“Senescent cells release a senescence-associated secretory phenotype (SASP), including exosomes that may act as signal transducers between distal tissues, and propagate secondary senescence.”
As the global population grows older, understanding what drives the aging process is becoming increasingly important. Diseases like Alzheimer’s, cardiovascular conditions, and cancer are more common with age, yet many current treatments only manage symptoms rather than addressing the underlying biological causes.
One contributor to aging is the buildup of “senescent” cells—cells that have stopped dividing but do not die. These cells can harm nearby tissues by releasing molecular signals, a process known as secondary senescence.
Scientists have found that senescent cells release tiny particles called exosomes. A research team from The Buck Institute for Research on Aging recently discovered that these exosomes carry aging-related messages through the bloodstream. Their study, titled “Exosomes released from senescent cells and circulatory exosomes isolated from human plasma reveal aging-associated proteomic and lipid signatures,” was featured as the cover article in Aging (Aging-US), Volume 17, Issue 8.
The Study: Exosomes and Aging
The team led by Sandip Kumar Patel, Joanna Bons, and Birgit Schilling from The Buck Institute for Research on Aging focused their study on exosomes—tiny, bubble-like structures released by cells that carry proteins, lipids, and genetic material. These particles can move through the bloodstream and influence distant tissues.
The researchers wanted to know whether exosomes from senescent cells and from the blood of older adults shared common markers of aging. Since aging cells are spread throughout the body and lack a single clear marker, exosomes could provide a new way to detect their presence through a simple blood test.
To explore this, the team analyzed exosomes from two sources: lab-grown human lung cells that had undergone senescence and blood samples from both young (20–26 years old) and older (65–74 years old) adults. They used high-throughput mass spectrometry.
Results: Exosomes Reveal Signs of Aging
In total, the team identified over 1,300 proteins and 247 lipids within the exosomes. Specifically, 52 proteins appeared in both senescent cells and the blood plasma of older adults, many of which are associated with inflammation and tissue damage. Some examples include Prothrombin, Plasminogen, and Reelin—molecules involved in blood clotting, tissue remodeling, and neural development. Their presence in both aged blood and senescent cells suggest a broader impact of aging on multiple biological systems.
The team also observed significant changes in the lipid content of the exosomes. Lipids that help maintain cell membrane structure were more common in samples from older individuals, while lipids involved in energy storage were less abundant.
In addition, the researchers detected changes in microRNAs—small pieces of genetic material that regulate gene expression. Several microRNAs found in the blood of older adults have already been associated with diseases such as Alzheimer’s and osteoarthritis.
The Impact: Potential for Diagnostics and Anti-Aging Therapies
This study is among the first to directly compare exosomes from senescent cells and human plasma, revealing shared aging-related markers across biological systems.
These particles act like messengers, spreading signals that may accelerate aging in other cells. This supports the concept of secondary senescence—where aging-like behavior is transmitted from senescent cells to healthy ones—suggesting that exosomes may help propagate aging throughout tissues over time.
This work could lead to the development of blood tests that measure biological age more accurately than a person’s chronological age. It might also help clinicians monitor the effectiveness of anti-aging treatments.
Future Perspectives and Conclusion
Although the study involved a small number of human samples, it presents a promising new approach to studying aging. If confirmed in larger studies, the findings could lead to improved diagnostic tools and therapies for age-related diseases.
In the long term, researchers may explore ways to block or modify harmful exosome signals to protect healthy cells from premature aging. These molecular signatures could also support personalized medicine approaches or help track the effectiveness of anti-aging interventions in clinical settings.
Click here to read the full research paper published in Aging (Aging-US).
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