Breaking News
November 14, 2018 - Appendix removal is linked to lower risk of Parkinson’s
November 14, 2018 - Lifting weights for less than an hour a week may reduce cardiovascular disease risk
November 14, 2018 - Pulmonary rehabilitation rarely received by hospitalized COPD patients despite health benefits
November 14, 2018 - New anti-HER2 drug shows promising anti-tumor activity in gullet, stomach and bowel cancers
November 14, 2018 - Brigham investigators examine opioid use among Massachusetts adolescents, prescription trends
November 14, 2018 - Study defines biomarker in response to treatment of castration-resistant prostate cancer
November 14, 2018 - Study identifies potential therapeutic strategy for patients with clear cell renal cancer
November 14, 2018 - Bausch Health Announces U.S. Launch of Bryhali (halobetasol propionate) Lotion, 0.01%, for Plaque Psoriasis In Adults
November 14, 2018 - Alpha Fetoprotein (AFP) Tumor Marker Test: MedlinePlus Lab Test Information
November 14, 2018 - Researchers evaluate controversial treatment for Parkinson’s disease psychosis
November 14, 2018 - AI could help veterinarians code their notes
November 14, 2018 - Pre-schoolers with autism thrive in mainstream classroom settings
November 14, 2018 - Individual and work-related factors may help promote hospital physician engagement, finds study
November 14, 2018 - Complementary and alternative medicine is widely used by general population in England
November 14, 2018 - Study reveals link between tobacco availability and smoking during pregnancy
November 14, 2018 - Purdue researchers develop translucent base for silicon patches to deliver exact doses of biomolecules
November 14, 2018 - New technology based on moths and magnets could help treat genetic diseases
November 14, 2018 - Concussion-Related Biomarkers Vary Based on Sex, Race
November 14, 2018 - One more year of high school may shape waistlines later in life
November 14, 2018 - Dissecting high drug costs – Scope
November 14, 2018 - Study shows novel strategy to reduce breast cancer bone metastasis
November 14, 2018 - Empowering the NHS through Industry Partnerships
November 14, 2018 - One size does not fit all in obesity treatment, study finds
November 14, 2018 - Seeking ways to prevent ‘secondary cataracts’
November 14, 2018 - Change Within the Eye May Be Early Warning for Macular Degeneration
November 14, 2018 - Study of 500,000 people clarifies the risks of obesity
November 14, 2018 - Ultrasound releases drug to alter activity in targeted brain areas in rats | News Center
November 14, 2018 - Umass Amherst researchers battle against youth suicide in rural Alaska Native communities
November 14, 2018 - Cancer stem cells depend on amino acid metabolism, and it’s proving to be their Achilles’ heel
November 14, 2018 - Epigenetic link found between prenatal exposure to maternal smoking and offspring’s cardio-metabolic health
November 14, 2018 - Meditation, music may change biomarkers of cellular aging and Alzheimer’s disease in older adults
November 14, 2018 - Multidisciplinaryresearch teams selected to study age-related brain disorders
November 14, 2018 - The Current issue of “The view from here” is concerned with Informatics
November 14, 2018 - Researchers identify tool to help transgender women have a more authentic voice
November 14, 2018 - Four faculty members appointed to endowed professorships | News Center
November 13, 2018 - Research finds strongest evidence yet that obesity causes depression
November 13, 2018 - Researchers compare stools of breastfed and formula-fed infants
November 13, 2018 - Entasis Therapeutics Announces Zoliflodacin Phase 2 Results Published in The New England Journal of Medicine
November 13, 2018 - Gene changes driving myopia reveal new focus for drug development
November 13, 2018 - $6 million grant to support study of preeclampsia, atherosclerosis links | News Center
November 13, 2018 - Beneficial gut microbes metabolize high-fiber diet to improve heart health in mouse model
November 13, 2018 - Excessive use of social media through visual postings linked to increase in narcissistic traits
November 13, 2018 - Study finds why obesity both fuels cancer growth and helps immunotherapy to kill tumors
November 13, 2018 - Women prefer and invest more in daughters, while men favor sons
November 13, 2018 - With hospitalization losing favor, judges order outpatient mental health treatment
November 13, 2018 - Transgenic rat model may provide new insights into cerebral amyloid angiopathy
November 13, 2018 - Study identifies factors tied to greater risk of advanced liver disease in cystic fibrosis patients
November 13, 2018 - Risk of blindness among premature babies with low levels of blood platelets
November 13, 2018 - A new strategy for combatting antibiotic-resistant infections
November 13, 2018 - Study aims to find which outreach method is more effective at improving cancer screening rates
November 13, 2018 - Insufficient sleep duration linked with unhealthy lifestyle profile among children
November 13, 2018 - IIASA researchers introduce new, simple measure for human wellbeing
November 13, 2018 - Magnetic nanosprings used as targeted drug delivery agents for anticancer therapy
November 13, 2018 - Scientists examine FCMs containing silver nanoparticles
November 13, 2018 - Failed DNA repair triggers chromosomal chaos
November 13, 2018 - Study shows new emerging role of osteopontin in HCV-related hepatocellular carcinoma
November 13, 2018 - Food insecurity during pregnancy linked to severity of neonatal abstinence syndrome
November 13, 2018 - Majority of Americans are concerned about health threat posed by antibiotic resistance
November 13, 2018 - Addition of Elotuzumab Ups PFS in Refractory Multiple Myeloma
November 13, 2018 - Study finds women with pregnancy-related nausea, vomiting use marijuana more
November 13, 2018 - Lethal heart rhythm more likely to be found in patients with common heart failure
November 13, 2018 - Study provides new clues to origin and development of multiple sclerosis
November 13, 2018 - Climate change could pose threat to male fertility
November 13, 2018 - Researchers discover how mitochondria deploy a powerful punch against disease-causing bacteria
November 13, 2018 - AHA: Traumatic Childhood Could Increase Heart Disease Risk in Adulthood
November 13, 2018 - Feeling the Burn? | NIH News in Health
November 13, 2018 - Women’s birth canals in Kenya, Korea, Kansas not the same: study
November 13, 2018 - Fecal microbiota transplantation effective against ICI-associated colitis
November 13, 2018 - New physical activity guidelines released that urge people to “move more”
November 13, 2018 - Angiotensin receptor blockers improve sodium excretion in blacks
November 13, 2018 - New project seeks to address alarming injury rate in youth footballers
November 13, 2018 - Fish oil or omega 3 fatty acid supplements can prevent heart attacks finds study
November 13, 2018 - The Human Heart-in-a-Jar That Could One Day Replace Animal Testing
November 13, 2018 - Treat patients’ partners without a doctor visit
November 13, 2018 - Belgian beer landscape mapped using scientific insights
November 13, 2018 - ‘Master key’ gene has links to both ASD and schizophrenia
November 13, 2018 - Gladstone scientists gain new insights into the aging brain
November 13, 2018 - Drug therapy can improve outcomes for acutely ill heart patients
November 13, 2018 - Three landmark studies provide better understanding of sudden cardiac arrest
November 13, 2018 - Cholesterol control revised in the latest AHA/ACC guidelines
Stressed, toxic, zombie cells seen for first time in Alzheimer’s

Stressed, toxic, zombie cells seen for first time in Alzheimer’s

image_pdfDownload PDFimage_print
Miranda Orr, Ph.D., of UT Health San Antonio, led research showing cell stress called senescence is present in Alzheimer’s disease and is linked to tau protein tangles in the brain disorder. Credit: UT Health San Antonio

A type of cellular stress known to be involved in cancer and aging has now been implicated, for the first time, in Alzheimer’s disease. UT Health San Antonio faculty researchers reported the discovery Monday [August 20, 2018] in the journal Aging Cell.

The team found that the stress, called cellular senescence, is associated with harmful tau protein tangles that are a hallmark of 20 human brain diseases, including Alzheimer’s and traumatic brain injury. The researchers identified senescent cells in postmortem brain tissue from Alzheimer’s patients and then found them in postmortem tissue from another brain disease, progressive supranuclear palsy.

Cellular senescence allows the stressed cell to survive, but the cell may become like a zombie, functioning abnormally and secreting substances that kill cells around it. “When cells enter this stage, they change their genetic programming and become pro-inflammatory and toxic,” said study senior author Miranda E. Orr, Ph.D., VA research health scientist at the South Texas Veterans Health Care System, faculty member of the Sam and Ann Barshop Institute for Longevity and Aging Studies, and instructor of pharmacology at UT Health San Antonio. “Their existence means the death of surrounding tissue.”

Improvements in brain structure and function

The team confirmed the discovery in four types of mice that model Alzheimer’s disease. The researchers then used a combination of drugs to clear senescent cells from the brains of middle-aged Alzheimer’s mice. The drugs are dasatinib, a chemotherapy medication that is U.S. Food and Drug Administration-approved to treat leukemia, and quercetin, a natural flavonoid compound found in fruits, vegetables and some beverages such as tea.

After three months of treatment, the findings were exciting. “The mice were 20 months old and had advanced brain disease when we started the therapy,” Dr. Orr said. “After clearing the senescent cells, we saw improvements in brain structure and function. This was observed on brain MRI studies (magnetic resonance imaging) and postmortem histology studies of cell structure. The treatment seems to have stopped the disease in its tracks.”

“The fact we were able to treat very old mice and see improvement gives us hope that this treatment might work in human patients even after they exhibit symptoms of a brain disease,” said Nicolas Musi, M.D., study first author, who is Professor of Medicine and Director of the Sam and Ann Barshop Institute at UT Health San Antonio. He also directs the VA-sponsored Geriatric Research, Education and Clinical Center (GRECC) in the South Texas Veterans Health Care System.

Typically, in testing an intervention in Alzheimer’s mice, the therapy only works if mice are treated before the disease starts, Dr. Musi said.

Tau protein accumulation is responsible

In Alzheimer’s disease, patient brain tissue accumulates tau protein tangles as well as another protein deposit called amyloid beta plaques. The team found that tau accumulation was responsible for cell senescence. Researchers compared Alzheimer’s mice that had only tau tangles with mice that had only amyloid beta plaques. Senescence was identified only in the mice with tau tangles.

In other studies to confirm this, reducing tau genetically also reduced senescence. The reverse also held true. Increasing tau genetically increased senescence.

Importantly, the drug combination reduced not only cell senescence but also tau tangles in the Alzheimer’s mice. This is a drug treatment that does not specifically target tau, but it effectively reduced the tangle pathology, Dr. Orr said.

“When we looked at their brains three months later, we found that the brains had deteriorated less than mice that received placebo control treatment,” she said. “We don’t think brain cells actually grew back, but there was less loss of neurons, less brain ventricle enlargement, improved cerebral blood flow and a decrease in the tau tangles. These drugs were able to clear the tau pathology.”

Potentially a therapy to be tested in humans

“This is the first of what we anticipate will be many studies to better understand this process,” Dr. Musi said. “Because these drugs are approved for other uses in humans, we think a logical next step would be to start pilot studies in people.”

The drugs specifically target—and therefore only kill—the senescent cells. Because the drugs have a short half-life, they are cleared quickly by the body and no side effects were observed.

Dasatinib is an oral medication. The mice were treated with the combination every other week. “So in the three months of treatment, they only received the drug six times,” Dr. Orr said. “The drug goes in, does its job and is cleared. Senescent cells come back with time, but we expect that it would be possible to take the drug again and be cleared out again. That’s a huge benefit—it wouldn’t be a drug that people would have to take every day.”

Dosage and frequency in humans would need to be determined in clinical trials, she said.

Next, the researchers will study whether cell senescence is present in traumatic brain injury. TBI is a brain injury that develops tau protein accumulation and is a significant cause of disability in both military and non-military settings, Dr. Orr said.


Explore further:
Senolytic drugs reverse damage caused by senescent cells in mice

More information:
Nicolas Musi et al, Tau protein aggregation is associated with cellular senescence in the brain, Aging Cell (2018). DOI: 10.1111/acel.12840

Journal reference:
Aging Cell

Provided by:
University of Texas Health Science Center at San Antonio

Tagged with:

About author

Related Articles