Nicotine Exacerbates TAAD Formation Induced by Smooth Muscle-Specific Deletion of the TGF-β Receptor 2

Copyright © 2021 Changzoon Chun et al..

Tobacco smoke is an established risk factor for thoracic aortic aneurysms and dissections (TAAD). However, little is known about its underlying mechanisms due to the lack of validated animal models. The present study developed a mouse model that may be utilized to investigate exacerbation of TAAD formation by mimetics of tobacco smoke. TAADs were created via inducible deletion of smooth muscle cell-specific Tgfbr2 receptors. Using this model, the first set of experiments evaluated the efficacy of nicotine salt (34.0 mg/kg/day), nicotine free base (NFB, 5.0 mg 90-day pellets), and cigarette smoke extract (0.1 ml/mouse/day). Compared with their respective control groups, only NFB pellets promoted TAAD dilation (23 ± 3% vs. 12 ± 2%, P = 0.014), and this efficacy was achieved at a cost of >50% acute mortality. Infusion of NFB with osmotic minipumps at extremely high, but nonlethal, doses (15.0 or 45.0 mg/kg/day) failed to accelerate TAAD dilation. Interestingly, costimulation with β-aminopropionitrile (BAPN) promoted TAAD dilation and aortic rupture at dosages of 3.0 and 45.0 mg/kg/day, respectively, indicating that BAPN sensitizes the response of TAADs to NFB. In subsequent analyses, the detrimental effects of NFB were associated with clustering of macrophages, neutrophils, and T-cells in areas with structural destruction, enhanced matrix metalloproteinase- (MMP-) 2 production, and pathological angiogenesis with attenuated fibrosis in the adventitia. In conclusion, modeling nicotine exacerbation of TAAD formation requires optimization of chemical form, route of delivery, and dosage of the drug as well as the pathologic complexity of TAADs. Under the optimized conditions of the present study, chronic inflammation and adventitial mal-remodeling serve as critical pathways through which NFB exacerbates TAAD formation.

Medienart:

E-Artikel

Erscheinungsjahr:

2021

Erschienen:

2021

Enthalten in:

Zur Gesamtaufnahme - volume:2021

Enthalten in:

Journal of immunology research - 2021(2021) vom: 11., Seite 6880036

Sprache:

Englisch

Beteiligte Personen:

Chun, Changzoon [VerfasserIn]
Qi, Xiaoyan [VerfasserIn]
Wang, Fen [VerfasserIn]
Madrid, Kyle B [VerfasserIn]
Saldarriaga, Lennon A [VerfasserIn]
Fisch, Max R [VerfasserIn]
Brantly, Mark L [VerfasserIn]
Upchurch, Gilbert R [VerfasserIn]
Jiang, Zhihua [VerfasserIn]

Links:

Volltext

Themen:

6M3C89ZY6R
EC 2.7.11.30
Journal Article
Nicotine
Receptor, Transforming Growth Factor-beta Type II
Tgfbr2 protein, mouse

Anmerkungen:

Date Completed 07.02.2022

Date Revised 07.12.2022

published: Electronic-eCollection

Citation Status MEDLINE

doi:

10.1155/2021/6880036

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM331876361