Jerold Chun, MD, PhD, has been awarded a new grant for $250,000 from the Coins for Alzheimer’s Research Trust (CART) Fund, an initiative by Rotary International to encourage exploratory and developmental Alzheimer’s research projects. Chun’s two-year project will explore how virus-like elements in our DNA could play a role in the development of Alzheimer’s disease.

“We are so grateful for the support of CART and the Rotarians,” says Chun. “They’ve shown over the years that small contributions to Alzheimer’s research can add up to make a huge impact.”

Ancient viruses in our genome
Chun’s project will explore how Alzheimer’s disease relates to endogenous genes in our genome that are very similar to parts of modern viruses. This is because they originated from viruses that infected our ancient ancestors. Over millions of years of evolution, these viruses became a normal part of our genomic makeup. 

Chun and other researchers suspect that these viral-like genes may be able to form virus-like particles that move through connections among our brain cells. They hypothesize that this process could promote neurodegenerative diseases like Alzheimer’s. “This new grant from CART will help us figure out how these genes and particles work, which is a first step toward thinking about how we might leverage it for treatments.”

Funding research with spare change
CART began in the mid-1990s with an ambitious idea: Could collecting the pocket change of Rotary International members accumulate enough to support Alzheimer’s disease?

The idea was launched in 1996 at Rotary Clubs in South Carolina; and at every meeting, members were asked to donate their loose change to a fund for Alzheimer’s research. The idea exploded from there. Over time, individual clubs started donating portions of their fundraising proceeds, and donations even began to come in from non-Rotary members as CART’s reputation grew.

The fund has awarded more than $10 million in grants to more than 40 institutions since its inception. This year, one of those grants was awarded to Chun to explore a new direction for Alzheimer’s research. This is the first CART grant to be awarded to a Sanford Burnham Prebys researcher.

“Grants like this are important because they give scientists the resources to pursue brand-new research areas,” says Chun. “Every major scientific discovery starts somewhere, and this type of support gives us that starting place, for which we’re really grateful.”

Sanford Burnham Prebys scientist publishes two papers that bring us one step closer to understanding—and potentially treating—the devastating condition.

For millions of families and caregivers around the world, the need for an effective treatment for Alzheimer’s disease remains urgent despite the ongoing pandemic. Now, two studies from Timothy Huang, PhD, who was recently promoted to assistant professor in the Degenerative Diseases Program at Sanford Burnham Prebys, bring us one step closer to understanding the root cause of the disease.  
 

Brain protein may help protect against Alzheimer’s disease  

Previous research from Huang and his colleagues showed that a neuronal protein called SORLA helps reduce production of toxic amyloid beta protein that accumulates and leads to Alzheimer’s disease. Given this important role, Huang decided to dig deeper to understand SORLA’s “job” inside the brain.

In a paper featured on the cover of The Journal of Neuroscience, Huang and his team analyzed mice that produce high levels of SORLA and studied the effects of enhancing SORLA on the brain. This work showed that higher levels of SORLA resulted in elongated neurites, structures that extend from neurons, and improved the repair and regeneration of axons—the cable-like fibers that neurons use to communicate. These findings suggest that drugs that increase levels of SORLA might help protect the brain against Alzheimer’s disease and may even help people with a spinal cord injury. 

Huang describes the findings as “the tip of the iceberg” and is eager to learn more about this important protein—with the ultimate goal of identifying potential targets for drugs that could slow the progression of Alzheimer’s disease. 
 

A new model for studying Alzheimer’s disease 

Many of the mutations associated with Alzheimer’s disease are found in a brain cell type called microglia. However, unlike other cells, mouse microglia are very different from human microglia. Because scientists primarily use mouse models to understand disease, this difference limits their ability to understand how microglial mutations lead to Alzheimer’s disease.  

To overcome this hurdle, Huang and his team took on the formidable task of creating human stem cell lines that contain Alzheimer’s mutations found in human microglia. The scientists then tracked the downstream effects of these mutations in the cells, including epigenetic and gene expression changes, which revealed many new, previously unknown relationships between Alzheimer’s-associated genes. The findings were published in the Journal of Experimental Medicine. 

More studies are needed to fully understand the how these interactions alter the course of Alzheimer’s disease—which can now be answered using this new model. Huang, who describes the work as “one of the most challenging and ambitious projects I’ve worked on so far” believes the cell line may also be used to help screen for potential Alzheimer’s disease drugs. 
 

Alzheimer’s is one of the most frightening diseases of our time. Of the top 10 causes of death in the U.S., it is the only disease for which no effective or preventative treatment exists. Recent clinical trial failures have only deepened the pain of patients and their families.

To learn about the state of Alzheimer’s research in the wake of these setbacks—and whether there is hope on the horizon—we caught up with Alzheimer’s expert Jerold Chun, MD, PhD, professor and senior vice president of Neuroscience Drug Discovery at Sanford Burnham Prebys. Chun and his team recently published a Nature study that suggests a potential Alzheimer’s treatment may be closer than we think. 

1. Why has Alzheimer’s disease become so prevalent? Are we better at diagnosing the disease?
   The number of people with Alzheimer’s disease is rising because of the aging Baby Boomers generation—which makes up more than 20% of the U.S. population. As a result, the number of those living with the condition is projected to more than double by 2050 to nearly 14 million people. This will place an incredible economic and social burden on our society—unless a treatment is found.
    
2. Are there any treatments that work for Alzheimer’s disease?
   No disease-modifying therapies exist. The medicines a patient can receive today just treat symptoms. For example, cholinesterase inhibitors and N-methyl D-aspartate antagonists treat cognitive symptoms, such as memory loss, confusion and problems with thinking and reasoning—but they aren’t able to stop the disease. 
    
3. Is it possible to prevent Alzheimer’s?
   Multiple studies from this year’s Alzheimer’s Association International Conference centered on this topic. Evidence suggests that adopting healthy lifestyle choices such as eating a healthy diet, not smoking, exercising regularly and stimulating the mind may decrease the risk of cognitive decline and dementia.

   It is encouraging to know that preventing Alzheimer’s may be partially within our control. However, it is undeniable that even individuals who live a healthy lifestyle will still develop Alzheimer’s. We need to remain laser focused on developing effective preventions and treatments. 
    

4. Do we know the cause of Alzheimer’s? What are the latest theories?
   In short, no. We know that clumps of amyloid-beta and tau proteins in the brain are linked to the disease. We also know that in rare cases genes are involved, because Alzheimer’s can run in families—but this accounts for less than 1% of cases. New research points to unique gene changes within the brain, called somatic gene recombination, as a new potential factor. Some data also implicate aspects of the immune system. It’s most likely that multiple factors lead to disease—and that an effective treatment will tackle Alzheimer’s from several angles. 
    
5. How would you describe the pipeline of Alzheimer’s treatments in development?
   The pipeline of Alzheimer’s treatments is in dire need of expansion. As of February 2019, only 132 drugs were under evaluation in clinical trials. Nearly half of these compounds target beta-amyloid. 

   For comparison, there are nearly 4,000 compounds under development for cancer—which affects almost three times as many Americans each year. We certainly need to continue to invest in cancer treatments—but clearly there is an urgent need to fill the Alzheimer’s pipeline, and an even greater need to find an approach that actually works.
    

6. Tell us more about your research. What did you find? What are the next steps? 
   In school we learned that all cells have the same DNA. However, in our recent research we found that in the brains of patients, the DNA in the Alzheimer’s-linked APP gene can be “mixed and matched” into many different, new forms, some of which aren’t found in healthy individuals. To create these new gene variants, reverse transcriptase—best known as an enzyme infamously used by HIV—is required. This suggests that existing HIV medications—called reverse transcriptase inhibitors—which halt reverse transcriptase, might be useful as a near-term treatment for Alzheimer’s disease. A doctor can prescribe these medicines now as an “off-label” use for the treatment of Alzheimer’s disease. However, prospective clinical trials are needed to test the efficacy and side-effect profiles of these medicines in actual Alzheimer’s disease patients.
    
7. Are humans the only species that get Alzheimer’s disease? 
   To our knowledge, yes. No other animal has the intellectual and cognitive capacity exhibited by humans. For this reason, scientists have developed animal models that exhibit symptoms and pathologies that approximate the disease.
    
8. How far away are we from an effective Alzheimer’s treatment? Years or decades? 
   What excites me about my team’s findings is that, if true, a partially effective treatment may be available now. Reverse transcriptase inhibitors are medicines currently used to treat HIV and hepatitis B, and have been safely used for 30 years with millions of patient-years of experience. New medicines based on this approach could lead to next-generation drugs with better efficacy and safety.

   Other agents in the Alzheimer’s pipeline currently in development are many years away from an effective treatment. And, it could take an additional 30 years for such agents to have the same level of proven safety as reverse transcriptase inhibitors. Nevertheless, new therapeutics must be pursued. Hopefully, our adult children will have great medical options in their future.
    

9. What is the biggest hurdle to developing an Alzheimer’s treatment? 
   A major hurdle is securing funding for early, innovative research. The National Institutes of Health (NIH) is granting more funding than ever before to tackle this disease. However, many people aren’t aware that the NIH overwhelmingly finances projects that are scientifically conservative, which in the case of Alzheimer’s disease has failed to produce effective medicines. Funding that enables scientists to explore new, bold frontiers can be transformational in leading to important advances. This is an area where philanthropic donations can have a major impact—especially now, as the field strives to “think outside of the amyloid box” and explore new approaches.
    
10.  Are you hopeful for the future? Why or why not?
    I am absolutely hopeful for the future. Advances in fundamental brain science will lead to new treatments for Alzheimer’s disease. Our work will hopefully be a start to a world where our children don’t have to live in fear of this disease.

About Jerold Chun 
Jerold Chun, MD, PhD, is a world-renowned neuroscientist who seeks to understand the brain and its diseases. His research has discovered genomic mosaicism and somatic gene recombination, surprising phenomena whereby cells in the brain actually have different genomic DNA sequences that can change with disease states. Chun’s research continues to shed light on Alzheimer’s disease, Parkinson’s disease, multiple sclerosis and other neurodegenerative diseases as well as neuropsychiatric disorders and substance abuse.