Figure 1.

Human Fetal Endothelial Cells Show Organ-Specific Heterogeneity Ex Vivo

(A) (A) Representative immunofluorescence images of frozen tissue sections from fetal human kidney, lung, liver, and heart stained with antibodies against CD144 (i) and vWF (ii) with merged (iii) and zoomed (iv) views, and (v) CD31 and vWF. Scale bar: 50 μm (i–iii, v) and 25 μm (iv).

(B–D) Quantification of vWF fluorescence area normalized to the number of CD31-positive cells for all four organs (B), within lungs (C), and kidneys (D). **** p ≤ 0.0001.

(E) Representative immunofluorescence images of frozen tissue sections stained with antibodies against PV1 and Cav1. Scale bar: 50 μm.

(F) Quantification of PV1 fluorescence area normalized to the number of CD31-positive cells for all four organs. ** p ≤ 0.01.

(G) Representative flow cytometry profiles of fresh total cell tissue suspension from fetal human heart, lung, liver, and kidney stained with antibodies against CD45 and CD144. Endothelial population is gated as CD144-positive and CD45-negative cells (left panels). The percentage of endothelial cells is compared among tissues against the total cell number (right panel). Bar plots were made from n = 3 images per donor for two donors (B–D, F) or three donor sets (G). Data are presented as mean ± SEM *p ≤ 0.05. SEM, standard error of the mean.