Primary antibody against cd68

Collected rat lung tissues and RV tissues were immediately fixed in 4% polyformaldehyde (pH 7.4) for 24 h, embedded in paraffin, and then sliced into 4 μm sections. Then lung sections were stained with hematoxylin and eosin (H&E), toluidine blue (TB), picrosirius red (PSR) staining, Masson trichrome staining (MTS), and primary antibody against CD68 (Abcam, MA, USA) according to the protocols described previously [17 (link)]. Pulmonary arterial wall thickness (PAWT) was determined according to the ratio of (external diameter − internal diameter) to external diameter based on H&E staining. The right ventricular hypertrophy was determined by the cross section area (CSA) of cardiomyocytes using H&E staining. Graphs were observed under a Leica 2500 microscope (Leica Microsystems, Wetzlar, Germany).

For purpose of TAMs isolation, CRC tissues from patients underwent surgery were sliced up. The tissues were incubated with DMEM contained with ACCUMAX (Sigma‑Aldrich, Darmstadt, Germany) in a 5% CO₂-humidified incubator at 37 °C for 2 h, subsequently percolated with 40 μm strainer (Thermo Fisher Scientific, Inc., Waltham, MA, USA). The cells were stained by primary antibody against CD68 (Abcam, Cambridge, MA, USA) to isolate and analysis TAMs. The isolated TAMs were seeded into a six-well plate for follow-up research. TAMs were cultured not exceeding 7 days.