Glial scar formation

Glial scar formation is a reactive cellular and molecular process following injury to the central nervous system (CNS), characterized primarily by the proliferation and morphological transformation of astrocytes and other glial cells, including microglia and oligodendrocyte precursor cells[1][3][4]. Astrocytes in the vicinity of injury switch to a reactive state, upregulating proteins such as glial fibrillary acidic protein (GFAP), and secrete extracellular matrix molecules including chondroitin sulfate proteoglycans, laminin, fibronectin, and tenascin, forming a physical and molecular barrier around the lesion. This process, called astrogliosis, produces a compact, dense border (the glial scar) that both limits the spread of damage and inflammation and inhibits axonal regeneration[1][3]. Molecular mediators of glial scar formation include transforming growth factor-beta (TGF-β1, TGF-β2), interleukin-1, cytokines such as interferon-gamma (IFNγ), and fibroblast growth factor 2 (FGF2), as well as molecules like RGMa which cooperate with the TGF-β pathway[1][5][6][7]. Functionally, while the glial scar provides acute neuroprotection and restores homeostasis, it forms a long-lasting barrier to axonal regrowth and functional recovery after CNS injury[2][3][8]. The glial scar is not a single molecular entity or defined receptor but a complex, multicellular, and molecularly heterogeneous structure—a phenomenon or pathological process, not a traditional drug target[3][9]. For this reason, "Glial scar formation" is not considered a canonical therapeutic target but a process/pathology composed of multiple potential molecular targets (e.g., specific astrocyte signaling pathways, extracellular matrix molecules) that could be manipulated to modulate scarring and improve recovery.

Other names

GliosisReactive gliosisGlial scarGlial scarring