Just like our sense of touch allows us to feel a gentle hug, the tiny cells in our bodies also respond to physical forces. This response is crucial for our bodies to function properly, and understanding it can unlock secrets of how diseases develop, guiding us towards new treatments.

In the vast universe of our cells, there are specialised structures called mitochondria, often referred to as the power plants. They generate the energy our cells need to work and grow. These tiny powerhouses are enclosed by two layers of membranes, not unlike the insulation around a battery.

The Duan Lab from Biomedical Engineering has pioneered a groundbreaking way to study these cellular power plants, using a technique inspired by the principles of optogenetics, which is a method that uses light to control cells. Imagine using a flashlight to command cells to act; that's how this new tool works. By shining light on these mitochondria, the researchers can effectively apply physical force to mitochondria without the need to actually touch and possibly damage the delicate structures within our cells.

With this light-based tool, the researchers made a fascinating discovery. It turns out, mitochondria can feel the “force” of the light, causing them to divide, much as a single drop of water can split into two smaller droplets. They observed that when mitochondria sense the force, they can pinch off a piece of themselves in a process that's reminiscent of how a lizard might shed its tail when threatened. This act of self-preservation allows mitochondria to remove damaged parts and maintain their health. Moreover, the researchers found that this force could cause the outer layer of the mitochondria to peel off, forming tiny bubbles that carry away unwanted material, which is a process that has rarely been identified before. This is akin to shedding an old coat to preserve the new one underneath.

These insights open up new pathways for understanding how our cells’ energy producers are influenced by the physical world around them. By delving into the ways mitochondria react to forces, we can start to decode more of the biophysical mysteries related to these enigmatic components of our cells.