“Although everyone ages, not all of us age at the same rate, and our lived experiences, both negative and positive, can alter the rate of this aging. Corresponding author Noah Snyder-Mackler, an assistant professor at Arizona State University’s School of Life Sciences, said: “The early onset of some age-related diseases, like heart disease, is that we’re still alive.” It is not known exactly how these events enter our bodies leading to negative health effects that may not appear until decades after the event.”
As the ultimate impact on the mental and physical health of survivors remains unexamined, a team of biologists led by Snyder-Mackler looked at one of its closest evolutionary cousins. our close to find the first clue.
Along with the human toll, the devastation has affected all of the island’s wildlife, including a group of free-living macaques that live on isolated Cayo Santiago near Puerto Rico. These animals have lived on the island since 1938, when the Caribbean Primate Research Center’s field station first opened.
Now, the ASU team, led by Snyder-Mackler and lead author Marina Watowich, a graduate student at the University of Washington and research scientist at ASU, and their collaborators at the Center for Spiritual Research Chief of the Caribbean, University of Pennsylvania, University of Exeter and New York University, have published (which will include DOI) one of the first results showing that the impact of natural disasters can accelerate molecular aging in the monkey immune system.
Fast aging
As a Category 4 hurricane, Maria caused extensive damage to natural habitats and research infrastructure on Cayo Santiago. Notably, only 2.75% of the monkey population died immediately after the storm. And the year after the storm, there was no difference in survival. But, have the health of hurricane survivors been affected in other ways?
People of the same age – the number of years since birth – can differ in when and if they develop the disease. It is well established that people who have had extremely adverse experiences have a higher risk of developing heart disease and other diseases that are more common in older people. How these adverse experiences ‘get into the skin’ to promote disease remains a mystery. One idea is that this phenomenon is likely due to the “aging” of the body with extreme adversities. Everyone can vary in their biological age, which can be measured by molecular markers embedded in our genes, immune system, and physiology.
“From this study, we measured the molecular changes associated with aging, including disruption of protein-folding genes, and more inflammatory immune cell marker gene expression,” said Watowich. and greater biological aging.
After carefully analyzing the genes expressed in the monkey’s immune cells, the researchers found that stormy adversity may have accelerated the aging of the immune system.
“On average, monkeys that lived through the storm with immune gene expression profiles aged two more years, or about seven to eight years to a human’s lifespan,” said Watowich.
The findings suggest that extreme weather events – which are becoming more frequent and severe as a result of climate change – can lead to adverse biological consequences for those who experience them. . This is especially urgent because hurricanes and other extreme weather events are becoming stronger and more common with climate change.
Biological aging
A kilometer off Puerto Rico’s southeast coast is Cayo Santiago, a 15.2-hectare island home to 1,800 free-living macaques that have been studied for nearly a century.
“Cayo Santiago was the first area of Puerto Rico to be hit by Hurricane Maria and experience the full force of a Category 4 hurricane,” Snyder-Mackler said. “The storm destroyed homes and infrastructure across Puerto Rico, and in Cayo Santiago it destroyed most of the vegetation, as well as the water tanks and research infrastructure needed to sustain it. maintain the field station.”
The rhesus macaques share many behavioral and biological characteristics of humans, including the way their bodies age, but are compressed into a quarter of our lifespan. By studying macaques, the team knew they could get an estimate of aging in years, not decades, from similar studies in humans.
To examine how Hurricane Maria affects immune cell gene regulation and aging, Marina Watowich and the rest of the team were able to use a collection of blood samples and historical data. Detailed demographics from age-matched subsets of the Cayo Santiago rhesus macaque population.
By performing a global analysis of immune gene expression, they found that 4% of genes expressed in immune cells were altered after the storm. Among these, genes with higher expression after the storm were associated with inflammation, and the genes that were impaired by storm were those involved in protein translation, protein folding/restructuring, response adaptive immunity and T cells.
The down-regulation of so-called heat shock genes, which promote the proper function of making proteins in our cells, was affected the most, some with two times lower activity after Hurricane Maria. These genes have also been linked to cardiovascular disease and Alzheimer’s disease.
Remarkably, they found a strong correlation between storm exposure and the effects of aging on gene expression, where the effects of hurricanes are similar to those of the aging immune system. Go.
To understand how hurricanes might affect immune cell populations, they looked at records from single-cell RNA sequences to identify genes that are preferentially expressed in key immune cell types. .
“Overall, cell-specific markers of standard anti-inflammatory immune cells, such as CD14+ monocytes, are higher in expression in older adults and those who have experienced a hurricane. Furthermore, the expression of helper T-cell genes, a type of anti-inflammatory cell, adds Snyder-Mackler, which could similarly lead to greater pro-inflammatory activity in the animals following the storm. as we see in older individuals”.
Get under the skin
From their long-term studies, as part of a collaboration with the Caribbean Primate Research Center, the University of Pennsylvania, the University of Exeter, and New York University, they had data four years before Hurricane Maria ( n = 435) and one year later (n = 108) Hurricane Maria. They hypothesized that storm exposure would recapitulate the molecular changes associated with the natural aging process.
“Our findings suggest that differences in immune cell gene expression in individuals exposed to extreme natural disasters are in many ways similar to the effects of natural disasters,” said Snyder-Mackler. natural aging process,” says Snyder-Mackler. “We also observed evidence of a faster biological aging process in samples collected after the animals experienced Hurricane Maria.”
“It is important that we identify a key mechanism – immune cell gene regulation – that may explain how adversity, especially in the context of natural disasters, ultimately can be,” says Watowich. can ‘penetrate the skin’ to promote age-related disease onset and progression,” says Watowich.
Interestingly, not all monkeys responded similarly to the storm. For example, the biological age of some monkeys increased much more than that of others. The team hypothesizes that there may be other aspects of the monkeys’ habitat that could influence their response to adversity.
For example, as in humans, social support is an important aspect of our ability to help cope and cope with adversity. It’s possible that the monkeys who received more social support after the storm were better able to weather any adverse effects – an aspect the team hopes to investigate soon. The study, first of all, has its limitations: they cannot measure the aging rates of the same individuals before or after the storm.
For future studies, they hope the work can expand to include long-term studies of every individual in the population to learn more about the intersection between biological aging, adversity, and aging. social structures and in the face of natural disasters.
Ultimately, they hope their results will spur efforts to develop a better understanding of aging and adversity and, one day, even a successful mitigation strategy to reduce the damage caused by aging. caused by disaster.
Source: Eurekalert
