A New Hope for Healthy Aging
Scientists at the Icahn School of Medicine at Mount Sinai have made a groundbreaking discovery, reversing the aging process in blood-forming stem cells in mice.
This breakthrough, published in Cell Stem Cell, offers new hope for treating age-related blood disorders and potentially even slowing the overall aging process. The key to this discovery lies in a tiny organelle within our cells: the lysosome.
The Cell’s Recycling Center
Think of the lysosome as the cell’s recycling and waste disposal system. These small but mighty structures break down and reuse cellular waste, playing a vital role in a cell’s metabolism.
The Mount Sinai study focused on a specific type of cell: hematopoietic stem cells (HSCs). These are the master cells in our bone marrow that create all other blood and immune cells.
The Problem with Aging Stem Cells
The research team, led by Dr. Saghi Ghaffari, found that as HSCs age, their lysosomes start to malfunction. They become overly acidic, damaged, and work in overdrive.
This lysosomal dysfunction disrupts the stem cells’ ability to function correctly, leading to a decline in the production of healthy blood and immune cells.
This is a major factor in the increased risk of cancer and other diseases as we get older. In fact, the median age for a cancer diagnosis is 67, according to the National Cancer Institute [1].
| Feature | Aged Stem Cells | Rejuvenated Stem Cells |
|---|---|---|
| Lysosomal State | Hyper-acidic, damaged, hyperactive | Integrity restored |
| Regenerative Potential | Decreased | Increased over 8-fold |
| Blood Cell Production | Imbalanced | Balanced and healthy |
| Inflammation | Increased | Reduced |
A Return to Youth
The Mount Sinai scientists discovered that by using a specific inhibitor to slow down the hyperactive lysosomes, they could reverse the signs of aging in the stem cells.
The once-old and dysfunctional stem cells began to act young and healthy again. They regained their ability to regenerate, produce balanced blood cells, and their metabolism and mitochondrial function were renewed.
“Our findings reveal that aging in blood stem cells is not an irreversible fate. Old blood stem cells have the capacity to revert to a youthful state; they can bounce back,” said Dr. Ghaffari [1].
What This Means for the Future
This research opens up exciting new possibilities for the future of medicine. By targeting lysosomal dysfunction, we may be able to:
- Maintain healthy blood and immune systems in the elderly.
- Improve the success of stem cell transplantations.
- Reduce the risk of age-related blood disorders.
- Potentially impact the overall aging process.
Dr. Ghaffari’s team is now investigating the link between lysosomal dysfunction in old stem cells and the development of leukemia, which could further revolutionize our understanding of cancer.
The Research Team
The study was led by Dr. Saghi Ghaffari, MD, PhD, a Professor of Cell, Developmental, and Regenerative Biology at the Icahn School of Medicine at Mount Sinai and a member of the Black Family Stem Cell Institute.
References
[1] Mount Sinai Newsroom. “Mount Sinai Scientists Reverse Aging in Blood Stem Cells by Targeting Lysosomal Dysfunction.” https://www.mountsinai.org/about/newsroom/2025/mount-sinai-scientists-reverse-aging-in-blood-stem-cells-by-targeting-lysosomal-dysfunction
