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Komeili M, Noorbakhsh F, Esmaili J, Muhammadnejad A, Hassanzadeh G, Dehpour AR, Goudarzi R, Partoazar A. Combination therapy of phosphatidylserine liposome with cyclosporine A improves nephrotoxicity and attenuates delayed-type hypersensitivity response. Life Sci 2020; 265:118780. [PMID: 33217444 DOI: 10.1016/j.lfs.2020.118780] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 11/15/2020] [Accepted: 11/15/2020] [Indexed: 01/06/2023]
Abstract
This study aimed to evaluate the antioxidant capacity of phosphatidylserine liposome (PS) against oxidative stress due to cyclosporine A (CsA) and concurrent administration of PS and CsA on the attenuation of immune response. The effect of oral PS was evaluated on biochemical and oxidative renal markers and histopathology of nephrotic rats receiving CsA. The effect of co-administration of PS with CsA was also assessed on DTH (delayed-type hypersensitivity) reaction of immunized rats. The cytokines production level of IL-2 (Interleukin-2) and IFN-γ (Interferon gamma) was measured in immunized rat's splenocytes. PS treatment significantly (P < 0.05) reduced Cr and BUN of serum and MDA (malondialdehyde) in kidney tissue, and increased SOD (superoxide dismutase) and CAT (Catalase) of kidney tissue in CsA-nephrotic rats. Histopathology data indicated significantly (P < 0.05) nephrotoxicity improvement after 25-day treatment with PS. Furthermore, CsA plus PS administration significantly reduced DTH response and cytokines production of IL-2 and IFN-γ in immunized rats. In conclusion, coadministration of CsA plus PS may overcome oxidative stress and improve the performance of organ transplantation or autoimmune therapy.
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Affiliation(s)
- Monika Komeili
- Department of Pharmacy, Faculty of Pharmacy, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | - Farshid Noorbakhsh
- Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran 1416753955, Iran
| | - Jamileh Esmaili
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Ahad Muhammadnejad
- Cancer Biology Research Center, Cancer Institute of Iran, Tehran University of Medical Sciences, Tehran, Iran
| | - Gholamreza Hassanzadeh
- Department of Anatomy, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Ahmad Reza Dehpour
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran; Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Ramin Goudarzi
- Division of Research and Development, Pharmin USA, LLC, San Jose, USA
| | - Alireza Partoazar
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran; Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran.
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2
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Stabilin Receptors: Role as Phosphatidylserine Receptors. Biomolecules 2019; 9:biom9080387. [PMID: 31434355 PMCID: PMC6723754 DOI: 10.3390/biom9080387] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Revised: 08/16/2019] [Accepted: 08/18/2019] [Indexed: 12/18/2022] Open
Abstract
Phosphatidylserine is a membrane phospholipid that is localized to the inner leaflet of the plasma membrane. Phosphatidylserine externalization to the outer leaflet of the plasma membrane is an important signal for various physiological processes, including apoptosis, platelet activation, cell fusion, lymphocyte activation, and regenerative axonal fusion. Stabilin-1 and stabilin-2 are membrane receptors that recognize phosphatidylserine on the cell surface. Here, we discuss the functions of Stabilin-1 and stabilin-2 as phosphatidylserine receptors in apoptotic cell clearance (efferocytosis) and cell fusion, and their ligand-recognition and signaling pathways.
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3
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Crusca E, Basso LGM, Altei WF, Marchetto R. Biophysical characterization and antitumor activity of synthetic Pantinin peptides from scorpion's venom. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:2155-2165. [DOI: 10.1016/j.bbamem.2018.08.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 07/24/2018] [Accepted: 08/19/2018] [Indexed: 01/30/2023]
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Karamdad K, Law RV, Seddon JM, Brooks NJ, Ces O. Studying the effects of asymmetry on the bending rigidity of lipid membranes formed by microfluidics. Chem Commun (Camb) 2016; 52:5277-80. [PMID: 27001410 DOI: 10.1039/c5cc10307j] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
In this article we detail a robust high-throughput microfluidic platform capable of fabricating either symmetric or asymmetric giant unilamellar vesicles (GUVs) and characterise the mechanical properties of their membranes.
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Affiliation(s)
- K Karamdad
- Department of Chemistry, Imperial College London, Exhibition Road, London, SW7 2AZ, UK. and Institute of Chemical Biology, Imperial College London, Exhibition Road, London, SW7 2AZ, UK
| | - R V Law
- Department of Chemistry, Imperial College London, Exhibition Road, London, SW7 2AZ, UK. and Institute of Chemical Biology, Imperial College London, Exhibition Road, London, SW7 2AZ, UK
| | - J M Seddon
- Department of Chemistry, Imperial College London, Exhibition Road, London, SW7 2AZ, UK. and Institute of Chemical Biology, Imperial College London, Exhibition Road, London, SW7 2AZ, UK
| | - N J Brooks
- Department of Chemistry, Imperial College London, Exhibition Road, London, SW7 2AZ, UK. and Institute of Chemical Biology, Imperial College London, Exhibition Road, London, SW7 2AZ, UK
| | - O Ces
- Department of Chemistry, Imperial College London, Exhibition Road, London, SW7 2AZ, UK. and Institute of Chemical Biology, Imperial College London, Exhibition Road, London, SW7 2AZ, UK
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5
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Park SY, Yun Y, Lim JS, Kim MJ, Kim SY, Kim JE, Kim IS. Stabilin-2 modulates the efficiency of myoblast fusion during myogenic differentiation and muscle regeneration. Nat Commun 2016; 7:10871. [PMID: 26972991 PMCID: PMC4793076 DOI: 10.1038/ncomms10871] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 01/28/2016] [Indexed: 01/16/2023] Open
Abstract
Myoblast fusion is essential for the formation of skeletal muscle myofibres. Studies have shown that phosphatidylserine is necessary for myoblast fusion, but the underlying mechanism is not known. Here we show that the phosphatidylserine receptor stabilin-2 acts as a membrane protein for myoblast fusion during myogenic differentiation and muscle regeneration. Stabilin-2 expression is induced during myogenic differentiation, and is regulated by calcineurin/NFAT signalling in myoblasts. Forced expression of stabilin-2 in myoblasts is associated with increased myotube formation, whereas deficiency of stabilin-2 results in the formation of small, thin myotubes. Stab2-deficient mice have myofibres with small cross-sectional area and few myonuclei and impaired muscle regeneration after injury. Importantly, myoblasts lacking stabilin-2 have reduced phosphatidylserine-dependent fusion. Collectively, our results show that stabilin-2 contributes to phosphatidylserine-dependent myoblast fusion and provide new insights into the molecular mechanism by which phosphatidylserine mediates myoblast fusion during muscle growth and regeneration. Phosphatidylserine and its receptors are associated with cell-cell fusion. Here, the authors show the phosphatidylserine receptor stabilin-2 is expressed by muscle cells and plays a vital role in myoblast fusion and post-injury muscle regeneration in mice.
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Affiliation(s)
- Seung-Yoon Park
- Department of Biochemistry, School of Medicine, Dongguk University, Gyeongju 780-714, Republic of Korea
| | - Youngeun Yun
- Department of Biochemistry and Cell Biology, School of Medicine, Kyungpook National University, Daegu 700-422, Republic of Korea
| | - Jung-Suk Lim
- Department of Biochemistry, School of Medicine, Dongguk University, Gyeongju 780-714, Republic of Korea
| | - Mi-Jin Kim
- Department of Biochemistry, School of Medicine, Dongguk University, Gyeongju 780-714, Republic of Korea
| | - Sang-Yeob Kim
- Department of Convergence Medicine, University of Ulsan, College of Medicine &Asan Institute for Life Sciences, Asan Medical Center, Seoul 138-736, Republic of Korea
| | - Jung-Eun Kim
- Department of Molecular Medicine, School of Medicine, Kyungpook National University, Daegu 700-422, Republic of Korea
| | - In-San Kim
- Biomedical Research Institute, Korea Institute Science and Technology, Seoul 136-791, Republic of Korea.,KU-KIST school, Korea University, Seoul 136-701, Republic of Korea
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Zhang Y, Wang C, Hu R, Liu Z, Xue W. Polyethylenimine-Induced Alterations of Red Blood Cells and Their Recognition by the Complement System and Macrophages. ACS Biomater Sci Eng 2015; 1:139-147. [DOI: 10.1021/ab500128q] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Yi Zhang
- Key Laboratory of Biomaterials
of Guangdong Higher Education Institutes, Department of Biomedical
Engineering, Jinan University, Guangzhou 510632, China
| | - Changyong Wang
- Key Laboratory of Biomaterials
of Guangdong Higher Education Institutes, Department of Biomedical
Engineering, Jinan University, Guangzhou 510632, China
| | - Rushan Hu
- Key Laboratory of Biomaterials
of Guangdong Higher Education Institutes, Department of Biomedical
Engineering, Jinan University, Guangzhou 510632, China
| | - Zonghua Liu
- Key Laboratory of Biomaterials
of Guangdong Higher Education Institutes, Department of Biomedical
Engineering, Jinan University, Guangzhou 510632, China
| | - Wei Xue
- Key Laboratory of Biomaterials
of Guangdong Higher Education Institutes, Department of Biomedical
Engineering, Jinan University, Guangzhou 510632, China
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7
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Frey B, Gaipl US. The immune functions of phosphatidylserine in membranes of dying cells and microvesicles. Semin Immunopathol 2010; 33:497-516. [DOI: 10.1007/s00281-010-0228-6] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2010] [Accepted: 09/21/2010] [Indexed: 01/05/2023]
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The conserved histidine in epidermal growth factor-like domains of stabilin-2 modulates pH-dependent recognition of phosphatidylserine in apoptotic cells. Int J Biochem Cell Biol 2010; 42:1154-63. [PMID: 20382256 DOI: 10.1016/j.biocel.2010.03.024] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2009] [Revised: 03/12/2010] [Accepted: 03/31/2010] [Indexed: 11/21/2022]
Abstract
Clearance of apoptotic cells is involved in the resolution of inflammation, and this mechanism is controlled by the regulation of pro- and anti-inflammatory cytokine production during the ingestion of apoptotic cells. Inflamed areas show extracellular acidity, and low pH stimulates cellular functions of immune cells. However, little is known about the influence of extracellular acidic pH on the function of phagocytic cells. In this study, we showed that stabilin-2-mediated phagocytosis is activated in low pH media (pH 6.8) and examined the molecular mechanisms underlying this pH-dependent enhancement of phagocytic activity. Stabilin-2, which is expressed in human monocyte derived macrophages (HMDM), is a phosphatidylserine (PS) receptor that mediates phagocytosis of apoptotic cells, and releases the anti-inflammatory cytokine, TGF-beta. The PS binding activity of stabilin-2 is enhanced in low pH, and a conserved histidine(1403) in close proximity to the PS binding loop is critical for pH-dependent activity. We propose that protonation of His(1403) may rearrange the PS binding loop to enhance binding affinity in low pH, indicating that acidic pH might act as a danger signal to stimulate stabilin-2-mediated phagocytosis to resolve inflammation. Considering that phosphatidylserine is an important target molecule for apoptotic cells in the acidic microenvironment of inflammation and tumors, our results also have implications for pH sensitive targeting of apoptotic cells.
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9
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Karikoski M, Irjala H, Maksimow M, Miiluniemi M, Granfors K, Hernesniemi S, Elima K, Moldenhauer G, Schledzewski K, Kzhyshkowska J, Goerdt S, Salmi M, Jalkanen S. Clever-1/Stabilin-1 regulates lymphocyte migration within lymphatics and leukocyte entrance to sites of inflammation. Eur J Immunol 2010; 39:3477-87. [PMID: 19830743 DOI: 10.1002/eji.200939896] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Clever-1/Stabilin-1 is a scavenger receptor present on lymphatic and sinusoidal endothelium as well as on a subset of type II macrophages. It is also induced on vasculature at sites of inflammation. However, its in vivo function has remained practically unknown and this work addresses those unknown aspects. We demonstrate using in vivo models that Clever-1/Stabilin-1 mediates migration of T and B lymphocytes to the draining lymph nodes in vivo and identify the adhesive epitope of the Clever-1/Stabilin-1 molecule responsible for the interaction between lymphocytes and lymphatic endothelium. Moreover, we demonstrate that Ab blocking of Clever-1/Stabilin-1 efficiently inhibits peritonitis in mice by decreasing the entrance of granulocytes by 50%, while migration of monocytes and lymphocytes into the inflamed peritoneum is prevented almost completely. Despite efficient anti-inflammatory activity the Ab therapy does not dramatically dampen immune responses against the bacterial and foreign protein Ag tested and bacterial clearance. These results indicate that anti-Clever-1/Stabilin-1 treatment can target two different arms of the vasculature--traffic via lymphatics and inflamed blood vessels.
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Affiliation(s)
- Marika Karikoski
- MediCity and Department of Medical Microbiology and Immunology, University of Turku and National Institute of Health and Welfare, Turku, Finland
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10
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Fadeel B, Xue D. The ins and outs of phospholipid asymmetry in the plasma membrane: roles in health and disease. Crit Rev Biochem Mol Biol 2009; 44:264-77. [PMID: 19780638 DOI: 10.1080/10409230903193307] [Citation(s) in RCA: 288] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
A common feature of all eukaryotic membranes is the non-random distribution of different lipid species in the lipid bilayer (lipid asymmetry). Lipid asymmetry provides the two sides of the plasma membrane with different biophysical properties and influences numerous cellular functions. Alteration of lipid asymmetry plays a prominent role during cell fusion, activation of the coagulation cascade, and recognition and removal of apoptotic cell corpses by macrophages (programmed cell clearance). Here we discuss the origin and maintenance of phospholipid asymmetry, based on recent studies in mammalian systems as well as in Caenhorhabditis elegans and other model organisms, along with emerging evidence for a conserved role of mitochondria in the loss of lipid asymmetry during apoptosis. The functional significance of lipid asymmetry and its disruption during health and disease is also discussed.
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Affiliation(s)
- Bengt Fadeel
- Division of Molecular Toxicology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
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11
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Park SY, Kim SY, Jung MY, Bae DJ, Kim IS. Epidermal growth factor-like domain repeat of stabilin-2 recognizes phosphatidylserine during cell corpse clearance. Mol Cell Biol 2008; 28:5288-98. [PMID: 18573870 PMCID: PMC2519725 DOI: 10.1128/mcb.01993-07] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2007] [Revised: 12/03/2007] [Accepted: 06/13/2008] [Indexed: 11/20/2022] Open
Abstract
Exposure of phosphatidylserine (PS) on the cell surface occurs early during apoptosis and serves as a recognition signal for phagocytes. Clearance of apoptotic cells by a membrane PS receptor is one of the critical anti-inflammatory functions of macrophages. However, the PS binding receptors and their recognition mechanisms have not been fully investigated. Recently, we reported that stabilin-2 is a PS receptor that mediates the clearance of apoptotic cells, thus releasing the anti-inflammatory cytokine, transforming growth factor beta. In this study, we showed that epidermal growth factor (EGF)-like domain repeats (EGFrp) in stabilin-2 can directly and specifically recognize PS. The EGFrps also competitively impaired apoptotic cell uptake by macrophages in in vivo models. We also showed that calcium ions are required for stabilin-2 to mediate phagocytosis via EGFrp. Interestingly, at least four tandem repeats of EGF-like domains were required to recognize PS, and the second atypical EGF-like domain in EGFrp was critical for calcium-dependent PS recognition. Considering that PS itself is an important target molecule for both apoptotic cells and nonapoptotic cells during various cellular processes, our results should help elucidate the molecular mechanism by which apoptotic cell clearance in the human body occurs and also have implications for targeting PS externalization of nonapoptotic cells.
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Affiliation(s)
- Seung-Yoon Park
- Department of Biochemistry and Cell Biology, Cell and Matrix Research Institute, School of Medicine, Kyungpook National University, Daegu 700-422, Republic of Korea
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12
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Witasp E, Uthaisang W, Elenström-Magnusson C, Hanayama R, Tanaka M, Nagata S, Orrenius S, Fadeel B. Bridge over troubled water: milk fat globule epidermal growth factor 8 promotes human monocyte-derived macrophage clearance of non-blebbing phosphatidylserine-positive target cells. Cell Death Differ 2007; 14:1063-5. [PMID: 17256011 DOI: 10.1038/sj.cdd.4402096] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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13
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Liu ML, Reilly MP, Casasanto P, McKenzie SE, Williams KJ. Cholesterol enrichment of human monocyte/macrophages induces surface exposure of phosphatidylserine and the release of biologically-active tissue factor-positive microvesicles. Arterioscler Thromb Vasc Biol 2006; 27:430-5. [PMID: 17158353 PMCID: PMC4568121 DOI: 10.1161/01.atv.0000254674.47693.e8] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
OBJECTIVE Biologically significant amounts of two procoagulant molecules, phosphatidylserine (PS) and tissue factor (TF), are transported by monocyte/macrophage-derived microvesicles (MVs). Because cellular cholesterol accumulation is an important feature of atherosclerotic vascular disease, we now examined effects of cholesterol enrichment on MV release from human monocytes and macrophages. METHODS AND RESULTS Cholesterol enrichment of human THP-1 monocytes, alone or in combination with lipopolysaccharide (LPS), tripled their total MV generation, as quantified by flow cytometry based on particle size and PS exposure. The subset of these MVs that were also TF-positive was likewise increased by cellular cholesterol enrichment, and these TF-positive MVs exhibited a striking 10-fold increase in procoagulant activity. Moreover, cholesterol enrichment of primary human monocyte-derived macrophages also increased their total as well as TF-positive MV release, and these TF-positive MVs exhibited a similar 10-fold increase in procoagulant activity. To explore the mechanisms of enhanced MV release, we found that cholesterol enrichment of monocytes caused PS exposure on the cell surface by as early as 2 hours and genomic DNA fragmentation in a minority of cells by 20 hours. Addition of a caspase inhibitor at the beginning of these incubations blunted both cholesterol-induced apoptosis and MV release. CONCLUSIONS Cholesterol enrichment of human monocyte/macrophages induces the generation of highly biologically active, PS-positive MVs, at least in part through induction of apoptosis. Cholesterol-induced monocyte/macrophage MVs, both TF-positive and TF-negative, may be novel contributors to atherothrombosis.
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Affiliation(s)
- Ming-Lin Liu
- Dorrance H. Hamilton Research Laboratories, Division of Endocrinology, Diabetes and Metabolic Diseases, Department of Medicine, Jefferson Medical College of Thomas Jefferson University, Philadelphia, PA 19107, USA.
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Munoz LE, Franz S, Pausch F, Fürnrohr B, Sheriff A, Vogt B, Kern PM, Baum W, Stach C, von Laer D, Brachvogel B, Poschl E, Herrmann M, Gaipl US. The influence on the immunomodulatory effects of dying and dead cells of Annexin V. J Leukoc Biol 2006; 81:6-14. [PMID: 17005907 DOI: 10.1189/jlb.0306166] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Apoptotic and necrotic cells expose phosphatidylserine (PS). This membrane modification ensures a swift recognition and uptake by phagocytes of the dying and dead cells. Annexin V (AxV) preferentially binds to anionic phospholipids and thereby, modulates the clearance process. First, we analyzed the influence of AxV on the immunogenicity of apoptotic cells. The addition to apoptotic cells of AxV prior to their injection into mice increased their immunogenicity significantly. Next, we studied the influence of endogenous AxV on the allogeneic reaction against apoptotic and necrotic cells. To preserve heat-labile, short-lived "danger signals," we induced necrosis by mechanical stress. Wild-type mice showed a strong, allogeneic delayed-type hypersensitivity (DTH) reaction. In contrast, AxV-deficient animals showed almost no allogeneic DTH reaction, indicating that endogenous AxV increases the immune response against dead cells. Furthermore, AxV-deficient macrophages had a higher immunosuppressive potential in vitro. Next, we analyzed the influence of AxV on chronic macrophage infection with HIV-1, known to expose PS on its surface. The infectivity in human macrophages of HIV-1 was reduced significantly in the presence of AxV. Finally, we show that AxV also blocked the in vitro uptake by macrophages of primary necrotic cells. Similar to apoptotic cells, necrotic cells generated by heat treatment displayed an anti-inflammatory activity. In contrast, mechanical stress-induced necrotic cells led to a decreased secretion of IL-10, indicating a more inflammatory potential. From the experiments presented above, we conclude that AxV influences the clearance of several PS-exposing particles such as viruses, dying, and dead cells.
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Affiliation(s)
- Luis E Munoz
- Institute for Clinical Immunology, Department of Internal Medicne 3, Friedrich-Alexander-University of Erlangen-Nuremberg, Glueckstrasse 4a, 91054 Erlangen, Germany
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15
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Bayir H, Fadeel B, Palladino MJ, Witasp E, Kurnikov IV, Tyurina YY, Tyurin VA, Amoscato AA, Jiang J, Kochanek PM, DeKosky ST, Greenberger JS, Shvedova AA, Kagan VE. Apoptotic interactions of cytochrome c: redox flirting with anionic phospholipids within and outside of mitochondria. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2006; 1757:648-59. [PMID: 16740248 DOI: 10.1016/j.bbabio.2006.03.002] [Citation(s) in RCA: 143] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2005] [Revised: 02/17/2006] [Accepted: 03/06/2006] [Indexed: 11/26/2022]
Abstract
Since the (re)discovery of cytochrome c (cyt c) in the early 1920s and subsequent detailed characterization of its structure and function in mitochondrial electron transport, it took over 70 years to realize that cyt c plays a different, not less universal role in programmed cell death, apoptosis, by interacting with several proteins and forming apoptosomes. Recently, two additional essential functions of cyt c in apoptosis have been discovered that are carried out via its interactions with anionic phospholipids: a mitochondria specific phospholipid, cardiolipin (CL), and plasma membrane phosphatidylserine (PS). Execution of apoptotic program in cells is accompanied by substantial and early mitochondrial production of reactive oxygen species (ROS). Because antioxidant enhancements protect cells against apoptosis, ROS production was viewed not as a meaningless side effect of mitochondrial disintegration but rather playing some - as yet unidentified - role in apoptosis. This conundrum has been resolved by establishing that mitochondria contain a pool of cyt c, which interacts with CL and acts as a CL oxygenase. The oxygenase is activated during apoptosis, utilizes generated ROS and causes selective oxidation of CL. The oxidized CL is required for the release of pro-apoptotic factors from mitochondria into the cytosol. This redox mechanism of cyt c is realized earlier than its other well-recognized functions in the formation of apoptosomes and caspase activation. In the cytosol, released cyt c interacts with another anionic phospholipid, PS, and catalyzes its oxidation in a similar oxygenase reaction. Peroxidized PS facilitates its externalization essential for the recognition and clearance of apoptotic cells by macrophages. Redox catalysis of plasma membrane PS oxidation constitutes an important redox-dependent function of cyt c in apoptosis and phagocytosis. Thus, cyt c acts as an anionic phospholipid specific oxygenase activated and required for the execution of essential stages of apoptosis. This review is focused on newly discovered redox mechanisms of complexes of cyt c with anionic phospholipids and their role in apoptotic pathways in health and disease.
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Affiliation(s)
- H Bayir
- Center for Free Radical and Antioxidant Health, Pittsburgh, PA 15219, USA.
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