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Burmeister A, Vidal-y-Sy S, Liu X, Mess C, Wang Y, Konwar S, Tschongov T, Häffner K, Huck V, Schneider SW, Gorzelanny C. Impact of neutrophil extracellular traps on fluid properties, blood flow and complement activation. Front Immunol 2022; 13:1078891. [PMID: 36591269 PMCID: PMC9800590 DOI: 10.3389/fimmu.2022.1078891] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Accepted: 12/01/2022] [Indexed: 12/23/2022] Open
Abstract
Introduction The intravascular formation of neutrophil extracellular traps (NETs) is a trigger for coagulation and blood vessel occlusion. NETs are released from neutrophils as a response to strong inflammatory signals in the course of different diseases such as COVID-19, cancer or antiphospholipid syndrome. NETs are composed of large, chromosomal DNA fibers decorated with a variety of proteins such as histones. Previous research suggested a close mechanistic crosstalk between NETs and the coagulation system involving the coagulation factor XII (FXII), von Willebrand factor (VWF) and tissue factor. However, the direct impact of NET-related DNA fibers on blood flow and blood aggregation independent of the coagulation cascade has remained elusive. Methods In the present study, we used different microfluidic setups in combination with fluorescence microscopy to investigate the influence of neutrophil-derived extracellular DNA fibers on blood rheology, intravascular occlusion and activation of the complement system. Results We found that extended DNA fiber networks decelerate blood flow and promote intravascular occlusion of blood vessels independent of the plasmatic coagulation. Associated with the DNA dependent occlusion of the flow channel was the strong activation of the complement system characterized by the production of complement component 5a (C5a). Vice versa, we detected that the local activation of the complement system at the vascular wall was a trigger for NET release. Discussion In conclusion, we found that DNA fibers as the principal component of NETs are sufficient to induce blood aggregation even in the absence of the coagulation system. Moreover, we discovered that complement activation at the endothelial surface promoted NET formation. Our data envisions DNA degradation and complement inhibition as potential therapeutic strategies in NET-induced coagulopathies.
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Affiliation(s)
- Antonia Burmeister
- Department of Dermatology and Venereology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Sabine Vidal-y-Sy
- Department of Dermatology and Venereology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Xiaobo Liu
- Department of Dermatology and Venereology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Christian Mess
- Department of Dermatology and Venereology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Yuanyuan Wang
- Department of Dermatology and Venereology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Swagata Konwar
- Department of Internal Medicine IV, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Todor Tschongov
- Department of Internal Medicine IV, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Karsten Häffner
- Department of Internal Medicine IV, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Volker Huck
- Department of Dermatology and Venereology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Stefan W. Schneider
- Department of Dermatology and Venereology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany,*Correspondence: Christian Gorzelanny, ; Stefan W. Schneider,
| | - Christian Gorzelanny
- Department of Dermatology and Venereology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany,*Correspondence: Christian Gorzelanny, ; Stefan W. Schneider,
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Götz P, Azubuike-Osu SO, Braumandl A, Arnholdt C, Kübler M, Richter L, Lasch M, Bobrowski L, Preissner KT, Deindl E. Cobra Venom Factor Boosts Arteriogenesis in Mice. Int J Mol Sci 2022; 23:ijms23158454. [PMID: 35955584 PMCID: PMC9368946 DOI: 10.3390/ijms23158454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 07/25/2022] [Accepted: 07/27/2022] [Indexed: 01/27/2023] Open
Abstract
Arteriogenesis, the growth of natural bypass blood vessels, can compensate for the loss of arteries caused by vascular occlusive diseases. Accordingly, it is a major goal to identify the drugs promoting this innate immune system-driven process in patients aiming to save their tissues and life. Here, we studied the impact of the Cobra venom factor (CVF), which is a C3-like complement-activating protein that induces depletion of the complement in the circulation in a murine hind limb model of arteriogenesis. Arteriogenesis was induced in C57BL/6J mice by femoral artery ligation (FAL). The administration of a single dose of CVF (12.5 µg) 24 h prior to FAL significantly enhanced the perfusion recovery 7 days after FAL, as shown by Laser Doppler imaging. Immunofluorescence analyses demonstrated an elevated number of proliferating (BrdU+) vascular cells, along with an increased luminal diameter of the grown collateral vessels. Flow cytometric analyses of the blood samples isolated 3 h after FAL revealed an elevated number of neutrophils and platelet-neutrophil aggregates. Giemsa stains displayed augmented mast cell recruitment and activation in the perivascular space of the growing collaterals 8 h after FAL. Seven days after FAL, we found more CD68+/MRC-1+ M2-like polarized pro-arteriogenic macrophages around growing collaterals. These data indicate that a single dose of CVF boosts arteriogenesis by catalyzing the innate immune reactions, relevant for collateral vessel growth.
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Affiliation(s)
- Philipp Götz
- Walter-Brendel-Centre of Experimental Medicine, University Hospital, Ludwig-Maximilians-Universität München, 81377 Munich, Germany; (P.G.); or (S.O.A.-O.); (A.B.); (C.A.); (M.K.); (M.L.); (L.B.)
- Biomedical Center, Institute of Cardiovascular Physiology and Pathophysiology, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany
| | - Sharon O. Azubuike-Osu
- Walter-Brendel-Centre of Experimental Medicine, University Hospital, Ludwig-Maximilians-Universität München, 81377 Munich, Germany; (P.G.); or (S.O.A.-O.); (A.B.); (C.A.); (M.K.); (M.L.); (L.B.)
- Biomedical Center, Institute of Cardiovascular Physiology and Pathophysiology, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany
- Department of Physiology, Faculty of Basic Medical Sciences, College of Medicine, Alex Ekwueme Federal University Ndufu Alike, Abakaliki 482131, Ebonyi, Nigeria
| | - Anna Braumandl
- Walter-Brendel-Centre of Experimental Medicine, University Hospital, Ludwig-Maximilians-Universität München, 81377 Munich, Germany; (P.G.); or (S.O.A.-O.); (A.B.); (C.A.); (M.K.); (M.L.); (L.B.)
- Biomedical Center, Institute of Cardiovascular Physiology and Pathophysiology, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany
| | - Christoph Arnholdt
- Walter-Brendel-Centre of Experimental Medicine, University Hospital, Ludwig-Maximilians-Universität München, 81377 Munich, Germany; (P.G.); or (S.O.A.-O.); (A.B.); (C.A.); (M.K.); (M.L.); (L.B.)
- Biomedical Center, Institute of Cardiovascular Physiology and Pathophysiology, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany
| | - Matthias Kübler
- Walter-Brendel-Centre of Experimental Medicine, University Hospital, Ludwig-Maximilians-Universität München, 81377 Munich, Germany; (P.G.); or (S.O.A.-O.); (A.B.); (C.A.); (M.K.); (M.L.); (L.B.)
- Biomedical Center, Institute of Cardiovascular Physiology and Pathophysiology, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany
| | - Lisa Richter
- Flow Cytometry Core Facility, Biomedical Center, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany;
| | - Manuel Lasch
- Walter-Brendel-Centre of Experimental Medicine, University Hospital, Ludwig-Maximilians-Universität München, 81377 Munich, Germany; (P.G.); or (S.O.A.-O.); (A.B.); (C.A.); (M.K.); (M.L.); (L.B.)
- Biomedical Center, Institute of Cardiovascular Physiology and Pathophysiology, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany
- Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Lisa Bobrowski
- Walter-Brendel-Centre of Experimental Medicine, University Hospital, Ludwig-Maximilians-Universität München, 81377 Munich, Germany; (P.G.); or (S.O.A.-O.); (A.B.); (C.A.); (M.K.); (M.L.); (L.B.)
- Biomedical Center, Institute of Cardiovascular Physiology and Pathophysiology, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany
| | - Klaus T. Preissner
- Department of Cardiology, Kerckhoff-Heart Research Institute, Faculty of Medicine, Justus Liebig University, 35392 Giessen, Germany;
| | - Elisabeth Deindl
- Walter-Brendel-Centre of Experimental Medicine, University Hospital, Ludwig-Maximilians-Universität München, 81377 Munich, Germany; (P.G.); or (S.O.A.-O.); (A.B.); (C.A.); (M.K.); (M.L.); (L.B.)
- Biomedical Center, Institute of Cardiovascular Physiology and Pathophysiology, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany
- Correspondence: ; Tel.: +49-(0)-89-2180-76504
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Chaigneau E, Charpak S. Measurement of Blood Velocity With Laser Scanning Microscopy: Modeling and Comparison of Line-Scan Image-Processing Algorithms. Front Physiol 2022; 13:848002. [PMID: 35464098 PMCID: PMC9022085 DOI: 10.3389/fphys.2022.848002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Accepted: 02/22/2022] [Indexed: 11/13/2022] Open
Abstract
Laser scanning microscopy is widely used to measure blood hemodynamics with line-scans in physiological and pathological vessels. With scans of broken lines, i.e., lines made of several segments with different orientations, it also allows simultaneous monitoring of vessel diameter dynamics or the activity of specific cells. Analysis of red blood cell (RBC) velocity from line-scans requires specific image-processing algorithms, as angle measurements, Line-Scanning Particle Image Velocimetry (LSPIV) or Fourier transformation of line-scan images. The conditions under which these image-processing algorithms give accurate measurements have not been fully characterized although the accuracy of measurements vary according to specific experimental parameters: the vessel type, the RBC velocity, the scanning parameters, and the image signal to noise ratio. Here, we developed mathematical models for the three previously mentioned line-scan image-processing algorithms. Our models predict the experimental conditions in which RBC velocity measurements are accurate. We illustrate the case of different vessel types and give the parameter space available for each of them. Last, we developed a software generating artificial line-scan images and used it to validate our models.
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Affiliation(s)
- Emmanuelle Chaigneau
- Institut de la Vision, INSERM U968, Paris, France
- Institut de la Vision, CNRS UMR 7210, Paris, France
- Institut de la Vision, Sorbonne Université, Paris, France
- *Correspondence: Emmanuelle Chaigneau,
| | - Serge Charpak
- Institut de la Vision, INSERM U968, Paris, France
- Institut de la Vision, CNRS UMR 7210, Paris, France
- Institut de la Vision, Sorbonne Université, Paris, France
- Serge Charpak,
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4
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Lasch M, Kumaraswami K, Nasiscionyte S, Kircher S, van den Heuvel D, Meister S, Ishikawa-Ankerhold H, Deindl E. RNase A Treatment Interferes With Leukocyte Recruitment, Neutrophil Extracellular Trap Formation, and Angiogenesis in Ischemic Muscle Tissue. Front Physiol 2020; 11:576736. [PMID: 33240100 PMCID: PMC7677187 DOI: 10.3389/fphys.2020.576736] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 10/16/2020] [Indexed: 01/13/2023] Open
Abstract
Background: RNase A (the bovine equivalent to human RNase 1) and RNase 5 (angiogenin) are two closely related ribonucleases. RNase 5 is described as a powerful angiogenic factor. Whether RNase A shares the same angiogenic characteristic, or interferes with vessel growth as demonstrated for arteriogenesis, has never been investigated and is the topic of this present study. Methods and Results: To investigate whether RNase A shows a pro‐ or anti-angiogenic effect, we employed a murine hindlimb model, in which femoral artery ligation (FAL) results in arteriogenesis in the upper leg, and, due to provoked ischemia, in angiogenesis in the lower leg. C57BL/6J male mice underwent unilateral FAL, whereas the contralateral leg was sham operated. Two and seven days after the surgery and intravenous injection of RNase A (50 μg/kg dissolved in saline) or saline (control), the gastrocnemius muscles of mice were isolated from the lower legs for (immuno-) histological analyses. Hematoxylin and Eosin staining evidenced that RNase A treatment resulted in a higher degree of ischemic tissue damage. This was, however, associated with reduced angiogenesis, as evidenced by a reduced capillary/muscle fiber ratio. Moreover, RNase A treatment was associated with a significant reduction in leukocyte infiltration as shown by CD45+ (pan-leukocyte marker), Ly6G+ or MPO+ (neutrophils), MPO+/CitH3+ [neutrophil extracellular traps (NETs)], and CD68+ (macrophages) staining. CD68/MRC1 double staining revealed that RNase A treated mice showed a reduced percentage of M1-like polarized (CD68+/MRC1−) macrophages whereas the percentage of M2-like polarized (CD68+/MRC1+) macrophages was increased. Conclusion: In contrast to RNase 5, RNase A interferes with angiogenesis, which is linked to reduced leukocyte infiltration and NET formation.
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Affiliation(s)
- Manuel Lasch
- Walter-Brendel-Centre of Experimental Medicine, University Hospital, Ludwig-Maximilians-Universität München, Munich, Germany.,Biomedical Center, Institute of Cardiovascular Physiology and Pathophysiology, Ludwig-Maximilians-Universität München, Munich, Germany.,Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Konda Kumaraswami
- Walter-Brendel-Centre of Experimental Medicine, University Hospital, Ludwig-Maximilians-Universität München, Munich, Germany.,Biomedical Center, Institute of Cardiovascular Physiology and Pathophysiology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Simona Nasiscionyte
- Walter-Brendel-Centre of Experimental Medicine, University Hospital, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Susanna Kircher
- Walter-Brendel-Centre of Experimental Medicine, University Hospital, Ludwig-Maximilians-Universität München, Munich, Germany.,Biomedical Center, Institute of Cardiovascular Physiology and Pathophysiology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Dominic van den Heuvel
- Walter-Brendel-Centre of Experimental Medicine, University Hospital, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Sarah Meister
- Department of Obstetrics and Gynaecology, University Hospital, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Hellen Ishikawa-Ankerhold
- Walter-Brendel-Centre of Experimental Medicine, University Hospital, Ludwig-Maximilians-Universität München, Munich, Germany.,Department of Internal Medicine I, Faculty of Medicine, University Hospital, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Elisabeth Deindl
- Walter-Brendel-Centre of Experimental Medicine, University Hospital, Ludwig-Maximilians-Universität München, Munich, Germany.,Biomedical Center, Institute of Cardiovascular Physiology and Pathophysiology, Ludwig-Maximilians-Universität München, Munich, Germany
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5
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Kumaraswami K, Salei N, Beck S, Rambichler S, Kluever AK, Lasch M, Richter L, Schraml BU, Deindl E. A Simple and Effective Flow Cytometry-Based Method for Identification and Quantification of Tissue Infiltrated Leukocyte Subpopulations in a Mouse Model of Peripheral Arterial Disease. Int J Mol Sci 2020; 21:ijms21103593. [PMID: 32438752 PMCID: PMC7279164 DOI: 10.3390/ijms21103593] [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: 05/06/2020] [Accepted: 05/16/2020] [Indexed: 01/25/2023] Open
Abstract
Arteriogenesis, the growth of a natural bypass from pre-existing arteriolar collaterals, is an endogenous mechanism to compensate for the loss of an artery. Mechanistically, this process relies on a locally and temporally restricted perivascular infiltration of leukocyte subpopulations, which mediate arteriogenesis by supplying growth factors and cytokines. Currently, the state-of-the-art method to identify and quantify these leukocyte subpopulations in mouse models is immunohistology. However, this is a time consuming procedure. Here, we aimed to develop an optimized protocol to identify and quantify leukocyte subpopulations by means of flow cytometry in adductor muscles containing growing collateral arteries. For that purpose, adductor muscles of murine hindlimbs were isolated at day one and three after induction of arteriogenesis, enzymatically digested, and infiltrated leukocyte subpopulations were identified and quantified by flow cytometry, as exemplary shown for neutrophils and macrophages (defined as CD45+/CD11b+/Ly6G+ and CD45+/CD11b+/F4/80+ cells, respectively). In summary, we show that flow cytometry is a suitable method to identify and quantify leukocyte subpopulations in muscle tissue, and provide a detailed protocol. Flow cytometry constitutes a timesaving tool compared to histology, which might be used in addition for precise localization of leukocytes in tissue samples.
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Affiliation(s)
- Konda Kumaraswami
- Walter-Brendel-Centre of Experimental Medicine, University Hospital, LMU Munich, 81377 Munich, Germany; (K.K.); (N.S.); (S.B.); (S.R.); (A.-K.K.); (M.L.); (B.U.S.)
- Biomedical Center, Institute of Cardiovascular Physiology and Pathophysiology, LMU Munich, 82152 Planegg-Martinsried, Germany
| | - Natallia Salei
- Walter-Brendel-Centre of Experimental Medicine, University Hospital, LMU Munich, 81377 Munich, Germany; (K.K.); (N.S.); (S.B.); (S.R.); (A.-K.K.); (M.L.); (B.U.S.)
- Biomedical Center, Institute of Cardiovascular Physiology and Pathophysiology, LMU Munich, 82152 Planegg-Martinsried, Germany
| | - Sebastian Beck
- Walter-Brendel-Centre of Experimental Medicine, University Hospital, LMU Munich, 81377 Munich, Germany; (K.K.); (N.S.); (S.B.); (S.R.); (A.-K.K.); (M.L.); (B.U.S.)
- Biomedical Center, Institute of Cardiovascular Physiology and Pathophysiology, LMU Munich, 82152 Planegg-Martinsried, Germany
| | - Stephan Rambichler
- Walter-Brendel-Centre of Experimental Medicine, University Hospital, LMU Munich, 81377 Munich, Germany; (K.K.); (N.S.); (S.B.); (S.R.); (A.-K.K.); (M.L.); (B.U.S.)
- Biomedical Center, Institute of Cardiovascular Physiology and Pathophysiology, LMU Munich, 82152 Planegg-Martinsried, Germany
| | - Anna-Kristina Kluever
- Walter-Brendel-Centre of Experimental Medicine, University Hospital, LMU Munich, 81377 Munich, Germany; (K.K.); (N.S.); (S.B.); (S.R.); (A.-K.K.); (M.L.); (B.U.S.)
- Biomedical Center, Institute of Cardiovascular Physiology and Pathophysiology, LMU Munich, 82152 Planegg-Martinsried, Germany
| | - Manuel Lasch
- Walter-Brendel-Centre of Experimental Medicine, University Hospital, LMU Munich, 81377 Munich, Germany; (K.K.); (N.S.); (S.B.); (S.R.); (A.-K.K.); (M.L.); (B.U.S.)
- Biomedical Center, Institute of Cardiovascular Physiology and Pathophysiology, LMU Munich, 82152 Planegg-Martinsried, Germany
- Department of Otorhinolaryngology, Head & Neck Surgery, University Hospital, LMU Munich, 81377 Munich, Germany
| | - Lisa Richter
- Core Facility Flow Cytometry, Biomedical Centre, LMU Munich, 82152 Planegg-Martinsried, Germany;
| | - Barbara U. Schraml
- Walter-Brendel-Centre of Experimental Medicine, University Hospital, LMU Munich, 81377 Munich, Germany; (K.K.); (N.S.); (S.B.); (S.R.); (A.-K.K.); (M.L.); (B.U.S.)
- Biomedical Center, Institute of Cardiovascular Physiology and Pathophysiology, LMU Munich, 82152 Planegg-Martinsried, Germany
| | - Elisabeth Deindl
- Walter-Brendel-Centre of Experimental Medicine, University Hospital, LMU Munich, 81377 Munich, Germany; (K.K.); (N.S.); (S.B.); (S.R.); (A.-K.K.); (M.L.); (B.U.S.)
- Biomedical Center, Institute of Cardiovascular Physiology and Pathophysiology, LMU Munich, 82152 Planegg-Martinsried, Germany
- Correspondence: ; Tel.: +49-89-2180-76504
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Contribution of the Potassium Channels K V1.3 and K Ca3.1 to Smooth Muscle Cell Proliferation in Growing Collateral Arteries. Cells 2020; 9:cells9040913. [PMID: 32276492 PMCID: PMC7226779 DOI: 10.3390/cells9040913] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 03/21/2020] [Accepted: 04/03/2020] [Indexed: 12/20/2022] Open
Abstract
Collateral artery growth (arteriogenesis) involves the proliferation of vascular endothelial cells (ECs) and smooth muscle cells (SMCs). Whereas the proliferation of ECs is directly related to shear stress, the driving force for arteriogenesis, little is known about the mechanisms of SMC proliferation. Here we investigated the functional relevance of the potassium channels KV1.3 and KCa3.1 for SMC proliferation in arteriogenesis. Employing a murine hindlimb model of arteriogenesis, we found that blocking KV1.3 with PAP-1 or KCa3.1. with TRAM-34, both interfered with reperfusion recovery after femoral artery ligation as shown by Laser-Doppler Imaging. However, only treatment with PAP-1 resulted in a reduced SMC proliferation. qRT-PCR results revealed an impaired downregulation of α smooth muscle-actin (αSM-actin) and a repressed expression of fibroblast growth factor receptor 1 (Fgfr1) and platelet derived growth factor receptor b (Pdgfrb) in growing collaterals in vivo and in primary murine arterial SMCs in vitro under KV1.3. blockade, but not when KCa3.1 was blocked. Moreover, treatment with PAP-1 impaired the mRNA expression of the cell cycle regulator early growth response-1 (Egr1) in vivo and in vitro. Together, these data indicate that KV1.3 but not KCa3.1 contributes to SMC proliferation in arteriogenesis.
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Extracellular RNA released due to shear stress controls natural bypass growth by mediating mechanotransduction in mice. Blood 2020; 134:1469-1479. [PMID: 31501155 DOI: 10.1182/blood.2019001392] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 08/27/2019] [Indexed: 12/19/2022] Open
Abstract
Fluid shear stress in the vasculature is the driving force for natural bypass growth, a fundamental endogenous mechanism to counteract the detrimental consequences of vascular occlusive disease, such as stroke or myocardial infarction. This process, referred to as "arteriogenesis," relies on local recruitment of leukocytes, which supply growth factors to preexisting collateral arterioles enabling them to grow. Although several mechanosensing proteins have been identified, the series of mechanotransduction events resulting in local leukocyte recruitment is not understood. In a mouse model of arteriogenesis (femoral artery ligation), we found that endothelial cells release RNA in response to increased fluid shear stress and that administration of RNase inhibitor blocking plasma RNases improved perfusion recovery. In contrast, treatment with bovine pancreatic RNase A or human recombinant RNase1 interfered with leukocyte recruitment and collateral artery growth. Our results indicated that extracellular RNA (eRNA) regulated leukocyte recruitment by engaging vascular endothelial growth factor receptor 2 (VEGFR2), which was confirmed by intravital microscopic studies in a murine cremaster model of inflammation. Moreover, we found that release of von Willebrand factor (VWF) as a result of shear stress is dependent on VEGFR2. Blocking VEGFR2, RNase application, or VWF deficiency interfered with platelet-neutrophil aggregate formation, which is essential for initiating the inflammatory process in arteriogenesis. Taken together, the results show that eRNA is released from endothelial cells in response to shear stress. We demonstrate this extracellular nucleic acid as a critical mediator of mechanotransduction by inducing the liberation of VWF, thereby initiating the multistep inflammatory process responsible for arteriogenesis.
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Chaigneau E, Roche M, Charpak S. Unbiased Analysis Method for Measurement of Red Blood Cell Size and Velocity With Laser Scanning Microscopy. Front Neurosci 2019; 13:644. [PMID: 31316334 PMCID: PMC6610068 DOI: 10.3389/fnins.2019.00644] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 06/05/2019] [Indexed: 12/28/2022] Open
Abstract
Two-photon laser scanning microscopy is widely used to measure blood hemodynamics in brain blood vessels. Still, the algorithms used so far to extract red blood cell (RBC) size and velocity from line-scan acquisitions have ignored the extent to which scanning speed influences the measurements. Here, we used a theoretical approach that takes into account the velocity and direction of both scanning mirrors and RBCs during acquisition to provide an algorithm that measures the real RBC size and velocity. We validate our approach in brain vessels of anesthetized mice, and demonstrate that it corrects online measurement errors that can reach several 10s of percent as well as data previously acquired. To conclude, our analysis allows unbiased comparisons of blood hemodynamic parameters from brain capillaries and large vessels in control and pathological animal models.
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Affiliation(s)
| | | | - Serge Charpak
- INSERM U1128, Laboratory of Neurophysiology and New Microscopy, Université Paris Descartes, Paris, France
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Is there a Chance to Promote Arteriogenesis by DPP4 Inhibitors Even in Type 2 Diabetes? A Critical Review. Cells 2018; 7:cells7100181. [PMID: 30360455 PMCID: PMC6210696 DOI: 10.3390/cells7100181] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 10/08/2018] [Accepted: 10/18/2018] [Indexed: 12/18/2022] Open
Abstract
Cardiovascular diseases (CVD) are still the prevailing cause of death not only in industrialized countries, but even worldwide. Type 2 diabetes mellitus (type 2 DM) and hyperlipidemia, a metabolic disorder that is often associated with diabetes, are major risk factors for developing CVD. Recently, clinical trials proved the safety of gliptins in treating patients with type 2 DM. Gliptins are dipeptidyl-peptidase 4 (DPP4/CD26) inhibitors, which stabilize glucagon-like peptide-1 (GLP-1), thereby increasing the bioavailability of insulin. Moreover, blocking DPP4 results in increased levels of stromal cell derived factor 1 (SDF-1). SDF-1 has been shown in pre-clinical animal studies to improve heart function and survival after myocardial infarction, and to promote arteriogenesis, the growth of natural bypasses, compensating for the function of an occluded artery. Clinical trials, however, failed to demonstrate a superiority of gliptins compared to placebo treated type 2 DM patients in terms of cardiovascular (CV) outcomes. This review highlights the function of DPP4 inhibitors in type 2 DM, and in treating cardiovascular diseases, with special emphasis on arteriogenesis. It critically addresses the potency of currently available gliptins and gives rise to hope by pointing out the most relevant questions that need to be resolved.
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