Publications by authors named "Allison Janocha"

Article Synopsis
  • Asthma is linked to mitochondrial dysfunction, indicated by lower levels of mitochondrial DNA copy number (mtDNA-CN), which may serve as a proxy for mitochondrial health.* -
  • A study using data from the UK Biobank and the Severe Asthma Research Program found that individuals with asthma consistently have lower mtDNA-CN levels compared to those without asthma, across all age groups.* -
  • The research suggests that lower mtDNA-CN is associated with an increased risk of asthma exacerbations and is influenced by genetic factors rather than inflammation.*
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Article Synopsis
  • - The study explores the connection between mitochondrial dysfunction, indicated by mitochondrial DNA copy number (mtDNA-CN), and asthma diagnosis, severity, and exacerbations.
  • - Results show that asthmatics have lower mtDNA-CN compared to non-asthmatics, but severity levels in asthma do not influence mtDNA-CN.
  • - Higher mtDNA-CN is linked to a reduced risk of severe asthma exacerbations, emphasizing the potential importance of mitochondrial function in asthma management.
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Mitochondria are increasingly recognized to play a role in the airway inflammation of asthma. Model systems to study the role of mitochondrial gene expression in bronchial epithelium are lacking. Here, we create custom bronchial epithelial cell lines that are depleted of mitochondrial DNA.

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Introduction: Mitochondria are increasingly recognized to play a role in the airway inflammation of asthma. Model systems to study the role of mitochondrial gene expression in bronchial epithelium are lacking. Here, we create custom bronchial epithelial cell lines derived from primary airway epithelium that are depleted of mitochondrial DNA.

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Pulmonary arterial hypertension (PAH) is characterized by impaired regulation of pulmonary hemodynamics and vascular growth. Alterations of metabolism and bioenergetics are increasingly recognized as universal hallmarks of PAH, as metabolic abnormalities are identified in lungs and hearts of patients, animal models of the disease, and cells derived from lungs of patients. Mitochondria are the primary organelle critically mediating the complex and integrative metabolic pathways in bioenergetics, biosynthetic pathways, and cell signaling.

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Cisplatin chemotherapy is standard care for many cancers but is toxic to the kidneys. How this toxicity occurs is uncertain. In this study, we identified apurinic/apyrimidinic endonuclease 2 (APE2) as a critical molecule upregulated in the proximal tubule cells (PTC) following cisplatin-induced nuclear DNA and mitochondrial DNA damage in cisplatin-treated C57B6J mice.

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Glucocorticoids (GC) are the mainstay treatment option for inflammatory conditions. Despite the broad usage of GC, the mechanisms by which GC exerts its effects remain elusive. Here, utilizing murine autoimmune and allergic inflammation models, we report that Foxp3 regulatory T (Treg) cells are irreplaceable GC target cells in vivo.

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Pulmonary arterial endothelial cells (PAEC) are mechanistically linked to origins of pulmonary arterial hypertension (PAH). Here, global proteomics and phosphoproteomics of PAEC from PAH (n = 4) and healthy lungs (n = 5) were performed using LC-MS/MS to confirm known pathways and identify new areas of investigation in PAH. Among PAH and control cells, 170 proteins and 240 phosphopeptides were differentially expressed; of these, 45 proteins and 18 phosphopeptides were located in the mitochondria.

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Asthma is a chronic inflammatory disease that is known to cause changes in the extracellular matrix, including changes in hyaluronan (HA) deposition. However, little is known about the factors that modulate its deposition or the potential consequences. Asthmatics with high levels of exhaled nitric oxide (NO) are characterized by greater airway reactivity and greater evidence of airway inflammation.

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Article Synopsis
  • The study looked at how a substance called arginine is used in people with asthma compared to healthy people, finding that asthmatics tend to have higher levels of certain proteins related to arginine metabolism.!
  • Researchers tested 52 asthmatics and 51 healthy individuals, measuring their levels of exhaled nitric oxide (FENO), which indicates how much arginine they're metabolizing.!
  • They found that people with high FENO had worse asthma symptoms and were more severely affected compared to those with low FENO or healthy controls, showing that high FENO could be an important sign of asthma severity.!
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  • High-altitude living leads to chronic low oxygen levels (hypoxia), which affects antioxidant activity and oxidative damage, but the long-term effects are not well understood.
  • The study compares antioxidant levels and DNA damage in various populations, including natives from high altitudes and migrants from lower altitudes.
  • Results indicate that long-term residents (like the Amhara and Sherpa) have better antioxidant defenses and lower DNA damage compared to newer residents or upward migrants, suggesting that duration of residence at high altitude plays a crucial role.
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Elevation of hemoglobin concentration, a common adaptive response to high-altitude hypoxia, occurs among Oromo but is dampened among Amhara highlanders of East Africa. We hypothesized that Amhara highlanders offset their smaller hemoglobin response with a vascular response. We tested this by comparing Amhara and Oromo highlanders at 3,700 and 4,000 m to their lowland counterparts at 1,200 and 1,700 m.

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Article Synopsis
  • Researchers found that in people with asthma, there are high levels of certain enzymes that affect how a substance called arginine is used, which can impact inflammation and how cells get energy.
  • They discovered that more of these enzymes in asthma can keep arginine levels steady, which changes how cells work and might help control inflammation linked to asthma.
  • Mice studies showed that when a specific enzyme is missing, the asthma gets worse, revealing that these enzymes play a big role in managing lung inflammation.
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The impairment of vasodilator nitric oxide (NO) production is well accepted as a typical marker of endothelial dysfunction in vascular diseases, including in the pathophysiology of pulmonary arterial hypertension (PAH), but the molecular mechanisms accounting for loss of NO production are unknown. We hypothesized that low NO production by pulmonary arterial endothelial cells in PAH is due to inactivation of NO synthase (eNOS) by aberrant phosphorylation of the protein. To test the hypothesis, we evaluated eNOS levels, dimerization, and phosphorylation in the vascular endothelial cells and lungs of patients with PAH compared with controls.

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Angiogenesis is closely linked to and precedes eosinophilic infiltration in asthma. Eosinophils are recruited into the airway by chemoattractant eotaxins, which are expressed by endothelial cells, smooth muscles cells, epithelial cells, and hematopoietic cells. We hypothesized that bone marrow-derived proangiogenic progenitor cells that contain eotaxins contribute to the initiation of angiogenesis and inflammation in asthma.

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Aging involves progressive loss of cellular function and integrity, presumably caused by accumulated stochastic damage to cells. Alterations in energy metabolism contribute to aging, but how energy metabolism changes with age, how these changes affect aging, and whether they can be modified to modulate aging remain unclear. In locomotory muscle of post-fertile Caenorhabditis elegans, we identified a progressive decrease in cytosolic phosphoenolpyruvate carboxykinase (PEPCK-C), a longevity-associated metabolic enzyme, and a reciprocal increase in glycolytic pyruvate kinase (PK) that were necessary and sufficient to limit lifespan.

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Article Synopsis
  • Scientists found that a part of the cell called mTORC1 is often active in cancer, but drugs called rapalogs don't always work well because cancer cells find ways to survive.
  • In a study of chronic lymphocytic leukemia (CLL), some cancer cells that resisted a drug called fludarabine showed signs of using more energy in ways that were different from regular cells.
  • By blocking the way those resistant cells make essential nutrients needed for their growth, researchers discovered that they could kill those resistant cancer cells without affecting the sensitive ones.
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Background: The early biological impact of short-term mechanical ventilation on healthy lungs is unknown. The authors aimed to characterize the immediate tidal volume (VT)-related changes on lung injury biomarkers in patients with healthy lungs and low risk of pulmonary complications.

Methods: Twenty-eight healthy patients for knee replacement surgery were prospectively randomized to volume-controlled ventilation with VT 6 (VT6) or 10 (VT10) ml/kg predicted body weight.

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Air-liquid interface cell culture is an organotypic model for study of differentiated functional airway epithelium in vitro. Dysregulation of cellular energy metabolism and mitochondrial function have been suggested to contribute to airway diseases. However, there is currently no established method to determine oxygen consumption and glycolysis in airway epithelium in air-liquid interface.

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Objectives: Nebulization is a potential method for delivering therapeutic agents to lung grafts. Recent evidence suggests that nitrite may mitigate ischemia-reperfusion injury via a nitric oxide-dependent pathway.

Methods: Syngeneic orthotopic left lung transplantation was performed in rats after 7 hours of cold ischemia.

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Objective: Pulmonary arterioles respond to hypoxia with constriction that raises vascular resistance and pulmonary artery blood pressure. The response is sustained indefinitely by the chronic hypoxia of high-altitude residence among highlanders of European and Andean descent, but not Tibetans. The objective of this study was to identify the consequences of lifelong hypoxia exposure for the pulmonary vasculature among Amhara high-altitude natives from Ethiopia.

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Severe pulmonary hypertension is irreversible and often fatal. Abnormal proliferation and resistance to apoptosis of endothelial cells (ECs) and hypertrophy of smooth muscle cells in this disease are linked to decreased mitochondria and preferential energy generation by glycolysis. We hypothesized this metabolic shift of pulmonary hypertensive ECs is due to greater hypoxia inducible-factor1alpha (HIF-1alpha) expression caused by low levels of nitric oxide combined with low superoxide dismutase activity.

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The regulation of nitric oxide synthase 2 (NOS2) in airway epithelial cells plays a key role in the innate host response to a wide variety of microbial agents and also participates in the generation of pathologic airway inflammation. Among the important signalling cascades that direct NOS2 gene expression are nuclear factor kappaB (NFkappaB) and interferon-gamma (IFNgamma)/signal transducer and activator of transcription 1 (STAT-1). Previous studies suggest activator protein-1 (AP-1), in particular c-Fos component of AP-1, influences NOS2 expression.

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