Abstract
BACKGROUND: Smooth muscle cells (SMCs) regulate blood flow distribution via vasoconstriction mediated by α-ARs (α-adrenergic receptors). Plasma membrane cholesterol accumulation affects α 1-AR signaling and promotes loss of SMC contractile markers in vitro. ABCA1 and ABCG1 (ATP-binding cassette transporter A1 and G1) mediate cholesterol efflux to HDL (high-density lipoprotein). ABCA1/ABCG1 show high expression in medial and low expression in intimal SMCs of atherosclerotic plaques. The role of ABCA1 and ABCG1 in SMC-mediated vasoconstriction and atherogenesis remains poorly understood.
METHODS: We generated mice with SMC-specific Abca1/Abcg1 deficiency on the low-density lipoprotein receptor-deficient ( Ldlr - / - ) background by crossbreeding Abca1 fl/fl Abcg1 fl/fl Ldlr -/- mice with Myh11Cre ERT2 transgenic mice. To induce SMC cholesterol accumulation and atherogenesis, we fed Myh11Cre ERT2 Abca1 fl/fl Abcg1 fl/fl Ldlr -/- , Myh11Cre ERT2 Abca1 fl/fl Ldlr -/- , Myh11Cre ERT2 Abcg1 fl/fl Ldlr -/- , and Myh11Cre ERT2 Ldlr -/- mice Western-type diet for 16 weeks.
RESULTS: Combined SMC-Abca1/Abcg1 deficiency increased vasoconstriction in aortic rings induced by the α 1-AR agonist phenylephrine. Unexpectedly, SMC- Abca1/Abcg1 deficiency induced urinary bladder distension by >20-fold. This was reversed by the α 1-AR antagonist tamsulosin, indicating its dependence on bladder neck SMC constriction. Moreover, SMC- Abca1/Abcg1 deficiency decreased contractile markers and increased macrophage and fibroblast markers in bladder SMCs, indicating SMC transdifferentiation. This was accompanied by free cholesterol accumulation and increased endoplasmic reticulum stress. SMC- Abca1/Abcg1 deficiency did not induce thoracic aorta SMC transdifferentiation, presumably due to increased cholesteryl ester accumulation and no endoplasmic reticulum stress in thoracic aorta SMCs. Surprisingly, SMC- Abca1/Abcg1 deficiency did not affect atherosclerotic lesion size or composition in the aortic root or brachiocephalic artery.
CONCLUSIONS: We uncover a new role of SMC cholesterol efflux pathways in suppressing α 1-AR-mediated vasoconstriction and bladder SMC transdifferentiation, decreasing urinary bladder distension. Our data may provide a mechanistic link for the association between urinary bladder distension and diabetes in humans, particularly because diabetes is associated with decreased cholesterol efflux. SMC- Abca1/Abcg1 deficiency did not affect atherosclerotic lesion size or plaque composition, presumably due to low expression of Abca1/Abcg1 in intimal SMCs.
Original language | English |
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Pages (from-to) | 491-507 |
Number of pages | 17 |
Journal | Circulation Research |
Volume | 136 |
Issue number | 5 |
Early online date | 11 Feb 2025 |
DOIs | |
Publication status | Published - 28 Feb 2025 |
Bibliographical note
Publisher Copyright:© 2025 The Authors.
Funding
This work was supported by Marie Sk\u0142odowska-Curie grant 945478 from European Union (EU) Horizon 2020, the Slovak Academic and Scientific Programme grant 3333/03/02, and the Slovak Research and Development Agency grant PP-MSCA-2022-0001 (support for projects Marie Sk\u0142odowska-Curie Actions-2022-0001) (to D. Nakl\u00E1dal); VIDI grant 917.15.350 and an Aspasia grant from the Netherlands Organization of Scientific Research and a Rosalind Franklin Fellowship with an EU Co-Fund attached from the University of Groningen (to M. Westerterp); and the British Heart Foundation \u2014 German Centre for Cardiovascular Research \u2014Dutch Heart Foundation International Cardiovascular Research Partnership Award 02-001-2022-0125 (acronym PLAK TALK) to H.F. J\u00F8rgensen and M. Westerterp.
Funders | Funder number |
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Deutsches Zentrum für Herz-Kreislaufforschung | |
Nederlandse Organisatie voor Wetenschappelijk Onderzoek | |
Rijksuniversiteit Groningen | |
British Heart Foundation | |
European Commission | 3333/03/02 |
Agentúra na Podporu Výskumu a Vývoja | PP-MSCA-2022-0001 |
Dutch Heart Foundation International Cardiovascular Research | 02-001-2022-0125 |
H2020 Marie Skłodowska-Curie Actions | 945478 |
Marie Skłodowska-Curie Actions-2022-0001 | 917.15.350 |
Keywords
- atherosclerosis
- cell transdifferentiation
- cholesterol
- myocytes, smooth muscle
- vasoconstriction