Cells lacking nuclei struggle to move in 3-D environments

January 20, 2018 by Laura Oleniacz, UNC Lineberger Comprehensive Cancer Center
Two human endothelial cells are shown. The cell to the left had its nucleus removed. The cells have been stained with phalloidin to label in green the actin cytoskeleton, and with a different dye to label the nucleus red. Credit: UNC Lineberger Comprehensive Cancer Center

University of North Carolina Lineberger Comprehensive Cancer Center researchers have revealed new details of how the physical properties of the nucleus influence how cells can move around different environments - such as "soft" tissue like brain and fat, or "stiff" tissue like cartilage or bone.

The researchers removed the nucleus from cells or disconnected them from the cell's structural scaffolding known as the "cytoskeleton." They watched how the modified cells were able to move in different surfaces to better understand the role of this central cell structure in movement. Their findings from the study, published in the Journal of Cell Biology, contribute to the basic scientific understanding of the mechanical properties of the nucleus, and they also may shine more light on the role of the nucleus in diseases in which the nucleus can be disrupted or corrupted - like cancer.

"Whereas much is known about the function of the nucleus as a repository of DNA and site of gene regulation, our analysis concerns the role of the nucleus as a physical structure that is affecting cell behavior independent of gene regulation," said UNC Lineberger's Keith Burridge, PhD, Kenan Distinguished Professor in the UNC School of Medicine Department of Cell Biology and Physiology. "Our work shows that the physical presence of a cell nucleus regulates how a cell responds to the stiffness of its environment."

Two migrating cells are shown. The cell to the left has its nucleus intact, while the cell to the right is a cytoplast (the nucleus is removed). Both cells are migrating on fibronectin coated glass. Credit: David M. Graham

They found that cells without a nucleus, or in which the nucleus has been disconnected from the cells' structure, can migrate on rigid, two-dimensional structures such as a cell culture dish where scientists can grow and observe cells. However, they move more slowly on soft surfaces, and don't move at all on three-dimensional matrices. Their conclusion was that the nucleus affects how cells respond to their physical environment.

"We found that cells lacking a nucleus or with a disconnected nucleus exert less force and show decreased mechanical energy," Burridge said.

Their findings are important to the basic understanding of cell mechanics. But they could give insight into cancer and other diseases that affect the of the nucleus.

"Many cancer display abnormal nuclei that differ in their size, shape and ," said the study's first author David M. Graham, PhD, a postdoctoral research associate in the UNC School of Medicine Department of Cell Biology and Physiology. "Consequently, although our research is at a fundamental level of cell biology, we believe it should contribute to our overall understanding of these disease situations."

Explore further: Research reveals how cells rebuild after mitosis

More information: David M. Graham et al. Enucleated cells reveal differential roles of the nucleus in cell migration, polarity, and mechanotransduction, The Journal of Cell Biology (2018). DOI: 10.1083/jcb.201706097

Related Stories

Research reveals how cells rebuild after mitosis

December 4, 2017

When cells divide, they need to rebuild their nucleus and organise their genome. New collaborative research from the University of Bristol demonstrates how cells achieve this through the unexpected deployment of filamentous ...

Chromosome mechanics guide nuclear assembly

August 28, 2017

Every one of our cells stores its genome within the nucleus – the quintessential subcellular structure that distinguishes eukaryotic cells from bacteria. When animal cells divide, they disassemble their nucleus, releasing ...

Ryk needs a chaperone

November 27, 2017

Ryk has made the headlines by requiring a chaperone. But don't assume that Ryk is a badly behaved celebrity—it's actually a protein featured in a new study in the Proceedings of the National Academy of the Sciences (PNAS).

Spectrin proteins spring into action to restore nucleus

June 20, 2017

When you lift weights, carry heavy boxes, or engage in physical activity, the cells in your body stretch and deform to accommodate your movements. But how do your cells recover, or return to their original state, once you ...

Recommended for you

The source of stem cells points to two proteins

December 11, 2018

Mammalian embryos are unlike those of any other organism as they must grow within the mother's body. While other animal embryos grow outside the mother, their embryonic cells can get right to work accepting assignments, such ...

'Pest-controlling' bats could help save rainforests

December 11, 2018

A new study shows that several species of bats are giving Madagascar's rice farmers a vital pest control service by feasting on plagues of insects. And this, a zoologist at the University of Cambridge believes, can ease the ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.