Healthy brain, muscle, eye and heart cells would improve the lives of tens of thousands of people around the world with debilitating mitochondrial diseases. Now, researchers at the Salk Institute have gotten one step closer to making such cures a reality: they've turned cells from patients into healthy, mutation-free stem cells that can then become any cell type. The new approach is described July 15, 2015 in Nature.
"Right now, there are no cures for mitochondrial diseases," says senior author Juan Carlos Izpisua Belmonte, professor in Salk's Gene Expression Laboratory. "Very recently, we've developed ways to prevent these diseases, so it was natural to next ask how we could treat them."
Mitochondrial diseases are caused by any of about 200 mutations that affect the genes of mitochondria, tiny powerhouses inside nearly every cell of the body. Depending on the affected genes and cell types, the diseases can cause muscle weakness, liver disease, diabetes, seizures, developmental delays or vision problems. Existing therapies aim to ease the symptoms or slow the progression of the diseases, but can't entirely cure them.
In their new work, Belmonte and collaborators from around the world collected skin samples from patients with mitochondrial encephalomyopathy or Leigh Syndrome, both severe disorders that affect the brain and muscles.
The teams began by using current standard protocols to derive pluripotent stem cells from the skin cells, a process that resets the cells to their most basic state.
"During the process of stem cell generation, you spontaneously get different types of clones," says Alejandro Ocampo, a research associate in Izpisua Belmonte's lab and one of the authors of the new paper. If the patient cells have an initial mix of healthy and diseased mitochondria, healthy and diseased stem cells will be generated. Then, the stem cells with healthy mitochondria can be picked out.
For some patients, though, this straightforward approach doesn't work; their cells don't have enough--or any--healthy mitochondria to start with.
So the team came up with a second approach: move the nucleus of the patient's skin cells, which contains most of their genes, into a donor egg cell with healthy mitochondria. Then, use the new egg cell to generate pluripotent stem cells. When the researchers did this, they found the healthy mitochondria took over, and healthy, genetically similar cells from the patient were successfully generated.
"In either case, the idea is that we have healthy stem cells, and we know how to convert pluripotent stem cells into different cell types," says Jun Wu, an author of the paper and research associate in Izpisua Belmonte's lab. "They have the potential to give rise to every cell type in the body."
For now, that means that researchers can use the healthy cells to generate heart, brain, muscle or eye cells from the mutation-free stem cells. But methods to make those cells fully mature and functional and transplant them into patients are still under development.
The new method will also be a boon to basic research, Izpisua Belmonte adds. Scientists have long struggled to understand why different organs and tissues are affected so differently by mitochondrial mutations. By comparing stem cells with mitochondrial mutations with healthy ones, and coaxing each to develop into different cell types, they can study this aspect of mitochondrial diseases in more detail.
Other researchers on the study were Li Ma of the Salk Institute; Hong Ma, Riffat Ahmed, Eunju Kang, Yeonmi Lee, Tomonari Hayama, Ying Li Crystal Van Dyken, Nuria Marti Gutierrez, Rebecca Tippner-Hedges, Amy Koski, Nargiz Mitalipov, Paula Amato, Don P. Wolf, and Shoukhrat Mitalipov of Oregon Health & Science University; Clifford D. L. Folmes, and Andre Terzic of the Mayo Clinic; Robert Morey, Sergio Mora-Castilla, and Louise C. Laurent of the University of California, San Diego; Joanna Poulton of the University of Oxford; and Xinjian Wang and Taosheng Huang of Cincinnati Children's Hospital.
The work was supported by the G. Harold and Leila Y. Mathers Charitable Foundation and the Leona M. and Harry B. Helmsley Charitable Trust.
About the Salk Institute for Biological Studies:
The Salk Institute for Biological Studies is one of the world's preeminent basic research institutions, where internationally renowned faculty probes fundamental life science questions in a unique, collaborative and creative environment. Focused both on discovery and on mentoring future generations of researchers, Salk scientists make groundbreaking contributions to our understanding of cancer, aging, Alzheimer's, diabetes and infectious diseases by studying neuroscience, genetics, cell and plant biology, and related disciplines. Faculty achievements have been recognized with numerous honors, including Nobel Prizes and memberships in the National Academy of Sciences. Founded in 1960 by polio vaccine pioneer Jonas Salk, MD, the Institute is an independent nonprofit organization and architectural landmark.
Salk Communications | EurekAlert!
Researchers identify potentially druggable mutant p53 proteins that promote cancer growth
09.12.2016 | Cold Spring Harbor Laboratory
Plant-based substance boosts eyelash growth
09.12.2016 | Fraunhofer-Institut für Angewandte Polymerforschung IAP
Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.
Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
09.12.2016 | Life Sciences
09.12.2016 | Ecology, The Environment and Conservation
09.12.2016 | Health and Medicine