Transcriptional profiling of murine oligodendrocyte precursor cells across the lifespan
Oligodendrocyte progenitor cells (OPCs) are highly dynamic, abundant glial cells of the central nervous system (CNS) that are responsible for generating myelinating oligodendrocytes during development. OPCs are also mobilized to form new myelin sheaths in the adult CNS in response to environmental and behavioral changes, and play a crucial role in regenerating myelin following demyelination (remyelination). However, the rates of OPC proliferation and differentiation decline dramatically with aging, impairing homeostasis, remyelination, and potentially adaptive myelination during learning. To determine how aging influences OPCs, we generated a novel transgenic mouse line that expresses EGFP under the endogenous promoter/enhancer of Matrilin-4 (Matn4-mEGFP), allowing OPCs to be purified apart from perivascular and mural cells. OPCs isolated from the cerebral cortex of Matn4-mEGFP mice were subjected to single-cell RNA sequencing, providing enhanced resolution of transcriptional changes during key transitions from quiescence to proliferation and differentiation. Comparative analysis of OPCs isolated from mice aged 30 to 720 days, revealed that aging induces distinct inflammatory transcriptomic changes in OPCs in different states, including enhanced activation of HIF-1a and Wnt pathways. Inhibition of these pathways in acutely isolated OPCs from aged mice promoted their differentiation, suggesting that this enhanced signaling may contribute to the decreased regenerative potential of OPCs with aging. This Matn4-mEGFP mouse line and single-cell mRNA datasets of cortical OPCs across ages serve as a valuable reference to help define the molecular changes guiding their behavior in various physiological and pathological contexts. Overall design: Matn4-mEGFP OPCs from 1) 6x P30 cortex, 2) 4x P180 cortex, 3) 5x P360 cortex, 4) 5x P720 cortex to study the effect of aging on the transcriptome of OPCs in the mouse cortex