Fig 1: A schematic overview of ANGPT2 signaling in health and in hypercoagulation with high levels of ANGPT2 inhibiting TM-mediated anticoagulation. Thrombin/TM normally catalyzes protein C (PC) to activated protein C (APC), which inhibits Factor VIIIa and Factor Va. Increased levels of ANGPT2 in mice reduces tail bleeding time and plasma APC, while increasing TAT. In critically ill COVID-19 patients, ANGPT2 is increased and correlates to reduced kidney function, hypercoagulation, and mortality.
Fig 2: (a) TEG data from one of the donors showing sTM-dependent (blue) increase in reaction time (R) and decreased maximal amplitude (MA), which is inhibited by ANGPT2 (red); (b,c) TEG analysis of individual donor blood with 20 nM sTM) and 40 nM ANGPT2. Statistical comparison with repeated measures ANOVA with Bonferroni post hoc test. Additional TEG results can be found in Table 1.
Fig 3: TM-dependent activation of protein C (APC) can be inhibited with ANGPT2 or ANGPT1. Human healthy donor plasma was supplemented with sTM (20 nM) and incubated with 40 nM ANGPT2, IgG or ANGPT1. Data are presented as mean ± 95% CI. Statistical comparison from one-way ANOVA with Bonferroni post hoc test.
Fig 4: (a) Plasma ANGPT2 concentrations for healthy controls (HC), recovered (Rec), and deceased (Dec) patients at day 1–4 and day 10–14 after admission; (b) Kaplan–Meier survival plot with Log-rank test show that ANGPT2 levels can predict survival; (c) Plasma ANGPT1 was minimally affected; (d) Clinical data and measured parameters were analyzed by Pearson correlation test (Spearman for SAPS-3 and SOFA score) and presented in a heatmap for correlation (blue) or inverse correlation (red), * p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001; (e) ANGPT2 is higher in patients with acute kidney injury (AKI) compared to non-AKI patients; (f) ANGPT2 is higher in patients with TEG MA > 69 mm. Data are presented as mean ± 95% CI. Statistical comparison from one-way ANOVA with Bonferroni post hoc test (a,b) or Student’s t-test (e,f). AKI, acute kidney injury; TEG, thromboelastography; MA, maximal amplitude.
Fig 5: (a) Plasma concentration of ANGPT2 in Angpt2iECKO mice and wildtype (WT) littermate controls; (b) Tail bleeding time in Angpt2iECKO mice and wildtype (WT) littermate controls. (c) Tail bleeding time in Tie2iECKO mice and littermate controls (WT). Data presented as mean ± 95% CI. Statistical comparison with Student’s t-test.
Supplier Page from Abcam for Recombinant Human Angiopoietin 2/ANG2 protein (His tag)