TRAP Induces Obesity Figure 5. Macrophages are the primary source of monomeric TRAP in mouse and human adipose tissue. (A) mRNA expression of the monocyte/macrophage marker F4/80 and c-fms in adipose tissue of TRAP+ vs. WT mice. (B) Immunohistochemistry of mouse macrophage marker F4/ 80 in adipose tissue from TRAP+ compared to WT mice (C) mRNA for the myeloid lineage specific TRAP transcript 1C in adipose tissue of WT and TRAP+ mice. (D) Expression of monomeric TRAP in adipose tissue (T) and isolated adipocytes (Ad) from five subjects (Pat 1–5). (E) TRAP mRNA expression in human adipose tissue and in isolated adipocytes. (F) Co-localization between monomeric or total TRAP and the macrophage marker CD68 in subcutaneous human adipose tissue from a representative subject. (G) Monomeric TRAP is secreted from the mouse macrophage cell line RAW 264.7 (lane 1), whereas proteolytically processed TRAP is not detectable (lane 2). doi:10.1371/journal.pone.0001713.g005 PLoS ONE | www.plosone.org 7 March 2008 | Volume 3 | Issue 3 | e1713