The remnants of ancient bacteria live inside each of us as mitochondria, structures in cells that are critical for life. Breakthrough work from Simon Johnson, B.S. biochemistry and biophysics ‘09, and his lab has shed new light on how dysfunction of mitochondria causes human disease.
Since receiving his bachelor’s at Oregon State, Johnson has gone from graduate school at the University of Washington in Seattle to completing a postdoc in human genetics at the Albert Einstein College of Medicine in New York. Following a short second postdoc at Seattle Children’s Research Institute, he went on to fulfill his goal of opening his own laboratory, which he now runs at Northumbria University in the U.K.
The desire to understand and solve the world’s problems through science has been a constant during his time in the field.
“One of the most important careers that you can do is to try to advance human knowledge,” he said. “What you learn over the years is that the most vital quality a student can have is passion.”
For his great strides towards a cure for mitochondrial diseases within a decade since his last degree, Johnson has received the 2023 Young Alumni Award in the College of Science.
More than the cell’s powerhouse
Academia has played a large role in Johnson’s career. Even with such a great amount of exposure, Oregon State remains a cherished part of his journey.
“I loved OSU. It’s a beautiful campus, it’s kind of an undiscovered gem. I’ve been all over the world and seen a lot of college campuses, and I think OSU is one of the best,” he said.
As a first year student, Johnson was eager to study as many branches of science as possible. This led him to choose the more interdisciplinary biochemistry and biophysics major. He eventually honed his interests down to biology, intrigued by what he considered to be the largest question in the field: Why do humans age?
The thought led him to attend graduate school at the University of Washington in order to study aging. There he found a new interest in mitochondrial disease, which has followed him through his career. It was only recently his research shocked himself and fellow scientists alike.
Many know the mitochondria as the powerhouse of the cell. They are multipurpose organelles found within animal and plant cells that are involved in many diverse functions, most notably generating energy for a cell to use.
Mitochondrial diseases are a particular challenge to study because of the wide breadth of genetic mutations that can trigger them. Not only are there over 250 known genetic causes, but the connections between mutations that incite similar diseases are often unclear. The sole mechanistic link across all genes that cause mitochondrial diseases is the products they create, which always circle back to the mitochondria.
The study of mitochondrial diseases has historically focused on the organelle’s role in generating energy. With recent work from Johnson’s lab, however, this approach may be about to change.
Because patients with the disease are typically born healthy and develop its symptoms later in life, Johnson explained, the idea of energy issues from mitochondria being the cause doesn’t align with the data. Instead, work in his laboratory led him to a different conclusion, one that involved the organelle’s origins.
“We’re at this very interesting intersection between immunology and neurobiology that nobody else has really been looking at for mitochondrial disease.”
Mitochondria originally arose from bacteria that entered eukaryotic cells and evolved into the modern structure found within every human today. Because of this, some bacterial components remain intact, such as marks in mitochondrial DNA that are specific to bacteria.
“If any of those things get out of the cell, they stimulate innate immune responses that have evolved against bacteria,” Johnson said. “All of our data is pointing that direction, that for whatever reason when disease sets in, brain cells are leaking some mitochondrial component that’s setting off an innate immune response.”
Following this breakthrough, his lab is focusing its research on identifying what components of mitochondria could be prompting an immune response. Given that the disease often targets the brain and is now tied to the immune system, Johnson’s research marries different branches of science and delves into largely uncharted waters in search of answers.
“We’re at this very interesting intersection between immunology and neurobiology that nobody else has really been looking at for mitochondrial disease,” he explained.
Despite this leap in progress, Johnson has no intention of slowing down. A year before earning the Young Alumni Award, he was offered to move his lab to the U.K. at Northumbria University and has since begun to settle down in his new home. His prospects for the future continue to be bright as he grows ever closer to the end of this multi-year research journey.
“I will love the point when we have cured this disease or come up with a final description of the mechanism of the pathobiology, and then I can move on to another problem to solve.”
Learn about last year’s Young Alumni Award recipient here.