Sunday, May 18, 2014

Stem cell therapy regenerates heart muscle damaged from heart attacks in primates

Ronak Shah

No specific author given, but is from University of Washington

Published April 30, 2014

http://www.sciencedaily.com/releases/2014/04/140430133056.htm

Summary:

Dr. Charles Murray at University of Washington led a research team to conduct an experiment: Can human embryonic stem cells from muscle cells regenerate non-human primate hearts? To perform the experiments they preformed controlled myocardial infarctions in a type of old world monkey called a Macaque. The researchers blocked the coronary artery for 90 minutes to simulate the heart attack, because in humans, heart attacks most often occur from a block in the coronary artery. 2 weeks after the myocardial infarctions, researchers injected human embryonic heart cells into the infarcted (all monkeys were put on immunosuppressives to stop the rejection of the cells). The researchers found over the next weeks, the stem cells infiltrated the damaged tissue, then matured into muscle fibers, and then began to work in the monkey hearts. After three months, they were fully integrated. The cells regenerated 40% of the damaged heart tissue. Researchers say they now the scale and procedure for possibly trying this on humans, and may be able to come up with a new procedure. The most common complications were arrhythmias, a few weeks after the transplant, but these subsided after the electric signal became more stable and the arryhthimias subsided so researchers are very optimistic.

Connection:

This clearly connects to our studies in the circulatory system, stem cells, and the complications that can arrise in the two. We studied something called homeostasis, which is the bodies ability to maintain a stable inner environment. Myocardial infarction's impair this ability by killing the heart tissue, making the part of the heart not pump so some of the crucial tasks of the circulatory system, such as delivering oxygenated and deoxygenated blood, and fighting infection are impaired. This article provides a possibility for actually treating the damaged heart tissue, rather than just unblocking the artery, using stem cells. We studied stem cells earlier in the year when we talked about how they could specialized as they mature and turn into different kinds of cells depending on the environment. The heart stem cells will provide a way to return homeostasis to first the heart, then the circulatory system, and then finally the entire body.

Heart attack gene, MRP-14, triggers blood clot formation

Heart attack gene, MRP-14, triggers blood clot formation

Matthew He
5/18/14

Author: Case Western Reserve UniversityLink: http://www.sciencedaily.com/releases/2014/04/140401172910.htm

Summary: 
Scientists at Case Western Reserve School of Medicine and University Hospitals Case Medical Center have studied humans and mice and discovered how MRP-14 (myeloid related protein-14 ) generates dangerous clots that could trigger heart attack or stroke, and what happens by manipulating MRP-14. A whole new pathway was discovered that shows clotting platelets have MRP-14 inside them, that platelets secrete MRP-14 and that MRP-14 binds to a platelet receptor called CD36 to activate platelets. In detailed studies using MRP-14-deficient mice, the investigators discovered MRP-14 in action. A key fact is that, while MRP-14 is required for pathological blood clotting (Heart disease), it does not appear to be involved in the natural response to prevent bleeding. This is potentially groundbreaking because if a drug could be developed that stops pathological clotting without interfering with the body's natural clotting to heal cuts, you would have a safer medication to treat clotting for heart attack or stroke.

Impact: 
This article connects to the circulatory system, and in particular, pathological clotting. Pathological clotting is a major part of Atherosclerosis, and Myocardial Infarction. In the current class unit, we learned that the circulatory system's imbalances are often clot related, as clotting blocks the circulatory system's function of bringing oxygen and nutrients to cells. In addition, we learned about natural clotting with platelets and fibrin. This connects to pathology of the circulatory system because it identifies a specific gene that is involved with pathological clotting, showing that heart disease has genetic factors in it.