Danish scientists observed the twin experiments and found that 25% came from genetic factors and 75% came from environmental factors. What is the principle of aging? Oxygen-free radical theory: Oxygen free radicals are generated in the metabolic process, causing cell damage and leading to senescence. Telomere loss theory: Telomere loss leads to senescence, telomere shortening, or disappearing leads to chromosome instability, resulting in damage to DNA damage. Cumulative theory: cell replication Mistakes are produced in the process. Cellular aging theory: Ageing makes it impossible to identify senescent cells, and do not grow or divide. Gene regulation theory: What is inherited is what all theories say that aging is inevitable, but aging is workable.
There are currently two aging theories: 1 from the perspective of genetic programming and 2 from the perspective of genetic wear. Both theories have relevant supporting evidence
Theory 1: Genetic programming perspective
1. DNA fragments DAF-2 and DAF-16: are life-span regulators. Studies have shown that the DAF-16 gene is related to lifespan and immunity. When DAF-16 is inhibited, it will age. Sugar can inhibit the activity of DAF-16. To delay aging, sugar intake must be reduced.
2. GSTP1 antioxidant gene locus, STXBP5L gene photoaging gene locus, CTC1 protein telomere gene locus, AGER gene encoding glycosylation gene locus 3. Longevity gene SIR2 (German experiment), longevity gene FOXO3A (German experiment) ), longevity gene Cisd2 (Taiwan experiment)
Theory 2: The angle of genetic wear
1. Free radicals: free radicals (ROS) are generated during DNA replication. These free radicals can cause damage to mitochondrial DNA. It will cause damage to the organs that need mitochondria to provide energy. Can cause aging, cancer, etc. Smoking, sun exposure, fried food, salad oil, pollution, pesticides, and even exercise can produce free radicals. Polyphenols, astaxanthin, grape seeds, vitamins A, E, C, etc. can scavenge free radicals. But recent studies also show that free radicals may not be the cause of aging. But, excessive free radicals will cause damage to the body.
2. Telomere perspective: There are meaningless but protective DNA sequences at both ends of human genes, which are called DNA telomeres. Genes are worn out for various reasons during the process of copying. When the telomeres are worn out, the meaningful sequence of DNA will be damaged. Telomeres become shorter with age, so telomeres are considered a biomarker of aging. Studies have found that sedentary people have shorter telomeres. But, people who over-exercise have more free radicals, which can also cause body wear. But the telomere theory is a hypothesis, and it is not clear whether aging leads to shorter telomeres or shorter telomeres leads to senescence.
3. From the perspective of photo-aging: research and mark the UVA and UVB in the ultraviolet rays to damage the skin structure, leading to loss of collagen, sagging skin, wrinkles, sunburn, etc. But not being exposed to the sun at all can cause calcium loss. 4. Anti-glycation angle: The combination of sugar and protein causes the protein to become yellow and brittle, which is caused by skin oxidation. Generate AGEs. This glycation reaction is irreversible, the skin elasticity decreases, the skin becomes loose, wrinkles are formed, and the skin falls into repeated inflammation. Nicotinamide adenine dinucleotide (NAD), now available as a drug, can reverse aging, but its authenticity remains to be verified
The mechanism of delaying aging?
Tumor suppressor gene TP53: When a cell is stressed, it will activate the expression of this gene, thereby inducing cell arrest and death, and regulating cell metabolism. Humans have only one, and elephants have more than 20. If this gene sheet in humans mutates, the possibility of cancer will be increased. Elephants live far healthier than humans and rarely have cancer.
Hyaluronic acid: high molecular weight hyaluronic acid, has a significant inhibitory effect on abnormal cell expansion and prevents excessive growth. It was found from naked mole rats. Normal house mice can only live to 1-3 years, and he can live to 30-40 years old. Even when exposed to carcinogens, they will not get cancer. The cells of naked mole rats are rich in this. This kind of hyaluronic acid is five times that of humans.
DAF-2\DAF-16 gene: IGF point mutation, when the DAF-2 gene is inhibited, people live longer. When DAF-16 is active, people are more energetic, and sugar will inhibit the expression of DAF-16, so abstaining from sugar has great benefits to the body. This experiment verified that gene regulation can prolong lifespan and that mutations in a single gene can prolong lifespan twice. The long-lived elderly will also have this mutation.
Dietary restriction: Google joins the fifth group of aging research, the company name Calico, is doing a lot of anti-aging research, stem cell therapy, and restoring telomerase activity every year. Among them, the ape experiment has been followed for 20 years. The monkeys who eat less than the monkeys who eat more have a far healthier body, skin, and hair. The theory holds in different species. The reason for this success is that restricting diet can inhibit the action of a molecular protein. The molecule is called mTOR, which can control cell growth and metabolism, reduce cell metabolism, and induce a mechanism for removing garbage inside cells, removing unwanted proteins, etc. The waste is removed in time.
Rapamycin: It is extracted from bacteria on Easter Island and can inhibit the effect of mTOR. It is used in anti-rejection therapy for kidney transplantation. In 2009, a study funded by the National Institute of Geriatrics in the United States showed that rapamycin can extend the life span of mice, especially its greatest life span can be extended by 60%. At the same time, it is also being studied for the treatment of cancer and other diseases. But the side effect is to reduce the body's immunity.
Metformin: The most potential to become the next most powerful antioxidant ingredient. The typical drugs for the treatment of type 2 diabetes become longer and healthier after use. The FDA has approved metformin as an anti-aging drug for clinical trials. Clinical trials on whether metformin has anti-aging effects in humans are expected to start in the United States in the winter of 2016. But the side effects are intestinal discomfort and lactic acidosis.
Cutting-edge anti-aging experiment?
Exchange blood experiment: Scientists hypothesize that young individuals have young factors and that aging mice and young mice share blood. The old mice's physical skills have improved, including the brain, muscle, and heart functions. But ethics is very controversial.
Intestinal flora transplantation experiment: Intestinal flora plays an important role in humans. The poop of young fish can make old fish younger.
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