Sharon Gerecht, an assistant professor of chemical and molecular engineering in the university’s Whiting School of Engineering, recently received a $150,000 two-year grant from the March of Dimes Foundation to support her research; earlier, she received a $310,000 four-year award from the American Heart Association to advance this promising line of study.
Gerecht is using the funds to answer important questions about what happens at the molecular level when stem cells differentiate: Which environmental cues cause them to form blood vessels instead of other types of body tissue? Is it a lack of oxygen? Is it the nutrients on which the cells feed? Is it the texture and composition of the material on which the cells are situated? And which type of stem cells is best-suited to the assembly of replacement blood vessels?
Solving these puzzles, Gerecht said, should help her and other researchers to more effectively harness the power of stem cells for human health remedies.
“Stem cell research has generated lots of excitement because it has so much potential to help so many people who are ill or injured,” she said. “But we don’t have a very good understanding of what’s going on when stem cells change into a certain type of tissue, and we can’t control the transformation with much precision. We’re trying to learn more about what causes these cells to develop and differentiate. With this knowledge in hand, we can make medical applications involving stem cells more successful and more reliable.”
To look for these answers, Gerecht, recipient of the 2008 Maryland Outstanding Young Engineer Award, is using engineering techniques to manipulate the environment in which stem cells are placed. These lab experiments are aimed at finding just the right molecular signals that will cause stem cells to form blood vessel networks.
One of these environmental factors is the amount of oxygen to which the stem cells are exposed. Reducing the oxygen these cells require creates a condition called hypoxia. “We are trying to mimic this condition in the lab,” Gerecht said, “because some research indicates that a lack of oxygen causes stem cells to form blood vessels in order to deliver more oxygenated blood to affected areas of the body. We are using our engineering approach to find out if this is actually what happens.”
The research is important because the cardiovascular network is one of the earliest differentiating and functioning systems in human embryos. The March of Dimes Foundation, which focuses on preventing birth defects, premature births and infant mortality, awarded its grant to Gerecht to study the role of hypoxia during vascular development of human embryonic stem cells. The experiments will be conducted with National Institutes of Health-approved embryonic stem cell lines. Embryonic stem cells can be made to reproduce in the lab with relative ease, Gerecht said, but it is difficult to control the differentiation of these blank-slate cells toward a specific function, such as forming blood vessels.
With support from her American Heart Association grant, the Johns Hopkins researcher is trying to determine if adult stem cells are better candidates. It is easier, Gerecht said, to direct certain adult stem cells to become the building blocks of new blood vessels. They possess another advantage: If the adult cells are taken from the patient who will ultimately receive the treatment, tissue rejection is unlikely. But adult stem cells have drawbacks as well: They are more difficult to isolate and cannot easily be made to multiply in the lab.
Gerecht also hopes to experiment with a third type that has recently attracted attention: induced pluripotent stem cells. These are adult cells that have been reprogrammed through gene manipulation to behave more like embryonic stem cells.
Major hurdles and years of additional research remain before the replacement tissue Gerecht is trying to develop may be used to restore healthy blood flow in humans. In addition to selecting the right type of stem cells and the proper growth environment, she must find the best way to persuade the cells to form the proper three-dimensional shape of living blood vessel networks. “To be able to do that,” she said, “we need to understand much more about the underlying molecular events. Then, we can manipulate these events to get the new blood vessels that we want.”
To advance her research, Gerecht has been collaborating with experts from elsewhere in the university, including Gregg Semenza and Linzhao Cheng from the School of Medicine’s Institute for Cell Engineering. She has also worked with Whiting School of Engineering colleagues Denis Wirtz, a professor of chemical and biomolecular engineering, and Hai-Quan Mao, an assistant professor of materials science and engineering. Gerecht, Semenza, Wirtz and Mao also are affiliated with the Institute for NanoBioTechnology at Johns Hopkins.
Gerecht earned her doctorate in biotechnology at the Technion in Israel. She then continued her research in the United States, spending three years as a postdoctoral fellow at MIT. She joined the Johns Hopkins engineering faculty in 2007.
Color images of Sharon Gerecht and her lab team available; Contact Phil Sneiderman.Related Links:
Phil Sneiderman | Newswise Science News
Seeing on the Quick: New Insights into Active Vision in the Brain
15.08.2018 | Eberhard Karls Universität Tübingen
New Approach to Treating Chronic Itch
15.08.2018 | Universität Zürich
Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.
When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...
Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.
Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....
Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.
Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...
Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur
What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...
The quality of materials often depends on the manufacturing process. In casting and welding, for example, the rate at which melts solidify and the resulting microstructure of the alloy is important. With metallic foams as well, it depends on exactly how the foaming process takes place. To understand these processes fully requires fast sensing capability. The fastest 3D tomographic images to date have now been achieved at the BESSY II X-ray source operated by the Helmholtz-Zentrum Berlin.
Dr. Francisco Garcia-Moreno and his team have designed a turntable that rotates ultra-stably about its axis at a constant rotational speed. This really depends...
08.08.2018 | Event News
27.07.2018 | Event News
25.07.2018 | Event News
15.08.2018 | Physics and Astronomy
15.08.2018 | Materials Sciences
15.08.2018 | Life Sciences