A team of researchers from the University of Geneva (Switzerland) analyzed the changes in gene expression simultaneously in various organs of mice after variations from hot to cold and vice versa. In his work, published in the scientific journal ‘eLife’, he discovered that all organs react strongly to changes in temperature, each showing its own specific modulation.
Human beings, like most organisms, are constantly exposed to colder or warmer temperatures. These environmental variations pthey cause surprising metabolic effects and require constant adaptations. Although some of these adaptations confer certain beneficial health effects, the impact of cold and heat on different organs in a whole-body context was unknown.
Temperature is one of the main environmental factors to which living beings are subjected. Exposure to cold or heat has surprising effects on metabolism and health, and the implication of temperature in human health is also evident from the geographical distribution of the incidence of certain diseases. But, beyond the physiological response of some tissues, What does living in a colder or warmer environment contribute to biological changes throughout the body?
“In our previous studies we had already observed that temperature had important effects on the functioning of certain organs. Now we know that exposure to cold favors weight loss due to increased thermogenesis, and alleviates the symptoms of multiple sclerosis, while exposure to heat has protective effects on certain age-related diseases, like osteoporosis.
But what happens at the level of the entire organism? Indeed, our previous results point to context-dependent effects of temperature alterations on various organs and diseases, but the global adaptation of the organism must be approached in an integrative way”, explains Mirko Trajkovski, the leader of the investigation.
To address this goal, scientists analyzed gene expression in eleven organs (all adipose (fat) tissues, muscle, liver, brain, hypothalamus, ileum, spinal cord, spleen, and bone marrow) from three groups of mice exposed to a temperature of 10°C, 22°C or 34°C.
“The data shows that the whole organism reacts profoundly to changes in temperature. However, there is no uniform answer: each organ changes its gene expression in its own way, somewhat differently from the rest of the fabrics,” says Trajkovski.
To better understand whether this phenomenon was due to the unique expression of organ-specific genes, the research team performed additional analyses, focusing on genes that are expressed in all organs. And even considering only this restricted set of genesthe activation differences were still striking.
“Knowing that exposure to alternate temperatures causes important effects in metabolic diseases such as obesity and osteoporosis, or even in autoimmune diseases, indicates the Use of temperature changes as a possible therapeutic intervention in lifestyle.
However, we first need to unravel the effects induced by temperature in an integrative way throughout the body, and not just at the level of a single organ. Our work allows precisely that: investigate and understand the mechanisms that act on several organs simultaneously”details the researcher.
To accelerate research in this emerging field, the Geneva team created a free and easily accessible web application that allows users, both scientists and the general public, to search for the expression of thousands of genes in response to cold exposure. or to heat in various organs. “These results will be more useful if they are shared and exploited by a large number of people”, Trajkovski concludes.