Open AccessThe role of air pollution in myocardial remodeling
Author(s) -
Adriana M Oliveira-Fonoff,
Charles Mady,
Fernanda Gallinaro Pessoa,
Keila Cardoso Barbosa Fonseca,
V. M. C. Salemi,
Fábio Fernandes,
Paulo Hilário Nascimento Saldiva,
Felix José Alvarez Ramires
Publication year - 2017
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0176084
Subject(s) - ventricular remodeling , air pollution , cardiology , medicine , biology , myocardial infarction , ecology
Background Excessive air pollution in urban environments can impact morbidity and mortality. The authors evaluated the role of particulate matter 2.5 (PM 2.5 ) in structural, geometric, and functional remodeling in hearts, using an experimental model of myocardial infarction. Methods and findings Seventy-five rats were divided into 5 groups: control (CG), CG exposed to PM 2.5 pollution (CGP), myocardial infarcted group (MI), infarcted group immediately exposed to pollution (IGP-I), and infarcted group previously exposed to pollution and kept exposed after infarction (IGP-II). Greater deposition of interstitial collagen occurred in the left ventricle in CGP, MI, IGP-I, and IGP-II groups compared with that in controls (p = 0.002 CG vs CGP and p<0.0001 CG vs MI, IGP-I, and IGP-II). In the right ventricle, greater collagen deposition existed in CGP, MI, IGP-I, and IGP-II compared with that in CG (p<0.021 CG vs CGP and p<0.0001 CG vs MI, IGP-I, and IGP-II). At the end of the study, CG had a higher mean shortening fraction than the other groups had (p≤0.03). Left ventricular systolic diameter was lower in CG than in infarcted groups (p≤0.003). The infarcted groups had greater expression of TGF-β (p≤0.04). PM 2.5 increased the expression of TGF-β in the IGP-II compared with the MI group (p = 0.004). The TNF-α gene was overexpressed in the IGP-II compared with the CGP group (p = 0.012). INF-γ gene expression was greater in IGP-II (p≤0.01). Oxidative stress analysis showed a higher glutathione concentration in CGP (p = 0.03), MI (p = 0.014), and IGP-I (p = 0.008) compared with that in CG. Conclusions PM 2.5 stimulates the deposition of fibrosis in the myocardium of healthy hearts, but not in infarcted hearts. PM 2.5 modulates the inflammatory response, which was greater in the IGP-II group. It also modulates oxidative stress in healthy hearts but not in infarcted hearts.