Low particle pollution can be dangerous, too
Even the smallest particles in the air, the particulate matter that can be measured in a particle counter, can cause lung inflammation and potentially disease. A new study shows even low levels of air pollution can induce gene expression in the same cells that make up our bodies.
This has important implications for how we view air pollution, says Dr. Lawrence S. Harrit, a professor of environmental health sciences at Harvard T.H. Chan School of Public Health and the study’s senior author.
“These findings show that even a low level of air pollution, like a reading on a particle counter, can cause lung inflammation and disease,” says Harrit, who is also an investigator with the Howard Hughes Medical Institute’s Office of Basic Energy Sciences.
Harrit’s research was published in the Journal of the American Medical Association (JAMA) on March 18.
The results are significant because the same mechanism could be used to treat the disease by using the same medicines, says Harrit.
To determine whether the gene expression of lung cells is changed by air pollution, Harrit’s team studied cells taken from people with chronic obstructive pulmonary disease (COPD). The researchers exposed the cells to air pollution, but did not expose them to a control group. The team also measured the cells’ genes using a gene-editing technique called CRISPR/Cas9.
The team found that the levels of several genes in the cells that make up lung tissue were significantly reduced by air pollution. However, they found that there was no significant change in the levels of these genes in cells that did not make up lung tissue. This suggests that the mechanisms that regulate the genes were not affected by air pollution.
“We’re not suggesting that we know how to treat COPD by editing the genes of the cells that make up the lung tissue, but we can learn a lot about how to manipulate those genes,” says Harrit.
Further experiments showed that the genes that were affected by air pollution were associated with genes that are involved in a type of protein known as lipid rafts. These rafts are a kind of cell membrane that keeps other molecules inside the cell, such as proteins, out. The lipid rafts also allow cells to move fluid around the cell.
The team then used a technique called mass spectrometry to identify the lipid rafts in the cells. They found that the molecules they found were made by cells that make up lung tissue.
Hiromi Wakayama, a chemist at the Massachusetts Institute of Technology in Cambridge, says that the research could have implications for other types of diseases.
“This is a very interesting and novel study, which is based on a novel assay that allows you to look at cell populations that have different types of effects from air pollution,” says Wakayama, who was not involved in the research.