UCSF Study Identifies DNA Breakdown in Gray Matter Neurons as Critical Driver of Multiple Sclerosis Progression

UCSF researchers identify DNA breakdown in CUX2 neurons as the cause of gray matter loss in MS, opening a new front for neuroprotective therapies.

By: AXL Intelligence

Published: Apr 2, 2026, 4:40 AM EDT

Source: Information for this report was sourced from University of California - San Francisco.

Shifting the Focus from Myelin to Neuronal Integrity

For several decades, the scientific understanding of multiple sclerosis (MS) has been centered almost exclusively on the degradation of myelin, the protective insulation surrounding the brain’s electrical wiring. While the loss of this white matter is a hallmark of the disease, researchers have increasingly noted a parallel and equally devastating phenomenon: the quiet death of neurons in the cerebral cortex. A new collaborative study led by the University of California, San Francisco (UCSF) has now pinpointed the cause of this cellular attrition. The findings suggest that as inflammation saturates the brain, it triggers a catastrophic breakdown in the DNA of gray matter neurons, fundamentally changing the strategic approach required to treat progressive forms of the disease.

The Vulnerability of CUX2 Neurons in Gray Matter

The investigation specifically highlighted a subset of neurons characterized by the expression of the CUX2 gene, which are primarily located in the outer layers of the brain’s gray matter. These neurons are essential for higher cognitive functions but appear to be uniquely susceptible to the stressors of both early development and chronic disease. By examining developing mouse brains, the research team discovered that these cells naturally exist under significant pressure as they multiply and wire the frontal parts of the brain. This inherent fragility makes them the "canary in the coal mine" for MS, as they are often the first cells to succumb when the brain's internal environment becomes hostile due to long-term inflammation.

The Role of ATF4 in Genetic Repair and Survival

Central to the survival of these vulnerable neurons is a stress-response gene known as ATF4, which serves as a critical coordinator for DNA repair. During the rapid growth phases of early life, CUX2 neurons rely on ATF4 to keep their chromosomes intact amidst the mechanical and chemical stresses of brain formation. The researchers demonstrated that when this gene is removed or suppressed, the resulting DNA damage is so severe that it prevents the proper formation of the frontal cortex. In the context of multiple sclerosis, the study suggests that the inflammatory environment of the diseased brain eventually exhausts this ATF4-dependent repair mechanism, leaving the neurons unable to fix the genetic fractures ca...