Fig. 2

Both human 1 and mouse platelets express ACE2 and TMPRSS2. A, RT2 PCR detection of ACE2 (A1) and monocyte-specific CD14 (A2) in healthy human platelets. B, Western blot detection of ACE2 and monocyte-specific CD14 (B2) in healthy human platelets. For A and B, the human colon cell line Caco-2 and the human lung cell line Calu-3 were used as positive controls of ACE2, and the human Hela cell line was used as a negative control of ACE2. The peripheral blood mononuclear cells (PBMCs) from healthy human were used as a positive control of CD14. C, RT-PCR detection of ACE2 (C1) in lungs, hearts, and platelets from wild-type mice. D, Western blot detection of ACE2 in lungs, hearts, and platelets from wild-type mice. For C and D, PBMCs from mice were used as a positive control of CD14. E, RT-PCR detection of TMPRSS2 in platelets from healthy human and wild-type mice. F, Western blot detection of TMPRSS2 in platelets from healthy human and wild-type mice. For E and F, the colon cell line Caco-2 and the human lung cell line Calu-3 from human and the lungs from mice were used as positive controls of TMPRSS2, and the human prostate cell line PC-3 was used as a negative control of TMPRSS2. For A to F, platelet-rich plasma prepared as previously described was filtered through a Sepharose 2B column equilibrated in Tyrode’s solution to isolate platelets. Platelets1 in A, B, E left panel and F left panel were platelets from 1 healthy blood sample and platelets2 in A, B, E left panel and F left panel were platelets mixture from 20 healthy donors. Platelets1 in C, D, E right panel and F right panel were platelets from 1 wild-type mouse and platelets2 in C, D, E right panel and F right panel were platelets mixture from 5 wild-type mice. PBMCs were isolated by centrifugation on a Ficoll-Paque from two different blood samples of healthy donors (PBMCs1 and PBMCs2 in A and B) and from two different blood samples of wild-type mice (PBMCs1 and PBMCs2 in C and D). The two different lung (lung1 and lung2 in C, D, E and F) and heart (heart1 and heart2 in C and D) tissues were dissected from different wild-type mice. G, Western blot detection of ACE2 and TMPRSS2 in megakaryocyte cell line (Meg-01). H, Detecting ACE2 and TMPRSS2 expression on healthy human and wild-type mice platelets by flow cytometry. I, Imaging of ACE2 (I1) and TMPRSS2 (I2) expression in healthy human platelets using confocal microscopy. ACE2, the angiotensin converting enzyme 2; TMPRSS2, transmembrane protease serine 2; and RT-PCR, reverse transcription polymerase chain reaction. Images were representative of three independent RT-PCR, Western blot or flow cytometry experiments