Regeneration of cardiomyocytes using bone marrow derived stem cell transplantation and other factors involved in heart repair.
1. Review Article
Regeneration of Cardiomyocytes by Using Bone Marrow Derived Stem Cell
Transplantation and Other Factors Involved in Heart Repair
Pablo González
Abstract:
The heart is a very important organ in our body because it is in charge of pumping the
oxygenated blood through the veins and capillaries. One way it can be affected is by suffering a
heart attack. A heart attack can affect the heart by lowering its ability to pump and not carrying
the needed amount of oxygen through the body. If the heart continues at that rate its cells will be
damaged from lack of oxygen and the individual will suffer from heart failure. There are still no
cures for heart failure, although there are treatments. One very important treatment is Bone
Marrow Cell transplantation which consists of transplanting derived stem cells from the bone
marrow and injecting them into the cardiomyocytes. Stem cells will differentiate into heart cells,
taking the place of the destroyed ones. Transplantation therapy still needs more research, but it
has shown significant results in the regeneration of cardiomyocytes. Other types of heart therapy
are Vascular Endothelial Growth Factor intravenous injection and Drug Combination therapy.
The first one consists of injecting the myocardium with vascular endothelial growth factor which
will have an angiogenic and therapeutic effect. The second treatment requires the administration
of drugs such as statins, after the infarction to improve the viability of bone marrow derived stem
cell transplantation.
Introduction: The heart, a muscle approximately the size
of a fist, is a vital organ. It contains four
cavities: two atria, and two ventricles, and
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2. pumps oxygenated blood through all the The results of this treatment have shown to
veins and capillaries in our body. The cells improve the cardiac function. However,
that make up the heart are called myocytes many have postulated that the mechanism of
or cardiomyocytes. When these cells suffer action of BMC therapy is via the release of
the consequences of a heart attack, it is very paracrine factors such as vascular
difficult for the heart to replenish or endothelial growth factor. Aside from this,
regenerate them causing heart failure and research has shown that implanted cells have
possible death. not been shown to survive in myocardium
for long periods (Yeghiazarians 2009).
Currently there is not a cure for heart
failure, but there are still treatments such as Discussed in this review article are the
medicines and a healthier lifestyle (National current experiments and views on
Heart Lung and Blood Institute 2010). A transplantation of bone marrow derived stem
healthier life style includes doing exercise, cells on infracted hearts and the different
eating healthy, managing stress, ect. One factors that affect them.
new and very important treatment is the
What is heart failure?
transplantation of bone marrow derived cells
(BMCs). This treatment consists of When someone suffers a myocardial
transplanting stem cells derived from the infarction (heart attack), the heart may
bone marrow to the heart. When become scarred and lose its ability to pump
transplanted, the cells begin to differentiate enough blood through the body. A heart
into heart cells (cardiomyocytes), filling the attack occurs when plaque builds up inside
place of the previously destroyed ones. the coronary arteries, cutting off the oxygen
rich blood to the heart. This is called
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3. coronary heart disease and it is the number Bone Marrow Derived Cells:
one cause of heart attacks. If blood flow is
To solve the problems previously stated
not restored quickly, the section of heart
scientists are experimenting with the
muscle without oxygen begins to die. The
injection or extract of the cells derived from
part of the heart that becomes damaged is
the bone marrow into the damaged heart.
known as the myocardium. This is the
These specific types of cells are called stem
muscular middle layer of the wall of the
cells, which are undifferentiated cells that
heart that stimulates the heart contractions to
can develop into any type of cells in the
pump blood.
body. There are many types of stem cells in
When the heart suffers a myocardial the body. Some of these are: adipose derived
infarction, its pumping becomes weaker stem cells (ADSCs), cardiac stem cells
progressively and this opens the pathway for (CSCs), peripheral blood derived cells,
heart failure. Heart failure is a progressive embryonic stem cells (ES), and induced
disorder in which the heart can not pump pluripotent stem cells (iPS) (Mingliang
enough blood to meet the body’s demand. It 2009). The problem with these other types
is estimated that yearly17 million of the of stem cells is that either they cause an
people worldwide die of cardiovascular adverse effect on the heart, or that they can
diseases, specifically heart attacks and not be used because of ethical
strokes . Despite advances in medicine, there considerations. Bone marrow derived cells
are currently no approaches in clinical (BMC) are currently the most widely used in
practice that replace myocardial scar with clinical trials because they are not as
functioning contractile tissue (Yeghizarians controversial and are the ones that exhibit
2009). the desired effect (Mingliang 2009).
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4. To prove that the BMC therapy would affected myocardium and that it attracts
improve the condition of the heart, scientists stem cells to that area to promote
in a research laboratory often induce heart reconstruction of myocardial growth
attacks on a mouse or rat model to study the network (Hoeben 2004). VGEF can increase
therapy. The way they do this is by placing a permeability of capillary wall, activate
ligature around a major blood vessel matrix metalloproteinase, and promote
connected to the heart muscle. This deprives endothelial cell proliferation and migration
the cardiomyocytes of their oxygen causing (Mingliang 2009). The therapy consists on
the heart attack. One of the findings of the injecting the myocardium with VEGF to
scientists when they were using the mouse induce angiogenesis after intramyocardial
model was that the mice that received the transplantation. Researchers show that
transplanted cells survived in greater VEGF increases angiogenesis, has a longer
numbers than mice with heart attacks that duration, and is probably necessary for the
did not receive the mouse stem cells preservation of the myocardium and
(National Institute of Health). limitation of cellular destruction when the
cells are deprived of oxygen (Hoeben 2004).
How is Vascular Endothelial Growth
In other words, VGEF helps improve
Factor (VGEF) Related to Cardiac
myocardial ischemia because there is an
Repair?
important relationship between VGEF,
VGEF is a molecule that has been found angiogenesis, and recovery for cardiac cell
to be an inducer of Angiogenesis, which therapy (Payne 2007).
indicates wound healing. Scientist believe
that VGEF molecule is secreted after
myocardial infarction in the region of the
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5. What Are the Effects of Drug Discussion:
Combination Therapy on Infarcted
There seems to be many new ideas
Hearts?
involving BMC therapy along with other
This type of therapy consists on the factors on how to treat heart diseases such as
administration of drugs to a patient after myocardial infarctions, but some of them
suffering from myocardial infarction. There still need to be further tested for
are many types of drugs that can be applied, consistency. Even though tests have shown
an example would be statins. Statins lower their effectiveness on mouse models and
plasma cholesterol by blocking the action of patients, it cannot be concluded that BMC
a chemical in the liver that is necessary for transplantation will cure heart failure. Some
the production of cholesterol (Ramasubbu of these ideas include the combination of
2008). The use of these types of drugs drugs right after the BMC transplantation, or
lowers the risks of heart attacks and strokes. the intravenous delivery of VEGF-A, which
In addition to inhibiting myocyte showed a significant improvement (Hoeben
hypertrophy, statins affect myocardial 2004). VEGF-blocking therapy appears
fibrosis (Ramasubbu 2008). Yang et.al used promising in the treatment of cancer,
simvastatin in the combination therapy and although, the clinical trials are still at an
obtained very good curative effects. Other early stage, and combination therapy seems
scientists have used different drugs such as more effective because both endothelial cell
angiotensin converting enzyme (ACE) and tumor cell are targeted.
inhibitor after an infarction and have
In conclusion, transplanting bone marrow
obtained similar results on the regeneration
stem cells to the damaged heart has been
of the myocardium.
proven to give beneficial results, but is even
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6. more effective when it is combined with Vascular Endothelial Growth Factor,
Angiogenesis, and Cardiac Repair After
vascular endothelial growth factor therapy Muscle Cell Transplantation into Ischemic
Hearts.[Internet]Cited November 15, 2011.
or drug combination therapy. It has opened
- Sambasiva K. R. S., Ananda K., Sai K,
the pathway for new myocardial infarction
Berrocal Ruben, Rao K.S.April 3, 2011.
treatments that will make an improvement Myocardial infarction and stem
cells.[Internet]Cited October 7, 2011.
on society.
- Strauer Bodo et.al. Regeneration of
Human Infarcted Heart Muscle by
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