Gene Mutation Found in High-Altitude Yaks Accelerates Brain Myelin Repair, Reduces MS Symptoms in Mice

Scientists studying how animals survive at extreme altitudes have discovered a genetic mutation in yaks and Tibetan antelopes that dramatically accelerates the repair of the brain's protective myelin sheath — and when the same mutation was administered to mice with multiple sclerosis-like conditions, it reduced disease severity and improved motor function, pointing toward a potential new class of treatments for MS and other demyelinating neurological disorders.

The research, published in the journal Neuron by a team at Songjiang Hospital affiliated with Shanghai Jiao Tong University School of Medicine and led by professor Liang Zhang, began with an evolutionary question: how do high-altitude mammals maintain normal brain function in environments where oxygen levels are 40 percent lower than at sea level? Neurons are extraordinarily sensitive to oxygen deprivation, and the myelin that insulates nerve fibers — allowing electrical signals to travel quickly and efficiently — is particularly vulnerable to hypoxic stress.

The team identified a specific mutation in a gene called Retsat, which encodes an enzyme involved in vitamin A metabolism. In yaks and Tibetan antelopes — both of which have evolved over millennia to thrive at altitudes above 14,000 feet — the Retsat mutation increases production of a compound called ATDR, a metabolite of vitamin A. ATDR was found to directly stimulate oligodendrocytes, the specialized brain cells responsible for producing and maintaining myelin, enhancing both their growth and their ability to regenerate myelin that has been damaged by injury or disease.

"Evolution is a great gift from nature, providing a rich diversity of genes that help organisms adapt to different environments," Zhang said. "What we found is that this high-altitude adaptation also happens to solve a problem that has no effective solution in human medicine."

In laboratory mice carrying the Retsat mutation, the team found improved learning and memory performance, enhanced social behavior, and faster myelin recovery following oxygen deprivation compared to normal mice. Crucially, when the team induced MS-like demyelinating disease in a separate group of mice and then administered ATDR directly — bypassing the need for the genetic mutation — disease severity was measurably reduced and motor function improved relative to untreated controls.

Multiple sclerosis affects approximately 2.9 million people worldwide and is caused by the immune system attacking and stripping away myelin from nerve fibers throughout the brain and spinal cord. Current MS treatments focus primarily on suppressing the immune attack, but they do little to help the brain repair myelin that has already been lost. Remyelination — the regeneration of new myelin by oligodendrocytes — does occur naturally but is often incomplete, particularly as the disease progresses and oligodendrocyte reserves are depleted.

The ATDR pathway discovered in high-altitude animals represents a distinct approach: rather than blocking immune damage, it activates the brain's own repair machinery. The compound's mechanism of action — stimulating oligodendrocyte proliferation and differentiation through a well-characterized vitamin A metabolite pathway — is considered relatively tractable for pharmaceutical development, as vitamin A derivatives have a long history of clinical use and the ATDR molecule's properties are well understood.

The research team has begun characterizing ATDR's safety profile and optimal dosing in further animal models and is working with industry partners to assess the feasibility of a clinical development program. Scientists not involved in the study called the findings compelling but cautioned that translating animal results in demyelinating disease to human MS has historically proven difficult, and that rigorous clinical trials would be needed before the approach could be used in patients.