Researchers at UC San Francisco (UCSF) have developed molecules that act like a 'cell glue', precisely controlling how cells stick together. This discovery represents a major breakthrough in the construction of tissues and organs, a goal long pursued by regenerative medicine.
The "adhesive" molecules are already found naturally throughout the human body. They hold together its tens of trillions of cells in a highly organized way. They form structures, create neuronal circuits and guide immune cells towards their targets. Furthermore, adhesion facilitates communication between cells to maintain balance of the body as a self-regulating system. With adulthood, many of the molecular instructions that guide these generative processes disappear and some tissues, such as nerves, are no longer able to recover from injury or disease. Regenerative medicine seeks to use these adhesive molecules to help tissue regenerate and heal.
New perspectives for regenerative medicine
In the December 12, 2022 issue of Nature, a new study (I link it here) showed how researchers were able to engineer cells to control interactions with other cells. The study's senior author, Dr Wendell Lim, underlined the importance of this discovery for the field of regenerative medicine, with the possibility of building organs and tissues much easier and faster.
"The structure of a tissue, such as skin, depends largely on how the different cells are arranged within it," he says. Adam Stevens, Ph.D. of the Cell Design Institute and other lead author of the paper.
We are trying to control this cellular organization, which is essential for creating fabrics with the desired properties.
How the mechanism developed by UCSF scientists works
The distinctive quality of a tissue is often determined by the close connection of its cells. In a solid organ such as the lung or liver, the cells are often tightly bound together. However, in the immune system, the weaker bonds allow cells to flow through blood vessels or crawl between narrower skin or organ cells to reach a pathogen or wound. Researchers have created molecules that split into two parts to control cellular connection. One part acts outside the cell, causing it to interact with other cells. The other part, inside the cell, regulates the strength of the bond. These parts can be easily combined and modified to create different cells that bind differently.
"It's really exciting that we now have a better understanding of how evolution managed to build bodies," Stevens added. 'Our work has unveiled a flexible molecular adhesion code that determines how cells interact with each other. Now that we are starting to understand this, regenerative medicine could harness this code to influence how cells assemble into tissues and organs. These tools could be truly game-changing."