Astrocytic heterogeneous nuclear ribonucleoprotein U is involved in scar formation after spinal cord injury

Astrocytes play a helpful role in fixing tissue after injuries to the brain and spinal cord. When these injuries happen, astrocytes start to multiply, but we don't know exactly how this multiplication works inside the cells. This study found that a molecule called heterogeneous nuclear ribonucleoprotein U (Hnrnpu) might be key in controlling how astrocytes multiply and form scars. When the researchers stopped Hnrnpu from working in astrocytes, it made it harder for the astrocytes to form scars, and the mice had trouble recovering their movement and regrowing nerve cells after spinal cord injuries. In human astrocytes, blocking HNRNPU reduced the activity of genes that help astrocytes form scars and regrow nerve cells. These results suggest that changing how astrocytes work by targeting Hnrnpu could be a good way to help people recover from brain and spinal cord injuries.

• 1
  Hnrnpu promotes astrocyte reactivity. Inhibiting Hnrnpu suppresses astrocyte migration and alters expression of the genes associated with astrocyte reactivity in  vitro.
• 2
  In the spinal cord injury model, suppression of Hnrnpu decreases astrocyte proliferation, impairs astrocytic scar formation, prevents the aid of neuronal circuits, and motor function recovery.
• 3
  inhibition of astrocytic Hnrnpu expression causes impairment of neural tissue repair and functional recovery after injury, suggesting that endogenous astrocytic Hnrnpu is involved in functional recovery of mice after SCI.