You thought you knew your age, you only know the date of birth.
The age in the passport is worse and worse describes the real state of a person. 2 people can be born in one year, but to old age to come with a completely different reserve of health: one in 80 years actively uses new technologies, the other gradually loses memory and independence. Therefore, scientists are now trying to measure not the calendar, but biological age.
For this purpose, a biological clock is created. They estimate how old the body has aged at the level of cells and molecules, and not how many years have passed since the date of birth. Such tools already know how to quite accurately associate the state of tissues with the risk of diseases, weakness of the body and the expected life expectancy. The main problem is that many hours work as a complex black box: the result is, but it is difficult to understand which processes inside the body most affected the assessment.
A group of scientists from Harvard and other scientific centers have proposed a new variant of the biological clock, which is easier to interpret. Instead of chemical tags on DNA, the researchers used gene activity. Such data shows which genes are enabled or off at a particular moment. According to this molecular profile, the system predicts biological age in rodents, monkeys and humans, and also assesses how many years of life can stay in humans.
The work was based on more than 11 thousand profiles of gene activity in 4 species. The set includes data from mice, rats, monkeys and humans. The researchers used animal materials with genetic changes, drug and dietary interventions that affect aging and life expectancy. In the human part of the analysis there were more than 4 thousand samples, and monkeys - more than 2600.
Most biological clocks of aging are built using AI and large databases. Some models look at blood proteins associated with brain aging, and better reflect cognitive condition than normal age. Others estimate the metabolic age by protein, fatty acids, and other metabolic molecules. Newer multi-omix clocks combine blood, metabolism, gene activity, and clinical data.
The most famous direction remains the epigenetic clock. With age, DNA accumulates chemical labels that affect the work of genes. These labels change under the influence of nutrition, physical activity, stress, sleep and disease. One of the most famous tools, the Croat watch, uses DNA methylation and shows a break between passport and biological age. This rupture was associated with the risk of various diseases, and later versions of the watch tried to assess the maximum life expectancy. Scientists have also created an epigenetic clock that works in different mammal species.
But epigenetic clocks have a weak point: they do not explain what exactly is happening in the body. Labels on DNA well predict age, but the reasons for age-related methylation changes are not fully clear. Transcriptom clocks, built on gene activity, give more understandable biology. If the model sees that the genes of inflammation are turned on or the work of mitochondria is disrupted, the researcher can associate the assessment of age with specific processes.
A transcript is a complete set of RNA molecules that show which genes are active in the cell or tissue. With age, this profile changes. Previous studies have linked transcriptome aging with chronic inflammation, mitochondria failures and destruction of the extracellular matrix. Mitochondria give cells energy, and the extracellular matrix works as a molecular framework that supports tissues and organs. When these systems break down, the body recovers worse after loads and damage.
Transcriptomet clock also has a minus. Gene activity changes faster than DNA methylation. It is affected by illness, stress, training, inflammation and even the time of day. Therefore, transcript can reflect not only aging, but also the short-term state of the body. The Harvard team tried to bypass this problem due to a large set of data and check the model on different types, tissues and states.
Scientists have built several hours that assessed age and the risk of death by gene activity profiles. Then the models were checked on independent data, which included rodents with accelerated aging, Alzheimer's disease, chronic kidney disease and other age-related disorders. When applied to individual cells, the clock showed an increased transcriptom age of more than 90% of the samples. This suggests that the age signal can be traced not only at the level of the body, but also within individual cells.
In humans, the new watch accurately predicted the life expectancy of participants in a major cardiology study. The model also reacted to factors that change the rate of aging. After radiation or chronic diseases, the biological age increased by the hour. After rejuvenating interventions in animals, including parabiosis, the indicator decreased. With parabiosis, an aging animal receives the blood of a young donor, and in experiments on rodents, such a procedure can partially restore the work of tissues.
Analysis of genes that most influenced the readings of the clock led researchers to familiar aging mechanisms. With age, genes of inflammation, cellular energy failure and senesption were activated. Senessent cells no longer divide normally, but remain in the tissues and secrete molecules that enhance inflammation and damage neighboring cells. Many signals were repeated in different organs and in different species, which indicates the general mechanisms of aging in mammals.
For longevity research, such a tool is especially useful. Most experiments are conducted on rodents because they live much fewer people and show the effect of interventions faster. The new clock allows you to see how the biological age of the animal changes after a medicine, diet or genetic modification, without waiting for natural death. This can speed up the test of potential methods of slowing aging.
But the new clock does not give an unmistakable prediction of the future. Scientists do not yet know whether changes in gene activity are the cause of aging or only following already accumulated damage. The watch can measure the overall health and stability of the body, and not the mechanism of aging in its pure form.
The difference is important. With age, cells include not only harmful programs, but also protective genes that help to cope with stress, inflammation, and damage. Not every age-related change in gene activity needs to be suppressed. Some of these reactions show that the body is trying to resist wear and tear. Transcript gives a picture of the state at a particular moment, so researchers still need to separate genes that accelerate aging from the genes that help protect against it.
There is a broader problem. Biological watches are getting bigger, and different models do not always match. One tool can show that a person is biologically older than his passport age, another will give a softer score. Therefore, any hours of aging should be carefully checked on independent data, different groups of people and understandable clinical indicators.
The new technology is not yet ready for medical offices and personal forecasts. But for laboratories, it gives a more transparent way to look at aging: not just to get a number, but to see which genes and processes the body is pulling the body to an older or younger state.
The age in the passport is worse and worse describes the real state of a person. 2 people can be born in one year, but to old age to come with a completely different reserve of health: one in 80 years actively uses new technologies, the other gradually loses memory and independence. Therefore, scientists are now trying to measure not the calendar, but biological age.
For this purpose, a biological clock is created. They estimate how old the body has aged at the level of cells and molecules, and not how many years have passed since the date of birth. Such tools already know how to quite accurately associate the state of tissues with the risk of diseases, weakness of the body and the expected life expectancy. The main problem is that many hours work as a complex black box: the result is, but it is difficult to understand which processes inside the body most affected the assessment.
A group of scientists from Harvard and other scientific centers have proposed a new variant of the biological clock, which is easier to interpret. Instead of chemical tags on DNA, the researchers used gene activity. Such data shows which genes are enabled or off at a particular moment. According to this molecular profile, the system predicts biological age in rodents, monkeys and humans, and also assesses how many years of life can stay in humans.
The work was based on more than 11 thousand profiles of gene activity in 4 species. The set includes data from mice, rats, monkeys and humans. The researchers used animal materials with genetic changes, drug and dietary interventions that affect aging and life expectancy. In the human part of the analysis there were more than 4 thousand samples, and monkeys - more than 2600.
Most biological clocks of aging are built using AI and large databases. Some models look at blood proteins associated with brain aging, and better reflect cognitive condition than normal age. Others estimate the metabolic age by protein, fatty acids, and other metabolic molecules. Newer multi-omix clocks combine blood, metabolism, gene activity, and clinical data.
The most famous direction remains the epigenetic clock. With age, DNA accumulates chemical labels that affect the work of genes. These labels change under the influence of nutrition, physical activity, stress, sleep and disease. One of the most famous tools, the Croat watch, uses DNA methylation and shows a break between passport and biological age. This rupture was associated with the risk of various diseases, and later versions of the watch tried to assess the maximum life expectancy. Scientists have also created an epigenetic clock that works in different mammal species.
But epigenetic clocks have a weak point: they do not explain what exactly is happening in the body. Labels on DNA well predict age, but the reasons for age-related methylation changes are not fully clear. Transcriptom clocks, built on gene activity, give more understandable biology. If the model sees that the genes of inflammation are turned on or the work of mitochondria is disrupted, the researcher can associate the assessment of age with specific processes.
A transcript is a complete set of RNA molecules that show which genes are active in the cell or tissue. With age, this profile changes. Previous studies have linked transcriptome aging with chronic inflammation, mitochondria failures and destruction of the extracellular matrix. Mitochondria give cells energy, and the extracellular matrix works as a molecular framework that supports tissues and organs. When these systems break down, the body recovers worse after loads and damage.
Transcriptomet clock also has a minus. Gene activity changes faster than DNA methylation. It is affected by illness, stress, training, inflammation and even the time of day. Therefore, transcript can reflect not only aging, but also the short-term state of the body. The Harvard team tried to bypass this problem due to a large set of data and check the model on different types, tissues and states.
Scientists have built several hours that assessed age and the risk of death by gene activity profiles. Then the models were checked on independent data, which included rodents with accelerated aging, Alzheimer's disease, chronic kidney disease and other age-related disorders. When applied to individual cells, the clock showed an increased transcriptom age of more than 90% of the samples. This suggests that the age signal can be traced not only at the level of the body, but also within individual cells.
In humans, the new watch accurately predicted the life expectancy of participants in a major cardiology study. The model also reacted to factors that change the rate of aging. After radiation or chronic diseases, the biological age increased by the hour. After rejuvenating interventions in animals, including parabiosis, the indicator decreased. With parabiosis, an aging animal receives the blood of a young donor, and in experiments on rodents, such a procedure can partially restore the work of tissues.
Analysis of genes that most influenced the readings of the clock led researchers to familiar aging mechanisms. With age, genes of inflammation, cellular energy failure and senesption were activated. Senessent cells no longer divide normally, but remain in the tissues and secrete molecules that enhance inflammation and damage neighboring cells. Many signals were repeated in different organs and in different species, which indicates the general mechanisms of aging in mammals.
For longevity research, such a tool is especially useful. Most experiments are conducted on rodents because they live much fewer people and show the effect of interventions faster. The new clock allows you to see how the biological age of the animal changes after a medicine, diet or genetic modification, without waiting for natural death. This can speed up the test of potential methods of slowing aging.
But the new clock does not give an unmistakable prediction of the future. Scientists do not yet know whether changes in gene activity are the cause of aging or only following already accumulated damage. The watch can measure the overall health and stability of the body, and not the mechanism of aging in its pure form.
The difference is important. With age, cells include not only harmful programs, but also protective genes that help to cope with stress, inflammation, and damage. Not every age-related change in gene activity needs to be suppressed. Some of these reactions show that the body is trying to resist wear and tear. Transcript gives a picture of the state at a particular moment, so researchers still need to separate genes that accelerate aging from the genes that help protect against it.
There is a broader problem. Biological watches are getting bigger, and different models do not always match. One tool can show that a person is biologically older than his passport age, another will give a softer score. Therefore, any hours of aging should be carefully checked on independent data, different groups of people and understandable clinical indicators.
The new technology is not yet ready for medical offices and personal forecasts. But for laboratories, it gives a more transparent way to look at aging: not just to get a number, but to see which genes and processes the body is pulling the body to an older or younger state.
