LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Your last searches

  1. AU="Lajoie, Stephane"
  2. AU=Schrer Orlando D.
  3. AU="El-Refaie, Ahmed Mohamed"
  4. AU="Truax, Jim"

Search results

Result 1 - 10 of total 19

Search options

  1. Article ; Online: Air Pollution Drives Macrophage Senescence through a Phagolysosome-15-Lipoxygenase Pathway.

    Thomas, Sarah A / Yong, Hwan Mee / Rule, Ana M / Gour, Naina / Lajoie, Stephane

    ImmunoHorizons

    2024  Volume 8, Issue 4, Page(s) 307–316

    Abstract: Urban particulate matter (PM; uPM) poses significant health risks, particularly to the respiratory system. Fine particles, such as PM2.5, can penetrate deep into the lungs and exacerbate a range of health problems, including emphysema, asthma, and lung ... ...

    Abstract Urban particulate matter (PM; uPM) poses significant health risks, particularly to the respiratory system. Fine particles, such as PM2.5, can penetrate deep into the lungs and exacerbate a range of health problems, including emphysema, asthma, and lung cancer. PM exposure is also linked to extrapulmonary disorders such as heart and neurodegenerative diseases. Moreover, prolonged exposure to elevated PM levels can reduce overall life expectancy. Senescence is a dysfunctional cell state typically associated with age but can also be precipitated by environmental stressors. This study aimed to determine whether uPM could drive senescence in macrophages, an essential cell type involved in particulate phagocytosis-mediated clearance. Although it is known that uPM exposure impairs immune function, this deficit is multifaceted and incompletely understood, partly because of the use of particulates such as diesel exhaust particles as a surrogate for true uPM. uPM was collected from several locations in the United States, including Baltimore, Houston, and Phoenix. Bone marrow-derived macrophages were stimulated with uPM or reference particulates (e.g., diesel exhaust particles) to assess senescence-related parameters. We report that uPM-exposed bone marrow-derived macrophages adopt a senescent phenotype characterized by increased IL-1α secretion, senescence-associated β-galactosidase activity, and diminished proliferation. Exposure to allergens failed to elicit such a response, supporting a distinction between different types of environmental exposure. uPM-induced senescence was independent of key macrophage activation pathways, specifically inflammasome and scavenger receptors. However, inhibition of the phagolysosome pathway abrogated senescence markers, supporting this phenotype's attribution to uPM phagocytosis. These data suggest that uPM exposure leads to macrophage senescence, which may contribute to immunopathology.
    MeSH term(s) Arachidonate 15-Lipoxygenase ; Vehicle Emissions ; Air Pollution ; Macrophages ; Phagosomes ; Dust
    Chemical Substances Arachidonate 15-Lipoxygenase (EC 1.13.11.33) ; Vehicle Emissions ; Dust
    Language English
    Publishing date 2024-04-14
    Publishing country United States
    Document type Journal Article
    ISSN 2573-7732
    ISSN (online) 2573-7732
    DOI 10.4049/immunohorizons.2300096
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  2. Article: Air pollution drives macrophage senescence through a phagolysosome-15-lipoxygenase pathway.

    Thomas, Sarah A / Yong, Hwan Mee / Rule, Ana M / Gour, Naina / Lajoie, Stephane

    bioRxiv : the preprint server for biology

    2024  

    Abstract: Urban particulate matter (uPM) poses significant health risks, particularly to the respiratory system. Fine particles, such as ... ...

    Abstract Urban particulate matter (uPM) poses significant health risks, particularly to the respiratory system. Fine particles, such as PM
    Language English
    Publishing date 2024-01-04
    Publishing country United States
    Document type Preprint
    DOI 10.1101/2024.01.04.574228
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  3. Article ; Online: A GPCR-neuropeptide axis dampens hyperactive neutrophils by promoting an alternative-like polarization during bacterial infection.

    Gour, Naina / Yong, Hwan Mee / Magesh, Aishwarya / Atakkatan, Aishwarya / Andrade, Felipe / Lajoie, Stephane / Dong, Xinzhong

    Immunity

    2024  Volume 57, Issue 2, Page(s) 333–348.e6

    Abstract: The notion that neutrophils exist as a homogeneous population is being replaced with the knowledge that neutrophils adopt different functional states. Neutrophils can have a pro-inflammatory phenotype or an anti-inflammatory state, but how these states ... ...

    Abstract The notion that neutrophils exist as a homogeneous population is being replaced with the knowledge that neutrophils adopt different functional states. Neutrophils can have a pro-inflammatory phenotype or an anti-inflammatory state, but how these states are regulated remains unclear. Here, we demonstrated that the neutrophil-expressed G-protein-coupled receptor (GPCR) Mrgpra1 is a negative regulator of neutrophil bactericidal functions. Mrgpra1-mediated signaling was driven by its ligand, neuropeptide FF (NPFF), which dictated the balance between pro- and anti-inflammatory programming. Specifically, the Mrgpra1-NPFF axis counter-regulated interferon (IFN) γ-mediated neutrophil polarization during acute lung infection by favoring an alternative-like polarization, suggesting that it may act to balance overzealous neutrophilic responses. Distinct, cross-regulated populations of neutrophils were the primary source of NPFF and IFNγ during infection. As a subset of neutrophils at steady state expressed NPFF, these findings could have broad implications in various infectious and inflammatory diseases. Therefore, a neutrophil-intrinsic pathway determines their cellular fate, function, and magnitude of infection.
    MeSH term(s) Humans ; Receptors, Neuropeptide/metabolism ; Neutrophils/metabolism ; Receptors, G-Protein-Coupled/genetics ; Receptors, G-Protein-Coupled/metabolism ; Neuropeptides ; Anti-Inflammatory Agents ; Bacterial Infections
    Chemical Substances Receptors, Neuropeptide ; Receptors, G-Protein-Coupled ; Neuropeptides ; Anti-Inflammatory Agents
    Language English
    Publishing date 2024-01-30
    Publishing country United States
    Document type Journal Article
    ZDB-ID 1217235-2
    ISSN 1097-4180 ; 1074-7613
    ISSN (online) 1097-4180
    ISSN 1074-7613
    DOI 10.1016/j.immuni.2024.01.003
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  4. Article ; Online: Epithelial Cell Regulation of Allergic Diseases.

    Gour, Naina / Lajoie, Stephane

    Current allergy and asthma reports

    2016  Volume 16, Issue 9, Page(s) 65

    Abstract: Allergic diseases, which have escalated in prevalence in recent years, arise as a result of maladaptive immune responses to ubiquitous environmental stimuli. Why only certain individuals mount inappropriate type 2 immune responses to these otherwise ... ...

    Abstract Allergic diseases, which have escalated in prevalence in recent years, arise as a result of maladaptive immune responses to ubiquitous environmental stimuli. Why only certain individuals mount inappropriate type 2 immune responses to these otherwise harmless allergens has remained an unanswered question. Mounting evidence suggests that the epithelium, by sensing its environment, is the central regulator of allergic diseases. Once considered to be a passive barrier to allergens, epithelial cells at mucosal surfaces are now considered to be the cornerstone of the allergic diathesis. Beyond their function as maintaining barrier at mucosal surfaces, mucosal epithelial cells through the secretion of mediators like IL-25, IL-33, and TSLP control the fate of downstream allergic immune responses. In this review, we will discuss the advances in recent years regarding the process of allergen recognition and secretion of soluble mediators by epithelial cells that shape the development of the allergic response.
    MeSH term(s) Allergens/immunology ; Animals ; Epithelial Cells/immunology ; Humans
    Chemical Substances Allergens
    Language English
    Publishing date 2016
    Publishing country United States
    Document type Journal Article ; Review
    ZDB-ID 2057370-4
    ISSN 1534-6315 ; 1529-7322
    ISSN (online) 1534-6315
    ISSN 1529-7322
    DOI 10.1007/s11882-016-0640-7
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  5. Article ; Online: Epigenetic regulation of epithelial dectin-1 through an IL-33-STAT3 axis in allergic disease.

    Yong, Hwan Mee / Gour, Naina / Sharma, Deepika / Khalil, Syed Muaz / Lane, Andrew P / Lajoie, Stephane

    Allergy

    2021  Volume 77, Issue 1, Page(s) 207–217

    Abstract: Allergic diseases arise in susceptible individuals in part because of decrements in protective pathways. The mechanism by which these anti-inflammatory molecules become repressed remains unclear. We have previously reported that epithelial dectin-1 ... ...

    Abstract Allergic diseases arise in susceptible individuals in part because of decrements in protective pathways. The mechanism by which these anti-inflammatory molecules become repressed remains unclear. We have previously reported that epithelial dectin-1 prevents aberrant type 2 responses and is downregulated in the epithelium of allergic patients. Here, we report that dectin-1 is constitutively expressed by the respiratory epithelium in humans and that IL-33 specifically acts as a repressor of dectin-1. Mechanistically, this occurs via IL-33-dependent STAT3 activation and the subsequent repression of the dectin-1 gene, CLEC7A. We have identified a novel enhancer region upstream of the proximal promoter of CLEC7A that is only accessible in epithelial cells, but not in hematopoietic cells. Epigenetic repression of CLEC7A through this newly identified locus, downstream of an aberrant IL-33-STAT3 axis, occurs in the epithelium of allergic individuals. Collectively, our data identify a mechanism of epigenetic fine-tuning of dectin-1 expression in epithelial cells that may participate in allergenicity.
    MeSH term(s) Animals ; Cell Line ; Epigenesis, Genetic ; Humans ; Hypersensitivity/genetics ; Hypersensitivity/metabolism ; Interleukin-33/metabolism ; Lectins, C-Type/genetics ; Lectins, C-Type/metabolism ; Mice ; Mice, Knockout ; STAT3 Transcription Factor/genetics ; STAT3 Transcription Factor/metabolism
    Chemical Substances CLEC7A protein, human ; Interleukin-33 ; Lectins, C-Type ; STAT3 Transcription Factor ; STAT3 protein, human
    Language English
    Publishing date 2021-05-31
    Publishing country Denmark
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 391933-x
    ISSN 1398-9995 ; 0105-4538
    ISSN (online) 1398-9995
    ISSN 0105-4538
    DOI 10.1111/all.14898
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  6. Article ; Online: New twist on an ancient innate immune pathway.

    Lajoie, Stephane / Wills-Karp, Marsha

    Immunity

    2013  Volume 39, Issue 6, Page(s) 1000–1002

    Abstract: Activation of the complement system has long been known to be regulated by a series of steps involving fluid-phase convertases. In this issue of Immunity, Liszewski et al. (2013) report the discovery of an intracellular cathepsin-L-dependent C3 ... ...

    Abstract Activation of the complement system has long been known to be regulated by a series of steps involving fluid-phase convertases. In this issue of Immunity, Liszewski et al. (2013) report the discovery of an intracellular cathepsin-L-dependent C3 activation pathway.
    MeSH term(s) B-Lymphocyte Subsets/cytology ; CD4-Positive T-Lymphocytes/immunology ; Cathepsin L/metabolism ; Cell Differentiation ; Complement Activation/physiology ; Complement C3/metabolism ; Homeostasis/physiology ; Humans
    Chemical Substances Complement C3 ; CTSL protein, human (EC 3.4.22.15) ; Cathepsin L (EC 3.4.22.15)
    Language English
    Publishing date 2013-12-11
    Publishing country United States
    Document type Journal Article ; Comment
    ZDB-ID 1217235-2
    ISSN 1097-4180 ; 1074-7613
    ISSN (online) 1097-4180
    ISSN 1074-7613
    DOI 10.1016/j.immuni.2013.11.015
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  7. Article ; Online: Interleukin 13 (IL-13) alters hypoxia-associated genes and upregulates CD73.

    Khalil, Syed Muaz / Bernstein, Isaac / Kulaga, Heather / Gour, Naina / Rowan, Nicholas / Lajoie, Stephane / Lane, Andrew P

    International forum of allergy & rhinology

    2020  Volume 10, Issue 9, Page(s) 1096–1102

    Abstract: Background: Interleukin 13 (IL-13) is a pleiotropic cytokine that has been shown to be important in the pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP) and other type 2 inflammation-related diseases. Increased IL-13 expression can ... ...

    Abstract Background: Interleukin 13 (IL-13) is a pleiotropic cytokine that has been shown to be important in the pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP) and other type 2 inflammation-related diseases. Increased IL-13 expression can elicit several pro-inflammatory effects, including eosinophilia, and pathology such as increased mucus secretion. Polypogenesis in chronic rhinosinusitis (CRS) can be caused by hypoxia, which can also lead to hyperpermeability of airway epithelium and epithelium-to-mesenchymal translation through the upregulation of hypoxia-associated genes, such as HIF1. Whether T-helper 2 (Th2) inflammatory cytokines, such as IL-13, can also induce sinonasal epithelial hypoxia-associated genes is currently unknown.
    Methods: Human air-liquid interface (ALI) sinonasal epithelial cell cultures treated with recombinant IL-13 were analyzed by real-time polymerase chain reaction (PCR) and flow cytometry to determine the effect on epithelial cells.
    Results: Whole tissue from CRSwNP subjects showed increased HIF1A gene expression. Treatment of fully differentiated human ALI cultures with IL-13 resulted in a concurrent increase in HIF1A and ARNT messenger RNA (mRNA) expression. However, the level of EPAS1 expression was significantly reduced. IL-13 also had a dose-dependent response on the expression of HIF genes and the time course experiment showed peak expression of HIF1A and ARNT at 5 to 7 days poststimulation. Remarkably, CD73 surface expression also peaked at day 5 poststimulation.
    Conclusion: Our data suggests that IL-13 can induce hypoxia signaling pathway genes leading to surface expression of CD73, which has an anti-inflammatory effect.
    MeSH term(s) Chronic Disease ; Epithelial Cells/pathology ; Humans ; Hypoxia ; Interleukin-13/genetics ; Interleukin-33 ; Nasal Mucosa/pathology ; Nasal Polyps/genetics ; Nasal Polyps/pathology ; Rhinitis/genetics ; Rhinitis/pathology ; Sinusitis/genetics ; Sinusitis/pathology
    Chemical Substances Interleukin-13 ; Interleukin-33
    Language English
    Publishing date 2020-07-16
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 2625826-2
    ISSN 2042-6984 ; 2042-6976
    ISSN (online) 2042-6984
    ISSN 2042-6976
    DOI 10.1002/alr.22630
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  8. Article ; Online: C3a is required for ILC2 function in allergic airway inflammation.

    Gour, Naina / Smole, Ursula / Yong, Hwan-Mee / Lewkowich, Ian P / Yao, Nu / Singh, Anju / Gabrielson, Edward / Wills-Karp, Marsha / Lajoie, Stephane

    Mucosal immunology

    2018  Volume 11, Issue 6, Page(s) 1653–1662

    Abstract: Aberrant type 2 responses underlie the pathologies in allergic diseases like asthma, yet, our understanding of the mechanisms that drive them remains limited. Recent evidence suggests that dysregulated innate immune factors can perpetuate asthma ... ...

    Abstract Aberrant type 2 responses underlie the pathologies in allergic diseases like asthma, yet, our understanding of the mechanisms that drive them remains limited. Recent evidence suggests that dysregulated innate immune factors can perpetuate asthma pathogenesis. In susceptible individuals, allergen exposure triggers the activation of complement, a major arm of innate immunity, leading to the aberrant generation of the C3a anaphylatoxin. C3 and C3a have been shown to be important for the development of Th2 responses, yet remarkably, the mechanisms by which C3a regulates type 2 immunity are relatively unknown. We demonstrate a central role for C3a in driving type 2 innate lymphoid cells (ILC2)-mediated inflammation in response to allergen and IL-33. Our data suggests that ILC2 recruitment is C3a-dependent. Further, we show that ILC2s directly respond to C3a, promoting type 2 responses by specifically: (1) inducing IL-13 and granulocyte-macrophage colony-stimulating factor, whereas inhibiting IL-10 production from ILC2; and (2) enhancing their antigen-presenting capability during ILC-T-cell cross-talk. In summary, we identify a novel mechanism by which C3a can mediate aberrant type 2 responses to aeroallergen exposure, which involves a yet unrecognized cross-talk between two major innate immune components-complement and group 2 innate lymphoid cells.
    MeSH term(s) Allergens/immunology ; Animals ; Antigen Presentation ; Asthma/immunology ; Cell Communication ; Cell Movement ; Cells, Cultured ; Complement C3a/metabolism ; Granulocyte-Macrophage Colony-Stimulating Factor/metabolism ; Hypersensitivity/immunology ; Immunity, Innate ; Inflammation/immunology ; Interleukin-10/metabolism ; Interleukin-13/metabolism ; Interleukin-33/immunology ; Lymphocytes/immunology ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Mice, Knockout ; Respiratory System/immunology ; Th2 Cells/immunology
    Chemical Substances Allergens ; Interleukin-13 ; Interleukin-33 ; Interleukin-10 (130068-27-8) ; Complement C3a (80295-42-7) ; Granulocyte-Macrophage Colony-Stimulating Factor (83869-56-1)
    Language English
    Publishing date 2018-08-13
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 2411370-0
    ISSN 1935-3456 ; 1933-0219
    ISSN (online) 1935-3456
    ISSN 1933-0219
    DOI 10.1038/s41385-018-0064-x
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  9. Article: Unique pulmonary immunotoxicological effects of urban PM are not recapitulated solely by carbon black, diesel exhaust or coal fly ash

    Gour, Naina / Sudini, Kuladeep / Khalil, Syed Muaz / Rule, Ana M / Lees, Peter / Gabrielson, Edward / Groopman, John D / Lajoie, Stephane / Singh, Anju

    Environmental research. 2018 Feb., v. 161

    2018  

    Abstract: Exposure to particulate matter (PM) is increasing worldwide as a result of increased human activity, the rapid industrialization of developing countries, and effects of climate change. Adverse effects of PM on human health are well documented, and ... ...

    Abstract Exposure to particulate matter (PM) is increasing worldwide as a result of increased human activity, the rapid industrialization of developing countries, and effects of climate change. Adverse effects of PM on human health are well documented, and because PM exposure occurs mostly through the airways, PM has especially deleterious impact on the lungs.We investigated whether surrogate PM particles like carbon black (CB), diesel exhaust particle (DEP), coal fly ash (CFA) can recapitulate the allergic airway inflammatory response induced by urban particulate matter.We compared the pro-inflammatory potential of urban PM collected from New York (NYC) and Baltimore (Balt) with CB, DEP and CFA surrogate PM particles. Eight to ten weeks old BALB/cJ mice were exposed through the airways to particulate material, and markers of airway inflammation were determined. Specifically, we assessed cellular influx, mucus production, lung function, cytokine levels as well as immune cell profiling of the lungs.Herein, we demonstrate that exposure to equivalent mass of stand-alone surrogate PM particles like CB, DEP and CFA, fails to induce significant airway inflammatory response seen after similar exposure to urban PMs. Specifically, we observe that PM collected from New York (NYC) and Baltimore city (Balt) triggers a mixed Th2/Th17 response accompanied by eosinophilic and neutrophilic influx, mucus production and airway hyperresponsiveness (AHR). Although the immune profile of NYC and Baltimore PMs are similar, they demonstrate considerable differences in their potency. Baltimore PM induced more robust airway inflammation, AHR, and Th2 cytokine production, possibly due to the greater metal content in Baltimore PM.Urban particulate matter with its unique physiochemical properties and heterogeneous composition elicits a mixed Th2/Th17 allergic airway response that is not seen after similar exposures to surrogate PM particles.
    Keywords adverse effects ; climate change ; coal fly ash ; cytokines ; developing countries ; human health ; humans ; industrialization ; inflammation ; lung function ; mice ; mucus ; particulates ; soot ; New York
    Language English
    Dates of publication 2018-02
    Size p. 304-313.
    Publishing place Elsevier Inc.
    Document type Article
    ZDB-ID 205699-9
    ISSN 1096-0953 ; 0013-9351
    ISSN (online) 1096-0953
    ISSN 0013-9351
    DOI 10.1016/j.envres.2017.10.041
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

  10. Article ; Online: Unique pulmonary immunotoxicological effects of urban PM are not recapitulated solely by carbon black, diesel exhaust or coal fly ash.

    Gour, Naina / Sudini, Kuladeep / Khalil, Syed Muaz / Rule, Ana M / Lees, Peter / Gabrielson, Edward / Groopman, John D / Lajoie, Stephane / Singh, Anju

    Environmental research

    2017  Volume 161, Page(s) 304–313

    Abstract: Background: Exposure to particulate matter (PM) is increasing worldwide as a result of increased human activity, the rapid industrialization of developing countries, and effects of climate change. Adverse effects of PM on human health are well ... ...

    Abstract Background: Exposure to particulate matter (PM) is increasing worldwide as a result of increased human activity, the rapid industrialization of developing countries, and effects of climate change. Adverse effects of PM on human health are well documented, and because PM exposure occurs mostly through the airways, PM has especially deleterious impact on the lungs.
    Objective: We investigated whether surrogate PM particles like carbon black (CB), diesel exhaust particle (DEP), coal fly ash (CFA) can recapitulate the allergic airway inflammatory response induced by urban particulate matter.
    Methods: We compared the pro-inflammatory potential of urban PM collected from New York (NYC) and Baltimore (Balt) with CB, DEP and CFA surrogate PM particles. Eight to ten weeks old BALB/cJ mice were exposed through the airways to particulate material, and markers of airway inflammation were determined. Specifically, we assessed cellular influx, mucus production, lung function, cytokine levels as well as immune cell profiling of the lungs.
    Results: Herein, we demonstrate that exposure to equivalent mass of stand-alone surrogate PM particles like CB, DEP and CFA, fails to induce significant airway inflammatory response seen after similar exposure to urban PMs. Specifically, we observe that PM collected from New York (NYC) and Baltimore city (Balt) triggers a mixed Th2/Th17 response accompanied by eosinophilic and neutrophilic influx, mucus production and airway hyperresponsiveness (AHR). Although the immune profile of NYC and Baltimore PMs are similar, they demonstrate considerable differences in their potency. Baltimore PM induced more robust airway inflammation, AHR, and Th2 cytokine production, possibly due to the greater metal content in Baltimore PM.
    Conclusions: Urban particulate matter with its unique physiochemical properties and heterogeneous composition elicits a mixed Th2/Th17 allergic airway response that is not seen after similar exposures to surrogate PM particles.
    MeSH term(s) Animals ; Baltimore ; Carbon ; Coal ; Coal Ash/adverse effects ; Humans ; Hypersensitivity/etiology ; Inflammation/chemically induced ; Lung/drug effects ; Mice ; New York ; Particulate Matter/adverse effects ; Soot ; Vehicle Emissions
    Chemical Substances Coal ; Coal Ash ; Particulate Matter ; Soot ; Vehicle Emissions ; Carbon (7440-44-0)
    Language English
    Publishing date 2017-11-24
    Publishing country Netherlands
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 205699-9
    ISSN 1096-0953 ; 0013-9351
    ISSN (online) 1096-0953
    ISSN 0013-9351
    DOI 10.1016/j.envres.2017.10.041
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

To top