Gravity’s Impact on Cell Movement in a Face-Down Position

Researchers at the National Institute for Materials Science (NIMS) and their colleagues in Japan have developed a custom-coated, light-responsive surface that helps test how the direction of gravity affects cell movements. The results published in the journal Advanced Materials Science and Technologycould lead to a better understanding of what happens to cells in prolonged bedridden subjects and the effect of gravity orientation on cancer cell migration.

Special surfaces are made by coating glass slides with a mixture of light-responsive molecules. Highlighting a central circular area of ​​the slide breaks up the particles, removing a coating-free area to which cells can adhere. Once settled in this region, the scientists use light to scan the area around the central circle. This encourages the cells to move in an outward direction to fill the box.

The team studied what happens to cell motion when the slide is held upright, with the cells on top and the direction of gravity affecting the cells from top to bottom. Then they did a similar test with the slide upside down while supporting it on both sides so that the cells flipped over and the direction of gravity was from the bottom of the cells to the tops of the cells.

“We found that the direction of gravity impedes the collective migration of cells in the reversed mode by reducing the number of outward-moving pioneer cells at the edges of the cluster and redistributing the shape-forming filaments, made up of actin and myosin, so that they keep the cells bundled together,” explains biomaterials researcher Shaima Abdul Latif, a postdoctoral researcher at NIMS.

Light-responsive coated surfaces offer an advantage over currently available methods that study the effects of gravity orientation, because they require physical contact with the surface to which the cells are attached. The new approach enables remote induction of cell migration.

“We plan to apply our approach to analyze the responses of cancer cells to the direction of gravity,” says Jun Nakanishi, a nanoscientist at NIMS, who led the study. “We expect to find differences between healthy and diseased cells, which can provide important information about cancer development in bedridden patients.”