Professor Miranda Orr of Winston Salem’s School of Medicine in North Carolina leads a team of investigators who have detected senescent cells in patients with Alzheimer’s disease. These cells, found in patients’ brains, are known as zombie cells.
According to a recent article in Medscape, researchers are showing an increased interest in “cell senescence” (arrested cell division). Their challenge in neurodegenerative dementia is to understand the connection between immune-associated genes and pathways and their contribution to disease.
The term senescence is derived from the Latin “Senex” meaning “old man.” Senescent cells do not die off. Instead, the cells stop dividing and build up in various tissues in the body. They have a resistance to cell death. Senescent cells also secrete inflammatory molecules that cause other cells to be senescent.
Dr. Orr’s study provides more evidence of how aging can contribute to Alzheimer’s. Many new treatments may be developed from this study. Researchers may find treatments to avert cell senescence or even remove them entirely. This would stop or slow Alzheimer’s progression.
Growing Old
One contributing factor to cells becoming senescent is exposure to stressors as people age. Research performed on animal models showed that diseases associated with aging were delayed when the number of senescent cells was reduced.
But attempting to detect senescent cells in human tissue is challenging, although researchers have met some of these challenges. They have used postmortem brain tissue and developed a technique for identifying cells called “eigengenes,” which are segments of DNA that bind to a chromosome.
Eigengenes are used when no gene can reliably capture senescence or other phenotype traits. Researchers reported that their eigengenes identified approximately two percent senescent cells from about 140,000 single nuclei taken from seventy-six human brains (postmortem).
Dr. Howard Fillit, the ADDF’s executive director, spoke of the research as being innovative and exciting. He said it is another method of targeting one of the many factors causing Alzheimer’s disease.
An estimated six million people in the U.S. are living with Alzheimer’s disease. There is an urgent need to find new therapies to target senescent cells, vascular dysfunction, and inflammation, along with other targets.
