Cedars-Sinai Heart Institute researchers have found that six proteins – five more than previously thought – are responsible for cell-to-cell communication that regulates the heart and plays a role in limiting the size of heart attacks and strokes.
The smallest of these proteins directs the largest in performing its role of coordinating billions of heart cells during each heartbeat. Together, the proteins synchronize the beating heart, the researchers determined.
"We now know these proteins exist," said Robin Shaw, MD, PhD, the senior author of the study published in the journal Cell Reports. "The findings advance our understanding of cell-to-cell communication at the root of healthy heart function. When there is less cell communication, which occurs in failing hearts, chances are greater of disturbances in heart rhythm that can result in disability or death."
Until now, scientists had recognized just one protein involved in cell-to-cell communication that occurs through conduits known as "gap junctions." The Cedars-Sinai researchers identified five additional proteins that regulate the rapid flow of electrical communication signals, coordinating heart cells to produce a stable heartbeat.
"The finding of alternative translation start sites within this important group of proteins adds startling diversity to a key biological process, namely that whereby heart cells communicate with each other electrically," said Eduardo Marbán, MD, PhD, director of the Cedars-Sinai Heart Institute. "The implications are major for arrhythmias and heart failure."
Through a phenomenon called "alternative translation," the protein-making machinery in each cell can produce shorter proteins from the same gene that encodes the largest of the proteins. Biologists had known of the existence of alternative translation but had not completely understood its physiological relevance. The Cedars-Sinai research team led by Shaw has expanded the understanding of this process and continues to study the precise role of the proteins produced by it.
The researchers also have determined that a class of drugs known as "mTOR inhibitors" – those already used for immunosuppression in organ transplants – can affect alternative translation, changing the balance of proteins in hearts cells, increasing the amount of electrical coordination in the heart. The findings suggest that mTOR inhibitors can be used to prevent erratic and sometimes fatal heart rhythms.
A properly beating heart is necessary to pump blood to the brain, lungs and other organs. When arrhythmias occur in the heart's main pumping chamber, the heart can stop, resulting in sudden cardiac arrest, the most common cause of death among heart patients. Preventing arrhythmias is a top clinical priority. The possibility of using mTOR inhibitors suggests that drugs used to treat transplanted hearts could also be used to treat failing hearts.
Cell-to-cell communication occurs in all other organs. The same proteins that help heart cells communicate also play a role in brain function, bone development and insulin production in the pancreas. These proteins also affect the contraction of muscle cells within the uterus during childbirth and may potentially suppress cancer cells. The finding that mTOR inhibitors improve cell-to-cell communication indicates that this class of drugs could be useful to treat multiple disorders.
Sally Stewart | EurekAlert!
A promising target for kidney fibrosis
21.04.2017 | Brigham and Women's Hospital
Stem cell transplants: activating signal paths may protect from graft-versus-host disease
20.04.2017 | Technische Universität München
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
Two researchers at Heidelberg University have developed a model system that enables a better understanding of the processes in a quantum-physical experiment...
Glaciers might seem rather inhospitable environments. However, they are home to a diverse and vibrant microbial community. It’s becoming increasingly clear that they play a bigger role in the carbon cycle than previously thought.
A new study, now published in the journal Nature Geoscience, shows how microbial communities in melting glaciers contribute to the Earth’s carbon cycle, a...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
21.04.2017 | Physics and Astronomy
21.04.2017 | Health and Medicine
21.04.2017 | Physics and Astronomy