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Dreher L, Bode M, Ehnert N, Meyer-Schwesinger C, Wiech T, Köhl J, Huber TB, Freiwald T, Herrnstadt GR, Wenzel UO. Role of the Anaphylatoxin Receptor C5aR2 in Angiotensin II-Induced Hypertension and Hypertensive End-Organ Damage. Am J Hypertens 2024; 37:810-825. [PMID: 38934290 DOI: 10.1093/ajh/hpae082] [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: 02/28/2024] [Revised: 05/17/2024] [Accepted: 06/20/2024] [Indexed: 06/28/2024] Open
Abstract
BACKROUND Complement activation may facilitate hypertension through its effects on immune responses. The anaphylatoxin C5a, a major inflammatory effector, binds to the C5a receptors 1 and 2 (C5aR1, C5aR2). We have recently shown that C5aR1-/- mice have reduced hypertensive renal injury. The role of C5aR2 in hypertension is unknown. METHODS For examination of C5aR2 expression on infiltrating and resident renal cells a tandem dye Tomato-C5aR2 knock-in reporter mouse was used. Human C5aR2 expression was analyzed in a single-cell RNAseq data set from the kidneys of hypertensive patients. Finally, we examined the effect of angiotensin II-induced hypertension in C5aR2-deficient mice. RESULTS Flow cytometric analysis of leukocytes isolated from kidneys of the reporter mice showed that dendritic cells are the major C5aR2-expressing population (34%) followed by monocyte/macrophages (30%) and neutrophils (14%). Using confocal microscopy C5aR2 was not detected in resident renal or cardiac cells. In the human kidney, C5aR2 was also mainly found in monocytes, macrophages, and dendritic cells with a significantly higher expression in hypertension (P < 0.05). Unilateral nephrectomy was performed followed by infusion of Ang II (0.75 ng/g/min) and a high salt diet in wildtype (n = 18) and C5aR2-deficient mice (n = 14). Blood pressure, renal injury (albuminuria, glomerular filtration rate, glomerular and tubulointerstitial injury, inflammation), and cardiac injury (cardiac fibrosis, heart weight, gene expression) did not differ between hypertensive wildtype and C5aR2-/- mice. CONCLUSIONS In summary, C5aR2 is mainly expressed in myeloid cells in the kidney in mice and humans but its deficiency has no effect on Ang II-induced hypertensive injury.
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Affiliation(s)
- Leonie Dreher
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Marlies Bode
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Nicolas Ehnert
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Catherine Meyer-Schwesinger
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Department of Cellular and Integrative Physiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Thorsten Wiech
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Department of Pathology, Section of Nephropathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Jörg Köhl
- Institute for Systemic Inflammation Research, Lübeck., Germany
| | - Tobias B Huber
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Tilo Freiwald
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Georg R Herrnstadt
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Ulrich O Wenzel
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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Fernandes DC, Tambourgi DV. Complement System Inhibitory Drugs in a Zebrafish ( Danio rerio) Model: Computational Modeling. Int J Mol Sci 2023; 24:13895. [PMID: 37762197 PMCID: PMC10530807 DOI: 10.3390/ijms241813895] [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: 08/08/2023] [Revised: 09/04/2023] [Accepted: 09/05/2023] [Indexed: 09/29/2023] Open
Abstract
The dysregulation of complement system activation usually results in acute or chronic inflammation and can contribute to the development of various diseases. Although the activation of complement pathways is essential for innate defense, exacerbated activity of this system may be harmful to the host. Thus, drugs with the potential to inhibit the activation of the complement system may be important tools in therapy for diseases associated with complement system activation. The synthetic peptides Cp40 and PMX205 can be highlighted in this regard, given that they selectively inhibit the C3 and block the C5a receptor (C5aR1), respectively. The zebrafish (Danio rerio) is a robust model for studying the complement system. The aim of the present study was to use in silico computational modeling to investigate the hypothesis that these complement system inhibitor peptides interact with their target molecules in zebrafish, for subsequent in vivo validation. For this, we analyzed molecular docking interactions between peptides and target molecules. Our study demonstrated that Cp40 and the cyclic peptide PMX205 have positive interactions with their respective zebrafish targets, thus suggesting that zebrafish can be used as an animal model for therapeutic studies on these inhibitors.
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Affiliation(s)
| | - Denise V. Tambourgi
- Immunochemistry Laboratory, Butantan Institute, São Paulo 05503-900, Brazil;
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Bode M, Diemer JN, Luu TV, Ehnert N, Teigeler T, Wiech T, Lindenmeyer MT, Herrnstadt GR, Bülow J, Huber TB, Tomas NM, Wenzel UO. Complement component C3 as a new target to lower albuminuria in hypertensive kidney disease. Br J Pharmacol 2023; 180:2412-2435. [PMID: 37076314 DOI: 10.1111/bph.16097] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 04/08/2023] [Accepted: 04/12/2023] [Indexed: 04/21/2023] Open
Abstract
BACKGROUND AND PURPOSE Complement activation may drive hypertension through its effects on immunity and tissue integrity. EXPERIMENTAL APPROACH We examined expression of C3, the central protein of the complement cascade, in hypertension. KEY RESULTS Increased C3 expression was found in kidney biopsies and micro-dissected glomeruli of patients with hypertensive nephropathy. Renal single cell RNA sequence data from normotensive and hypertensive patients confirmed expression of C3 in different cellular compartments of the kidney. In angiotensin II (Ang II) induced hypertension renal C3 expression was up-regulated. C3-/- mice revealed a significant lower albuminuria in the early phase of hypertension. However, no difference was found for blood pressure, renal injury (histology, glomerular filtration rate, inflammation) and cardiac injury (fibrosis, weight, gene expression) between C3-/- and wildtype mice after Ang II infusion. Also, in deoxycorticosterone acetate (DOCA) salt hypertension, a significantly lower albuminuria was found in the first weeks of hypertension in C3 deficient mice but no significant difference in renal and cardiac injury. Down-regulation of C3 by C3 targeting GalNAc (n-acetylgalactosamine) small interfering RNA (siRNA) conjugate decreased C3 in the liver by 96% and lowered albuminuria in the early phase but showed no effect on blood pressure and end-organ damage. Inhibition of complement C5 by siRNA showed no effect on albuminuria. CONCLUSION AND IMPLICATIONS Increased C3 expression is found in the kidneys of hypertensive mice and men. Genetic and therapeutic knockdown of C3 improved albuminuria in the early phase of hypertension but did not ameliorate arterial blood pressure nor renal and cardiac injury.
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Affiliation(s)
- Marlies Bode
- III. Department of Medicine, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - Jan Niklas Diemer
- III. Department of Medicine, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - The Vinh Luu
- III. Department of Medicine, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - Nikolas Ehnert
- III. Department of Medicine, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - Teresa Teigeler
- III. Department of Medicine, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - Thorsten Wiech
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Institute for Pathology, Section Nephropathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Maja T Lindenmeyer
- III. Department of Medicine, University Hospital Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Georg R Herrnstadt
- III. Department of Medicine, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - Jasmin Bülow
- Institute of Orthopedic Research and Biomechanics, University Medical Center Ulm, Ulm, Germany
| | - Tobias B Huber
- III. Department of Medicine, University Hospital Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Nicola M Tomas
- III. Department of Medicine, University Hospital Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Ulrich O Wenzel
- III. Department of Medicine, University Hospital Hamburg-Eppendorf, Hamburg, Germany
- Hamburg Center for Kidney Health (HCKH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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Schanzenbacher J, Köhl J, Karsten CM. Anaphylatoxins spark the flame in early autoimmunity. Front Immunol 2022; 13:958392. [PMID: 35958588 PMCID: PMC9358992 DOI: 10.3389/fimmu.2022.958392] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 06/29/2022] [Indexed: 11/13/2022] Open
Abstract
The complement system (CS) is an ancient and highly conserved part of the innate immune system with important functions in immune defense. The multiple fragments bind to specific receptors on innate and adaptive immune cells, the activation of which translates the initial humoral innate immune response (IR) into cellular innate and adaptive immunity. Dysregulation of the CS has been associated with the development of several autoimmune disorders such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), ANCA-associated vasculitis, and autoimmune bullous dermatoses (AIBDs), where complement drives the inflammatory response in the effector phase. The role of the CS in autoimmunity is complex. On the one hand, complement deficiencies were identified as risk factors to develop autoimmune disorders. On the other hand, activation of complement can drive autoimmune responses. The anaphylatoxins C3a and C5a are potent mediators and regulators of inflammation during the effector phase of autoimmunity through engagement of specific anaphylatoxin receptors, i.e., C3aR, C5aR1, and C5aR2 either on or in immune cells. In addition to their role in innate IRs, anaphylatoxins regulate humoral and cellular adaptive IRs including B-cell and T-cell activation, differentiation, and survival. They regulate B- and T-lymphocyte responses either directly or indirectly through the activation of anaphylatoxin receptors via dendritic cells that modulate lymphocyte function. Here, we will briefly review our current understanding of the complex roles of anaphylatoxins in the regulation of immunologic tolerance and the early events driving autoimmunity and the implications of such regulation for therapeutic approaches that target the CS.
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Affiliation(s)
- Jovan Schanzenbacher
- Institute for Systemic Inflammation Research, University of Lübeck, Lübeck, Germany
| | - Jörg Köhl
- Institute for Systemic Inflammation Research, University of Lübeck, Lübeck, Germany
- Division of Immunobiology, Cincinnati Childrens Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH, United States
| | - Christian M. Karsten
- Institute for Systemic Inflammation Research, University of Lübeck, Lübeck, Germany
- *Correspondence: Christian M. Karsten,
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