Publications by authors named "Andrew Halayko"

Article Synopsis
  • Oxylipins, which are lipid mediators derived from fatty acids, play crucial roles in respiratory health, but their profiles in lung structural cells are not fully understood.
  • The study measured 162 oxylipins in airway smooth muscle, lung fibroblasts, and epithelial cells, both at baseline and after exposure to various stimuli.
  • Results showed that airway smooth muscle and lung fibroblasts had similar oxylipin profiles dominated by CYP450 metabolites, while epithelial cells had a unique profile rich in COX-derived oxylipins, with distinct changes noted upon stimulation that could impact respiratory function.
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Semaphorin3E (Sema3E) is a member of axon guidance proteins that have emerged recently as essential regulators of cell migration and proliferation. It binds to PlexinD1 with high affinity and is expressed in different cell types, including immune, cancer, and epithelial cells. Recent work in our lab has revealed a critical immunoregulatory role of Sema3E in experimental allergic asthma; however, its role in chronic obstructive pulmonary disease (COPD) remains unclear.

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Article Synopsis
  • Dendritic cells (DCs) significantly influence allergic asthma, and the absence of Sema3E worsens asthma symptoms in experimental models.
  • This study focuses on PlexinD1 in CD11c+ DCs using a house dust mite model, comparing PlexinD1 knockout mice (CD11cPLXND1 KO) with wild-type controls (PLXND1fl/fl).
  • Results show that CD11cPLXND1 KO mice had increased airway hyperresponsiveness, mucus production, and immune response, indicating that PlexinD1 plays a crucial role in regulating asthma features through DC signaling.
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Oxidative stress is associated with asthma pathobiology. We reported that oxidized phosphatidylcholines (OxPCs) are mediators of oxidative stress and accumulate in the lung in response to allergen challenge. The current study begins to unravel mechanisms for OxPC accumulation in the lung, providing the first insights about how OxPCs underpin allergic airway pathophysiology, and pre-clinical testing of selective neutralization of OxPCs in a murine model of allergic asthma.

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  • Smoking can make asthma and other lung problems worse, and it changes how our DNA works.
  • Scientists studied the lungs of mice to see how smoking changes DNA patterns and compared them to what happens in humans.
  • They found new DNA changes linked to smoking that could affect health issues like lung function and cancer, showing we need to look closely at lungs to understand smoking's effects better.
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Article Synopsis
  • Interstitial pneumonia with autoimmune features (IPAF) shares similarities with connective tissue disease-associated interstitial lung disease (CTD-ILD) but does not fully meet the criteria for a specific connective tissue disease.
  • A study compared the characteristics and survival of IPAF with CTD-ILD and unclassifiable ILD, revealing that IPAF patients are older and have a greater smoking history compared to CTD-ILD, while having worse lung function than unclassifiable ILD.
  • The findings suggest that while patients with IPAF experience worse survival rates compared to CTD-ILD, they have similar mortality to those with unclassifiable ILD, raising questions about whether IPAF should be viewed as a separate category of interstitial lung disease
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Article Synopsis
  • Hypoxemia in fibrotic interstitial lung disease (ILD) signals disease progression and can predict patient mortality.
  • A risk prediction tool was created to identify new-onset exertional and resting hypoxemia using data from ILD registries in Canada, Australia, and the U.S.
  • The model's effectiveness was assessed, showing good performance based on factors like age, body mass index, and specific lung function measures, although the validation cohort showed some issues with calibration for resting hypoxemia.
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Prenatal and early-life exposure to cigarette smoke (CS) has 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.

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Asthma pathobiology includes oxidative stress that modifies cell membranes and extracellular phospholipids. Oxidized phosphatidylcholines (OxPCs) in lung lavage from allergen-challenged human participants correlate with airway hyperresponsiveness and induce bronchial narrowing in murine thin-cut lung slices. OxPCs activate many signaling pathways, but mechanisms for these responses are unclear.

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Thoracic surgeries involving resection of lung tissue pose a risk of severe postoperative pulmonary complications, including acute respiratory distress syndrome (ARDS) and respiratory failure. Lung resections require one-lung ventilation (OLV) and, thus, are at higher risk of ventilator-induced lung injury (VILI) attributable to barotrauma and volutrauma in the one ventilated lung, as well as hypoxemia and reperfusion injury on the operated lung. Further, we also aimed to assess the differences in localized and systemic markers of tissue injury/inflammation in those who developed respiratory failure after lung surgery versus matched controls who did not develop respiratory failure.

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Background: Little is known about generalisability of randomised controlled trials (RCTs) for idiopathic pulmonary fibrosis (IPF). We evaluated eligibility criteria for phase III IPF RCTs to determine their representativeness in clinical registries, and calculated forced vital capacity (FVC) changes according to eligibility criteria.

Methods: Common eligibility criteria used in >60% of IPF RCTs were identified from a literature search and applied to patients with IPF from prospective Australian and Canadian registries.

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Background: Ventilator-induced lung injury (VILI) can occur as a result of mechanical ventilation to two lungs. Thoracic surgery often requires one-lung ventilation (OLV). The potential for VILI is likely higher in OLV.

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Background: The heterodimer interleukin (IL)-17A/F is elevated in the lungs in chronic respiratory disease such as severe asthma, along with the pro-inflammatory cytokine tumor necrosis factor-α (TNF-α). Although IL-17A/F and TNF-α are known to functionally cooperate to exacerbate airway inflammation, proteins altered by their interaction in the lungs are not fully elucidated.

Results: We used Slow Off-rate Modified Aptamer-based proteomic array to identify proteins that are uniquely and/or synergistically enhanced by concurrent stimulation with IL-17A/F and TNF-α in human bronchial epithelial cells (HBEC).

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Biological sex impacts disease prevalence, severity and response to therapy in asthma, however preclinical studies often use only one sex in murine models. Here, we detail sex-related differences in immune responses using a house dust mite (HDM)-challenge model of acute airway inflammation, in adult mice of two different strains (BALB/c and C57BL/6NJ). Female and male mice were challenged (intranasally) with HDM extract (~ 25 μg) for 2 weeks (N = 10 per group).

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Biological sex influences disease severity, prevalence and response to therapy in allergic asthma. However, allergen-mediated sex-specific changes in lung protein biomarkers remain undefined. Here, we report sex-related differences in specific proteins secreted in the lungs of both mice and humans, in response to inhaled allergens.

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Mitochondrial dysfunction has been reported in chronic obstructive pulmonary disease (COPD). Transfer of mitochondria from mesenchymal stem cells to airway smooth muscle cells (ASMCs) can attenuate oxidative stress-induced mitochondrial damage. It is not known whether mitochondrial transfer can occur between structural cells in the lungs or what role this may have in modulating bioenergetics and cellular function in healthy and COPD airways.

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Background And Objective: Inhalational exposures are a known cause of interstitial lung disease (ILD), but little is understood about their prevalence across ILD subtypes and their relationship with pulmonary function and survival.

Methods: Patients with fibrotic ILD were identified from the multicentre Canadian Registry for Pulmonary Fibrosis. Patients completed questionnaires regarding ILD-related occupational and environmental exposures.

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Background: Progressive fibrosing interstitial lung disease (PF-ILD) is characterised by progressive physiological, symptomatic and/or radiographic worsening. The real-world prevalence and characteristics of PF-ILD remain uncertain.

Methods: Patients were enrolled from the Canadian Registry for Pulmonary Fibrosis between 2015 and 2020.

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Interstitial macrophages (IMs) are key regulators of allergic inflammation. We previously showed that the absence of semaphorin 3E (Sema3E) exacerbates asthma features in both acute and chronic asthma models. However, it has not been studied whether Sema3E, via its receptor plexinD1, regulates IM function in allergic asthma.

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Exposure to maternal diabetes is increasingly recognized as a risk factor for chronic respiratory disease in children. It is currently unclear; however, whether maternal diabetes affects the lung health of male and female offspring equally. This study characterizes the sex-specific impact of a murine model of diet-induced gestational diabetes (GDM) on offspring lung function and airway inflammation.

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Increased senescence and expression of profibrotic genes in old lung fibroblasts contribute to disrepair responses. We reported that primary lung fibroblasts from old mice have lower expression and activity of the cystine transporter Slc7a11/xCT than cells from young mice, resulting in changes in both the intracellular and extracellular redox environments. This study examines the hypothesis that low Slc7a11 expression in old lung fibroblasts promotes senescence and profibrotic gene expression.

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