In situ expression of hematopoietic niche markers by human perivascular cells. (A-D) Immunohistochemistry performed on paraffin-embedded sections of 17-week-old human FBM. Pericytes surrounding microvessels express (A) CD146, (B) nestin, (C) CXCL12, and (D) leptin receptor (Lep-R) (original magnification, ×63). (E-S) Immunohistochemistry performed on human adipose tissue cryosections. (E-G) VWF-positive endothelial cells (green) are surrounded by perivascular cells expressing (E) nestin, (F) CXCL12, and (G) Lep-R. (H-S) Triple-staining immunohistochemistry performed on human adipose tissue cryosections shows coexpression of CD146 with (K-M) nestin, (N-P) CXCL12, and (Q-S) LepR. (H-J) Single staining with anti-VWF antibody followed by incubation with conjugated IgG controls revealed the lack of autofluorescence (original magnification, ×40). IgG, immunoglobulin G.