1
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Zhou Y, Nomigni MT, Gaigneaux A, Tolle F, Wright HL, Bueb JL, Bréchard S. miRNA-132-5p mediates a negative feedback regulation of IL-8 secretion through S100A8/A9 downregulation in neutrophil-like HL-60 cells. Front Immunol 2024; 14:1274378. [PMID: 38292491 PMCID: PMC10824955 DOI: 10.3389/fimmu.2023.1274378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 12/19/2023] [Indexed: 02/01/2024] Open
Abstract
Background Neutrophils are an important source of pro-inflammatory and immunomodulatory cytokines. This makes neutrophils efficient drivers of interactions with immune and non-immune cells to maintain homeostasis and modulate the inflammatory process by notably regulating the release of cytokines. Ca2+-dependent regulatory mechanism encompassing cytokine secretion by neutrophils are not still identified. In this context, we propose to define new insights on the role of Ca2+-binding proteins S100A8/A9 and on the regulatory role of miRNA-132-5p, which was identified as a regulator of S100A8/A9 expression, on IL-8 secretion. Methods Differentiated HL-60 cells, a human promyelocytic leukemia cell line that can be induced to differentiate into neutrophil-like cells, were used as a model of human neutrophils and treated with N- formyl-methionyl-leucyl-phenylalanine (fMLF), a bacterial peptide that activates neutrophils. shRNA knockdown was used to define the role of selected targets (S100A8/A9 and miRNA-132-5p) on IL-8 secretion. Results and discussion Different types of cytokines engage different signaling pathways in the secretion process. IL-8 release is tightly regulated by Ca2+ binding proteins S100A8/A9. miRNA-132-5p is up-regulated over time upon fMLF stimulation and decreases S100A8/A9 expression and IL-8 secretion. Conclusion These findings reveal a novel regulatory loop involving S100A8/A9 and miRNA-132-5p that modulates IL-8 secretion by neutrophils in inflammatory conditions. This loop could be a potential target for therapeutic intervention in inflammatory diseases.
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Affiliation(s)
- Yang Zhou
- Department of Life Sciences and Medicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Milène Tetsi Nomigni
- Department of Life Sciences and Medicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Anthoula Gaigneaux
- Department of Life Sciences and Medicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Fabrice Tolle
- Department of Life Sciences and Medicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Helen L. Wright
- Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Jean-Luc Bueb
- Department of Life Sciences and Medicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Sabrina Bréchard
- Department of Life Sciences and Medicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
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2
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Teder T, Haeggström JZ, Airavaara M, Lõhelaid H. Cross-talk between bioactive lipid mediators and the unfolded protein response in ischemic stroke. Prostaglandins Other Lipid Mediat 2023; 168:106760. [PMID: 37331425 DOI: 10.1016/j.prostaglandins.2023.106760] [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: 03/28/2023] [Revised: 05/27/2023] [Accepted: 06/15/2023] [Indexed: 06/20/2023]
Abstract
Ischemic cerebral stroke is a severe medical condition that affects about 15 million people every year and is the second leading cause of death and disability globally. Ischemic stroke results in neuronal cell death and neurological impairment. Current therapies may not adequately address the deleterious metabolic changes and may increase neurological damage. Oxygen and nutrient depletion along with the tissue damage result in endoplasmic reticulum (ER) stress, including the Unfolded Protein Response (UPR), and neuroinflammation in the affected area and cause cell death in the lesion core. The spatio-temporal production of lipid mediators, either pro-inflammatory or pro-resolving, decides the course and outcome of stroke. The modulation of the UPR as well as the resolution of inflammation promotes post-stroke cellular viability and neuroprotection. However, studies about the interplay between the UPR and bioactive lipid mediators remain elusive and this review gives insights about the crosstalk between lipid mediators and the UPR in ischemic stroke. Overall, the treatment of ischemic stroke is often inadequate due to lack of effective drugs, thus, this review will provide novel therapeutical strategies that could promote the functional recovery from ischemic stroke.
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Affiliation(s)
- Tarvi Teder
- Division of Physiological Chemistry II, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Jesper Z Haeggström
- Division of Physiological Chemistry II, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Mikko Airavaara
- Neuroscience Center, HiLIFE, University of Helsinki, Finland; Drug Research Program, Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy, University of Helsinki, Finland
| | - Helike Lõhelaid
- Neuroscience Center, HiLIFE, University of Helsinki, Finland; Drug Research Program, Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy, University of Helsinki, Finland.
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3
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Lind S, Wu Y, Sundqvist M, Forsman H, Dahlgren C. An increase in the cytosolic concentration of free calcium ions activates the neutrophil NADPH-oxidase provided that the free fatty acid receptor 2 has been allosterically modulated. Cell Signal 2023; 107:110687. [PMID: 37105507 DOI: 10.1016/j.cellsig.2023.110687] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 04/19/2023] [Accepted: 04/20/2023] [Indexed: 04/29/2023]
Abstract
Signals generated by free fatty acid receptor 2 (FFA2R) can activate the neutrophil NADPH-oxidase without involvement of any orthosteric FFA2R agonist. The initiating signals may be generated by P2Y2R, the receptor for ATP. An FFA2R specific allosteric modulator (PAM; Cmp58) was required for this response and used to investigate the mechanism by which signals generated by ATP/P2Y2R activate an FFA2R dependent process. The P2Y2R induced signal that together with the modulated FFA2R activates neutrophils, was generated downstream of the Gαq containing G protein coupled to P2Y2R. A rise in the cytosolic concentration of ionized calcium ([Ca2+]i) was hypothesized to be the important signal. The hypothesis gained support from the finding that the modulator transferred the neutrophils to a Ca2+sensitive state. The rise in [Ca2+]i induced by the Ca2+ specific ionophore ionomycin, activated the neutrophils provided that an allosteric modulator was bound to FFA2R. The activity of the superoxide generating NADPH-oxidase induced by ionomycin was rapidly terminated and the FFA2Rs could then no longer be activated by the FFA2R agonist propionate or by the signal generated by ATP/P2Y2R. The non-responding state of FFA2R was, however, revoked by a cross-activating allosteric FFA2R modulator. The [Ca2+]i mediated activation of neutrophils with their FFA2Rs allosterically modulated, represent a unique regulatory receptor crosstalk mechanism by which the activation potency of a G protein coupled receptor is controlled by a receptor-crosstalk signaling system operating from the cytosolic side of the plasma membrane.
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Affiliation(s)
- Simon Lind
- Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Sweden
| | - Yanling Wu
- Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Sweden
| | - Martina Sundqvist
- Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Sweden
| | - Huamei Forsman
- Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Sweden
| | - Claes Dahlgren
- Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Sweden.
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4
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Guo R, Yan Z, Liao H, Guo D, Tao R, Yu X, Zhu Z, Guo W. Ibrutinib suppresses the activation of neutrophils and macrophages and exerts therapeutic effect on acute peritonitis induced by zymosan. Int Immunopharmacol 2022; 113:109469. [DOI: 10.1016/j.intimp.2022.109469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 11/10/2022] [Accepted: 11/14/2022] [Indexed: 11/25/2022]
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5
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Kerkhofs M, Vervloessem T, Luyten T, Stopa KB, Chen J, Vangheluwe P, Bultynck G, Vervliet T. The alkalinizing, lysosomotropic agent ML-9 induces a pH-dependent depletion of ER Ca 2+ stores in cellulo. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2022; 1869:119308. [PMID: 35710019 DOI: 10.1016/j.bbamcr.2022.119308] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 04/30/2022] [Accepted: 05/30/2022] [Indexed: 06/15/2023]
Abstract
ML-9 elicits a broad spectrum of effects in cells, including inhibition of myosin light chain kinase, inhibition of store-operated Ca2+ entry and lysosomotropic actions that result in prostate cancer cell death. Moreover, the compound also affects endoplasmic reticulum (ER) Ca2+ homeostasis, although the underlying mechanisms remain unclear. We found that ML-9 provokes a rapid mobilization of Ca2+ from ER independently of IP3Rs or TMBIM6/Bax Inhibitor-1, two ER Ca2+-leak channels. Moreover, in unidirectional 45Ca2+ fluxes in permeabilized cells, ML-9 was able to reduce ER Ca2+-store content. Although the ER Ca2+ store content was decreased, ML-9 did not directly inhibit SERCA's ATPase activity in vitro using microsomal preparations. Consistent with its chemical properties as a cell-permeable weak alkalinizing agent (calculated pKa of 8.04), ML-9 provoked a rapid increase in cytosolic pH preceding the Ca2+ efflux from the ER. Pre-treatment with the weak acid 3NPA blunted the ML-9-evoked increase in intracellular pH and subsequent ML-9-induced Ca2+ mobilization from the ER. This experiment underpins a causal link between ML-9's impact on the pH and Ca2+ dynamics. Overall, our work indicates that the lysosomotropic drug ML-9 may not only impact lysosomal compartments but also have severe impacts on ER Ca2+ handling in cellulo.
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Affiliation(s)
- Martijn Kerkhofs
- KU Leuven, Laboratory of Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine, 3000 Leuven, Belgium
| | - Tamara Vervloessem
- KU Leuven, Laboratory of Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine, 3000 Leuven, Belgium
| | - Tomas Luyten
- KU Leuven, Laboratory of Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine, 3000 Leuven, Belgium
| | - Kinga B Stopa
- Jagiellonian University, Malopolska Centre of Biotechnology, 30-387 Krakow, Poland
| | - Jialin Chen
- KU Leuven, Laboratory of Cellular Transport Systems, Department of Cellular and Molecular Medicine, 3000 Leuven, Belgium
| | - Peter Vangheluwe
- KU Leuven, Laboratory of Cellular Transport Systems, Department of Cellular and Molecular Medicine, 3000 Leuven, Belgium
| | - Geert Bultynck
- KU Leuven, Laboratory of Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine, 3000 Leuven, Belgium.
| | - Tim Vervliet
- KU Leuven, Laboratory of Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine, 3000 Leuven, Belgium.
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6
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Klas K, Ondracek AS, Hofbauer TM, Mangold A, Pfisterer K, Laggner M, Copic D, Direder M, Bormann D, Ankersmit HJ, Mildner M. The Effect of Paracrine Factors Released by Irradiated Peripheral Blood Mononuclear Cells on Neutrophil Extracellular Trap Formation. Antioxidants (Basel) 2022; 11:antiox11081559. [PMID: 36009277 PMCID: PMC9405389 DOI: 10.3390/antiox11081559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 08/09/2022] [Accepted: 08/10/2022] [Indexed: 11/29/2022] Open
Abstract
Neutrophil extracellular trap (NET)-formation represents an important defence mechanism for the rapid clearance of infections. However, exaggerated NET formation has been shown to negatively affect tissue-regeneration after injury. As our previous studies revealed the strong tissue-protective and regenerative properties of the secretome of stressed peripheral blood mononuclear cells (PBMCsec), we here investigated the influence of PBMCsec on the formation of NETs. The effect of PBMCsec on NET formation was assessed ex vivo in ionomycin stimulated neutrophils derived from healthy donors using flow cytometry, image stream analysis, and quantification of released extracellular DNA. The effect of PBMCsec on molecular mechanisms involved in NET formation, including Ca-flux, protein kinase C activity, reactive oxygen species production, and protein arginine deiminase 4 activity, were analysed. Our results showed that PBMCsec significantly inhibited NET formation. Investigation of the different biological substance classes found in PBMCsec revealed only a partial reduction in NET formation, suggesting a synergistic effect. Mechanistically, PBMCsec treatment did not interfere with calcium signalling and PKC-activation, but exerted anti-oxidant activity, as evidenced by reduced levels of reactive oxygen species and upregulation of heme oxygenase 1 and hypoxia inducible-factor 1 in PBMCsec-treated neutrophils. In addition, PBMCsec strongly inhibited the activation of protein arginine deiminase 4 (PAD4), ultimately leading to the inhibition of NET formation. As therapeutics antagonizing excessive NET formation are not currently available, our study provides a promising novel treatment option for a variety of conditions resulting from exaggerated NET formation.
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Affiliation(s)
- Katharina Klas
- Laboratory for Cardiac and Thoracic Diagnosis, Regeneration and Applied Immunology, Department of Thoracic Surgery, Medical University of Vienna, 1090 Vienna, Austria
- Aposcience AG, 1200 Vienna, Austria
| | - Anna S Ondracek
- Division of Cardiology, Department of Internal Medicine II, Vienna General Hospital, Medical University of Vienna, 1090 Vienna, Austria
| | - Thomas M Hofbauer
- Division of Cardiology, Department of Internal Medicine II, Vienna General Hospital, Medical University of Vienna, 1090 Vienna, Austria
| | - Andreas Mangold
- Division of Cardiology, Department of Internal Medicine II, Vienna General Hospital, Medical University of Vienna, 1090 Vienna, Austria
| | - Karin Pfisterer
- Department of Dermatology, Medical University of Vienna, 1090 Vienna, Austria
| | - Maria Laggner
- Laboratory for Cardiac and Thoracic Diagnosis, Regeneration and Applied Immunology, Department of Thoracic Surgery, Medical University of Vienna, 1090 Vienna, Austria
- Aposcience AG, 1200 Vienna, Austria
| | - Dragan Copic
- Laboratory for Cardiac and Thoracic Diagnosis, Regeneration and Applied Immunology, Department of Thoracic Surgery, Medical University of Vienna, 1090 Vienna, Austria
- Aposcience AG, 1200 Vienna, Austria
| | - Martin Direder
- Laboratory for Cardiac and Thoracic Diagnosis, Regeneration and Applied Immunology, Department of Thoracic Surgery, Medical University of Vienna, 1090 Vienna, Austria
- Aposcience AG, 1200 Vienna, Austria
| | - Daniel Bormann
- Laboratory for Cardiac and Thoracic Diagnosis, Regeneration and Applied Immunology, Department of Thoracic Surgery, Medical University of Vienna, 1090 Vienna, Austria
- Aposcience AG, 1200 Vienna, Austria
| | - Hendrik Jan Ankersmit
- Laboratory for Cardiac and Thoracic Diagnosis, Regeneration and Applied Immunology, Department of Thoracic Surgery, Medical University of Vienna, 1090 Vienna, Austria
- Aposcience AG, 1200 Vienna, Austria
| | - Michael Mildner
- Department of Dermatology, Medical University of Vienna, 1090 Vienna, Austria
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7
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Sex-dependent effect of aging on calcium signaling and expression of TRPM2 and CRAC channels in human neutrophils. Hum Immunol 2022; 83:645-655. [PMID: 35660323 DOI: 10.1016/j.humimm.2022.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 04/26/2022] [Accepted: 05/15/2022] [Indexed: 11/22/2022]
Abstract
The vulnerability of older adults to bacterial infections has been associated with age-related changes in neutrophils. We analyzed the consequences of aging on calcium (Ca2+) mobilization and TRPM2 and CRAC channels expression in human neutrophils. The percentages of granulocytes, mature neutrophils, and neutrophil precursors were equivalent between young and older adults. However, neutrophil chemotaxis towards IL-8, C5a, or fMLP was lower in older adults of both sexes. Interestingly, a stronger Ca2+ transient followed by an identical Ca2+ influx to IL-8 was observed in older adult females. In addition, the Ca2+ response to LPS was delayed and prolonged in neutrophils of older adult males. There was no significant difference in Ca2+ response to fMLP, C5a, or store-operated Ca2+ entry in the older adults. There were also no differences in the expression of CXCR2, CD88, FPLR1, and TLR4. Interestingly, TRPM2- and ORAI1-mRNA expression was lower in neutrophils of older adults, mainly in females. Both channels were detected intracellularly in the neutrophils. TRPM2 was in late endosomes in young adults and in lysosomes in older adult neutrophils. In summary, defective neutrophil chemotaxis in aging seemed not to stem from alterations in Ca2+ signals; nevertheless, the low TRPM2 and ORAI1 expression may affect other functions.
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8
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Li W, Chen JY, Sun C, Sparks RP, Pantano L, Rahman RU, Moran SP, Pondick JV, Kirchner R, Wrobel D, Bieler M, Sauer A, Ho Sui SJ, Doerner JF, Rippmann JF, Mullen AC. Nanchangmycin regulates FYN, PTK2, and MAPK1/3 to control the fibrotic activity of human hepatic stellate cells. eLife 2022; 11:74513. [PMID: 35617485 PMCID: PMC9135407 DOI: 10.7554/elife.74513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 05/06/2022] [Indexed: 01/19/2023] Open
Abstract
Chronic liver injury causes fibrosis, characterized by the formation of scar tissue resulting from excessive accumulation of extracellular matrix (ECM) proteins. Hepatic stellate cell (HSC) myofibroblasts are the primary cell type responsible for liver fibrosis, yet there are currently no therapies directed at inhibiting the activity of HSC myofibroblasts. To search for potential anti-fibrotic compounds, we performed a high-throughput compound screen in primary human HSC myofibroblasts and identified 19 small molecules that induce HSC inactivation, including the polyether ionophore nanchangmycin (NCMC). NCMC induces lipid re-accumulation while reducing collagen expression, deposition of collagen in the extracellular matrix, cell proliferation, and migration. We find that NCMC increases cytosolic Ca2+ and reduces the phosphorylated protein levels of FYN, PTK2 (FAK), MAPK1/3 (ERK2/1), HSPB1 (HSP27), and STAT5B. Further, depletion of each of these kinases suppress COL1A1 expression. These studies reveal a signaling network triggered by NCMC to inactivate HSC myofibroblasts and reduce expression of proteins that compose the fibrotic scar. Identification of the antifibrotic effects of NCMC and the elucidation of pathways by which NCMC inhibits fibrosis provide new tools and therapeutic targets that could potentially be utilized to combat the development and progression of liver fibrosis.
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Affiliation(s)
- Wenyang Li
- Division of Gastroenterology, Massachusetts General HospitalBostonUnited States,Harvard Medical SchoolBostonUnited States
| | - Jennifer Y Chen
- Division of Gastroenterology, Massachusetts General HospitalBostonUnited States,Harvard Medical SchoolBostonUnited States
| | - Cheng Sun
- Division of Gastroenterology, Massachusetts General HospitalBostonUnited States,Harvard Medical SchoolBostonUnited States
| | - Robert P Sparks
- Division of Gastroenterology, Massachusetts General HospitalBostonUnited States,Harvard Medical SchoolBostonUnited States
| | - Lorena Pantano
- Harvard T.H. Chan School of Public HealthBostonUnited States
| | - Raza-Ur Rahman
- Division of Gastroenterology, Massachusetts General HospitalBostonUnited States,Harvard Medical SchoolBostonUnited States
| | - Sean P Moran
- Division of Gastroenterology, Massachusetts General HospitalBostonUnited States,Harvard Medical SchoolBostonUnited States
| | - Joshua V Pondick
- Division of Gastroenterology, Massachusetts General HospitalBostonUnited States,Harvard Medical SchoolBostonUnited States
| | - Rory Kirchner
- Harvard T.H. Chan School of Public HealthBostonUnited States
| | | | | | - Achim Sauer
- Boehringer Ingelheim Pharma GmbH & CoBiberachGermany
| | | | | | | | - Alan C Mullen
- Division of Gastroenterology, Massachusetts General HospitalBostonUnited States,Harvard Medical SchoolBostonUnited States,Harvard Stem Cell InstituteCambridgeUnited States
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9
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A Novel Microfluidic Device for the Neutrophil Functional Phenotype Analysis: Effects of Glucose and Its Derivatives AGEs. MICROMACHINES 2021; 12:mi12080944. [PMID: 34442566 PMCID: PMC8399494 DOI: 10.3390/mi12080944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 08/06/2021] [Accepted: 08/07/2021] [Indexed: 11/17/2022]
Abstract
Neutrophil dysfunction is closely related to the pathophysiology of patients with diabetes mellitus, but existing immunoassays are difficult to implement in clinical applications, and neutrophil’s chemotaxis as a functional biomarker for diabetes mellitus prognostic remains largely unexplored. Herein, a novel microfluidic device consisted of four independent test units with four cell docking structures was developed to study the neutrophil chemotaxis, which allowed multiple cell migration observations under a single field of view (FOV) and guaranteed more reliable results. In vitro studies, the chemotaxis of healthy neutrophils to N-Formyl-Met-Leu-Phe (fMLP) gradient (0, 10, 100, and 1000 nM) was concentration-dependent. The distinct promotion or suppression in the chemotaxis of metformin or pravastatin pretreated cells were observed after exposure to 100 nM fMLP gradient, indicating the feasibility and efficiency of this novel microfluidic device for clinically relevant evaluation of neutrophil functional phenotype. Further, the chemotaxis of neutrophils pretreated with 25, 50, or 70 mM of glucose was quantitatively lower than that of the control groups (i.e., 5 mM normal serum level). Neutrophils exposed to highly concentrated advanced glycation end products (AGEs) (0.2, 0.5, or 1.0 μM; 0.13 μM normal serum AGEs level), a product of prolonged hyperglycemia, showed that the higher the AGEs concentration was, the weaker the migration speed became. Specifically, neutrophils exposed to high concentrations of glucose or AGEs also showed a stronger drifting along with the flow, further demonstrating the change of neutrophil chemotaxis. Interestingly, adding the N-benzyl-4-chloro-N-cyclohexylbenzamide (FPS-ZM1) (i.e., high-affinity RAGE inhibitor) into the migration medium with AGEs could hinder the binding between AGEs and AGE receptor (RAGE) located on the neutrophil, thereby keeping the normal chemotaxis of neutrophils than the ones incubated with AGEs alone. These results revealed the negative effects of high concentrations of glucose and AGEs on the neutrophil chemotaxis, suggesting that patients with diabetes should manage serum AGEs and also pay attention to blood glucose indexes. Overall, this novel microfluidic device could significantly characterize the chemotaxis of neutrophils and have the potential to be further improved into a tool for risk stratification of diabetes mellitus.
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10
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Role of protons in calcium signaling. Biochem J 2021; 478:895-910. [PMID: 33635336 DOI: 10.1042/bcj20200971] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 01/28/2021] [Accepted: 02/01/2021] [Indexed: 02/03/2023]
Abstract
Thirty-six years after the publication of the important article by Busa and Nuccitelli on the variability of intracellular pH (pHi) and the interdependence of pHi and intracellular Ca2+ concentration ([Ca2+]i), little research has been carried out on pHi and calcium signaling. Moreover, the results appear to be contradictory. Some authors claim that the increase in [Ca2+]i is due to a reduction in pHi, others that it is caused by an increase in pHi. The reasons for these conflicting results have not yet been discussed and clarified in an exhaustive manner. The idea that variations in pHi are insignificant, because cellular buffers quickly stabilize the pHi, may be a limiting and fundamentally wrong concept. In fact, it has been shown that protons can move and react in the cell before they are neutralized. Variations in pHi have a remarkable impact on [Ca2+]i and hence on some of the basic biochemical mechanisms of calcium signaling. This paper focuses on the possible triggering role of protons during their short cellular cycle and it suggests a new hypothesis for an IP3 proton dependent mechanism of action.
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11
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Najder K, Rugi M, Lebel M, Schröder J, Oster L, Schimmelpfennig S, Sargin S, Pethő Z, Bulk E, Schwab A. Role of the Intracellular Sodium Homeostasis in Chemotaxis of Activated Murine Neutrophils. Front Immunol 2020; 11:2124. [PMID: 33013896 PMCID: PMC7506047 DOI: 10.3389/fimmu.2020.02124] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 08/05/2020] [Indexed: 12/17/2022] Open
Abstract
The importance of the intracellular Ca2+ concentration ([Ca2+]i) in neutrophil function has been intensely studied. However, the role of the intracellular Na+ concentration ([Na+]i) which is closely linked to the intracellular Ca2+ regulation has been largely overlooked. The [Na+]i is regulated by Na+ transport proteins such as the Na+/Ca2+-exchanger (NCX1), Na+/K+-ATPase, and Na+-permeable, transient receptor potential melastatin 2 (TRPM2) channel. Stimulating with either N-formylmethionine-leucyl-phenylalanine (fMLF) or complement protein C5a causes distinct changes of the [Na+]i. fMLF induces a sustained increase of [Na+]i, surprisingly, reaching higher values in TRPM2-/- neutrophils. This outcome is unexpected and remains unexplained. In both genotypes, C5a elicits only a transient rise of the [Na+]i. The difference in [Na+]i measured at t = 10 min after stimulation is inversely related to neutrophil chemotaxis. Neutrophil chemotaxis is more efficient in C5a than in an fMLF gradient. Moreover, lowering the extracellular Na+ concentration from 140 to 72 mM improves chemotaxis of WT but not of TRPM2-/- neutrophils. Increasing the [Na+]i by inhibiting the Na+/K+-ATPase results in disrupted chemotaxis. This is most likely due to the impact of the altered Na+ homeostasis and presumably NCX1 function whose expression was shown by means of qPCR and which critically relies on proper extra- to intracellular Na+ concentration gradients. Increasing the [Na+]i by a few mmol/l may suffice to switch its transport mode from forward (Ca2+-efflux) to reverse (Ca2+-influx) mode. The role of NCX1 in neutrophil chemotaxis is corroborated by its blocker, which also causes a complete inhibition of chemotaxis.
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Affiliation(s)
- Karolina Najder
- Institute of Physiology II, University Hospital Münster, Münster, Germany
| | - Micol Rugi
- Institute of Physiology II, University Hospital Münster, Münster, Germany
- University of Florence, Florence, Italy
| | - Mégane Lebel
- University of Sherbrooke, Sherbrooke, QC, Canada
| | - Julia Schröder
- Institute of Physiology II, University Hospital Münster, Münster, Germany
| | - Leonie Oster
- Institute of Physiology II, University Hospital Münster, Münster, Germany
| | | | - Sarah Sargin
- Institute of Physiology II, University Hospital Münster, Münster, Germany
| | - Zoltán Pethő
- Institute of Physiology II, University Hospital Münster, Münster, Germany
| | - Etmar Bulk
- Institute of Physiology II, University Hospital Münster, Münster, Germany
| | - Albrecht Schwab
- Institute of Physiology II, University Hospital Münster, Münster, Germany
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