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Alemán OR, Mora N, Rosales C. The Antibody Receptor Fc Gamma Receptor IIIb Induces Calcium Entry via Transient Receptor Potential Melastatin 2 in Human Neutrophils. Front Immunol 2021; 12:657393. [PMID: 34054821 PMCID: PMC8155622 DOI: 10.3389/fimmu.2021.657393] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 04/23/2021] [Indexed: 11/13/2022] Open
Abstract
Human neutrophils express two unique antibody receptors for IgG, the FcγRIIa and the FcγRIIIb. FcγRIIa contains an immunoreceptor tyrosine-based activation motif (ITAM) sequence within its cytoplasmic tail, which is important for initiating signaling. In contrast, FcγRIIIb is a glycosylphosphatidylinositol (GPI)-linked receptor with no cytoplasmic tail. Although, the initial signaling mechanism for FcγRIIIb remains unknown, it is clear that both receptors are capable of initiating distinct neutrophil cellular functions. For example, FcγRIIa is known to induce an increase in L-selectin expression and efficient phagocytosis, while FcγRIIIb does not promote these responses. In contrast, FcγRIIIb has been reported to induce actin polymerization, activation of β1 integrins, and formation of neutrophils extracellular traps (NET) much more efficiently than FcγRIIa. Another function where these receptors seem to act differently is the increase of cytoplasmic calcium concentration. It has been known for a long time that FcγRIIa induces production of inositol triphosphate (IP3) to release calcium from intracellular stores, while FcγRIIIb does not use this phospholipid. Thus, the mechanism for FcγRIIIb-mediated calcium rise remains unknown. Transient Receptor Potential Melastatin 2 (TRPM2) is a calcium permeable channel expressed in many cell types including vascular smooth cells, endothelial cells and leukocytes. TRPM2 can be activated by protein kinase C (PKC) and by oxidative stress. Because we previously found that FcγRIIIb stimulation leading to NET formation involves PKC activation and reactive oxygen species (ROS) production, in this report we explored whether TRPM2 is activated via FcγRIIIb and mediates calcium rise in human neutrophils. Calcium rise was monitored after Fcγ receptors were stimulated by specific monoclonal antibodies in Fura-2-loaded neutrophils. The bacterial peptide fMLF and FcγRIIa induced a calcium rise coming initially from internal pools. In contrast, FcγRIIIb caused a calcium rise by inducing calcium entry from the extracellular medium. In addition, in the presence of 2-aminoethoxydiphenyl borate (2-APB) or of clotrimazole, two inhibitors of TRPM2, FcγRIIIb-induced calcium rise was blocked. fMLF- or FcγRIIa-induced calcium rise was not affected by these inhibitors. These data suggest for the first time that FcγRIIIb aggregation activates TRPM2, to induce an increase in cytoplasmic calcium concentration through calcium internalization in human neutrophils.
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Affiliation(s)
| | | | - Carlos Rosales
- Departamento de Inmunología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, Mexico
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Mei H, Tao Y, Zhang T, Qi F. Emodin alleviates LPS-induced inflammatory response in lung injury rat by affecting the function of granulocytes. J Inflamm (Lond) 2020; 17:26. [PMID: 32782444 PMCID: PMC7414666 DOI: 10.1186/s12950-020-00252-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 07/30/2020] [Indexed: 01/21/2023] Open
Abstract
Background Acute lung injury (ALI) and/or acute respiratory distress syndrome (ARDS) are critical life-threatening syndromes characterized by the infiltration of a large number of granulocytes (mainly neutrophils) that lead to an excessive inflammatory response. Emodin (Emo) is a naturally occurring anthraquinone derivative and an active ingredient of Chinese medicine. It is believed to have anti-inflammatory effects. In this study, we examined the impact of Emo on the pulmonary inflammatory response and the granulocytes function in a rat model of lipopolysaccharide (LPS)-induced ALI. Results Treatment with Emo protected rat against LPS-induced ALI. Compared to untreated rat, Emo-treated rat exhibited significantly ameliorated lung pathological changes and decreased tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β). However, Emo has no protective effect on the rat model of acute lung injury with granulocyte deficiency. In addition, treatment with Emo enhanced the bactericidal capacity of LPS-induced granulocytes via the up-regulation of the ability of granulocytes to phagocytize bacteria and generate neutrophil extracellular traps (NETs). Emo also downregulated the respiratory burst and the expression of reactive oxygen species (ROS) in LPS-stimulated granulocytes, alleviating the damage of granulocytes to surrounding tissues. Finally, Emo can accelerate the resolution of inflammation by promoting apoptosis of granulocytes. Conclusion Our results provide the evidence that Emo could ameliorates LPS-induced ALI via its anti-inflammatory action by modulating the function of granulocytes. Emo may be a promising preventive and therapeutic agent in the treatment of ALI.
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Affiliation(s)
- Hongxia Mei
- Department of Anesthesiology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250012 Shandong Province China.,Department of Anesthesiology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, 325000 Zhejiang Province China
| | - Ying Tao
- Department of Anesthesiology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, 325000 Zhejiang Province China
| | - Tianhao Zhang
- Department of Anesthesiology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, 325000 Zhejiang Province China
| | - Feng Qi
- Department of Anesthesiology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250012 Shandong Province China
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Abstract
The superoxide (O2·-)-generating NADPH oxidase complex of phagocytes comprises a membrane-associated heterodimeric flavocytochrome, known as cytochrome b 558 (consisting of NOX2 and p22phox) and four cytosolic regulatory proteins, p47phox, p67phox, p40phox, and the small GTPase Rac. Under physiological conditions, in the resting phagocyte, O2·- generation is initiated by engagement of membrane receptors by a variety of stimuli, followed by signal transduction sequences leading to the translocation of the cytosolic components to the membrane and their association with the cytochrome, a process known as NADPH oxidase assembly. A consequent conformational change in NOX2 initiates the electron flow along a redox gradient, from NADPH to molecular oxygen (O2), leading to the one-electron reduction of O2 to O2·-. Historically, methodological difficulties in the study of the assembled complex derived from stimulated cells, due to its lack of stability, led to the design of "cell-free" systems (also known as "broken cells" or in vitro systems). In a major paradigm shift, the cell-free systems have as their starting point NADPH oxidase components derived from resting (unstimulated) phagocytes, or as in the predominant method at present, recombinant proteins representing the components of the NADPH oxidase complex. In cell-free systems, membrane receptor stimulation and the signal transduction sequence are absent, the accent being placed on the actual process of assembly, all of which takes place in vitro. Thus, a mixture of the individual components of the NADPH oxidase is exposed in vitro to an activating agent, the most common being anionic amphiphiles, resulting in the formation of a complex between cytochrome b 558 and the cytosolic components and O2·- generation in the presence of NADPH. Alternative activating pathways require posttranslational modification of oxidase components or modifying the phospholipid milieu surrounding cytochrome b 558. Activation is commonly quantified by measuring the primary product of the reaction, O2·-, trapped immediately after its generation by an appropriate acceptor in a kinetic assay, permitting the calculation of rates of O2·- production, but numerous variations exist, based on the assessment of reaction products or the consumption of substrates. Cell-free assays played a paramount role in the identification and characterization of the components of the NADPH oxidase complex, the performance of structure-function studies, the deciphering of the mechanisms of assembly, the search for inhibitory drugs, and the diagnosis of various forms of chronic granulomatous disease (CGD).
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Das A, Anbu N, SK M, Dhakshinamoorthy A, Biswas S. A functionalized UiO-66 MOF for turn-on fluorescence sensing of superoxide in water and efficient catalysis for Knoevenagel condensation. Dalton Trans 2019; 48:17371-17380. [DOI: 10.1039/c9dt03638e] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A MOF based sensor is reported for specific, rapid, and sensitive sensing of O2·− and effective and recyclable catalysis of Knoevenagel condensation.
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Affiliation(s)
- Aniruddha Das
- Department of Chemistry
- Indian Institute of Technology Guwahati
- 781039 Assam
- India
| | - Nagaraj Anbu
- School of Chemistry
- Madurai Kamaraj University
- Madurai 625021
- India
| | - Mostakim SK
- Department of Chemistry
- Indian Institute of Technology Guwahati
- 781039 Assam
- India
| | | | - Shyam Biswas
- Department of Chemistry
- Indian Institute of Technology Guwahati
- 781039 Assam
- India
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El-Benna J, Hurtado-Nedelec M, Marzaioli V, Marie JC, Gougerot-Pocidalo MA, Dang PMC. Priming of the neutrophil respiratory burst: role in host defense and inflammation. Immunol Rev 2017; 273:180-93. [PMID: 27558335 DOI: 10.1111/imr.12447] [Citation(s) in RCA: 286] [Impact Index Per Article: 40.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Neutrophils are the major circulating white blood cells in humans. They play an essential role in host defense against pathogens. In healthy individuals, circulating neutrophils are in a dormant state with very low efficiency of capture and arrest on the quiescent endothelium. Upon infection and subsequent release of pro-inflammatory mediators, the vascular endothelium signals to circulating neutrophils to roll, adhere, and cross the endothelial barrier. Neutrophils migrate toward the infection site along a gradient of chemo-attractants, then recognize and engulf the pathogen. To kill this pathogen entrapped inside the vacuole, neutrophils produce and release high quantities of antibacterial peptides, proteases, and reactive oxygen species (ROS). The robust ROS production is also called 'the respiratory burst', and the NADPH oxidase or NOX2 is the enzyme responsible for the production of superoxide anion, leading to other ROS. In vitro, several soluble and particulate agonists induce neutrophil ROS production. This process can be enhanced by prior neutrophil treatment with 'priming' agents, which alone do not induce a respiratory burst. In this review, we will describe the priming process and discuss the beneficial role of controlled neutrophil priming in host defense and the detrimental effect of excessive neutrophil priming in inflammatory diseases.
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Affiliation(s)
- Jamel El-Benna
- INSERM-U1149, CNRS-ERL8252, Centre de Recherche sur l'Inflammation, Paris, France.,Sorbonne Paris Cité, Laboratoire d'Excellence Inflamex, DHU FIRE, Faculté de Médecine, Site Xavier Bichat, Université Paris Diderot, Paris, France
| | - Margarita Hurtado-Nedelec
- INSERM-U1149, CNRS-ERL8252, Centre de Recherche sur l'Inflammation, Paris, France.,Sorbonne Paris Cité, Laboratoire d'Excellence Inflamex, DHU FIRE, Faculté de Médecine, Site Xavier Bichat, Université Paris Diderot, Paris, France.,Département d'Immunologie et d'Hématologie, UF Dysfonctionnements Immunitaires, HUPNVS, Hôpital Bichat, Paris, France
| | - Viviana Marzaioli
- INSERM-U1149, CNRS-ERL8252, Centre de Recherche sur l'Inflammation, Paris, France.,Sorbonne Paris Cité, Laboratoire d'Excellence Inflamex, DHU FIRE, Faculté de Médecine, Site Xavier Bichat, Université Paris Diderot, Paris, France
| | - Jean-Claude Marie
- INSERM-U1149, CNRS-ERL8252, Centre de Recherche sur l'Inflammation, Paris, France.,Sorbonne Paris Cité, Laboratoire d'Excellence Inflamex, DHU FIRE, Faculté de Médecine, Site Xavier Bichat, Université Paris Diderot, Paris, France.,Département d'Immunologie et d'Hématologie, UF Dysfonctionnements Immunitaires, HUPNVS, Hôpital Bichat, Paris, France
| | - Marie-Anne Gougerot-Pocidalo
- INSERM-U1149, CNRS-ERL8252, Centre de Recherche sur l'Inflammation, Paris, France.,Sorbonne Paris Cité, Laboratoire d'Excellence Inflamex, DHU FIRE, Faculté de Médecine, Site Xavier Bichat, Université Paris Diderot, Paris, France.,Département d'Immunologie et d'Hématologie, UF Dysfonctionnements Immunitaires, HUPNVS, Hôpital Bichat, Paris, France
| | - Pham My-Chan Dang
- INSERM-U1149, CNRS-ERL8252, Centre de Recherche sur l'Inflammation, Paris, France.,Sorbonne Paris Cité, Laboratoire d'Excellence Inflamex, DHU FIRE, Faculté de Médecine, Site Xavier Bichat, Université Paris Diderot, Paris, France
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