For a long time, human aging has been depicted as a slow and smooth gradual process. However, a recent study, through an in-depth analysis of the proteome of multiple human organs, has overturned this traditional concept. The study results show that the human aging process is a series of gradual stage transitions, with a key "acceleration point" appearing around the age of 50. More importantly, this study points the finger at our vascular system, suggesting it may be the "mastermind" driving systemic aging.
The research, published on July 25th in the top academic journal Cell, provides a new, high-resolution molecular roadmap for understanding aging. It not only confirms the possible biological basis behind the saying "after middle age, everything becomes difficult," but also points to new directions for future development of measures to delay aging and promote healthy longevity.
The Symphony of Purification: Asynchronous Aging of Organs
If the human body is compared to a wonderful symphony orchestra, then the elderly are like different instrument groups (organs) starting to experience synchronization allergies. To accurately capture this process, a team led by Liu Guanghui, an expert in regenerative medicine research from the Chinese Academy of Sciences, conducted local analyses. They collected tissue samples from donors aged from 14 to 68 years old, covering eight major systems of the human body, including the cardiovascular, immune, and digestive systems.
By quantitatively analyzing each protein in the samples, researchers were able to draw a dynamic, life-span-wide organ aging map. The study found that although there is an overall aging trend, the "aging clocks" of different organs are not synchronized. Researchers identified 48 proteins associated with diseases, whose expression levels significantly increase with age. Preset alarm signals appear around the age of 30 — the function changes of this organ responsible for multiple key sleep functions may be an early prelude to the human aging process. Michael Snyder, dean of the School of Medicine at Stanford University in California, believes that this finding is highly consistent with previous studies, once again confirming that "with age, the regulation of hair growth and metabolism undergoes the most profound changes."
Messages of Accelerated Development?
The most eye-catching discovery in the recent study focuses on the period between 45 and 55 years old. During this time, the protein levels in the human body undergo an exciting "tsunami-like" change, leading to a critical turning point. And the coronary artery's center seems to be the aorta — all the arteries of the human body. Data show that the aorta is one of the fastest aging organs among the studied tissues.
This discovery raises an exciting imagination: is the vascular system not only a victim of activation, but also an "messenger" responsible for delivering the signal molecules that validate accelerated activation throughout the body? To this end, the research team isolated a protein that is highly expressed in the aortas of activated individuals and injected it into young activated cells. The results were surprising — these activated cells showed a significant acceleration of activation in the heart. It is speculated that blood vessels act like a complex "pipeline system," and as they themselves age, they start pumping "pro-aging" molecules throughout the body, thereby coordinating and accelerating the aging process of other organs. Snyder said, "We are like car reviews; some parts wear out faster than others." Understanding which parts are vulnerable, especially those that may affect the whole system, is crucial for developing emergency measures to delay aging.
Seeking the "Trigger Point": Public Opinion and Debates in the Scientific Community
Although this study marks around the age of 50 as a key turning point for aging, the scientific community remains cautious. Dr. Maja Olecka from the Leibniz Institute on Aging in Jena, Germany, pointed out that although age-related stage changes do exist, determining a universally applicable exact time for this "turning point" requires larger-scale studies.
In fact, different studies have reached different conclusions. For example, the Snyder team's study last year found that the diabetes turning point occurs between 44 and 60 years old. Other studies have found another diabetes acceleration phase around 80 years old, which is beyond the age range of this study. Liu Guanghui added that, with the accumulation of data in the future, the key molecules found in different studies may gradually converge.
Regardless of when the precise "trigger point" occurs, this study has sparked an important shift in the paradigm of aging research: from the past simple comparison of two states, "young" and "old," to a detailed dynamic time series diagram that spans the entire life course. Olecka said, "Currently, we still don't know what triggers these turning points. This is a very interesting emerging field." Solving these mysteries will help us fundamentally understand aging and ultimately find effective ways to extend the "healthy lifestyle" of humans.
Original: https://www.toutiao.com/article/7531670711602938368/
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