Identifying Matrix‐ and Transporter‐Type Pericytes in Human Brain

Pericytes are vascular mural cells that wrap around capillaries and are crucial for the formation and maintenance of the blood‐brain barrier (BBB). A recent RNAseq study discovered that the human brain has two novel and distinct pericyte subtypes (Yang et al., 2022). The first, termed transporter (T)‐type, are enriched with transporter genes. The second are matrix (M)‐type pericytes which have increased expression of extracellular matrix (ECM) genes. Notably, the authors found that a decrease in M‐type pericytes and not T‐type pericytes contributes to the formation of Alzheimer’s Disease (AD). The loss of M‐type pericytes is speculated to lead to perturbations of vascular ECM. Here, we aimed to determine which protein markers work best for the identification of M‐ and T‐type pericytes and their localization in human hippocampal and cortical post‐mortem brain tissues.