Alzheimer’s is a progressive disease that destroys memory and other important mental functions. According to the non-profit HFC, co-founded by CIRM Board member Lauren Miller Rogen and her husband Seth Rogen, more than 5 million Americans are living with Alzheimer’s. It is the 6th leading cause of death in the U.S and it is estimated that by 2050 as many as 16 million Americans will have the disease. Alzheimer’s is the only cause of death among the top 10 in the U.S. without a way to prevent, cure, or even slow its progression, which is it is crucial to better understand the disease and to develop and test potential treatments.

It is precisely for this reason that researchers led by Yanhong Shi, Ph.D. at City of Hope have developed a ‘mini-brain’ model using stem cells in order to study Alzheimer’s and to test drugs in development.

The team was able to model sporadic Alzheimer’s, the most common form of the disease, by using human induced pluripotent stem cells (iPSCs), a kind of stem cell that can be created from skin or blood cells of people through reprogramming and has the ability to turn into virtually any other kind of cell. The researchers used these iPSCs to create ‘mini-brains’, also known as brain organoids, which are 3D models that can be used to analyze certain features of the human brain. Although they are far from perfect replicas, they can be used to study physical structure and other characteristics.

The scientists exposed the ‘mini-brains’ to serum that mimics age-associated blood-brain barrier (BBB) breakdown. The BBB is a protective barrier that surrounds the brain and its breakdown has been associated with Alzheimer’s and other age-related neurodegenerative diseases . After exposure, the team tested the ‘mini-brains’ for various Alzheimer’s biomarkers. These markers included elevated levels of proteins known as amyloid and tau that are associated with the disease and synaptic breaks linked to cognitive decline.

Research using brain organoids has shown that exposure to serum from blood could induce multiple Alzheimer’s symptoms. This suggests that combination therapies targeting multiple areas would be more effective than single-target therapies currently in development.

The team found that attempting a single therapy, such as inhibiting only amyloid or tau proteins, did not reduce the levels of tau or amyloid, respectively. These findings suggest that amyloid and tau likely cause disease progression independently. Furthermore, exposure to serum from blood, which mimics BBB breakdown, could cause breaks in synaptic connections that help brains remember things and function properly.

“Dear CIRM,

“World Sickle Cell Day is this Saturday June 19^th. The goal of this day is to increase knowledge of the disease and understanding of the challenges faced.

“It is a day that I greet with very mixed feelings.  I’m of course extremely grateful to CIRM for the time and money spent looking for a cure.  The work of doctors, of researchers, the courage of families in the sickle cell community who are taking part in studies, and of course those of you who worked so hard for the original funding for CIRM, I applaud all of you, yet it’s hard to wait for a cure.

“While I wait I worry. I worry about my friends who are not getting good care.  They are the ones who can’t find a doctor to treat them, not able to take advantage of the medications that are already approved.  They are the ones who walk into the Emergency Room hoping for knowledgeable treatment while understanding that they may be accused of being a drug seeker,  turned away in excruciating pain. They are the ones who succumb after years of poor care.

“With sickle cell disease there is the same level of understanding about medical malpractice that we had of police brutality before George Floyd. We hardly remember Rodney King or Eric Garner. As a country we were aware that something was wrong but we tended to retreat in denial after each terrible headline.

“That’s where we are with sickle cell disease.  We may see a heart-wrenching story and watch televised reports with interest, but after all, it’s easier to live in disbelief, to think that medical care is not that bad, rather than understand that people are being dismissed and denied treatment. We call it structural racism without understanding what that term really means.

“While I wait I must acknowledge that change is coming.  We have a Sickle Cell Data Collection Project in California that helps us track healthcare for sickle cell disease. This is data that we can use to point to structural weakness and address health disparities.  NASEM, the National Academies of Science Engineering and Medicine, has published a huge report with significant suggestions for improving sickle cell care. Many scientists, researchers and advocates took part in this landmark study, detailing what has gone wrong in health care and how to improve the work. And of course we have CIRM. I am very thankful for the leadership and pioneering work of doctors Donald Kohn, Matthew Porteus and Joseph Rosenthal who are using their knowledge and experience in this fight.

“When we have successful research on stem cell transplants for sickle cell disease, many of us with sickle cell family members will want to relax, but we can’t forget those who may not be able to get a curative transplant. I hope Dr Niihara at Emmaus, and Dr. Love of Global Blood Therapeutics will continue their important work finding effective treatments. We must continue this fight on all fronts.

“World Sickle Cell Day will come again next year.  Let’s see what it brings.

“A sickle cell grandmother, “Nancy M. René.”