After 23 years of deciphering the “Book of Life”, can humans finally solve the mystery of aging?

Scientists have long been exploring the mysteries of human evolution, hoping to find a scientific explanation for the mechanism and process of aging. On February 12, 2001, the International Human Genome Consortium, jointly participated by scientists from China, the United States, Britain, France, Germany, and Japan, announced the human genome map and preliminary analysis results .

Although it is only a "sketch", this epoch-making achievement in the field of life sciences has laid an important foundation for deciphering the genetic code of the euchromatin of the human genome, and has also provided necessary data and references for further research in related disciplines and industries such as genomics, genetics and bioinformatics. In the following 23 years, relevant research results have continued to emerge. We can't help but ask, how can drawing a perfect "complete manual" for humans help us study our "birth, aging, illness and death"? How far have we come in the process of solving the mystery of human aging ?

01 "Life" and "Death" in the process of human evolution, does your gene have the final say?

Richard Dawkins, a famous British evolutionary biologist, once expressed the view that life is a survival machine created by genes, and humans are just carriers of genes . In the billions of years of biological evolution on Earth, the reason why humans have been able to surpass other species on Earth and stand at the top of the food chain is due to genetic selection and unlimited replication.

Gene structure refers to the coding sequence of a gene. The coding sequence is called exon, which is the part of a gene expressed as a polypeptide chain; the non-coding sequence is called intron, also known as intervening sequence (IVS). Deoxyribonucleic acid (DNA) is one of the four biological macromolecules contained in biological cells. DNA carries the genetic information necessary for the synthesis of RNA and protein, and is an essential biological macromolecule for the development and normal functioning of organisms. Genes are specific sequences on DNA molecules. They contain the genetic information of organisms and guide the growth, development and function of organisms. Genes control and regulate organisms by encoding proteins, thereby affecting their morphology, behavior and survival strategies. In the history of biological evolution, the selection of genes is achieved through two main mechanisms: natural selection and genetic variation . The former refers to the process in which organisms that adapt to the environment are more likely to survive and reproduce, thereby passing on their beneficial genes to the next generation; the latter refers to the random variation and recombination of genes during replication, which provides genetic diversity for organisms, so that genes that adapt to the environment can be retained and inherited.

To map the human genome is to accurately arrange the approximately 3 billion base pairs of deoxyribonucleic acid (DNA) in human cells into a complete "map", thus revealing the mystery of the "birth" and "death" of human genes during the evolution process.

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According to the analysis of global population data, the maximum life span of human beings is limited, and aging is an inevitable process of life. As time goes by, all aspects of the human body and other organisms will change. These changes include physical decline, sagging skin, decreased vision, memory loss, etc.

Human aging is also closely related to genes. Gene mutations or functional defects can lead to aging or premature aging. With the development of genetics and molecular biology techniques, understanding the changes that occur in this life process will help us understand normal aging and lifespan.

02 What is the connection between genes and aging?

Related, but not completely determined

(1) These genes and regions are related to life span

ApoE gene : ApoE is one of the human apolipoproteins. Apolipoproteins are components of lipoprotein particles, involved in lipoprotein synthesis, secretion, processing and metabolism, and play an important role in blood lipid metabolism. The protein encoded by the ApoE gene is related to cholesterol metabolism and lipid transport. Different ApoE gene variants are closely related to the risk of cardiovascular disease, Alzheimer's disease and other diseases. For example: There are 3 common ApoE alleles, namely e2, e3 and e4, which encode apolipoprotein E subtypes E2, E3 and E4 respectively. Both E2 and E4 are associated with increased plasma triglyceride concentrations. It plays an important role in lipoprotein metabolism. Patients carrying the ApoE E2/E2 genotype are at high risk of early vascular disease, and patients carrying the ApoE E4/E4 genotype are susceptible to atherosclerosis. The ApoEε4 variant is associated with an increased risk of Alzheimer's disease.

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FOXO3 gene : The protein encoded by the FOXO3 gene is related to cell survival and repair. The longevity variant of FOXO3 is associated with extended lifespan and anti-aging characteristics. Studies have shown that people with certain FOXO3 variants may be more likely to achieve longevity.

TERT gene : The enzyme encoded by the TERT gene plays an important role in cell division and DNA repair. TERT mutations are associated with the risk of some cancers and chronic diseases such as heart disease.

Other regions associated with lifespan : In addition to the genes mentioned above, there are many other genes and gene regions that are associated with lifespan. For example, genes or regions such as IL6R and LEPR have also been studied to have a certain relationship with lifespan, usually related to the risk of chronic diseases and inflammatory response.

(2) Other factors

Life expectancy is a complex, multi-factorial issue, and is also affected by a combination of factors including living environment, lifestyle, and diet.

A good living environment is a necessary condition for human survival and health. If humans live in a damaged and polluted environment for a long time, it will cause various diseases, accelerate aging and even death.

Poor eating habits, such as lack of essential nutrients, will prevent the body from obtaining enough nutrients to support normal cell and tissue function, leading to decreased body function. Excessive calorie intake can cause the body to produce oxidative stress, which in turn leads to cell damage and aging.

Bad living habits such as long-term smoking, alcoholism, staying up late, and not liking to exercise will accelerate the aging of the body and cause respiratory, cardiovascular, and digestive system diseases. Long-term stress and depression can cause damage to the body and brain, thereby accelerating aging.

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03 How far have we come in delaying aging?

Maintaining a balanced diet, exercising moderately, and coping with stress and negative emotions correctly have been recognized as important ways to delay aging. Nowadays, gene therapy has also become an emerging method. Scientific studies have shown that epigenetic changes play an important role in the aging process, and strategies targeting epigenetic regulators have great potential in offsetting aging-related decline .

Last year, the international scientific team T2T published six papers in Science stating that the most complete human genome map ever has been completed , filling in the missing "puzzle" pieces for nearly 20 years, and also means that humans are one step closer to conquering cancer and other diseases.

More complete segmental repeat information improves genotyping.

Image source: T2T Alliance

The completion of this latest human genome map marks an important step forward in the scientific community's understanding of the human genome, and also provides a more comprehensive and in-depth foundation for gene therapy and anti-aging research. The completeness and accuracy of the genome map are crucial to understanding the relationship between genes and diseases, as they reveal the impact of gene variation and mutation on health and disease .

Gene therapy is a method of treating or preventing disease by modifying an individual's genes. The idea is to repair or replace defective genes to restore normal physiological functions. The most complete human genome map provides more accurate and comprehensive basic information for gene therapy, allowing scientists to better understand the relationship between disease and genes, and accurately locate and repair defective genes. By targeting specific gene mutations, gene therapy is expected to provide more effective treatments for some genetic diseases.

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On the other hand, the completion of the genome map also provides important support for research on delaying aging. By studying the genes related to aging in the genome map, scientists can have a deeper understanding of the molecular mechanisms of aging and find potential targets and therapeutic pathways for delaying aging . This breakthrough provides researchers with more in-depth and comprehensive genetic information.

Older people are more susceptible to many chronic diseases, such as heart disease, cancer, and Alzheimer's disease. If more efficient and precise treatments and strategies can be found, it will bring new progress in treating or delaying the onset of chronic diseases caused by aging. However, gene therapy is a complex and sophisticated biomedical technology that still faces many challenges and limitations, and the safety and effectiveness of the technology need to be further verified . Scientists are working hard to research and develop new drugs, treatments, and interventions to slow the aging process. With the continuous advancement of science and technology and the deepening of research, I believe that humans may be able to find effective ways to delay aging and provide new possibilities for extending human life.

author:

Liu Youshuo, Director of the Institute of Aging and Geriatric Diseases, Central South University, Head of the Geriatrics Department of Xiangya Second Hospital, National First-Class Chief Physician

Li Nannan is a second-level researcher at the Hunan Association for Science and Technology and a director of the Hunan Science Writers Association.

Reviewer: Chen Yuefei, Researcher, Member of Hunan Science Writers Association

Produced by: Science Popularization China

Produced by: China Science and Technology Press Co., Ltd., China Science and Technology Publishing House (Beijing) Digital Media Co., Ltd.