1
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Callewaert B, Gsell W, Lox M, Backes WH, Jones EAV, Himmelreich U. Intravoxel incoherent motion as a surrogate marker of perfused vascular density in rat brain. NMR Biomed 2024:e5148. [PMID: 38556903 DOI: 10.1002/nbm.5148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 02/21/2024] [Accepted: 02/22/2024] [Indexed: 04/02/2024]
Abstract
Intravoxel incoherent motion (IVIM) MRI has emerged as a valuable technique for the assessment of tissue characteristics and perfusion. However, there is limited knowledge about the relationship between IVIM-derived measures and changes at the level of the vascular network. In this study, we investigated the potential use of IVIM MRI as a noninvasive tool for measuring changes in cerebral vascular density. Variations in quantitative immunohistochemical measurements of the vascular density across different regions in the rat brain (cortex, corpus callosum, hippocampus, thalamus, and hypothalamus) were related to the pseudo-diffusion coefficient D* and the flowing blood fraction f in healthy Wistar rats. We assessed whether region-wise differences in the vascular density are reflected by variations in the IVIM measurements and found a significant positive relationship with the pseudo-diffusion coefficient (p < 0.05, β = 0.24). The effect of cerebrovascular alterations, such as blood-brain barrier (BBB) disruption on the perfusion-related IVIM parameters, is not well understood. Therefore, we investigated the effect of BBB disruption on the IVIM measures in a rat model of metabolic and vascular comorbidities (ZSF1 obese rat) and assessed whether this affects the relationship between the cerebral vascular density and the noninvasive IVIM measurements. We observed increased vascular permeability without detecting any differences in diffusivity, suggesting that BBB leakage is present before changes in the tissue integrity. We observed no significant difference in the relationship between cerebral vascular density and the IVIM measurements in our model of comorbidities compared with healthy normotensive rats.
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Affiliation(s)
- Bram Callewaert
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology (CMVB), KU Leuven, Leuven, Belgium
- Department of Imaging and Pathology, Biomedical MRI Unit, KU Leuven, Leuven, Belgium
| | - Willy Gsell
- Department of Imaging and Pathology, Biomedical MRI Unit, KU Leuven, Leuven, Belgium
| | - Marleen Lox
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology (CMVB), KU Leuven, Leuven, Belgium
| | - Walter H Backes
- Departments of Neurology and Radiology and Nuclear Medicine, Institute for Cardiovascular Diseases (CARIM), Maastricht University Medical Center, Maastricht, The Netherlands
- Department of Radiology and Nuclear Medicine, Institute for Mental Health & Neuroscience (MHeNs), Maastricht University Medical Center, Maastricht, The Netherlands
| | - Elizabeth A V Jones
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology (CMVB), KU Leuven, Leuven, Belgium
- Department of Cardiology, Institute for Cardiovascular Diseases (CARIM), Maastricht University, Maastricht, The Netherlands
| | - Uwe Himmelreich
- Department of Imaging and Pathology, Biomedical MRI Unit, KU Leuven, Leuven, Belgium
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2
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Meyers S, Lox M, Kraisin S, Liesenborghs L, Martens CP, Frederix L, Van Bruggen S, Crescente M, Missiakas D, Baatsen P, Vanassche T, Verhamme P, Martinod K. Neutrophils Protect Against Staphylococcus aureus Endocarditis Progression Independent of Extracellular Trap Release. Arterioscler Thromb Vasc Biol 2023; 43:267-285. [PMID: 36453281 PMCID: PMC9869964 DOI: 10.1161/atvbaha.122.317800] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Accepted: 11/22/2022] [Indexed: 12/05/2022]
Abstract
BACKGROUND Infective endocarditis (IE) is characterized by an infected thrombus at the heart valves. How bacteria bypass the immune system and cause these thrombi remains unclear. Neutrophils releasing NETs (neutrophil extracellular traps) lie at this interface between host defense and coagulation. We aimed to determine the role of NETs in IE immunothrombosis. METHODS We used a murine model of Staphylococcus aureus endocarditis in which IE is provoked on inflamed heart valves and characterized IE thrombus content by immunostaining identifying NETs. Antibody-mediated neutrophil depletion and neutrophil-selective PAD4 (peptidylarginine deiminase 4)-knockout mice were used to clarify the role of neutrophils and NETs, respectively. S. aureus mutants deficient in key virulence factors related to immunothrombosis (nucleases or staphylocoagulases) were investigated. RESULTS Neutrophils releasing NETs were present in infected thrombi and within cellular infiltrates in the surrounding vasculature. Neutrophil depletion increased occurrence of IE, whereas neutrophil-selective impairment of NET formation did not alter IE occurrence. Absence of S. aureus nuclease, which degrades NETs, did not affect endocarditis outcome. In contrast, absence of staphylocoagulases (coagulase and von Willebrand factor binding protein) led to improved survival, decreased bacteremia, smaller infiltrates, and decreased tissue destruction. Significantly more NETs were present in these vegetations, which correlated with decreased bacteria and cell death in the adjacent vascular wall. CONCLUSIONS Neutrophils protect against IE independent of NET release. Absence of S. aureus coagulases, but not nucleases, reduced IE severity and increased NET levels. Staphylocoagulase-induced fibrin likely hampers NETs from constraining infection and the resultant tissue damage, a hallmark of valve destruction in IE.
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Affiliation(s)
- Severien Meyers
- Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences (S.M., M.L., S.K., L.L., C.P.M., L.F., S.V.B., T.V., P.V., K.M.), KU Leuven, Belgium
| | - Marleen Lox
- Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences (S.M., M.L., S.K., L.L., C.P.M., L.F., S.V.B., T.V., P.V., K.M.), KU Leuven, Belgium
| | - Sirima Kraisin
- Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences (S.M., M.L., S.K., L.L., C.P.M., L.F., S.V.B., T.V., P.V., K.M.), KU Leuven, Belgium
| | - Laurens Liesenborghs
- Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences (S.M., M.L., S.K., L.L., C.P.M., L.F., S.V.B., T.V., P.V., K.M.), KU Leuven, Belgium
| | - Caroline P. Martens
- Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences (S.M., M.L., S.K., L.L., C.P.M., L.F., S.V.B., T.V., P.V., K.M.), KU Leuven, Belgium
| | - Liesbeth Frederix
- Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences (S.M., M.L., S.K., L.L., C.P.M., L.F., S.V.B., T.V., P.V., K.M.), KU Leuven, Belgium
| | - Stijn Van Bruggen
- Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences (S.M., M.L., S.K., L.L., C.P.M., L.F., S.V.B., T.V., P.V., K.M.), KU Leuven, Belgium
| | - Marilena Crescente
- Department of Life Sciences, Manchester Metropolitan University, United Kingdom (M.C.)
| | | | - Pieter Baatsen
- Electron Microscopy-Platform of the VIB Bio Imaging Core and VIB Center for Brain and Disease Research (P.B.), KU Leuven, Belgium
| | - Thomas Vanassche
- Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences (S.M., M.L., S.K., L.L., C.P.M., L.F., S.V.B., T.V., P.V., K.M.), KU Leuven, Belgium
| | - Peter Verhamme
- Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences (S.M., M.L., S.K., L.L., C.P.M., L.F., S.V.B., T.V., P.V., K.M.), KU Leuven, Belgium
| | - Kimberly Martinod
- Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences (S.M., M.L., S.K., L.L., C.P.M., L.F., S.V.B., T.V., P.V., K.M.), KU Leuven, Belgium
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3
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Daems M, Liesenborghs L, Boudewijns R, Simmonds SJ, Kraisin S, Van Wauwe J, Cuijpers I, Raman J, Geuens N, Buyten TV, Lox M, Verhamme P, Van Linthout S, Martinod K, Heymans S, Tschöpe C, Neyts J, Jones EAV. SARS-CoV-2 infection causes prolonged cardiomyocyte swelling and inhibition of HIF1α translocation in an animal model COVID-19. Front Cardiovasc Med 2022; 9:964512. [PMID: 36324747 PMCID: PMC9618878 DOI: 10.3389/fcvm.2022.964512] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 09/20/2022] [Indexed: 11/16/2022] Open
Abstract
Recovered COVID-19 patients often display cardiac dysfunction, even after a mild infection. Most current histological results come from patients that are hospitalized and therefore represent more severe outcomes than most COVID-19 patients face. To overcome this limitation, we investigated the cardiac effects of SARS-CoV-2 infection in a hamster model. SARS-CoV-2 infected hamsters developed diastolic dysfunction after recovering from COVID-19. Histologically, increased cardiomyocyte size was present at the peak of viral load and remained at all time points investigated. As this increase is too rapid for hypertrophic remodeling, we found instead that the heart was oedemic. Moreover, cardiomyocyte swelling is associated with the presence of ischemia. Fibrin-rich microthrombi and pericyte loss were observed at the peak of viral load, resulting in increased HIF1α in cardiomyocytes. Surprisingly, SARS-CoV-2 infection inhibited the translocation of HIF1α to the nucleus both in hamster hearts, in cultured cardiomyocytes, as well as in an epithelial cell line. We propose that the observed diastolic dysfunction is the consequence of cardiac oedema, downstream of microvascular cardiac ischemia. Additionally, our data suggest that inhibition of HIF1α translocation could contribute to an exaggerated response upon SARS-CoV-2 infection.
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Affiliation(s)
- Margo Daems
- Centre for Molecular and Vascular Biology, KU Leuven, Leuven, Belgium
| | - Laurens Liesenborghs
- Centre for Molecular and Vascular Biology, KU Leuven, Leuven, Belgium
- Laboratory of Virology and Chemotherapy, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, KU Leuven, Leuven, Belgium
| | - Robbert Boudewijns
- Laboratory of Virology and Chemotherapy, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, KU Leuven, Leuven, Belgium
| | | | - Sirima Kraisin
- Centre for Molecular and Vascular Biology, KU Leuven, Leuven, Belgium
| | - Jore Van Wauwe
- Centre for Molecular and Vascular Biology, KU Leuven, Leuven, Belgium
| | - Ilona Cuijpers
- Centre for Molecular and Vascular Biology, KU Leuven, Leuven, Belgium
- Department of Cardiology, CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, Netherlands
| | - Jana Raman
- Centre for Molecular and Vascular Biology, KU Leuven, Leuven, Belgium
| | - Nadèche Geuens
- Centre for Molecular and Vascular Biology, KU Leuven, Leuven, Belgium
| | - Tina Van Buyten
- Laboratory of Virology and Chemotherapy, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, KU Leuven, Leuven, Belgium
| | - Marleen Lox
- Centre for Molecular and Vascular Biology, KU Leuven, Leuven, Belgium
| | - Peter Verhamme
- Centre for Molecular and Vascular Biology, KU Leuven, Leuven, Belgium
| | - Sophie Van Linthout
- Virchow Clinic, Berlin Institute of Health Center for Regenerative Therapies (BCRT), Charité - University Medicine Berlin, Berlin, Germany
- German Center for Cardiovascular Research (DZHK), Berlin, Germany
| | - Kimberly Martinod
- Centre for Molecular and Vascular Biology, KU Leuven, Leuven, Belgium
| | - Stephane Heymans
- Centre for Molecular and Vascular Biology, KU Leuven, Leuven, Belgium
- Department of Cardiology, CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, Netherlands
| | - Carsten Tschöpe
- Virchow Clinic, Berlin Institute of Health Center for Regenerative Therapies (BCRT), Charité - University Medicine Berlin, Berlin, Germany
- German Center for Cardiovascular Research (DZHK), Berlin, Germany
- Department of Cardiology and Pneumology, Charité - University Medicine Berlin, Berlin, Germany
| | - Johan Neyts
- Laboratory of Virology and Chemotherapy, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, KU Leuven, Leuven, Belgium
| | - Elizabeth A. V. Jones
- Centre for Molecular and Vascular Biology, KU Leuven, Leuven, Belgium
- Department of Cardiology, CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, Netherlands
- *Correspondence: Elizabeth A. V. Jones
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4
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Van den Eynde J, Jacquemyn X, Cloet N, Noé D, Gillijns H, Lox M, Gsell W, Himmelreich U, Luttun A, McCutcheon K, Janssens S, Oosterlinck W. Arteriovenous Fistulae in Chronic Kidney Disease and the Heart: Physiological, Histological, and Transcriptomic Characterization of a Novel Rat Model. J Am Heart Assoc 2022; 11:e027593. [PMID: 36205249 DOI: 10.1161/jaha.122.027593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background Arteriovenous fistulae (AVFs) are the gold standard for vascular access in those requiring hemodialysis but may put an extra hemodynamic stress on the cardiovascular system. The complex interactions between the heart, kidney, and AVFs remain incompletely understood. Methods and Results We characterized a novel rat model of five-sixths partial nephrectomy (NX) and AVFs. NX induced increases in urea, creatinine, and hippuric acid. The addition of an AVF (AVF+NX) further increased urea and a number of uremic toxins such as trimethylamine N-oxide and led to increases in cardiac index, left and right ventricular volumes, and right ventricular mass. Plasma levels of uremic toxins correlated well with ventricular morphology and function. Heart transcriptomes identified altered expression of 8 genes following NX and 894 genes following AVF+NX, whereas 290 and 1431 genes were altered in the kidney transcriptomes, respectively. Gene ontology and Kyoto Encyclopedia of Genes and Genomes analysis revealed gene expression changes related to cell division and immune activation in both organs, suppression of ribosomes and transcriptional activity in the heart, and altered renin-angiotensin signaling as well as chronodisruption in the kidney. All except the latter were worsened in AVF+NX compared with NX. Conclusions Inflammation and organ dysfunction in chronic kidney disease are exacerbated following AVF creation. Furthermore, our study provides important information for the discovery of novel biomarkers and therapeutic targets in the management of cardiorenal syndrome.
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Affiliation(s)
| | | | - Nicolas Cloet
- Department of Cardiovascular Sciences KU Leuven Leuven Belgium
| | - Dries Noé
- Department of Cardiovascular Sciences KU Leuven Leuven Belgium
| | - Hilde Gillijns
- Department of Cardiovascular Sciences KU Leuven Leuven Belgium
| | - Marleen Lox
- Department of Cardiovascular Sciences KU Leuven Leuven Belgium
| | - Willy Gsell
- MoSAIC, Biomedical MRI, Department of Imaging and Pathology KU Leuven Leuven Belgium
| | - Uwe Himmelreich
- MoSAIC, Biomedical MRI, Department of Imaging and Pathology KU Leuven Leuven Belgium
| | - Aernout Luttun
- Department of Cardiovascular Sciences KU Leuven Leuven Belgium.,Endothelial Cell Biology Unit, Center for Molecular and Vascular Biology KU Leuven Leuven Belgium
| | - Keir McCutcheon
- Department of Cardiology Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle University Newcastle United Kingdom
| | - Stefan Janssens
- Department of Cardiovascular Sciences KU Leuven Leuven Belgium.,Department of Cardiovascular Diseases University Hospitals Leuven Leuven Belgium
| | - Wouter Oosterlinck
- Department of Cardiovascular Sciences KU Leuven Leuven Belgium.,Department of Cardiovascular Diseases University Hospitals Leuven Leuven Belgium
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5
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Li LH, Liesenborghs L, Wang L, Lox M, Yakass MB, Jansen S, Rosales Rosas AL, Zhang X, Thibaut HJ, Teuwen D, Neyts J, Delang L, Dallmeier K. Biodistribution and environmental safety of a live-attenuated YF17D-vectored SARS-CoV-2 vaccine candidate. Mol Ther Methods Clin Dev 2022; 25:215-224. [PMID: 35313504 PMCID: PMC8925082 DOI: 10.1016/j.omtm.2022.03.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Accepted: 03/14/2022] [Indexed: 11/06/2022]
Abstract
New platforms are needed for the design of novel prophylactic vaccines and advanced immune therapies. Live-attenuated yellow fever vaccine YF17D serves as a vector for several licensed vaccines and platform for novel candidates. On the basis of YF17D, we developed an exceptionally potent COVID-19 vaccine candidate called YF-S0. However, use of such live RNA viruses raises safety concerns, such as adverse events linked to original YF17D (yellow fever vaccine-associated neurotropic disease [YEL-AND] and yellow fever vaccine-associated viscerotropic disease [YEL-AVD]). In this study, we investigated the biodistribution and shedding of YF-S0 in hamsters. Likewise, we introduced hamsters deficient in signal transducer and activator of transcription 2 (STAT2) signaling as a new preclinical model of YEL-AND/AVD. Compared with YF17D, YF-S0 showed improved safety with limited dissemination to brain and visceral tissues, absent or low viremia, and no shedding of infectious virus. Considering that yellow fever virus is transmitted by Aedes mosquitoes, any inadvertent exposure to the live recombinant vector via mosquito bites is to be excluded. The transmission risk of YF-S0 was hence compared with readily transmitting YF-Asibi strain and non-transmitting YF17D vaccine, with no evidence for productive infection of mosquitoes. The overall favorable safety profile of YF-S0 is expected to translate to other vaccines based on the same YF17D platform.
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Affiliation(s)
- Li-Hsin Li
- KU Leuven, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, Laboratory of Virology and Chemotherapy, Molecular Vaccinology and Vaccine Discovery Team, 3000 Leuven, Belgium
| | - Laurens Liesenborghs
- KU Leuven, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, Laboratory of Virology and Chemotherapy, Molecular Vaccinology and Vaccine Discovery Team, 3000 Leuven, Belgium.,Institute of Tropical Medicine, Department of Clinical Sciences, Outbreak Research Team, 2000 Antwerp, Belgium
| | - Lanjiao Wang
- KU Leuven, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, Laboratory of Virology and Chemotherapy, Mosquito Virology Team, 3000 Leuven, Belgium
| | - Marleen Lox
- KU Leuven, Department of Cardiovascular Sciences, Centre for Molecular and Vascular Biology, 3000 Leuven, Belgium
| | - Michael Bright Yakass
- KU Leuven, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, Laboratory of Virology and Chemotherapy, Molecular Vaccinology and Vaccine Discovery Team, 3000 Leuven, Belgium.,University of Ghana, Department of Biochemistry, Cell and Molecular Biology, the West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), Legon, Accra 1181, Ghana
| | - Sander Jansen
- KU Leuven, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, Laboratory of Virology and Chemotherapy, Molecular Vaccinology and Vaccine Discovery Team, 3000 Leuven, Belgium
| | - Ana Lucia Rosales Rosas
- KU Leuven, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, Laboratory of Virology and Chemotherapy, Mosquito Virology Team, 3000 Leuven, Belgium
| | - Xin Zhang
- KU Leuven, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, Laboratory of Virology and Chemotherapy, Molecular Vaccinology and Vaccine Discovery Team, 3000 Leuven, Belgium
| | - Hendrik Jan Thibaut
- KU Leuven, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, Translational Platform Virology and Chemotherapy (TPVC), 3000 Leuven, Belgium
| | - Dirk Teuwen
- KU Leuven, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, Laboratory of Virology and Chemotherapy, Molecular Vaccinology and Vaccine Discovery Team, 3000 Leuven, Belgium
| | - Johan Neyts
- KU Leuven, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, Laboratory of Virology and Chemotherapy, Molecular Vaccinology and Vaccine Discovery Team, 3000 Leuven, Belgium
| | - Leen Delang
- KU Leuven, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, Laboratory of Virology and Chemotherapy, Mosquito Virology Team, 3000 Leuven, Belgium
| | - Kai Dallmeier
- KU Leuven, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, Laboratory of Virology and Chemotherapy, Molecular Vaccinology and Vaccine Discovery Team, 3000 Leuven, Belgium
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6
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Jacques N, Meyers S, Leeten K, Lox M, Debuisson M, Delvenne P, Nchimi A, Kuijpers MJ, Vanassche T, Martinod K, Verhamme P, Lancellotti P, Oury C. Ticagrelor prevents infective endocarditis by mitigating Staphylococcus aureus virulence. Archives of Cardiovascular Diseases Supplements 2022. [DOI: 10.1016/j.acvdsp.2022.04.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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7
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de Haan W, Dheedene W, Apelt K, Décombas-Deschamps S, Vinckier S, Verhulst S, Conidi A, Deffieux T, Staring MW, Vandervoort P, Caluwé E, Lox M, Mannaerts I, Takagi T, Jaekers J, Berx G, Haigh J, Topal B, Zwijsen A, Higashi Y, van Grunsven LA, van IJcken WFJ, Mulugeta E, Tanter M, Lebrin FPG, Huylebroeck D, Luttun A. Endothelial Zeb2 preserves the hepatic angioarchitecture and protects against liver fibrosis. Cardiovasc Res 2021; 118:1262-1275. [PMID: 33909875 PMCID: PMC8953454 DOI: 10.1093/cvr/cvab148] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 04/26/2021] [Indexed: 02/06/2023] Open
Abstract
Aims Hepatic capillaries are lined with specialized liver sinusoidal endothelial cells (LSECs) which support macromolecule passage to hepatocytes and prevent fibrosis by keeping hepatic stellate cells (HSCs) quiescent. LSEC specialization is co-determined by transcription factors. The zinc-finger E-box-binding homeobox (Zeb)2 transcription factor is enriched in LSECs. Here, we aimed to elucidate the endothelium-specific role of Zeb2 during maintenance of the liver and in liver fibrosis. Methods and results To study the role of Zeb2 in liver endothelium we generated EC-specific Zeb2 knock-out (ECKO) mice. Sequencing of liver EC RNA revealed that deficiency of Zeb2 results in prominent expression changes in angiogenesis-related genes. Accordingly, the vascular area was expanded and the presence of pillars inside ECKO liver vessels indicated that this was likely due to increased intussusceptive angiogenesis. LSEC marker expression was not profoundly affected and fenestrations were preserved upon Zeb2 deficiency. However, an increase in continuous EC markers suggested that Zeb2-deficient LSECs are more prone to dedifferentiation, a process called ‘capillarization’. Changes in the endothelial expression of ligands that may be involved in HSC quiescence together with significant changes in the expression profile of HSCs showed that Zeb2 regulates LSEC–HSC communication and HSC activation. Accordingly, upon exposure to the hepatotoxin carbon tetrachloride (CCl4), livers of ECKO mice showed increased capillarization, HSC activation, and fibrosis compared to livers from wild-type littermates. The vascular maintenance and anti-fibrotic role of endothelial Zeb2 was confirmed in mice with EC-specific overexpression of Zeb2, as the latter resulted in reduced vascularity and attenuated CCl4-induced liver fibrosis. Conclusion Endothelial Zeb2 preserves liver angioarchitecture and protects against liver fibrosis. Zeb2 and Zeb2-dependent genes in liver ECs may be exploited to design novel therapeutic strategies to attenuate hepatic fibrosis.
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Affiliation(s)
- Willeke de Haan
- Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | - Wouter Dheedene
- Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | - Katerina Apelt
- Department of Internal Medicine (Nephrology), Einthoven Laboratory for Experimental Vascular Medicine. Leiden University Medical Center, . Leiden, The Netherlands
| | - Sofiane Décombas-Deschamps
- Physics for Medicine Paris, Inserm, CNRS, ESPCI Paris, Paris Sciences et Lettres University, Paris, France
| | - Stefan Vinckier
- Department of Oncology, Laboratory of Angiogenesis and Vascular Metabolism, KU Leuven, Leuven, Belgium.,Laboratory of Angiogenesis and Vascular Metabolism, Center for Cancer Biology, Vlaams Instituut voor Biotechnologie (VIB), Leuven, Belgium
| | - Stefaan Verhulst
- Liver Cell Biology research group, Vrije Universiteit Brussel, Brussels, Belgium
| | - Andrea Conidi
- Department of Cell Biology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Thomas Deffieux
- Physics for Medicine Paris, Inserm, CNRS, ESPCI Paris, Paris Sciences et Lettres University, Paris, France
| | - Michael W Staring
- Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | - Petra Vandervoort
- Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | - Ellen Caluwé
- Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | - Marleen Lox
- Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | - Inge Mannaerts
- Liver Cell Biology research group, Vrije Universiteit Brussel, Brussels, Belgium
| | - Tsuyoshi Takagi
- Department of Disease Model, Institute of Developmental Research, Aichi Developmental Disability Center, Aichi, Japan
| | | | - Geert Berx
- Molecular and Cellular Oncology Laboratory, Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium.,Cancer Research Institute Ghent (CRIG), Ghent, Belgium
| | - Jody Haigh
- Department of Pharmacology and Therapeutics, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada.,Research Institute in Oncology and Hematology, Cancer Care Manitoba, Winnipeg, Manitoba, Canada
| | - Baki Topal
- Abdominal Surgery, UZ Leuven, Leuven, Belgium
| | - An Zwijsen
- Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | - Yujiro Higashi
- Department of Disease Model, Institute of Developmental Research, Aichi Developmental Disability Center, Aichi, Japan
| | - Leo A van Grunsven
- Liver Cell Biology research group, Vrije Universiteit Brussel, Brussels, Belgium
| | - Wilfred F J van IJcken
- Department of Cell Biology, Erasmus University Medical Center, Rotterdam, The Netherlands.,Center for Biomics-Genomics, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Eskeatnaf Mulugeta
- Department of Cell Biology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Mickael Tanter
- Physics for Medicine Paris, Inserm, CNRS, ESPCI Paris, Paris Sciences et Lettres University, Paris, France
| | - Franck P G Lebrin
- Department of Internal Medicine (Nephrology), Einthoven Laboratory for Experimental Vascular Medicine. Leiden University Medical Center, . Leiden, The Netherlands.,Physics for Medicine Paris, Inserm, CNRS, ESPCI Paris, Paris Sciences et Lettres University, Paris, France
| | - Danny Huylebroeck
- Department of Cell Biology, Erasmus University Medical Center, Rotterdam, The Netherlands.,Department of Development and Regeneration, KU Leuven, Leuven, Belgium
| | - Aernout Luttun
- Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
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Liesenborghs L, Meyers S, Lox M, Criel M, Claes J, Peetermans M, Trenson S, Vande Velde G, Vanden Berghe P, Baatsen P, Missiakas D, Schneewind O, Peetermans WE, Hoylaerts MF, Vanassche T, Verhamme P. Staphylococcus aureus endocarditis: distinct mechanisms of bacterial adhesion to damaged and inflamed heart valves. Eur Heart J 2020; 40:3248-3259. [PMID: 30945735 DOI: 10.1093/eurheartj/ehz175] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2018] [Revised: 02/03/2019] [Accepted: 03/12/2019] [Indexed: 11/12/2022] Open
Abstract
AIMS The pathogenesis of endocarditis is not well understood resulting in unsuccessful attempts at prevention. Clinical observations suggest that Staphylococcus aureus infects either damaged or inflamed heart valves. Using a newly developed endocarditis mouse model, we therefore studied the initial adhesion of S. aureus in both risk states. METHODS AND RESULTS Using 3D confocal microscopy, we examined the adhesion of fluorescent S. aureus to murine aortic valves. To mimic different risk states we either damaged the valves with a surgically placed catheter or simulated valve inflammation by local endothelium activation. We used von Willebrand factor (VWF) gene-deficient mice, induced platelet and fibrinogen depletion and used several S. aureus mutant strains to investigate the contribution of both host and bacterial factors in early bacterial adhesion. Both cardiac valve damage and inflammation predisposed to endocarditis, but by distinct mechanisms. Following valve damage, S. aureus adhered directly to VWF and fibrin, deposited on the damaged valve. This was mediated by Sortase A-dependent adhesins such as VWF-binding protein and Clumping factor A. Platelets did not contribute. In contrast, upon cardiac valve inflammation, widespread endothelial activation led to endothelial cell-bound VWF release. This recruited large amounts of platelets, capturing S. aureus to the valve surface. Here, neither fibrinogen, nor Sortase A were essential. CONCLUSION Cardiac valve damage and inflammation predispose to S. aureus endocarditis via distinct mechanisms. These findings may have important implications for the development of new preventive strategies, as some interventions might be effective in one risk state, but not in the other.
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Affiliation(s)
- Laurens Liesenborghs
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, KU Leuven, Herestraat 49, Leuven, Belgium
| | - Severien Meyers
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, KU Leuven, Herestraat 49, Leuven, Belgium
| | - Marleen Lox
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, KU Leuven, Herestraat 49, Leuven, Belgium
| | - Maarten Criel
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, KU Leuven, Herestraat 49, Leuven, Belgium
| | - Jorien Claes
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, KU Leuven, Herestraat 49, Leuven, Belgium
| | - Marijke Peetermans
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, KU Leuven, Herestraat 49, Leuven, Belgium
| | - Sander Trenson
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, KU Leuven, Herestraat 49, Leuven, Belgium
| | - Greetje Vande Velde
- Department of Imaging & Pathology, Biomedical MRI/Molecular Small Animal Imaging Center, KU Leuven, Leuven, Belgium
| | - Pieter Vanden Berghe
- Department of Chronic Diseases, Metabolism and Ageing, Lab for Enteric NeuroScience, TARGID, KU Leuven, Leuven, Belgium
| | - Pieter Baatsen
- VIB Bio Imaging Core and VIB-KU Leuven, Center for Brain and Disease Research, KU Leuven, Leuven, Belgium
| | | | - Olaf Schneewind
- Department of Microbiology, University of Chicago, Chicago, IL, USA
| | | | - Marc F Hoylaerts
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, KU Leuven, Herestraat 49, Leuven, Belgium
| | - Thomas Vanassche
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, KU Leuven, Herestraat 49, Leuven, Belgium
| | - Peter Verhamme
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, KU Leuven, Herestraat 49, Leuven, Belgium
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9
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Peetermans M, Meyers S, Liesenborghs L, Vanhoorelbeke K, De Meyer SF, Vandenbriele C, Lox M, Hoylaerts MF, Martinod K, Jacquemin M, Vanassche T, Verhamme P. Von Willebrand factor and ADAMTS13 impact on the outcome of Staphylococcus aureus sepsis. J Thromb Haemost 2020; 18:722-731. [PMID: 31758651 DOI: 10.1111/jth.14686] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 11/18/2019] [Indexed: 01/02/2023]
Abstract
BACKGROUND Previous clinical evidence correlates levels of von Willebrand factor (VWF) and its cleaving protease ADAMTS13 with outcome in septic patients. No previous studies addressed if VWF and ADAMTS13 affected the outcome of Staphylococcus aureus sepsis. OBJECTIVES We studied the role of VWF and ADAMTS13 in S. aureus sepsis both in patients and in mice. METHODS VWF levels and ADAMTS13 activity levels were measured in plasma samples from 89 S. aureus bacteremia patients by chemiluminescent assays and were correlated with clinical sepsis outcome parameters. In wild-type mice and mice deficient in VWF and ADAMTS13, we investigated the outcome of S. aureus sepsis and quantified bacterial clearance and organ microthrombi. RESULTS In patients with S. aureus bloodstream infections, high VWF levels and low ADAMTS13 activity levels correlated with disease severity and with parameters of inflammation and disseminated intravascular coagulation. In septic mice, VWF deficiency attenuated mortality, whereas ADAMTS13 deficiency increased mortality. Bacterial clearance was enhanced in VWF-deficient mice. The differences in mortality for the studied genotypes were associated with differential loads of organ microthrombi in both liver and kidneys. CONCLUSIONS In conclusion, this study reports the consistent relation of VWF, ADAMTS13 and their ratio to disease severity in patients and mice with S. aureus sepsis. Targeting VWF multimers and/or the relative ADAMTS13 deficiency that occurs in sepsis should be explored as a potential new therapeutic target in S. aureus endovascular infections.
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Affiliation(s)
- Marijke Peetermans
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, University of Leuven, Leuven, Belgium
| | - Severien Meyers
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, University of Leuven, Leuven, Belgium
| | - Laurens Liesenborghs
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, University of Leuven, Leuven, Belgium
| | - Karen Vanhoorelbeke
- Laboratory for Thrombosis Research, University of Leuven campus Kulak Kortrijk, Kortrijk, Belgium
| | - Simon F De Meyer
- Laboratory for Thrombosis Research, University of Leuven campus Kulak Kortrijk, Kortrijk, Belgium
| | - Christophe Vandenbriele
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, University of Leuven, Leuven, Belgium
| | - Marleen Lox
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, University of Leuven, Leuven, Belgium
| | - Marc F Hoylaerts
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, University of Leuven, Leuven, Belgium
| | - Kimberly Martinod
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, University of Leuven, Leuven, Belgium
| | - Marc Jacquemin
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, University of Leuven, Leuven, Belgium
| | - Thomas Vanassche
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, University of Leuven, Leuven, Belgium
| | - Peter Verhamme
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, University of Leuven, Leuven, Belgium
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Vercalsteren E, Vranckx C, Frederix L, Lox M, Lijnen HR, Scroyen I, Hemmeryckx B. Advanced-age C57BL/6JRj mice do not develop obesity upon western-type diet exposure. Adipocyte 2019; 8:105-113. [PMID: 30860940 PMCID: PMC6768272 DOI: 10.1080/21623945.2019.1590893] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 02/06/2019] [Accepted: 02/13/2019] [Indexed: 12/16/2022] Open
Abstract
Obesity has become a global health-threat for every age group. It is well known that young mice (10-12 weeks of age) fed a western-type diet (WD) become obese and develop higher cholesterol levels and liver steatosis whereas insulin sensitivity is reduced. Less is known, however, about the effect of a WD on advanced-age mice. Therefore, 10 week-old (young) and 22 month-old (advanced-age), male C57BL/6JRj mice were kept on either a WD or a control diet (SFD) for 15 weeks. In contrast to young mice, advanced-age mice on WD did not show a higher body weight or adipose tissue (AT)-masses, suggesting a protection against diet-induced obesity. Furthermore, plasma adiponectin and leptin levels were not affected upon WD-feeding. A WD, however, did induce more hepatic lipid accumulation as well as increased hepatic expression of the macrophage marker F4/80, in advanced-age mice. There were no significant differences in mRNA levels of uncoupling protein-1 or F4/80 in brown AT (BAT) or of several intestinal integrity markers in colon suggesting that the protection against obesity is not due to excessive BAT or to impaired intestinal absorption of fat. Thus, advanced-age mice, in contrast to their younger counterparts, appeared to be protected against diet-induced obesity.
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Affiliation(s)
- Ellen Vercalsteren
- Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | - Christine Vranckx
- Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | - Liesbeth Frederix
- Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | - Marleen Lox
- Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | - H. Roger Lijnen
- Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | - Ilse Scroyen
- Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | - Bianca Hemmeryckx
- Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
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11
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Meyers S, Liesenborghs L, Lox M, De Meyer SF, Vanassche T, Verhamme P, Martinod K. P3660Investigating the role of neutrophils and NETs in staphylococcus aureus endocarditis. Eur Heart J 2019. [DOI: 10.1093/eurheartj/ehz745.0515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background/Introduction
Infective endocarditis (IE) remains one of the deadliest cardiac diseases. Despite optimal antibiotic and surgical treatment, still one in three patients do not survive Staphylococcus aureus (S. aureus) IE. In order to cause this disease, bacteria need to first overcome shear stress and adhere to cardiac valves. Secondly, they need be able to progress into a complex lesion. Previously, we have shown that S. aureus adheres to cardiac valves via platelets and von Willebrand factor. However, the process of progression from initial bacterial adhesion to a complex vegetation, particularly how bacteria bypass the immune system and thrive in the host environment, remains unclear.
Purpose
We aimed to determine the role of neutrophils and neutrophil extracellular traps (NETs) in IE progression using a novel mouse model.
Methods
We intravenously injected mice with S. aureus and locally stimulated the endothelium with histamine, resulting in IE lesions that originate on inflamed heart valves. After three days we determined the development of IE on the aortic valves with Gram staining and echocardiography. We investigated the presence of NETs in 14 mice by immunostaining for citrullinated histone H3 (H3Cit), extracellular DNA, and myeloperoxidase. Of these 14 mice, 9 developed endocarditis. In a separate set of experiments, we investigated the role of neutrophils in IE development by injecting a neutrophil-depleting or control antibody 24h before surgery.
Results
Echocardiography revealed real IE lesions attached on inflamed aortic valves. Mice with endocarditis had significantly (P=0.005) more detectable H3Cit (9/9) than those without (1/5). More specifically, four mice had H3Cit+ neutrophils within thrombi, indicating early NETosis. Seven mice had an extracellular H3Cit staining pattern within the thrombus. These extracellular H3Cit-positive regions were associated with DNA and myeloperoxidase, indicating the presence of a network of NETs. When we depleted neutrophils, mice developed significantly more endocarditis (7/16 vs. 1/15, P=0.03).
Conclusion
Endocarditis lesions contained NETs or neutrophils undergoing NETosis, and neutrophil depletion led to increased IE incidence. Further investigating these two players in IE could potentially provide new strategies to combat this deadly disease.
Acknowledgement/Funding
FWO SB
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Affiliation(s)
| | | | - M Lox
- KU Leuven, Leuven, Belgium
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12
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Feng Y, Hemmeryckx B, Frederix L, Lox M, Wu J, Heggermont W, Lu HR, Gallacher D, Oyen R, Lijnen HR, Ni Y. Monitoring reperfused myocardial infarction with delayed left ventricular systolic dysfunction in rabbits by longitudinal imaging. Quant Imaging Med Surg 2018; 8:754-769. [PMID: 30306056 DOI: 10.21037/qims.2018.09.05] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Background An experimental imaging platform for longitudinal monitoring and evaluation of cardiac morphology-function changes has been long desired. We sought to establish such a platform by using a rabbit model of reperfused myocardial infarction (MI) that develops chronic left ventricle systolic dysfunction (LVSD) within 7 weeks. Methods Fifty-five New Zeeland white (NZW) rabbits received sham-operated or 60-min left circumflex coronary artery (LCx) ligation followed by reperfusion. Cardiac magnetic resonance imaging (cMRI), transthoracic echocardiography (echo), and blood samples were collected at baseline, in acute (48 hours or 1 week) and chronic (7 weeks) stage subsequent to MI for in vivo assessment of infarct size, cardiac morphology, LV function, and myocardial enzymes. Seven weeks post MI, animals were sacrificed and heart tissues were processed for histopathological staining. Results The success rate of surgical operation was 87.27%. The animal mortality rates were 12.7% and 3.6% both in acute and chronic stage separately. Serum levels of the myocardial enzyme cardiac Troponin T (cTnT) were significantly increased in MI rabbits as compared with sham animals after 4 hours of operation (P<0.05). According to cardiac morphology and function changes, 4 groups could be distinguished: sham rabbits (n=12), and MI rabbits with no (MI_NO_LVSD; n=10), moderate (MI_M_LVSD; n=9) and severe (MI_S_LVSD; n=15) LVSD. No significant differences in cardiac function or wall thickening between sham and MI_NO_LVSD rabbits were observed at both stages using both cMRI and echo methods. cMRI data showed that MI_M_LVSD rabbits exhibited a reduction of ejection fraction (EF) and an increase in end-systolic volume (ESV) at the acute phase, while at the chronic stage these parameters did not change further. Moreover, in MI_S_LVSD animals, these observations were more striking at the acute stage followed by a further decline in EF and increase in ESV at the chronic stage. Lateral wall thickening determined by cMRI was significantly decreased in MI_M_LVSD versus MI_NO_LVSD animals at both stages (P<0.05). As for MI_S_LVSD versus MI_M_LVSD rabbits, the thickening of anterior, inferior and lateral walls was significantly more decreased at both stages (P<0.05). Echo confirmed the findings of cMRI. Furthermore, these in vivo outcomes including those from vivid cine cMRI could be supported by exactly matched ex vivo histomorphological evidences. Conclusions Our findings indicate that chronic LVSD developed over time after surgery-induced MI in rabbits can be longitudinally evaluated using non-invasive imaging techniques and confirmed by the entire-heart-slice histomorphology. This experimental LVSD platform in rabbits may interest researchers in the field of experimental cardiology and help strengthen drug development and translational research for the management of cardiovascular diseases.
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Affiliation(s)
- Yuanbo Feng
- Radiology, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| | - Bianca Hemmeryckx
- Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | - Liesbeth Frederix
- Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | - Marleen Lox
- Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | - Jun Wu
- Ultrasound Diagnostic department, the second affiliated hospital of Dalian Medical University, Dalian 116000, China
| | - Ward Heggermont
- Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | - Hua Rong Lu
- Translational Sciences, Safety Pharmacology Research, Janssen Research & Development, Janssen Pharmaceutical NV, Beerse, Belgium
| | - David Gallacher
- Translational Sciences, Safety Pharmacology Research, Janssen Research & Development, Janssen Pharmaceutical NV, Beerse, Belgium
| | - Raymond Oyen
- Radiology, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| | - H Roger Lijnen
- Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | - Yicheng Ni
- Radiology, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
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13
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Hemmeryckx B, Feng Y, Frederix L, Lox M, Trenson S, Vreeken R, Lu HR, Gallacher D, Ni Y, Lijnen HR. Evaluation of cardiac arrhythmic risks using a rabbit model of left ventricular systolic dysfunction. Eur J Pharmacol 2018; 832:145-155. [PMID: 29782862 DOI: 10.1016/j.ejphar.2018.05.026] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 05/17/2018] [Accepted: 05/17/2018] [Indexed: 12/13/2022]
Abstract
Patients with heart disease have a higher risk to develop cardiac arrhythmias, either spontaneously or drug-induced. In this study, we have used a rabbit model of myocardial infarction (MI) with severe left ventricular systolic dysfunction (LVSD) to study potential drug-induced cardiac risks with N-(piperidin-2-ylmethyl)-2,5-bis(2,2,2-trifluoroethoxy)benzamide (flecainide). Upon ligation of the left circumflex arteries, male New Zealand White rabbits developed a large MI and moderate or severe LVSD 7 weeks after surgery, in comparison to SHAM-operated animals. Subsequently, animals were exposed to escalating doses of flecainide (0.25-4 mg/kg) or solvent. Electrocardiograms (ECG) were recorded before surgery, 1 and 7 weeks after surgery and continuously during the drug protocol. The ECG biomarker iCEB (index of Cardio-Electrophysiological Balance = QT/QRS ratio) was calculated. During the ECG recording at week 1 and week 7 post MI, rabbits had no spontaneous cardiac arrhythmias. When rabbits were exposed to escalating doses of flecainide, 2 out of 5 rabbits with MI and moderate LVSD versus 0 out of 5 solvent-treated rabbits developed arrhythmias, such as ventricular tachycardia/ventricular fibrillation. These were preceded by a marked decrease of iCEB just before the onset (from 4.09 to 2.42 and from 5.56 to 2.25, respectively). Furthermore, 1 out of 5 MI rabbits with moderate LVSD and 1 out of 7 MI rabbits with severe LVSD developed total atrioventricular block after flecainide infusion and died. This rabbit model of MI and severe LVSD may be useful for preclinical evaluation of drug (similar mechanism as flecainide)-induced arrhythmic risks, which might be predicted by iCEB.
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Affiliation(s)
- Bianca Hemmeryckx
- Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium.
| | - Yuanbo Feng
- Radiology, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium.
| | - Liesbeth Frederix
- Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium.
| | - Marleen Lox
- Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium.
| | - Sander Trenson
- Cardiology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium.
| | - Rob Vreeken
- Metabolomics, Pharmacokinetics, Dynamics and Metabolism Discovery Sciences, Janssen Pharmaceutical NV, Beerse, Belgium.
| | - Hua Rong Lu
- Translational Sciences, Safety Pharmacology Research, Janssen Research & Development, Janssen Pharmaceutical NV, Beerse, Belgium.
| | - David Gallacher
- Translational Sciences, Safety Pharmacology Research, Janssen Research & Development, Janssen Pharmaceutical NV, Beerse, Belgium.
| | - Yicheng Ni
- Radiology, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium.
| | - H Roger Lijnen
- Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium.
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14
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Criel M, Izzi B, Vandenbriele C, Liesenborghs L, Van kerckhoven S, Lox M, Cludts K, Jones EA, Vanassche T, Verhamme P, Hoylaerts M. Absence of Pear1 does not affect murine platelet function in vivo. Thromb Res 2016; 146:76-83. [DOI: 10.1016/j.thromres.2016.08.026] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 08/09/2016] [Accepted: 08/24/2016] [Indexed: 11/29/2022]
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15
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Liesenborghs L, Peetermans M, Claes J, Veloso TR, Vandenbriele C, Criel M, Lox M, Peetermans WE, Heilbronner S, de Groot PG, Vanassche T, Hoylaerts MF, Verhamme P. Shear-Resistant Binding to von Willebrand Factor Allows Staphylococcus lugdunensis to Adhere to the Cardiac Valves and Initiate Endocarditis. J Infect Dis 2016; 213:1148-56. [PMID: 26743845 DOI: 10.1093/infdis/jiv773] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 12/19/2015] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Staphylococcus lugdunensis is an emerging cause of endocarditis. To cause endovascular infections, S. lugdunensis requires mechanisms to overcome shear stress. We investigated whether platelets and von Willebrand factor (VWF) mediate bacterial adhesion to the vessel wall and the cardiac valves under flow. METHODS S. lugdunensis binding to VWF, collagen, and endothelial cells was studied in a parallel flow chamber in the absence and presence of platelets. In vivo adhesion of S. lugdunensis was evaluated in a mouse microvasculature perfusion model and a new mouse model of endocarditis. RESULTS Contrary to other coagulase-negative staphylococci, S. lugdunensis bound to VWF under flow, thus enabling its adhesion to endothelial cells and to the subendothelial matrix. In inflamed vessels of the mesenteric circulation, VWF recruited S. lugdunensis to the vessel wall. In a novel endocarditis mouse model, local inflammation and the resulting release of VWF enabled S. lugdunensis to bind and colonize the heart valves. CONCLUSIONS S. lugdunensis binds directly to VWF, which proved to be vital for withstanding shear forces and for its adhesion to the vessel wall and cardiac valves. This mechanism explains why S. lugdunensis causes more-aggressive infections, including endocarditis, compared with other coagulase-negative staphylococci.
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Affiliation(s)
| | | | - Jorien Claes
- Center for Molecular and Vascular Biology, KU Leuven, Belgium
| | | | | | - Maarten Criel
- Center for Molecular and Vascular Biology, KU Leuven, Belgium
| | - Marleen Lox
- Center for Molecular and Vascular Biology, KU Leuven, Belgium
| | | | - Simon Heilbronner
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Germany
| | - Philip G de Groot
- Laboratory of Clinical Chemistry and Haematology, University Medical Center, Utrecht, The Netherlands
| | | | | | - Peter Verhamme
- Center for Molecular and Vascular Biology, KU Leuven, Belgium
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16
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Claes J, Liesenborghs L, Lox M, Verhamme P, Vanassche T, Peetermans M. In Vitro and In Vivo Model to Study Bacterial Adhesion to the Vessel Wall Under Flow Conditions. J Vis Exp 2015:e52862. [PMID: 26131651 PMCID: PMC4545207 DOI: 10.3791/52862] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In order to cause endovascular infections and infective endocarditis, bacteria need to be able to adhere to the vessel wall while being exposed to the shear stress of flowing blood. To identify the bacterial and host factors that contribute to vascular adhesion of microorganisms, appropriate models that study these interactions under physiological shear conditions are needed. Here, we describe an in vitro flow chamber model that allows to investigate bacterial adhesion to different components of the extracellular matrix or to endothelial cells, and an intravital microscopy model that was developed to directly visualize the initial adhesion of bacteria to the splanchnic circulation in vivo. These methods can be used to identify the bacterial and host factors required for the adhesion of bacteria under flow. We illustrate the relevance of shear stress and the role of von Willebrand factor for the adhesion of Staphylococcus aureus using both the in vitro and in vivo model.
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Affiliation(s)
- Jorien Claes
- Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences, KU Leuven;
| | - Laurens Liesenborghs
- Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences, KU Leuven
| | - Marleen Lox
- Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences, KU Leuven
| | - Peter Verhamme
- Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences, KU Leuven
| | - Thomas Vanassche
- Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences, KU Leuven
| | - Marijke Peetermans
- Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences, KU Leuven
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17
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Muthuramu I, Lox M, Jacobs F, De Geest B. Permanent ligation of the left anterior descending coronary artery in mice: a model of post-myocardial infarction remodelling and heart failure. J Vis Exp 2014. [PMID: 25489995 DOI: 10.3791/52206] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Heart failure is a syndrome in which the heart fails to pump blood at a rate commensurate with cellular oxygen requirements at rest or during stress. It is characterized by fluid retention, shortness of breath, and fatigue, in particular on exertion. Heart failure is a growing public health problem, the leading cause of hospitalization, and a major cause of mortality. Ischemic heart disease is the main cause of heart failure. Ventricular remodelling refers to changes in structure, size, and shape of the left ventricle. This architectural remodelling of the left ventricle is induced by injury (e.g., myocardial infarction), by pressure overload (e.g., systemic arterial hypertension or aortic stenosis), or by volume overload. Since ventricular remodelling affects wall stress, it has a profound impact on cardiac function and on the development of heart failure. A model of permanent ligation of the left anterior descending coronary artery in mice is used to investigate ventricular remodelling and cardiac function post-myocardial infarction. This model is fundamentally different in terms of objectives and pathophysiological relevance compared to the model of transient ligation of the left anterior descending coronary artery. In this latter model of ischemia/reperfusion injury, the initial extent of the infarct may be modulated by factors that affect myocardial salvage following reperfusion. In contrast, the infarct area at 24 hr after permanent ligation of the left anterior descending coronary artery is fixed. Cardiac function in this model will be affected by 1) the process of infarct expansion, infarct healing, and scar formation; and 2) the concomitant development of left ventricular dilatation, cardiac hypertrophy, and ventricular remodelling. Besides the model of permanent ligation of the left anterior descending coronary artery, the technique of invasive hemodynamic measurements in mice is presented in detail.
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Affiliation(s)
- Ilayaraja Muthuramu
- Department of Cardiovascular Sciences, Centre for Molecular and Vascular Biology, Catholic University of Leuven
| | - Marleen Lox
- Department of Cardiovascular Sciences, Centre for Molecular and Vascular Biology, Catholic University of Leuven
| | - Frank Jacobs
- Department of Cardiovascular Sciences, Centre for Molecular and Vascular Biology, Catholic University of Leuven
| | - Bart De Geest
- Department of Cardiovascular Sciences, Centre for Molecular and Vascular Biology, Catholic University of Leuven;
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18
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Merchiers P, Dooren T, Van der Auwera I, Abulrob A, Lauwereys M, Roland B, Borghraef P, Decruy T, Lox M, Hoogenboom HR, Wera S, Stanimirovic D, Haard H, Leuven F. P4–245: Nanobodies™ targeting amyloid beta as potential therapeutics for Alzheimer's disease. Alzheimers Dement 2006. [DOI: 10.1016/j.jalz.2006.05.1985] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
| | - Tom Dooren
- Experimental Genetics GroupDept. Human GeneticsKULeuvenB-3000LeuvenBelgium
| | | | | | | | | | - Peter Borghraef
- Experimental Genetics GroupDept. Human GeneticsKULeuvenB-3000LeuvenBelgium
| | | | | | | | | | | | | | - Fred Leuven
- Experimental Genetics GroupDept. Human GeneticsKULeuvenB-3000LeuvenBelgium
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19
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Larmann J, Schmidt C, Gammelin H, Van Aken HK, Frenzel T, Lanckohr C, Lox M, Boese N, Jurk K, Theilmeier G. Intercellular adhesion molecule-1 inhibition attenuates neurologic and hepatic damage after resuscitation in mice. Anesthesiology 2006; 103:1149-55. [PMID: 16306726 DOI: 10.1097/00000542-200512000-00008] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Cardiac arrest and cardiopulmonary resuscitation may result in multiorgan damage after global hypoxia due to neutrophil recruitment. Patients display all signs of a systemic inflammatory response syndrome. Reducing neutrophil recruitment may thus preserve organ function. METHODS Mice were subjected to cardiac arrest and resuscitation. CD18/CD11b expression on circulating neutrophils was assessed by flow cytometry. Intercellular adhesion molecule-1 expression was analyzed by Western blot and immunofluorescence. Neutrophil recruitment was quantified by immunohistochemistry. Neurologic function was assessed by a balance test. For liver and kidney function, plasma alanine aminotransferase activity and creatinine concentrations were determined. To reduce neutrophil recruitment, mice received 100 microg anti-intercellular adhesion molecule-1 antibody intraperitoneally. RESULTS Resuscitation led to severe hypoxia, acidosis, and hypercarbia. Adhesion molecule expression and neutrophil recruitment were increased in the liver, kidney, and brain. Neurologic performance was impaired 24 h after cardiac arrest. Creatinine and alanine aminotransferase concentrations were significantly increased. Immunoneutralization of intercellular adhesion molecule-1 attenuated neutrophil influx in the liver along with alanine aminotransferase activity, whereas creatinine concentrations and neutrophil influx in the kidney remained unchanged. Neurologic function was improved in the treatment group. CONCLUSIONS Global hypoxia induces activation of the endothelium in the brain, liver, and kidney. The resulting damage to the brain and liver are due to infiltration of neutrophils, whereas kidney damage is not, because reduction of neutrophil recruitment after cardiopulmonary resuscitation improves recovery of neurologic and hepatic but not renal function. Inhibition of intercellular adhesion molecule-1 after global hypoxia may be beneficial in patients experiencing cardiac arrest and resuscitation.
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Affiliation(s)
- Jan Larmann
- Department of Anesthesiology and IZKF, University Hospital Münster, University of Münster, Vesaliusweg 2-4, 48149 Münster, Germany
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20
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Theilmeier G, Verhamme P, Dymarkowski S, Beck H, Bernar H, Lox M, Janssens S, Herregods MC, Verbeken E, Collen D, Plate K, Flameng W, Holvoet P. Hypercholesterolemia in minipigs impairs left ventricular response to stress: association with decreased coronary flow reserve and reduced capillary density. Circulation 2002; 106:1140-6. [PMID: 12196342 DOI: 10.1161/01.cir.0000026805.41747.54] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Hypercholesterolemia induces functional and structural changes of the microvasculature and reduces coronary flow reserve in humans and experimental animals. The effect of hypercholesterolemia on left ventricular (LV) function in the absence of coronary stenosis is, however, unknown. Our objective was therefore to assess the effect of hypercholesterolemia and cholesterol withdrawal on LV function in the presence of advanced coronary plaques that do not cause stenosis. METHODS AND RESULTS Twenty-eight minipigs on cholesterol diet for 34 weeks and 16 control pigs were studied. Seven hypercholesterolemic pigs were withdrawn from the diet for 26 weeks. LV function was assessed with cine-MRI, myocardial blood flow with colored microspheres, and capillary density with immunohistochemistry, and microvascular endothelial cell apoptosis with terminal dUTP nick-end labeling staining. Hypercholesterolemia (17+/-8 versus 268+/-150 versus 12+/-10 mg/dL LDL cholesterol, control versus hypercholesterolemic versus cholesterol withdrawal; P<0.001) induced atherosclerosis but not stenosis in the left coronary artery. Baseline cardiac output, ejection fraction, and stroke volume were similar in control and hypercholesterolemic pigs. In dobutamine stress test, cardiac output (P<0.05) and stroke volume (P<0.01) were lower in hypercholesterolemic pigs compared with controls. The impaired response to dobutamine was reversible by dietary cholesterol withdrawal. Hypercholesterolemia reduced endomyocardial coronary flow reserve (P<0.01) and capillary density (P<0.05) and induced capillary endothelial cell apoptosis. Hypercholesterolemic pigs failed to reduce vascular resistance in response to increased LV workload and pharmacological vasodilation. CONCLUSION LDL hypercholesterolemia in minipigs impaired LV response to dobutamine stress in the absence of coronary stenosis.
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Affiliation(s)
- Gregor Theilmeier
- Center for Molecular and Vascular Biology, Katholieke Universiteit Leuven, Leuven, Belgium
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21
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Tanoue Y, Herijgers P, Meuris B, Verbeken E, Leunens V, Lox M, Flameng W. Ischemic preconditioning reduces unloaded myocardial oxygen consumption in an in-vivo sheep model. Cardiovasc Res 2002; 55:633-41. [PMID: 12160961 DOI: 10.1016/s0008-6363(02)00278-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
OBJECTIVE Ischemic preconditioning (IP) describes the adaptation of the myocardium to ischemic stress preceded by short periods of ischemia and reperfusion. However, its cardioprotective mechanisms are not completely understood. We assessed the effect of IP on ventricular energetics in an in-vivo sheep model. METHODS IP was performed in six sheep by three 5 min aortic cross-clamping periods interspersed with 5 min of reperfusion during cardiopulmonary bypass and with six sheep as time-matched controls. Global myocardial ischemia was subsequently achieved by 30 min aortic cross-clamping with left ventricular unloading during normothermic cardiopulmonary bypass. Weaning from cardiopulmonary bypass was performed 40 min after reperfusion. At baseline, after treatment (IP or time-matched cardiopulmonary bypass), and up to 100 min after reperfusion, left ventricular pressure-volume loops were measured using a conductance catheter during a right heart bypass preparation. Contractility, diastolic function, and ventriculo-arterial coupling were evaluated. Ventricular energetics [the relation between myocardial oxygen consumption (MVO(2)) and systolic pressure-volume area (PVA)] was also evaluated. A right heart bypass was instituted to control the preload and to decompress the right ventricle completely, thereby eliminating parallel conductance variation and minimizing the contribution of the right ventricle to MVO(2). RESULTS IP reduced unloaded MVO(2) (PVA-independent MVO(2)). Contractility, diastolic function, and ventriculo-arterial coupling in the IP group were better preserved than in the control group after ischemia-reperfusion. CONCLUSIONS IP reduces unloaded MVO(2), and preserves contractility, diastolic function, and ventriculo-arterial coupling after 30 min global myocardial ischemia in an in-vivo sheep model.
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Affiliation(s)
- Yoshihisa Tanoue
- Center for Experimental Surgery and Anaesthesiology (C.E.H.A.), Cardiovascular Research Unit, Katholieke Universiteit Leuven, Minderbroedersstraat 17, Belgium
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22
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Theilmeier G, Quarck R, Verhamme P, Bochaton-Piallat ML, Lox M, Bernar H, Janssens S, Kockx M, Gabbiani G, Collen D, Holvoet P. Hypercholesterolemia impairs vascular remodelling after porcine coronary angioplasty. Cardiovasc Res 2002; 55:385-95. [PMID: 12123778 DOI: 10.1016/s0008-6363(02)00409-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
OBJECTIVE To assess the effect of hypercholesterolemia on neointima formation and vascular remodelling after porcine coronary angioplasty. METHODS Left anterior descending coronary angioplasty was carried out in five control and 16 age-matched hypercholesterolemic miniature pigs. Vascular remodelling was measured by intravascular ultrasound. Neointima size and composition were assessed by quantitative image analysis. Coronary smooth muscle cells (SMC) from control and diet pigs were collected 1 h after angioplasty for in vitro study of the effect of hypercholesterolemic serum on SMC migration and of macrophage-induced matrix degradation on SMC adhesion. RESULTS Twenty-eight days after angioplasty, lumen increase was 0.08+/-1.7 mm(2) in diet and 2.7+/-2.7 mm(2) (P=0.016) in control pigs. Lumen increase correlated with vascular remodelling (IEL(post)/IEL(pre); R(2)=0.59; P<0.001) and with the circumferential gain relative to the neointima (R(2)=0.32; P<0.01) but not with neointimal area that was similar in control and diet pigs. Circumferential gain correlated with VSMC deposition at the site of the injury (R(2)=0.28; P<0.01) that correlated with organized collagen (R(2)=0.34; P<0.01). The VSMC and collagen content of neointima in diet pigs was lower whereas the macrophage content was higher. Hypercholesterolemic serum and oxidised LDL reduced migration of VSMC from diet pigs. Macrophage-induced degradation of VSMC extracellular matrix reduced VSMC adhesion (P=0.015). CONCLUSION Hypercholesterolemia impairs vascular remodelling of balloon-treated coronary arteries. It decreases VSMC and collagen accumulation at the site of injury. Our in vitro data suggest that this decrease can be due to macrophage-induced matrix degradation and reduced VSMC adhesion and to impaired VSMC migration. Oxidised LDL mimics the inhibitory effect of hypercholesterolemic serum.
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Affiliation(s)
- Gregor Theilmeier
- Center for Molecular and Vascular Biology, Campus Gasthuisberg, O&N, Herestraat 49, B-3000, Leuven, Belgium
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23
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Tanoue Y, Herijgers P, Meuris B, Leunens V, Lox M, Flameng W. Cardioprotective effect of ischemic preconditioning on global myocardial ischemia in a sheep right heart bypass model. Jpn J Thorac Cardiovasc Surg 2002; 50:23-9. [PMID: 11855095 DOI: 10.1007/bf02913482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
OBJECTIVES Ischemic preconditioning has been used to induce the myocardium to adapt to ischemic stress preceded by short periods of ischemia and reperfusion. We used a sheep right heart bypass model with a conductance catheter to assess the cardioprotective effect of ischemic preconditioning on 30-minute normothermic global myocardial ischemia. METHODS Ischemic preconditioning was conducted in 6 sheep in 35-minute aortic cross-clampings interspersed with 5 minutes of reperfusion during cardiopulmonary bypass, with 6 sheep as time-matched controls. Global myocardial ischemia was subsequently achieved in 30-minute aortic cross-clamping with left ventricular unloading during normothermic cardiopulmonary bypass. Weaning from cardiopulmonary bypass was conducted 40 minutes after reperfusion. Before ischemia and 40, 70, and 100 minutes after reperfusion, left ventricular pressure-volume loops were measured using a conductance catheter during right heart bypass preparation. Left ventricular contractility, diastolic function, and mechanical efficiency were then evaluated. Right heart bypass was instituted to control the preload and to decompress the right ventricle completely, thereby eliminating parallel conductance variation. RESULTS No differences in the studied parameters were seen between ischemic-preconditioning and control groups before ischemia. Left ventricular contractility, diastolic function, and mechanical efficiency in the ischemic-preconditioning group were significantly superior to those in the control group after reperfusion. CONCLUSIONS Ischemic preconditioning attenuates postischemic myocardial dysfunction in a sheep model using 30-minute unloaded normothermic global myocardial ischemia. Ischemic preconditioning would thus be clinically significant when the ischemic damage is severe.
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Affiliation(s)
- Yoshihisa Tanoue
- Department of Cardiac Surgery, Katholieke Universiteit Leuven, Belgium
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24
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Holvoet P, Peeters K, Lund-Katz S, Mertens A, Verhamme P, Quarck R, Stengel D, Lox M, Deridder E, Bernar H, Nickel M, Theilmeier G, Ninio E, Phillips MC. Arg123-Tyr166 domain of human ApoA-I is critical for HDL-mediated inhibition of macrophage homing and early atherosclerosis in mice. Arterioscler Thromb Vasc Biol 2001; 21:1977-83. [PMID: 11742873 DOI: 10.1161/hq1201.100221] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Atherosclerosis was studied in apolipoprotein E (apoE) knockout mice expressing human apolipoprotein A-I (apoA-I) or an apoA-I/apolipoprotein A-II (apoA-II) chimera in which the Arg123-Tyr166 central domain of apoA-I was substituted with the Ser12-Ala75 segment of apoA-II. High density lipoprotein (HDL) cholesterol levels were identical in apoA-I and apoA-I/apoA-II mice, but at 4 months, plaques were 2.7-fold larger in the aortic root of the apoA-I/apoA-II mice (P<0.01). The macrophage-to-smooth muscle cell ratio of lesions was 2.1-fold higher in apo-I/apoA-II mice than in apoA-I mice (P<0.01). This was due to a 2.7-fold higher (P<0.001) in vivo macrophage homing in the aortic root of apoA-I/apoA-II mice. Plasma platelet-activating factor acetyl hydrolase activity was lower (P<0.01) in apoA-I/apoA-II mice, resulting in increased oxidative stress, as evidenced by the higher titer of antibodies against oxidized low density lipoprotein (P<0.01). Increased oxidative stress resulted in increased stimulation of ex vivo macrophage adhesion by apoA-I/apoA-II beta-very low density lipoprotein and decreased inhibition of beta-very low density lipoprotein-induced adhesion by HDL from apoA-I/apoA-II mice. The cellular cholesterol efflux capacity of HDL from apoA-I/apoA-II mice was very similar to that of apoA-I mice. Thus, the Arg123-Tyr166 central domain of apoA-I is critical for reducing oxidative stress, macrophage homing, and early atherosclerosis in apoE knockout mice independent of its role in HDL production and cholesterol efflux.
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Affiliation(s)
- P Holvoet
- Center for Experimental Surgery and Anesthesiology, Katholieke Universiteit Leuven, Leuven, Belgium.
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25
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Quarck R, De Geest B, Stengel D, Mertens A, Lox M, Theilmeier G, Michiels C, Raes M, Bult H, Collen D, Van Veldhoven P, Ninio E, Holvoet P. Adenovirus-Mediated Gene Transfer of Human Platelet-Activating Factor–Acetylhydrolase Prevents Injury-Induced Neointima Formation and Reduces Spontaneous Atherosclerosis in Apolipoprotein E–Deficient Mice. Circulation 2001; 103:2495-500. [PMID: 11369691 DOI: 10.1161/01.cir.103.20.2495] [Citation(s) in RCA: 148] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background
—Atherosclerosis is characterized by an early inflammatory response involving proinflammatory mediators such as platelet-activating factor (PAF)-like phospholipids, which are inactivated by PAF-acetylhydrolase (PAF-AH). The effect of adenovirus-mediated expression of PAF-AH on injury-induced neointima formation and spontaneous atherosclerosis was studied in apolipoprotein E–deficient mice.
Methods and Results
—Intravenous administration of an adenovirus (5×10
8
plaque-forming units) directing liver-specific expression of human PAF-AH resulted in a 3.5-fold increase of plasma PAF-AH activity at day 7 (
P
<0.001); this was associated with a 2.4- and 2.3-fold decrease in malondialdehyde-modified LDL autoantibodies and the lysophosphatidylcholine/phosphatidylcholine ratio, respectively (
P
<0.001 for both). Non-HDL and HDL cholesterol levels in
PAF-AH
–treated mice were similar to those of control virus-treated mice. Seven days after virus injection, endothelial denudation of the common left carotid artery was induced with a guidewire. Neointima formation was assessed 18 days later.
PAF-AH
gene transfer reduced oxidized lipoproteins by 82% (
P
<0.001), macrophages by 69% (
P
=0.006), and smooth muscle cells by 84% (
P
=0.002) in the arterial wall. This resulted in a 77% reduction (
P
<0.001) of neointimal area. Six weeks after adenovirus-mediated gene transfer, spontaneous atherosclerotic lesions in the aortic root were analyzed.
PAF-AH
gene transfer reduced atherosclerotic lesions by 42% (
P
=0.02) in male mice, whereas a nonsignificant 14% reduction was observed in female mice. Basal and PAF-AH activity after gene transfer were higher in male mice than in female mice (
P
=0.01 and
P
=0.04, respectively).
Conclusions
—Gene transfer of
PAF-AH
inhibited injury-induced neointima formation and spontaneous atherosclerosis in apolipoprotein E–deficient mice. Our data indicate that PAF-AH, by reducing oxidized lipoprotein accumulation, is a potent protective enzyme against atherosclerosis.
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Affiliation(s)
- R Quarck
- Center for Molecular and Vascular Biology, Department of Experimental Surgery and Anesthesiology, Katholieke Universiteit Leuven, Leuven, Belgium
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26
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Theilmeier G, De Geest B, Van Veldhoven PP, Stengel D, Michiels C, Lox M, Landeloos M, Chapman MJ, Ninio E, Collen D, Himpens B, Holvoet P. HDL-associated PAF-AH reduces endothelial adhesiveness in apoE-/- mice. FASEB J 2000; 14:2032-9. [PMID: 11023987 DOI: 10.1096/fj.99-1029com] [Citation(s) in RCA: 108] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Macrophage infiltration into the subendothelial space at lesion prone sites is the primary event in atherogenesis. Inhibition of macrophage homing might therefore prevent atherosclerosis. Since HDL levels are inversely correlated with cardiovascular risk, their effect on macrophage homing was assessed in apoE-deficient (apoE-/-) mice. Overexpression of human apolipoprotein AI in apoE-/- mice increased HDL levels 3-fold and reduced macrophage accumulation in an established assay of leukocyte homing to aortic root endothelium 3.2-fold (P<0.005). This was due to reduced in vivo betaVLDL oxidation, reduced betaVLDL triggered endothelial cytosolic Ca2+ signaling through PAF-like bioactivity, lower ICAM-1 and VCAM-1 expression, and diminished ex vivo leukocyte adhesion. Adenoviral gene transfer of human PAF-acetylhydrolase (PAF-AH) in apoE-/- mice increased PAF-AH activity 1.5-fold (P<0.001), reduced betaVLDL-induced ex vivo macrophage adhesion 3.5-fold (P<0.01), and reduced in vivo macrophage homing 2.6-fold (P<0.02). These inhibitory effects were observed in the absence of increased HDL cholesterol levels. In conclusion, HDL reduces macrophage homing to endothelium by reducing oxidative stress via its associated PAF-AH activity. This protective mechanism is independent of the function of HDL as cholesterol acceptor. Modulation of lipoprotein oxidation by PAF-AH may prevent leukocyte recruitment to the vessel wall, a key feature in atherogenesis.
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Affiliation(s)
- G Theilmeier
- Center for Molecular and Vascular Biology, KU Leuven, Leuven, Belgium
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27
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De Geest B, Stengel D, Landeloos M, Lox M, Le Gat L, Collen D, Holvoet P, Ninio E. Effect of overexpression of human apo A-I in C57BL/6 and C57BL/6 apo E-deficient mice on 2 lipoprotein-associated enzymes, platelet-activating factor acetylhydrolase and paraoxonase. Comparison of adenovirus-mediated human apo A-I gene transfer and human apo A-I transgenesis. Arterioscler Thromb Vasc Biol 2000; 20:E68-75. [PMID: 11031226 DOI: 10.1161/01.atv.20.10.e68] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Various mechanisms may contribute to the antiatherogenic potential of apolipoprotein A-I (apo A-I) and high density lipoproteins (HDLs). Therefore, the effect of adenovirus-mediated human apo A-I gene transfer or human apo A-I transgenesis on platelet-activating factor acetylhydrolase (PAF-AH) and arylesterase/paraoxonase (PON1) was studied in C57BL/6 and C57BL/6 apo E(-/-) mice. Human apo A-I transgenesis in C57BL/6 mice resulted in a 4.2-fold (P<0.0001) increase of PAF-AH and a 1.7-fold (P=0.0012) increase of PON1 activity. The apo E deficiency was associated with a 1.6-fold (P=0.008) lower PAF-AH and a 2.0-fold (P=0.012) lower PON1 activity. Human apo A-I transgenesis in C57BL/6 apo E(-/-)mice increased PAF-AH and PON1 activity by 2.1-fold (P=0.01) and 2.5-fold (P=0.029), respectively. After adenovirus-mediated gene transfer of human apo A-I into C57BL/6 apo E(-/-)mice, a strong correlation between human apo A-I plasma levels and PAF-AH activity was observed at day 6 (r=0.92, P<0.0001). However, PON1 activity failed to increase, probably as a result of cytokine-mediated inhibition of PON 1 expression. In conclusion, this study indicates that overexpression of human apo A-I increases HDL-associated PAF-AH activity. PON1 activity was also increased in human apo A-I transgenic mice, but not after human apo A-I gene transfer, a result that was probably related to cytokine production induced in the liver by the adenoviral vectors. Increased levels of these HDL-associated enzymes may contribute to the anti-inflammatory and antioxidative potential of HDL and thereby to the protection conferred by HDL against atherothrombosis.
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Affiliation(s)
- B De Geest
- Center for Molecular and Vascular Biology, University of Leuven, Leuven, Belgium
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28
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Holvoet P, De Geest B, Van Linthout S, Lox M, Danloy S, Raes K, Collen D. The Arg123-Tyr166 central domain of human ApoAI is critical for lecithin:cholesterol acyltransferase-induced hyperalphalipoproteinemia and HDL remodeling in transgenic mice. Arterioscler Thromb Vasc Biol 2000; 20:459-66. [PMID: 10669644 DOI: 10.1161/01.atv.20.2.459] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
High density lipoprotein (HDL) metabolism and lecithin:cholesterol acyltransferase (LCAT)-induced HDL remodeling were investigated in transgenic mice expressing human apolipoprotein (apo) AI or an apoAI/apoAII chimera in which the Arg123-Tyr166 domain of apoAI was substituted with the Ser12-Ala75 domain of apoAII. Expression of apoAI and of the apoAI/apoAII chimera resulted in a respective 3. 5-fold and 2.9-fold increase of HDL cholesterol. Human LCAT gene transfer into apoAI-transgenic mice resulted in a 5.1-fold increase of endogenous LCAT activity. This increase was associated with a 2. 4-fold increase of the cholesterol ester-to-free cholesterol ratio of HDL, a shift from HDL(3) to HDL(2), and a 2.4-fold increase of HDL cholesterol levels. Agarose gel electrophoresis revealed that human LCAT gene transfer into human apoAI-transgenic mice resulted in an increase of pre-beta-HDL and of pre-alpha-HDL. In contrast, human LCAT gene transfer did not affect cholesterol levels and HDL distribution profile in mice expressing the apoAI/apoAII chimera. Mouse LCAT did not "see" a difference between wild-type and mutant human apoAI, whereas human LCAT did, thus localizing the species-specific interaction in the central domain of apoAI. In conclusion, the Arg123-Tyr166 central domain of apoAI is not critical for in vivo lipoprotein association. It is, however, critical for LCAT-induced hyperalphalipoproteinemia and HDL remodeling independent of the lipid-binding properties of apoAI.
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Affiliation(s)
- P Holvoet
- Center for Molecular and Vascular Biology, University of Leuven, Leuven, Belgium.
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29
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De Geest B, Van Linthout S, Lox M, Collen D, Holvoet P. Sustained expression of human apolipoprotein A-I after adenoviral gene transfer in C57BL/6 mice: role of apolipoprotein A-I promoter, apolipoprotein A-I introns, and human apolipoprotein E enhancer. Hum Gene Ther 2000; 11:101-12. [PMID: 10646643 DOI: 10.1089/10430340050016193] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Elevation of HDL cholesterol, after adenoviral apolipoprotein A-I (apo A-I) gene transfer, may delay or revert ischemic cardiovascular disease, provided transgene expression is persistent. Previously, we observed transient human apo A-I expression after adenoviral gene transfer with a cytomegalovirus (CMV)-driven construct containing the human apo A-I cDNA. Therefore, the effects of promoters (CMV or 256 base pairs of the human apo A-I promoter), introns of the human apo A-I gene, and the liver-specific human apolipoprotein E (apo E) enhancer on adenovirus-mediated human apo A-I expression were evaluated in C57BL/6 mice. In the presence of the CMV promoter, human apo A-I introns prolonged expression above 20 mg/dl from 14 to 35 days. Addition of one, two, or four copies of the human apo E enhancer in these constructs resulted in a copy-dependent but transient increase in expression for 14 days. The apo A-I promoter induced 3.2-fold lower peak levels of human apo A-I than did the CMV promoter, but insertion of four apo E enhancers in the apo A-I promoter-driven construct resulted in human apo A-I levels above 20 mg/dl for 6 months. The decline between day 6 and day 35 of human apo A-I expression driven by the CMV promoter was due to (1) a 2.5-fold decline in transgene DNA levels that is not observed with apo A-I promoter-driven constructs, and (2) CMV promoter attenuation as evidenced by a 7.6-fold decline in the human apo A-I mRNA/human apo A-I DNA copy number ratio between day 6 and day 35. Hepatotoxicity, as evidenced by up to 10-fold higher serum levels of transaminases on day 6 after gene transfer with CMV promoter-driven constructs than with apo A-I promoter-driven constructs, probably caused the accelerated decline of transgene DNA. In conclusion, gene transfer with an adenovirus comprising the 256-bp apo A-I promoter, the genomic apo A-I DNA, and four apo E enhancers, all of human origin, is associated with low hepatotoxicity and with the absence of promoter shutoff resulting in human apo A-I expression above 20 mg/dl for up to 6 months.
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Affiliation(s)
- B De Geest
- Center for Molecular and Vascular Biology, Leuven, Belgium
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Holvoet P, Danloy S, Deridder E, Lox M, Bernar H, Dhoest A, Collen D. Substitution of the carboxyl-terminal domain of apo AI with apo AII sequences restores the potential of HDL to reduce the progression of atherosclerosis in apo E knockout mice. J Clin Invest 1998; 102:379-85. [PMID: 9664079 PMCID: PMC508896 DOI: 10.1172/jci3038] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
HDL metabolism and atherosclerosis were studied in apo E knockout (KO) mice overexpressing human apo AI, a des- (190-243)-apo AI carboxyl-terminal deletion mutant of human apo AI or an apo AI-(1-189)-apo AII-(12-77) chimera in which the carboxyl-terminal domain of apo AI was substituted with the pair of helices of apo AII. HDL cholesterol levels ranked: apo AI/apo E KO approximately apo AI-(1-189)-apo AII- (12-77)/apo E KO > > des-(190-243)-apo AI/apo E KO > apo E KO mice. Progression of atherosclerosis ranked: apo E KO > des-(190-243)-apo AI/apo E KO > > apo AI-(1-189)- apo AII-(12-77)/apo E KO approximately apo AI/apo E KO mice. Whereas the total capacity to induce cholesterol efflux from lipid-loaded THP-1 macrophages was higher for HDL of mice overexpressing human apo AI or the apo AI/apo AII chimera, the fractional cholesterol efflux rate, expressed in percent cholesterol efflux/microg apolipoprotein/h, for HDL of these mice was similar to that for HDL of mice overexpressing the deletion mutant and for HDL of apo E KO mice. This study demonstrates that the tertiary structure of apo AI, e.g., the number and organization of its helices, and not its amino sequence is essential for protection against atherosclerosis because it determines HDL cholesterol levels and not cholesterol efflux. Amino acid sequences of apo AII, which is considered to be less antiatherogenic, can be used to restore the structure of apo AI and thereby its antiatherogenicity.
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Affiliation(s)
- P Holvoet
- Center for Molecular and Vascular Biology, University of Leuven, Leuven, Belgium.
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