Reactive astrogliosis in the era of single-cell transcriptomics

Astrocytes, essential for CNS homeostasis, react to injury or disease via reactive astrogliosis, changing in number, morphology, and function. Single-cell transcriptomics reveals the diversity of these reactive astrocytes, indicating multifaceted roles in various neuropathologies with temporal and spatial resolution. Transcriptomic signatures of reactive astrocytes overlap across neurological diseases, suggesting shared and unique gene expression patterns. This review provides an overview of reactive astrocyte populations defined by single-cell transcriptomics in multiple neuropathologies. The aim is to facilitate the search for relevant reference points and improve the interpretability of new datasets containing cells with signatures of reactive astrocytes.

• 1
  Single-cell transcriptomics has revealed remarkable heterogeneity of reactive astrocytes, indicating their multifaceted functions in a whole spectrum of neuropathologies, with important temporal and spatial resolution, both in the brain and in the spinal cord.
• 2
  Transcriptomic signatures of reactive astrocytes partially overlap between neurological diseases, suggesting shared and unique gene expression patterns in response to individual neuropathologies.
• 3
  There is a shared “reactive signature” in multiple pathologies, suggesting the existence of a “pan-reactive” expression program, which is partly conserved across species.