Faculty researchers and scientists from the Georgia Institute of Technology have generated new insights into how cells stick to each other and to tissue structures known as extracellular matrices. These are essential functions in the formation of organs and organisms. Abnormalities in these areas are thought to play important roles in a range of disorders involving cell adhesion and movement, including cardiovascular disease and cancer.
The findings outline a surprising aspect of cell adhesion, involving molecules known as integrins. The research uncovered a phenomenon termed ‘cyclic mechanical reinforcement,’ in which the length of time bonds between cells and their surroundings exist is extended through repeated pulling and release between the integrins of the extracellular matrix. Professor Martin Humphries, Dean of the Faculty, says the study suggests new capabilities for cells:
“This paper identifies a new kind of bond that is strengthened by cyclical applications of force, and which appears to be mediated by shape changes in integrin receptors. The findings shed light on a possible mechanism used by cells to sense extracellular topography and to aggregate information through ‘remembering’ multiple interaction events.”
Cheng Zhu, a professor at Georgia Tech, had this to say:
“Many cell functions depend on cell interaction with the ligands of the extracellular matrix. The cells respond to their environment, including many mechanical aspects. This study extended our understanding of how connections are made and how mechanical forces regulate interactions.”
Using delicate force measuring equipment, Professor Zhu and his collaborators studied adhesion between integrin and a protein component of the extracellular matrix known as fibronectin. Cyclic forces applied to the bond switched it from a short-lived state with lifetimes of roughly one second, to a long-lived state that can exist for more than one hundred seconds.
The researchers now hope to determine whether or not the cyclic mechanical reinforcement they observed is a universal property of cellular adhesion molecules. They hope to discover how cells use this cyclic mechanical reinforcement, so they can form a better understanding of the processes that allow cells to move together with the abnormal cellular adhesion mechanisms that occur in diseases.