Lung Development in Congenital Diaphragmatic Hernia

The pathogenesis of lung hypoplasia in congenital diaphragmatic hernia (CDH), a common birth defect, is poorly understood. The diaphragmatic defect can be repaired surgically, but the abnormal lung development contributes to a high mortality in these patients. To better understand the underlying pathobiology, we used the nitrofen rat model of CDH and characterized the proteome of hypoplastic CDH lungs at the alveolar stage (E21). Amongst the 218 significantly altered proteins between CDH and control lungs were Tenascin C, CREBBP, LYN and STAT3. We showed that Tenascin C was decreased around the distal airway branches in nitrofen and human fetal CDH lungs. In contrast, STAT3 was significantly increased in the airway epithelium of nitrofen lungs at E21. STAT3 inhibition after direct nitrofen exposure to fetal rat lung explants (E14.5) partially reversed the hypoplastic lung phenotype ex vivo by increasing peripheral lung budding. Moreover, we demonstrated that several STAT3 associated cytokines (IL-15, IL-9, IL-2) are increased in fetal tracheal aspirates of CDH survivors compared to non-survivors after fetoscopic tracheal occlusion. Using pathway analysis for significantly altered proteins in our proteomic analysis, we observed an enrichment in inflammatory response associated with Epstein Barr Virus and cytokine signaling in nitrofen CDH lungs. However, we were unable to detect EBV mRNA via in-situ Hybridization in human CDH lungs. With our unbiased proteomics approach, we show for the first time that inflammatory processes are likely underlying the pathogenesis of abnormal lung development in CDH.

developmental biology↗

bioRxiv2020

Integrating Lung Tissue and Lavage Proteomes Reveals Unique Pathways in Allergen-Challenged Mice

To capture interplay between biological pathways we analyzed the proteome from matched lung tissue and bronchoalveolar lavage fluid (BALF) of individual allergen-naive and house dust mite (HDM)-challenged BALB/c mice, a model of allergic asthma. Unbiased label-free LC-MS/MS analysis quantified 2,675 proteins from tissue and BALF of allergen-naive and HDM-exposed mice. In comparing the four datasets we found significantly greater diversity in proteins between lung tissue and BALF than in the changes induced by HDM challenge. The biological pathways enriched after allergen exposure were compartment-dependent. Lung tissue featured innate immune responses and oxidative stress, while BALF most strongly revealed changes in metabolism. We combined lung tissue and BALF proteomes, which principally highlighted oxidation reduction (redox) pathways, a finding influenced chiefly by the lung tissue dataset. Integrating lung and BALF proteomes also uncovered new proteins and biological pathways that may mediate lung tissue and BALF interactions after allergen challenge, for example, B Cell Receptor signaling. We demonstrate that enhanced insight is fostered when different biological compartments from the lung are investigated in parallel. Integration of proteomes from lung tissue and BALF compartments reveals new information about protein networks in the response to environmental challenge and interaction between intracellular and extracellular process.

systems biology↗

bioRxiv2019

Oxidised phosphatidylcholines induce multiple functional defects in airway epithelial cells

Oxidative stress is a hallmark of numerous airway diseases, contributing to extensive cell and tissue damage. Cell membranes and the airway mucosal lining are rich in phospholipids that are particularly susceptible to oxidative attack, producing bioactive molecules including oxidized phosphatidylcholines (OxPC). With the recent discovery of elevated OxPC in asthmatic patients after allergen challenge, we hypothesized that OxPC directly contribute to disease by inducing airway epithelial cell dysfunction. We found that OxPC induced dose-dependent cell stress and loss of viability in BEAS-2B and Calu-3 cell lines and primary human epithelial cells. These responses corresponded with significant epithelial barrier dysfunction, which was further compounded when combining OxPC with an epithelial wound. OxPC inhibited DNA synthesis and migration required to re-establish barrier function, but cells recovered if OxPC were washed off soon after treatment. OxPC induced generation of reactive oxygen species, lipid peroxidation and mitochondrial dysfunction, raising the possibility that OxPC cause pathological lipid metabolism in a self-propagating cycle. The oxidative stress induced by OxPC could not be abrogated by putative OxPC receptor blockers, but partial recovery of barrier function, proliferation and lipid peroxidation could be achieved with the antioxidant n-acetyl cysteine. In summary, we have identified OxPC as a group of bioactive molecules that significantly impair multiple facets of epithelial cell function, consistent with pathological features of asthma. Further characterisation of the mechanisms by which OxPC affect epithelial cells could yield new insights into how oxidative stress contributes to the pathogenesis of airway disease.

cell biology↗