June 21, 2012
Stem Cells To Aid In Heart-Related Research
Connie K. Ho for redOrbit.com
Pumping vigorously night and day, the heart is clearly one of the most important organs in the human body. It is also one of the most delicate parts of the body. As such, news regarding heart-related diseases is beneficial to both doctors and patients. University of Michigan (UM) researchers recently reported the discovery of a new method that could produce cardiac muscle patches from stem cells.The innovative process was created at UM´s Center for Arrhythmia Research and effectively uses stem cells that can copy the heart´s squeezing action. The cells showed activity that was like that of people´s resting heart rate. The rhythmic electrical impulse transmission of the engineered cells worked at a rate of 60 beats per minute and this rate was 10 times quicker than rates reported in other stem cell studies.
"To date, the majority of studies using induced pluripotent stem cell-derived cardiac muscle cells have focused on single cell functional analysis," remarked senior author Dr. Todd J. Herron, an assistant research professor in the Departments of Internal Medicine and Molecular & Integrative Physiology at the U-M, in a prepared statement.
The researchers believe that the stem biology findings will be beneficial to those who suffer from common but life-threatening heart diseases. They hope that the use of stem cells will assist patients diagnosed with arrhythmia, which is found in approximately 2.5 million people. With arrhythmia, patients suffer an irregularity in the heart´s electrical impulses and this can hinder the heart´s ability to circulate blood.
"For potential stem cell-based cardiac regeneration therapies for heart disease, however, it is critical to develop multi-cellular tissue like constructs that beat as a single unit," commented Herron in the statement.
Regarding the specifics of the project, the goal of the scientists was to use stem cells to develop skin biopsies. These biopsies could be used to produce large quantities of cardiac muscle cells, which could then help transmit uniform electrical impulses and work as a cohesive unit. In collaborating with researchers from the University of Oxford, Imperial College, and the University of Wisconsin, the team was able to design a fluorescent imaging platform. The platform used light emitting diode (LED) illumination to quantify the cells´ electrical activity.
"Action potential and calcium wave impulse propagation trigger each normal heart beat, so it is imperative to record each parameter in bioengineered human cardiac patches," remarked Herron in the statement.
Overall, authors of the study believe that the velocity of the engineered cardiac cells is still slower than the velocity of cells found in the beating adult heart. However, the velocity of the engineered cardiac cells is quicker than those previously reported; it is also similar to the rate found in commonly used rodent cells. For future scientific research purposes, the investigators theorize that human cardiac patches could be utilized instead of rodent systems. The new method could be used in many cardiac research laboratories and allow cardiac stem cell patches to be utilized in disease research, new drug treatment testing, and therapies focused on repairing damaged heart muscles.