- About 55 million people globally have Alzheimer’s disease and other dementias.
- As scientists expect that number to continue to grow each year, there has been much focus on developing new treatments for the condition.
- Researchers from UC San Diego School of Medicine have found a hematopoietic stem cell transplant can protect against memory loss, neuroinflammation, and beta-amyloid build-up in an Alzheimer’s mouse model.
In the latest research, a team from UC San Diego School of Medicine has found a specific type of stem cell transplant can protect against memory loss,
This study was recently published in the journal
In the most basic terms, stem cells are special cells with the ability to become whatever type of cell the body needs them to be. They can also be used by the body to make repairs, such as repairing tissue damage.
Because of their unique properties, healthy stem cells from either a person’s own body or a donor can be transplanted to help treat certain diseases. Currently, stem cell transplants are used to help treat:
There is also currently a wide variety of research being conducted on other diseases a stem cell transplant may be able to help, including
According to Dr. Stephanie Cherqui, professor of pediatrics in the Division of Genetics at UC San Diego School of Medicine and senior author of this study, the researchers decided to study how hematopoietic stem cells might help in the treatment of Alzheimer’s disease because previous research showed that hematopoietic stem cells could differentiate into
“Microglia are activated and inflammatory in Alzheimer’s disease,” she explained to Medical News Today.
“When microglia are activated, they can lead to
neurodegenerationby destroying the neurons. Thus, we hypothesized that transplanting healthy hematopoietic stem cells may provide healthy microglia in the brain and prevent neuroinflammation and therefore prevent neurodegeneration.”
– Dr. Stephanie Cherqui
For this study, Dr. Cherqui and her team used a mouse model of Alzheimer’s disease to test their theory.
The scientists transplanted healthy hematopoietic stem cells into mice with Alzheimer’s disease.
“We are using hematopoietic stem cells, which are bone marrow stem cells that give rise to blood and immune cells,” Dr. Cherqui detailed.
“To transplant new hematopoietic stem cells, we have to remove the host bone marrow stem cells by
Upon analysis, researchers found that both memory loss and neurocognitive impairment were entirely prevented in Alzheimer’s mouse models receiving a stem cell transplant.
Those mice also exhibited improved object recognition and risk perception, as well as normal
“We were expecting to see a beneficial effect of the stem cell transplant but we were surprised by the dramatic impact with complete rescue of the neurocognitive function and complete prevention of the neuroinflammation,” Dr. Cherqui said.
The scientists then took a closer look at the brains of the Alzheimer’s mouse models treated with stem cells. They found that those mice had a significant reduction of beta-amyloid plaques in the hippocampus and
“Beta-amyloid accumulation also eventually leads to neurodegeneration in Alzheimer’s disease so it is important to observe a reduction of this toxic material in the brain,” Dr. Cherqui said. “However, I believe that the main impact of the stem cell transplant that explain the full rescue of the phenotype is the prevention of microglia activation and neuroinflammation.”
Additionally, the stem cell transplant reduced microgliosis and neuroinflammation and helped keep the blood-brain barrier healthy.
After reviewing this study, Dr. Karen D. Sullivan, a board-certified neuropsychologist and owner of I CARE FOR YOUR BRAIN of Pinehurst, NC, not involved in the research told Medical News Today her first reaction was one of hope.
“Although this is just a first step as a proof-of-concept study and being done in a mouse model, the science is solid and the results are promising especially as they reported both structural and functional brain changes,” she explained.
“As the authors state, Alzheimer’s disease is very complex with multiple disease pathways implicated, but I am optimistic that this work will grow in significance once it is tested in higher-order animals,” Dr. Sullivan added.
Dr. Santosh Kesari, a neurologist at Providence Saint John’s Health Center in Santa Monica, CA, and regional medical director for the Research Clinical Institute of Providence Southern California, also not involved in the study, talked to MNT about the significance of the reduction in beta-amyloid plaques.
“Beta-amyloid is one of the problems that is linked to Alzheimer’s,” he explained. “There’s [a] build-up of this plaque and the brain can’t clear it, or the microglia and other cells in the brain cannot clear this plaque that builds up and that creates more inflammation. And so the microglia trying to clear up the plaque are becoming inflamed and that causes more damage than the plaque itself.”
“So the fact that the transplant reduces the plaque burden, as well as inflammation, means that it improves neurological function in these mice,” Dr. Kesari continued.
“It really strengthened the relationship [between] inflammation and its role in dementia and many other neurological disorders. Inflammation is an underlying issue that continues to create problems over time, even in
stroke, multiple sclerosis, ALS, and other diseases. It’s the inflammation that’s creating as much problem as the initial cause of the problem.”
– Dr. Santosh Kesari