Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists Discover New Pathway Critical to Heart Arrhythmia

31.10.2011
University of Maryland School of Medicine researchers have uncovered a previously unknown molecular pathway that is critical to understanding cardiac arrhythmia and other heart muscle problems. Understanding the basic science of heart and muscle function could open the door to new treatments.

The study, published recently in the journal Cell, examined the electrical impulses that coordinate contraction in heart and skeletal muscles, controlling heart rate, for example. Unraveling how the body regulates these impulses is key to understanding serious health conditions such as paralysis, muscle relaxation and heart arrhythmia.

Researchers in the Cell study examined ion channels — membrane proteins that allow the electrical charges to flow into and out of the cell. The number and location of channels on the cell’s surface are critical to the heart’s rhythm. The University of Maryland School of Medicine scientists found a new, previously unknown intracellular trafficking pathway that controls the number and location of the ion channels on the cell surface, affecting the passage of electrical charges and controlling the beat of the heart and other muscle activity.

Ion channels are proteins that form pores at the cell’s surface. The pores open with careful regulation, allowing the passage of ions like potassium, sodium or chloride. These ions carry distinct electrical charges, and their regulated passage into and out of the cell stimulate and coordinate contractions such as the heart’s rhythm.

“This study illuminates a new pathway for therapeutic intervention,” says Paul Welling, M.D., professor of physiology at the University of Maryland School of Medicine. “Drugs that interfere with or augment this signal may be used to control the number and location of ion channels in such a way to fight arrhythmia and other muscle disorders, potentially saving lives.”

“Dr. Welling’s research is an example of the world class basic science discoveries taking place at the School of Medicine, discoveries that we hope one day will lead to relief and new treatments for patients and their families,” says E. Albert Reece, M.D., Ph.D., M.B.A. vice president for medical affairs for the University of Maryland, and John Z. and Akiko K. Bowers Distinguished Professor and dean of the University of Maryland School of Medicine.

Until recently, scientists have focused on the regulatory mechanisms that control the way that these ion channels open and close and how that action affects muscle contraction and heart rate. Years of research have shown that it is not simply the action of these ion channels that affects heart arrhythmia Scientists have found that the location and number of channels on the cell’s surface are just as important to the heart’s rhythm. The study in Cell describes a new intracellular trafficking pathway that controls the number and location of these ion channels on the cell surface.

“Previously, we were unsure how the ion channels get out to the surface of the cell,” says Dr. Welling. “We found a new mechanism that operates like a molecular zip code, ensuring that the appropriate numbers of ion channels are sent to the correct cellular location, the cell surface. It also functions as a type of proofreading mechanism, making sure that only correctly made ion channels make it to the cell surface.”

Dr. Welling and his colleagues examined the molecular pathology of the genetic condition Andersen-Tawil Syndrome, characterized by uncoordinated muscle contractions, paralysis and disruptions in the normal heart rhythm. The syndrome is caused by mutations in the gene known as KCNJ2, which encodes a potassium channel in the heart and skeletal muscle known as Kir2.1.

The scientists examined how mutations in the potassium channel affects its passage through a key intracellular sorting station called the Golgi apparatus. The Golgi apparatus modifies, sorts and packages molecules for the cell’s use. Dr. Welling’s lab found that the Golgi apparatus selects the Kir2.1 channel to travel to the surface of the cell in an unusual, signal-dependent manner. The signal determines where the Golgi apparatus sends the potassium channel and how many it sends and verifies that the channels are of quality. In patients with Andersen-Tawil Syndrome, the signal is faulty and fails to properly regulate the ion channels and their path to the cell surface.

“Elucidating the mechanisms behind this rare disease provides insight into more prevalent forms of arrhythmia such as heart failure,” says Dr. Welling. “There is great interest in understanding the mechanisms by which cardiac ion channels are regulated. This new pathway may be an excellent target for therapeutic intervention for both Andersen-Tawil syndrome and the far more common condition, like arrhythmias associated with heart failure.”

The study has implications beyond the science of the heart, he added. The class of ion channels the researchers examined includes about 12 other ion channels that control various body processes from cognition to the salt balance in the kidneys. The next step for his lab, Dr. Welling says, is to study this pathway in relation to the kidneys. It is possible the same pathway affects the entire class of channels and helps regulate all the body processes associated with them.

Karen Robinson | Newswise Science News
Further information:
http://www.umaryland.edu

More articles from Life Sciences:

nachricht Cryo-electron microscopy achieves unprecedented resolution using new computational methods
24.03.2017 | DOE/Lawrence Berkeley National Laboratory

nachricht How cheetahs stay fit and healthy
24.03.2017 | Forschungsverbund Berlin e.V.

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>