A small molecule called Sephin1 may be able to significantly delay harm to neurons in multiple sclerosis (MS) by protecting oligodendrocytes, limiting the autoimmune response, a mouse study reports.
The study, “Sephin1, which prolongs the integrated stress response, is a promising therapeutic for multiple sclerosis,” was published in the journal Brain.
MS is thought to be caused by immune-mediated inflammation that damages the myelin — an insulating sheath around nerve cells. For this reason, current MS disease-modifying treatments focus on immune-mediated inflammation. Although these treatments moderate disease relapses, their impact on disease progression is unclear.
Previous studies have demonstrated that oligodendrocytes — cells that produce myelin — are critical in protecting against neuron demyelination and axon (nerve fiber) damage. As a result, researchers have been keen to develop alternative therapeutic approaches that protect oligodendrocytes, and ultimately limit disease progression.
A signaling pathway called integrated stress response that acts as a natural defense system to protect cells has been shown to reduce the inflammatory impact on oligodendrocytes. This response is triggered by phosphorylation (a chemical reaction) of a protein called eukaryotic initiation factor 2 alpha (eIF2α), and reduces the total production of proteins, instead promoting the synthesis of protective proteins in the cells.
Conversely, the integrated stress response can be cut off by dephosphorylation of eIF2α. Sephin1 was shown to inhibit the dephosphorylation of eIF2α, prolonging the protective response.
In this study, researchers at the University of Chicago proposed that Sephin1, by producing this response, could protect oligodendrocytes and slow the progress of the disease. The team tested their hypothesis in a mouse model called experimental autoimmune encephalomyelitis (EAE), which is similar to MS in humans.
Results showed that treatment with Sephin1 did inhibit eIF2α dephosphorylation in EAE mice, triggering a protective response against inflammation. More importantly, myelin-producing oligodendrocytes were also protected, and disease onset was significantly delayed.