The proteins that make some species of deep sea jellyfish glow are helping scientists study human heart cells. While it’s likely that these sea creatures evolved the ability to produce proteins for luminescence to scare away their enemies, scientists have found a way to adopt this technology for the advancement of medicine.
Using stem cells to create models for studying heart disease is no foreign concept to researchers specializing in cardiac dysfunction. Creating induced pluripotent stem cells from human skin cells capable of transforming into heart muscle cells (cardiomyocytes) allows scientists to study things like how heart cells might respond to different drugs
. Using stem cells instead of relying on native cardiomyocytes removes the need for obtaining heart samples, which can be difficult to do.
In a new study from the Technical University of Munich (TUM), published in the European Heart Journal,
researchers used jellyfish DNA to manufacture fluorescent proteins inside cardiomyocytes, enabling the scientists to learn more about the properties of the heart and heart muscle than ever before.
In the past, scientists have used microelectrodes to directly determine the strength of a cell’s electrical signals. However, this process can only be used on a small number of cells. Applying jellyfish DNA was found to be a much more efficient way of detecting electrical activity. Additionally, the researchers from TUM were also able to identify cell types with this technology faster than ever thought possible.
"We can already investigate hundreds of cells in one day instead of only a handful," says Zhfen Chen, first author of the study. "This process can basically be automated and scaled up, so that thousands of cells can be investigated at the same time."
Chen and the rest of the team built the so-called “biological sensors” by inserting fluorescence DNA from jellyfish into cardiomyocytes procured from induced pluripotent stem cells. Just like it does naturally in deep sea jellyfish, the genetic material led to the production of sensor proteins in the cardiomyocytes. After stimulation with light at a specific wavelength, researchers successfully saw the cardiomyocytes produce light at a different wavelength, simulating the process of jellyfish fluorescence in the deepest and darkest parts of the ocean.
They found that the color of light produced by the cardiomyocytes is determined by the voltage difference between inside and outside of the cell, so the researchers could use this information to measure and record action potential of individual cells.
Although all cardiomyocytes share a primary function of working to keep the heart beating, specific cells from different parts of the heart have varying action potentials, electrical voltage, and other qualities. Since the new technology facilitates the measurement individual cell action potential, specific cell types can be identified based on this information.
Certain cardiac rhythm disorders are directly related to malfunctions in specific places of the heart, making the use of this technology extremely relevant for studying these conditions. Plus, the jellyfish DNA inserted into cardiomyocytes can be specifically designed to couple with specific recognition DNA sequences, called promoters. This intricate design ensures the sensor proteins will only be produced in designated cell types, allowing scientists to capture information on electrical signals from specific groups of cardiomyocytes.
In the future, the team from TUM plans on improving the sensitivity of their technology in addition to using their research to test drugs, looking for negative side effects on heart muscle.
Sources: Technical University of Munich
, Scripps Institution of Oceanography