- New micro heart
muscles from stem cells generated
- The key finding
could revolutionize the heart disease treatment
- Drugs can be
tested on the heart muscle cells to ensure that the drugs are safe to use.
Scientists have found
that heart muscles that are made from stem cells have the same expression
pattern of genes as that of the donor's native heart tissue. This has
completely revolutionized the treatment of cardiac diseases.
are cells with the remarkable ability to divide into many cell
types. They are present during the early stages of growth as they develop into
the different organ systems. Later in life, stem cells are present in the
different organs to replenish the organ with new cells or to repair.
‘Cardiac care could soon be tailor made for individual responses to drugs.’
Stem cells can divide to
form more of the same stem cells or they can divide and form specialized cells
like the neuron cells, red blood cells or even the heart cells.
Micro Heart Muscles
from Stem Cells
A new method of deriving
cells from stem cells
was identified by researchers from Gladstone
Institute this year in the journal title Scientific
. Earlier scientists derived heart muscle cells from induced
pluripotent stem cells but it was very difficult to get access to these stem
cells and very difficult to make them grow into the desired specialized cell.
Moreover, even when they grew, they resembled heart cells that were there in an
embryo rather than the heart muscles that exist in an adult. This made it
difficult to carry out drug testing using these cells as it still remained a
mystery how the actual beating heart would react to the medication.
The researchers first
isolated heart muscle cells and connective tissue cells from the induced pluripotent stem
. They were then arranged in the shape of a dog bone and allowed
to grow. The heart muscle cells then grew like neuronal cells and began to
'behave' like adult muscle cells. The scientists tested to see if the heart muscle
cells were indeed adult like by adding chemicals that were toxic to fetal heart
cells but not to adult cells. The micro heart muscles
were found to be functioning,
indicating that they were like adult cells.
Dr. Bruce Conklin, MD,
who is the senior author of the study said "The beauty of this technique is
that it is very easy and robust, but it still allows you to create
three-dimensional miniature tissues that function like normal tissues. Our
research shows that you can create these complex tissues with a simple template
that exploits the inherent properties of these cells to self-organize. We think
that the micro heart muscle will provide a superior resource for conducting
research and developing therapies for heart disease."
Testing Drugs on Heart
Muscle Cells from Stem Cells
Scientists from Stanford
University have said that the muscle cells from stem cells express the same
genes as adult heart cells, which make them ideal for testing drugs that could
lead to heart damage.
There are two
essential benefits in using these muscle cells that have been derived from stem
- Some drugs used
for medical conditions other than for the heart could affect the heart,
which makes it highly risky to use them. These drugs can be tested on the
heart muscle cells to ensure that the drugs are safe to use.
- More precise
cardiac medications can be designed as the effect of the drugs on the
heart muscles can be determined.
Dr. Joseph Wu who is the
Director of the Stanford's Cardiovascular Institute while also a professor of
radiology and of cardiovascular medicine says "Thirty percent of drugs in
clinical trials are eventually withdrawn due to safety concerns, which often
involve adverse cardiac effects. This study shows that these cells serve as a
functional readout to predict how a patient's heart might respond to particular
drug treatments and identify those who should avoid certain treatments."Testing the Expression
Dr. Wu and Dr. Elena
Matsa along with their colleagues created cardiac muscle cells from induced
pluripotent stem cells. They isolated the heart muscle cells from 7 different
people who were not known to have any genetic risk associated with cardiac
ailments. The level of expression of RNA by the heart muscle cells was
determined and the quantity of protein that they expressed. The values were
compared within the individual as well as among the seven individuals.
researchers studied the effect of two drugs on the cardiomyocytes.
Both these drugs illicit
cardiac effects on certain people but it is difficult to ascertain who might be
affected by these drugs.
When asked about the
result of the study Dr. Matsa said "We found that the gene expression patterns
of the iPS cell-derived cardiomyocytes from each individual patient correlated
very well. But there was marked variability among the seven people,
particularly in genes involved in metabolism and stress responses. In fact, one
of our subjects exhibited a very abnormal expression of genes in a key
metabolic pathway. This person's cells
produced abnormal amounts of reactive oxygen species, were unable to regenerate
their mitochondria and contracted much more weakly when exposed to
rosiglitazone than cells derived from the other subjects." Identifying the Error
identified the genetic mutation that leads to the abnormal pathway by comparing
the pathway followed by the other six unaffected individuals' cells. They used
a gene editing technique to correct the error which increased the expression of
a gene with a return of normal function.
The scientists were not
sure if the heart muscle cells that were derived from the induced pluripotent
stem cells could be compared entirely with the native cardiomyocytes. They
derived three more cardiac muscle cells from the induced pluripotent stem cells
of three cardiac patients and studied the expression levels. They found
similarity, especially in metabolic processes that were important to good
The study by Standford
researchers will aid in more precise medications being prescribed to patients,
without worrying about adverse effects to the heart. It could soon herald in a
tailor made treatment platform where the drugs for treatment could be chosen
based on the individual response of the patient, promising better treatment, faster
recovery and without adverse effects.
- Stem Cell Basics - (http://stemcells.nih.gov/info/basics/pages/basics1.aspx)
- Types of Stem Cells - (http://www.closerlookatstemcells.org/learn-about-stem-cells/types-of-stem-cells)
- Micro Heart Muscle Created from Stem Cells - (https://gladstone.org/about-us/press-releases/micro-heart-muscle-created-stem-cells)