A Pericyte Origin of Spinal Cord Scar Tissue

TLDR

Central nervous system injury leads to limited regeneration, with lesions sealed by a complex scar rich in astrocytes. A specific pericyte subtype generates scar‑forming stromal cells that outnumber astrocytes, and inhibiting this lineage prevents tissue sealing, revealing the cellular source of spinal cord fibrosis.

Abstract

There is limited regeneration of lost tissue after central nervous system injury, and the lesion is sealed with a scar. The role of the scar, which often is referred to as the glial scar because of its abundance of astrocytes, is complex and has been discussed for more than a century. Here we show that a specific pericyte subtype gives rise to scar-forming stromal cells, which outnumber astrocytes, in the injured spinal cord. Blocking the generation of progeny by this pericyte subtype results in failure to seal the injured tissue. The formation of connective tissue is common to many injuries and pathologies, and here we demonstrate a cellular origin of fibrosis.