APPLICATION OF STEM CELLS IN ISCHEMIC HEART DISEASE - Micro and Nanotechnologies in Engineering Stem Cells and Tissues - page 262

recently, reperfusion of the ischemic myocardium was the only intervention availa-
ble to restore the various cellular functions affected by myocardial ischemia,
including preventing cell death by necrosis or apoptosis. Unfortunately, reperfusion
may result in extensive myocardial damage, including myocardial stunning, and the
functional recovery of the heart may appear only after a period of cardiac contractile
dysfunction that may last for several hours or days. It is evident that the limited
capacity of regeneration and proliferation of human cardiomyocytes can prevent
neither the scar formation that occurs after myocardial infarction (MI) nor the loss of
heart function occurring in patients with cardiomyopathy and heart failure. Replace-
ment and regeneration of functional cardiac muscle is an important goal that could be
achieved either by stimulation of autologous resident cardiomyocytes or by the
transplantation of allogenic cells (e.g., embryonic stem cells, bone marrow mesen-
chymal cells, or skeletal myoblast). 1-24
The discovery of cardiogenesis in adult animals and human represent one of the
most significant advances in cardiology in the past 25 years (Table 12.1). Previously,
most cardiologists believed that the birth of new cardiomyocytes was only confined to
the fetal and neonatal heart. This dogma recently collapsed when researchers dis-
covered that the hearts of adult rats, mice, and humans undergo significant cardiac
TABLE 12.1 Major Milestones in Stem Cell Research
1981. First mouse embryonic stem cell (ESC) lines isolated and grown in culture
1981. First transgenic animals produced
1988. First cord blood transplant
1989. A clonal line of human embryonal carcinoma cells derived
1990. Britain passes the Human Fertilization and Embryology Act
1994. Human ES-like cells generated
1995. Evidence found for neural stem cells
1996. Dolly, the first cloned sheep, born in Scotland
1998. Scientists at University of Wisconsin-Madison and Johns Hopkins University isolated
the first human stem cells
2000. Scientists in Singapore and Australia derive human ESCs from blastocysts
2001. Advanced Cell Technology creates the first cloned human embryos
2001. U.S. President George Bush blocks federal funding for creation of new stem Cell lines
2001. Human ESCs successfully developed into blood cells
2002. Neural stem cells successfully developed into functional neurons
2003. Institute of Stem Cell Research, Edinburgh, discovers key gene that keeps ESCs in a
state of youthful immortality
2003. Dolly dies after developing progressive lung disease
2003. UK Stem Cell Bank established
2004. Web-based resource for international stem cell researchers launched
2004. Californians approve Proposition 71 to spend $3 billion over 10 years on stem cell
research
2005. U.S. House of Representatives approves a bill to loosen restrictions on federal funding
for stem cell research
2006. Judge rules in favor of proceeding with the financing of California's 10-year stem cell
project (based on Proposition 71)