1
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Karnam S, Maurya S, Ng E, Choudhary A, Thobani A, Flanagan JG, Gronert K. Dysregulation of neuroprotective lipoxin pathway in astrocytes in response to cytokines and ocular hypertension. Acta Neuropathol Commun 2024; 12:58. [PMID: 38610040 PMCID: PMC11010376 DOI: 10.1186/s40478-024-01767-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Accepted: 03/27/2024] [Indexed: 04/14/2024] Open
Abstract
Glaucoma leads to vision loss due to retinal ganglion cell death. Astrocyte reactivity contributes to neurodegeneration. Our recent study found that lipoxin B4 (LXB4), produced by retinal astrocytes, has direct neuroprotective actions on retinal ganglion cells. In this study, we aimed to investigate how the autacoid LXB4 influences astrocyte reactivity in the retina under inflammatory cytokine-induced activation and during ocular hypertension. The protective activity of LXB4 was investigated in vivo using the mouse silicone-oil model of chronic ocular hypertension. By employing a range of analytical techniques, including bulk RNA-seq, RNAscope in-situ hybridization, qPCR, and lipidomic analyses, we discovered the formation of lipoxins and expression of the lipoxin pathway in rodents (including the retina and optic nerve), primates (optic nerve), and human brain astrocytes, indicating the presence of this neuroprotective pathway across various species. Findings in the mouse retina identified significant dysregulation of the lipoxin pathway in response to chronic ocular hypertension, leading to an increase in 5-lipoxygenase (5-LOX) activity and a decrease in 15-LOX activity. This dysregulation was coincident with a marked upregulation of astrocyte reactivity. Reactive human brain astrocytes also showed a significant increase in 5-LOX. Treatment with LXB4 amplified the lipoxin biosynthetic pathway by restoring and amplifying the generation of another member of the lipoxin family, LXA4, and mitigated astrocyte reactivity in mouse retinas and human brain astrocytes. In conclusion, the lipoxin pathway is functionally expressed in rodents, primates, and human astrocytes, and is a resident neuroprotective pathway that is downregulated in reactive astrocytes. Novel cellular targets for LXB4's neuroprotective action are inhibition of astrocyte reactivity and restoration of lipoxin generation. Amplifying the lipoxin pathway is a potential target to disrupt or prevent astrocyte reactivity in neurodegenerative diseases, including retinal ganglion cell death in glaucoma.
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Affiliation(s)
- Shruthi Karnam
- Herbert Wertheim School of Optometry and Vision Science, University of California Berkeley, Berkeley, CA, USA
| | - Shubham Maurya
- Herbert Wertheim School of Optometry and Vision Science, University of California Berkeley, Berkeley, CA, USA
| | - Elainna Ng
- Herbert Wertheim School of Optometry and Vision Science, University of California Berkeley, Berkeley, CA, USA
| | - Amodini Choudhary
- Herbert Wertheim School of Optometry and Vision Science, University of California Berkeley, Berkeley, CA, USA
| | - Arzin Thobani
- Herbert Wertheim School of Optometry and Vision Science, University of California Berkeley, Berkeley, CA, USA
| | - John G Flanagan
- Herbert Wertheim School of Optometry and Vision Science, University of California Berkeley, Berkeley, CA, USA.
| | - Karsten Gronert
- Herbert Wertheim School of Optometry and Vision Science, University of California Berkeley, Berkeley, CA, USA.
- Infectious Disease and Immunity Program, Herbert Wertheim School of Optometry and Vision Science, University of California Berkeley, Berkeley, CA, USA.
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Maurya S, Lin M, Karnam S, Singh T, Kumar M, Ward E, Flanagan JG, Gronert K. Regulation of Diseases-Associated Microglia in the Optic Nerve by Lipoxin B 4 and Ocular Hypertension. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.18.585452. [PMID: 38562864 PMCID: PMC10983965 DOI: 10.1101/2024.03.18.585452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Background The resident astrocyte-retinal ganglion cell (RGC) lipoxin circuit is impaired during retinal stress, which includes ocular hypertension-induced neuropathy. Lipoxin B4 produced by homeostatic astrocytes directly acts on RGCs to increase survival and function in ocular hypertension-induced neuropathy. RGC death in the retina and axonal degeneration in the optic nerve are driven by the complex interactions between microglia and macroglia. Whether LXB4 neuroprotective actions include regulation of other cell types in the retina and/or optic nerve is an important knowledge gap. Methods Cellular targets and signaling of LXB4 in the retina were defined by single-cell RNA sequencing. Retinal neurodegeneration was induced by injecting silicone oil into the anterior chamber of the mouse eyes, which induced sustained and stable ocular hypertension. Morphological characterization of microglia populations in the retina and optic nerve was established by MorphOMICs and pseudotime trajectory analyses. The pathways and mechanisms of action of LXB4 in the optic nerve were investigated using bulk RNA sequencing. Transcriptomics data was validated by qPCR and immunohistochemistry. Differences between experimental groups was assessed by Student's t-test and one-way ANOVA. Results Single-cell transcriptomics identified microglia as a primary target for LXB4 in the healthy retina. LXB4 downregulated genes that drive microglia environmental sensing and reactivity responses. Analysis of microglial function revealed that ocular hypertension induced distinct, temporally defined, and dynamic phenotypes in the retina and, unexpectedly, in the distal myelinated optic nerve. Microglial expression of CD74, a marker of disease-associated microglia in the brain, was only induced in a unique population of optic nerve microglia, but not in the retina. Genetic deletion of lipoxin formation correlated with the presence of a CD74 optic nerve microglia population in normotensive eyes, while LXB4 treatment during ocular hypertension shifted optic nerve microglia toward a homeostatic morphology and non-reactive state and downregulated the expression of CD74. Furthermore, we identified a correlation between CD74 and phospho-phosphoinositide 3-kinases (p-PI3K) expression levels in the optic nerve, which was reduced by LXB4 treatment. Conclusion We identified early and dynamic changes in the microglia functional phenotype, reactivity, and induction of a unique CD74 microglia population in the distal optic nerve as key features of ocular hypertension-induced neurodegeneration. Our findings establish microglia regulation as a novel LXB4 target in the retina and optic nerve. LXB4 maintenance of a homeostatic optic nerve microglia phenotype and inhibition of a disease-associated phenotype are potential neuroprotective mechanisms for the resident LXB4 pathway.
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Affiliation(s)
- Shubham Maurya
- Herbert Wertheim School of Optometry and Vision Science, University of California, Berkeley, CA, United States
| | - Maggie Lin
- Herbert Wertheim School of Optometry and Vision Science, University of California, Berkeley, CA, United States
| | - Shruthi Karnam
- Herbert Wertheim School of Optometry and Vision Science, University of California, Berkeley, CA, United States
| | - Tanirika Singh
- Herbert Wertheim School of Optometry and Vision Science, University of California, Berkeley, CA, United States
| | - Matangi Kumar
- Herbert Wertheim School of Optometry and Vision Science, University of California, Berkeley, CA, United States
- Vision Science Program, University of California Berkeley, CA, United States
| | - Emily Ward
- Herbert Wertheim School of Optometry and Vision Science, University of California, Berkeley, CA, United States
- Vision Science Program, University of California Berkeley, CA, United States
| | - John G Flanagan
- Herbert Wertheim School of Optometry and Vision Science, University of California, Berkeley, CA, United States
- Vision Science Program, University of California Berkeley, CA, United States
| | - Karsten Gronert
- Herbert Wertheim School of Optometry and Vision Science, University of California, Berkeley, CA, United States
- Vision Science Program, University of California Berkeley, CA, United States
- Infectious Disease and Immunity Program, University of California Berkeley, CA, United States
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Liu HH, Cullen PF, Sivak JM, Gronert K, Flanagan JG. Protective Effects of Lipoxin A 4 and B 4 Signaling on the Inner Retina in a Mouse Model of Experimental Glaucoma. bioRxiv 2024:2024.01.17.575414. [PMID: 38293224 PMCID: PMC10827219 DOI: 10.1101/2024.01.17.575414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
Glaucoma is a common neurodegenerative disease characterized by progressive degeneration of retinal ganglion cells (RGCs) and the retinal nerve fiber layer (RNFL), resulting in a gradual decline of vision. A recent study by our groups indicated that the levels of lipoxins A4 (LXA4) and B4 (LXB4) in the retina and optic nerve decrease following acute injury, and that restoring their function is neuroprotective. Lipoxins are members of the specialized pro-resolving mediator (SPM) family and play key roles to mitigate and resolve chronic inflammation and tissue damage. Yet, knowledge about lipoxin neuroprotective activity remains limited. Here we investigate the in vivo efficacy of exogenous LXA4 and LXB4 administration on the inner retina in a mouse model of chronic experimental glaucoma. To investigate the contribution of LXA4 signaling we used transgenic knockout (KO) mice lacking the two mouse LXA4 receptors (Fpr2/Fpr3-/-). Functional and structural changes of inner retinal neurons were assessed longitudinally using electroretinogram (ERG) and optical coherence tomography (OCT). At the end of the experiment, retinal samples were harvested for immunohistological assessment. While both lipoxins generated protective trends, only LXB4 treatment was significant, and consistently more efficacious than LXA4 in all endpoints. Both lipoxins also appeared to dramatically reduce Müller glial reactivity following injury. In comparison, Fpr2/Fpr3 deletion significantly worsened inner retinal injury and function, consistent with an essential protective role for endogenous LXA4. Together, these results support further exploration of lipoxin signaling as a treatment for glaucomatous neurodegeneration.
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Affiliation(s)
- Hsin-Hua Liu
- Herbert Wertheim School of Optometry and Vision Science, University of California at Berkeley, Berkeley, California, United States
| | - Paul F. Cullen
- Herbert Wertheim School of Optometry and Vision Science, University of California at Berkeley, Berkeley, California, United States
| | - Jeremy M. Sivak
- Department of Ophthalmology and Vision Science, University of Toronto, Toronto, Ontario, Canada
- Krembil Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Karsten Gronert
- Herbert Wertheim School of Optometry and Vision Science, University of California at Berkeley, Berkeley, California, United States
| | - John G. Flanagan
- Herbert Wertheim School of Optometry and Vision Science, University of California at Berkeley, Berkeley, California, United States
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Livne-Bar I, Maurya S, Gronert K, Sivak JM. Lipoxins A 4 and B 4 inhibit glial cell activation via CXCR3 signaling in acute retinal neuroinflammation. J Neuroinflammation 2024; 21:18. [PMID: 38212822 PMCID: PMC10782675 DOI: 10.1186/s12974-024-03010-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 01/01/2024] [Indexed: 01/13/2024] Open
Abstract
Lipoxins are small lipids that are potent endogenous mediators of systemic inflammation resolution in a variety of diseases. We previously reported that Lipoxins A4 and B4 (LXA4 and LXB4) have protective activities against neurodegenerative injury. Yet, lipoxin activities and downstream signaling in neuroinflammatory processes are not well understood. Here, we utilized a model of posterior uveitis induced by lipopolysaccharide endotoxin (LPS), which results in rapid retinal neuroinflammation primarily characterized by activation of resident macroglia (astrocytes and Müller glia), and microglia. Using this model, we observed that each lipoxin reduces acute inner retinal inflammation by affecting endogenous glial responses in a cascading sequence beginning with astrocytes and then microglia, depending on the timing of exposure; prophylactic or therapeutic. Subsequent analyses of retinal cytokines and chemokines revealed inhibition of both CXCL9 (MIG) and CXCL10 (IP10) by each lipoxin, compared to controls, following LPS injection. CXCL9 and CXCL10 are common ligands for the CXCR3 chemokine receptor, which is prominently expressed in inner retinal astrocytes and ganglion cells. We found that CXCR3 inhibition reduces LPS-induced neuroinflammation, while CXCR3 agonism alone induces astrocyte reactivity. Together, these data uncover a novel lipoxin-CXCR3 pathway to promote distinct anti-inflammatory and proresolution cascades in endogenous retinal glia.
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Affiliation(s)
- Izhar Livne-Bar
- Department of Vision Sciences, Donald K Johnson Eye Institute, Krembil Research Institute, University Health Network, Krembil Discovery Tower, 60 Leonard Avenue, Toronto, ON, M5T 0S8, Canada
- Department of Ophthalmology and Vision Science, University of Toronto School of Medicine, Toronto, Canada
| | - Shubham Maurya
- Herbert Wertheim School of Optometry and Vision Science, University of California Berkeley, Berkeley, CA, USA
| | - Karsten Gronert
- Herbert Wertheim School of Optometry and Vision Science, University of California Berkeley, Berkeley, CA, USA
- Vision Science Program, University of California Berkeley, Berkeley, CA, USA
- Infectious Disease and Immunity Program, University of California Berkeley, Berkeley, CA, USA
| | - Jeremy M Sivak
- Department of Vision Sciences, Donald K Johnson Eye Institute, Krembil Research Institute, University Health Network, Krembil Discovery Tower, 60 Leonard Avenue, Toronto, ON, M5T 0S8, Canada.
- Department of Ophthalmology and Vision Science, University of Toronto School of Medicine, Toronto, Canada.
- Department of Laboratory Medicine and Pathobiology, University of Toronto School of Medicine, Toronto, Canada.
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5
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Karnam S, Maurya S, Ng E, Choudhary A, Thobani A, Flanagan JG, Gronert K. Dysregulation of Neuroprotective Lipoxin Pathway in Astrocytes in Response to Cytokines and Ocular Hypertension. bioRxiv 2023:2023.06.22.546157. [PMID: 37425861 PMCID: PMC10327029 DOI: 10.1101/2023.06.22.546157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
Glaucoma leads to vision loss due to retinal ganglion cell death. Astrocyte reactivity contributes to neurodegeneration. Our recent study found that lipoxin B4 (LXB4), produced by retinal astrocytes, has direct neuroprotective actions on retinal ganglion cells. In this study, we aimed to investigate how the autacoid LXB4 influences astrocyte activity in the retina under inflammatory cytokine-induced activation and during ocular hypertension. The protective activity of LXB4 was investigated in vivo using the mouse silicone-oil model of chronic ocular hypertension (n=40). By employing a range of analytical techniques, including bulk RNA-seq, RNAscope in-situ hybridization, qPCR, and lipidomic analyses, we discovered the formation of lipoxins and expression of the lipoxin pathway in rodents (including the retina and optic nerve), primates (optic nerve), and human brain astrocytes, indicating the presence of this neuroprotective pathway across various species. Findings in the mouse retina identified significant dysregulation of the lipoxin pathway in response to chronic ocular hypertension, leading to an increase in 5-lipoxygenase (5-LOX) activity and a decrease in 15-LOX activity. This dysregulation was coincident with a marked upregulation of astrocyte reactivity. Reactive human brain astrocytes also showed a significant increase in 5-LOX. Treatment with LXB4 amplified the lipoxin biosynthetic pathway by restoring and amplifying the generation of another member of the lipoxin family, LXA4, and mitigated astrocyte reactivity in mouse retinas and human brain astrocytes. In conclusion, the lipoxin pathway is functionally expressed in rodents, primates, and human astrocytes, and is a resident neuroprotective pathway that is downregulated in reactive astrocytes. Novel cellular targets for LXB4's neuroprotective action are inhibition of astrocyte reactivity and restoration of lipoxin generation. Amplifying the lipoxin pathway is a potential target to disrupt or prevent astrocyte reactivity in neurodegenerative diseases, including retinal ganglion cell death in glaucoma.
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Affiliation(s)
- Shruthi Karnam
- Herbert Wertheim School of Optometry and Vision Science, University of California Berkeley, Berkeley, California, United States
| | - Shubham Maurya
- Herbert Wertheim School of Optometry and Vision Science, University of California Berkeley, Berkeley, California, United States
| | | | - Amodini Choudhary
- Herbert Wertheim School of Optometry and Vision Science, University of California Berkeley, Berkeley, California, United States
| | - Arzin Thobani
- Herbert Wertheim School of Optometry and Vision Science, University of California Berkeley, Berkeley, California, United States
| | - John G Flanagan
- Herbert Wertheim School of Optometry and Vision Science, University of California Berkeley, Berkeley, California, United States
| | - Karsten Gronert
- Herbert Wertheim School of Optometry and Vision Science, University of California Berkeley, Berkeley, California, United States
- Infectious Disease and Immunity Program, Herbert Wertheim School of Optometry and Vision Science, University of California Berkeley, CA, United States
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6
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Gronert K, Modi A, Asfaha K, Chen S, Dow E, Joslin S, Chemaly M, Fadli Z, Sonoda L, Liang B. Silicone hydrogel contact lenses retain and document ocular surface lipid mediator profiles. Clin Exp Optom 2022:1-9. [PMID: 35658852 DOI: 10.1080/08164622.2022.2083945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
CLINICAL RELEVANCE A leading reason for patients to abandon their contact lenses is discomfort. Mechanisms and biomarkers for lens discomfort remain to be elucidated. BACKGROUND Physical stress and tear film interaction are likely factors for lens discomfort. Lipid mediators are generated from polyunsaturated fatty acids. They regulate ocular surface physiology and pathophysiology, are constituents of human tears and may interact with contact lenses. This study set out to determine if hydrogel lenses and silicone hydrogel lenses interact with tear film polyunsaturated fatty acids and polyunsaturated fatty acids-derived mediators. METHODS In vitro incubations, rat experiments and analysis of worn human lenses assessed polyunsaturated fatty acids and lipid mediator interactions with lenses. Silicone hydrogel and hydrogel lenses were incubated with lipid mediators and polyunsaturated fatty acids up to 24 hours. Rats were fitted with custom silicone hydrogel lenses and basal tears collected. Silicone hydrogel lenses worn for 2 weeks were obtained from 57 human subjects. Tear and lens lipidomes were quantified by mass spectrometry. RESULTS Silicone hydrogel lenses retained polyunsaturated fatty acids and lipid mediators within 15 minutes in vitro. Lenses contained 90% of total polyunsaturated fatty acids and 83-89% of total monohydroxy fatty acids by 12 hours. Retention correlated with polarity of lipid mediators and lipophilic properties of silicone hydrogel lenses. Polyunsaturated fatty acids and lipid mediators such as lipoxygenase- and cyclooxygenase-derived eicosanoids were present in tears and worn lenses from rats. Worn silicone hydrogel lenses from human subjects established robust and lens-type specific lipidomes with high levels of polyunsaturated fatty acids, lipoxygenase-pathway markers and subject-specific differences in lipoxin A4 and leukotriene B4. CONCLUSION Worn silicone hydrogel lenses rapidly retain and accumulate tear polyunsaturated fatty acids and lipid mediators. Marked subject and lens type differences in the lipidome may document changes in ocular surface physiology, cell activation or infection that are associated with lens wear. If contact lens discomfort and adverse events induce specific tear and lens fatty acid and lipid mediator profiles warrants further studies.
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Affiliation(s)
- Karsten Gronert
- Vision Science Program, Herbert Wertheim School of Optometry & Vision Science, Infectious Disease and Immunity Program, University of California Berkeley, Berkeley, CA, USA
| | - Arnav Modi
- Vision Science Program, Herbert Wertheim School of Optometry & Vision Science, Infectious Disease and Immunity Program, University of California Berkeley, Berkeley, CA, USA
| | - Kaleb Asfaha
- Vision Science Program, Herbert Wertheim School of Optometry & Vision Science, Infectious Disease and Immunity Program, University of California Berkeley, Berkeley, CA, USA
| | - Sharon Chen
- Vision Science Program, Herbert Wertheim School of Optometry & Vision Science, Infectious Disease and Immunity Program, University of California Berkeley, Berkeley, CA, USA
| | - Elizabeth Dow
- Advance Science and Technology, Johnson & Johnson Vision Care, Jacksonville, FL, USA
| | - Scott Joslin
- Advance Science and Technology, Johnson & Johnson Vision Care, Jacksonville, FL, USA
| | - Mike Chemaly
- Advance Science and Technology, Johnson & Johnson Vision Care, Jacksonville, FL, USA
| | - Zohra Fadli
- Advance Science and Technology, Johnson & Johnson Vision Care, Jacksonville, FL, USA
| | - Leilani Sonoda
- Advance Science and Technology, Johnson & Johnson Vision Care, Jacksonville, FL, USA
| | - Bailin Liang
- Advance Science and Technology, Johnson & Johnson Vision Care, Jacksonville, FL, USA
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Gronert K, Modi A, Asfaha K, Chen S, Dow E, Joslin S, Chemaly M, Fadli Z, Sonoda L, Liang B. Silicone Hydrogel Contact Lenses Retain and Document Ocular Surface Lipid Mediator Profiles. Cont Lens Anterior Eye 2022. [DOI: 10.1016/j.clae.2022.101673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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8
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Oyesola OO, Shanahan MT, Kanke M, Mooney BM, Webb LM, Smita S, Matheson MK, Campioli P, Pham D, Früh SP, McGinty JW, Churchill MJ, Cahoon JL, Sundaravaradan P, Flitter BA, Mouli K, Nadjsombati MS, Kamynina E, Peng SA, Cubitt RL, Gronert K, Lord JD, Rauch I, von Moltke J, Sethupathy P, Tait Wojno ED. PGD2 and CRTH2 counteract Type 2 cytokine-elicited intestinal epithelial responses during helminth infection. J Exp Med 2021; 218:e20202178. [PMID: 34283207 PMCID: PMC8294949 DOI: 10.1084/jem.20202178] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Revised: 04/28/2021] [Accepted: 06/21/2021] [Indexed: 01/22/2023] Open
Abstract
Type 2 inflammation is associated with epithelial cell responses, including goblet cell hyperplasia, that promote worm expulsion during intestinal helminth infection. How these epithelial responses are regulated remains incompletely understood. Here, we show that mice deficient in the prostaglandin D2 (PGD2) receptor CRTH2 and mice with CRTH2 deficiency only in nonhematopoietic cells exhibited enhanced worm clearance and intestinal goblet cell hyperplasia following infection with the helminth Nippostrongylus brasiliensis. Small intestinal stem, goblet, and tuft cells expressed CRTH2. CRTH2-deficient small intestinal organoids showed enhanced budding and terminal differentiation to the goblet cell lineage. During helminth infection or in organoids, PGD2 and CRTH2 down-regulated intestinal epithelial Il13ra1 expression and reversed Type 2 cytokine-mediated suppression of epithelial cell proliferation and promotion of goblet cell accumulation. These data show that the PGD2-CRTH2 pathway negatively regulates the Type 2 cytokine-driven epithelial program, revealing a mechanism that can temper the highly inflammatory effects of the anti-helminth response.
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Affiliation(s)
- Oyebola O. Oyesola
- Department of Immunology, University of Washington, Seattle, WA
- Baker Institute for Animal Health and Department of Microbiology and Immunology, Cornell University College of Veterinary Medicine, Ithaca, NY
| | - Michael T. Shanahan
- Department of Biomedical Sciences, Cornell University College of Veterinary Medicine, Ithaca, NY
| | - Matt Kanke
- Department of Biomedical Sciences, Cornell University College of Veterinary Medicine, Ithaca, NY
| | | | - Lauren M. Webb
- Department of Immunology, University of Washington, Seattle, WA
| | - Shuchi Smita
- Department of Immunology, University of Washington, Seattle, WA
| | | | - Pamela Campioli
- Baker Institute for Animal Health and Department of Microbiology and Immunology, Cornell University College of Veterinary Medicine, Ithaca, NY
| | - Duc Pham
- Baker Institute for Animal Health and Department of Microbiology and Immunology, Cornell University College of Veterinary Medicine, Ithaca, NY
| | - Simon P. Früh
- Baker Institute for Animal Health and Department of Microbiology and Immunology, Cornell University College of Veterinary Medicine, Ithaca, NY
| | - John W. McGinty
- Department of Immunology, University of Washington, Seattle, WA
| | - Madeline J. Churchill
- Department of Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, OR
| | | | | | - Becca A. Flitter
- Vision Science Program, School of Optometry, University of California, Berkeley, Berkeley, CA
| | - Karthik Mouli
- Vision Science Program, School of Optometry, University of California, Berkeley, Berkeley, CA
| | | | - Elena Kamynina
- Baker Institute for Animal Health and Department of Microbiology and Immunology, Cornell University College of Veterinary Medicine, Ithaca, NY
| | - Seth A. Peng
- Baker Institute for Animal Health and Department of Microbiology and Immunology, Cornell University College of Veterinary Medicine, Ithaca, NY
| | - Rebecca L. Cubitt
- Baker Institute for Animal Health and Department of Microbiology and Immunology, Cornell University College of Veterinary Medicine, Ithaca, NY
- Department of Biomedical Sciences, Cornell University College of Veterinary Medicine, Ithaca, NY
| | - Karsten Gronert
- Vision Science Program, School of Optometry, University of California, Berkeley, Berkeley, CA
| | - James D. Lord
- Benaroya Research Institute at Virginia Mason Medical Center, Division of Gastroenterology, Seattle, WA
| | - Isabella Rauch
- Department of Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, OR
| | | | - Praveen Sethupathy
- Department of Biomedical Sciences, Cornell University College of Veterinary Medicine, Ithaca, NY
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9
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Flitter BA, Fang X, Matthay MA, Gronert K. The potential of lipid mediator networks as ocular surface therapeutics and biomarkers. Ocul Surf 2021; 19:104-114. [PMID: 32360792 PMCID: PMC7606340 DOI: 10.1016/j.jtos.2020.04.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 04/10/2020] [Accepted: 04/12/2020] [Indexed: 01/03/2023]
Abstract
In the last twenty years an impressive body of evidence in diverse inflammatory animal disease models and human tissues, has established polyunsaturated fatty acids (PUFA) derived specialized-pro-resolving mediators (SPM), as essential mediators for controlling acute inflammation, immune responses, wound healing and for resolving acute inflammation in many non-ocular tissues. SPM pathways and receptors are highly expressed in the ocular surface where they regulate wound healing, nerve regeneration, innate immunity and sex-specific regulation of auto-immune responses. Recent evidence indicates that in the eye these resident SPM networks are important for maintaining ocular surface health and immune homeostasis. Here, we will review and discuss evidence for SPMs and other PUFA-derived mediators as important endogenous regulators, biomarkers for ocular surface health and disease and their therapeutic potential.
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Affiliation(s)
- Becca A Flitter
- School of Optometry, University of California Berkeley, Berkeley, CA, 94720, USA; Vision Science Program, University of California Berkeley, Berkeley, CA, 94720, USA
| | - Xiaohui Fang
- Department of Medicine and Anesthesia, University of California, San Francisco, CA, USA; Cardiovascular Research Institute, University of California, San Francisco, CA, USA
| | - Michael A Matthay
- Department of Medicine and Anesthesia, University of California, San Francisco, CA, USA; Cardiovascular Research Institute, University of California, San Francisco, CA, USA
| | - Karsten Gronert
- School of Optometry, University of California Berkeley, Berkeley, CA, 94720, USA; Vision Science Program, University of California Berkeley, Berkeley, CA, 94720, USA; Infectious Diseases and Immunity Program, University of California Berkeley, Berkeley, CA, 94720, USA.
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10
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Wei J, Mattapallil MJ, Horai R, Jittayasothorn Y, Modi AP, Sen HN, Gronert K, Caspi RR. A novel role for lipoxin A 4 in driving a lymph node-eye axis that controls autoimmunity to the neuroretina. eLife 2020; 9:e51102. [PMID: 32118582 PMCID: PMC7064344 DOI: 10.7554/elife.51102] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Accepted: 02/29/2020] [Indexed: 12/14/2022] Open
Abstract
The eicosanoid lipoxin A4 (LXA4) has emerging roles in lymphocyte-driven diseases. We identified reduced LXA4 levels in posterior segment uveitis patients and investigated the role of LXA4 in the pathogenesis of experimental autoimmune uveitis (EAU). Immunization for EAU with a retinal self-antigen caused selective downregulation of LXA4 in lymph nodes draining the site of immunization, while at the same time amplifying LXA4 in the inflamed target tissue. T cell effector function, migration and glycolytic responses were amplified in LXA4-deficient mice, which correlated with more severe pathology, whereas LXA4 treatment attenuated disease. In vivo deletion or supplementation of LXA4 identified modulation of CC-chemokine receptor 7 (CCR7) and sphingosine 1- phosphate receptor-1 (S1PR1) expression and glucose metabolism in CD4+ T cells as potential mechanisms for LXA4 regulation of T cell effector function and trafficking. Our results demonstrate the intrinsic lymph node LXA4 pathway as a significant checkpoint in the development and severity of adaptive immunity.
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Affiliation(s)
- Jessica Wei
- Vision Science Program, University of California, BerkeleyBerkeleyUnited States
- Laboratory of Immunology, National Eye Institute, National Institutes of HealthBethesdaUnited States
| | - Mary J Mattapallil
- Laboratory of Immunology, National Eye Institute, National Institutes of HealthBethesdaUnited States
| | - Reiko Horai
- Laboratory of Immunology, National Eye Institute, National Institutes of HealthBethesdaUnited States
| | - Yingyos Jittayasothorn
- Laboratory of Immunology, National Eye Institute, National Institutes of HealthBethesdaUnited States
| | - Arnav P Modi
- School of Optometry, University of California, BerkeleyBerkeleyUnited States
| | - H Nida Sen
- Laboratory of Immunology, National Eye Institute, National Institutes of HealthBethesdaUnited States
| | - Karsten Gronert
- Vision Science Program, University of California, BerkeleyBerkeleyUnited States
- School of Optometry, University of California, BerkeleyBerkeleyUnited States
- Infectious Disease and Immunity Program, University of California, BerkeleyBerkeleyUnited States
| | - Rachel R Caspi
- Laboratory of Immunology, National Eye Institute, National Institutes of HealthBethesdaUnited States
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11
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Kim C, Livne-Bar I, Gronert K, Sivak JM. Fair-Weather Friends: Evidence of Lipoxin Dysregulation in Neurodegeneration. Mol Nutr Food Res 2020; 64:e1801076. [PMID: 31797529 DOI: 10.1002/mnfr.201801076] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 11/12/2019] [Indexed: 12/19/2022]
Abstract
Lipoxins (LXs) are autacoids, specialized proresolving lipid mediators (SPMs) acting locally in a paracrine or autocrine fashion. They belong to a complex superfamily of dietary small polyunsaturated fatty acid (PUFA)-metabolites, which direct potent cellular responses to resolve inflammation and restore tissue homeostasis. Together, these SPM activities have been intensely studied in systemic inflammation and acute injury or infection, but less is known about LX signaling and activities in the central nervous system. LXs are derived from arachidonic acid, an omega-6 PUFA. In addition to well-established roles in systemic inflammation resolution, they have increasingly become implicated in regulating neuroinflammatory and neurodegenerative processes. In particular, chronic inflammation plays a central role in Alzheimer's disease (AD) etiology, and dysregulated LX production and activities have been reported in a variety of AD rodent models and clinical tissue samples, yet with complex and sometimes conflicting results. In addition, reduced LX production following retinal injury has been reported recently by the authors, and an intriguing direct neuronal activity promoting survival and homeostasis in retinal and cortical neurons is demonstrated. Here, the authors review and clarify this growing literature and suggest new research directions to further elaborate the role of lipoxins in neurodegeneration.
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Affiliation(s)
- Changmo Kim
- Department of Laboratory Medicine and Pathobiology, University of Toronto School of Medicine, Toronto, ON, M5S 1A8, Canada
- Department of Ophthalmology and Vision Sciences, University of Toronto School of Medicine, Toronto, ON, M5S 1A8, Canada
- Krembil Research Institute, University Health Network, 60 Leonard Ave, Toronto, ON, M5T 0S8, Canada
| | - Izhar Livne-Bar
- Department of Laboratory Medicine and Pathobiology, University of Toronto School of Medicine, Toronto, ON, M5S 1A8, Canada
- Department of Ophthalmology and Vision Sciences, University of Toronto School of Medicine, Toronto, ON, M5S 1A8, Canada
- Krembil Research Institute, University Health Network, 60 Leonard Ave, Toronto, ON, M5T 0S8, Canada
| | - Karsten Gronert
- School of Optometry, Vision Science Program, University of California Berkeley, Berkeley, CA, 94720
- Infectious Disease and Immunity, University of California Berkeley, Berkeley, CA, 94720
| | - Jeremy M Sivak
- Department of Laboratory Medicine and Pathobiology, University of Toronto School of Medicine, Toronto, ON, M5S 1A8, Canada
- Department of Ophthalmology and Vision Sciences, University of Toronto School of Medicine, Toronto, ON, M5S 1A8, Canada
- Krembil Research Institute, University Health Network, 60 Leonard Ave, Toronto, ON, M5T 0S8, Canada
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12
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Walsh CM, Hill RZ, Schwendinger-Schreck J, Deguine J, Brock EC, Kucirek N, Rifi Z, Wei J, Gronert K, Brem RB, Barton GM, Bautista DM. Neutrophils promote CXCR3-dependent itch in the development of atopic dermatitis. eLife 2019; 8:48448. [PMID: 31631836 PMCID: PMC6884397 DOI: 10.7554/elife.48448] [Citation(s) in RCA: 84] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 10/17/2019] [Indexed: 12/12/2022] Open
Abstract
Chronic itch remains a highly prevalent disorder with limited treatment options. Most chronic itch diseases are thought to be driven by both the nervous and immune systems, but the fundamental molecular and cellular interactions that trigger the development of itch and the acute-to-chronic itch transition remain unknown. Here, we show that skin-infiltrating neutrophils are key initiators of itch in atopic dermatitis, the most prevalent chronic itch disorder. Neutrophil depletion significantly attenuated itch-evoked scratching in a mouse model of atopic dermatitis. Neutrophils were also required for several key hallmarks of chronic itch, including skin hyperinnervation, enhanced expression of itch signaling molecules, and upregulation of inflammatory cytokines, activity-induced genes, and markers of neuropathic itch. Finally, we demonstrate that neutrophils are required for induction of CXCL10, a ligand of the CXCR3 receptor that promotes itch via activation of sensory neurons, and we find that that CXCR3 antagonism attenuates chronic itch. Chronic itch is a debilitating disorder that can last for months or years. Eczema, or atopic dermatitis, is the most common cause for chronic itch, affecting one in ten people worldwide. Many treatments for the condition are ineffective, and the exact cause of the disease is unknown, but many different types of cells are likely involved. These include skin cells and inflammation-promoting immune cells, as well as nerve cells that detect inflammation, relay itch and pain information to the brain, and regulate the immune system. Learning more about how these cells interact in eczema may help scientists find better treatments for the condition. So far, a lot of research has focused on static ‘snapshots’ of mature eczema lesions from human skin or animal models. These studies have identified abnormalities in genes or cells, but have not revealed how these genes and cells interact over time to cause chronic itch and inflammation. Now, Walsh et al. reveal that immune cells called neutrophils trigger chronic itch in eczema. The experiments involved mice with a condition that mimics eczema, and showed that removing the neutrophils in these mice alleviated their itching. They also showed that dramatic and rapid changes occur in the nervous system of mice suffering from the eczema-like condition. For example, excess nerves grow in the animals’ damaged skin, genes in the nerves that detect sensations become hyperactive, and changes occur in the spinal cord that have been linked to nerve pain. When neutrophils are absent, these changes do not take place. These findings show that neutrophils play a key role in chronic itch and inflammation in eczema. Drugs that target neutrophils, which are already used to treat other diseases, might help with chronic itch, but they would need to be tested before they can be used on people with eczema.
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Affiliation(s)
- Carolyn M Walsh
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Rose Z Hill
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | | | - Jacques Deguine
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Emily C Brock
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Natalie Kucirek
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Ziad Rifi
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Jessica Wei
- Vision Science Program, School of Optometry, University of California, Berkeley, Berkeley, United States
| | - Karsten Gronert
- Vision Science Program, School of Optometry, University of California, Berkeley, Berkeley, United States
| | - Rachel B Brem
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, United States.,Buck Institute for Research on Aging, Novato, United States
| | - Gregory M Barton
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Diana M Bautista
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States.,Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, United States
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13
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Wei J, Gronert K. Eicosanoid and Specialized Proresolving Mediator Regulation of Lymphoid Cells. Trends Biochem Sci 2018; 44:214-225. [PMID: 30477730 DOI: 10.1016/j.tibs.2018.10.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Revised: 10/19/2018] [Accepted: 10/20/2018] [Indexed: 12/12/2022]
Abstract
Eicosanoids and specialized proresolving mediators (SPMs) regulate leukocyte function and inflammation. They are ideally positioned at the interface of the innate and adaptive immune responses when lymphocytes interact with leukocytes. Receptors for leukotriene B4 (LTB4), prostaglandin E2 (PGE2), and SPMs are expressed on lymphocytes. Evidence points toward an essential role of these lipid mediators (LMs) in direct regulation of lymphocyte functions. SPMs, which include lipoxins, demonstrate comprehensive protective actions with lymphocytes. LTB4 and PGE2 regulation of lymphocytes is diverse and depends on the interaction of lymphocytes with other cells. Importantly, both LTB4 and PGE2 are essential regulators of T cell antitumor activity. These LMs are attractive therapeutic targets to control dysregulated innate and adaptive immune responses, promote lymphocyte antitumor activity, and prevent tumor immune evasion.
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Affiliation(s)
- Jessica Wei
- Vision Science Program, School of Optometry, Infectious Disease and Immunity Program, University of California Berkeley, Berkeley, CA 94720, USA
| | - Karsten Gronert
- Vision Science Program, School of Optometry, Infectious Disease and Immunity Program, University of California Berkeley, Berkeley, CA 94720, USA.
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14
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Gao Y, Su J, Zhang Y, Chan A, Sin JH, Wu D, Min K, Gronert K. Dietary DHA amplifies LXA 4 circuits in tissues and lymph node PMN and is protective in immune-driven dry eye disease. Mucosal Immunol 2018; 11:1674-1683. [PMID: 30104626 PMCID: PMC6279588 DOI: 10.1038/s41385-018-0070-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 07/02/2018] [Accepted: 07/10/2018] [Indexed: 02/04/2023]
Abstract
Recently identified regulatory PMN control immune-driven dry eye disease (DED) in females by producing the arachidonic acid (ω-6)-derived specialized pro-resolving mediator (SPM), LXA4, in lymph nodes. Dietary ω-3 docosahexaenoic acid (DHA) is protective in DED but mechanisms of action remain elusive. DHA is converted to ω-3 SPMs by PMN via the same lipoxygenases (LOX) that generate LXA4. We investigated if dietary DHA amplifies SPM formation and affects T effector cell function and/or regulatory PMN in DED. DED was induced in mice on a DHA-enriched or ω-3-deficient diet. DHA deficiency amplified DED with marked sex-specific differences. Dietary DHA protection against dry eye disease correlated with increased PMN levels in lymph nodes, ocular tissues, and unexpectedly, selective amplification of LXA4 tissue levels. Dietary DHA increased 12/15-LOX and decreased 5-LOX expression in lymph nodes and isolated lymph node PMN, which correlated with amplified LXA4 formation. Acute DHA treatment rescued DHA-deficient females from exaggerated DED by amplifying lymph node LXA4 formation, increasing Treg and decreasing TH1 and TH17 effector cells. Our results identify DHA regulation of LXA4 producing PMN in ocular tissues and lymph nodes in health and immune disease as novel mechanism and determinant for T-cell responses to routine ocular injury or stress signals.
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Affiliation(s)
- Yuan Gao
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University, Chongqing 400038, China.,Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing 400038, China.,Vision Science Program, University of California Berkeley, Berkeley, CA 94720,School of Optometry, University of California Berkeley, Berkeley, CA 94720
| | - John Su
- Vision Science Program, University of California Berkeley, Berkeley, CA 94720
| | - Yibing Zhang
- Vision Science Program, University of California Berkeley, Berkeley, CA 94720
| | - Allison Chan
- Vision Science Program, University of California Berkeley, Berkeley, CA 94720
| | - Jun Hyung Sin
- Vision Science Program, University of California Berkeley, Berkeley, CA 94720
| | - Di Wu
- Vision Science Program, University of California Berkeley, Berkeley, CA 94720
| | - Kyungi Min
- Vision Science Program, University of California Berkeley, Berkeley, CA 94720
| | - Karsten Gronert
- Vision Science Program, University of California Berkeley, Berkeley, CA 94720,School of Optometry, University of California Berkeley, Berkeley, CA 94720,Infectious Disease and Immunity Program, University of California Berkeley, Berkeley, CA 94720
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15
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Carion TW, Greenwood M, Ebrahim AS, Jerome A, Suvas S, Gronert K, Berger EA. Immunoregulatory role of 15-lipoxygenase in the pathogenesis of bacterial keratitis. FASEB J 2018; 32:5026-5038. [PMID: 29913556 PMCID: PMC6103176 DOI: 10.1096/fj.201701502r] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Although autacoids primarily derived from the cyclooxygenase-2 and 5-lipoxygenase (LOX) pathways are essential mediators of inflammation, endogenous specialized proresolving mediators (SPMs) act as robust agonists of resolution. SPM biosynthesis is initiated by the conversion of arachidonic acid, eicosapentaenoic acid, and docosahexaenoic acid primarily via the 12/15-LOX pathway. Although 12/15-LOX activity is prominent in the cornea, the role of SPM pathway activation during infection remains largely unknown and is the focus of the current study. Pseudomonas keratitis was induced in resistant BALB/c and susceptible C57BL/6 (B6) mice. Biosynthetic pathways for proinflammatory autacoids and SPMs were assessed. Divergent lipid mediator profiles demonstrate the importance of 15-LOX pathways in the pathogenesis of ocular infectious disease. Results indicate that an imbalance of LOX enzymatic pathways contributes to susceptibility observed in B6 mice where deficient activation of SPM circuits, as indicated by reduced 15-hydroxy-eicosatetraenoic acid and 17-hydroxydocosahexaenoic acid levels, prevented transition toward resolution and led to chronic inflammation. In sharp contrast, BALB/c mice demonstrated a well-balanced axis of 5-LOX/12-LOX/15-LOX pathways, resulting in sufficient proresolving bioactive metabolite formation and immune homeostasis. Furthermore, a novel immunoregulatory role for 15-LOX was revealed in inflammatory cells (polymorphonuclear leukocytes and macrophages), which influenced phagocytic activity. These data provide evidence that SPM circuits are essential for host defense during bacterial keratitis.-Carion, T. W., Greenwood, M., Ebrahim, A. S., Jerome, A., Suvas, S., Gronert, K., Berger, E. A. Immunoregulatory role of 15-lipoxygenase in the pathogenesis of bacterial keratitis.
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Affiliation(s)
- Thomas W. Carion
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Matthew Greenwood
- School of Optometry, University of California, Berkeley, Berkeley, California, USA
| | - Abdul Shukkur Ebrahim
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Andrew Jerome
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Susmit Suvas
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, USA;,Department of Ophthalmology, Kresge Eye Institute, Detroit, Michigan, USA; and,Department of Immunology and Microbiology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Karsten Gronert
- School of Optometry, University of California, Berkeley, Berkeley, California, USA
| | - Elizabeth A. Berger
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, USA;,Department of Ophthalmology, Kresge Eye Institute, Detroit, Michigan, USA; and,Correspondence: Department of Anatomy and Cell Biology, Wayne State University School of Medicine, 540 E. Canfield Ave., 8263 Scott Hall, Detroit, MI 48201, USA. E-mail:
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16
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Knight M, Braverman J, Asfaha K, Gronert K, Stanley S. Lipid droplet formation in Mycobacterium tuberculosis infected macrophages requires IFN-γ/HIF-1α signaling and supports host defense. PLoS Pathog 2018; 14:e1006874. [PMID: 29370315 PMCID: PMC5800697 DOI: 10.1371/journal.ppat.1006874] [Citation(s) in RCA: 127] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 02/06/2018] [Accepted: 01/10/2018] [Indexed: 12/25/2022] Open
Abstract
Lipid droplet (LD) formation occurs during infection of macrophages with numerous intracellular pathogens, including Mycobacterium tuberculosis. It is believed that M. tuberculosis and other bacteria specifically provoke LD formation as a pathogenic strategy in order to create a depot of host lipids for use as a carbon source to fuel intracellular growth. Here we show that LD formation is not a bacterially driven process during M. tuberculosis infection, but rather occurs as a result of immune activation of macrophages as part of a host defense mechanism. We show that an IFN-γ driven, HIF-1α dependent signaling pathway, previously implicated in host defense, redistributes macrophage lipids into LDs. Furthermore, we show that M. tuberculosis is able to acquire host lipids in the absence of LDs, but not in the presence of IFN-γ induced LDs. This result uncouples macrophage LD formation from bacterial acquisition of host lipids. In addition, we show that IFN-γ driven LD formation supports the production of host protective eicosanoids including PGE2 and LXB4. Finally, we demonstrate that HIF-1α and its target gene Hig2 are required for the majority of LD formation in the lungs of mice infected with M. tuberculosis, thus demonstrating that immune activation provides the primary stimulus for LD formation in vivo. Taken together our data demonstrate that macrophage LD formation is a host-driven component of the adaptive immune response to M. tuberculosis, and suggest that macrophage LDs are not an important source of nutrients for M. tuberculosis.
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Affiliation(s)
- Matthew Knight
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, California, United States of America
| | - Jonathan Braverman
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Kaleb Asfaha
- Vision Science Program, School of Optometry, University of California, Berkeley, Berkeley, California, United States of America
| | - Karsten Gronert
- Vision Science Program, School of Optometry, University of California, Berkeley, Berkeley, California, United States of America
| | - Sarah Stanley
- Department of Molecular and Cell Biology, Division of Immunology and Pathogenesis, University of California, Berkeley, Berkeley, California, United States of America
- School of Public Health, Division of Infectious Diseases and Vaccinology, University of California, Berkeley, Berkeley, California, United States of America
- * E-mail:
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17
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Livne-Bar I, Wei J, Liu HH, Alqawlaq S, Won GJ, Tuccitto A, Gronert K, Flanagan JG, Sivak JM. Astrocyte-derived lipoxins A4 and B4 promote neuroprotection from acute and chronic injury. J Clin Invest 2017; 127:4403-4414. [PMID: 29106385 DOI: 10.1172/jci77398] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 09/26/2017] [Indexed: 12/31/2022] Open
Abstract
Astrocytes perform critical non-cell autonomous roles following CNS injury that involve either neurotoxic or neuroprotective effects. Yet the nature of potential prosurvival cues has remained unclear. In the current study, we utilized the close interaction between astrocytes and retinal ganglion cells (RGCs) in the eye to characterize a secreted neuroprotective signal present in retinal astrocyte conditioned medium (ACM). Rather than a conventional peptide neurotrophic factor, we identified a prominent lipid component of the neuroprotective signal through metabolomics screening. The lipoxins LXA4 and LXB4 are small lipid mediators that act locally to dampen inflammation, but they have not been linked directly to neuronal actions. Here, we determined that LXA4 and LXB4 are synthesized in the inner retina, but their levels are reduced following injury. Injection of either lipoxin was sufficient for neuroprotection following acute injury, while inhibition of key lipoxin pathway components exacerbated injury-induced damage. Although LXA4 signaling has been extensively investigated, LXB4, the less studied lipoxin, emerged to be more potent in protection. Moreover, LXB4 neuroprotection was different from that of established LXA4 signaling, and therapeutic LXB4 treatment was efficacious in a chronic model of the common neurodegenerative disease glaucoma. Together, these results identify a potential paracrine mechanism that coordinates neuronal homeostasis and inflammation in the CNS.
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Affiliation(s)
- Izhar Livne-Bar
- Department of Vision Sciences, Krembil Research Institute, University Health Network, Toronto, Ontario, Canada.,Department of Ophthalmology and Vision Science, University of Toronto, Toronto, Ontario, Canada
| | - Jessica Wei
- Vision Science Program, School of Optometry, University of California at Berkeley, Berkeley, California, USA
| | - Hsin-Hua Liu
- Vision Science Program, School of Optometry, University of California at Berkeley, Berkeley, California, USA
| | - Samih Alqawlaq
- Department of Vision Sciences, Krembil Research Institute, University Health Network, Toronto, Ontario, Canada.,Department of Ophthalmology and Vision Science, University of Toronto, Toronto, Ontario, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Gah-Jone Won
- Department of Vision Sciences, Krembil Research Institute, University Health Network, Toronto, Ontario, Canada.,Department of Ophthalmology and Vision Science, University of Toronto, Toronto, Ontario, Canada
| | - Alessandra Tuccitto
- Department of Vision Sciences, Krembil Research Institute, University Health Network, Toronto, Ontario, Canada.,Department of Ophthalmology and Vision Science, University of Toronto, Toronto, Ontario, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Karsten Gronert
- Vision Science Program, School of Optometry, University of California at Berkeley, Berkeley, California, USA
| | - John G Flanagan
- Vision Science Program, School of Optometry, University of California at Berkeley, Berkeley, California, USA
| | - Jeremy M Sivak
- Department of Vision Sciences, Krembil Research Institute, University Health Network, Toronto, Ontario, Canada.,Department of Ophthalmology and Vision Science, University of Toronto, Toronto, Ontario, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
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18
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Pazos MA, Lanter BB, Yonker LM, Eaton AD, Pirzai W, Gronert K, Bonventre JV, Hurley BP. Pseudomonas aeruginosa ExoU augments neutrophil transepithelial migration. PLoS Pathog 2017; 13:e1006548. [PMID: 28771621 PMCID: PMC5557605 DOI: 10.1371/journal.ppat.1006548] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 08/15/2017] [Accepted: 07/22/2017] [Indexed: 12/21/2022] Open
Abstract
Excessive neutrophil infiltration of the lungs is a common contributor to immune-related pathology in many pulmonary disease states. In response to pathogenic infection, airway epithelial cells produce hepoxilin A3 (HXA3), initiating neutrophil transepithelial migration. Migrated neutrophils amplify this recruitment by producing a secondary gradient of leukotriene B4 (LTB4). We sought to determine whether this two-step eicosanoid chemoattractant mechanism could be exploited by the pathogen Pseudomonas aeruginosa. ExoU, a P. aeruginosa cytotoxin, exhibits phospholipase A2 (PLA2) activity in eukaryotic hosts, an enzyme critical for generation of certain eicosanoids. Using in vitro and in vivo models of neutrophil transepithelial migration, we evaluated the impact of ExoU expression on eicosanoid generation and function. We conclude that ExoU, by virtue of its PLA2 activity, augments and compensates for endogenous host neutrophil cPLA2α function, leading to enhanced transepithelial migration. This suggests that ExoU expression in P. aeruginosa can circumvent immune regulation at key signaling checkpoints in the neutrophil, resulting in exacerbated neutrophil recruitment. Pseudomonas aeruginosa is an opportunistic pathogen that causes acute pneumonia in immune compromised patients, and infects 70–80% of patients suffering from cystic fibrosis. Infections can result in excessive airway inflammation, which lead to immune-mediated lung damage, in particular through the action of recruited white blood cells known as neutrophils. Certain strains of P. aeruginosa produce the exotoxin ExoU, which has been associated with increased virulence. ExoU causes host cell lysis by hydrolyzing host membrane lipids through its phospholipase activity. However, host phospholipases play a key role in immune signaling by mediating the production of lipids known as eicosanoids. We investigated whether separate from its cytolytic activity, ExoU could modulate host immune responses through its phospholipase activity by hijacking eicosanoid production. Using in vitro and in vivo models of neutrophil recruitment, we find that ExoU producing strains of P. aeruginosa elicit higher levels of the eicosanoid chemoattractant leukotriene B4 from migrated neutrophils. This results in increased neutrophil transepithelial migration. This work reveals a new mechanism for how bacterial pathogens alter our immune function, and highlights a new potential therapeutic strategy for moderating Pseudomonas pathogenesis in patients with cystic fibrosis and acute pneumonia.
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Affiliation(s)
- Michael A. Pazos
- Mucosal Immunology & Biology Research Center, Massachusetts General Hospital for Children, Boston, Massachusetts, United States of America
- Pediatrics, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Bernard B. Lanter
- Mucosal Immunology & Biology Research Center, Massachusetts General Hospital for Children, Boston, Massachusetts, United States of America
- Pediatrics, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Lael M. Yonker
- Mucosal Immunology & Biology Research Center, Massachusetts General Hospital for Children, Boston, Massachusetts, United States of America
- Pediatrics, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Alex D. Eaton
- Mucosal Immunology & Biology Research Center, Massachusetts General Hospital for Children, Boston, Massachusetts, United States of America
| | - Waheed Pirzai
- Mucosal Immunology & Biology Research Center, Massachusetts General Hospital for Children, Boston, Massachusetts, United States of America
| | - Karsten Gronert
- Vision Science Program, School of Optometry, University of California at Berkeley, Berkeley, California, United States of America
| | - Joseph V. Bonventre
- Renal Division and Biomedical Engineering Division, Brigham and Women's Hospital, Department of Medicine, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Bryan P. Hurley
- Mucosal Immunology & Biology Research Center, Massachusetts General Hospital for Children, Boston, Massachusetts, United States of America
- Pediatrics, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
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19
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Walter SD, Gronert K, McClellan AL, Levitt RC, Sarantopoulos KD, Galor A. ω-3 Tear Film Lipids Correlate With Clinical Measures of Dry Eye. Invest Ophthalmol Vis Sci 2017; 57:2472-8. [PMID: 27138739 PMCID: PMC4857833 DOI: 10.1167/iovs.16-19131] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
PURPOSE ω-3 and ω-6 polyunsaturated fatty acids modulate inflammatory processes throughout the body through distinct classes of lipid mediators that possess both proinflammatory and proresolving properties. The purpose of this cross-sectional study was to explore the relationship between lipid profiles in human tears and dry eye (DE) symptoms and signs. METHODS Forty-one patients with normal eyelid and corneal anatomy were prospectively recruited from a Veterans Administration Hospital over 18 months. Symptoms and signs of DE were assessed, and tear samples was analyzed by mass spectrometry-based lipidomics. Statistical analyses comparing the relationship between tear film lipids and DE included Pearson/Spearman correlations and t-tests. RESULTS Arachidonic acid (AA), docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA) were present in more than 90% of tear film samples. The ratio of ω-6 (AA) to ω-3 (DHA+EPA) fatty acids was correlated with multiple measures of tear film dysfunction (tear breakup time, Schirmer 2 scores, and corneal staining; all P < 0.05). Arachidonic acid-derived prostaglandin E2 was detected in the majority of samples and correlated with low tear osmolarity, meibomian gland plugging, and corneal staining. CONCLUSIONS Both ω-3 and ω-6 lipid circuits are activated in the human tear film. The ratio of ω-6:ω-3 tear lipids is elevated in DE patients in proportion to the degree of tear film dysfunction and corneal staining. Metabolic deficiency of ω-3 tear film lipids may be a driver of chronic ocular surface inflammation in DE.
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Affiliation(s)
- Scott D Walter
- Bascom Palmer Eye Institute, Department of Opthamology, University of Miami, Miami, Florida, United States
| | - Karsten Gronert
- School of Optometry, University of California, Berkeley, California, United States
| | - Allison L McClellan
- Department of Surgical Services, Miami Veterans Administration Medical Center, Miami, Florida, United States
| | - Roy C Levitt
- Department of Anesthesiology, Miami Veterans Administration Medical Center, Miami, Florida, United States 5John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, Florida, United States 6John T Macdonald Foundat
| | - Konstantinos D Sarantopoulos
- Department of Anesthesiology, Miami Veterans Administration Medical Center, Miami, Florida, United States 6John T Macdonald Foundation Department of Human Genetics, University of Miami Miller School of Medicine, Miami, Florida, United States
| | - Anat Galor
- Bascom Palmer Eye Institute, Department of Opthamology, University of Miami, Miami, Florida, United States 3Department of Surgical Services, Miami Veterans Administration Medical Center, Miami, Florida, United States
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20
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Rauch I, Deets KA, Ji DX, von Moltke J, Tenthorey JL, Lee AY, Philip NH, Ayres JS, Brodsky IE, Gronert K, Vance RE. NAIP-NLRC4 Inflammasomes Coordinate Intestinal Epithelial Cell Expulsion with Eicosanoid and IL-18 Release via Activation of Caspase-1 and -8. Immunity 2017; 46:649-659. [PMID: 28410991 PMCID: PMC5476318 DOI: 10.1016/j.immuni.2017.03.016] [Citation(s) in RCA: 257] [Impact Index Per Article: 36.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 12/09/2016] [Accepted: 03/24/2017] [Indexed: 11/25/2022]
Abstract
Intestinal epithelial cells (IECs) form a critical barrier against pathogen invasion. By generation of mice in which inflammasome expression is restricted to IECs, we describe a coordinated epithelium-intrinsic inflammasome response in vivo. This response was sufficient to protect against Salmonella tissue invasion and involved a previously reported IEC expulsion that was coordinated with lipid mediator and cytokine production and lytic IEC death. Excessive inflammasome activation in IECs was sufficient to result in diarrhea and pathology. Experiments with IEC organoids demonstrated that IEC expulsion did not require other cell types. IEC expulsion was accompanied by a major actin rearrangement in neighboring cells that maintained epithelium integrity but did not absolutely require Caspase-1 or Gasdermin D. Analysis of Casp1-/-Casp8-/- mice revealed a functional Caspase-8 inflammasome in vivo. Thus, a coordinated IEC-intrinsic, Caspase-1 and -8 inflammasome response plays a key role in intestinal immune defense and pathology.
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Affiliation(s)
- Isabella Rauch
- Division of Immunology & Pathogenesis, Department of Molecular & Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Katherine A Deets
- Division of Immunology & Pathogenesis, Department of Molecular & Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Daisy X Ji
- Division of Immunology & Pathogenesis, Department of Molecular & Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Jakob von Moltke
- Division of Immunology & Pathogenesis, Department of Molecular & Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Jeannette L Tenthorey
- Division of Immunology & Pathogenesis, Department of Molecular & Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Angus Y Lee
- Cancer Research Laboratory and Immunotherapeutics and Vaccine Research Initiative, University of California, Berkeley, CA 94720, USA
| | - Naomi H Philip
- Department of Pathobiology, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA 19104, USA
| | - Janelle S Ayres
- Division of Immunology & Pathogenesis, Department of Molecular & Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Igor E Brodsky
- Department of Pathobiology, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA 19104, USA
| | - Karsten Gronert
- Vision Science Program, School of Optometry, University of California at Berkeley, Berkeley, CA 94720, USA
| | - Russell E Vance
- Division of Immunology & Pathogenesis, Department of Molecular & Cell Biology, University of California, Berkeley, CA 94720, USA; Howard Hughes Medical Institute, University of California, Berkeley, CA 94720, USA; Cancer Research Laboratory and Immunotherapeutics and Vaccine Research Initiative, University of California, Berkeley, CA 94720, USA.
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21
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Wei J, Gronert K. The role of pro-resolving lipid mediators in ocular diseases. Mol Aspects Med 2017; 58:37-43. [PMID: 28366638 DOI: 10.1016/j.mam.2017.03.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 03/23/2017] [Accepted: 03/27/2017] [Indexed: 02/03/2023]
Affiliation(s)
- Jessica Wei
- Vision Science Graduate Program, University of California Berkeley, Berkeley, CA 94720, United States
| | - Karsten Gronert
- Vision Science Graduate Program, University of California Berkeley, Berkeley, CA 94720, United States; School of Optometry, University of California Berkeley, Berkeley, CA 94720, United States; Infectious Disease and Immunity Graduate Program, University of California Berkeley, Berkeley, CA 94720, United States.
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22
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Deguine J, Wei J, Barbalat R, Gronert K, Barton GM. Local TNFR1 Signaling Licenses Murine Neutrophils for Increased TLR-Dependent Cytokine and Eicosanoid Production. J Immunol 2017; 198:2865-2875. [PMID: 28219890 DOI: 10.4049/jimmunol.1601465] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 01/24/2017] [Indexed: 01/01/2023]
Abstract
Neutrophils are generally the first immune cells recruited during the development of sterile or microbial inflammation. As these cells express many innate immune receptors with the potential to directly recognize microbial or endogenous signals, we set out to assess whether their functions are locally influenced by the signals present at the onset of inflammation. Using a mouse model of peritonitis, we demonstrate that neutrophils elicited in the presence of C-type lectin receptor ligands have an increased ability to produce cytokines, chemokines, and lipid mediators in response to subsequent TLR stimulation. Importantly, we found that licensing of cytokine production was mediated by paracrine TNF-α-TNFR1 signaling rather than direct ligand sensing, suggesting a form of quorum sensing among neutrophils. Mechanistically, licensing was largely imparted by changes in the posttranscriptional regulation of inflammatory cytokines, whereas production of IL-10 was regulated at the transcriptional level. Altogether, our data suggest that neutrophils rapidly adapt their functions to the local inflammatory milieu. These phenotypic changes may promote rapid neutrophil recruitment in the presence of pathogens but limit inflammation in their absence.
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Affiliation(s)
- Jacques Deguine
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA 94720; and
| | - Jessica Wei
- Vision Science Program, School of Optometry, University of California Berkeley, Berkeley, CA 94598
| | - Roman Barbalat
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA 94720; and
| | - Karsten Gronert
- Vision Science Program, School of Optometry, University of California Berkeley, Berkeley, CA 94598
| | - Gregory M Barton
- Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA 94720; and
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23
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Mozurkewich EL, Greenwood M, Clinton C, Berman D, Romero V, Djuric Z, Qualls C, Gronert K. Pathway Markers for Pro-resolving Lipid Mediators in Maternal and Umbilical Cord Blood: A Secondary Analysis of the Mothers, Omega-3, and Mental Health Study. Front Pharmacol 2016; 7:274. [PMID: 27656142 PMCID: PMC5013256 DOI: 10.3389/fphar.2016.00274] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 08/11/2016] [Indexed: 12/13/2022] Open
Abstract
The omega-3 fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are precursors to immune regulatory and specialized pro-resolving mediators (SPM) of inflammation termed resolvins, maresins, and protectins. Evidence for lipid mediator formation in vivo can be gained through evaluation of their 5-lipoxygenase (LOX) and 15-LOX metabolic pathway precursors and downstream metabolites. We performed a secondary blood sample analysis from 60 participants in the Mothers, Omega-3, and Mental Health study to determine whether SPM and SPM precursors are augmented by dietary EPA- and DHA-rich fish oil supplementation compared to soy oil placebo. We also aimed to study whether SPM and their precursors differ in early and late pregnancy or between maternal and umbilical cord blood. We found that compared to placebo supplementation, EPA- and DHA-rich fish oil supplementation increased SPM precursor 17-hydroxy docosahexaenoic acid (17-HDHA) concentrations in maternal and umbilical cord blood (P = 0.02). We found that the D-series resolvin pathway marker 17-HDHA increased significantly between enrollment and late pregnancy (P = 0.049). Levels of both 14-HDHA, a maresin pathway marker, and 17-HDHA were significantly greater in umbilical cord blood than in maternal blood (P < 0.001, both).
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Affiliation(s)
- Ellen L Mozurkewich
- Obstetrics and Gynecology, University of New MexicoAlbuquerque, NM, USA; Obstetrics and Gynecology, University of MichiganAnn Arbor, MI, USA
| | - Matthew Greenwood
- Vision Science Program, Infectious Diseases and Immunity Program, School of Optometry, University of California at Berkeley Berkeley, CA, USA
| | | | - Deborah Berman
- Obstetrics and Gynecology, University of Michigan Ann Arbor, MI, USA
| | - Vivian Romero
- Obstetrics and Gynecology, Michigan State University Grand Rapids, MI, USA
| | - Zora Djuric
- Family Medicine, University of Michigan Ann Arbor, MI, USA
| | - Clifford Qualls
- Clinical and Translational Sciences Center, University of New Mexico Albuquerque, NM, USA
| | - Karsten Gronert
- Vision Science Program, Infectious Diseases and Immunity Program, School of Optometry, University of California at Berkeley Berkeley, CA, USA
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24
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Gao Y, Min K, Zhang Y, Su J, Greenwood M, Gronert K. Female-Specific Downregulation of Tissue Polymorphonuclear Neutrophils Drives Impaired Regulatory T Cell and Amplified Effector T Cell Responses in Autoimmune Dry Eye Disease. J Immunol 2015; 195:3086-99. [PMID: 26324767 DOI: 10.4049/jimmunol.1500610] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Accepted: 07/27/2015] [Indexed: 12/19/2022]
Abstract
Immune-driven dry eye disease primarily affects women; the cause for this sex-specific prevalence is unknown. Polymorphonuclear neutrophils (PMN) have distinct phenotypes that drive inflammation but also regulate lymphocytes and are the rate-limiting cell for generating anti-inflammatory lipoxin A4 (LXA4). Estrogen regulates the LXA4 circuit to induce delayed female-specific wound healing in the cornea. However, the role of PMNs in dry eye disease remains unexplored. We discovered an LXA4-producing tissue PMN population in the corneal limbus, lacrimal glands, and cervical lymph nodes of healthy male and female mice. These tissue PMNs, unlike inflammatory PMNs, expressed a highly amplified LXA4 circuit and were sex-specifically regulated during immune-driven dry eye disease. Desiccating stress in females, unlike in males, triggered a remarkable decrease in lymph node PMN and LXA4 formation that remained depressed during dry eye disease. Depressed lymph node PMN and LXA4 in females correlated with an increase in effector T cells (Th1 and Th17), a decrease in regulatory T cells (Treg), and increased dry eye pathogenesis. Ab depletion of tissue PMN abrogated LXA4 formation in lymph nodes, as well as caused a marked increase in Th1 and Th17 cells and a decrease in Tregs. To establish an immune-regulatory role for PMN-derived LXA4 in dry eye, females were treated with LXA4. LXA4 treatment markedly inhibited Th1 and Th17 and amplified Treg in draining lymph nodes, while reducing dry eye pathogenesis. These results identify female-specific regulation of LXA4-producing tissue PMN as a potential key factor in aberrant effector T cell activation and initiation of immune-driven dry eye disease.
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Affiliation(s)
- Yuan Gao
- Vision Science Program, School of Optometry, University of California Berkeley, Berkeley, CA 94598
| | - Kyungji Min
- Vision Science Program, School of Optometry, University of California Berkeley, Berkeley, CA 94598
| | - Yibing Zhang
- Vision Science Program, School of Optometry, University of California Berkeley, Berkeley, CA 94598
| | - John Su
- Vision Science Program, School of Optometry, University of California Berkeley, Berkeley, CA 94598
| | - Matthew Greenwood
- Vision Science Program, School of Optometry, University of California Berkeley, Berkeley, CA 94598
| | - Karsten Gronert
- Vision Science Program, School of Optometry, University of California Berkeley, Berkeley, CA 94598
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25
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Pazos MA, Pirzai W, Yonker LM, Morisseau C, Gronert K, Hurley BP. Distinct cellular sources of hepoxilin A3 and leukotriene B4 are used to coordinate bacterial-induced neutrophil transepithelial migration. J Immunol 2014; 194:1304-15. [PMID: 25548217 DOI: 10.4049/jimmunol.1402489] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Neutrophilic infiltration is a leading contributor to pathology in a number of pulmonary disease states, including cystic fibrosis. Hepoxilin A3 (HXA3) is a chemotactic eicosanoid shown to mediate the transepithelial passage of neutrophils in response to infection in several model systems and at multiple mucosal surfaces. Another well-known eicosanoid mediating general neutrophil chemotaxis is leukotriene B4 (LTB4). We sought to distinguish the roles of each eicosanoid in the context of infection of lung epithelial monolayers by Pseudomonas aeruginosa. Using human and mouse in vitro transwell model systems, we used a combination of biosynthetic inhibitors, receptor antagonists, as well as mutant sources of neutrophils to assess the contribution of each chemoattractant in driving neutrophil transepithelial migration. We found that following chemotaxis to epithelial-derived HXA3 signals, neutrophil-derived LTB4 is required to amplify the magnitude of neutrophil migration. LTB4 signaling is not required for migration to HXA3 signals, but LTB4 generation by migrated neutrophils plays a significant role in augmenting the initial HXA3-mediated migration. We conclude that HXA3 and LTB4 serve independent roles to collectively coordinate an effective neutrophilic transepithelial migratory response.
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Affiliation(s)
- Michael A Pazos
- Mucosal Immunology and Biology Research Center, Massachusetts General Hospital for Children, Charlestown, MA 02129; Department of Pediatrics, Harvard Medical School, Boston, MA 02115
| | - Waheed Pirzai
- Mucosal Immunology and Biology Research Center, Massachusetts General Hospital for Children, Charlestown, MA 02129; Department of Pediatrics, Harvard Medical School, Boston, MA 02115
| | - Lael M Yonker
- Mucosal Immunology and Biology Research Center, Massachusetts General Hospital for Children, Charlestown, MA 02129; Department of Pediatrics, Harvard Medical School, Boston, MA 02115
| | - Christophe Morisseau
- Department of Entomology and University of California Davis Comprehensive Cancer Center, University of California, Davis, CA 95616; and
| | - Karsten Gronert
- Vision Science Program, School of Optometry, University of California at Berkeley, Berkeley, CA 94720
| | - Bryan P Hurley
- Mucosal Immunology and Biology Research Center, Massachusetts General Hospital for Children, Charlestown, MA 02129; Department of Pediatrics, Harvard Medical School, Boston, MA 02115;
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26
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27
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Kalish BT, Le HD, Fitzgerald JM, Wang S, Seamon K, Gura KM, Gronert K, Puder M. Intravenous fish oil lipid emulsion promotes a shift toward anti-inflammatory proresolving lipid mediators. Am J Physiol Gastrointest Liver Physiol 2013; 305:G818-28. [PMID: 24091595 PMCID: PMC3882434 DOI: 10.1152/ajpgi.00106.2013] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Parenteral nutrition (PN)-associated liver disease (PNALD) is a life-threatening complication of the administration of PN. The development of PNALD may be partly due to the composition of the lipid emulsion administered with PN: soybean oil-based lipid emulsions (SOLE) are associated with liver disease, while fish oil-based lipid emulsions (FOLE) are associated with prevention and improvement of liver disease. The objective of this study was to determine how the choice of lipid emulsion modified the production of bioactive lipid mediators (LMs). We utilized a mouse model of steatosis to study the differential effect of FOLE and SOLE. We subsequently validated these results in serum samples from a small cohort of human infants transitioning from SOLE to FOLE. In mice, FOLE was associated with production of anti-inflammatory, proresolving LMs; SOLE was associated with increased production of inflammatory LMs. In human infants, the transition from SOLE to FOLE was associated with a shift toward a proresolving lipidome. Together, these results demonstrate that the composition of the lipid emulsion directly modifies inflammatory homeostasis.
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Affiliation(s)
- Brian T. Kalish
- 1Department of Surgery and The Vascular Biology Program, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts;
| | - Hau D. Le
- 1Department of Surgery and The Vascular Biology Program, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts; ,2Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts;
| | - Jonathan M. Fitzgerald
- 3Center for Experimental Therapeutics and Reperfusion Injury, Department of Anesthesiology, Perioperative, and Pain Medicine, Brigham and Women's Hospital, Harvard Medical School, Harvard Institutes of Medicine, Boston, Massachusetts;
| | - Samantha Wang
- 4Vision Science Program, School of Optometry, University of California, Berkeley, Berkeley, California; and
| | - Kyle Seamon
- 4Vision Science Program, School of Optometry, University of California, Berkeley, Berkeley, California; and
| | - Kathleen M. Gura
- 5Department of Pharmacy, Boston Children's Hospital, Boston, Massachusetts
| | - Karsten Gronert
- 4Vision Science Program, School of Optometry, University of California, Berkeley, Berkeley, California; and
| | - Mark Puder
- 1Department of Surgery and The Vascular Biology Program, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts;
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28
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Bhowmick R, Maung N, Hurley BP, Ghanem EB, Gronert K, McCormick BA, Leong JM. Systemic disease during Streptococcus pneumoniae acute lung infection requires 12-lipoxygenase-dependent inflammation. J Immunol 2013; 191:5115-23. [PMID: 24089193 DOI: 10.4049/jimmunol.1300522] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Acute pulmonary infection by Streptococcus pneumoniae is characterized by high bacterial numbers in the lung, a robust alveolar influx of polymorphonuclear cells (PMNs), and a risk of systemic spread of the bacterium. We investigated host mediators of S. pneumoniae-induced PMN migration and the role of inflammation in septicemia following pneumococcal lung infection. Hepoxilin A3 (HXA3) is a PMN chemoattractant and a metabolite of the 12-lipoxygenase (12-LOX) pathway. We observed that S. pneumoniae infection induced the production of 12-LOX in cultured pulmonary epithelium and in the lungs of infected mice. Inhibition of the 12-LOX pathway prevented pathogen-induced PMN transepithelial migration in vitro and dramatically reduced lung inflammation upon high-dose pulmonary challenge with S. pneumoniae in vivo, thus implicating HXA3 in pneumococcus-induced pulmonary inflammation. PMN basolateral-to-apical transmigration in vitro significantly increased apical-to-basolateral transepithelial migration of bacteria. Mice suppressed in the expression of 12-LOX exhibited little or no bacteremia and survived an otherwise lethal pulmonary challenge. Our data suggest that pneumococcal pulmonary inflammation is required for high-level bacteremia and systemic infection, partly by disrupting lung epithelium through 12-LOX-dependent HXA3 production and subsequent PMN transepithelial migration.
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Affiliation(s)
- Rudra Bhowmick
- Department of Molecular Biology and Microbiology, Tufts University, Boston, MA 02111, USA
| | - Nang Maung
- Immune Disease Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Bryan P Hurley
- Mucosal Immunology Laboratory, Massachusetts General Hospital/Harvard Medical School, Charlestown, MA 02129, USA
| | - Elsa Bou Ghanem
- Department of Molecular Biology and Microbiology, Tufts University, Boston, MA 02111, USA
| | - Karsten Gronert
- Vision Science Program, School of Optometry, University of California, Berkeley, CA 94720, USA
| | - Beth A McCormick
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - John M Leong
- Department of Molecular Biology and Microbiology, Tufts University, Boston, MA 02111, USA
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Prüss H, Rosche B, Sullivan AB, Brommer B, Wengert O, Gronert K, Schwab JM. Proresolution lipid mediators in multiple sclerosis - differential, disease severity-dependent synthesis - a clinical pilot trial. PLoS One 2013; 8:e55859. [PMID: 23409068 PMCID: PMC3568070 DOI: 10.1371/journal.pone.0055859] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2012] [Accepted: 01/03/2013] [Indexed: 01/17/2023] Open
Abstract
BACKGROUND The severity and longevity of inflammation is controlled by endogenous counter-regulatory signals. Among them are long-chain polyunsaturated fatty acid (PUFA)-derived lipid mediators, which promote the resolution of inflammation, an active process for returning to tissue homeostasis. OBJECTIVE To determine whether endogenous production of lipid-derived resolution agonists is regulated differentially in patients with highly active and less active multiple sclerosis (MS). DESIGN Matched-pairs study in University hospital Neurology department. PATIENTS Based on clinical (relapse frequency) and paraclinical (MRI lesions, contrast enhancement) criteria, 10 pairs of age- and sex-matched patients with relapsing-remitting MS were assigned either to a group with highly active or less active MS. Lipid mediators were quantified in serum and cerebrospinal fluid using LC-MS/MS-based lipidomics. RESULTS Levels of the key arachidonic (ω-6) and docosahexaenoic acid (ω-6)-derived mediators prostaglandins (PG), leukotrienes, hydroxyeicosatetraenoic acids (HETE) and resolution agonists lipoxin A(4) (LXA(4)), resolvin D1 (RvD1) and neuroprotectin D1 (NPD1) were quantified. In the patient group with highly active MS, 15-HETE and PGE(2) were increased, which are products of the 15-lipoxygenase and cyclooxygenase pathways. The proresolution mediator RvD1 was significantly upregulated and NPD1 was detected in the highly active group only. LXA(4) levels were not increased in patients with highly active MS. CONCLUSIONS Lipid mediator pathways are regulated differentially in the cerebrospinal fluid of MS patients, depending on disease severity. Non-exhaustive or possibly 'delayed' resolution pathways may suggest a defective resolution program in patients with highly active MS. Longitudinal analyses are required to hetero-typify this differential resolution capacity, which may be associated with disease progression, longevity and eventual termination.
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Affiliation(s)
- Harald Prüss
- Department of Neurology & Experimental Neurology, Charité University Medicine Berlin, Berlin, Germany
- * E-mail: (JMS); (HP)
| | - Berit Rosche
- Department of Neurology & Experimental Neurology, Charité University Medicine Berlin, Berlin, Germany
| | - Aaron B. Sullivan
- Vision Science Program, School of Optometry, University of California, Berkeley, California, United States of America
| | - Benedikt Brommer
- Department of Neurology & Experimental Neurology, Charité University Medicine Berlin, Berlin, Germany
| | - Oliver Wengert
- Department of Neurology & Experimental Neurology, Charité University Medicine Berlin, Berlin, Germany
| | - Karsten Gronert
- Vision Science Program, School of Optometry, University of California, Berkeley, California, United States of America
| | - Jan M. Schwab
- Department of Neurology & Experimental Neurology, Charité University Medicine Berlin, Berlin, Germany
- * E-mail: (JMS); (HP)
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30
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Tamang DL, Pirzai W, Priebe GP, Traficante DC, Pier GB, Falck JR, Morisseau C, Hammock BD, McCormick BA, Gronert K, Hurley BP. Hepoxilin A(3) facilitates neutrophilic breach of lipoxygenase-expressing airway epithelial barriers. J Immunol 2012; 189:4960-9. [PMID: 23045615 DOI: 10.4049/jimmunol.1201922] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A feature shared by many inflammatory lung diseases is excessive neutrophilic infiltration. Neutrophil homing to airspaces involve multiple factors produced by several distinct cell types. Hepoxilin A(3) is a neutrophil chemoattractant produced by pathogen-infected epithelial cells that is hypothesized to facilitate neutrophil breach of mucosal barriers. Using a Transwell model of lung epithelial barriers infected with Pseudomonas aeruginosa, we explored the role of hepoxilin A(3) in neutrophil transepithelial migration. Pharmacological inhibitors of the enzymatic pathways necessary to generate hepoxilin A(3), including phospholipase A(2) and 12-lipoxygenase, potently interfere with P. aeruginosa-induced neutrophil transepithelial migration. Both transformed and primary human lung epithelial cells infected with P. aeruginosa generate hepoxilin A(3) precursor arachidonic acid. All four known lipoxygenase enzymes capable of synthesizing hepoxilin A(3) are expressed in lung epithelial cell lines, primary small airway epithelial cells, and human bronchial epithelial cells. Lung epithelial cells produce increased hepoxilin A(3) and lipid-derived neutrophil chemotactic activity in response to P. aeruginosa infection. Lipid-derived chemotactic activity is soluble epoxide hydrolase sensitive, consistent with hepoxilin A(3) serving a chemotactic role. Stable inhibitory structural analogs of hepoxilin A(3) are capable of impeding P. aeruginosa-induced neutrophil transepithelial migration. Finally, intranasal infection of mice with P. aeruginosa promotes enhanced cellular infiltrate into the airspace, as well as increased concentration of the 12-lipoxygenase metabolites hepoxilin A(3) and 12-hydroxyeicosa-5Z,8Z,10E,14Z-tetraenoic acid. Data generated from multiple models in this study provide further evidence that hepoxilin A(3) is produced in response to lung pathogenic bacteria and functions to drive neutrophils across epithelial barriers.
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Affiliation(s)
- David L Tamang
- Mucosal Immunology Laboratory, Massachusetts General Hospital, Charlestown, MA 02129, USA
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31
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von Moltke J, Trinidad NJ, Moayeri M, Kintzer AF, Wang SB, van Rooijen N, Brown CR, Krantz BA, Leppla SH, Gronert K, Vance RE. Rapid induction of inflammatory lipid mediators by the inflammasome in vivo. Nature 2012; 490:107-11. [PMID: 22902502 PMCID: PMC3465483 DOI: 10.1038/nature11351] [Citation(s) in RCA: 343] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Accepted: 06/26/2012] [Indexed: 01/21/2023]
Abstract
Detection of microbial products by host inflammasomes is critical for innate immune surveillance. Inflammasomes activate the CASPASE-1 (CASP1) protease, which processes the cytokines interleukin(IL)-1β and -18, and initiates a lytic host cell death called pyroptosis1. To identify novel CASP1 functions in vivo, we devised a strategy for cytosolic delivery of bacterial flagellin, a specific ligand for the NAIP5 (NLR family, apoptosis inhibitory protein 5)/NLRC4 (NLR family, CARD domain containing 4) inflammasome2–4. Here we show that systemic inflammasome activation by flagellin leads to loss of vascular fluid into the intestine and peritoneal cavity, resulting in rapid (< 30 minutes) death in mice. This unexpected response depends on the inflammasome components NAIP5, NLRC4, and CASP1, but is independent of IL-1β/-18 production. Instead, inflammasome activation results, within minutes, in an ‘eicosanoid storm’ – a pathological release of signaling lipids that rapidly initiate inflammation and vascular fluid loss. Mice deficient in cyclooxygenase-1 (COX-1), a critical enzyme in prostaglandin biosynthesis, are resistant to these rapid pathological effects of systemic inflammasome activation by either flagellin or anthrax lethal toxin. Inflammasome-dependent biosynthesis of eicosanoids is mediated by activation of cPLA2 (cytosolic phospholipase A2) in resident peritoneal macrophages, which are specifically primed for production of eicosanoids by high expression of eicosanoid biosynthetic enzymes. Thus, our results identify eicosanoids as a novel cell type-specific signaling output of the inflammasome with dramatic physiological consequences in vivo.
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Affiliation(s)
- Jakob von Moltke
- Department of Molecular and Cell Biology, Division of Immunology and Pathogenesis, University of California at Berkeley, Berkeley, California 94720, USA
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32
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von Moltke J, Moayeri M, Trinidad N, Kintzer A, Wang S, van Rooijen N, Krantz B, Leppla S, Gronert K, Vance R. Rapid induction of lipid mediators is a novel effector function of the inflammasome in vivo (117.24). The Journal of Immunology 2012. [DOI: 10.4049/jimmunol.188.supp.117.24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
Detection of microbial products by host inflammasomes is critical for innate immune surveillance, while eicosanoids, signaling lipids that include the prostaglandins and leukotrienes, are rapid triggers of inflammation. Here we report for the first time a link between inflammasome activation and eicosanoid synthesis. Using a novel protein toxin, we show that systemic cytosolic delivery of bacterial flagellin in vivo leads to loss of vascular fluid into the intestine and peritoneal cavity, resulting in rapid (<30 min) death in mice. This unexpected response is dependent on the inflammasome components NAIP5, NLRC4, and CASP1, but interestingly, is independent of the known inflammasome effector functions, namely IL-1β/-18 production and pyroptotic cell death. Instead, inflammasome activation in resident peritoneal macrophages results, within minutes, in the release of prostaglandins and other eicosanoids that induce vascular fluid loss. Mice deficient in cyclooxygenase-1, a critical enzyme in prostaglandin biosynthesis, are resistant to the pathological effects of systemic inflammasome activation. Compared to other macrophage populations, resident peritoneal macrophages are specifically primed for inflammasome-dependent production of eicosanoids by high expression of Cox1 and other eicosanoid biosynthetic enzymes. Thus, our results identify eicosanoid production as a novel cell type-specific effector function of the inflammasome with dramatic physiological consequences in vivo.
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Affiliation(s)
- Jakob von Moltke
- 1Molecular & Cell Biology, Division of Immunology & Pathogenesis, UC Berkeley, Berkeley, CA
| | - Mahtab Moayeri
- 4Laboratory of Parasitic Diseases, Microbial Pathogenesis Section, NIAID, NIH, Bethesda, MD
| | - Norver Trinidad
- 1Molecular & Cell Biology, Division of Immunology & Pathogenesis, UC Berkeley, Berkeley, CA
| | | | - Samantha Wang
- 3Vision Science Program, School of Optometry, UC Berkeley, Berkeley, CA
| | - Nico van Rooijen
- 5Molecular & Cell Biology, Vrije Universiteit Medisch Centrum, Amsterdam, Netherlands
| | - Bryan Krantz
- 2Department of Chemistry, UC Berkeley, Berkeley, CA
| | - Stephen Leppla
- 4Laboratory of Parasitic Diseases, Microbial Pathogenesis Section, NIAID, NIH, Bethesda, MD
| | - Karsten Gronert
- 3Vision Science Program, School of Optometry, UC Berkeley, Berkeley, CA
| | - Russell Vance
- 1Molecular & Cell Biology, Division of Immunology & Pathogenesis, UC Berkeley, Berkeley, CA
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Wang SB, Hu KM, Seamon KJ, Mani V, Chen Y, Gronert K. Estrogen negatively regulates epithelial wound healing and protective lipid mediator circuits in the cornea. FASEB J 2011; 26:1506-16. [PMID: 22186873 DOI: 10.1096/fj.11-198036] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Estrogen receptors (ERs) are expressed in leukocytes and in every ocular tissue. However, sex-specific differences and the role of estradiol in ocular inflammatory-reparative responses are not well understood. We found that female mice exhibited delayed corneal epithelial wound closure and attenuated polymorphonuclear (PMN) leukocyte responses, a phenotype recapitulated by estradiol treatment both in vivo (topically in male mice) and in vitro (corneal epithelial cell wound healing). The cornea expresses 15-lipoxygenase (15-LOX) and receptors for lipoxin A(4) (LXA(4)), which have been implicated in an intrinsic lipid circuit that regulates corneal inflammation and wound healing. Delayed epithelial wound healing correlated with lower expression of 15-LOX in the regenerated epithelium of female mice. Estradiol in vitro and in vivo down-regulated epithelial 15-LOX expression and LXA(4) formation, while estradiol abrogation of epithelial wound healing was completely reversed by treatment with LXA(4). More important, ERβ and ERα selectively regulated epithelial wound healing, PMN cell recruitment, and activity of the intrinsic 15-LOX/LXA(4) circuit. Our results demonstrate for the first time a sex-specific difference in the corneal reparative response, which is mediated by ERβ and ERα selective regulation of the epithelial and PMN 15-LOX/LXA(4) circuit. These findings may provide novel insights into the etiology of sex-specific ocular inflammatory diseases.
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Affiliation(s)
- Samantha B Wang
- University of California, Berkeley, Vision Science Program, School of Optometry, 594 Minor Hall, MC 2020, Berkeley, CA 94720-2020, USA
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Krishnan T, Prajna NV, Gronert K, Oldenburg CE, Ray KJ, Keenan JD, Lietman TM, Acharya NR. Gender differences in re-epithelialisation time in fungal corneal ulcers. Br J Ophthalmol 2011; 96:137-8. [PMID: 21979901 DOI: 10.1136/bjophthalmol-2011-300441] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Sapieha P, Stahl A, Chen J, Seaward MR, Willett KL, Krah NM, Dennison RJ, Connor KM, Aderman CM, Liclican E, Carughi A, Perelman D, Kanaoka Y, Sangiovanni JP, Gronert K, Smith LEH. 5-Lipoxygenase metabolite 4-HDHA is a mediator of the antiangiogenic effect of ω-3 polyunsaturated fatty acids. Sci Transl Med 2011; 3:69ra12. [PMID: 21307302 DOI: 10.1126/scitranslmed.3001571] [Citation(s) in RCA: 184] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Lipid signaling is dysregulated in many diseases with vascular pathology, including cancer, diabetic retinopathy, retinopathy of prematurity, and age-related macular degeneration. We have previously demonstrated that diets enriched in ω-3 polyunsaturated fatty acids (PUFAs) effectively reduce pathological retinal neovascularization in a mouse model of oxygen-induced retinopathy, in part through metabolic products that suppress microglial-derived tumor necrosis factor-α. To better understand the protective effects of ω-3 PUFAs, we examined the relative importance of major lipid metabolic pathways and their products in contributing to this effect. ω-3 PUFA diets were fed to four lines of mice deficient in each key lipid-processing enzyme (cyclooxygenase 1 or 2, or lipoxygenase 5 or 12/15), retinopathy was induced by oxygen exposure; only loss of 5-lipoxygenase (5-LOX) abrogated the protection against retinopathy of dietary ω-3 PUFAs. This protective effect was due to 5-LOX oxidation of the ω-3 PUFA lipid docosahexaenoic acid to 4-hydroxy-docosahexaenoic acid (4-HDHA). 4-HDHA directly inhibited endothelial cell proliferation and sprouting angiogenesis via peroxisome proliferator-activated receptor γ (PPARγ), independent of 4-HDHA's anti-inflammatory effects. Our study suggests that ω-3 PUFAs may be profitably used as an alternative or supplement to current anti-vascular endothelial growth factor (VEGF) treatment for proliferative retinopathy and points to the therapeutic potential of ω-3 PUFAs and metabolites in other diseases of vasoproliferation. It also suggests that cyclooxygenase inhibitors such as aspirin and ibuprofen (but not lipoxygenase inhibitors such as zileuton) might be used without losing the beneficial effect of dietary ω-3 PUFA.
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Affiliation(s)
- Przemyslaw Sapieha
- Department of Ophthalmology, Harvard Medical School, Children's Hospital Boston, 300 Longwood Avenue, Boston, MA 02115, USA
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Bhowmick R, Gronert K, McCormick B, Leong J. The eicosanoid hepoxilin A3 plays critical role in transmigration of PMNs and concomitant invasion of bacteria in Streptococcus pneumoniae lung infection (56.11). The Journal of Immunology 2011. [DOI: 10.4049/jimmunol.186.supp.56.11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
The hallmark of pneumonia caused by Streptococcus pneumoniae (pneumococcus) is massive recruitment of polymorphonuclear cells (PMNs) from the circulation into lung alveolar spaces, causing considerable tissue damage. Moreover, pneumococcal translocation across lung epithelium into blood can lead to potentially lethal septicemia. The PMN influx caused by the bacterial insult, might lead to the disruption of the barrier function of the respiratory epithelium, thus contributing to the transepithelial migration of S. pneumoniae into the bloodstream. Our results show that S. pneumoniae triggered PMN migration from basolateral to apical side of polarized monolayers of lung epithelial cell line H292, and this PMN migration was associated with elevated levels of bacterial migration in the reverse direction. HPLC/MS studies of infected H292 culture supernatants showed increased levels of hepoxilin A3 (HXA3), a 12-LOX-derived eicosanoid that can act as a PMN chemoattractant. Administration of a 12-LOX inhibitor significantly reduced both pneumococcus-induced PMN migration and translocation of bacteria itself. Interestingly, 12-LOX knockout mice, or wild type mice treated with a 12-LOX inhibitor, showed diminished lung inflammation and bacteremia, and showed 100% survival in an otherwise lethal lung challenge. Our results indicate that during S. pneumoniae lung infection, HXA3 plays important roles in both pulmonary inflammation and bacterial invasion of the bloodstream.
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Affiliation(s)
- Rudra Bhowmick
- 1University of Massachusetts Medical School, Worcester, MA
| | | | - Beth McCormick
- 1University of Massachusetts Medical School, Worcester, MA
| | - John Leong
- 1University of Massachusetts Medical School, Worcester, MA
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Hurley BP, Pirzai W, Mumy KL, Gronert K, McCormick BA. Selective eicosanoid-generating capacity of cytoplasmic phospholipase A2 in Pseudomonas aeruginosa-infected epithelial cells. Am J Physiol Lung Cell Mol Physiol 2010; 300:L286-94. [PMID: 21097525 DOI: 10.1152/ajplung.00147.2010] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Airway neutrophil infiltration is a pathological hallmark observed in multiple lung diseases including pneumonia and cystic fibrosis. Bacterial pathogens such as Pseudomonas aeruginosa instigate neutrophil recruitment to the air space. Excessive accumulation of neutrophils in the lung often contributes to tissue destruction. Previous studies have unveiled hepoxilin A(3) as the key molecular signal driving neutrophils across epithelial barriers. The eicosanoid hepoxilin A(3) is a potent neutrophil chemoattractant produced by epithelial cells in response to infection with P. aeruginosa. The enzyme phospholipase A(2) liberates arachidonic acid from membrane phospholipids, the rate-limiting step in the synthesis of all eicosanoids, including hepoxilin A(3). Once generated, aracidonic acid is acted upon by multiple cyclooxygenases and lipoxygenases producing an array of functionally diverse eicosanoids. Although there are numerous phospholipase A(2) isoforms capable of generating arachidonic acid, the isoform most often associated with eicosanoid generation is cytoplasmic phospholipase A(2)α. In the current study, we observed that the cytoplasmic phospholipase A(2)α isoform is required for mediating P. aeruginosa-induced production of certain eicosanoids such as prostaglandin E(2). However, we found that neutrophil transepithelial migration induced by P. aeruginosa does not require cytoplasmic phospholipase A(2)α. Furthermore, P. aeruginosa-induced hepoxilin A(3) production persists despite cytoplasmic phospholipase A(2)α suppression and generation of the 12-lipoxygenase metabolite 12-HETE is actually enhanced in this context. These results suggest that alterative phospholipase A(2) isoforms are utilized to synthesize 12-lipoxygenase metabolites. The therapeutic implications of these findings are significant when considering anti-inflammatory therapies based on targeting eicosanoid synthesis pathways.
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Affiliation(s)
- Bryan P Hurley
- Mucosal Immunology, Massachusetts General Hospital, Charlestown, 02129, USA.
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Abstract
Acute inflammation is a frequent, essential and beneficial response to maintain normal tissue function. PMN are the primary effector cells of acute inflammatory responses and their timely resolution by macrophages from an injured, stressed or infected tissues are required for the successful execution of this routine tissue response. Dysregulation of this fundamental program is a major factor in the global disease burden and contributes to many ocular diseases. Counter-regulatory signals are critical to the controlled activation of innate and adaptive immune responses in the eye and recent studies have identified two circuits in the cornea, uvea and/or retina, namely 15-lipoxygenase and heme-oxygenase, which control inflammation, promote resolution of PMN and afford neuroprotection. The role of these counter-regulator and pro-resolution circuits may provide insight into ocular inflammatory diseases and opportunities to restore stressed ocular tissue to a pre-inflammatory state, namely homeostasis, rather than limiting therapeutic options to palliative inhibition of pro-inflammatory circuits.
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Affiliation(s)
- Karsten Gronert
- Vision Science Program, School of Optometry, University of California, 594 Minor Hall, MC 2020, Berkeley, CA 94720, USA.
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Liclican EL, Nguyen V, Sullivan AB, Gronert K. Selective activation of the prostaglandin E2 circuit in chronic injury-induced pathologic angiogenesis. Invest Ophthalmol Vis Sci 2010; 51:6311-20. [PMID: 20610836 DOI: 10.1167/iovs.10-5455] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
PURPOSE Cyclooxygenase (COX)-derived prostaglandin E(2) (PGE(2)) is a prevalent and established mediator of inflammation and pain in numerous tissues and diseases. Distribution and expression of the four PGE(2) receptors (EP1-EP4) can dictate whether PGE(2) exerts an anti-inflammatory or a proinflammatory and/or a proangiogenic effect. The role and mechanism of endogenous PGE(2) in the cornea, and the regulation of EP expression during a dynamic and complex inflammatory/reparative response remain to be clearly defined. METHODS Chronic or acute self-resolving inflammation was induced in mice by corneal suture or epithelial abrasion, respectively. Reepithelialization was monitored by fluorescein staining and neovascularization quantified by CD31/PECAM-1 immunofluorescence. PGE(2) formation was analyzed by lipidomics and polymorphonuclear leukocyte (PMN) infiltration quantified by myeloperoxidase activity. Expression of EPs and inflammatory/angiogenic mediators was assessed by real-time PCR and immunohistochemistry. Mice eyes were treated with PGE(2) (100 ng topically, three times a day) for up to 7 days. RESULTS COX-2, EP-2, and EP-4 expression was upregulated with chronic inflammation that correlated with increased corneal PGE(2) formation and marked neovascularization. In contrast, acute abrasion injury did not alter PGE(2) or EP levels. PGE(2) treatment amplified PMN infiltration and the angiogenic response to chronic inflammation but did not affect wound healing or PMN infiltration after epithelial abrasion. Exacerbated inflammatory neovascularization with PGE(2) treatment was independent of the VEGF circuit but was associated with a significant induction of the eotaxin-CCR3 axis. CONCLUSIONS These findings place the corneal PGE(2) circuit as an endogenous mediator of inflammatory neovascularization rather than general inflammation and demonstrate that chronic inflammation selectively regulates this circuit at the level of biosynthetic enzyme and receptor expression.
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Affiliation(s)
- Elvira L Liclican
- Vision Science Program, School of Optometry, University of California at Berkeley, Berkeley, CA 94720-2020, USA
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Abstract
Lipid autacoids have well-established key roles in physiology and pathophysiology. Eicosanoids derived from ω-6 arachidonic acid (AA) have long been recognized for their roles in cardiovascular and renal functions, and vascular tone, as well as regulating inflammatory and immune functions. It is now appreciated that AA is a substrate for generating lipid mediators with anti-inflammatory and proresolving properties, namely lipoxins (i.e., LXA4), which are an integral component for the successful execution of beneficial and essential acute inflammatory responses. In addition to AA, the ω-3 polyunsaturated fatty acids (PUFAs) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) also serve as substrates to generate potent and protective autacoids, such as resolvins and neuroprotectin (i.e., NPD1), respectively. These ω-3–derived signals may mediate the remarkable protective action of essential dietary ω-3 PUFAs. Formation and bioactivity of lipid mediators in the eye are relatively unexplored and of considerable interest, as the eye contains highly specialized tissues, including the transparent avascular and immune-privileged cornea, and the neuro-retina. A rapidly emerging field has identified key biosynthetic enzymes, receptors, and temporally defined endogenous formation of ω-3– and ω-6–derived protective lipid circuits in the eye. Protective endogenous roles of LXA4 and NPD1 have been established utilizing lipidomic analysis, knockout mice, and pharmacological, genetic, and dietary manipulation, providing compelling evidence that these intrinsic lipid autacoid circuits play essential roles in restraining inflammation, promoting wound healing, inhibiting pathological angiogenesis, and providing neuroprotection in the delicate visual axis.
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Affiliation(s)
- Elvira L Liclican
- Vision Science Program, School of Optometry, University of California, Berkeley, CA, USA
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Leedom AJ, Sullivan AB, Dong B, Lau D, Gronert K. Endogenous LXA4 circuits are determinants of pathological angiogenesis in response to chronic injury. Am J Pathol 2009; 176:74-84. [PMID: 20008149 DOI: 10.2353/ajpath.2010.090678] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Inflammation and angiogenesis are intimately linked, and their dysregulation leads to pathological angiogenesis in human diseases. 15-lipoxygenase (15-LOX) and lipoxin A(4) receptors (ALX) constitute a LXA(4) circuit that is a key feature of inflammatory resolution. LXA(4) analogs have been shown to regulate vascular endothelial growth factor (VEGF)-A-induced angiogenic response in vitro. 15-LOX and ALX are highly expressed in the avascular and immune-privileged cornea. However, the role of this endogenous LXA(4) circuit in pathological neovascularization has not been determined. We report that suture-induced chronic injury in the cornea triggered polymorphonuclear leukocytes (PMN) infiltration, pathological neovascularization, and up-regulation of mediators of inflammatory angiogenesis, namely VEGF-A and the VEGF-3 receptor (FLT4). Up-regulation of the VEGF circuit and neovascularization correlated with selective changes in both 15-LOX (Alox15) and ALX (Fpr-rs2) expression and a temporally defined increase in basal 15-LOX activity. More importantly, genetic deletion of 15-LOX or 5-LOX, key and obligatory enzymes in the formation of LXA(4), respectively, led to exacerbated inflammatory neovascularization coincident with increased VEGF-A and FLT4 expression. Direct topical treatment with LXA(4), but not its metabolic precursor 15-hydroxyeicosatetraenoic acid, reduced expression of VEGF-A and FLT4 and inflammatory angiogenesis and rescued 15-LOX knockout mice from exacerbated angiogenesis. In summary, our findings and the prominent expression of 15-LOX and ALX in epithelial cells and macrophages place the LXA(4) circuit as an endogenous regulator of pathological angiogenesis.
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Affiliation(s)
- Alexander J Leedom
- Vision Science Program, School of Optometry, University of California, Berkeley, CA 94720-2020, USA
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Hassan IR, Gronert K. Acute changes in dietary omega-3 and omega-6 polyunsaturated fatty acids have a pronounced impact on survival following ischemic renal injury and formation of renoprotective docosahexaenoic acid-derived protectin D1. J Immunol 2009; 182:3223-32. [PMID: 19234220 DOI: 10.4049/jimmunol.0802064] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Exacerbated inflammation plays an important role in the pathogenesis of ischemic renal injury (IRI), which is the major cause of intrinsic acute renal failure. Clinical studies suggest that long-term treatment with omega-3 polyunsaturated fatty acids (PUFA) improves renal function and lowers the risk of death or end-stage renal disease. Docosahexaenoic acid, a principle omega-3 PUFA of fish oils, is of particular interest as it is found in most human tissues and is converted to protectin D1 (PD1), which exhibits antiinflammatory and proresolving bioactions. We set out to investigate the impact of acute dietary modulation of omega-3 or omega-6 PUFA on IRI and renal lipid autacoid circuits, using an established mouse model and liquid chromatography-mass spectroscopy/mass spectroscopy-based lipidomics. Thirty minutes of renal ischemia significantly elevated serum creatinine in the omega-6 diet group while renal function remained normal in the matched omega-3 diet group. Notably, extending ischemia to 45 min caused 100% mortality in the omega-6 group, in sharp contrast to 0% mortality in the omega-3 group. Protection against IRI in the omega-3 group correlated with decreased polymorphonuclear leukocyte recruitment, chemokine and cytokine levels, abrogated formation of lipoxygenase- and cyclooxygenase-derived eicosanoids, and increased renal levels of PD1. Systemic treatment with PD1 reduced kidney polymorphonuclear leukocyte influx and, more importantly, amplified renoprotective heme-oxygenase-1 protein and mRNA expression in injured and uninjured kidneys. These findings suggest therapeutic or dietary amplification of PD1 circuits restrains acute renal injury and that short-term changes in dietary omega-3 and omega-6 PUFA dramatically impacts renal lipid autacoid formation and outcome of IRI.
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Affiliation(s)
- Iram R Hassan
- New York Medical College, Department of Pharmacology, Valhalla, NY 10595, USA
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González-Périz A, Horrillo R, Ferré N, Gronert K, Dong B, Morán-Salvador E, Titos E, Martínez-Clemente M, López-Parra M, Arroyo V, Clària J. Obesity-induced insulin resistance and hepatic steatosis are alleviated by omega-3 fatty acids: a role for resolvins and protectins. FASEB J 2009; 23:1946-57. [PMID: 19211925 DOI: 10.1096/fj.08-125674] [Citation(s) in RCA: 429] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Omega-3-polyunsaturated fatty acids (omega-3-PUFAs) have well-documented protective effects that are attributed not only to eicosanoid inhibition but also to the formation of novel biologically active lipid mediators (i.e., resolvins and protectins). In this study, we examined their effects on ob/ob mice, an obesity model of insulin resistance and fatty liver disease. Dietary intake of omega-3-PUFAs had insulin-sensitizing actions in adipose tissue and liver and improved insulin tolerance in obese mice. Genes involved in insulin sensitivity (PPARgamma), glucose transport (GLUT-2/GLUT-4), and insulin receptor signaling (IRS-1/IRS-2) were up-regulated by omega-3-PUFAs. Moreover, omega-3-PUFAs increased adiponectin, an anti-inflammatory and insulin-sensitizing adipokine, and induced AMPK phosphorylation, a fuel-sensing enzyme and a gatekeeper of the energy balance. Concomitantly, hepatic steatosis was alleviated by omega-3-PUFAs. A lipidomic analysis with liquid chromatography/mass spectrometry/mass spectrometry revealed that omega-3-PUFAs inhibited the formation of omega-6-PUFA-derived eicosanoids, while triggering the formation of omega-3-PUFA-derived resolvins and protectins. Moreover, representative members of these lipid mediators, namely resolvin E1 and protectin D1, mimicked the insulin-sensitizing and antisteatotic effects of omega-3-PUFAs and induced adiponectin expression to a similar extent that of rosiglitazone, a member of the thiazolidinedione family of antidiabetic drugs. Taken together, these findings uncover beneficial actions of omega-3-PUFAs and their bioactive lipid autacoids in preventing obesity-induced insulin resistance and hepatic steatosis.
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Affiliation(s)
- Ana González-Périz
- Department of Biochemistry and Molecular Genetics, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi I Sunyer, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas, University of Barcelona, Barcelona, Spain
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Pazos M, Siccardi D, Mumy KL, Bien JD, Louie S, Shi HN, Gronert K, Mrsny RJ, McCormick BA. Multidrug resistance-associated transporter 2 regulates mucosal inflammation by facilitating the synthesis of hepoxilin A3. J Immunol 2008; 181:8044-52. [PMID: 19017997 DOI: 10.4049/jimmunol.181.11.8044] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Neutrophil transmigration across mucosal surfaces contributes to dysfunction of epithelial barrier properties, a characteristic underlying many mucosal inflammatory diseases. Thus, insight into the directional movement of neutrophils across epithelial barriers will provide important information relating to the mechanisms of such inflammatory disorders. The eicosanoid hepoxilin A(3), an endogenous product of 12-lipoxygenase activity, is secreted from the apical surface of the epithelial barrier and establishes a chemotactic gradient to guide neutrophils from the submucosa across epithelia to the luminal site of an inflammatory stimulus, the final step in neutrophil recruitment. Currently, little is known regarding how hepoxilin A(3) is secreted from the intestinal epithelium during an inflammatory insult. In this study, we reveal that hepoxilin A(3) is a substrate for the apical efflux ATP-binding protein transporter multidrug resistance-associated protein 2 (MRP2). Moreover, using multiple in vitro and in vivo models, we show that induction of intestinal inflammation profoundly up-regulates apical expression of MRP2, and that interfering with hepoxilin A(3) synthesis and/or inhibition of MRP2 function results in a marked reduction in inflammation and severity of disease. Lastly, examination of inflamed intestinal epithelia in human biopsies revealed up-regulation of MRP2. Thus, blocking hepoxilin A(3) synthesis and/or inhibiting MRP2 may lead to the development of new therapeutic strategies for the treatment of epithelial-associated inflammatory conditions.
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Affiliation(s)
- Michael Pazos
- Department of Pediatric Gastroenterology and Nutrition, Massachusetts General Hospital, Boston, MA 02129, USA
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Qin Q, Patil KA, Gronert K, Sharma SC. Neuroprotectin D1 inhibits retinal ganglion cell death following axotomy. Prostaglandins Leukot Essent Fatty Acids 2008; 79:201-7. [PMID: 19019647 DOI: 10.1016/j.plefa.2008.09.022] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2008] [Accepted: 09/09/2008] [Indexed: 02/05/2023]
Abstract
Neuroprotectin D1 (NPD1), a docosahexaenoic acid-derived autacoid, is an endogenous neuroprotective and anti-inflammatory mediator that is generated in the retina and brain. The effects of exogenous NPD1 on retinal ganglion cell (RGC) apoptosis and the role of 12/15-lipoxygenase (Alox15) in retina were evaluated after optic nerve transection (ONT). Treatment with NPD1 was associated with significant protection against RGC death. The percentage of RGC survival in NPD1-treated group was 30% at 2 weeks after ONT as compared with 12% of RGC survival in the ONT group without treatment. Endogenous NPD1 was a predominant lipid autocoid in uninjured and axotomized retinas. Alox15 mRNA expression was upregulated in retinas following ONT suggesting that amplification of 12/15-lipoxygenase (12/15-LOX) may represent a neuroprotective response in the rat retina. The density of RGCs was higher in the normal retina of 12/15-LOX-deficient mice as compared with congenic controls. Hence, the resident NPD1 has a potential role in the physiological and pathophysiological responses of the retina.
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Affiliation(s)
- Qiong Qin
- Department of Cell Biology and Anatomy and Ophthalmology, New York Medical College, Valhalla, NY 10595, USA
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Abstract
Host defense is essential to all vertebrates, and programs of inflammation and wound healing must be highly integrated in tissue and organ structures, such as the skin, cornea, and mucosa, that provide crucial barriers and interfaces with the external environment. Certain aspects of inflammation and wound healing have posed a conundrum for biologists, especially to the extent that the two programs may appear to operate in opposition to each other. The recruitment of neutrophils to injured tissue, for example, is essential to inflammation and defense against infection, but can at the same time impair wound healing. One mechanism for regulating this duality is provided by lipid autacoids, which act to restrain leukocyte activation and to promote the resolution of inflammation. Emerging evidence indicates that lipid autacoids also have a central role in wound healing and in fact mediate a privileged injury response, as is observed in the cornea, characterized by rapid healing as well as effective host defense.
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Affiliation(s)
- Karsten Gronert
- University of California, Berkeley, School of Optometry, Minor Hall 594 Berkeley, CA 94720, USA.
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Biteman B, Hassan IR, Walker E, Leedom AJ, Dunn M, Seta F, Laniado-Schwartzman M, Gronert K. Interdependence of lipoxin A4 and heme-oxygenase in counter-regulating inflammation during corneal wound healing. FASEB J 2007; 21:2257-66. [PMID: 17384141 DOI: 10.1096/fj.06-7918com] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In the immune-privileged cornea, epithelial wounds heal rapidly with almost no scarring and, unlike in most other tissues, acute inflammation in the absence of infection is beneficial to healing. Molecular mechanisms, which account for this striking property, remain to be clearly defined, but they likely include autacoids that control leukocyte activation. Two prominent enzymes, 12/15-lipoxygenase (LOX), which generates antiinflammatory lipid autacoids, and heme-oxygenase (HO), which generates antioxidants and carbon monoxide, are highly expressed in human and mouse corneas. LXA4, an endogenous 12/15-LOX product, proved to be a potent inhibitor of exacerbated inflammation and significantly increased re-epithelialization in corneal wounds. In vivo deletion of 12/15-LOX correlated with exacerbated inflammation and impaired wound healing in 12/15-LOX(-/-) mice, a phenotype that was rescued by treatment with LXA4. More importantly, 12/15-LOX(-/-) mice demonstrated impaired induction of HO-1 in both acute and exacerbated inflammation. Topical LXA4 restored HO-1 expression in 12/15-LOX(-/-) mice and amplified HO-1 gene expression in human corneal epithelial cells. HO-2(-/-) mice, which fail to induce HO-1, also demonstrated exacerbated inflammation in response to injury, a phenotype that, notably, correlated with a 50% reduction in endogenous LXA4 formation. Collectively, results demonstrate a critical role for LXA4 in inflammatory/reparative responses and provide the first evidence that 12/15-LOX and HO systems function in concert to control inflammation.
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Affiliation(s)
- Benjamin Biteman
- Department of Pharmacology, New York Medical College, Basic Science Bldg., Valhalla, NY 10595, USA
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Hassan IR, Gronert K. Dietary ω‐3 PUFA‐derived NPD1 is renoprotective and augments cytoprotective heme oxygenase‐1 expression in ischemic renal injury. FASEB J 2007. [DOI: 10.1096/fasebj.21.6.lb85-a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Iram Rehnuma Hassan
- PharmacologyNew York Medical CollegeBasic Sciences Building, Room 546AValhallaNY10595
| | - Karsten Gronert
- PharmacologyNew York Medical CollegeBasic Sciences Building, Room 546AValhallaNY10595
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Seta F, Bellner L, Rezzani R, Regan RF, Dunn MW, Abraham NG, Gronert K, Laniado-Schwartzman M. Heme oxygenase-2 is a critical determinant for execution of an acute inflammatory and reparative response. Am J Pathol 2006; 169:1612-23. [PMID: 17071585 PMCID: PMC1780218 DOI: 10.2353/ajpath.2006.060555] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 07/20/2006] [Indexed: 01/09/2023]
Abstract
Heme oxygenase (HO) represents an intrinsic anti-inflammatory system based on its ability to regulate leukocyte function and inhibit expression of proinflammatory cytokines. This anti-inflammatory function is linked to the inducible isoform HO-1; the role of the constitutive isoform HO-2 is unknown. The current study was undertaken to investigate the role of HO-2 in the regulation of the acute inflammatory and reparative response by using HO-2-null mice and well-established animal models of epithelial injury and antigen-induced peritonitis. Here we show that in vivo deletion of HO-2 disables execution of the acute inflammatory and reparative response after epithelial injury and leads to an exaggerated inflammatory response in antigen-induced peritonitis. HO-2 deletion was associated with impaired HO-1 induction, indicating that HO-2 is critical for HO-1 expression and that the subsequent failure to up-regulate the HO system may contribute to unresolved inflammation and the development of chronic inflammatory conditions. Indeed, supplementation with the HO bioactive product, biliverdin, rescued the acute inflammatory and reparative response in HO-2-null mice. Thus, HO-2 sets in place a basal tone of anti-inflammatory signals that may be a prerequisite for the ordered execution of an inflammatory and reparative response.
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Affiliation(s)
- Francesca Seta
- Department of Pharmacology, New York Medical College, Grassland Reservation, Valhalla, NY 10595, USA
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50
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González-Périz A, Planagumà A, Gronert K, Miquel R, López-Parra M, Titos E, Horrillo R, Ferré N, Deulofeu R, Arroyo V, Rodés J, Clària J. Docosahexaenoic acid (DHA) blunts liver injury by conversion to protective lipid mediators: protectin D1 and 17S-hydroxy-DHA. FASEB J 2006; 20:2537-9. [PMID: 17056761 DOI: 10.1096/fj.06-6250fje] [Citation(s) in RCA: 172] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Docosahexaenoic acid (DHA) is a omega-3 essential fatty acid that reduces the incidence and severity of a number of diseases. Recently, a novel series of DHA-derived lipid mediators with potent protective actions has been identified. In this study we demonstrate that dietary amplification of these DHA-derived products protects the liver from necroinflammatory injury. In vitro, supplementation of hepatocytes with DHA significantly reduced hydrogen peroxide-induced DNA damage, evaluated by the "comet assay," and oxidative stress, determined by measurement of malondialdehyde levels. In vivo, dietary supplementation of mice with DHA ameliorated carbon tetrachloride-induced necroinflammatory damage. In addition, hepatic cyclooxygenase-2 expression and PGE2 levels were significantly reduced in mice fed DHA-enriched diets. In these animals, increased hepatic formation of DHA-derived lipid mediators (i.e., 17S-hydroxy-DHA (17S-HDHA) and protectin D1) was detected by HPLC-gas chromatography/mass spectrometry analysis. Consistent with these findings, synthetic 17-HDHA abrogated genotoxic and oxidative damage in hepatocytes and decreased TNF-alpha release and 5-lipoxygenase expression in macrophages. In a transactivation assay, 17-HDHA acted in a concentration-dependent manner as a PPARgamma agonist. Taken together, these findings identify a potential role for DHA-derived products, specifically 17S-HDHA and protectin D1, in mediating the protective effects of dietary DHA in necroinflammatory liver injury.
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Affiliation(s)
- Ana González-Périz
- Department of Biochemistry and Molecular Genetics, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i Sunyer, University of Barcelona School of Medicine, Barcelona 08036, Spain
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