Paolo Sassone-Corsi The influence of circadian rhythms on gene expression and metabolism
Paolo Sassone-Corsi, Director of the Center for Epigenetics and Metabolism at the University of California until 2020
- 1997 • Liliane Bettencourt Prize for Life Sciences
Paolo Sassone-Corsi set himself the mission to understand the effects of the Earth’s rotation, and thus the alternation between day and night, on living organisms. Through his research, he discovered that every cell beats to the rhythm of a circadian biological clock.
The biological clock and circadian rhythm
Which Earthly phenomenon has never changed since the emergence of life around 4 billion years ago?
The unfailing alternation between day and night, according to a never-changing 24-hour cycle. All living organisms that are exposed to light have had to adapt to this cycle and learn to live according to this rhythm.
Their internal clock follows what is known as a “circadian” rhythm, because it lasts one day.
All biological processes have evolved in line with this 24-hour cycle. What factors can affect this rhythm, which, today, is found in virtually all our cells? This is the enigma that Paolo Sassone-Corsi set out to solve.
When every cell beats to the passing of time
According to the classical biological model, complex organisms have a single internal clock located in a brain region called the hypothalamus, which beats to the rhythm of the Earth’s daily rotation around the Sun.
However, Paolo Sassone-Corsi’s work with zebrafish demonstrated the existence of peripheral clocks located in several of their body’s cells.
He then observed that single cells, isolated in vitro, are sensitive to light and oscillate according to a circadian rhythm, without receiving instructions from the brain. Simply exposing these cell cultures to light artificially alters their biological rhythm, to the point of reversing the day-night cycle.
Cyclic gene expression
Through the Liliane Bettencourt Prize for Life Sciences, the Fondation Bettencourt Schueller wanted to encourage Paolo Sassone-Corsi’s innovative research into the molecular mechanisms controlling circadian rhythms.
Among the processes involved in modulating cells’ physiological response to external stimuli, the research performed by Paolo Sassone-Corsi and his team is particularly focused on the role of hormone signaling and gene expression.
They studied the CREM gene, that has a role in cell proliferation and differentiation, and observed that its expression is regulated by a circadian rhythm. This discovery suggests that biological rhythms affect those important cellular processes.
This research has therefore been crucial in understanding how disrupted circadian rhythms affect health, as well as their incidence in diseases such as cancer.
Paolo Sassone-Corsi in a few words
While completing his PhD at the Institute of Genetics of the University of Naples, Paolo Sassone-Corsi developed an interest in a fundamental question: how is gene expression regulated?
Between 1979 and 1993, during his post-doctoral fellowship at the Molecular Genetics Laboratory in Strasbourg, he helped to elucidate transcriptional gene regulation.
In 1993, he chanced upon the discovery of a gene in the pineal gland whose expression levels oscillate to a rhythm. Initially, he thought there was some mistake - a post-doctoral researcher was observing high levels of expression, while a lab technician had not observed anything. It transpired that the post-doctoral researcher was running his experimental protocols at night, while the technician was doing so in the morning.
As a result, circadian rhythms, and their influence on gene expression and metabolism, became the primary focus of his pioneering work, which was honored with many awards, including the Liliane Bettencourt Prize for Life Sciences.
-
1979 PhD in Genetics, University of Naples (Italy)
-
1979 Post-Doctoral Fellowship as part of Dr. Pierre Chambon’s team, Laboratory of Molecular Genetics of Eukaryotes, CNRS, Strasbourg
-
1984 CNRS Researcher, 1st Class, Laboratory of Molecular Genetics of Eukaryotes, CNRS, Strasbourg
-
1990 CNRS Research Director, 2nd Class, Institute of Genetics and Molecular and Cellular Biology, Strasbourg
-
1996 CNRS Research Director, 1st Class, Institute of Genetics and Molecular and Cellular Biology, Strasbourg
Liliane Bettencourt Prize for Life Sciences
The Liliane Bettencourt Prize for Life Sciences rewards each year a researcher under the age of 45 for the excellence of their work and their remarkable contribution to their field of scientific research. This prize is awarded, depending on the year, to a researcher based in France or working in another European country. Twenty-seven winners have been awarded since 1997. From 2023, prize rewards the laureate up to 100,000 euros.
All the award-winners