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Parra LG, Erjavec LC, Casali CI, Zerpa Velazquez A, Weber K, Setton-Avruj CP, Fernández Tome MDC. Cytosolic phospholipase A 2 regulates lipid homeostasis under osmotic stress through PPARγ. FEBS J 2024; 291:722-743. [PMID: 37947039 DOI: 10.1111/febs.16998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 10/03/2023] [Accepted: 10/20/2023] [Indexed: 11/12/2023]
Abstract
Physiologically, renal medullary cells are surrounded by a hyperosmolar interstitium. However, different pathological situations can induce abrupt changes in environmental osmolality, causing cell stress. Therefore, renal cells must adapt to survive in this new condition. We previously demonstrated that, among the mechanisms involved in osmoprotection, renal cells upregulate triglyceride biosynthesis (which helps preserve glycerophospholipid synthesis and membrane homeostasis) and cyclooxygenase-2 (which generates prostaglandins from arachidonic acid) to maintain lipid metabolism in renal tissue. Herein, we evaluated whether hyperosmolality modulates phospholipase A2 (PLA2 ) activity, leading to arachidonic acid release from membrane glycerophospholipid, and investigated its possible role in hyperosmolality-induced triglyceride synthesis and accumulation. We found that hyperosmolality induced PLA2 expression and activity in Madin-Darby canine kidney cells. Cytosolic PLA2 (cPLA2) inhibition, but not secreted or calcium-independent PLA2 (sPLA2 or iPLA2 , respectively), prevented triglyceride synthesis and reduced cell survival. Inhibition of prostaglandin synthesis with indomethacin not only failed to prevent hyperosmolality-induced triglyceride synthesis but also exacerbated it. Similar results were observed with the peroxisomal proliferator activated receptor gamma (PPARγ) agonist rosiglitazone. Furthermore, hyperosmolality increased free intracellular arachidonic acid levels, which were even higher when prostaglandin synthesis was inhibited by indomethacin. Blocking PPARγ with GW-9662 prevented the effects of both indomethacin and rosiglitazone on triglyceride synthesis and even reduced hyperosmolality-induced triglyceride synthesis, suggesting that arachidonic acid may stimulate triglyceride synthesis through PPARγ activation. These results highlight the role of cPLA2 in osmoprotection, since it is essential to provide arachidonic acid, which is involved in PPARγ-regulated triglyceride synthesis, thus guaranteeing cell survival.
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Affiliation(s)
- Leandro Gastón Parra
- Departamento de Ciencias Biológicas, Cátedra de Biología Celular y Molecular, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Argentina
- Instituto de Química y Fisicoquímica Biológicas Prof. Dr. Alejandro C. Paladini (IQUIFIB)-Facultad de Farmacia y Bioquímica, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
| | - Luciana Cecilia Erjavec
- Departamento de Ciencias Biológicas, Cátedra de Biología Celular y Molecular, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Argentina
- Instituto de Química y Fisicoquímica Biológicas Prof. Dr. Alejandro C. Paladini (IQUIFIB)-Facultad de Farmacia y Bioquímica, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
| | - Cecilia Irene Casali
- Departamento de Ciencias Biológicas, Cátedra de Biología Celular y Molecular, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Argentina
- Instituto de Química y Fisicoquímica Biológicas Prof. Dr. Alejandro C. Paladini (IQUIFIB)-Facultad de Farmacia y Bioquímica, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
| | - Andrea Zerpa Velazquez
- Departamento de Ciencias Biológicas, Cátedra de Biología Celular y Molecular, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Argentina
| | - Karen Weber
- Departamento de Ciencias Biológicas, Cátedra de Biología Celular y Molecular, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Argentina
| | - Clara Patricia Setton-Avruj
- Instituto de Química y Fisicoquímica Biológicas Prof. Dr. Alejandro C. Paladini (IQUIFIB)-Facultad de Farmacia y Bioquímica, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
- Departaemento de Química Biológica, Cátedra de Química Biológica Patológica, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Argentina
| | - María Del Carmen Fernández Tome
- Departamento de Ciencias Biológicas, Cátedra de Biología Celular y Molecular, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Argentina
- Instituto de Química y Fisicoquímica Biológicas Prof. Dr. Alejandro C. Paladini (IQUIFIB)-Facultad de Farmacia y Bioquímica, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
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Murakami M, Sato H, Taketomi Y. Modulation of immunity by the secreted phospholipase A 2 family. Immunol Rev 2023; 317:42-70. [PMID: 37035998 DOI: 10.1111/imr.13205] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 03/23/2023] [Accepted: 03/28/2023] [Indexed: 04/11/2023]
Abstract
Among the phospholipase A2 (PLA2 ) superfamily, which typically catalyzes the sn-2 hydrolysis of phospholipids to yield fatty acids and lysophospholipids, the secreted PLA2 (sPLA2 ) family contains 11 isoforms in mammals. Individual sPLA2 s have unique enzymatic specificity toward fatty acids and polar heads of phospholipid substrates and display distinct tissue/cellular distributions, suggesting their distinct physiological functions. Recent studies using knockout and/or transgenic mice for a full set of sPLA2 s have revealed their roles in modulation of immunity and related disorders. Application of mass spectrometric lipidomics to these mice has enabled to identify target substrates and products of individual sPLA2 s in given tissue microenvironments. sPLA2 s hydrolyze not only phospholipids in the plasma membrane of activated, damaged or dying mammalian cells, but also extracellular phospholipids such as those in extracellular vesicles, microbe membranes, lipoproteins, surfactants, and dietary phospholipids, thereby exacerbating or ameliorating various diseases. The actions of sPLA2 s are dependent on, or independent of, the generation of fatty acid- or lysophospholipid-derived lipid mediators according to the pathophysiological contexts. In this review, we make an overview of our current understanding of the roles of individual sPLA2 s in various immune responses and associated diseases.
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Affiliation(s)
- Makoto Murakami
- Laboratory of Microenvironmental and Metabolic Health Science, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
- AMED-CREST, Japan Agency for Medical Research and Development, Tokyo, Japan
| | - Hiroyasu Sato
- Laboratory of Microenvironmental and Metabolic Health Science, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Yoshitaka Taketomi
- Laboratory of Microenvironmental and Metabolic Health Science, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
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3
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Gharpure SJ, Jegadeesan S, Vishwakarma DS. Total synthesis of myristinins A–F and 3′-hydroxy-5,7-dimethoxy-4- O-2′-cycloflavan by iterative generation of o-quinone methides. NEW J CHEM 2022. [DOI: 10.1039/d2nj00244b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An iterative generation of o-quinone methides (o-QMs) and [4+2] cycloaddition followed by inter/intra-molecular Michael addition in a cascade sequence gave expedient access to the total synthesis of myristinins A–F and 3′-hydroxy-5,7-dimethoxy-4-O-2′-cycloflavan and their analogues, respectively.
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Affiliation(s)
- Santosh J. Gharpure
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai – 400076, India
| | - S. Jegadeesan
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai – 400076, India
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4
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Gharpure SJ, Jegadeesan S, Vishwakarma DS. Acid-catalysed iterative generation of o-quinone methides for the synthesis of dioxabicyclo[3.3.1]nonanes: total synthesis of myristicyclins A-B. Chem Commun (Camb) 2021; 57:13333-13336. [PMID: 34816832 DOI: 10.1039/d1cc06146a] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report a practical and efficient method for the synthesis of bioactive flavanoids relying on the strategic use of o-quinine methide (o-QM) intermediates. This involves Brønsted acid-catalysed iterative generation of o-QMs/[4+2] cycloaddition/intermolecular Michael addition/cyclative acetalization in a cascade sequence for the synthesis of dioxabicyclo[3.3.1]nonanes. The 'one-pot', controlled cascade sequence successfully provided the shortest route amenable for gram scale synthesis of natural products (±)-myristicyclins A-B.
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Affiliation(s)
- Santosh J Gharpure
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
| | - S Jegadeesan
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
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5
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Filkin SY, Lipkin AV, Fedorov AN. Phospholipase Superfamily: Structure, Functions, and Biotechnological Applications. BIOCHEMISTRY (MOSCOW) 2020; 85:S177-S195. [DOI: 10.1134/s0006297920140096] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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6
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Zhang S, Li Y, Qin Z, Tu G, Chen G, Yan A. SAR study on inhibitors of GIIA secreted phospholipase A
2
using machine learning methods. Chem Biol Drug Des 2019; 93:666-684. [DOI: 10.1111/cbdd.13470] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 12/14/2018] [Accepted: 12/17/2018] [Indexed: 12/24/2022]
Affiliation(s)
- Shengde Zhang
- State Key Laboratory of Chemical Resource EngineeringDepartment of Pharmaceutical EngineeringBeijing University of Chemical Technology Beijing China
| | - Yang Li
- Institute of Science and TechnologyShandong University of Traditional Chinese Medicine Ji'nan Shandong China
| | - Zijian Qin
- State Key Laboratory of Chemical Resource EngineeringDepartment of Pharmaceutical EngineeringBeijing University of Chemical Technology Beijing China
| | - Guipin Tu
- State Key Laboratory of Chemical Resource EngineeringDepartment of Pharmaceutical EngineeringBeijing University of Chemical Technology Beijing China
| | - Guang Chen
- College of Life Science and TechnologyBeijing University of Chemical Technology Beijing China
| | - Aixia Yan
- State Key Laboratory of Chemical Resource EngineeringDepartment of Pharmaceutical EngineeringBeijing University of Chemical Technology Beijing China
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7
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Allen EE, Zhu C, Panek JS, Schaus SE. Multicomponent Condensation Reactions via ortho-Quinone Methides. Org Lett 2017; 19:1878-1881. [PMID: 28357870 DOI: 10.1021/acs.orglett.7b00647] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Iron(III) salts promote the condensation of aldehydes or acetals with electron-rich phenols to generate ortho-quinone methides that undergo Diels-Alder condensations with alkenes. The reaction sequence occurs in a single vessel to afford benzopyrans in up to 95% yield. The reaction was discovered while investigating a two-component strategy using 2-(hydroxy(phenyl)methyl)phenols to access the desired ortho-quinone methide in a Diels-Alder condensation. The two-component condensation also afforded the corresponding benzopyran products in yields up to 97%. Taken together, the two- and three-component strategies using ortho-quinone methide intermediates provide efficient access to benzopyrans in good yields and selectivities.
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Affiliation(s)
- Emily E Allen
- Department of Chemistry, Center for Molecular Discovery (BU-CMD), Life Science and Engineering Building, Boston University , 24 Cummington Mall, Boston, Massachusetts 02215, United States
| | - Calvin Zhu
- Department of Chemistry, Center for Molecular Discovery (BU-CMD), Life Science and Engineering Building, Boston University , 24 Cummington Mall, Boston, Massachusetts 02215, United States
| | - James S Panek
- Department of Chemistry, Center for Molecular Discovery (BU-CMD), Life Science and Engineering Building, Boston University , 24 Cummington Mall, Boston, Massachusetts 02215, United States
| | - Scott E Schaus
- Department of Chemistry, Center for Molecular Discovery (BU-CMD), Life Science and Engineering Building, Boston University , 24 Cummington Mall, Boston, Massachusetts 02215, United States
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8
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A one-pot oxidation/cycloaddition cascade synthesis of 2,4-diaryl chromans via ortho-quinone methides. Tetrahedron 2016. [DOI: 10.1016/j.tet.2015.12.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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9
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Quach ND, Arnold RD, Cummings BS. Secretory phospholipase A2 enzymes as pharmacological targets for treatment of disease. Biochem Pharmacol 2014; 90:338-48. [PMID: 24907600 DOI: 10.1016/j.bcp.2014.05.022] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 05/28/2014] [Accepted: 05/28/2014] [Indexed: 02/03/2023]
Abstract
Phospholipase A2 (PLA2) cleave phospholipids preferentially at the sn-2 position, liberating free fatty acids and lysophospholipids. They are classified into six main groups based on size, location, function, substrate specificity and calcium requirement. These classes include secretory PLA2 (sPLA2), cytosolic (cPLA2), Ca(2+)-independent (iPLA2), platelet activating factor acetylhydrolases (PAF-AH), lysosomal PLA2 (LyPLA2) and adipose specific PLA2 (AdPLA2). It is hypothesized that PLA2 can serve as pharmacological targets for the therapeutic treatment of several diseases, including cardiovascular diseases, atherosclerosis, immune disorders and cancer. Special emphasis has been placed on inhibitors of sPLA2 isoforms as pharmacological moieties, mostly due to the fact that these enzymes are activated during inflammatory events and because their expression is increased in several diseases. This review focuses on understanding how sPLA2 isoform expression is altered during disease progression and the possible therapeutic interventions to specifically target sPLA2 isoforms, including new approaches using nano-particulate-based strategies.
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Affiliation(s)
- Nhat D Quach
- Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, GA 30602, United States
| | - Robert D Arnold
- Department of Drug Discovery & Development, Harrison School of Pharmacy, Auburn University, Auburn, AL 36849-5503, United States
| | - Brian S Cummings
- Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, GA 30602, United States.
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Gharpure SJ, Sathiyanarayanan AM, Vuram PK. Hetero Diels–Alder reaction of olefin with o-quinone methides generated using (±)-binolphosphoric acid for the stereoselective synthesis of 2,4-diarylbenzopyrans: application to the formal synthesis of myristinin B/C. RSC Adv 2013. [DOI: 10.1039/c3ra43526a] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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11
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Oslund RC, Gelb MH. Biochemical characterization of selective inhibitors of human group IIA secreted phospholipase A(2) and hyaluronic acid-linked inhibitor conjugates. Biochemistry 2012; 51:8617-26. [PMID: 23020658 DOI: 10.1021/bi301140b] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
We explored the inhibition mode of group IIA secreted phospholipase A(2) (GIIA sPLA(2)) selective inhibitors and tested their ability to inhibit GIIA sPLA(2) activity as chemical conjugates with hyaluronic acid (HA). Analogues of a benzo-fused indole sPLA(2) inhibitor were developed in which the carboxylate group on the inhibitor scaffold, which has been shown to coordinate to a Ca(2+) ligand in the enzyme active site, was replaced with other functionality. Replacing the carboxylate group with amine, amide, or hydroxyl groups had no effect on human GIIA (hGIIA) sPLA(2) inhibition potency but dramatically lowered inhibition potency against hGV and hGX sPLA(2)s. An alkylation protection assay was used to probe active site binding of carboxylate and noncarboxylate inhibitors in the presence and absence of Ca(2+) and/or lipid vesicles. We observed that carboxylate-containing inhibitors bind the hGIIA sPLA(2) active site with low nanomolar affinity, but only when Ca(2+) is present. Noncarboxylate, GIIA sPLA(2) selective inhibitors also bind the hGIIA sPLA(2) active site in the nanomolar range. However, binding for GIIA sPLA(2) selective inhibitors was dependent on the presence of a lipid membrane and not Ca(2+). These results indicate that GIIA sPLA(2) selective inhibitors exert their inhibitory effects by binding to the hGIIA sPLA(2) active site. An HA-linked GIIA inhibitor conjugate was developed using peptide coupling conditions and found to be less potent and selective against hGIIA sPLA(2) than the unconjugated inhibitor. Compounds reported in this study are some of the most potent and selective GIIA sPLA(2) active site binding inhibitors reported to date.
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Affiliation(s)
- Rob C Oslund
- Departments of Chemistry and Biomolecular Structure and Design, University of Washington, Seattle, WA 98195, USA
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12
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Ahn JH, Liu Q, Lee C, Ahn MJ, Yoo HS, Hwang BY, Lee MK. A new pancreatic lipase inhibitor from Broussonetia kanzinoki. Bioorg Med Chem Lett 2012; 22:2760-3. [DOI: 10.1016/j.bmcl.2012.02.088] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2011] [Revised: 02/13/2012] [Accepted: 02/27/2012] [Indexed: 10/28/2022]
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13
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Dennis EA, Cao J, Hsu YH, Magrioti V, Kokotos G. Phospholipase A2 enzymes: physical structure, biological function, disease implication, chemical inhibition, and therapeutic intervention. Chem Rev 2011; 111:6130-85. [PMID: 21910409 PMCID: PMC3196595 DOI: 10.1021/cr200085w] [Citation(s) in RCA: 820] [Impact Index Per Article: 63.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Edward A. Dennis
- Department of Chemistry and Biochemistry and Pharmacology, School of Medicine, University of California, San Diego, La Jolla, California 92093-0601
| | - Jian Cao
- Department of Chemistry and Biochemistry and Pharmacology, School of Medicine, University of California, San Diego, La Jolla, California 92093-0601
| | - Yuan-Hao Hsu
- Department of Chemistry and Biochemistry and Pharmacology, School of Medicine, University of California, San Diego, La Jolla, California 92093-0601
| | - Victoria Magrioti
- Laboratory of Organic Chemistry, Department of Chemistry, University of Athens, Panepistimiopolis, Athens 15771, Greece
| | - George Kokotos
- Laboratory of Organic Chemistry, Department of Chemistry, University of Athens, Panepistimiopolis, Athens 15771, Greece
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Murakami M, Taketomi Y, Miki Y, Sato H, Hirabayashi T, Yamamoto K. Recent progress in phospholipase A₂ research: from cells to animals to humans. Prog Lipid Res 2010; 50:152-92. [PMID: 21185866 DOI: 10.1016/j.plipres.2010.12.001] [Citation(s) in RCA: 368] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Mammalian genomes encode genes for more than 30 phospholipase A₂s (PLA₂s) or related enzymes, which are subdivided into several classes including low-molecular-weight secreted PLA₂s (sPLA₂s), Ca²+-dependent cytosolic PLA₂s (cPLA₂s), Ca²+-independent PLA₂s (iPLA₂s), platelet-activating factor acetylhydrolases (PAF-AHs), lysosomal PLA₂s, and a recently identified adipose-specific PLA. Of these, the intracellular cPLA₂ and iPLA₂ families and the extracellular sPLA₂ family are recognized as the "big three". From a general viewpoint, cPLA₂α (the prototypic cPLA₂ plays a major role in the initiation of arachidonic acid metabolism, the iPLA₂ family contributes to membrane homeostasis and energy metabolism, and the sPLA₂ family affects various biological events by modulating the extracellular phospholipid milieus. The cPLA₂ family evolved along with eicosanoid receptors when vertebrates first appeared, whereas the diverse branching of the iPLA₂ and sPLA₂ families during earlier eukaryote development suggests that they play fundamental roles in life-related processes. During the past decade, data concerning the unexplored roles of various PLA₂ enzymes in pathophysiology have emerged on the basis of studies using knockout and transgenic mice, the use of specific inhibitors, and information obtained from analysis of human diseases caused by mutations in PLA₂ genes. This review focuses on current understanding of the emerging biological functions of PLA₂s and related enzymes.
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Affiliation(s)
- Makoto Murakami
- Lipid Metabolism Project, The Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan.
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Kitsiouli E, Nakos G, Lekka ME. Phospholipase A2 subclasses in acute respiratory distress syndrome. Biochim Biophys Acta Mol Basis Dis 2009; 1792:941-53. [PMID: 19577642 DOI: 10.1016/j.bbadis.2009.06.007] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2009] [Revised: 06/25/2009] [Accepted: 06/25/2009] [Indexed: 01/12/2023]
Abstract
Phospholipases A2 (PLA2) catalyse the cleavage of fatty acids esterified at the sn-2 position of glycerophospholipids. In acute lung injury-acute respiratory distress syndrome (ALI-ARDS) several distinct isoenzymes appear in lung cells and fluid. Some are capable to trigger molecular events leading to enhanced inflammation and lung damage and others have a role in lung surfactant recycling preserving lung function: Secreted forms (groups sPLA2-IIA, -V, -X) can directly hydrolyze surfactant phospholipids. Cytosolic PLA2 (cPLA2-IVA) requiring Ca2+ has a preference for arachidonate, the precursor of eicosanoids which participate in the inflammatory response in the lung. Ca(2+)-independent intracellular PLA2s (iPLA2) take part in surfactant phospholipids turnover within alveolar cells. Acidic Ca(2+)-independent PLA2 (aiPLA2), of lysosomal origin, has additionally antioxidant properties, (peroxiredoxin VI activity), and participates in the formation of dipalmitoyl-phosphatidylcholine in lung surfactant. PAF-AH degrades PAF, a potent mediator of inflammation, and oxidatively fragmented phospholipids but also leads to toxic metabolites. Therefore, the regulation of PLA2 isoforms could be a valuable approach for ARDS treatment.
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Affiliation(s)
- Eirini Kitsiouli
- Department of Biological Applications and Technologies, School of Sciences and Technologies, University of Ioannina, Greece
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