Breaking News
April 25, 2019 - Cardiometabolic Risk Better ID’d in Children Reclassified to Higher BP
April 25, 2019 - How the obesity epidemic is taking a toll on our bones and joints
April 25, 2019 - E-cigarettes contaminated with dangerous microbial toxins
April 25, 2019 - Researchers document specific characteristics of storefront tobacco advertisements
April 25, 2019 - Oncotype DX-guided treatment could reduce cost for breast cancer care, study suggests
April 25, 2019 - New review highlights how lifestyle affects our genes
April 25, 2019 - Study provides evidence that blood tests can detect Alzheimer’s risk
April 25, 2019 - Physicians turning to antibiotic alternatives for long-term acne treatment
April 25, 2019 - Preschool Is Prime Time to Teach Healthy Lifestyle Habits
April 25, 2019 - Study finds insidious and persistent discrimination among physician mothers
April 25, 2019 - Newly identified skin-gut communication helps illuminate link between food allergy and eczema
April 25, 2019 - Thiazide use linked with reduced risk of low energy fractures in people with Alzheimer’s
April 25, 2019 - Some women are biologically more resilient than others to PTSD
April 25, 2019 - The Current issue of “The view from here” is concerned with Partnerships and Alliances
April 25, 2019 - Imaging method reveals long-lived patterns in cells of the eye
April 25, 2019 - Podcast: KHN’s ‘What The Health?’ The Abortion Wars Rage On
April 25, 2019 - Prolonged exposure therapy is more effective in treating veterans with PTSD, alcohol use disorder
April 24, 2019 - Our artificial cornea breakthrough could lead to self-assembling organs
April 24, 2019 - A Stanford black, female, gay surgery resident speaks out
April 24, 2019 - Donna Lynne on Extreme Sports, Lessons From the '60s, and Taking CUIMC to the Next Level
April 24, 2019 - Pain Clinics’ Doctors Needlessly Tested Hundreds Of Urine Samples, Court Records Show
April 24, 2019 - Researchers uncover potential clue to halt destruction of nerve cells in people with ALS
April 24, 2019 - Study uncovers reasons for poor mental health in bisexual people
April 24, 2019 - Screenings, interventions, and referrals can help adolescents overcome substance abuse
April 24, 2019 - Febrile seizures following vaccination are self-resolving and not dangerous
April 24, 2019 - Flow-UV inline UV-Visible spectrometer monitors dispersion in real time
April 24, 2019 - Rates of Marijuana Use in Cancer Patients on the Rise in U.S.
April 24, 2019 - Versatile drug may protect baby from hazards of intraamniotic infections
April 24, 2019 - Financial transparency may diminish trust in doctors, new study finds
April 24, 2019 - Calling all Riders: Velocity Extends Free Registration 
April 24, 2019 - The Homeless Are Dying In Record Numbers On The Streets Of L.A.
April 24, 2019 - Researchers use brain scans to provide better understanding of unconscious bias
April 24, 2019 - Blocking BRAF ubiquitination may be an effective treatment approach in melanoma
April 24, 2019 - Simple mobility test helps predict hospital readmission in elderly heart attack patients
April 24, 2019 - Novel fluorescence imaging system helps surgeons remove small ovarian tumors
April 24, 2019 - Uncovering the Structure of HIV Integrase to Inform Drug Discovery
April 24, 2019 - Medical Marijuana Use Rising Among Cancer Patients
April 24, 2019 - Artificial intelligence approach optimizes embryo selection for IVF
April 24, 2019 - Doctor or detective? Sleuthing mysteries in medical school
April 24, 2019 - CUIMC Community Gives Blood During Spring 2019 Columbia University Blood Drive
April 24, 2019 - Americans Overwhelmingly Want Federal Protections Against Surprise Medical Bills
April 24, 2019 - Making Laboratories More Efficient with the Most Modern LIMS on the Market
April 24, 2019 - Treating cancer patients with personalized, combination therapies improves outcomes
April 24, 2019 - Researchers engineer new molecules to help stop lung cancer
April 24, 2019 - Acupuncture can be a wonderful tool for preventing number of diseases
April 24, 2019 - Daily life disability before hip replacement may predict poor post-operative outcomes
April 24, 2019 - Study finds involuntary staying in housing estates to be a potential health risk
April 24, 2019 - Older kidney disease patients starting dialysis die at higher rates than previously thought
April 24, 2019 - Time-restricted eating shows promise for controlling blood glucose levels
April 24, 2019 - Ambiguous genitalia in newborns may be more common than previously thought
April 24, 2019 - Research provides important insight on the brain-body connection
April 24, 2019 - In 10 Years, Half Of Middle-Income Elders Won’t Be Able To Afford Housing, Medical Care
April 24, 2019 - Researchers study how E. coli clones have become major cause of drug-resistant infections
April 24, 2019 - Bacterial and fungal toxins found in popular electronic cigarettes
April 24, 2019 - Factors affecting absorption of ‘sunshine vitamin’ during spring/summer months
April 24, 2019 - Texting helps improve medication adherence, health outcomes for patients with schizophrenia
April 24, 2019 - Cochrane Review looks at different ways to use nicotine replacement therapies
April 24, 2019 - New review on relationship between COPD and Type 2 diabetes
April 24, 2019 - Brain areas linked to memory and emotion aid odor navigation in humans
April 24, 2019 - Brain stimulation reverses age-related memory loss
April 24, 2019 - Amid Opioid Prescriber Crackdown, Health Officials Reach Out To Pain Patients
April 24, 2019 - $4 million NIH award will help establish UCI Skin Biology Resource-based Center
April 24, 2019 - Cancer drugs reprogram genes in breast tumors to prevent endocrine resistance, finds study
April 24, 2019 - Combination-imaging technique provides new window into macaque brain connections
April 24, 2019 - Researchers identify new allergen responsible for allergy to durum wheat
April 24, 2019 - Researchers define role of rare, influential cells in the bone marrow
April 24, 2019 - DNA rearrangement may predict poor outcomes in multiple myeloma
April 24, 2019 - FDA Approves Skyrizi (risankizumab-rzaa) for Moderate to Severe Plaque Psoriasis
April 24, 2019 - Combination therapy might be beneficial in schizophrenia
April 24, 2019 - Blood test can help match cancer patients to early phase clinical trials
April 24, 2019 - Women tend to underreport snoring and underestimate its loudness
April 24, 2019 - Comprehensive molecular test introduced for diagnosis of malaria caused by P. vivax parasites
April 24, 2019 - New range prediction approach increases accuracy, safety and tolerability of proton therapy
April 24, 2019 - Need for Sedation Up for Regular Cannabis Users
April 24, 2019 - Lack of access to antibiotics is a major global health challenge
April 24, 2019 - New study provides better understanding on safety of deworming programs
April 24, 2019 - EEG used to detect impact of maternal stress on neurodevelopment in 2-month-old infants
April 24, 2019 - FDA Approves First Generic Naloxone Nasal Spray Against Opioid Overdose
April 24, 2019 - A new way of finding compounds that prevent aging
April 24, 2019 - Mechanical training makes synthetic hydrogels perform more like muscle
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