Researchers from the Department of Genetics and Medical Genetics at the University of Wisconsin in the United States and the University of Tokyo in Japan have discovered a key enzyme that can prevent cell aging. This is helpful to explain many of the phenomena that cause human aging, and can also help researchers develop Anti-aging drugs. The research results were published in Cell magazine.
As early as the 1930s, the American scientist Mckay discovered that restricting feeding to rats can extend their lifespan. Subsequent studies have shown that this life extension effect has nothing to do with the composition of the food, but with the calorie (calorie) content of the food, so this phenomenon is called "calorie restriction" or "diet restriction".
Later, MIT Lenny Guarente and colleagues used yeast for aging research. They found that the Sir2 gene in yeast has an important role in regulating aging. Not only that, Sir2 can also be activated by calorie restriction, thereby mediating calorie restriction Aging effect. Higher organisms have 7 Sirtuin genes (Sirt1-7) similar to Sir2. Among them, the protein products of Sirt1, Sirt6 and Sirt7 exist in the nucleus, the protein encoded by Sirt2 is usually in the cytoplasm, and the products of Sirt3, Sirt4 and Sirt5 Mitochondria. Sir2 and its related proteins have nicotinamide adenine dinucleotide (NAD +)-dependent histone deacetyltransferase activity.
In this latest article, the researchers discovered another important Sirtuin gene: the important role of Sirt3 expressed enzymes. This is the first time that clear evidence has been obtained to confirm the anti-aging effect of Sirtuin in mammals. The researchers found that this enzyme has an effect on mitochondria-under low-calorie conditions, Sirt3 enzyme levels increase, by affecting the mitochondria to change the metabolism and reduce the generation of oxygen free radicals. We all know that free radicals can damage cells, accelerate aging, cause the skin to thicken, wrinkle, sag, and joints will become more and more stiff. Therefore, researchers believe that Sirt3 is an important anti-aging element.
Some activities, such as smoking, eating fried foods, bacterial infections, and excessive stress will produce excessive free radicals. Eating green leafy vegetables and whole wheat bread rich in antioxidants can neutralize free radicals and reduce freedom. Base injury.
In addition, various members of the Sirtuin family have important metabolic regulatory functions, such as Sirt1 by modifying the substrates PGC-1α, FOXO1, transcription signal transducer and activator (STAT) 3 and CREB regulated transcription coactivator (CRTC) 2 Regulating the production of liver glucose can also regulate the balance of cholesterol and fat metabolism through the liver X receptor (LXR). In addition, Sirt1 can also regulate liver function by activating adenosine phosphate activated protein kinase (AMPK).
Sirtuin gene expression and activity are affected by dietary intake, ambient temperature, circadian rhythm, and oxidative stress. In addition, Sirtuin can remove the acetylation groups of various substrate proteins, thereby regulating the function of its substrate proteins. Only Sirt1 substrate protein has been found so far more than 40, including tumor suppressor gene p53, forkhead transcription factor (FOXO), nuclear factor (NF) κB and co-activator 1α (PGC-1α).
