Abstract Number: OC 22.5
Meeting: ISTH 2022 Congress
Theme: Platelet Disorders, von Willebrand Disease and Thrombotic Microangiopathies » Non-coding RNAs
Background: High von Willebrand factor (VWF) plasma levels are associated with (arterial) thrombosis. Antiplatelet therapy increases bleeding risk and often fails to prevent arterial thrombosis. Lowering of VWF through allele-selective silencing of VWF with small interfering RNAs (siRNAs) would be a personalized approach which averts complete VWF knockdown and thus minimizes bleeding risk.
Aims: To investigate the feasibility of strain-selective siRNA-mediated VWF inhibition in vivo in mice.
Methods: 15 siRNAs targeting murine Vwf were studied on activity and allele-selectivity in vitro in transient co-transfected HEK293 cells expressing C57BL/6J (B6) and 129S1/SvImJ (129S) Vwf. Of those siRNAs three lead candidates were chosen. These candidates, a non-selective siVwf, and two strain-selective siRNAs (siVwf.B6 and siVwf.129S), together with corresponding scrambled controls were encapsulated in 7C1 polymeric nanoparticles for endothelial targeting in vivo. Male and female B6 and 129S mice were intravenously injected with the siRNA-encapsulated nanoparticles. 72 hours post-injection, citrated blood and lung tissue were collected for measuring VWF plasma protein and Vwf mRNA expression, respectively.
Results: For both male and female mice, all three lead candidate siRNAs dose-dependently inhibited Vwf expression on mRNA and plasma protein levels in the corresponding mouse strains (Figure 1). The highest inhibitory effect was shown at the dose of 1.5 mg siRNA/kg body weight. The median inhibition was 70% [63-95] on lung mRNA and 75% [66-82] on plasma levels for siVwf-treated mice, 87% [85-90] and 83% [80-86] for siVwf.B6-treated mice, and 70% [54-79] and 62% [51-72] for siVwf.129S-treated mice.
Conclusion(s): We have shown efficient in vivo endothelial targeting of strain-selective siRNAs with up to 90% inhibition of Vwf in corresponding mouse strains. Testing of these siRNAs in F1 hybrids of B6x129S mice for allele-selectivity is currently ongoing. This study was financially supported by the Dutch Thrombosis Foundation (grant #2018-1).
Figure 1.
Murine Vwf lung mRNA and plasma protein levels 72 hours post-injection with different siRNA doses. -A- Vwf mRNA expression in C57BL/6J -B6- and 129S1/SvImJ -129S- mice after treatment with 0.5-1-1.5 mg siVwf/kg body weight. -B- Vwf mRNA expression in B6 mice after treatment with 0.5-1-1.5 mg siVwf.B6/kg body weight. -C- Vwf mRNA expression in 129S mice after treatment with 0.5-1-1.5 mg siVwf.129S/kg body weight. -D- Plasma VWF levels in B6 and 129S mice after treatment with 0.5-1-1.5 mg siVwf/kg body weight. -E- Plasma VWF levels in B6 mice after treatment with 0.5-1-1.5 mg siVwf.B6/kg body weight. -F- Plasma VWF levels in 129S mice after treatment with 0.5-1-1.5 mg siVwf.129S/kg body weight. Data presented as individual datapoints -Nf4-6 animals- with median percentage of scrambled control siRNA per treatment group. Statistical analysis was performed using a two-tailed Mann-Whitney test with * = P < 0.05, ** = P < 0.01, *** = P < 0.001 and **** = P < 0.0001.
To cite this abstract in AMA style:
Jongejan Y, Dirven R, Paunovska K, Linthorst N, Schrader E, van der Gouw K, de Jong A, Dahlman J, van Vlijmen B, Eikenboom J. Allele-selective inhibition of murine von Willebrand factor in vitro and in vivo [abstract]. https://abstracts.isth.org/abstract/allele-selective-inhibition-of-murine-von-willebrand-factor-in-vitro-and-in-vivo/. Accessed October 1, 2023.« Back to ISTH 2022 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/allele-selective-inhibition-of-murine-von-willebrand-factor-in-vitro-and-in-vivo/