Montreal researchers explain how your muscles are formed

All vertebrates need muscles to function. they are the most abundant tissue in the human body and are an integral part of the movement.

In a recent article published in Nature Communications, an international team of researchers has discovered two essential proteins for the development of skeletal muscle. This research, led by Jean-François Côté, professor at the Montreal Clinical Research Institute (IRCM) and at the Faculty of Medicine of the Université de Montréal, could provide a better understanding of rare and rare muscular diseases. to develop new treatments.

From nuclear fusion to cell fusion

Skeletal muscles are attached to our bones and allow our body to move. Whether in a developing embryo or in a professional athlete, the same sequence leads to its formation.

"In vertebrates, cells derived from stem cells, called myoblasts, align first and come together to the point of touching and compressing their cell membranes," explained the lead author of the cell. Study, Jean-Francois Côté, director of the Cytoskeleton organization of the IRCM. Cell Migration Research Unit.

In the end, myoblasts merge to create a large cell. This phenomenon, called "cell fusion", is very particular. "Cellular fusion only affects a few tissues, including the development of the placenta and the remodeling of our bones," said Mr. Côté.

The "dance" of muscle cells

To develop and repair muscles, myoblasts must perform their movements with the utmost care. No false movement is allowed, otherwise there will be defects. In their study, Côté and his team describe their discovery of two proteins – ClqL4 and Stabilin-2 – that regulate this singular choreography.

Indeed, ClqL4 and Stabilin-2 guarantee the success of this delicate sequence. They slow down and trigger cell fusion respectively at key moments. Their role is crucial: if the "metronome" of myoblasts is interrupted, the muscles will not be the right size and their function will be affected. This is what happens in muscle diseases characterized by a weakness that makes some movements difficult.

The discovery of proteins is the culmination of international collaboration between teams from Montreal, Japan, the United States and South Korea. "Our second author, Viviane Tran, one of my PhD students, spent time in Tokyo conducting important experiments in the laboratory of Michisuke Yuzaki, one of our collaborators," said Mr. Côté.

IRCM researchers have already embarked on the follow-up study. They want to determine if the results of their research could become a therapeutic target for rare muscle diseases such as myopathies and muscular dystrophies.

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About the study

"Spatiotemporal regulation of BAI3 GPCR activity by C1qL4 and Stabilin-2 controls myoblast fusion", by Jean-François Côté et al., Was published on October 26, 2018 in Nature Communications. Funding was provided by the Canadian Institutes of Health Research, the Transat Chair in Breast Cancer Research, the Quebec Health Research Fund, the Canada Research Chairs Program and the National Institutes of Health. United States.

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