Glenzocimab does not impact glycoprotein VI-dependent inflammatory haemostasis

Abstract

Not available.

Figure 1.

Contribution of glycoprotein VI to inflammation-associated hemostasis. The contribution of glycoprotein VI (GPVI) to inflammation-associated hemostasis was determined in three different models of acute inflammation. (A) Representative images of brain sections taken 24 hours after GPVI+/+, GPVI-/-, GPVI-/-, and platelet-depleted mice were subjected to 90 minutes transient middle cerebral artery occlusion (tMCAO). Note that tMCA0 caused bleeding only in platelet-depleted mice. The images are representative of n=6 mice per group. (B) Representative images of the bronchoalveolar lavage fluid from Gpvi+/+, Gpvi- /-, and platelet-depleted mice collected 24 hours after lipopolysaccharide inhalation. The images are representative of n=8 mice per group. (C and D) Effect of partial or complete GPVI deficiency on inflammatory bleeding during the cutaneous reverse passive Arthus reaction (rpA). (C) Representative images of the skin of GPVI+/+, GPVI-/-, GPVI-, and platelet-depleted mice after 4 hours of rpA. The images are representative of n=7-10 mice per group. Bar =500 mm. (D) Skin hemoglobin content after 4 hours of rpA. # indicates a significant difference (P<0.05) from the rpA GPVI+/+ group, n=14-20 skin biopsies per group. Inset: Representative histogram of flow cytometry analysis of GPVI surface levels in GPVI+/+, GPVI+/-, and GPVI-/- mice, as assessed using the JAQ1 antibody to representative mouse GPVI.

Figure 2.

Impact of ACT017 on glycoprotein VI-dependent hemostasis. (A and B) Citrated whole blood from hGPVI mice was labeled with the fluorochrome DiOC6, incubated or not with ACT017 (80 mg/mL) for 10 minutes, and perfused at a wall shear rate of 1,500 s–1 or 100 s–1 for 3 minutes over a collagen-coated surface. Bar=50 mm. (A) Representative images of platelet coverage at the end of the perfusion. (B) Mean surface areas covered by platelets calculated from 20 different fields taken with a 20x objective along channels from four different runs (five fields per run). (C) Representative images of the skin of hGPVI mice treated or not with ACT017 (64 mg/kg) after 4 hours of reverse passive Arthus reaction (rpA). The images are representative of n=4-9 mice per group. Bar=500 mm. (D) Skin hemoglobin content after 4 hours of rpA. # indicates a significant difference (P<0.05) from the rpA hGPVI group, n=6-18 skin biopsies per group. (E and F) Skin myeloperoxidase (E) and platelet factor 4 (PF4) (F) content after 2 hours of rpA, as assessed by enzyme-linked immunosorbent assay; n=12 skin biopsies per group.