β actin

Grafts and their adjacent abdominal aorta were separated at the endpoint of the rats observation. Protein extract and western blot analysis were performed as described previously [26 (link)]. Blots were incubated with primary antibodies for VEGFR2 (1:600, Servicebio) and β-actin (1:1000, Servicebio).
Grafts peeling off the adventitia were also carried out in western blot analysis. Blots were incubated with primary antibodies for endothelial nitric oxide synthase (eNOS) (1:1000, Abcam) and β-actin (1:1000, Servicebio).
The grayscale of indicated protein was quantified by ImageJ software.

The total protein was extracted from the jejunal and ileal mucosa using radio immunoprecipitation assay (RIPA) lysis buffer and quantified using a bicinchoninic acid (BCA) protein assay kit (Beyotime Institute of Biotechnology, Shanghai, China). Proteins were separated using 8–10% sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) (Yeasen Biotechnology Co., Ltd., Shanghai, China) and transfected to PVDF membranes. Membranes were blocked with a rapid blocking solution (Beyotime Institute of Biotechnology, Shanghai, China) for 30 min and incubated overnight with primary antibodies, including spdef (1:1000; Hunan Aifang Biotechnology Co., Ltd., Changsha, China), GRP78 (1:1000; Hunan Aifang Biotechnology Co., Ltd., Changsha, China), bcl-2 (1:1000; Hunan Aifang Biotechnology Co., Ltd., Changsha, China), and β-actin (1:1000; Wuhan Service Bio Technology; Wuhan, China) at 4 °C, followed by incubation with secondary antibody horseradish peroxidase-conjugated goat anti-rabbit or mouse IgG (1:5000; ZSGB Biological Technology, Beijing, China) for 2 h at room temperature. All target protein measurements were quantified by measuring the intensity of bands using Alpha Imager 2200 Software (Alpha Innotech Corporation, San Leandro, CA, USA) and normalized to β-actin.

FEMPs were acquired in our lab according to the previous method. DSS (Mw, 50000 Da) was purchased from Sigma-Aldrich Trading Co., Ltd. (Shanghai). Biodewax and clear solution, 4′,6-diamidino-2-phenylindole (DAPI), and ethylenediamine tetraacetic acid (EDTA) (pH 8.0) antigen retrieval solution were bought from Wuhan Servicebio Technology Co., Ltd. Ethanol was purchased from Sinopharm Chemical Reagent Co., Ltd, and BCA protein quantitative detection kit, β-actin, and TBS buffer solution were bought from Wuhan Servicebio Technology Co., Ltd.