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RNAi modulation of placental sFLT1 for the treatment of preeclampsia

Abstract

Preeclampsia is a placentally induced hypertensive disorder of pregnancy that is associated with substantial morbidity and mortality to mothers and fetuses. Clinical manifestations of preterm preeclampsia result from excess circulating soluble vascular endothelial growth factor receptor FLT1 (sFLT1 or sVEGFR1) of placental origin. Here we identify short interfering RNAs (siRNAs) that selectively silence the three sFLT1 mRNA isoforms primarily responsible for placental overexpression of sFLT1 without reducing levels of full-length FLT1 mRNA. Full chemical stabilization in the context of hydrophobic modifications enabled productive siRNA accumulation in the placenta (up to 7% of injected dose) and reduced circulating sFLT1 in pregnant mice (up to 50%). In a baboon preeclampsia model, a single dose of siRNAs suppressed sFLT1 overexpression and clinical signs of preeclampsia. Our results demonstrate RNAi-based extrahepatic modulation of gene expression with nonformulated siRNAs in nonhuman primates and establish a path toward a new treatment paradigm for patients with preterm preeclampsia.

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Figure 1: Development of hydrophobically modified, chemically stabilized hsiRNA compounds against sFLT1.
Figure 2: Efficient silencing of sFLT1 by hsiRNAsFLT1-2283/2519 mixture in vitro.
Figure 3: Full chemical stabilization of cholesterol-conjugated hsiRNAs enables systemic delivery to placental labyrinth.
Figure 4: Efficient silencing of sFlt1 mRNA and protein by hsiRNAsFLT1 in pregnant mice.
Figure 5: hsiRNAsFLT1-2283/2519 treatment lowers sFLT1 serum levels and normalizes blood pressure and proteinuria in a baboon model of preeclampsia.

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References

  1. Stevens, W. et al. Short-term costs of preeclampsia to the United States health care system. Am. J. Obstet. Gynecol. 217, 237–248.e216 (2017).

    PubMed  Google Scholar 

  2. Maynard, S.E. et al. Excess placental soluble fms-like tyrosine kinase 1 (sFlt1) may contribute to endothelial dysfunction, hypertension, and proteinuria in preeclampsia. J. Clin. Invest. 111, 649–658 (2003).

    CAS  PubMed  PubMed Central  Google Scholar 

  3. Levine, R.J. et al. Circulating angiogenic factors and the risk of preeclampsia. N. Engl. J. Med. 350, 672–683 (2004).

    CAS  PubMed  Google Scholar 

  4. Heydarian, M. et al. Novel splice variants of sFlt1 are upregulated in preeclampsia. Placenta 30, 250–255 (2009).

    CAS  PubMed  Google Scholar 

  5. Young, B.C., Levine, R.J. & Karumanchi, S.A. Pathogenesis of preeclampsia. Annu. Rev. Pathol. 5, 173–192 (2010).

    CAS  PubMed  Google Scholar 

  6. Aubuchon, M., Schulz, L.C. & Schust, D.J. Preeclampsia: animal models for a human cure. Proc. Natl. Acad. Sci. USA 108, 1197–1198 (2011).

    CAS  PubMed  PubMed Central  Google Scholar 

  7. Chaiworapongsa, T. et al. Evidence supporting a role for blockade of the vascular endothelial growth factor system in the pathophysiology of preeclampsia. Am. J. Obstet. Gynecol. 190, 1541–1547; discussion 1547–1550 (2004).

    CAS  PubMed  Google Scholar 

  8. Lu, F. et al. The effect of over-expression of sFlt-1 on blood pressure and the occurrence of other manifestations of preeclampsia in unrestrained conscious pregnant mice. Am. J. Obstet. Gynecol. 196, 396 e391–397; discussion 396 e397 (2007).

    PubMed  Google Scholar 

  9. Ahmad, S. & Ahmed, A. Elevated placental soluble vascular endothelial growth factor receptor-1 inhibits angiogenesis in preeclampsia. Circ. Res. 95, 884–891 (2004).

    CAS  PubMed  Google Scholar 

  10. Redman, C.W. & Sargent, I.L. Latest advances in understanding preeclampsia. Science 308, 1592–1594 (2005).

    CAS  PubMed  Google Scholar 

  11. Vorlová, S. et al. Induction of antagonistic soluble decoy receptor tyrosine kinases by intronic polyA activation. Mol. Cell 43, 927–939 (2011).

    PubMed  PubMed Central  Google Scholar 

  12. Kendall, R.L. & Thomas, K.A. Inhibition of vascular endothelial cell growth factor activity by an endogenously encoded soluble receptor. Proc. Natl. Acad. Sci. USA 90, 10705–10709 (1993).

    CAS  PubMed  PubMed Central  Google Scholar 

  13. Bujold, E. et al. Evidence supporting that the excess of the sVEGFR-1 concentration in maternal plasma in preeclampsia has a uterine origin. J. Matern. Fetal Neonatal Med. 18, 9–16 (2005).

    CAS  PubMed  Google Scholar 

  14. Zeisler, H. et al. Predictive value of the sFlt-1:PlGF ratio in women with suspected preeclampsia. N. Engl. J. Med. 374, 13–22 (2016).

    CAS  PubMed  Google Scholar 

  15. Sunderji, S. et al. Automated assays for sVEGF R1 and PlGF as an aid in the diagnosis of preterm preeclampsia: a prospective clinical study. Am. J. Obstet. Gynecol. 202, 40 e41–47 (2010).

    PubMed  Google Scholar 

  16. Rana, S. et al. Angiogenic factors and the risk of adverse outcomes in women with suspected preeclampsia. Circulation 125, 911–919 (2012).

    CAS  PubMed  PubMed Central  Google Scholar 

  17. Chaiworapongsa, T. et al. Plasma concentrations of angiogenic/anti-angiogenic factors have prognostic value in women presenting with suspected preeclampsia to the obstetrical triage area: a prospective study. J. Matern. Fetal Neonatal Med. 27, 132–144 (2014).

    CAS  PubMed  Google Scholar 

  18. Thadhani, R. et al. Pilot study of extracorporeal removal of soluble fms-like tyrosine kinase 1 in preeclampsia. Circulation 124, 940–950 (2011).

    CAS  PubMed  Google Scholar 

  19. Thadhani, R. et al. Removal of soluble fms-like tyrosine kinase-1 by dextran sulfate apheresis in preeclampsia. J. Am. Soc. Nephrol. 27, 903–913 (2016).

    CAS  PubMed  Google Scholar 

  20. Khvorova, A. & Watts, J.K. The chemical evolution of oligonucleotide therapies of clinical utility. Nat. Biotechnol. 35, 238–248 (2017).

    CAS  PubMed  PubMed Central  Google Scholar 

  21. Fitzgerald, K. et al. A highly durable RNAi therapeutic inhibitor of PCSK9. N. Engl. J. Med. 376, 41–51 (2017).

    CAS  PubMed  Google Scholar 

  22. Khvorova, A. Oligonucleotide therapeutics – a new class of cholesterol-lowering drugs. N. Engl. J. Med. 376, 4–7 (2017).

    CAS  PubMed  Google Scholar 

  23. Haraszti, R.A. et al. 5′-Vinylphosphonate improves tissue accumulation and efficacy of conjugated siRNAs in vivo. Nucleic Acids Res. 45, 7581–7592 (2017).

    CAS  PubMed  PubMed Central  Google Scholar 

  24. Soutschek, J. et al. Therapeutic silencing of an endogenous gene by systemic administration of modified siRNAs. Nature 432, 173–178 (2004).

    CAS  PubMed  Google Scholar 

  25. Byrne, M. et al. Novel hydrophobically modified asymmetric RNAi compounds (sd-rxRNA) demonstrate robust efficacy in the eye. J. Ocul. Pharmacol. Ther. 29, 855–864 (2013).

    CAS  PubMed  Google Scholar 

  26. Khan, T. et al. Silencing myostatin using cholesterol-conjugated siRNAs induces muscle growth. Mol. Ther. Nucleic Acids 5, e342 (2016).

    CAS  PubMed  PubMed Central  Google Scholar 

  27. Hassler, M.R. et al. Comparison of partially and fully chemically-modified siRNA in conjugate-mediated delivery in vivo. Nucleic Acids Res. 46, 2185–2196 (2018).

    CAS  PubMed  PubMed Central  Google Scholar 

  28. Ashar-Patel, A. et al. FLT1 and transcriptome-wide polyadenylation site (PAS) analysis in preeclampsia. Sci. Rep. 7, 12139 (2017).

    PubMed  PubMed Central  Google Scholar 

  29. Palmer, K.R. et al. Placental-specific sFLT-1 e15a protein is increased in preeclampsia, antagonizes vascular endothelial growth factor signaling, and has antiangiogenic activity. Hypertension 66, 1251–1259 (2015).

    CAS  PubMed  Google Scholar 

  30. Souders, C.A. et al. Circulating levels of sFlt1 splice variants as predictive markers for the development of preeclampsia. Int. J. Mol. Sci. 16, 12436–12453 (2015).

    CAS  PubMed  PubMed Central  Google Scholar 

  31. Birmingham, A. et al. A protocol for designing siRNAs with high functionality and specificity. Nat. Protoc. 2, 2068–2078 (2007).

    CAS  PubMed  Google Scholar 

  32. Anderson, E.M. et al. Experimental validation of the importance of seed complement frequency to siRNA specificity. RNA 14, 853–861 (2008).

    CAS  PubMed  PubMed Central  Google Scholar 

  33. Khvorova, A., Reynolds, A. & Jayasena, S.D. Functional siRNAs and miRNAs exhibit strand bias. Cell 115, 209–216 (2003).

    CAS  PubMed  Google Scholar 

  34. Schwarz, D.S. et al. Asymmetry in the assembly of the RNAi enzyme complex. Cell 115, 199–208 (2003).

    CAS  PubMed  Google Scholar 

  35. Alterman, J.F. et al. Hydrophobically modified siRNAs silence huntingtin mRNA in primary neurons and mouse brain. Mol. Ther. Nucleic Acids 4, e266 (2015).

    CAS  PubMed  PubMed Central  Google Scholar 

  36. Godinho, B.M.D.C. et al. Pharmacokinetic profiling of conjugated therapeutic oligonucleotides: a high-throughput method based upon serial blood microsampling coupled to peptide nucleic acid hybridization assay. Nucleic Acid Ther. 27, 323–334 (2017).

    CAS  PubMed  PubMed Central  Google Scholar 

  37. Ly, S. et al. Visualization of self-delivering hydrophobically modified siRNA cellular internalization. Nucleic Acids Res. 45, 15–25 (2017).

    CAS  PubMed  Google Scholar 

  38. Wang, S. et al. Cellular uptake mediated by epidermal growth factor receptor facilitates the intracellular activity of phosphorothioate-modified antisense oligonucleotides. Nucleic Acids Res. 46, 3579–3594 (2018).

    CAS  PubMed  PubMed Central  Google Scholar 

  39. Allerson, C.R. et al. Fully 2′-modified oligonucleotide duplexes with improved in vitro potency and stability compared to unmodified small interfering RNA. J. Med. Chem. 48, 901–904 (2005).

    CAS  PubMed  Google Scholar 

  40. Sela, S. et al. A novel human-specific soluble vascular endothelial growth factor receptor 1: cell-type-specific splicing and implications to vascular endothelial growth factor homeostasis and preeclampsia. Circ. Res. 102, 1566–1574 (2008).

    CAS  PubMed  Google Scholar 

  41. Holme, A.M., Roland, M.C., Henriksen, T. & Michelsen, T.M. In vivo uteroplacental release of placental growth factor and soluble Fms-like tyrosine kinase-1 in normal and preeclamptic pregnancies. Am. J. Obstet. Gynecol. 215, 782 e781–782 e789 (2016).

    PubMed  Google Scholar 

  42. Rajakumar, A. et al. Transcriptionally active syncytial aggregates in the maternal circulation may contribute to circulating soluble fms-like tyrosine kinase 1 in preeclampsia. Hypertension 59, 256–264 (2012).

    CAS  PubMed  Google Scholar 

  43. Makris, A. et al. Uteroplacental ischemia results in proteinuric hypertension and elevated sFLT-1. Kidney Int. 71, 977–984 (2007).

    CAS  PubMed  Google Scholar 

  44. Amadio, M., Govoni, S. & Pascale, A. Targeting VEGF in eye neovascularization: what's new?: a comprehensive review on current therapies and oligonucleotide-based interventions under development. Pharmacol. Res. 103, 253–269 (2016).

    CAS  PubMed  Google Scholar 

  45. Ambati, B.K. et al. Corneal avascularity is due to soluble VEGF receptor-1. Nature 443, 993–997 (2006).

    CAS  PubMed  PubMed Central  Google Scholar 

  46. Lertkiatmongkol, P., Liao, D., Mei, H., Hu, Y. & Newman, P.J. Endothelial functions of platelet/endothelial cell adhesion molecule-1 (CD31). Curr. Opin. Hematol. 23, 253–259 (2016).

    CAS  PubMed  PubMed Central  Google Scholar 

  47. Karumanchi, S.A. Angiogenic factors in preeclampsia: from diagnosis to therapy. Hypertension 67, 1072–1079 (2016).

    CAS  PubMed  Google Scholar 

  48. Bergmann, A. et al. Reduction of circulating soluble Flt-1 alleviates preeclampsia-like symptoms in a mouse model. J. Cell. Mol. Med. 14 6B, 1857–1867 (2010).

    PubMed  PubMed Central  Google Scholar 

  49. Spradley, F.T. et al. Placental growth factor administration abolishes placental ischemia-induced hypertension. Hypertension 67, 740–747 (2016).

    CAS  PubMed  Google Scholar 

  50. Makris, A. et al. Placental growth factor reduces blood pressure in a uteroplacental ischemia model of preeclampsia in nonhuman primates. Hypertension 67, 1263–1272 (2016).

    CAS  PubMed  Google Scholar 

  51. Yu, D. et al. Single-stranded RNAs use RNAi to potently and allele-selectively inhibit mutant huntingtin expression. Cell 150, 895–908 (2012).

    CAS  PubMed  PubMed Central  Google Scholar 

  52. Nair, J.K. et al. Impact of enhanced metabolic stability on pharmacokinetics and pharmacodynamics of GalNAc-siRNA conjugates. Nucleic Acids Res. 45, 10969–10977 (2017).

    CAS  PubMed  PubMed Central  Google Scholar 

  53. Pasi, K.J. et al. Targeting of antithrombin in hemophilia A or B with RNAi therapy. N. Engl. J. Med. 377, 819–828 (2017).

    CAS  PubMed  Google Scholar 

  54. Matsuda, S. et al. siRNA conjugates carrying sequentially assembled trivalent N-acetylgalactosamine linked through nucleosides elicit robust gene silencing in vivo in hepatocytes. ACS Chem. Biol. 10, 1181–1187 (2015).

    CAS  PubMed  Google Scholar 

  55. Nair, J.K. et al. Multivalent N-acetylgalactosamine-conjugated siRNA localizes in hepatocytes and elicits robust RNAi-mediated gene silencing. J. Am. Chem. Soc. 136, 16958–16961 (2014).

    CAS  PubMed  Google Scholar 

  56. Wolfrum, C. et al. Mechanisms and optimization of in vivo delivery of lipophilic siRNAs. Nat. Biotechnol. 25, 1149–1157 (2007).

    CAS  PubMed  Google Scholar 

  57. Krützfeldt, J. et al. Silencing of microRNAs in vivo with 'antagomirs'. Nature 438, 685–689 (2005).

    PubMed  Google Scholar 

  58. Baerlocher, G.M., Burington, B. & Snyder, D.S. Telomerase inhibitor imetelstat in essential thrombocythemia and myelofibrosis. N. Engl. J. Med. 373, 2580 (2015).

    PubMed  Google Scholar 

  59. Yu, J., Jia, J., Guo, X., Chen, R. & Feng, L. Modulating circulating sFlt1 in an animal model of preeclampsia using PAMAM nanoparticles for siRNA delivery. Placenta 58, 1–8 (2017).

    PubMed  Google Scholar 

  60. Khankin, E.V., Mandala, M., Colton, I., Karumanchi, S.A. & Osol, G. Hemodynamic, vascular, and reproductive impact of FMS-like tyrosine kinase 1 (FLT1) blockade on the uteroplacental circulation during normal mouse pregnancy. Biol. Reprod. 86, 57 (2012).

    PubMed  Google Scholar 

  61. Yu, R.Z. et al. Cross-species pharmacokinetic comparison from mouse to man of a second-generation antisense oligonucleotide, ISIS 301012, targeting human apolipoprotein B-100. Drug Metab. Dispos. 35, 460–468 (2007).

    CAS  PubMed  Google Scholar 

  62. Geary, R.S., Norris, D., Yu, R. & Bennett, C.F. Pharmacokinetics, biodistribution and cell uptake of antisense oligonucleotides. Adv. Drug Deliv. Rev. 87, 46–51 (2015).

    CAS  PubMed  Google Scholar 

  63. Savage, V.M. et al. Scaling of number, size, and metabolic rate of cells with body size in mammals. Proc. Natl. Acad. Sci. USA 104, 4718–4723 (2007).

    CAS  PubMed  PubMed Central  Google Scholar 

  64. Fan, X. et al. Endometrial VEGF induces placental sFLT1 and leads to pregnancy complications. J. Clin. Invest. 124, 4941–4952 (2014).

    CAS  PubMed  PubMed Central  Google Scholar 

  65. Anderson, E., Boese, Q., Khvorova, A. & Karpilow, J. Identifying siRNA-induced off-targets by microarray analysis. Methods Mol. Biol. 442, 45–63 (2008).

    CAS  PubMed  Google Scholar 

  66. Osborn, M.F. et al. Guanabenz (Wytensin™) selectively enhances uptake and efficacy of hydrophobically modified siRNAs. Nucleic Acids Res. 43, 8664–8672 (2015).

    CAS  PubMed  PubMed Central  Google Scholar 

  67. Rajakumar, A. et al. Novel soluble Flt-1 isoforms in plasma and cultured placental explants from normotensive pregnant and preeclamptic women. Placenta 30, 25–34 (2009).

    CAS  PubMed  Google Scholar 

  68. Coles, A.H. et al. A high-throughput method for direct detection of therapeutic oligonucleotide-induced gene silencing in vivo. Nucleic Acid Ther. 26, 86–92 (2016).

    CAS  PubMed  PubMed Central  Google Scholar 

  69. Nikan, M. et al. Docosahexaenoic acid conjugation enhances distribution and safety of siRNA upon local administration in mouse brain. Mol. Ther. Nucleic Acids 5, e344 (2016).

    CAS  PubMed  PubMed Central  Google Scholar 

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Acknowledgements

We thank D. Conte for help revising the manuscript and Khvorova Laboratory members for their support. This project was funded by the National Institutes of Health (R01 HD086111 and S10 OD020012) and the Bill and Melinda Gates Foundation (OPP1086170).

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Authors and Affiliations

Authors

Contributions

A.A.T. managed the project, performed most of the experiments and drafted the manuscript. M.J.M., S.A.K. and A.K. conceived the study and led the project. M.R.H., D.E. and L.R. synthesized all compounds and developed and optimized protocols for gram-scale synthesis. A.H.C. and B.M.D.C.G. helped with in vivo studies. R.A.H. performed PNA assay analysis. A.A.-P. performed polyadenylation site sequence analysis and an initial siRNA screen. J.F.A. helped with the siRNA screen. A.L. performed primary cytotrophoblast isolations, ELISAs, toxicity studies and mouse pregnancy studies. Z.K.Z. performed placenta vascular immunohistochemistry. A.H., A.M., S.P., J.I., R.S. and R.O. developed the baboon preeclampsia model and performed all baboon experiments. A.A.T, A.K., M.J.M., S.A.K. and A.H. wrote the manuscript.

Corresponding authors

Correspondence to S Ananth Karumanchi, Melissa J Moore or Anastasia Khvorova.

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Competing interests

A.K. discloses ownership of stock in RXi Pharmaceuticals and Advirna. S.A.K. is a consultant to Thermofisher Scientific and owns stock in Aggamin Therapeutics. M.J.M. is employed by Moderna Therapeutics.

Integrated supplementary information

Supplementary Figure 1 Upregulation of alternative sFLT1 mRNAs in human placentas in preeclampsia.

Total RNA was isolated from 6 normal (N) and 11 preeclamptic (PE) human placentas and analyzed by Polyadenylation Site sequencing (PAS-Seq). Data for computation were derived from (Ashar et al, 2017). All three sFLT1 mRNA isoforms are contributing to sFLT1 overexpression during PE.

Supplementary Figure 2 Specific hsiRNA-mediated downregulation of sFLT1 mRNA isoforms in human placental cytotrophoblast (CTB).

a) Dose-response curves of hsiRNAPPIB silencing of PPIB mRNA in CTB (n=3 biologically independent experiments, mean +SD). b) Dose-response curves of hsiRNAsFLT1-2283 and hsiRNAsFLT1-2519 silencing of sFLT1-i13 and sFLT1-e15a mRNAs in CTB (n=3 biologically independent experiments, mean + s.d.). hsiRNANTC – non-targeting hsiRNA control. ****P<0.0001, **P<0.01, *P<0.05, two-way ANOVA.

Supplementary Figure 3 Full chemical stabilization of cholesterol-conjugated hsiRNAsFLT1-2283 enables efficient placenta accumulation.

a) Representative images of placenta distribution (24 hours post treatment) of partially and fully modified Cy3-hsiRNAsFLT1-2283 (red) following 10 mg/kg IV or SC injections. Nuclei stained with DAPI (blue). Scale bar, 1mm. All images were acquired at identical settings (n=3 biologically independent animals). b) Guide strand quantification by PNA hybridization-based assay in placentas from a (n=6 biologically independent samples). Boxes represent 25 to 75 percentiles and whiskers indicate minimal and maximal values (****P<0.0001, **P=0.015, unpaired t test, two-tailed).

Supplementary Figure 4 Efficient silencing of sFLT1 mRNA in liver and kidney by hsiRNAsFLT1-2283 in pregnant mice.

Pregnant CD1 mice were injected at day E14 and E15 with 2X20 mg/kg of hsiRNAsFLT1 -2283 (IV, tail vein) and sacrificed at day E19. a) sFLT1-i13 mRNA levels were measured using QuantiGene® assay (Affymetrix), normalized to housekeeping gene, and presented as % of PBS control (n=6 biologically independent animals, mean + s.d., ****P<0.0001, one-way ANOVA). b) Amount of guide strand accumulated in mouse tissues measured by PNA hybridization assay (n=6 biologically independent samples, boxes represent 25 to 75 percentiles and whiskers indicate minimal and maximal values, ****P<0.0001, one-way ANOVA).

Supplementary Figure 5 Newborn pup numbers and weights from pregnant mice treated with hsiRNA.

Pregnant CD1 mice were injected at day E14 and E15 with 2X20 mg/kg of hsiRNAsFLT1-2283, hsiRNANTC or PBS (IV, tail vein) and allowed to deliver pups on day E20. a-c). Newborn pups number and weights from mice injected with PBS or hsiRNAsFLT1 -2283 (n=9 biologically independent animals, boxes represent 25 to 75 percentiles and whiskers indicate minimal and maximal values, ns- non-significant, unpaired t test, two-tailed). d-e) Newborn pups number and weights from mice injected with PBS or hsiRNANTC (n=10 biologically independent animals, boxes represent 25 to 75 percentiles and whiskers indicate minimal and maximal values, ns- non-significant, unpaired t test, two-tailed).

Supplementary Figure 6 Efficient sFLT1 mRNA cleavage by hsiRNAsFLT1-2283 in mouse placenta (5′-RACE analysis).

Pregnant CD1 mice were injected at E14 and E15 with 2X20 mg/kg of hsiRNAsFLT1 -2283, hsiRNANTC or PBS (IV, tail vein) and sacrificed at E19. Total RNA was isolated from whole placenta and agarose gel of 5’-RACE PCR amplification with GR1 and GSP1 primers showed predicted cleavage product (~400 bp, indicated by Arrow). Representative image from two independent experiments. Corresponding sequencing result shown below.

Supplementary Figure 7 hsiRNAsFLT1-2283/2519 tissue concentrations after IV injection in pregnant mice.

Pregnant mice were injected with 2x20 mg/kg of hsiRNAsFLT1-2283/2519 at day E14 and E15 and tissues were collected at day E19. Milk was collected at post partum day P12. Guide strand concentration hsiRNAsFLT1-2283 and hsiRNAsFLT1-2519 were measured using PNA hybridization assay (n=2 biologically independent animals, mean +s.d.). # - milk samples concentrations are presented in ng/μl.

Supplementary Figure 8 Representative placental histology of mice treated with PBS, hsiRNA 2383 and 2283/2519 (2 × 20 mg/kg, IV, n = 4), showing anti-CD31 staining.

PBS treated placental labyrinth shows extensive staining for CD31 (upper panel), suggesting robust vascular network. Under higher magnifications (lower panel), PBS treated placental tissue displays small vessels filled with nucleated erythrocytes in close vicinity to maternal blood sinuses. There were no significant changes in the hsiRNA injected mice. D- decidua, Jz - junctional zone and L – labyrinth.

Supplementary Figure 9 Newborn baboon weights and centiles after hsiRNAsFLT1 treatment.

Pregnant baboons were injected with 20 mg/kg of hsiRNAsFLT1-2283/2519 around day 133 of gestation and newborns’ weights and centiles were recorded after delivery. ns- non-significant (n=9 biologically independent animals for control, n=3 for hsiRNA, P=0.1819, unpaired t test, two-tailed, boxes represent 25 to 75 percentiles and whiskers indicate minimal and maximal values). * - pregnancy was terminated before full term for unrelated conditions.

Supplementary Figure 10 hsiRNAsFLT1-2283/2519 blood, placenta and urine concentrations following a single IV injection in the baboon model of PE.

Pregnant baboons were injected with 20 mg/kg of hsiRNAsFLT1-2283/2519 around day 133 of gestation. Blood, urine and placenta biopsies were collected at the time points shows. Guide strand concentration hsiRNAsFLT1-2283 and hsiRNAsFLT1-2519 were measured using PNA hybridization assay (n=1).

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Chemical modification patterns and sequences of siRNAs (PDF 407 kb)

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Turanov, A., Lo, A., Hassler, M. et al. RNAi modulation of placental sFLT1 for the treatment of preeclampsia. Nat Biotechnol 36, 1164–1173 (2018). https://doi.org/10.1038/nbt.4297

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