ADVERTISEMENT

Investigating The Effects Of PM2.5 On Energy Metabolic Reprogramming

During the last two decades, air pollution has been regarded as one of the toughest challenges facing human beings. As the key indicator of air pollution, PM2.5 received great public concern. Exposure to PM2.5 could cause many adverse effects, such as allergies, diseases, or even death. Furthermore, it was reported that a 10 őľg/m3 increment in PM2.5 was associated with a 1.04% increase in the risk of death.

Because of the variation of composition and concentration of toxic substances adsorbed in the particles, the toxicity of PM2.5 showed obviously regional and seasonal differences. Until now, oxidative stress and inflammation were regarded as the most accepted mechanism to PM2.5-induced toxicity. Both transition metals and organic compounds contributed to ROS production and pro-inflammatory cytokines release. In cells, there are two pathways to supply energy, named glycolysis and oxidative phosphorylation. When the external environment changed, cells may rewrite the energy metabolic phenotype to adapt to the new circumstances and suppress damage.

ADVERTISEMENT

In this study, we found that exposure to PM2.5 could change energy metabolic phenotype from more effective oxidative phosphorylation to less-effective glycolysis. Mass spectrometry-based metabolomics was used to investigate the overall metabolic changes and relevant toxicological pathways. Consequently, purine metabolism, arginine and proline metabolism, glutathione metabolism, TCA cycle, and glycolysis were affected. The biological indices determination also showed that oxidative stress and inflammation played important roles in energy metabolism disorder.

Schematic overview of the disturbed metabolic pathways in BEAS-2B cells upon PM2.5 exposure. Molecules marked in red represented the up-regulated metabolites and in green represented the down-regulated metabolites. Credit: Zongwei Cai

The metabolites in the TCA cycle (e.g. succinate, malate) were found down-regulated, which indicated that the precursors for oxidative phosphorylation were reduced. The metabolites in glycolysis (e.g. lactate, fructose 1,6-bisphosphate) were up-regulated, which proved the promotion of glycolysis in cells. Interestingly, we found the change of TCA cycle and glycolysis were also influenced by other pathways.

Purine metabolism and glutathione metabolism have been reported to be closely related with oxidative stress. The level increase of metabolites within purine metabolism indicated the production of ROS, while excessive ROS could cause mitochondrial damage, which affected the supplement of energy. Arginine and proline metabolism have been found to be controlled by inflammation. On one hand, the release of TNF-őĪ could increase the expression of iNOS to generate nitric oxide in cells, and the accumulation of nitric oxide could compete with oxygen to reduce mitochondrial respiration. On the other hand, the conversion of arginine to urea cycle was inhibited, while some metabolites in urea cycle are the precursors of TCA cycle, so the decrease of urea cycle aggravated the reduction of TCA cycle.

In summary, the PM2.5 exposure caused the metabolic reprogramming and mitochondrial dysfunction by perturbing purine metabolism, arginine and proline metabolism, glutathione metabolism, TCA cycle, and glycolysis caused by oxidative stress and inflammation. Because endogenous metabolites are the terminal products of gene expression, metabolomics could be regarded as a powerful tool to provide the most ‚Äúfunctional‚ÄĚ information at the final level.

ADVERTISEMENT

These findings are described in the article entitled Mass spectrometry-based metabolomics reveals the mechanism of ambient fine particulate matter and its components on energy metabolic reprogramming in BEAS-2B cells, recently published in the journal Science of the Total Environment. This work was conducted by Yuanyuan Song, Yanhao Zhang, Juntong Wei, Wei Chen, and Chi Kong Arthur Chung from the Hong Kong Baptist University, Ruijin Li from Shanxi University, and Zongwei Cai from the Hong Kong Baptist University and the Guangdong University of Technology.

Comments

READ THIS NEXT

The Dark Matter Of The Brain Lights Up!

Published by Saak V. Ovsepian Department of Experimental Neurobiology at the National Institute of Mental Health, Klecany, Czech Republic These […]

California Hits 2020 Emissions Reduction Goal Two Years Ahead Of Schedule

California has reached another milestone in its efforts to cut emissions of greenhouse gases. Not only that, but California has […]

Table-Top Alternative To Synchrotrons: New Instrumentation To Study Radioactive Materials With Great Precision

The study of materials used in nuclear power plants is rendered difficult due to the high radioactivity of even a […]

Fuel For Regional Economies: What Are The Benefits Of Renewable Energies?

Climate change and its effects on our ecosystems and our economies is one of the main current and future challenges. […]

Wild Rice Populations: A Key Resource For Global Food Security

Published by Robert J. Henry Queensland Alliance for Agriculture and Food Innovation, University of Queensland These findings are described in […]

What Do Worms / Earthworms Eat?

Earthworms are tube-shaped segmented organisms that fall under the phylum¬†Annelida.¬†Contrary to popular perception, earthworms are¬†not¬†insects or arthropods‚ÄĒthey are animals. Earthworms […]

How Studying The Resting Brain Might Help Us Understand Why Night Owls Are At Increased Risk Of Developing Depression

It is estimated that 322 million people worldwide suffer from major depression every year. Depression is a serious mental health […]

Science Trends is a popular source of science news and education around the world. We cover everything from solar power cell technology to climate change to cancer research. We help hundreds of thousands of people every month learn about the world we live in and the latest scientific breakthroughs. Want to know more?