It's not the amount of fat, but the ability to store fat in the right locations, that equates to good metabolic health in humans. In part, for this to occur, new fat cells must be made "on demand" when the body has an energy surplus.
John Bracht, American University biology assistant professor, and his students discovered a new type of cell state that could help ensure one always has the ability to generate healthy fat cells. The finding falls in line with increasing scientific discoveries elucidating how complex our cells are and how much we have yet to learn about their makeup.
The discovery involves stem cells. Stem cells are usually thought of as replicating cells. Other cells perform specific functions. To turn into a specialized cell, a stem cell must be given instructions. As the team grew stem cells in the petri dish, they noticed some stem cells not following orders. They were curious. If the stem cells wouldn't turn into fat cells, then what did they become? Eventually, the team found that the rogue cells could differentiate and become fat cells.
As the team examined the rogue cells, they found a mixture of characteristics. The rogue cells were neither replicating nor differentiating. They were dormant. Interestingly, their gene expression was similar to fat cells.
With all of these clues pointing toward the rogue cells being stem-like, the team continued their work. Finally, the team found the dormant cells could awaken, become active stem cells, and turn into useful fat, bone or cartilage--fulfilling a definition of true stem cells, in spite of their unusual behavior and fat-like gene expression.
"The research results tell us that stem cells are not all that we think they are. A stem cell might look very different, molecularly, than we previously thought," Bracht said. "Perhaps stem cells are residing in unexpected places."
When it comes to fat cells, size (and location) matters
Critical to health is the body's generation of the right kind of fat cells, which is the kind that live under the skin. A scientific theory about obesity, called the adipose expandability hypothesis, describes the limits at which the body creates healthy fat cells. When healthy fat cells cannot be made under our skin, existing fat cells grow bigger, and fat gets stored in other parts of the body. That's when adverse health outcomes arise such as heart disease, cancer and other illnesses.
Bracht likens what he observes in the petri dish to what could be happening in the body. "Our idea is that the rogue cells represent what the body would normally keep as a stem cell reservoir in the fat," Bracht said. "This reservoir is critical. If you run out of these rogue cells, or you're unable to make new fat cells, fat could get deposited in areas of the body where it's unhealthy."
In other words, if all stem cells followed directions and turned into fat, the body would reach a limit of how much healthy fat to store. These rogue cells breaking off from this process could be a way to maintain healthy fat.
The next step of the research will be to use mouse models to study the dormant cells and investigate a gene the team identified and believes plays a role in determining the rogue cells' fate.
"We want to figure out how do these cells decide whether they're going to accumulate fat or not. There's something behind that - some gene program and epigenetics mechanism," Bracht said. "We're busily following up in the lab on that right now."
The team collaborated with researchers at Georgetown University's Flow Cytometry facility. The research paper, "Discovery of a stem-like multipotent cell fate," has been published in the American Journal of Stem Cells. In addition to Bracht, authors are Paffhausen, E.S., Alowais, Y., Chao, C.W., Callihan, E.C., and Creswell, K.
Rebecca Basu | EurekAlert!
Lethal combination: Drug cocktail turns off the juice to cancer cells
12.12.2018 | Universität Basel
Smelling the forest – not the trees
12.12.2018 | Universität Konstanz
A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.
The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...
A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.
Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...
Over the last decade, there has been much excitement about the discovery, recognised by the Nobel Prize in Physics only two years ago, that there are two types...
What if a sensor sensing a thing could be part of the thing itself? Rice University engineers believe they have a two-dimensional solution to do just that.
Rice engineers led by materials scientists Pulickel Ajayan and Jun Lou have developed a method to make atom-flat sensors that seamlessly integrate with devices...
Scientists at the University of Stuttgart and the Karlsruhe Institute of Technology (KIT) succeed in important further development on the way to quantum Computers.
Quantum computers one day should be able to solve certain computing problems much faster than a classical computer. One of the most promising approaches is...
12.12.2018 | Event News
10.12.2018 | Event News
06.12.2018 | Event News
12.12.2018 | Health and Medicine
12.12.2018 | Physics and Astronomy
12.12.2018 | Health and Medicine