Distant brain cells guide spinal cord healing
Scientists have discovered that star-shaped brain cells far from a spinal cord injury site act as crucial repair coordinators. These cells, called astrocytes, release a protein named CCN1 that guides microglia, the brain's cleanup crew, to properly clear away damaged myelin, the protective coating around nerve fibers. When astrocytes cannot produce CCN1, microglia become overactive and dysfunctional, hoarding debris instead of disposing of it. This leads to failed nerve repair and poorer recovery in injured mice. The study reveals that CCN1 helps microglia store fats properly, which is essential for their cleanup function. Intriguingly, these CCN1-producing astrocytes appear not only after spinal cord injury but also in multiple sclerosis and similar diseases in both mice and humans. The discovery opens new avenues for treating spinal cord injuries and demyelinating diseases by targeting this cellular communication pathway.
After spinal cord injury, lesion-remote astrocytes acquire heterogeneous, spatially restricted reactivity states that shape neuroinflam