Brain macrophages: on the role of pericytes and perivascular cells

Invasion of Hematopoietic Cells into the Brain of Amyloid Precursor Protein Transgenic Mice

“…The observation that the population of perivascular macrophages remained unchanged was unexpected. It is thought that these cells participate in the control and regulation of homeostasis of the interstitial space (Thomas, 1999), which is part of the perivascular clearance pathway of A␤ (Weller et al, 1998). In atherosclerosis and stenosis, the number of new endothelial cells increases and helps to repair and restore endothelial function (Werner et al, 2002).…”

Transcription Profiling of Platelet-Derived Growth Factor-B-Deficient Mouse Embryos Identifies RGS5 as a Novel Marker for Pericytes and Vascular Smooth Muscle Cells

“…10 Pericytes express markers in common with VSMCs, such as ␣-smooth muscle actin (␣-SMA), desmin, and PDGFR␤, which together with the ultrastructural appearance of pericytes suggest that they belong to the VSMC lineage. However, the structural and biochemical diversity of pericytes 2 and the suggested existence of other perivascular pericyte-like mesenchymal cells 11 and of perivascular cells with macrophage-like properties 12 make pericytes hard to define. Pericytes have also been proposed to have the capacity to trans-differentiate into fibroblast-like cells, 13 osteoblasts, chondrocytes, and adipocytes, 11 adding to the confusion regarding the origin, identity, and potency of these cells.…”

Production of Polyclonal Antibodies against Perivascular Macrophages (Mato's FGP Cells) Isolated from Rat Brain Microvessels

“…Perivascular cells [6,10], perivascular microglia [8], and FGP-cells (Fluorescent Granular Perithelium) [12] with macrophage functions in brain are defined in a broad collective sense as pericytes [2,4,19,21,25].…”

“…They are located on the outside of endothels and pericytes or smooth muscle cells [10,12,20], and are different from traditional pericytes [20,26]. They react positively to ED2-antibody, which recognizes a macrophage sub-type in rats [5,6,10,14,25]. Acid phosphatase activity can be observed in the granules and endoplasmic reticulum within perivascular macrophage cytoplasm [12].…”