Many diseases remain less understood and untreatable, but as researchers tap into and combine the potentials of so-called organ-on-a-chip and stem cell technologies, the wait of patients suffering from rare and currently incurable diseases may soon be over.

In a new study published in Nature Medicine on May 11, researchers grew human heart tissue that carries the rare metabolic heart disease Barth syndrome (BTHS), an inherited disease that exclusively affects males and is caused by the mutation of the tafazzin gene (TAZ).

Patients with BTHS have low levels of white blood cells, weak heart muscles and suffer from frequent bacterial infections. To date, the life-threatening condition remains incurable and current treatments are only aimed at reducing the symptoms and complications of the disease, which include serious bacterial infection, heart failure and arrhythmia, the abnormal rhythm of the heart that could potentially cause death.

The researchers engineered the skin cells of two BTHS patients into stem cells that have the patients' TAZ mutation and then grew them on chips that contain human extracellular matrix proteins, which mimics the cellular environment in the human body prompting the cells to join as if they were developing a human heart with BTHS.

By observing how the cells grow and behave, the researchers discovered how the TAZ mutation works and came up with the first tissue-based model for correcting problems associated with the genetic disease.

"The TAZ mutation makes Barth syndrome cells produce an excess amount of reactive oxygen species or ROS -- a normal byproduct of cellular metabolism released by mitochondria -- which had not been recognized as an important part of this disease," said William Pu, from the Harvard Medical School. "We showed that, at least in the laboratory, if you quench the excessive ROS production, then you can restore contractile function."

The research team now attempts to translate the study's finding into a Barth syndrome therapy that can be tested on animals and could potentially benefit human patients. Scientists also use the technology to test drugs that can potentially treat the rare disease.

"Our study provides new insights into the pathogenesis of Barth syndrome, suggests new treatment strategies and advances iPSC-based in vitro modeling of cardiomyopathy," the researchers wrote.

ⓒ 2021 All rights reserved. Do not reproduce without permission.