According to the World Health Organization, approximately 17.9 million people worldwide die from cardiovascular disease each year. It is the leading cause of death, responsible for about one out of every three deaths globally. Scientists around the world are continuously striving to better understand the underlying causes of cardiovascular disease and find better methods of prevention and treatment.
To further advance their cardiovascular research, many researchers are taking their studies out of this world—to the International Space Station (ISS) U.S. National Laboratory. The microgravity environment of the ISS allows scientists to study cells and tissues in ways not possible on the ground.
Below highlights some of the ways the ISS National Lab is being leveraged for valuable cardiovascular research to help improve the lives of the millions of people on Earth with cardiovascular disease.
Examining Microgravity’s Effects on Heart Function
A team of researchers from Stanford University led by Joseph Wu used the ISS National Lab to study the effects of microgravity on cardiomyocytes (specialized heart muscle cells) derived from human induced pluripotent stem cells (iPSCs). To develop iPSCs, scientists alter human blood or skin cells to reinstate characteristics of natural stem cells. In their investigation, Wu and his team examined microgravity-induced changes in the contraction, growth, and gene expression of the cardiomyocytes. Insight gained from this research could help scientists better understand the mechanisms behind heart muscle cell function. Such knowledge could enable improved cardiovascular disease modeling and drug testing and lead to the development of therapies to treat damaged heart muscle cells.
Wu and his team are planning to conduct a second investigation on the ISS National Lab looking at microgravity’s effects on heart function using 3D-engineered heart tissue derived from iPSCs. The team aims to determine whether microgravity’s effects on the engineered heart tissue mimic characteristics of ischemic cardiomyopathy, a condition in which heart muscles are weakened due to heart disease or a heart attack. In the future, the team hopes to use the engineered heart tissue in microgravity to screen potential new drugs to treat heart conditions on Earth.
Evaluating Microgravity-Induced Changes in Immature Heart Cells
Loma Linda University researcher Mary Kearns-Jonker and her team used the ISS National Lab to study the effects of microgravity on human cardiovascular progenitor cells (CPCs). CPCs are cells at a very early stage of development that can differentiate into different types of cardiovascular cells, such as heart muscle cells or the cells that line blood vessels. This investigation looked at both neonatal CPCs (from newborns) and adult CPCs and compared CPCs grown on the ISS National Lab with ground controls. Kearns-Jonker and her team analyzed the cells’ gene expression and their ability to divide, move, and communicate via signaling. The team found that microgravity induces changes in CPCs that could be beneficial for cell-based regenerative therapies back on Earth.
Kearns-Jonker was presented with the 2018 International Space Station Compelling Results Award in Biology and Medicine at the ISS Research and Development Conference for her compelling research on CPCs that could have a significant impact on the development of therapies to repair damaged heart tissue. Read more in this ISS360 article.
Growing 3D Clusters of Mature Heart Cells Derived From Stem Cells
A group of University of Houston researchers led by Robert Schwartz used the ISS National Lab to grow 3D clusters of mature heart cells from CPCs that were derived from mesenchymal stem cells, which come from bone marrow. In microgravity, cells form into complex 3D structures that more closely resemble tissues in the human body. This investigation follows from a ground-based experiment that examined how simulated microgravity affects two critical genes involved in reprogramming fibroblasts (a type of connective tissue cell) into CPCs and the formation of mature heart cells into 3D clusters. Results from this research could help advance the development of regenerative therapies for cardiac repair.
Studying Heart Cell Proliferation and Differentiation in Microgravity
In an upcoming flight project, a research team led by Chunhui Xu at Emory University School of Medicine seeks to evaluate how microgravity affects the ability of CPCs derived from iPSCs to proliferate (divide and increase in number) and differentiate into cardiomyocytes. This research builds on a ground-based investigation in which the team used simulated microgravity to increase the yield, purity, and survival of cardiomyocytes derived from iPSCs. True microgravity conditions on the ISS National Lab are expected to further enhance these effects. The research team hopes to gain a better understanding of cardiomyocyte differentiation, which could lead to advances in regenerative medicine and the development of heart tissue for improved disease modeling and drug testing.
Understanding Mechanisms Behind Cardiovascular Disease
In an investigation planned for launch in the coming months, a research group at the University of Florida led by Josephine Allen aims to use the microgravity environment of the ISS National Lab to elucidate the molecular mechanisms behind vascular cell damage. Spaceflight causes changes in the human body that affect the cardiovascular system and increase the risk of cardiovascular disease. Dysfunctional vascular cells are a major contributing factor in cardiovascular disease, and by studying vascular cells in microgravity, the research team hopes to better understand the underlying mechanisms involved in damage to the cells. The team will analyze genetic changes that occur in the spaceflight cells compared with ground controls. Knowledge gained from this investigation could lead to new lines of research and new potential treatment options for people with cardiovascular disease.
Developing a Tissue Chip to Model Cardiac Dysfunction
In another upcoming investigation, a team of researchers from the University of Washington led by Deok-Ho Kim aims to develop a tissue chip system to grow human cardiac muscle tissue derived from human iPSCs. Tissue chips are small chips containing human cells grown on an artificial scaffold to model the detailed structure and function of human tissue. The team will use the tissue chip system to examine the effects of microgravity on cardiac tissue structure and physiological function. Knowledge gained from this research could help provide a better understanding of cardiac dysfunction. In the future, the tissue chip system could be used to study the progression of heart disease and to screen novel drugs to treat heart conditions on Earth. This project builds on a previous ISS National Lab investigation that studied microgravity’s effects on heart cells derived from human iPSCs.
Learn more about these and other ISS National Lab investigations in the related links below.