Chronic exposure to polluted urban air aggravates myocardial infarction by impaired cardiac mitochondrial function and dynamics, 2021, Marchini et al

In mice.

Highlights

• A chronic exposure to urban air impairs lung redox metabolism and immunity.
• Alveolar macrophages readily uptake air pollution particulate matter.
• Exposure to urban air alters cardiac mitochondrial ultrastructure and function.
• Mitochondrial dynamics is blunted in the heart of mice exposed to urban air.
• A chronic exposure to urban air aggravates myocardial ischemia reperfusion injury.

Abstract

Air pollution exposure positively correlates with increased cardiovascular morbidity and mortality rates, mainly due to myocardial infarction (MI). Herein, we aimed to study the metabolic mechanisms underlying this association, focusing on the evaluation of cardiac mitochondrial function and dynamics, together with its impact over MI progression.

An initial time course study was performed in BALB/c mice breathing filtered air (FA) or urban air (UA) in whole-body exposure chambers located in Buenos Aires City downtown for up to 16 weeks (n = 8 per group and time point). After 12 weeks, lung inflammatory cell recruitment was evident in UA-exposed mice. Interestingly, impaired redox metabolism, characterized by decreased lung SOD activity and increased GSSG levels and NOX activity, precede local inflammation in this group. At this selected time point, additional mice were exposed to FA or UA (n = 12 per group) and alveolar macrophage PM uptake and nitric oxide (NO) production was observed in UA-exposed mice, together with increased pro-inflammatory cytokine levels (TNF-α and IL-6) in BAL and plasma.

Consequently, impaired heart tissue oxygen metabolism and altered mitochondrial ultrastructure and function were observed in UA-exposed mice after 12 weeks, characterized by decreased active state respiration and ATP production rates, and enhanced mitochondrial H2O2 production. Moreover, disturbed cardiac mitochondrial dynamics was detected in this group.

This scenario led to a significant increase in the area of infarcted tissue following myocardial ischemia reperfusion injury in vivo, from 43 ± 3% of the area at risk in mice breathing FA to 66 ± 4% in UA-exposed mice (n = 6 per group, p < 0.01), together with a sustained increase in LVEDP during myocardial reperfusion.

Taken together, our data unravel cardiac mitochondrial mechanisms that contribute to the understanding of the adverse health effects of urban air pollution exposure, and ultimately highlight the importance of considering environmental factors in the development of cardiovascular diseases.

Paywall, https://www.sciencedirect.com/science/article/abs/pii/S0269749121022594

 

Pollution through many routes scares me a lot…

 

It will always amaze me that it's been known for a long time that pollution kills millions per year, but it's basically unimaginable that it could cause other health problems, certainly not chronic health problems, other than maybe asthma, or aggravating existing respiratory illness, never really thinking of the possibility of causing them. It could possibly be the major driver behind most cardiovascular deaths, and it's basically treated on the same level as Lyme disease.

There's a serious metaphor to continuing to obsess over magical psychology being massively important, a mostly made-up problem invented by unimaginative people, while missing out the very real, but invisible to the naked eye, problem of pollution. One is "invisible", although actually possible to measure and evaluate. The other is completely made-up and impossible to measure in any way.

And which one is supremely important and the other conspiracy-mongering? Yeah... not great. Not great in the 21st century.

 

Yeah it’s the whole let’s make sure the polluters don’t pay, isn’t it?

Infectious disease? Well should be more careful.

Need treatment cause you can’t work and you’re very sick? So sorry should of been richer shouldn’t you?

Hardly anyone believes that one’s psychological condition has unmediated power to give one heart disease. Or any other disease. But a great many are prepared to pretend that they do. For the right remuneration.

 

I do think it’s interesting that we people in many countries, can be convinced to allow the very air we breathe to be poisoned and still we support the poisoners over the poisoned.