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Build muscle and stay young

Researchers have discovered that the skeletal muscle composition of the blind rat is preserved throughout its life, delaying its aging

What is the secret of the blind rat's health? How does he live longer and not suffer from diseases related to aging? It is a rodent that lives most of its life in closed burrows underground, can dig up to 800 kg of soil per year and feeds on a variety of plants and roots.

Dr. Irena Manov from the Institute of Evolution and Dr. Emad Shams from the Laboratory for the Study of Stress Resistance in Mammals at the University of Haifa are studying the blind rat. They became interested in it due to its resistance to underground conditions, especially lack of oxygen. Their studies showed that the rat lives unusually long: it survives seven times as expected based on its body mass (in mammals there is a correlation between body mass and life expectancy). That is, he lives up to 20 years instead of two or three years like mice or rats. In addition, the researchers found that the rat is resistant to cancer (it did not develop a cancerous tumor despite the exposure to carcinogens). From this they hypothesized that the resistance to lack of oxygen (hypoxia) probably contributes to the resistance to cancer and the longevity of the rat.

In another study, the researchers sought to understand what happens in the cells of the rat as it ages. In aging humans, the body's cells begin to secrete proteins that promote inflammation, and this inflammatory environment is the basis for the development of diseases related to aging such as cancer, sarcopenia (muscle wasting), degenerative diseases such as Alzheimer's and diabetes. Therefore, the researchers examined fibroblast cells (fibrous cells in the connective tissue) of the rat, and discovered that they age but hardly secrete inflammatory proteins that are characteristic of other species. Following this study, we examined the skeletal muscles of an old rat, and found in them a low expression of genes that promote inflammation.

Fast/"athletic" muscle fibers (marked in red) and slow muscle fibers (marked in green) in rats and mice

In a study by Prof. Aharon Avivi and his partners from the Institute of Evolution at the University of Haifa, published in the journal Acta Histochemica in 2009, it was found through histochemical staining that the trapezius muscles of the rat are mainly composed of "athletic" fast muscle fibers, but the subject has not been investigated since then. "The data on the special aging processes of the rat and the findings on the composition of its muscles raised the idea that it developed protective mechanisms against sarcopenia and maintaining the function of the skeletal muscles throughout its life. This may explain how he is active (digger) until the age of 20-17 and does not show signs of old age (slowness and hunchback)", explains Prof. Manov.

Fast/"athletic" muscle fibers (marked in red) and slow muscle fibers (marked in green) in rats and mice
Fast/"athletic" muscle fibers (marked in red) and slow muscle fibers (marked in green) in rats and mice

Following these discoveries, the researchers decided to delve into the way in which the rat protects itself from sarcopenia. In one of their latest studies, which won a grant from the National Science Foundation, the scientists examined muscle tissues of young (up to the age of five) and old (12 plus) rats and discovered that most of them indeed consist of fast-twitch fibers. That is, that the muscle composition of the rat is preserved throughout life. This is in contrast to other mammals in which the fast muscle fibers are replaced by slow fibers with age. This time they used immunofluorescence methods, in which artificial antibodies color the fibers according to their types.

In addition, the researchers examined the muscle tissues using molecular methods and discovered a low expression of the genes related to the inflammatory response and a high expression of genes related to stem cells, even in the young rats and even more so in the old. These are pluripotent stem cells, which can differentiate into any cell in the body (including muscle cells) and thus contribute to organ regeneration and healing. In humans and other mammals their amount decreases with age.

Soon the researchers hope to discover the biological mechanisms behind these phenomena. In addition, using a device that measures muscle contractions (received from the Canadian research and development company Aurora Scientific Inc and with the support of the National Science Foundation), they will examine the muscle function of the rat and rats throughout their lives.

Life itself:

Dr. Irena Manov, married + two children (44, 23), lives in Haifa. In her spare time, she tries to help her children ("I like to cook for my daughter who is busy studying finance and accounting") and spend time with her grandchildren ("This year, in honor of my grandson's Bar Mitzvah, I took him to London and fulfilled his dream: we watched a football match at Wembley Stadium").

Dr. Emad Shams, married + three children (15, 9, 7), lives in Majdal Shams ("My quality time with myself is during trips from home to work. During these hours I try to think strategically, plan things, and not just react") . In his spare time, he is involved in agriculture ("I try to go back a little to the roots, to the previous generation, and also scientifically understand the world of plants").

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