PIEZO1 characterization during mouse and human embryonic development. (A) PIEZO1 mRNA levels (normalized to GAPDH) in murine C57BL/6 embryos at E9.5, E10.5, E12.5, E15.5 and P0. Mean + SEM of 3 experiments. (B) Immunoblot showing expression of PIEZO1 protein expression in lung, spleen, liver, and bone marrow from P0 C57BL/6 mouse. Protein (50 μg) was loaded in each lane, with GAPDH as loading control. Representative of 2 independent fresh tissue lysate preparations. (C) Immunoblot showing PIEZO1 protein RBC membranes prepared from blood pooled from 8 adult C57BL/6 mice. Protein (50 or 100 μg) was loaded in each lane, with GAPDH as loading control. One of 3 similar experiments with independent membrane preparations. (D) Immunoblot showing PIEZO1 protein in human RBC membranes prepared from blood pooled from 3 healthy subjects for each lane. Protein (50 μg) was loaded in each lane, with GAPDH as loading control. One of 3 similar experiments with independent membrane preparations. (E) Immunohistochemical expression in human fetal (17 weeks of gestations) and adult tissues with PIEZO1 rabbit polyclonal antibody. The red arrow in the ×400 liver panel indicates a positive erythroblast. The red arrows in the fetal peritoneum panels indicate positive staining in the lymphatic vessels, while in the adult peritoneum panels indicate negative staining in the lymphatic vessels. Antigen is stained brown; nuclei are stained in purple with hematoxylin. Tissues were imaged with a Leica microscope equipped with 20× and 63× objectives. Representative of 3 independent experiments. GAPDH, glyceraldehyde-3-phosphate dehydrogenase.