Scientists use centrifuge to discover a hormone
Discovering compounds with therapeutic potential that were previously hidden by highly numerous proteins is the goal of a new technique for isolating extracellular fluid.
Muscles are not isolated entities; in order for the body to operate as a whole, they must interact with one another and the brain. However, it has been challenging to pinpoint precisely which molecules are engaged in this communication since they are frequently overshadowed by other, more prevalent biomolecules. According to a study published Friday (January 20) in Cell Metabolism, a team of researchers has now discovered a quicker and simpler method to identify these molecules. Researchers may be able to identify proteins that can be utilized in treatments and better understand how muscles communicate using the new approach.
The work, in the opinion of molecular physiologist Christopher Newgard of Duke University Medical Center, is “remarkably fundamental.” “It almost seems too simple compared to other approaches that tried to do this in the past.”
Bruce Spiegelman, a cell biologist at Harvard’s Dana-Farber Cancer Institute and the paper’s lead author, has been studying the hormones that muscles and fat release during exercise and how those hormones affect the body as a whole for more than ten years. The hormones he was looking for were, however, overshadowed by other, more dominant proteins when he employed mass spectrometry to analyze entire muscle and fat tissues, such as albumin (which is a plentiful component of blood). Spiegelman reasoned that by separating this extracellular fluid, he would be able to investigate the hormones more precisely and possibly discover new ones. Spiegelman was aware that after being secreted, these hormones accumulate in the extracellular fluid surrounding tissues.
Spiegelman decided to attempt a similar technique to isolate molecules from extracellular fluid after observing Harvard colleagues utilize centrifuges at extremely low speeds to separate out tiny metabolites. He set up an experiment by adding some muscle tissue to a centrifuge. The centrifuge needed to spin quickly enough to separate the fluid from the muscle tissue without becoming too rapid. This proved to be more challenging than anticipated. Spiegelman and the rest of the crew eventually settled on a centrifugal force that was around 600 times that of gravity. They were able to separate a pinkish-yellow liquid from the muscle at this pace. The researchers passed the fluid through gel electrophoresis and then analyzed it using mass spectrometry after centrifuging it once more to get rid of as much of the leftover albumin and immunoglobulins as they could.
It didn’t appear like muscle or blood, according to the computer analysis of the mass spec, says Spiegelman. We were hoping for something different, and that’s what we got.
The researchers then began the challenge of looking for new biomolecules with presumptive extracellular fluid in hand. After some research, they identified a hormone produced by muscles and fat that they dubbed prosaposin. They discovered that the newly discovered protein aids in mice’s thermogenesis, suggesting that it may be effective in therapies for obesity since it might help burn fat. Spiegelman finds it “very intriguing” that “we uncovered a bona fide neurotrophic factor coming out of the muscle.” “And there was no other way we could have done it.”
Spiegelman plans to use this approach to carry out additional studies into the protein composition of muscle and fat tissues in order to advance knowledge of the challenges with intercellular communication that are associated with neurodegenerative illnesses and malignancies. Newgard does issue a warning that there is still some work to be done. A few proteins typically seen in plasma were discovered in the centrifuged extracellular fluid, as was indicated in the research, which suggests that plasma may be leaking into the purportedly separated fluid. However, he is optimistic that the work will be useful to other researchers in the future.
There are still some unanswered questions, he argues. However, I would describe it as a pretty daring first effort.
