Mitochondria Man

Dr. Shoukhat Mitalipov in his office. / Photo by Joni Kabana

Shoukhrat Mitalipov is a molecular biologist at OHSU’s National Primate Research Center in Beaverton. Recently, he announced, through the science journal Nature, breakthrough research in which he created mitochondrial disease-free monkey offspring by replacing the diseased parental mitochondria with disease-free donor mitochondria. The upshot of Dr. Mitalipov’s research could help parents have their own biological children without the risk of inherited mitochondrial diseases. That’s huge. At least one in 200 born childen inherits mitochondrial mutations that can lead to disease. The problem now is navigating political and regulatory barriers in the U.S., while the U.K. embraces Mitalipov’s research.

Tell me about your academic background in the former Soviet Union.

I received my PhD degree from the Research Center for Medical Genetics in Moscow, Russia. My area of research expertise is within reproductive, embryo and stem cell biology.

What are some common problems that reproductive science has cured since it began?

Currently, reproductive science is focused on understanding the biology of reproduction that begins with the development of egg and sperm, and ends with birth and the nursing of infants. In the medical field, reproductive science develops reliable contraceptives, novel treatments of infertility, and therapeutics for disorders associated with pregnancy and perinatal health. For example, assisted reproductive technologies (including in-vitro fertilization, or IVF) are used to achieve pregnancy by artificial or partially artificial means in infertile patients. It is reproductive technology and used primarily in infertility treatments.

In layman’s terms, tell me about the goals of your research.

I am particularly interested in inherited human diseases and ways to prevent transmission of faulty genes causing these diseases—from parents to their children. Our goal is to develop novel gene and stem cell therapies for treatment of currently incurable human diseases.

In 2009, you broke a scientific barrier by transferring mitochondrial genes (DNA) from a monkey egg to another host egg whose mitochondrial DNA had been removed and, in the end, created healthy offspring, Mito and Tracker. What are the human implications for this type of gene transfer?

Mutations in mitochondrial genes contribute to a diverse range of devastating human diseases, and it is estimated that at least one in 200 born children inherit such mutations that may lead to a disease. Since mitochondrial genes are maternally inherited through the egg’s cytoplasm, our discovery suggests that the mitochondrial DNA from a patient’s egg containing any mutations could be removed, and replaced with normal mitochondrial genes donated by a healthy woman. A child born after in-vitro fertilization with the husband’s sperm would be free of risk from maternal mitochondrial DNA mutations and be the authentic biological child of the parents.

What are some typical mitochondriabased diseases?

Mitochondrial diseases result from failures of the mitochondria—a specialized organelle present in every cell of the body—to produce energy needed to sustain life and support growth. As a result of this dysfunction, less and less energy is generated. That leads to cell, tissue and organ injury and eventually to death. Diseases of the mitochondria appear to cause the most damage to organs requiring the most energy such as brain, heart, liver, skeletal muscles, kidney, endocrine and respiratory systems. Therefore, depending on which organs are first affected, symptoms may include loss of motor control, muscle weakness and pain, gastro-intestinal disorders and swallowing difficulties, poor growth, cardiac disease, liver disease, diabetes, respiratory complications, seizures, visual/hearing problems, lactic acidosis, developmental delays and susceptibility to infection. The mitochondrial diseases also primarily affect children, but adult onset is becoming more common.

What therapies do you envision coming out of this process? How is that different from the widely embraced in-vitro fertilization?

Since many of these conditions are inherited from mothers’ mitochondrial DNA, I believe we should be able to correct these gene mutations in an egg, even before an embryo is created. Parents suspected of having such mutations would undergo an in-vitro fertilization procedure, where we recover their eggs and sperm. Then we replace mutated mitochondrial genes in eggs with donated healthy genes. Eggs would then be fertilized with the man’s sperm and embryos transplanted back into the woman to initiate pregnancy, just like a regular IVF treatment. Our technology is based on conventional in-vitro fertilization procedures but used not for treatment of infertility, rather as a gene therapy to prevent inherited diseases.

The international science journal Nature recently reported that the U.K. is investing more than $8 million in a clinic that will begin clinical trials on humans using your research. Why there and not here?

The U.K. pioneered IVF treatments in the 1970s and favorably accepts any new developments in this field. Various U.K. governmental, regulatory and funding agencies seriously reviewed our discovery since its publication in 2009 and concluded that the procedures are safe and efficient. They recommended some additional studies with human eggs that would be needed before clinical trials could begin and allocated funding to support these studies in the U.K. This shows how scientists, lawmakers and ethicists could come together and synchronize their efforts to make the U.K. the first country to apply our techniques to treat patients. Unfortunately, the U.S. is lagging in this field. One reason is that federal regulations restrict clinical research by not allowing any federal funding for human embryo and stem cell research. This unfortunately means that we will not be able to conduct clinical trials in order to eventually offer these medical treatments to our patients in the U.S.

Are we letting other countries eat our lunch by not commercializing our own embryonic research?

It looks like it’s going that way. However, we (OHSU) hold a patent on this technology. I am hoping that we will be able to attract private funding as well as venture capital to support clinical trials here and commercialize our own intellectual property.

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