OHSU researchers develop possible ‘game-changer’ for MS

A scientific breakthrough provides new hope for millions of people living with multiple sclerosis. Researchers at OHSU have developed a compound that stimulates repair of the protective sheath that covers nerve cells in the brain and spinal cord.

The discovery, involving mice genetically engineered to mimic multiple sclerosis, published Thursday in the journal JCI Insight.

MS is a chronic condition that affects an estimated 2.3 million people worldwide. In MS, the sheath covering nerve fibers in the brain and spinal cord becomes damaged, slowing or blocking electrical signals from reaching the eyes, muscles and other parts of the body. This sheath is called myelin. Although myelin can regrow through exposure to thyroid hormones, researchers have not pursued thyroid hormone therapies due to unacceptable side effects.

Although several treatments and medications alleviate the symptoms of MS, there is no cure.

“There are no drugs available today that will re-myelinate the de-myelinated axons and nerve fibers, and ours does that,” said senior author Tom Scanlan, Ph.D., professor of physiology and pharmacology in the OHSU School of Medicine.

Co-author Dennis Bourdette, M.D., chair of neurology in the OHSU School of Medicine and director of the OHSU Multiple Sclerosis Center, said he expects it will be a few years before the compound advances to the stage of a clinical trial involving people. Yet the discovery provides fresh hope for patients in Oregon and beyond.

“It could have a significant impact on patients debilitated by MS,” Bourdette said.

The discovery reported Thursday, if ultimately proven in clinical trials involving people, appears to accomplish two important goals:

Myelin repair with minimal side effects: The study demonstrated that the compound – known as sobetirome – promotes remylenation without the severe side effects of thyroid hormone therapy. Thyroid hormone therapy has not been tried in people because chronic elevated exposure known as hyperthyroidism harms the heart, bone, and skeletal muscle. Efficient delivery: Researchers developed a new derivative of sobetirome (Sob-AM2) that penetrates the blood brain barrier, enabling a tenfold increase in infiltration to the central nervous system.

“We’re taking advantage of the endogenous ability of thyroid hormone to repair myelin without the side effects,” said lead author Meredith Hartley, Ph.D., an OHSU postdoctoral researcher in physiology and pharmacology.

Co-authors credited the breakthrough to a collaboration that involved scientists and physicians with expertise ranging across neurology, genetics, advanced imaging, physiology and pharmacology.

https://news.ohsu.edu/2019/04/18/study-shows-promise-in-repairing-damaged-myelinFor more information: