LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 10 of total 193

Search options

  1. Article ; Online: Indoleamine dioxygenase and tryptophan dioxygenase activities are regulated through control of cell heme allocation by nitric oxide.

    Biswas, Pranjal / Stuehr, Dennis J

    The Journal of biological chemistry

    2023  Volume 299, Issue 6, Page(s) 104753

    Abstract: Indoleamine-2, 3-dioxygenase (IDO1) and Tryptophan-2, 3-dioxygenase (TDO) catalyze the conversion of L-tryptophan to N-formyl-kynurenine and thus play primary roles in metabolism, inflammation, and tumor immune surveillance. Because their activities ... ...

    Abstract Indoleamine-2, 3-dioxygenase (IDO1) and Tryptophan-2, 3-dioxygenase (TDO) catalyze the conversion of L-tryptophan to N-formyl-kynurenine and thus play primary roles in metabolism, inflammation, and tumor immune surveillance. Because their activities depend on their heme contents, which vary in biological settings and go up or down in a dynamic manner, we studied how their heme levels may be impacted by nitric oxide (NO) in mammalian cells. We utilized cells expressing TDO or IDO1 either naturally or via transfection and determined their activities, heme contents, and expression levels as a function of NO exposure. We found NO has a bimodal effect: a narrow range of low NO exposure promoted cells to allocate heme into the heme-free TDO and IDO1 populations and consequently boosted their heme contents and activities 4- to 6-fold, while beyond this range the NO exposure transitioned to have a negative impact on their heme contents and activities. NO did not alter dioxygenase protein expression levels, and its bimodal impact was observed when NO was released by a chemical donor or was generated naturally by immune-stimulated macrophage cells. NO-driven heme allocations to IDO1 and TDO required participation of a GAPDH-heme complex and for IDO1 required chaperone Hsp90 activity. Thus, cells can up- or downregulate their IDO1 and TDO activities through a bimodal control of heme allocation by NO. This mechanism has important biomedical implications and helps explain why the IDO1 and TDO activities in animals go up and down in response to immune stimulation.
    MeSH term(s) Animals ; Heme/metabolism ; Indoleamine-Pyrrole 2,3,-Dioxygenase/chemistry ; Indoleamine-Pyrrole 2,3,-Dioxygenase/metabolism ; Mammals/metabolism ; Nitric Oxide ; Tryptophan/metabolism ; Tryptophan Oxygenase/chemistry ; Tryptophan Oxygenase/metabolism
    Chemical Substances Heme (42VZT0U6YR) ; Indoleamine-Pyrrole 2,3,-Dioxygenase ; Nitric Oxide (31C4KY9ESH) ; Tryptophan (8DUH1N11BX) ; Tryptophan Oxygenase (EC 1.13.11.11)
    Language English
    Publishing date 2023-04-26
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 2997-x
    ISSN 1083-351X ; 0021-9258
    ISSN (online) 1083-351X
    ISSN 0021-9258
    DOI 10.1016/j.jbc.2023.104753
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  2. Article ; Online: BAY58-2667 Activates Different Soluble Guanylyl Cyclase Species by Distinct Mechanisms that Indicate Its Principal Target in Cells is the Heme-Free Soluble Guanylyl Cyclase-Heat Shock Protein 90 Complex.

    Dai, Yue / Stuehr, Dennis J

    Molecular pharmacology

    2023  Volume 103, Issue 5, Page(s) 286–296

    Abstract: Nitric oxide (NO)-unresponsive forms of soluble guanylyl cyclase (sGC) exist naturally and in disease can disable NO-sGC-cGMP signaling. Agonists like BAY58-2667 (BAY58) target these sGC forms, but their mechanisms of action in living cells are unclear. ... ...

    Abstract Nitric oxide (NO)-unresponsive forms of soluble guanylyl cyclase (sGC) exist naturally and in disease can disable NO-sGC-cGMP signaling. Agonists like BAY58-2667 (BAY58) target these sGC forms, but their mechanisms of action in living cells are unclear. We studied rat lung fibroblast-6 cells and human airway smooth muscle cells that naturally express sGC and HEK293 cells that we transfected to express sGC and variants. Cells were cultured to build up different forms of sGC, and we used fluorescence and FRET-based measures to monitor BAY58-driven cGMP production and any protein partner exchange or heme loss events that may occur for each sGC species. We found that: (i) BAY58 activated cGMP production by the apo-sGC
    MeSH term(s) Rats ; Animals ; Humans ; Soluble Guanylyl Cyclase/metabolism ; Heme/metabolism ; HEK293 Cells ; Signal Transduction ; Nitric Oxide/metabolism ; Heat-Shock Proteins/metabolism ; Guanylate Cyclase/metabolism ; Cyclic GMP/metabolism
    Chemical Substances Soluble Guanylyl Cyclase (EC 4.6.1.2) ; Heme (42VZT0U6YR) ; Nitric Oxide (31C4KY9ESH) ; Heat-Shock Proteins ; Guanylate Cyclase (EC 4.6.1.2) ; Cyclic GMP (H2D2X058MU)
    Language English
    Publishing date 2023-03-03
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 124034-1
    ISSN 1521-0111 ; 0026-895X
    ISSN (online) 1521-0111
    ISSN 0026-895X
    DOI 10.1124/molpharm.122.000624
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  3. Article ; Online: Functional maturation of cytochromes P450 3A4 and 2D6 relies on GAPDH- and Hsp90-Dependent heme allocation.

    Islam, Sidra / Jayaram, Dhanya Thamaraparambil / Biswas, Pranjal / Stuehr, Dennis J

    The Journal of biological chemistry

    2024  Volume 300, Issue 2, Page(s) 105633

    Abstract: Cytochrome P450 3A4 and 2D6 (EC 1.14.13.97 and 1.14.14.1; CYP3A4 and 2D6) are heme-containing enzymes that catalyze the oxidation of a wide number of xenobiotic and drug substrates and thus broadly impact human biology and pharmacologic therapies. ... ...

    Abstract Cytochrome P450 3A4 and 2D6 (EC 1.14.13.97 and 1.14.14.1; CYP3A4 and 2D6) are heme-containing enzymes that catalyze the oxidation of a wide number of xenobiotic and drug substrates and thus broadly impact human biology and pharmacologic therapies. Although their activities are directly proportional to their heme contents, little is known about the cellular heme delivery and insertion processes that enable their maturation to functional form. We investigated the potential involvement of GAPDH and chaperone Hsp90, based on our previous studies linking these proteins to intracellular heme allocation. We studied heme delivery and insertion into CYP3A4 and 2D6 after they were transiently expressed in HEK293T and GlyA CHO cells or when naturally expressed in HEPG2 cells in response to rifampicin, and also investigated their associations with GAPDH and Hsp90 in cells. The results indicate that GAPDH and its heme binding function is involved in delivery of mitochondria-generated heme to apo-CYP3A4 and 2D6, and that cell chaperone Hsp90 is additionally involved in driving their heme insertions. Uncovering how cells allocate heme to CYP3A4 and 2D6 provides new insight on their maturation processes and how this may help to regulate their functions in health and disease.
    MeSH term(s) Animals ; Cricetinae ; Humans ; Cricetulus ; Cytochrome P-450 CYP3A/genetics ; Cytochrome P-450 CYP3A/metabolism ; HEK293 Cells ; Heme/metabolism ; HSP90 Heat-Shock Proteins/genetics ; HSP90 Heat-Shock Proteins/metabolism ; Molecular Chaperones/metabolism ; Oxidation-Reduction
    Chemical Substances Cytochrome P-450 CYP3A (EC 1.14.14.1) ; Heme (42VZT0U6YR) ; HSP90 Heat-Shock Proteins ; Molecular Chaperones ; GAPDH protein, human (EC 1.2.1.12) ; CYP2D6 protein, human ; CYP3A4 protein, human (EC 1.14.14.55)
    Language English
    Publishing date 2024-01-08
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2997-x
    ISSN 1083-351X ; 0021-9258
    ISSN (online) 1083-351X
    ISSN 0021-9258
    DOI 10.1016/j.jbc.2024.105633
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  4. Article ; Online: Inactivation of soluble guanylyl cyclase in living cells proceeds without loss of haem and involves heterodimer dissociation as a common step.

    Dai, Yue / Stuehr, Dennis J

    British journal of pharmacology

    2021  Volume 179, Issue 11, Page(s) 2505–2518

    Abstract: Background and purpose: Nitric oxide (NO) activates soluble guanylyl cyclase (sGC) for cGMP production, but in disease, sGC becomes insensitive towards NO activation. What changes occur to sGC during its inactivation in cells is not clear.: ... ...

    Abstract Background and purpose: Nitric oxide (NO) activates soluble guanylyl cyclase (sGC) for cGMP production, but in disease, sGC becomes insensitive towards NO activation. What changes occur to sGC during its inactivation in cells is not clear.
    Experimental approach: We utilized HEK293 cells expressing sGC proteins to study the changes that occur regarding its haem content, heterodimer status and sGCβ protein partners when the cells were given the oxidant ODQ or the NO donor NOC12 to inactivate sGC. Haem content of sGCβ was monitored in live cells through use of a fluorescent-labelled sGCβ construct, whereas sGC heterodimer status and protein interactions were studied by Western blot analysis. Experiments with purified proteins were also performed.
    Key results: ODQ- or NOC12-driven inactivation of sGC in HEK293 cells was associated with haem oxidation (by ODQ), S-nitrosation of the sGCβ subunit (by NOC12), sGC heterodimer breakup and association of the freed sGCβ subunit with cell chaperone Hsp90. These changes occurred without detectable loss of haem from the sGCβ reporter construct. Treating a purified ferrous haem-containing sGCβ with ODQ or NOC12 caused it to bind with Hsp90 without showing any haem loss.
    Conclusion and implications: Oxidative (ODQ) or nitrosative (NOC12) inactivation of cell sGC involves sGC heterodimer dissociation and rearrangement of the sGCβ protein partners without any haem loss from sGCβ. Clarifying what changes do and do not occur to sGC during its inactivation in cells may direct strategies to preserve or recover NO-dependent cGMP signalling in health and disease.
    Linked articles: This article is part of a themed issue on cGMP Signalling in Cell Growth and Survival. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v179.11/issuetoc.
    MeSH term(s) Cyclic GMP/metabolism ; Guanylate Cyclase/metabolism ; HEK293 Cells ; Heme/metabolism ; Humans ; Nitric Oxide/metabolism ; Receptors, Cytoplasmic and Nuclear ; Soluble Guanylyl Cyclase/metabolism
    Chemical Substances Receptors, Cytoplasmic and Nuclear ; Nitric Oxide (31C4KY9ESH) ; Heme (42VZT0U6YR) ; Guanylate Cyclase (EC 4.6.1.2) ; Soluble Guanylyl Cyclase (EC 4.6.1.2) ; Cyclic GMP (H2D2X058MU)
    Language English
    Publishing date 2021-06-16
    Publishing country England
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 80081-8
    ISSN 1476-5381 ; 0007-1188
    ISSN (online) 1476-5381
    ISSN 0007-1188
    DOI 10.1111/bph.15527
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  5. Article ; Online: Regional variations in allergen-induced airway inflammation correspond to changes in soluble guanylyl cyclase heme and expression of heme oxygenase-1.

    Sumi, Mamta P / Westcott, Rosemary / Stuehr, Eric / Ghosh, Chaitali / Stuehr, Dennis J / Ghosh, Arnab

    FASEB journal : official publication of the Federation of American Societies for Experimental Biology

    2024  Volume 38, Issue 6, Page(s) e23572

    Abstract: Asthma is characterized by airway remodeling and hyperreactivity. Our earlier studies determined that the nitric oxide (NO)-soluble guanylyl cyclase (sGC)-cGMP pathway plays a significant role in human lung bronchodilation. However, this bronchodilation ... ...

    Abstract Asthma is characterized by airway remodeling and hyperreactivity. Our earlier studies determined that the nitric oxide (NO)-soluble guanylyl cyclase (sGC)-cGMP pathway plays a significant role in human lung bronchodilation. However, this bronchodilation is dysfunctional in asthma due to high NO levels, which cause sGC to become heme-free and desensitized to its natural activator, NO. In order to determine how asthma impacts the various lung segments/lobes, we mapped the inflammatory regions of lungs to determine whether such regions coincided with molecular signatures of sGC dysfunction. We demonstrate using murine models of asthma (OVA and CFA/HDM) that the inflamed segments of these murine lungs can be tracked by upregulated expression of HO1 and these regions in turn overlap with regions of heme-free sGC as evidenced by a decreased sGC-α1β1 heterodimer and an increased response to heme-independent sGC activator, BAY 60-2770, relative to naïve uninflamed regions. We also find that NO generated from iNOS upregulation in the inflamed segments has a higher impact on developing heme-free sGC as increasing iNOS activity correlates linearly with elevated heme-independent sGC activation. This excess NO works by affecting the epithelial lung hemoglobin (Hb) to become heme-free in asthma, thereby causing the Hb to lose its NO scavenging function and exposing the underlying smooth muscle sGC to excess NO, which in turn becomes heme-free. Recognition of these specific lung segments enhances our understanding of the inflamed lungs in asthma with the ultimate aim to evaluate potential therapies and suggest that regional and not global inflammation impacts lung function in asthma.
    MeSH term(s) Animals ; Humans ; Mice ; Allergens ; Asthma ; Heme ; Heme Oxygenase-1/metabolism ; Inflammation ; Nitric Oxide ; Soluble Guanylyl Cyclase
    Chemical Substances Allergens ; Heme (42VZT0U6YR) ; Heme Oxygenase-1 (EC 1.14.14.18) ; Nitric Oxide (31C4KY9ESH) ; Soluble Guanylyl Cyclase (EC 4.6.1.2) ; Hmox1 protein, mouse (EC 1.14.14.18)
    Language English
    Publishing date 2024-03-21
    Publishing country United States
    Document type Journal Article
    ZDB-ID 639186-2
    ISSN 1530-6860 ; 0892-6638
    ISSN (online) 1530-6860
    ISSN 0892-6638
    DOI 10.1096/fj.202301626RRR
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  6. Article: Functional interactions between NADPH oxidase 5 and actin.

    Richter, Samantha M / Massman, Lilyanna C / Stuehr, Dennis J / Sweeny, Elizabeth A

    Frontiers in cell and developmental biology

    2023  Volume 11, Page(s) 1116833

    Abstract: NADPH oxidase 5 (NOX5) is a transmembrane oxidative signaling enzyme which produces superoxide in response to intracellular calcium flux. Increasing evidence indicates that NOX5 is involved in a variety of physiological processes as well as human disease, ...

    Abstract NADPH oxidase 5 (NOX5) is a transmembrane oxidative signaling enzyme which produces superoxide in response to intracellular calcium flux. Increasing evidence indicates that NOX5 is involved in a variety of physiological processes as well as human disease, however, details of NOX5 signaling pathways and targets of NOX5 mediated oxidative modifications remain poorly resolved. Actin dynamics have previously been shown to be modulated by oxidative modification, however, a direct connection to NOX5 expression and activity has not been fully explored. Here we show that NOX5 and actin interact in the cell, and each modulate the activity of the other. Using actin effector molecules jasplakinolide, cytochalasin D and latrunculin A, we show that changes in actin dynamics affect NOX5 superoxide production. In tandem, NOX5 oxidatively modifies actin, and shifts the ratio of filamentous to monomeric actin. Finally, we show that knockdown of NOX5 in the pancreatic cancer cell line PSN-1 impairs cell migration. Together our findings indicate an important link between actin dynamics and oxidative signaling through NOX5.
    Language English
    Publishing date 2023-01-26
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2737824-X
    ISSN 2296-634X
    ISSN 2296-634X
    DOI 10.3389/fcell.2023.1116833
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  7. Article ; Online: Indoleamine dioxygenase and tryptophan dioxygenase activities are regulated through GAPDH- and Hsp90-dependent control of their heme levels.

    Biswas, Pranjal / Dai, Yue / Stuehr, Dennis J

    Free radical biology & medicine

    2022  Volume 180, Page(s) 179–190

    Abstract: Indoleamine-2, 3-dioxygenase (IDO1) and Tryptophan-2, 3-dioxygense (TDO) are heme-containing dioxygenases that catalyze the conversion of tryptophan to N-formyl-kynurenine and thus enable generation of l-kynurenine and related metabolites that govern the ...

    Abstract Indoleamine-2, 3-dioxygenase (IDO1) and Tryptophan-2, 3-dioxygense (TDO) are heme-containing dioxygenases that catalyze the conversion of tryptophan to N-formyl-kynurenine and thus enable generation of l-kynurenine and related metabolites that govern the immune response and broadly impact human biology. Given that TDO and IDO1 activities are directly proportional to their heme contents, it is important to understand their heme delivery and insertion processes. Early studies established that TDO and IDO1 heme levels are sub-saturating in vivo and subject to change but did not identify the cellular mechanisms that provide their heme or enable dynamic changes in their heme contents. We investigated the potential involvement of GAPDH and chaperone Hsp90, based on our previous studies linking these proteins to intracellular heme allocation. We studied heme delivery and insertion into IDO1 and TDO expressed in both normal and heme-deficient HEK293T cells and into IDO1 naturally expressed in HeLa cells in response to IFN-γ, and also investigated the interactions of TDO and IDO1 with GAPDH and Hsp90 in cells and among their purified forms. We found that GAPDH delivered both mitochondrially-generated and exogenous heme to apo-IDO1 and apo-TDO in cells, potentially through a direct interaction with either enzyme. In contrast, we found Hsp90 interacted with apo-IDO1 but not with apo-TDO, and was only needed to drive heme insertion into apo-IDO1. By uncovering the cellular processes that allocate heme to IDO1 and TDO, our study provides new insight on how their activities and l-kynurenine production may be controlled in health and disease.
    MeSH term(s) Enzyme Inhibitors ; HEK293 Cells ; HeLa Cells ; Heme ; Humans ; Indoleamine-Pyrrole 2,3,-Dioxygenase/genetics ; Tryptophan/metabolism ; Tryptophan Oxygenase/genetics ; Tryptophan Oxygenase/metabolism
    Chemical Substances Enzyme Inhibitors ; Indoleamine-Pyrrole 2,3,-Dioxygenase ; Heme (42VZT0U6YR) ; Tryptophan (8DUH1N11BX) ; Tryptophan Oxygenase (EC 1.13.11.11)
    Language English
    Publishing date 2022-01-17
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 807032-5
    ISSN 1873-4596 ; 0891-5849
    ISSN (online) 1873-4596
    ISSN 0891-5849
    DOI 10.1016/j.freeradbiomed.2022.01.008
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  8. Article ; Online: A natural heme deficiency exists in biology that allows nitric oxide to control heme protein functions by regulating cellular heme distribution

    Stuehr, Dennis J. / Biswas, Pranjal / Dai, Yue / Ghosh, Arnab / Islam, Sidra / Jayaram, Dhanya Thamaraparambil

    BioEssays. 2023 Aug., v. 45, no. 8 p.e2300055-

    2023  

    Abstract: A natural heme deficiency that exists in cells outside of the circulation broadly compromises the heme contents and functions of heme proteins in cells and tissues. Recently, we found that the signaling molecule, nitric oxide (NO), can trigger or repress ...

    Abstract A natural heme deficiency that exists in cells outside of the circulation broadly compromises the heme contents and functions of heme proteins in cells and tissues. Recently, we found that the signaling molecule, nitric oxide (NO), can trigger or repress the deployment of intracellular heme in a concentration‐dependent hormetic manner. This uncovers a new role for NO and sets the stage for it to shape numerous biological processes by controlling heme deployment and consequent heme protein functions in biology.
    Keywords heme ; heme proteins ; nitric oxide
    Language English
    Dates of publication 2023-08
    Publishing place John Wiley & Sons, Ltd
    Document type Article ; Online
    Note JOURNAL ARTICLE
    ZDB-ID 50140-2
    ISSN 1521-1878 ; 0265-9247
    ISSN (online) 1521-1878
    ISSN 0265-9247
    DOI 10.1002/bies.202300055
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

  9. Article ; Online: NO rapidly mobilizes cellular heme to trigger assembly of its own receptor.

    Dai, Yue / Faul, Emily M / Ghosh, Arnab / Stuehr, Dennis J

    Proceedings of the National Academy of Sciences of the United States of America

    2022  Volume 119, Issue 4

    Abstract: Nitric oxide (NO) signaling in biology relies on its activating cyclic guanosine monophosphate (cGMP) production by the NO receptor soluble guanylyl cyclase (sGC). sGC must obtain heme and form a heterodimer to become functional, but paradoxically often ... ...

    Abstract Nitric oxide (NO) signaling in biology relies on its activating cyclic guanosine monophosphate (cGMP) production by the NO receptor soluble guanylyl cyclase (sGC). sGC must obtain heme and form a heterodimer to become functional, but paradoxically often exists as an immature heme-free form in cells and tissues. Based on our previous finding that NO can drive sGC maturation, we investigated its basis by utilizing a fluorescent sGC construct whose heme level can be monitored in living cells. We found that NO generated at physiologic levels quickly triggered cells to mobilize heme to immature sGC. This occurred when NO was generated within cells or by neighboring cells, began within seconds of NO exposure, and led cells to construct sGC heterodimers and thus increase their active sGC level by several-fold. The NO-triggered heme deployment involved cellular glyceraldehyde-3-phosphate dehydrogenase (GAPDH)-heme complexes and required the chaperone hsp90, and the newly formed sGC heterodimers remained functional long after NO generation had ceased. We conclude that NO at physiologic levels triggers assembly of its own receptor by causing a rapid deployment of cellular heme. Redirecting cellular heme in response to NO is a way for cells and tissues to modulate their cGMP signaling and to more generally tune their hemeprotein activities wherever NO biosynthesis takes place.
    MeSH term(s) Animals ; Calcium ; Cyclic GMP ; Glyceraldehyde-3-Phosphate Dehydrogenases/metabolism ; Guanylate Cyclase/metabolism ; HSP90 Heat-Shock Proteins/metabolism ; Heme/metabolism ; Humans ; Mice ; Models, Biological ; Nitric Oxide/metabolism ; Protein Binding ; Protein Multimerization ; Protein Transport ; Receptors, Cell Surface/metabolism ; Signal Transduction ; Soluble Guanylyl Cyclase/metabolism
    Chemical Substances HSP90 Heat-Shock Proteins ; Receptors, Cell Surface ; heme receptor ; Nitric Oxide (31C4KY9ESH) ; Heme (42VZT0U6YR) ; Glyceraldehyde-3-Phosphate Dehydrogenases (EC 1.2.1.-) ; Guanylate Cyclase (EC 4.6.1.2) ; Soluble Guanylyl Cyclase (EC 4.6.1.2) ; Cyclic GMP (H2D2X058MU) ; Calcium (SY7Q814VUP)
    Language English
    Publishing date 2022-01-20
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 209104-5
    ISSN 1091-6490 ; 0027-8424
    ISSN (online) 1091-6490
    ISSN 0027-8424
    DOI 10.1073/pnas.2115774119
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  10. Article: Regions of Inflammation in mouse asthma correspond to regions of heme-free soluble guanylyl cyclase and can be tracked by marked expression of heme-oxygenase-1.

    Sumi, Mamta / Westcott, Rosemary / Stuehr, Eric / Ghosh, Chaitali / Stuehr, Dennis J / Ghosh, Arnab

    bioRxiv : the preprint server for biology

    2023  

    Abstract: Asthma is characterized by airway remodeling and hyperreactivity. Our earlier studies determined that the Nitric Oxide (NO)-soluble Guanylyl Cyclase (sGC)-cGMP pathway plays a significant role in human lung bronchodilation. However this bronchodilation ... ...

    Abstract Asthma is characterized by airway remodeling and hyperreactivity. Our earlier studies determined that the Nitric Oxide (NO)-soluble Guanylyl Cyclase (sGC)-cGMP pathway plays a significant role in human lung bronchodilation. However this bronchodilation is dysfunctional in asthma due to high NO levels which cause sGC to become heme-free and desensitized to its natural activator, NO. In order to determine how asthma impacts the various lung segments/lobes we mapped the inflammatory regions of lungs to determine whether such regions coincided with molecular signatures of sGC dysfunction. We demonstrate using models of mouse asthma (OVA, CFA/HDM) that the inflammed segments of the mouse asthma lungs can be tracked by upregulated expression of HO1 and these regions in-turn overlap with regions of heme-free sGC as evidenced by a decreased sGC-α1β1 heterodimer and an increased response to heme-independent sGC activator, BAY 60-2770 relative to naïve uninflamed regions. We also find that NO generated from iNOS upregulation in the inflamed segments has a higher impact in developing heme-free sGC as increasing iNOS activity correlates linearly with elevated heme-independent sGC activation. This excess NO works by affecting the epithelial lung hemoglobin (Hb) to become heme-free in asthma thereby causing the Hb to lose its NO scavenging function and exposing the underlying smooth muscle sGC to excess NO, which in-turn becomes heme-free. Recognition of these specific lung segments enhance our understanding of the inflammed lungs in asthma with the ultimate aim to evaluate potential therapies and suggests that regional and not global inflammation impacts lung function in asthma.
    Language English
    Publishing date 2023-12-01
    Publishing country United States
    Document type Preprint
    DOI 10.1101/2023.11.29.569245
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

To top