Posts tagged with "University of Illinois Chicago"

‘Zombie’ genes? Research shows some genes come to life in the brain after death

April 16, 2021

In the hours after we die, certain cells in the human brain are still active. Some cells even increase their activity and grow to gargantuan proportions, based on new research from the University of Illinois Chicago.

For the study—which has been published in the journal, Scientific Reports—the UIC researchers analyzed gene expression in fresh brain tissue (collected during routine brain surgery) multiple times after removal to simulate the post-mortem interval and death. They found that gene expression in some cells actually increased after death.

The “zombie genes”those that increased expression after the post-mortem interval— were specific to one type of cell: inflammatory cells called glial cellsm according to a report on the study by Science Daily. The researchers observed that glial cells grow and sprout long arm-like appendages for many hours after death.

“That glial cells enlarge after death isn’t too surprising given that they are inflammatory; and their job is to clean things up after brain injuries like oxygen deprivation or stroke,” said Dr. Jeffrey Loeb, the John S. Garvin Professor and head of Neurology and Rehabilitation at the UIC College of Medicine and corresponding author on the paper.

What’s significant, Loeb said, is the implications of this discovery: Most research studies that use postmortem human brain tissues to find treatments and potential cures for disorders such as autism, schizophrenia, and Alzheimer’s disease, do not account for the post-mortem gene expression or cell activity.

“Most studies assume that everything in the brain stops when the heart stops beating, but this is not so,” Loeb said. “Our findings will be needed to interpret research on human brain tissues. We just haven’t quantified these changes until now.”

Loeb and his team noticed that the global pattern of gene expression in fresh human brain tissue didn’t match any of the published reports of postmortem brain gene expression from people without neurological disorders or from people with a wide variety of neurological disorders, ranging from autism to Alzheimer’s.

“We decided to run a simulated death experiment by looking at the expression of all human genes, at time points from 0 to 24 hours, from a large block of recently collected brain tissues, which were allowed to sit at room temperature to replicate the postmortem interval,” Loeb said.

Loeb and colleagues are at a particular advantage when it comes to studying brain tissue. Loeb is director of the UI NeuroRepository, a bank of human brain tissues from patients with neurological disorders who have consented to having tissue collected and stored for research either after they die, or during standard of care surgery to treat disorders such as epilepsy. For example, during certain surgeries to treat epilepsy, epileptic brain tissue is removed to help eliminate seizures. Not all of the tissue is needed for pathological diagnosis, so some can be used for research. This is the tissue that Loeb and colleagues analyzed in their research.

They found that about 80% of the genes analyzed remained relatively stable for 24 hours. Their expression didn’t change much. These included genes often referred to as housekeeping genes that provide basic cellular functions and are commonly used in research studies to show the quality of the tissue. Another group of genes, known to be present in neurons and shown to be intricately involved in human brain activity such as memory, thinking,and seizure activity, rapidly degraded in the hours after death. These genes are important to researchers studying disorders such as schizophrenia and Alzheimer’s disease, Loeb said.

A third group of genes—the “zombie genes”—increased their activity at the same time the neuronal genes were ramping down. The pattern of post-mortem changes peaked at about 12 hours.

“Our findings don’t mean that we should throw away human tissue research programs, it just means that researchers need to take into account these genetic and cellular changes, and reduce the post-mortem interval as much as possible to reduce the magnitude of these changes,” Loeb said. “The good news from our findings is that we now know which genes and cell types are stable, which degrade, and which increase over time so that results from postmortem brain studies can be better understood.”

Research contact: @ScienceDaily

Going long: Study finds both Biden, Trump likely to be ‘super-agers’

September 29, 2020

Both 2020 presidential candidates—former Vice President Joe Biden, 77, and President Donald Trump, 74—are likely to maintain their health and cognitive functions beyond the end of the next presidential term, according to findings of a recent study published in the Journal on Active Aging, University of Illinois Chicago, Medical Xpress reports.

Indeed, longevity researcher S. Jay Olshansky and his colleagues have concluded that chronological age and fitness should not be factors in the 2020 election.

“It is our conclusion that chronological age is not a relevant factor for either candidate running for President of the United States,” the authors write. “Both candidates face a lower than average risk of experiencing significant health or cognitive functioning challenges during the next four years.”

To evaluate each candidate’s likelihood of surviving a four-year term in office, the researchers scientifically evaluated the candidates’ health status based on publicly available medical records and confirmed publicly available personal information. The medical records of each candidate were independently evaluated by three medical doctors with experience in aging and a team of research scientists with expertise in epidemiology, public health, survival analysis, and statistics.

This is the first time, Medical Xpress reports, that the medical records and personal attributes of presidential candidates have been scientifically evaluated by physicians and scientists in the field of aging.

The key findings of the study:

“We see chronological age as a topic of discussion time and again during elections, even though scientific and medical evidence tells us that biological age is far more important,” said Olshansky, professor of epidemiology and biostatics at the UIC School of Public Health.

Biological age is reflective of how rapidly a body is growing old—this occurs at different rates, Olshansky said. “Biological age is influenced by genetics and behavioral risk factors. Some people can be biologically old at age 50 while others can be biologically young at age 80.”

In prior research, Olshansky conducted the first scientific evaluation of presidential longevity; he sought to understand if being president causes an individual to age more rapidly and die sooner than expected. In that study, Olshansky concluded that most U.S. presidents actually live beyond the average life expectancy.

Research contact: @xpress_medical