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Baratchi S, Zaldivia MTK, Wallert M, Loseff-Silver J, Al-Aryahi S, Zamani J, Thurgood P, Salim A, Htun NM, Stub D, Vahidi P, Duffy SJ, Walton A, Nguyen TH, Jaworowski A, Khoshmanesh K, Peter K. Transcatheter Aortic Valve Implantation Represents an Anti-Inflammatory Therapy Via Reduction of Shear Stress-Induced, Piezo-1-Mediated Monocyte Activation. Circulation 2020; 142:1092-1105. [PMID: 32697107 DOI: 10.1161/circulationaha.120.045536] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND Aortic valve stenosis is an increasingly prevalent degenerative and inflammatory disease. Transcatheter aortic valve implantation (TAVI) has revolutionized its treatment, thereby avoiding its life-threatening/disabling consequences. Whether aortic valve stenosis is accelerated by inflammation and whether it is itself a cause of inflammation are unclear. We hypothesized that the large shear forces exerted on circulating cells, particularly on the largest circulating cells, monocytes, while passing through stenotic aortic valves result in proinflammatory effects that are resolved with TAVI. METHODS TAVI provides a unique opportunity to compare the activation status of monocytes under high shear stress (before TAVI) and under low shear stress (after TAVI). The activation status of monocytes was determined with a single-chain antibody, MAN-1, which is specific for the activated β2-integrin Mac-1. Monocyte function was further characterized by the adhesion of myocytes to stimulated endothelial cells, phagocytic activity, uptake of oxidized low-density lipoprotein, and cytokine expression. In addition, we designed a microfluidic system to recapitulate the shear rate conditions before and after TAVI. We used this tool in combination with functional assays, Ca2+ imaging, siRNA gene silencing, and pharmacological agonists and antagonists to identify the key mechanoreceptor mediating the shear stress sensitivity of monocytes. Last, we stained for monocytes in explanted stenotic aortic human valves. RESULTS The resolution of high shear stress through TAVI reduces Mac-1 activation, cellular adhesion, phagocytosis, oxidized low-density lipoprotein uptake, and expression of inflammatory markers in monocytes and plasma. Using microfluidics and pharmacological and genetic studies, we could recapitulate high shear stress effects on isolated human monocytes under highly controlled conditions, showing that shear stress-dependent calcium influx and monocyte adhesion are mediated by the mechanosensitive ion channel Piezo-1. We also demonstrate that the expression of this receptor is shear stress dependent and downregulated in patients receiving TAVI. Last, we show monocyte accumulation at the aortic side of leaflets of explanted aortic valves. CONCLUSIONS We demonstrate that high shear stress, as present in patients with aortic valve stenosis, activates multiple monocyte functions, and we identify Piezo-1 as the mainly responsible mechanoreceptor, representing a potentially druggable target. We demonstrate an anti-inflammatory effect and therefore a novel therapeutic benefit of TAVI.
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Affiliation(s)
- Sara Baratchi
- School of Health and Biomedical Sciences (S.B., S.A.-A., P.V., A.J., K.P.), RMIT University, Melbourne, Victoria, Australia
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia (S.B., M.T.K.J., M.W., J.L.-S., A.S., N.M.H., D.S., K.P.)
| | - Maria T K Zaldivia
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia (S.B., M.T.K.J., M.W., J.L.-S., A.S., N.M.H., D.S., K.P.)
| | - Maria Wallert
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia (S.B., M.T.K.J., M.W., J.L.-S., A.S., N.M.H., D.S., K.P.)
| | - Julia Loseff-Silver
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia (S.B., M.T.K.J., M.W., J.L.-S., A.S., N.M.H., D.S., K.P.)
| | - Sefaa Al-Aryahi
- School of Health and Biomedical Sciences (S.B., S.A.-A., P.V., A.J., K.P.), RMIT University, Melbourne, Victoria, Australia
| | - Jalal Zamani
- Department of Cardiology, Alfred Hospital, Melbourne, Victoria, Australia (J.Z., N.M.H., D.S., S.J.D., A.W., K.P.)
| | - Peter Thurgood
- School of Engineering (P.T., K.K.), RMIT University, Melbourne, Victoria, Australia
| | - Agus Salim
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia (S.B., M.T.K.J., M.W., J.L.-S., A.S., N.M.H., D.S., K.P.)
- Department of Mathematics and Statistics, La Trobe University, Melbourne, Victoria, Australia (A.S.)
| | - Nay M Htun
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia (S.B., M.T.K.J., M.W., J.L.-S., A.S., N.M.H., D.S., K.P.)
- Department of Cardiology, Alfred Hospital, Melbourne, Victoria, Australia (J.Z., N.M.H., D.S., S.J.D., A.W., K.P.)
| | - Dion Stub
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia (S.B., M.T.K.J., M.W., J.L.-S., A.S., N.M.H., D.S., K.P.)
- Department of Cardiology, Alfred Hospital, Melbourne, Victoria, Australia (J.Z., N.M.H., D.S., S.J.D., A.W., K.P.)
- Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Victoria, Australia (D.S.)
| | - Parisa Vahidi
- School of Health and Biomedical Sciences (S.B., S.A.-A., P.V., A.J., K.P.), RMIT University, Melbourne, Victoria, Australia
| | - Stephen J Duffy
- Department of Cardiology, Alfred Hospital, Melbourne, Victoria, Australia (J.Z., N.M.H., D.S., S.J.D., A.W., K.P.)
| | - Antony Walton
- Department of Cardiology, Alfred Hospital, Melbourne, Victoria, Australia (J.Z., N.M.H., D.S., S.J.D., A.W., K.P.)
| | - Thanh Ha Nguyen
- Cardiology Department, Queen Elizabeth Hospital, University of Adelaide, Woodville, South Australia, Australia (T.H.N.)
| | - Anthony Jaworowski
- School of Health and Biomedical Sciences (S.B., S.A.-A., P.V., A.J., K.P.), RMIT University, Melbourne, Victoria, Australia
| | | | - Karlheinz Peter
- School of Health and Biomedical Sciences (S.B., S.A.-A., P.V., A.J., K.P.), RMIT University, Melbourne, Victoria, Australia
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia (S.B., M.T.K.J., M.W., J.L.-S., A.S., N.M.H., D.S., K.P.)
- Department of Cardiology, Alfred Hospital, Melbourne, Victoria, Australia (J.Z., N.M.H., D.S., S.J.D., A.W., K.P.)
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Varshney R, Murphy B, Woolington S, Ghafoory S, Chen S, Robison T, Ahamed J. Inactivation of platelet-derived TGF-β1 attenuates aortic stenosis progression in a robust murine model. Blood Adv 2019; 3:777-788. [PMID: 30846427 PMCID: PMC6418501 DOI: 10.1182/bloodadvances.2018025817] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 01/24/2019] [Indexed: 11/20/2022] Open
Abstract
Aortic stenosis (AS) is a degenerative heart condition characterized by fibrosis and narrowing of aortic valves (AV), resulting in high wall shear stress (WSS) across valves. AS is associated with high plasma levels of transforming growth factor-β1 (TGF-β1), which can be activated by WSS to induce organ fibrosis, but the cellular source of TGF-β1 is not clear. Here, we show that platelet-derived TGF-β1 plays an important role in AS progression. We first established an aggressive and robust murine model of AS, using the existing Ldlr -/- Apob100/100 (LDLR) breed of mice, and accelerated AS progression by feeding them a high-fat diet (HFD). We then captured very high resolution images of AV movement and thickness and of blood flow velocity across the AV, using a modified ultrasound imaging technique, which revealed early evidence of AS and distinguished different stages of AS progression. More than 90% of LDLR animals developed AS within 6 months of HFD. Scanning electron microscopy and whole-mount immunostaining imaging of AV identified activated platelets physically attached to valvular endothelial cells (VEC) expressing high phosphorylated Smad2 (p-Smad2). To test the contribution of platelet-derived TGF-β1 in AS, we derived LDLR mice lacking platelet TGF-β1 (TGF-β1platelet-KO-LDLR) and showed reduced AS progression and lower p-Smad2 and myofibroblasts in their AV compared with littermate controls fed the HFD for 6 months. Our data suggest that platelet-derived TGF-β1 triggers AS progression by inducing signaling in VEC, and their subsequent transformation into collagen-producing-myofibroblasts. Thus, inhibiting platelet-derived TGF-β1 might attenuate or prevent fibrotic diseases characterized by platelet activation and high WSS, such as AS.
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Affiliation(s)
- Rohan Varshney
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK; and
| | - Brennah Murphy
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK; and
| | - Sean Woolington
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK; and
| | - Shahrouz Ghafoory
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK; and
| | - Sixia Chen
- Department of Biostatistics and Epidemiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK
| | - Tyler Robison
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK; and
| | - Jasimuddin Ahamed
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK; and
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