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If you’ve never seen a cell divide, under a fluorescent microscope, google it or drop by for a visit. It’s beautiful. It’s like two exploding stars slowly moving apart. The thin lines streaming from one end of the cell into the middle are microtubules, hollow fibers that form a network that facilitates the mechanics of cellular processes like cell division and cell movement.

Both cell division and migration are critical for angiogenesis, the formation of new blood vessels from existing ones, which is important for embryonic development, wound healing, and often plays a role in disease progression, such as cancer metastasis.

Centrosomes anchor and stabilize microtubules

I’m studying the impact of microtubule organization and geometry during angiogenesis, something that hasn’t been investigated before.

During angiogenesis, cells divide and migrate in a collective manner. When a cell wants to move in a certain direction in order to build a new vessel, it makes a sprout, which is filled with microtubules. Under the microscope, we can see that cells first make unstable protrusions in all directions. At some point, a cell chooses one direction to elongate and enriches microtubules in that direction. This results in asymmetry or polarity within the cell and facilitates guided movement.

In the late 1880s, observations with low power microscopes identified a region inside the cell called a centrosome, that anchors, organizes and stabilizes microtubules; since then, centrosomes have been directly linked to cell polarity.

We’ve discovered a new architectural design

With the development of super-resolution imaging technologies and the ability to image in 3D, we are now able to look in depth at events that occur during cell division and migration. In fact, we can now clearly see where individual microtubules originate from, and in contrast to prior observations, our research shows that centrosomes are not critical for angiogenesis. If we remove the centrosome with a drug, we find that cells can still polarize.

This provides us with exciting options for targeting angiogenesis within a disease context. How do cells decide where to polarize and where to stabilize? We think that microtubules are not the primary effector. They are important for stabilizing polarity in a cell, but there are probably upstream signaling; we need to look at other factors.

I joined Anna Akhmanova’s lab and its impressive microscopy facility three years ago, and the freedom I have to explore this new untouched topic is thrilling. This, together with Anna’s mentorship energizes me during my weekly commute from southern Belgium.

Maud Martin, PhD
Post-doctoral researcher
Group: Anna Akhmanova, PhD
Cell Biology