Journal: Scientific Reports
Article Title: Robo4 is constitutively shed by ADAMs from endothelial cells and the shed Robo4 functions to inhibit Slit3-induced angiogenesis
doi: 10.1038/s41598-022-08227-8
Figure Lengend Snippet: ADAM10 and ADAM17 are Robo4 sheddases. ( A ). Single-cell RNAseq transcriptome analysis of ADAM expression in dEC in adult C57BL/J mice . ADAM expression was normalized to GAPDH in the same cell, and the mean value in each mouse was calculated. The top 10 expressing ADAMs in dEC are plotted. The full list of analyzed ADAM s is included in the Methods. ( B ) Quantitative RT-PCR analysis determined the mRNA expressions of ADAM10 , ADAM17 , ADAMTS-4 , and ADAMTS-5 in a mouse dEC line, and the data were normalized to ADAM10 expression. ( C – F ) Pharmacological inhibition of ADAM10, ADAM17, or both blocked Robo4 shedding in dEC ( C ), mouse lung endothelial cells ( E ), and primary HUVECs ( F ) and led to corresponding increased cell surface Robo4 ( D ). The endothelial cells were treated with GI, TAPI-2, or GW at 6 μM or vehicle (DMSO) for 6 h, and sRobo4 in conditioned medium was assessed and normalized to full-length Robo4 in the cell lysate. The data was further normalized to the DMSO group for comparison. The dEC cell surface Robo4 was assessed by flow cytometry after staining with an anti-Robo4 ectodomain antibody. Anti-Robo4 IgG and naïve IgG staining are drawn in heavy-bright and thin-faint lines, respectively, with corresponding colors. ( G ) Knockdown (KD) of ADAM10 and ADAM17 . dECs were transiently transfected with scramble shRNA or shRNA against ADAM10 or ADAM17 , and ADAM10 and ADAM17 expression in the shRNA-treated cells were assessed by Western blot with corresponding specific antibodies. Black bars separate lanes that are nonadjacent in the same blot. ( H ) Knockdown of ADAM10 or ADAM17 each inhibited Robo4 shedding. sRobo4 in 6-h conditioned media was assessed by Western blot. The data represent 3 independent experiments and are presented as mean ± SD. The student’s t-test was performed for two-group comparisons. *p < 0.05; **p < 0.01.
Article Snippet: Anti-N-terminal mouse Robo4 antibody (Abcam, ab10547), anti-N-terminal human Robo4 antibody (R&D Systems, MAB2454), anti-FLAG antibody (Thermo Fisher Scientific, 14-6681-82), anti-HA antibody (Chromotek, #7c9-100), anti-intracellular Robo4 domain antibody (Santa Cruz Biotechnology, sc46497), anti-ADAM10-pro antibody (Abcam, ab39178), anti-ADAM10 antibody (Bioss, bs-3574R; LSbio, C497146-200; Novus, #NBP1-76973), anti-ADAM17 antibody (Bioss, 4236R; Novus #NBP2-61719), anti-Synecan-1 antibody (Santa Cruz Biotechnology, sc-5632), anti-actin antibody (Sigma Aldrich, A2228), anti-GAPDH antibody (R&D Systems, AF5718), polyclonal anti-Unc5B antibody (R&D Systems, AF1006), anti-N-terminal CDH5 (Thermo Fisher Scientific, 14-1441-82), anti-CD31 (BD, #550274), HRP-conjugated anti-His antibody (Alpha Diagnostic International, HISP12-HRP), HRP-conjugated goat anti-rabbit IgG antibody (Santa Cruz Biotechnology, sc-2030), HRP-conjugated donkey anti-goat IgG antibody (Santa Cruz Biotechnology, sc-2020), and HRP-conjugated goat anti-mouse IgG antibody (Invitrogen, 62-6520).
Techniques: Expressing, Quantitative RT-PCR, Inhibition, Flow Cytometry, Staining, Transfection, shRNA, Western Blot