The musical, Damn Yankees, explains it
best with the song, “You Gotta Have Heart”. The men’s Duke
basketball team is on a two game losing skid of which has not been seen in the past 3 years!
After relinquishing halftime leads in the past two games and losing by substantial amounts in the end, most fans are
critical of the team’s resilience. No one can deny the talent and athleticism
of this year’s squad, but many feel this team does not have the mental strength and heart of the teams which have characterized
Duke championship basketball over the past decade. The heart of our team has
been shattered, and we must find some way to rebuild it, or else we may be destined for a year of mediocrity.
Thus, I propose we follow the guide of our friend,
the zebrafish.
I
know what you’re thinking, but no, I have not been sniffing any glue. In
actuality, the zebrafish could truly hold the secret to our team’s success; for it is this fish that has just been discovered
to be able to regenerate its own heart muscle. We must embrace this fish and
study its lessons if we are to snap out of this uncharacteristic losing streak.
Within
the past year (Nov. 2002), researchers in the Department of Cell Biology and Department of Cardiology at Harvard Medical School
have found a gene that enables the zebrafish to repair up to 20% of its original heart muscle (Poss, Wilson, Keating, 2002,
p. I). Scientists did not simply stumble onto this discovery by mere chance. They already knew that zebrafish could regenerate their spinal cords, retinas, and
fins, and therefore hypothesized that the zebrafish may be able to regenerate heart muscle.
While such cardio reparatory genes have been found in invertebrate organisms (planarians, flatworms, or Hydra
polyps), the zebrafish is the first vertebrate to show signs of being able to rebuild heart muscle without substantial scarring. Most organisms (almost all vertebrates) simply scar over the area of the damaged heart
muscle rather than regenerate damaged tissue, as the zebrafish has found to be able to do.
Such a breakthrough in the field of heart regeneration research could lead to greater advances in the arduous battle
against heart disease.
Mark
T. Keating, a Howard Hughes Medical Institute investigator, helped head up the zebrafish heart regeneration experiment and
produced the findings of the study in the magazine, Science (Howard Hughes Medical Institute [HHMI], 2002). In the experiment, he and a group of fellow scientists surgically removed 20% of a few 1-2 year old zebrafish
hearts, and monitored the fishes’ heart repair over the next two months. In
the beginning it appeared as if the hearts would simply scar over the damaged heart muscle, but between the 9th
and 30th day, there were some signs of heart tissue growth, and by the 30th day, a “contiguous
wall of muscle had formed in the surgically altered hearts” (Gordon, 2002, p. 1).
By the 60th day, the hearts were fully repaired with minor or no scarring.
Additional tests identified that Mps1, a gene that serves as the blueprints for a protein which enhances critical cell
growth within damaged zebrafish fins and hearts, when mutated and exposed to temperatures above 33 degrees Celsius, no longer
functioned properly and could not regenerate damaged heart muscle (HHMI, 2002). Instead,
the damaged area of the heart simply scarred over.
This
information led Keating and fellow colleagues (2002) to a very interesting hypothesis; he claims that cell growth is essential
for regeneration, and even more importantly, there is constant competition between regeneration and scarring in most if not
all organisms (p. III). Keating further interpreted this finding to explain that
such a competitive situation between regeneration and scarring could be at work within the human heart, as well. This led Keating et al. to propose that perhaps one day we can enhance the “regenerative
potential in humans” (HHMI, 2002) so that regeneration will overcome scarring within human heart tissue. Keating says about the magnitude of this discovery, “The zebrafish could take this field of research
out of the Dark Ages” (HHMI, 2002). With the magnitude of heart disease
in today’s society, this zebrafish heart regeneration study is a step in the right direction towards further insight
into repairing damaged heart muscle. Mps1, the cell-cycle regulating gene discovered
to affect heart regeneration within the Zebrafish, gives scientists a strong starting point at where to begin and continue
field research on heart regeneration within humans. The ultimate goal of this
research is that one-day scientists will be able to identify and modify the genes responsible within the human body for heart
regeneration, and heart disease will become a horror of the past.
As for Duke basketball’s future success,
I recommend that the team should buy themselves a couple of zebrafish and ask them to regenerate some heart for the team so
that Duke basketball can get back on the winning track. If not, maybe we should
just throw the zebrafish out on the court and hope for the best.
More
information on heart regeneration studies within zebrafish can be found in Science Magazine or at the website: http://www.sciencemag.org/cgi/content/full/298/5601/2188
References
1. Gordon, Serena. Heart Regeneration Proved Possible. 12/12/2002. Health on the Net
Foundation.
1/25/2003. <http://www.hon.ch/News/HSN/510777.html>
2. Zebrafish May Point the Way to Mending a Broken Heart. 12/13/2002.
Howard
Hughes
Medical Institute. 1/25/2003. <http://www.hhmi.org/news/keating5.html>
3. Kenneth Poss, Lindsey Wilson, Mark Keating. (2002) “Heart Regeneration in
Zebrafish.”
Science. 298 (5601): 2188-2190.
<http://www.sciencemag.org/cgi/content/full/298/5601/2188>
