Muscle Stem Cells, Ethics and Exercise Sciences?
Q: Could you
highlight both Pro and Con arguments while examining ethical theories,
moral principles, and exercise related components pertinent to the
future of health and disease?
A:
Muscle stem cells, although banned in many countries and controlled by
others, has incredible hope to decrease human suffering. The issue of
human stem cell use to assist in tissue repair and regeneration has
very significant implications for muscle repair following
exercise-induced damage, injury, and disease. Injecting stem cells
directly into the tissue, would assist the 'endogenous' stem cells,
satellite cells, in the muscle repair and regeneration process, or
perhaps replace several defective cells, as seen in diseases such as
muscular dystrophy. Evidence shows that several different cell types of
nonmuscle origins can give rise to muscle cells in vivo, including
connective tissue cells, myofibroblasts, and vascular endothelial cells
(Grounds 2000).
There
has been a tremendous amount of interest in investigating the
contribution of various muscle stem cell populations in regenerating
skeletal muscle. It is well established that the myogenic progenitor
cells, also known as muscle satellite cells, which are largely
responsible in the formation of muscle strength and hypertrophy (Hawke
2005), in addition to repair of muscle. Moreover, these satellite cells
fuse to existing myofibrils (muscle cells) by donating their nuclei,
thereby enhancing regeneration, and a formation of a new myofiber.
Therefore, this process is increased primarily during the recovery
period of exercise involving strength training.
Using
human embryos to gain potential for human life raises more questions
than answers. Ethical principles and morality play a pivotal role in
determining the future of humankind. Does such a tiny cell deserve the
same moral and status of a living, breathing human? Is it ethically
sound, and what are the important connections for future disease and/or
disability? This article will highlight both Pro and Con arguments
while examining ethical theories, moral principles, and exercise
related components pertinent to the future of health and disease.
Pro
Human
muscle stem cells are early "universal" cells with the potential to
form virtually any somatic cell (any cell forming the body of an
organism) in the human body (Jungest 2000). If research continues,
scientists could be able to differentiate those universal cells into specific types, such as the
emergence of new neurons (nerve cells) responsible for
neurodegenerative diseases like Parkinson's disease and Alzheimer's
disease, in addition to new pancreatic cells for diabetic patients, and
innovative cardiac muscle for hearts (Wright 1999). Wright
(1999) also explains the notion that human stem cells "could be grown
as universal graft tissue for blood, bone marrow, lung, liver, kidney,
tendons, ligaments, muscle, skin, hair, teeth, the retina and lens of
the eye; the possibilities are endless" (pg 361). It seems that stem
cells promise revolutionary advances to science and technology that
help alleviate human suffering. However, many governments hamper it
with via strict regulations or even banning it completely.
Interestingly
in the United States, there is a broad ban on federal funding for human
stem cells, unless federally stem cell lines are used (Drazen 2004) As
emphasized in the editorial in Lancet (2004), "banning this work will
deny thousands of individuals the chance to live a comfortable life"
(pg 113-14).
Many
ethical questions must be discussed from multiple view points and
theories in order to understand keys concepts of human stem cells. For
example, will it help more people than it hurts? Is it for the greater
good? Is it really a person or just a life form? Although there may not
be an absolute answer, we can discuss these from various ethical
perspectives. One approach is to do what is morally right because it is
right, regardless of any developing consequence(s), hence the
deontological approach. The other is to maximize good and minimize harm
so the greatest possible good is attained for the greatest number of
people, hence the Utilitarian approach. However, a confounding ethical
issue of the deontological method is: Is it right to use human stem
cells, which offers enormous capabilities for human life, with no
regard to that potential? In contrast, the Utilitarian approach is: are
we obligated to do whatever is necessary to ease the millions of people
who are suffering? Appreciably, understanding moral principles is
crucial for the understanding of the human stem cell. From a Divine
Command approach, God created man, and if God commands it, then it is
right. Therefore, we have every right to create cloned embryos and stem
cells as well.
The
question is whether a human embryo constitutes a human person.
According to Kant's theory we should always treat people as ends and
not means to an end. However, we at times, use people as means, but we
should acknowledge their dignity as human beings.
Practically,
this means using human subjects for research protocols, but only after
informing them concerning potential benefits and/or risks, and
following the informed consent process. Subsequently, does this apply
to the human stem cell? If we determine the human embryo is a person,
then yes, it has all the same rights that living, breathing humans
have, and we should give equal importance and treatment to that human.
However, if they do have moral status, there may be limitations on how
we treat them. Specifically, the limitations on how embryos are
created. Therefore, research must consider any alternatives and their
potential benefits.
Con
With
the present state of technology, it helpful to point out the creation
of a human embryonic stem cell line requires the destruction of a human
embryo. Here in lies the main argument against stem cell research.
First, embryonic stem cell research infringes upon and violates the
sanctity of life and is therefore equal to that of murder. Second, the
fundamental assertion of those who oppose embryonic stem cell research
is the belief that human life is unbreakable and resilient, due to the
fact that human life begins at conception. In contrast with the Pro
side, some believe embryos are not humans, that the life of Homo
sapiens only begins when the heartbeat develops, which is during the
5th week of pregnancy, or when the brain begins developing activity,
which has been detected at 54 days after conception. (Singer 1996).
According
to Kant's theory of human dignity, it would immoral to harm or violate
in any shape or form something that has potential for human life, even
though it may alleviate the suffering of millions. From this approach,
the embryo, thus stem cells have no moral status or significance.
Therefore, we are not obligated to provide any special consideration,
and are open to do whatever we want.
In
addition, one ethical dilemma concerning stem cell research is the
merging of embryonic stem cell and cloning technologies, "leading to
generation of an embryo that is a genetic clone of the donor of the
nucleus" (Biotechnologies online 2005). Along these line is the use of
stem cells to generate tissue for transplantation. The individual's
immune system would detect these cells as invaders and attack, and the
insufficient immune response would pose a threat in all transplant
therapies (Biotechnologies online 2005).
Assuming
that it is morally wrong to destroy human embryos, based on the
discussion above, are stem cell researchers morally responsible for the
destruction of embryos engaging in a wrong act? One response is that a
"researcher who benefits from the destruction of embryos need not
sanction the act any more than the transplant surgeon who uses the
organs of a murder or drunken driving victim sanctions the homicidal
act" (Curzer 2004).
References
1).
Grounds, M.D, White, J.D; Rosenthal. N; & Bogoyevitch. M.A. (2002).
The role of stem cells in skeletal and cardiac muscle repair. Journal
of Histochemistry and Cytochemistry. 50(5):589-610. Review
2). Hawke, T.J. (2005). Muscle stem cells and exercise training. Exercise and Sport Sciences Reviews, 33(2):63-8. Review
3).
Juengst, E. & Fossel. M. (2000). The ethics of embryonic stem
cells--now and forever, cells without end. Journal of American Medical
Association, 27; 284(24):3180-4.
4). Wright, S.J. (1999). Human embryonic stem cell research: science and ethics. American Scientist. 87:352-361
5). Drazen JM. (2004). Embryonic stem-cell research--the case for federal funding.New England Journal of Medicine. 21; 351(17):1789-90.
6). Singer, Peter. (1996). Rethinking life & death: the collapse of our traditional ethics. St. Martins Press.
7). Biotechnologies Online (2005). Ethics in Stem Cell Research. http://www.biotechnologyonline.gov.au/human/ethicssc.cfm
Jonathan Mike, MS, CSCS, USAW, NSCA-CPT,
Doctoral Student, Assistant Editor