Nogo-A (Reticulon-4A) (Nogo-A)

Nogo-A is a high molecular weight transmembrane protein predominantly expressed by oligodendrocytes in the central nervous system. It is one of the most potent endogenous inhibitors of neurite outgrowth and axonal regeneration after injury. Nogo-A acts through two main domains—Nogo-A-Δ20 and Nogo-66—which interact with distinct neuronal receptor complexes including sphingosine 1-phosphate receptor 2/tetraspanin-3 for Δ20, and Nogo receptor 1/p75/Troy/Lingo-1 for Nogo-66. These interactions activate intracellular signaling pathways that destabilize the actin cytoskeleton via RhoA activation, leading to growth cone collapse and suppression of neuronal regrowth. Genetic ablation or antibody-mediated blockade against Nogo-A has been shown experimentally to enhance nerve fiber regeneration, improve functional recovery after spinal cord injury, reduce muscle denervation in ALS models, and increase myelination potential during development. As such, it is considered a key therapeutic target for promoting neural repair following CNS injuries or neurodegeneration; however, no approved drugs currently target this molecule directly.

Other names

Reticulon 4-ARtn4aNeurite outgrowth inhibitor AMyelin-associated neurite outgrowth inhibitor

Experimental approaches include antibody-mediated neutralization or genetic ablation to promote axonal regeneration by blocking the inhibitory effect on neurite growth.