Journal News

Sibling study reveals mechanism for genetic disease

Ken Hallenbeck
Feb. 13, 2024

Genetic diseases pass from parents to children — often in surprising ways. The unpredictability of these transfers means that sometimes a disease skips whole generations, while other times it may affect only one sibling. Pairs of affected and unaffected siblings provide a unique opportunity for scientists to study the molecular mechanisms of genetic disease.

Unraveling the connection between the genetic mutation a person carries and the symptoms they have has been a decades-long focus of Yi-Wen Chen’s laboratory, part of the Center for Genetic Medicine Research at Children’s National Hospital in Washington, D.C. Chen’s expertise is in genetic muscle disorders, which occur in 59 out of every 100,000 adults in the United States.

Muscle weakness can sometimes start early – even in the womb. Other times, as is the case with the second-most common muscle disorder, adult-onset facioscapulohumeral muscular dystrophy, or FSHD, symptoms begin much later, in adolescence or early adulthood. Why is this, and does it hint at a way to design treatment?

To answer these questions, Chen’s laboratory teamed up with proteomics expert Jatin Burniston of the Research Institute for Sport and Exercise Sciences at Liverpool John Moores University. They studied affected and unaffected sibling pairs using proteomics experiments designed to reveal the underlying mechanisms of FSHD.

The researchers took cell cultures from each sibling and incubated them with deuterium, or “heavy water.” Then, they tracked the lifespan of each protein in the cell with mass spectrometry. The results, described in a recent article in Molecular & Cellular Proteomics, implicate slower turnover of mitochondrial proteins, but more abundant mitochondrial proteins in the sibling with FSHD. Slower turnover means old proteins — which should be recycled — pile up in the mitochondria, triggering stress responses and interrupting normal cell function. The finding is a clever combination of atomic-level detail and good biological controls.

Yusuke Nishimura, a postdoctoral research associate in Burniston’s lab was a co-first author on the paper.

“Mitochondrial dysfunction and mitochondrial stress in FSDH had been identified in previous studies,” Nishimura said. However, that information alone wasn’t enough to begin designing a treatment. Because FSHD varies widely between individuals, “studying (the) underlying biological mechanisms is challenging,” he said.

Differences in protein turnover observed when comparing FSDH patients with healthy individuals may not be caused by the disease, but simply be normal variances between unrelated people. That’s where the sibling pair comes in — by simultaneously analyzing a sibling with FSHD and a sibling without the disease, Nishamura and collaborators were able to unravel the FSHD mystery.

FSHD has no treatment or cure. “Our new data on mitochondrial protein dynamics in FSHD is particularly exciting because highlighting dysfunctions in protein turnover offers a potential new therapeutic route,” Nishimura said.

Next, researchers must find a way to increase protein recycling in the mitochondria and test if the improved turnover relieves FSHD symptoms. To do so, they need to develop better mouse models of FSHD. If the evidence continues to mount, therapeutic strategies such as targeted protein degradation might be used to restore order to the mitochondria in FSHD patients.

Enjoy reading ASBMB Today?

Become a member to receive the print edition four times a year and the digital edition monthly.

Learn more
Ken Hallenbeck

Ken Hallenbeck earned a Ph.D. in pharmaceutical sciences from the University of California, San Francisco, and now is an early drug-discovery researcher. He serves on the board of directors of ReImagine Science and is the life sciences lead at TerraPrime.

Get the latest from ASBMB Today

Enter your email address, and we’ll send you a weekly email with recent articles, interviews and more.

Latest in Science

Science highlights or most popular articles

Finding a symphony among complex molecules
Profile

Finding a symphony among complex molecules

April 23, 2025

MOSAIC scholar Stanna Dorn uses total synthesis to recreate rare bacterial natural products with potential therapeutic applications.

E-cigarettes drive irreversible lung damage via free radicals
Journal News

E-cigarettes drive irreversible lung damage via free radicals

April 17, 2025

E-cigarettes are often thought to be safer because they lack many of the carcinogens found in tobacco cigarettes. However, scientists recently found that exposure to e-cigarette vapor can cause severe, irreversible lung damage.

Using DNA barcodes to capture local biodiversity
ASBMB Annual Meeting

Using DNA barcodes to capture local biodiversity

April 15, 2025

Undergraduate at the University of California, Santa Barbara, leads citizen science initiative to engage the public in DNA barcoding to catalog local biodiversity, fostering community involvement in science.

Targeting Toxoplasma parasites and their protein accomplices
Journal News

Targeting Toxoplasma parasites and their protein accomplices

April 11, 2025

Researchers identify that a Toxoplasma gondii enzyme drives parasite's survival. Read more about this recent study from the Journal of Lipid Research.

Scavenger protein receptor aids the transport of lipoproteins
Journal News

Scavenger protein receptor aids the transport of lipoproteins

April 11, 2025

Scientists elucidated how two major splice variants of scavenger receptors affect cellular localization in endothelial cells. Read more about this recent study from the Journal of Lipid Research.

Fat cells are a culprit in osteoporosis
Journal News

Fat cells are a culprit in osteoporosis

April 11, 2025

Scientists reveal that lipid transfer from bone marrow adipocytes to osteoblasts impairs bone formation by downregulating osteogenic proteins and inducing ferroptosis. Read more about this recent study from the Journal of Lipid Research.