Breaking News
February 18, 2019 - New dental adhesive prevents tooth decay around orthodontic brackets
February 18, 2019 - New eHealth tool shows potential to improve quality of asthma care
February 18, 2019 - New Australian initiative helps emergency clinicians to improve patient care
February 17, 2019 - Apellis Pharmaceuticals’ APL-2 Receives Fast Track Designation from the FDA for the Treatment of Patients with Paroxysmal Nocturnal Hemoglobinuria
February 17, 2019 - Researchers identify faulty ‘brake’ that interferes with heart muscle’s ability to contract and relax
February 17, 2019 - Support from trusted adults can reduce risk of dying in suicidal teens, finds study
February 17, 2019 - Heart attack awareness improved since 2008
February 17, 2019 - Exercise gives a better brain boost to older men than women
February 17, 2019 - New research disproves previous assumptions of how looks influence personality
February 17, 2019 - Cannabis use as a teenager linked to depression later in life
February 17, 2019 - Sinks by Toilets in ICU Patient Rooms Harbor Harmful Bacteria
February 17, 2019 - Cancer cells’ plasticity makes them harder to stop
February 17, 2019 - Young cannabis users have increased risk of depression and suicidal behavior
February 17, 2019 - Tasmanian Devils Likely to Survive Cancer Scourge
February 17, 2019 - Neoadjuvant PD-1 blockade seems effective in glioblastoma
February 17, 2019 - Personal, social factors play role in enabling sustainable return to work after ill health
February 17, 2019 - Mouse studies show ‘inhibition’ theory of autism wrong
February 17, 2019 - Study shows how neuroactive steroids inhibit activity of pro-inflammatory proteins
February 17, 2019 - Use of liver grafts from older donors decreased despite better outcomes in recipients
February 17, 2019 - MUSC researchers discover new mechanism for a class of anti-cancer drugs
February 17, 2019 - HPV misconceptions are causing women to miss smear tests
February 17, 2019 - Sanofi and Regeneron Offer Praluent (alirocumab) at a New Reduced U.S. List Price
February 17, 2019 - Researchers say auditory testing can identify children for autism screening
February 17, 2019 - New method analyzes how single biological cells react to stressful situations
February 17, 2019 - WVU gynecologic oncologist investigates novel treatment for cervical and vaginal cancers
February 17, 2019 - ADHD diagnoses poorly documented
February 17, 2019 - Majority of gender minority youth do not identify with traditional sexual identity labels
February 17, 2019 - AbbVie, Teneobio enter into strategic transaction to develop potential treatment for multiple myeloma
February 17, 2019 - Lower Birth Weight May Up Risk for Psychiatric Disorders
February 17, 2019 - Scientists identify reversible molecular defect underlying rheumatoid arthritis
February 17, 2019 - Moffitt researchers shed light on how CAR T cells function mechanistically
February 16, 2019 - Female Anatomy May Play Big Role in Sperm’s Success
February 16, 2019 - BMI may mediate inverse link between fiber intake, knee OA
February 16, 2019 - Movement impairments in autism can be reversed through behavioral training
February 16, 2019 - Studies address racial disparities in postpartum period and cardiovascular health
February 16, 2019 - Scientists implicate hidden genes in the severity of autism symptoms
February 16, 2019 - Decreased deep sleep linked to early signs of Alzheimer’s disease
February 16, 2019 - Neuroscientists show how the brain responds to texture
February 16, 2019 - Gilead Announces Topline Data From Phase 3 STELLAR-4 Study of Selonsertib in Compensated Cirrhosis (F4) Due to Nonalcoholic Steatohepatitis (NASH)
February 16, 2019 - What Can I Do About Sweating? (for Teens)
February 16, 2019 - Companies navigate dementia conversations with older workers
February 16, 2019 - Newly developed stem cell technologies show promise for treating PD patients
February 16, 2019 - Collaborative material research could advance self-assembling nanomaterials
February 16, 2019 - Researchers take major step in creating technology that mimics the human brain
February 16, 2019 - Erasing memories associated with cocaine use reduces drug seeking behavior
February 16, 2019 - Artificial intelligence can accurately predict prognosis of ovarian cancer patients
February 16, 2019 - Racial disparities in cancer deaths on the decline for America
February 16, 2019 - FDA authorizes new interoperable insulin pump for children, adults with diabetes
February 16, 2019 - Coexisting Medical Conditions, Smoking Explain PTSD-CVD Link
February 16, 2019 - Skin Cancer Screening: MedlinePlus Lab Test Information
February 16, 2019 - ‘Happiness’ exercises can boost mood in those recovering from substance use disorder
February 16, 2019 - Cell manipulation could soon halt or reverse aging
February 16, 2019 - Pumped Breast Milk Falls Short of Breastfed Version
February 16, 2019 - Men’s porn habits could fuel partners’ eating disorders, study suggests
February 16, 2019 - Rapid progression of age-related diseases may result from formation of vicious cycles
February 16, 2019 - Immune checkpoint molecule protects against future development of cancer
February 16, 2019 - New method produces hydrogels that have properties similar to cells’ environment
February 16, 2019 - $4.1 million funding for heart research on Valentine’s Day
February 16, 2019 - General anesthesia in early infancy unlikely to have lasting effects on developing brains
February 16, 2019 - New breakthroughs for muscular dystrophy research
February 16, 2019 - First Opinion: Embryo editing for higher IQ is a fantasy. Embryo profiling for it is almost here
February 16, 2019 - Vapers develop cancer-related gene deregulation as cigarette smokers
February 16, 2019 - Bringing Antimicrobial Susceptibility Testing (AST) to the Community
February 16, 2019 - Decolonization protocol after hospital discharge can prevent dangerous infections
February 16, 2019 - Children with ASD more likely to face maltreatment, study finds
February 16, 2019 - Study finds genetic vulnerability to use of menthol cigarettes
February 16, 2019 - Promising drug developed to rejuvenate muscle cells
February 16, 2019 - H-RT should be the standard of care for men with low risk prostate cancer, study shows
February 16, 2019 - New technique using patients’ own modified cells could help treat Crohn’s disease
February 16, 2019 - Therapeutic endoscopy has an expanding role in the treatment of IBD
February 16, 2019 - Blood clot discovery could lead to development of better treatments for blood diseases
February 16, 2019 - Intervention can increase exclusive breastfeeding rates
February 16, 2019 - New project explores how gaming technologies can help cancer patients communicate better
February 16, 2019 - Catalyst Biosciences Presents Updated Data from Its Phase 2/3 Trial of Subcutaneous Marzeptacog Alfa (Activated) in Individuals with Hemophilia A or B with Inhibitors at the 12th Annual EAHAD Congress
February 16, 2019 - Rerouting nerves during amputation reduces phantom limb pain before it starts
February 16, 2019 - A Hormone Produced When We Exercise Might Help Fight Alzheimer’s
February 16, 2019 - Millions of British people breathe toxic air travelling to GPs
February 16, 2019 - Conformance of genetic characteristics found to be crucial for longer preservation of kidney graft
February 16, 2019 - Researchers use optogenetic tool to control, visualize receptor signals in neural cells
February 16, 2019 - New reversible antiplatelet therapy could reduce risk of blood clots, prevent cancer metastasis
Study reveals how apoE4 gene confers risk for Alzheimer’s disease in brain cells

Study reveals how apoE4 gene confers risk for Alzheimer’s disease in brain cells

image_pdfDownload PDFimage_print

Using human brain cells, scientists at the Gladstone Institutes discovered the cause of–and a potential solution for–the primary genetic risk factor for Alzheimer’s disease, a gene called apoE4.

Having one copy of the apoE4 gene more than doubles a person’s likelihood of developing Alzheimer’s disease, and having two copies of the gene increases the risk by 12-fold, as compared to the most common version of the gene, apoE3.

The apoE4 gene creates a protein of the same name. The apoE4 protein differs from the apoE3 protein at only one point, but that single change is enough to alter its main structure and, thus, its function. Scientists have been unclear about why apoE4 is so much more damaging to brain cells than other versions of the protein.

In a new study published in Nature Medicine, researchers revealed how apoE4 confers its risk for Alzheimer’s disease in human brain cells. What’s more, they were able to erase the damage caused by apoE4 by changing it, with a small molecule, into a harmless apoE3-like version.

A Better Model

Most Alzheimer’s research and drug development are done in mouse models of the disease. However, a succession of clinical trial failures has spurred scientists to turn to other models.

“Drug development for Alzheimer’s disease has been largely a disappointment over the past 10 years,” says lead author Yadong Huang, MD, PhD, a senior investigator and director of the Center for Translational Advancement at Gladstone. “Many drugs work beautifully in a mouse model, but so far they’ve all failed in clinical trials. One concern within the field has been how poorly these mouse models really mimic human disease.”

Instead, Huang decided to use human cells to model the disease and test new drugs. Thanks to induced pluripotent stem cell technology, his team was able to examine, for the first time, the effect of apoE4 on human brain cells. To do so, the researchers created neurons from skin cells donated by Alzheimer’s patients with two copies of the apoE4 gene, as well as from healthy individuals who had two copies of the apoE3 gene.

The researchers confirmed that, in human neurons, the misshapen apoE4 protein cannot function properly and is broken down into disease-causing fragments in the cells. This process results in a number of problems commonly found in Alzheimer’s disease, including the accumulation of the protein tau and of amyloid peptides.

Notably, the presence of apoE4 does not change the production of amyloid beta in mouse neurons. But in human cells, scientists noticed apoE4 has a very clear effect on increasing amyloid beta production, which highlights the species difference in the way apoE4 controls amyloid beta metabolism.

“There’s an important species difference in the effect of apoE4 on amyloid beta,” says Chengzhong Wang, PhD, the first author on the paper and former research scientist at Gladstone. “Increased amyloid beta production is not seen in mouse neurons and could potentially explain some of the discrepancies between mice and humans regarding drug efficacy. This will be very important information for future drug development.”

Fixing a Toxic Protein

Once the scientists confirmed that apoE4 does, indeed, cause damage in human cells related to Alzheimer’s disease, a key question remained: how does the presence of apoE4 lead to cell damage? Is the presence of apoE4 resulting in a loss of normal apoE3 function, or does the addition of apoE4 cause the toxic effects?

“It’s fundamentally important to address this question because it changes how you treat the problem,” explains Huang, who is also a professor of neurology and pathology at UC San Francisco. “If the damage is caused due to the loss of a protein’s function, you would want to increase protein levels to supplement those functions. But if the accumulation of a protein leads to a toxic function, you want to lower production of the protein to block its detrimental effect.”

To answer this question, the researchers examined brain cells that did not produce either form of the apoE protein, and the neurons looked and functioned just like cells with apoE3. However, if the researchers added apoE4, the cells became riddled with pathologies related to Alzheimer’s disease. This discovery indicates that the presence of apoE4–and not the absence of apoE3–promotes the disease.

Finally, the researchers looked for ways to repair the abnormalities caused by apoE4. In earlier work, Huang and his collaborators developed a class of compounds that can change the structure of the harmful apoE4 protein so it resembles the innocuous apoE3 protein, referred to as apoE4 “structure correctors”.

Treating human apoE4 neurons with a structure corrector eliminated the signs of Alzheimer’s disease, restored normal function to the cells, and improved cell survival. Huang is now working with his collaborators in academia and the pharmaceutical industry to improve the compounds so they can be tested in human patients in the future.​​​

Source:

https://gladstone.org/about-us/news/scientists-fix-genetic-risk-factor-alzheimers

Tagged with:

About author

Related Articles