1
|
Katz DH, Tahir UA, Ngo D, Benson MD, Gao Y, Shi X, Nayor M, Keyes MJ, Larson MG, Hall ME, Correa A, Sinha S, Shen D, Herzig M, Yang Q, Robbins JM, Chen ZZ, Cruz DE, Peterson B, Vasan RS, Wang TJ, Wilson JG, Gerszten RE. Multiomic Profiling in Black and White Populations Reveals Novel Candidate Pathways in Left Ventricular Hypertrophy and Incident Heart Failure Specific to Black Adults. CIRCULATION. GENOMIC AND PRECISION MEDICINE 2021; 14:e003191. [PMID: 34019435 PMCID: PMC8497179 DOI: 10.1161/circgen.120.003191] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 05/05/2021] [Indexed: 11/16/2022]
Abstract
BACKGROUND Increased left ventricular (LV) mass is associated with adverse cardiovascular events including heart failure (HF). Both increased LV mass and HF disproportionately affect Black individuals. To understand the underlying mechanisms, we undertook a proteomic screen in a Black cohort and compared the findings to results from a White cohort. METHODS We measured 1305 plasma proteins using the SomaScan platform in 1772 Black participants (mean age, 56 years; 62% women) in JHS (Jackson Heart Study) with LV mass assessed by 2-dimensional echocardiography. Incident HF was assessed in 1600 participants. We then compared protein associations in JHS to those observed in White participants from FHS (Framingham Heart Study; mean age, 54 years; 56% women). RESULTS In JHS, there were 110 proteins associated with LV mass and 13 proteins associated with incident HF hospitalization with false discovery rate <5% after multivariable adjustment. Several proteins showed expected associations with both LV mass and HF, including NT-proBNP (N-terminal pro-B-type natriuretic peptide; β=0.04; P=2×10-8; hazard ratio, 1.48; P=0.0001). The strongest association with LV mass was novel: LKHA4 (leukotriene-A4 hydrolase; β=0.05; P=5×10-15). This association was confirmed on an alternate proteomics platform and further supported by related metabolomic data. Fractalkine/CX3CL1 (C-X3-C Motif Chemokine Ligand 1) showed a novel association with incident HF (hazard ratio, 1.32; P=0.0002). While established biomarkers such as cystatin C and NT-proBNP showed consistent associations in Black and White individuals, LKHA4 and fractalkine were significantly different between the two groups. CONCLUSIONS We identified several novel biological pathways specific to Black adults hypothesized to contribute to the pathophysiologic cascade of LV hypertrophy and incident HF including LKHA4 and fractalkine.
Collapse
Affiliation(s)
- Daniel H. Katz
- Division of Cardiovascular Medicine, Beth Israel Deaconess Medical Center, Boston, MA
| | - Usman A. Tahir
- Division of Cardiovascular Medicine, Beth Israel Deaconess Medical Center, Boston, MA
| | - Debby Ngo
- Division of Cardiovascular Medicine, Beth Israel Deaconess Medical Center, Boston, MA
| | - Mark D. Benson
- Division of Cardiovascular Medicine, Beth Israel Deaconess Medical Center, Boston, MA
| | - Yan Gao
- Univ of Mississippi Medical Center, Jackson, MS
| | - Xu Shi
- Division of Cardiovascular Medicine, Beth Israel Deaconess Medical Center, Boston, MA
| | - Matthew Nayor
- Cardiology Division, Department of Medicine, Massachusetts General Hospital
| | - Michelle J. Keyes
- Division of Cardiovascular Medicine, Beth Israel Deaconess Medical Center, Boston, MA
- Framingham Heart Study, Framingham
| | | | | | | | - Sumita Sinha
- Whitehead Institute for Biomedical Research, Cambridge
| | - Dongxiao Shen
- Division of Cardiovascular Medicine, Beth Israel Deaconess Medical Center, Boston, MA
| | - Matthew Herzig
- Division of Cardiovascular Medicine, Beth Israel Deaconess Medical Center, Boston, MA
| | - Qiong Yang
- Department of Biostatistics, Boston University School of Public Health, Boston, MA
| | - Jeremy M. Robbins
- Division of Cardiovascular Medicine, Beth Israel Deaconess Medical Center, Boston, MA
| | - Zsu-Zsu Chen
- Division of Cardiovascular Medicine, Beth Israel Deaconess Medical Center, Boston, MA
| | - Daniel E. Cruz
- Division of Cardiovascular Medicine, Beth Israel Deaconess Medical Center, Boston, MA
| | - Bennet Peterson
- Division of Cardiovascular Medicine, Beth Israel Deaconess Medical Center, Boston, MA
| | | | - Thomas J. Wang
- Department of Medicine, UT Southwestern Medical Center, Dallas, TX
| | - James G. Wilson
- Division of Cardiovascular Medicine, Beth Israel Deaconess Medical Center, Boston, MA
| | - Robert E. Gerszten
- Division of Cardiovascular Medicine, Beth Israel Deaconess Medical Center, Boston, MA
- Broad Institute of Harvard and MIT, Cambridge, MA
| |
Collapse
|
2
|
Phie J, Thanigaimani S, Golledge J. Systematic Review and Meta-Analysis of Interventions to Slow Progression of Abdominal Aortic Aneurysm in Mouse Models. Arterioscler Thromb Vasc Biol 2021; 41:1504-1517. [PMID: 33567871 DOI: 10.1161/atvbaha.121.315942] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
[Figure: see text].
Collapse
Affiliation(s)
- James Phie
- Queensland Research Centre for Peripheral Vascular Disease, College of Medicine and Dentistry (J.P., S.T., J.G.), James Cook University, Townsville, Australia
| | - Shivshankar Thanigaimani
- Queensland Research Centre for Peripheral Vascular Disease, College of Medicine and Dentistry (J.P., S.T., J.G.), James Cook University, Townsville, Australia
| | - Jonathan Golledge
- Queensland Research Centre for Peripheral Vascular Disease, College of Medicine and Dentistry (J.P., S.T., J.G.), James Cook University, Townsville, Australia.,Australian Institute of Tropical Health and Medicine (J.G.), James Cook University, Townsville, Australia.,Department of Vascular and Endovascular Surgery, Townsville University Hospital, Queensland, Australia (J.G.)
| |
Collapse
|
3
|
Zagrapan B, Eilenberg W, Scheuba A, Klopf J, Brandau A, Story J, Dosch K, Hayden H, Domenig CM, Fuchs L, Schernthaner R, Ristl R, Huk I, Neumayer C, Brostjan C. Complement Factor C5a Is Increased in Blood of Patients with Abdominal Aortic Aneurysm and Has Prognostic Potential for Aneurysm Growth. J Cardiovasc Transl Res 2020; 14:761-769. [PMID: 33332020 PMCID: PMC8397625 DOI: 10.1007/s12265-020-10086-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 11/22/2020] [Indexed: 11/24/2022]
Abstract
In this observational case-control study, circulating levels of complement factors C3a and C5a and leukotriene B4 (LTB4) were analysed in abdominal aortic aneurysm (AAA) patients regarding their association with diagnosis and prognosis. Serum C5a was significantly raised in AAA patients compared to healthy controls—median 84.5 ng/ml (IQR = 37.5 ng/ml) vs. 67.7 ng/ml (IQR = 26.2 ng/ml), p = 0.007—but was not elevated in patients with athero-occlusive disease. Serum C5a levels correlated significantly with the increase in maximum AAA diameter over the following 6 months (r = 0.319, p = 0.021). The median growth in the lowest quartile of C5a (< 70 ng/ml) was 50% less compared to the highest C5a quartile (> 101 ng/ml): 1.0 mm/6 months (IQR = 0.8 mm) vs. 2.0 mm/6 months (IQR = 1.5 mm), p = 0.014. A log-linear mixed model predicted AAA expansion based on current diameter and C5a level. To our knowledge, this is the first study linking complement activation, in particular C5a serum level, with AAA progression.
Collapse
Affiliation(s)
- Branislav Zagrapan
- Department of Surgery: Division of Vascular Surgery and Surgical Research Laboratories, Medical University of Vienna, Vienna General Hospital, Vienna, Austria
| | - Wolf Eilenberg
- Department of Surgery: Division of Vascular Surgery and Surgical Research Laboratories, Medical University of Vienna, Vienna General Hospital, Vienna, Austria
| | - Andreas Scheuba
- Department of Surgery: Division of Vascular Surgery and Surgical Research Laboratories, Medical University of Vienna, Vienna General Hospital, Vienna, Austria
| | - Johannes Klopf
- Department of Surgery: Division of Vascular Surgery and Surgical Research Laboratories, Medical University of Vienna, Vienna General Hospital, Vienna, Austria
| | - Annika Brandau
- Department of Surgery: Division of Vascular Surgery and Surgical Research Laboratories, Medical University of Vienna, Vienna General Hospital, Vienna, Austria
| | - Julia Story
- Department of Surgery: Division of Vascular Surgery and Surgical Research Laboratories, Medical University of Vienna, Vienna General Hospital, Vienna, Austria
| | - Katharina Dosch
- Department of Surgery: Division of Vascular Surgery and Surgical Research Laboratories, Medical University of Vienna, Vienna General Hospital, Vienna, Austria
| | - Hubert Hayden
- Department of Surgery: Division of Vascular Surgery and Surgical Research Laboratories, Medical University of Vienna, Vienna General Hospital, Vienna, Austria
| | - Christoph M Domenig
- Department of Surgery: Division of Vascular Surgery and Surgical Research Laboratories, Medical University of Vienna, Vienna General Hospital, Vienna, Austria
| | - Lukas Fuchs
- Department of Surgery: Division of Vascular Surgery and Surgical Research Laboratories, Medical University of Vienna, Vienna General Hospital, Vienna, Austria
| | - Rüdiger Schernthaner
- Department of Biomedical Imaging and Image Guided Therapy: Division of Cardiovascular and Interventional Radiology, Medical University of Vienna, Vienna General Hospital, Vienna, Austria
| | - Robin Ristl
- Center for Medical Statistics, Informatics, and Intelligent Systems, Medical University of Vienna, Vienna, Austria
| | - Ihor Huk
- Department of Surgery: Division of Vascular Surgery and Surgical Research Laboratories, Medical University of Vienna, Vienna General Hospital, Vienna, Austria
| | - Christoph Neumayer
- Department of Surgery: Division of Vascular Surgery and Surgical Research Laboratories, Medical University of Vienna, Vienna General Hospital, Vienna, Austria
| | - Christine Brostjan
- Department of Surgery: Division of Vascular Surgery and Surgical Research Laboratories, Medical University of Vienna, Vienna General Hospital, Vienna, Austria.
| |
Collapse
|
4
|
Cysteinyl leukotriene receptor 1 antagonism prevents experimental abdominal aortic aneurysm. Proc Natl Acad Sci U S A 2018; 115:1907-1912. [PMID: 29432192 PMCID: PMC5828611 DOI: 10.1073/pnas.1717906115] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Cysteinyl-leukotrienes (cys-LTs) are lipid mediators involved in human inflammatory diseases, in particular asthma. We have previously identified cys-LTs in tissue specimens of human abdominal aortic aneurysm (AAA) and linked these mediators to increased metalloproteinase activity. Here we show in vivo that antagonism of the CysLT1 receptor by montelukast, an established antiasthma drug, protects against aneurysm in three mouse models of AAA at doses comparable to human medical practice. Together, these data support the role of cys-LTs in AAA and indicate a new potential therapeutic approach for treatment of this clinically silent and highly lethal disease. Cysteinyl-leukotrienes (cys-LTs) are 5-lipoxygenase-derived lipid mediators involved in the pathogenesis and progression of inflammatory disorders, in particular asthma. We have previously found evidence linking these mediators to increased levels of proteolytic enzymes in tissue specimens of human abdominal aortic aneurysm (AAA). Here we show that antagonism of the CysLT1 receptor by montelukast, an established antiasthma drug, protects against a strong aorta dilatation (>50% increase = aneurysm) in a mouse model of CaCl2-induced AAA at a dose comparable to human medical practice. Analysis of tissue extracts revealed that montelukast reduces the levels of matrix metalloproteinase-9 (MMP-9) and macrophage inflammatory protein-1α (MIP-1α) in the aortic wall. Furthermore, aneurysm progression was specifically mediated through CysLT1 signaling since a selective CysLT2 antagonist was without effect. A significantly reduced vessel dilatation is also observed when treatment with montelukast is started days after aneurysm induction, suggesting that the drug not only prevents but also stops and possibly reverts an already ongoing degenerative process. Moreover, montelukast reduced the incidence of aortic rupture and attenuated the AAA development in two additional independent models, i.e., angiotensin II- and porcine pancreatic elastase-induced AAA, respectively. Our results indicate that cys-LTs are involved in the pathogenesis of AAA and that antagonism of the CysLT1 receptor is a promising strategy for preventive and therapeutic treatment of this clinically silent and highly lethal disease.
Collapse
|
5
|
Wan M, Tang X, Stsiapanava A, Haeggström JZ. Biosynthesis of leukotriene B 4. Semin Immunol 2017; 33:3-15. [DOI: 10.1016/j.smim.2017.07.012] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 05/29/2017] [Accepted: 07/31/2017] [Indexed: 12/31/2022]
|
6
|
Abstract
Abdominal aortic aneurysm (AAA) is a significant cause of mortality in older adults. A key mechanism implicated in AAA pathogenesis is inflammation and the associated production of reactive oxygen species (ROS) and oxidative stress. These have been suggested to promote degradation of the extracellular matrix (ECM) and vascular smooth muscle apoptosis. Experimental and human association studies suggest that ROS can be favourably modified to limit AAA formation and progression. In the present review, we discuss mechanisms potentially linking ROS to AAA pathogenesis and highlight potential treatment strategies targeting ROS. Currently, none of these strategies has been shown to be effective in clinical practice.
Collapse
|
7
|
Kroon AM, Taanman JW. Clonal expansion of T cells in abdominal aortic aneurysm: a role for doxycycline as drug of choice? Int J Mol Sci 2015; 16:11178-95. [PMID: 25993290 PMCID: PMC4463695 DOI: 10.3390/ijms160511178] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 02/05/2015] [Indexed: 11/16/2022] Open
Abstract
Most reported studies with animal models of abdominal aortic aneurysm (AAA) and several studies with patients have suggested that doxycycline favourably modifies AAA; however, a recent large long-term clinical trial found that doxycycline did not limit aneurysm growth. Thus, there is currently no convincing evidence that doxycycline reduces AAA expansion. Here, we critically review the available experimental and clinical information about the effects of doxycycline when used as a pharmacological treatment for AAA. The view that AAA can be considered an autoimmune disease and the observation that AAA tissue shows clonal expansion of T cells is placed in the light of the well-known inhibition of mitochondrial protein synthesis by doxycycline. In T cell leukaemia animal models, this inhibitory effect of the antibiotic has been shown to impede T cell proliferation, resulting in complete tumour eradication. We suggest that the available evidence of doxycycline action on AAA is erroneously ascribed to its inhibition of matrix metalloproteinases (MMPs) by competitive binding of the zinc ion co-factor. Although competitive binding may explain the inhibition of proteolytic activity, it does not explain the observed decreases of MMP mRNA levels. We propose that the observed effects of doxycycline are secondary to inhibition of mitochondrial protein synthesis. Provided that serum doxycycline levels are kept at adequate levels, the inhibition will result in a proliferation arrest, especially of clonally expanding T cells. This, in turn, leads to the decrease of proinflammatory cytokines that are normally generated by these cells. The drastic change in cell type composition may explain the changes in MMP mRNA and protein levels in the tissue samples.
Collapse
Affiliation(s)
- Albert M Kroon
- Department of Clinical Neurosciences, Institute of Neurology, University College London, London NW3 2PF, UK.
| | - Jan-Willem Taanman
- Department of Clinical Neurosciences, Institute of Neurology, University College London, London NW3 2PF, UK.
| |
Collapse
|
8
|
Trachet B, Fraga-Silva RA, Piersigilli A, Tedgui A, Sordet-Dessimoz J, Astolfo A, Van der Donckt C, Modregger P, Stampanoni MFM, Segers P, Stergiopulos N. Dissecting abdominal aortic aneurysm in Ang II-infused mice: suprarenal branch ruptures and apparent luminal dilatation. Cardiovasc Res 2014; 105:213-22. [DOI: 10.1093/cvr/cvu257] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
|
9
|
Bhamidipati CM, Whatling CA, Mehta GS, Meher AK, Hajzus VA, Su G, Salmon M, Upchurch GR, Owens GK, Ailawadi G. 5-Lipoxygenase pathway in experimental abdominal aortic aneurysms. Arterioscler Thromb Vasc Biol 2014; 34:2669-78. [PMID: 25324573 PMCID: PMC4239157 DOI: 10.1161/atvbaha.114.304016] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
OBJECTIVE The impact of leukotriene production by the 5-lipoxygenase (5-LO) pathway in the pathophysiology of abdominal aortic aneurysms (AAAs) has been debated. Moreover, a clear mechanism through which 5-LO influences AAA remains unclear. APPROACH AND RESULTS Aneurysm formation was attenuated in 5-LO(-/-) mice, and in lethally irradiated wild-type mice reconstituted with 5-LO(-/-) bone marrow in an elastase perfusion model. Pharmacological inhibition of 5-LO-attenuated aneurysm formation in both aortic elastase perfused wild-type and angiotensin II-treated LDLr(-/-) (low-density lipoprotein receptor) mice, with resultant preservation of elastin and fewer 5-LO and MMP9 (matrix metalloproteinase)-producing cells. Separately, analysis of wild-type mice 7 days after elastase perfusion showed that 5-LO inhibition was associated with reduced polymorphonuclear leukocyte infiltration to the aortic wall. Importantly, 5-LO inhibition initiated 3 days after elastase perfusion in wild-type mice arrested progression of small AAA. Human AAA and control aorta corroborated these elastin and 5-LO expression patterns. CONCLUSIONS Inhibition of 5-LO by pharmacological or genetic approaches attenuates aneurysm formation and prevents fragmentation of the medial layer in 2 unique AAA models. Administration of 5-LO inhibitor in small AAA slows progression of AAA. Targeted interruption of the 5-LO pathway is a potential treatment strategy in AAA.
Collapse
MESH Headings
- Aged
- Angiotensin II/metabolism
- Animals
- Aorta, Abdominal/drug effects
- Aorta, Abdominal/enzymology
- Aorta, Abdominal/pathology
- Aortic Aneurysm, Abdominal/enzymology
- Aortic Aneurysm, Abdominal/etiology
- Aortic Aneurysm, Abdominal/pathology
- Arachidonate 5-Lipoxygenase/deficiency
- Arachidonate 5-Lipoxygenase/genetics
- Arachidonate 5-Lipoxygenase/metabolism
- Bone Marrow Transplantation
- Disease Models, Animal
- Disease Progression
- Humans
- Hypercholesterolemia/complications
- Hypercholesterolemia/enzymology
- Lipoxygenase Inhibitors/pharmacology
- Male
- Matrix Metalloproteinase 9/biosynthesis
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Middle Aged
- Neutrophil Infiltration
- Pancreatic Elastase/metabolism
- Receptors, LDL/deficiency
- Receptors, LDL/genetics
- Signal Transduction
- Transplantation Chimera/metabolism
Collapse
Affiliation(s)
- Castigliano M Bhamidipati
- From the Division of Thoracic and Cardiovascular Surgery, Department of Surgery (C.M.B., A.K.M., V.A.H., G.A.), Department of Surgery (G.S.M.), Division of Vascular and Endovascular Surgery, Department of Surgery (G.S., G.R.U.), Department of Molecular Physiology and Biological Physics (M.S., G.K.O.), Department of Molecular Physiology and Biological Physics, Robert M. Berne Cardiovascular Research Center (G.R.U., G.K.O., G.A.), and Department of Biomedical Engineering (G.A.), University of Virginia School of Medicine, Charlottesville; and Cardiovascular Disease Section, Bioscience Department, AstraZeneca R&D, Mölndal, Sweden (C.A.W.)
| | - Carl A Whatling
- From the Division of Thoracic and Cardiovascular Surgery, Department of Surgery (C.M.B., A.K.M., V.A.H., G.A.), Department of Surgery (G.S.M.), Division of Vascular and Endovascular Surgery, Department of Surgery (G.S., G.R.U.), Department of Molecular Physiology and Biological Physics (M.S., G.K.O.), Department of Molecular Physiology and Biological Physics, Robert M. Berne Cardiovascular Research Center (G.R.U., G.K.O., G.A.), and Department of Biomedical Engineering (G.A.), University of Virginia School of Medicine, Charlottesville; and Cardiovascular Disease Section, Bioscience Department, AstraZeneca R&D, Mölndal, Sweden (C.A.W.)
| | - Gaurav S Mehta
- From the Division of Thoracic and Cardiovascular Surgery, Department of Surgery (C.M.B., A.K.M., V.A.H., G.A.), Department of Surgery (G.S.M.), Division of Vascular and Endovascular Surgery, Department of Surgery (G.S., G.R.U.), Department of Molecular Physiology and Biological Physics (M.S., G.K.O.), Department of Molecular Physiology and Biological Physics, Robert M. Berne Cardiovascular Research Center (G.R.U., G.K.O., G.A.), and Department of Biomedical Engineering (G.A.), University of Virginia School of Medicine, Charlottesville; and Cardiovascular Disease Section, Bioscience Department, AstraZeneca R&D, Mölndal, Sweden (C.A.W.)
| | - Akshaya K Meher
- From the Division of Thoracic and Cardiovascular Surgery, Department of Surgery (C.M.B., A.K.M., V.A.H., G.A.), Department of Surgery (G.S.M.), Division of Vascular and Endovascular Surgery, Department of Surgery (G.S., G.R.U.), Department of Molecular Physiology and Biological Physics (M.S., G.K.O.), Department of Molecular Physiology and Biological Physics, Robert M. Berne Cardiovascular Research Center (G.R.U., G.K.O., G.A.), and Department of Biomedical Engineering (G.A.), University of Virginia School of Medicine, Charlottesville; and Cardiovascular Disease Section, Bioscience Department, AstraZeneca R&D, Mölndal, Sweden (C.A.W.)
| | - Vanessa A Hajzus
- From the Division of Thoracic and Cardiovascular Surgery, Department of Surgery (C.M.B., A.K.M., V.A.H., G.A.), Department of Surgery (G.S.M.), Division of Vascular and Endovascular Surgery, Department of Surgery (G.S., G.R.U.), Department of Molecular Physiology and Biological Physics (M.S., G.K.O.), Department of Molecular Physiology and Biological Physics, Robert M. Berne Cardiovascular Research Center (G.R.U., G.K.O., G.A.), and Department of Biomedical Engineering (G.A.), University of Virginia School of Medicine, Charlottesville; and Cardiovascular Disease Section, Bioscience Department, AstraZeneca R&D, Mölndal, Sweden (C.A.W.)
| | - Gang Su
- From the Division of Thoracic and Cardiovascular Surgery, Department of Surgery (C.M.B., A.K.M., V.A.H., G.A.), Department of Surgery (G.S.M.), Division of Vascular and Endovascular Surgery, Department of Surgery (G.S., G.R.U.), Department of Molecular Physiology and Biological Physics (M.S., G.K.O.), Department of Molecular Physiology and Biological Physics, Robert M. Berne Cardiovascular Research Center (G.R.U., G.K.O., G.A.), and Department of Biomedical Engineering (G.A.), University of Virginia School of Medicine, Charlottesville; and Cardiovascular Disease Section, Bioscience Department, AstraZeneca R&D, Mölndal, Sweden (C.A.W.)
| | - Morgan Salmon
- From the Division of Thoracic and Cardiovascular Surgery, Department of Surgery (C.M.B., A.K.M., V.A.H., G.A.), Department of Surgery (G.S.M.), Division of Vascular and Endovascular Surgery, Department of Surgery (G.S., G.R.U.), Department of Molecular Physiology and Biological Physics (M.S., G.K.O.), Department of Molecular Physiology and Biological Physics, Robert M. Berne Cardiovascular Research Center (G.R.U., G.K.O., G.A.), and Department of Biomedical Engineering (G.A.), University of Virginia School of Medicine, Charlottesville; and Cardiovascular Disease Section, Bioscience Department, AstraZeneca R&D, Mölndal, Sweden (C.A.W.)
| | - Gilbert R Upchurch
- From the Division of Thoracic and Cardiovascular Surgery, Department of Surgery (C.M.B., A.K.M., V.A.H., G.A.), Department of Surgery (G.S.M.), Division of Vascular and Endovascular Surgery, Department of Surgery (G.S., G.R.U.), Department of Molecular Physiology and Biological Physics (M.S., G.K.O.), Department of Molecular Physiology and Biological Physics, Robert M. Berne Cardiovascular Research Center (G.R.U., G.K.O., G.A.), and Department of Biomedical Engineering (G.A.), University of Virginia School of Medicine, Charlottesville; and Cardiovascular Disease Section, Bioscience Department, AstraZeneca R&D, Mölndal, Sweden (C.A.W.)
| | - Gary K Owens
- From the Division of Thoracic and Cardiovascular Surgery, Department of Surgery (C.M.B., A.K.M., V.A.H., G.A.), Department of Surgery (G.S.M.), Division of Vascular and Endovascular Surgery, Department of Surgery (G.S., G.R.U.), Department of Molecular Physiology and Biological Physics (M.S., G.K.O.), Department of Molecular Physiology and Biological Physics, Robert M. Berne Cardiovascular Research Center (G.R.U., G.K.O., G.A.), and Department of Biomedical Engineering (G.A.), University of Virginia School of Medicine, Charlottesville; and Cardiovascular Disease Section, Bioscience Department, AstraZeneca R&D, Mölndal, Sweden (C.A.W.)
| | - Gorav Ailawadi
- From the Division of Thoracic and Cardiovascular Surgery, Department of Surgery (C.M.B., A.K.M., V.A.H., G.A.), Department of Surgery (G.S.M.), Division of Vascular and Endovascular Surgery, Department of Surgery (G.S., G.R.U.), Department of Molecular Physiology and Biological Physics (M.S., G.K.O.), Department of Molecular Physiology and Biological Physics, Robert M. Berne Cardiovascular Research Center (G.R.U., G.K.O., G.A.), and Department of Biomedical Engineering (G.A.), University of Virginia School of Medicine, Charlottesville; and Cardiovascular Disease Section, Bioscience Department, AstraZeneca R&D, Mölndal, Sweden (C.A.W.).
| |
Collapse
|
10
|
Kuhn H, Banthiya S, van Leyen K. Mammalian lipoxygenases and their biological relevance. Biochim Biophys Acta Mol Cell Biol Lipids 2014; 1851:308-30. [PMID: 25316652 DOI: 10.1016/j.bbalip.2014.10.002] [Citation(s) in RCA: 419] [Impact Index Per Article: 41.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Revised: 09/30/2014] [Accepted: 10/03/2014] [Indexed: 02/07/2023]
Abstract
Lipoxygenases (LOXs) form a heterogeneous class of lipid peroxidizing enzymes, which have been implicated not only in cell proliferation and differentiation but also in the pathogenesis of various diseases with major public health relevance. As other fatty acid dioxygenases LOXs oxidize polyunsaturated fatty acids to their corresponding hydroperoxy derivatives, which are further transformed to bioactive lipid mediators (eicosanoids and related substances). On the other hand, lipoxygenases are key players in the regulation of the cellular redox homeostasis, which is an important element in gene expression regulation. Although the first mammalian lipoxygenases were discovered 40 years ago and although the enzymes have been well characterized with respect to their structural and functional properties the biological roles of the different lipoxygenase isoforms are not completely understood. This review is aimed at summarizing the current knowledge on the physiological roles of different mammalian LOX-isoforms and their patho-physiological function in inflammatory, metabolic, hyperproliferative, neurodegenerative and infectious disorders. This article is part of a Special Issue entitled "Oxygenated metabolism of PUFA: analysis and biological relevance".
Collapse
Affiliation(s)
- Hartmut Kuhn
- Institute of Biochemistry, University Medicine Berlin - Charite, Chariteplatz 1, CCO-Building, Virchowweg 6, D-10117 Berlin, Germany.
| | - Swathi Banthiya
- Institute of Biochemistry, University Medicine Berlin - Charite, Chariteplatz 1, CCO-Building, Virchowweg 6, D-10117 Berlin, Germany
| | - Klaus van Leyen
- Neuroprotection Research Laboratory, Department of Radiology, Massachusetts Genrel Hospital and Harvard Medical School, Charlestown, MA, USA
| |
Collapse
|
11
|
Di Gennaro A, Haeggström JZ. Targeting leukotriene B4 in inflammation. Expert Opin Ther Targets 2013; 18:79-93. [PMID: 24090264 DOI: 10.1517/14728222.2013.843671] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
INTRODUCTION Leukotriene (LT) B(4) is a powerful proinflammatory lipid mediator and triggers adherence to the endothelium, activates and recruits leukocytes to the site of injury. When formed in excess, LTB(4) plays a pathogenic role and may sustain chronic inflammation in diseases such as asthma, rheumatoid arthritis, and inflammatory bowel disease. Recent investigations have also indicated that LTB(4) is involved in cardiovascular diseases. AREAS COVERED As the 5-lipoxygenase pathway involves several discrete, tightly coupled, enzymes, which convert the substrate, 'step by step', into bioactive products, several different strategies have been used to target LTB(4) as a means to treat inflammation. Here, we discuss recent findings regarding the development of selective enzyme inhibitors and antagonists for LTB(4) receptors, as well as their application in preclinical and clinical studies. EXPERT OPINION Components of the 5-lipoxygenase pathway have received considerable attention as candidate drug targets resulting in one new class of medications against asthma, that is, the antileukotrienes. However, efforts to specifically target LTB(4) have not yet been fruitful in the clinical setting, in spite of very promising preclinical data. Recently, crystal structures along with hitherto unknown functions of key enzymes in the leukotriene cascade have emerged, offering new opportunities for drug development and, with time, pharmacological intervention in LTB(4)-mediated pathologies.
Collapse
Affiliation(s)
- Antonio Di Gennaro
- Karolinska Institutet, Department of Medical Biochemistry and Biophysics, Division of Chemistry 2 , Scheeles väg 2, Stockholm, S-171 77 , Sweden
| | | |
Collapse
|
12
|
Effectiveness of cyclooxygenase-2 inhibition in limiting abdominal aortic aneurysm progression in mice correlates with a differentiated smooth muscle cell phenotype. J Cardiovasc Pharmacol 2013; 60:520-9. [PMID: 22967986 DOI: 10.1097/fjc.0b013e318270b968] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Abdominal aortic aneurysms (AAAs) are a chronic condition that often progress over years to produce a weakened aorta with increased susceptibility for rupture, and currently, there are no pharmacological treatments available to slow disease progression. AAA development has been characterized by increased expression of cyclooxygenase-2 (COX-2), and inactivation of COX-2 before disease initiation reduces AAA incidence in a mouse model of the disease. The current study determined the effectiveness of COX-2 inhibition on AAA progression when treatment was begun after initiation of the disease. COX-2 inhibitor treatment with celecoxib was initiated after angiotensin II-induced AAA formation in a strain of nonhyperlipidemic mice that we have previously identified as highly susceptible to AAA development. When analyzed at different time points during progression of the disease, celecoxib treatment significantly reduced the incidence and severity of AAAs. The celecoxib treatment also protected the mice from aortic rupture and death. The aneurysmal lesion displayed an altered smooth muscle cell (SMC) phenotype, whereas celecoxib treatment was associated with increased expression of differentiated SMC markers and reduced dedifferentiation marker expression during AAA progression. Maintenance of a differentiated SMC phenotype is associated with the effectiveness of COX-2 inhibition for limiting AAA progression in nonhyperlipidemic mice.
Collapse
|
13
|
Di Gennaro A, Haeggström JZ. The leukotrienes: immune-modulating lipid mediators of disease. Adv Immunol 2013; 116:51-92. [PMID: 23063073 DOI: 10.1016/b978-0-12-394300-2.00002-8] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The leukotrienes are important lipid mediators with immune modulatory and proinflammatory properties. Classical bioactions of leukotrienes include chemotaxis, endothelial adherence, and activation of leukocytes, chemokine production, as well as contraction of smooth muscles in the microcirculation and respiratory tract. When formed in excess, these compounds play a pathogenic role in several acute and chronic inflammatory diseases, such as asthma, rheumatoid arthritis, and inflammatory bowel disease. An increasing number of diseases have been linked to inflammation implicating the leukotrienes as potential mediators. For example, recent investigations using genetic, morphological, and biochemical approaches have pointed to the involvement of leukotrienes in cardiovascular diseases including atherosclerosis, myocardial infarction, stroke, and abdominal aortic aneurysm. Moreover, new insights have changed our previous notion of leukotrienes as mediators of inflammatory reactions to molecules that can fine-tune the innate and adaptive immune response. Here, we review the most recent understanding of the leukotriene cascade with emphasis on recently identified roles in immune reactions and pathophysiology.
Collapse
Affiliation(s)
- Antonio Di Gennaro
- Department of Medical Biochemistry and Biophysics, Division of Chemistry 2, Karolinska Institutet, Stockholm, Sweden
| | | |
Collapse
|
14
|
Involvement of the renin-angiotensin system in abdominal and thoracic aortic aneurysms. Clin Sci (Lond) 2012; 123:531-43. [PMID: 22788237 DOI: 10.1042/cs20120097] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Aortic aneurysms are relatively common maladies that may lead to the devastating consequence of aortic rupture. AAAs (abdominal aortic aneurysms) and TAAs (thoracic aortic aneurysms) are two common forms of aneurysmal diseases in humans that appear to have distinct pathologies and mechanisms. Despite this divergence, there are numerous and consistent demonstrations that overactivation of the RAS (renin-angiotensin system) promotes both AAAs and TAAs in animal models. For example, in mice, both AAAs and TAAs are formed during infusion of AngII (angiotensin II), the major bioactive peptide in the RAS. There are many proposed mechanisms by which the RAS initiates and perpetuates aortic aneurysms, including effects of AngII on a diverse array of cell types and mediators. These experimental findings are complemented in humans by genetic association studies and retrospective analyses of clinical data that generally support a role of the RAS in both AAAs and TAAs. Given the lack of a validated pharmacological therapy for any form of aortic aneurysm, there is a pressing need to determine whether the consistent findings on the role of the RAS in animal models are translatable to humans afflicted with these diseases. The present review compiles the recent literature that has shown the RAS as a critical component in the pathogenesis of aortic aneurysms.
Collapse
|
15
|
Capra V, Bäck M, Barbieri SS, Camera M, Tremoli E, Rovati GE. Eicosanoids and Their Drugs in Cardiovascular Diseases: Focus on Atherosclerosis and Stroke. Med Res Rev 2012; 33:364-438. [DOI: 10.1002/med.21251] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Valérie Capra
- Department of Pharmacological Sciences; University of Milan; Via Balzaretti 9 20133 Milan Italy
| | - Magnus Bäck
- Department of Cardiology and Center for Molecular Medicine; Karolinska University Hospital; Stockholm Sweden
| | | | - Marina Camera
- Department of Pharmacological Sciences; University of Milan; Via Balzaretti 9 20133 Milan Italy
- Centro Cardiologico Monzino; I.R.C.C.S Milan Italy
| | - Elena Tremoli
- Department of Pharmacological Sciences; University of Milan; Via Balzaretti 9 20133 Milan Italy
- Centro Cardiologico Monzino; I.R.C.C.S Milan Italy
| | - G. Enrico Rovati
- Department of Pharmacological Sciences; University of Milan; Via Balzaretti 9 20133 Milan Italy
| |
Collapse
|
16
|
Revermann M, Mieth A, Popescu L, Paulke A, Wurglics M, Pellowska M, Fischer AS, Steri R, Maier TJ, Schermuly RT, Geisslinger G, Schubert-Zsilavecz M, Brandes RP, Steinhilber D. A pirinixic acid derivative (LP105) inhibits murine 5-lipoxygenase activity and attenuates vascular remodelling in a murine model of aortic aneurysm. Br J Pharmacol 2012; 163:1721-32. [PMID: 21410457 DOI: 10.1111/j.1476-5381.2011.01321.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND AND PURPOSE Arachidonic acid derivatives play a central role in inflammation processes. Arachidonic acid is metabolized by several enzymes, particularly cyclooxygenases (COX), 5-lipoxygenase (5-LOX) and microsomal prostaglandin E-synthase-1 (mPGES-1) to pro-inflammatory mediators. EXPERIMENTAL APPROACH We determined the effect of LP105, a pirinixic acid derivative which acts as inhibitor of 5-LOX, COX and mPGES-1, on aortic aneurysm development in mice and on 5-LOX activity in murine monocytes. KEY RESULTS In a monocyte cell line (RAW264.7), LP105 inhibited 5-LOX in whole cells (IC(50) : 1-3 µM) and in supernatants (IC(50) : ∼10 µM). Oral administration of LP105 to mice resulted in therapeutic tissue and plasma levels. Aortic aneurysms were induced in ApoE(-/-) mice by angiotensin II (AngII) and LP105 (5 mg·day(-1) per animal) was co-administered to a subgroup. Compared with animals receiving AngII alone, the LP105+AngII group showed a lower heart rate, a trend towards reduced heart to body weight ratio but similar hypertensive responses. AngII alone significantly increased aortic weight and diameter but co-treatment with LP105+AngII prevented these changes. LC/MS-MS studies revealed increased 15-hydroxytetraenoic acid (15-HETE) and 14,15-epoxyeicosatrienoic acid (14,15-EET) plasma levels in LP105-treated animals. In the murine kidney, mRNAs of EET-generating or metabolizing enzymes and of 5-LOX and 15-LOX were unaffected by LP105. LP105 also did not inhibit the EET-metabolizing soluble epoxide hydrolase. CONCLUSIONS AND IMPLICATIONS LP105 was a potent inhibitor of monocyte 5-LOX and reduced AngII-induced vascular remodelling in mice. A shift of arachidonic acid metabolism to the protective EET pathway may contribute to the beneficial effects of LP105.
Collapse
Affiliation(s)
- M Revermann
- Institut für Kardiovaskuläre Physiologie, Fachbereich Medizin, Goethe-Universität Frankfurt, Theodor-Stern-Kai 7, Frankfurt am Main, Germany
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Haeggström JZ, Funk CD. Lipoxygenase and leukotriene pathways: biochemistry, biology, and roles in disease. Chem Rev 2011; 111:5866-98. [PMID: 21936577 DOI: 10.1021/cr200246d] [Citation(s) in RCA: 609] [Impact Index Per Article: 46.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Jesper Z Haeggström
- Department of Medical Biochemistry and Biophysics, Division of Chemistry 2, Karolinska Institutet, S-171 77 Stockholm, Sweden.
| | | |
Collapse
|
18
|
Bäck M, Dahlén SE, Drazen JM, Evans JF, Serhan CN, Shimizu T, Yokomizo T, Rovati GE. International Union of Basic and Clinical Pharmacology. LXXXIV: Leukotriene Receptor Nomenclature, Distribution, and Pathophysiological Functions. Pharmacol Rev 2011; 63:539-84. [DOI: 10.1124/pr.110.004184] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
|
19
|
Affiliation(s)
- Motonao Nakamura
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, The University of Tokyo, Hongo, Tokyo, Japan.
| | | |
Collapse
|
20
|
Li RC, Haribabu B, Mathis SP, Kim J, Gozal D. Leukotriene B4 receptor-1 mediates intermittent hypoxia-induced atherogenesis. Am J Respir Crit Care Med 2011; 184:124-31. [PMID: 21493735 DOI: 10.1164/rccm.201012-2039oc] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
RATIONALE Obstructive sleep apnea, which is characterized by intermittent hypoxia (IH) during sleep, has emerged as an independent risk factor for cardiovascular disease, including atherosclerosis. Leukotriene B4 (LTB4) production is increased in patients with obstructive sleep apnea and negatively correlates to hypoxic levels during sleep, with continuous positive airway pressure therapy decreasing LTB4 production. OBJECTIVES Determine the potential role of LTB4 in IH-induced atherosclerosis in a monocyte cellular model and a murine model. METHODS THP-1 cells were exposed to IH for 3, 6, 24, and 48 hours. Macrophage transformation and foam cell formation were assessed after IH exposures. Apolipopotein E (ApoE)(-/-) or BLT1(-/-)/ApoE(-/-) mice were fed an atherogenic diet and exposed to IH (alternating 21% and 5.7% O(2) from 7 am to 7 PM each day) for 10 weeks. Atherosclerotic lesion formation in en face aorta was examined by oil red O staining. MEASUREMENTS AND MAIN RESULTS IH increased production of LTB4 and the expression of 5-lipoxygenase and leukotriene A4 hydrolase, the key enzymes for producing LTB4. IH was associated with transformation of monocytes to activated macrophages, as evidenced by increased expression of CD14 and CD68. In addition, IH exposures promoted increased cellular cholesterol accumulation and foam cell formation. The LTB4 receptor 1 (BLT1) antagonist U-75302 markedly attenuated IH-induced changes. Furthermore, IH promoted atherosclerotic lesion formation in ApoE(-/-) mice. IH-induced lesion formation was markedly attenuated in BLT1(-/-)/ApoE(-/-) mice. CONCLUSIONS BLT1-dependent pathways underlie IH-induced atherogenesis, and may become a potential novel therapeutic target for obstructive sleep apnea-associated cardiovascular disease.
Collapse
Affiliation(s)
- Richard C Li
- Department of Pediatrics, The University of Chicago, Chicago, IL 60637, USA.
| | | | | | | | | |
Collapse
|
21
|
Increased expression of leukotriene C4 synthase and predominant formation of cysteinyl-leukotrienes in human abdominal aortic aneurysm. Proc Natl Acad Sci U S A 2010; 107:21093-7. [PMID: 21078989 DOI: 10.1073/pnas.1015166107] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Leukotrienes (LTs) are arachidonic acid-derived lipid mediators involved in the pathogenesis and progression of diverse inflammatory disorders. The cysteinyl-leukotrienes LTC(4), LTD(4), and LTE(4) are important mediators of asthma, and LTB(4) has recently been implicated in atherosclerosis. Here we report that mRNA levels for the three key enzymes/proteins in the biosynthesis of cysteinyl-leukotrienes, 5-lipoxygenase (5-LO), 5-LO-activating protein (FLAP), and LTC(4) synthase (LTC(4)S), are significantly increased in the wall of human abdominal aortic aneurysms (AAAs). In contrast, mRNA levels of LTA(4) hydrolase, the enzyme responsible for the biosynthesis of LTB(4), are not increased. Immunohistochemical staining of AAA wall revealed focal expression of 5-LO, FLAP, and LTC(4)S proteins in the media and adventitia, localized in areas rich in inflammatory cells, including macrophages, neutrophils, and mast cells. Human AAA wall tissue converts arachidonic acid and the unstable epoxide LTA(4) into significant amounts of cysteinyl-leukotrienes and to a lesser extent LTB(4). Furthermore, challenge of AAA wall tissue with exogenous LTD(4) increases the release of matrix metalloproteinase (MMP) 2 and 9, and selective inhibition of the CysLT1 receptor by montelukast blocks this effect. The increased expression of LTC(4)S, together with the predominant formation of cysteinyl-leukotrienes and effects on MMPs production, suggests a mechanism by which LTs may promote matrix degradation in the AAA wall and identify the components of the cysteinyl-leukotriene pathway as potential targets for prevention and treatment of AAA.
Collapse
|
22
|
Angiotensin II infusion promotes ascending aortic aneurysms: attenuation by CCR2 deficiency in apoE-/- mice. Clin Sci (Lond) 2010; 118:681-9. [PMID: 20088827 PMCID: PMC2841499 DOI: 10.1042/cs20090372] [Citation(s) in RCA: 142] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
AngII (angiotensin II) induces atherosclerosis and AAAs (abdominal aortic aneurysms) through multiple proposed mechanisms, including chemotaxis. Therefore, we determined the effects of whole-body deficiency of the chemokine receptor CCR2 (CC chemokine receptor 2) on these diseases. To meet this objective, apoE (apolipoprotein E)−/− mice that were either CCR2+/+ or CCR2−/−, were infused with either saline or AngII (1000 ng·kg−1 of body weight·min−1) for 28 days via mini-osmotic pumps. Deficiency of CCR2 markedly attenuated both atherosclerosis and AAAs, unrelated to systolic blood pressure or plasma cholesterol concentrations. During the course of the present study, we also observed that AngII infusion led to large dilatations that were restricted to the ascending aortic region of apoE−/− mice. The aortic media in most of the dilated area was thickened. In regions of medial thickening, distinct elastin layers were discernable. There was an expansion of the distance between elastin layers in a gradient from the intimal to the adventitial aspect of the media. This pathology differed in a circumscribed area of the anterior region of ascending aortas in which elastin breaks were focal and almost transmural. All regions of the ascending aorta of AngII-infused mice had diffuse medial macrophage accumulation. Deficiency of CCR2 greatly attenuated the AngII-induced lumen dilatation in the ascending aorta. This new model of ascending aortic aneurysms has pathology that differs markedly from AngII-induced atherosclerosis or AAAs, but all vascular pathologies were attenuated by CCR2 deficiency.
Collapse
|