Gene Silencing with p53 si-RNA Downregulates Inflammatory Markers in the Liver: Potential Utilization during Normothermic Machine Preservation

C. Moore,¹ M. Thijssen,^1,2 X. Wang,³ P. Mandrekar,³ E. Xiaofei,³ R. Abdi,⁴ R. Porte,² A. Bozorgzadeh,¹ H. Leuvenink,² T. Kowalik,³ P. Martins.¹

¹Dept of Surgery, University of Massachusetts, Worcester, MA
²Dept of Surgery, Groningen University, Gronigen, Netherlands
³Dept of Medicine, Univ. of Massachusetts, Worcester, MA
⁴Transplant Research Institute, Harvard University, Boston, MA.

Meeting: 2018 American Transplant Congress

Abstract number: A79

Keywords: Inflammation, Ischemia, Liver preservation, Machine preservation

Session Information

Session Name: Poster Session A: Innate Immunity; Chemokines, Cytokines, Complement

Session Type: Poster Session

Date: Saturday, June 2, 2018

Session Time: 5:30pm-7:30pm

Presentation Time: 5:30pm-7:30pm

Location: Hall 4EF

Background: RNA interference (RNAi) is a process through which RNA induces the activation of endogenous cellular pathways of RNA degradation, resulting in selective and potent silencing of genes post-transcriptionally. Ischemia Reperfusion Injury (IRI) has a major impact on liver graft outcome. The cellular stress suffered IRI can trigger the expression of p53 tumor suppressor gene that will induce apoptosis. By temporarily silencing the p53 gene, our study aimed to protect the liver against the detrimental effects of IRI and determine siRNA up-taken during machine perfusion preservation.

Methods: Rats were injected iv with 10 nmol of cy3-labeled p53 siRNA, using Invivofectamine as a transfection agent, one day prior to inducing liver damage. Liver damage was induced by clamping liver hilum for 15 min. The control group did not receive siRNA. After 3 days the rats were euthanized and tissue and blood samples were analyzed. We also checked the uptake of the same siRNA in naïve livers after 6 hours of ex-vivo normothermic liver perfusion preservation.

Results: Confocal microscopy of livers treated with p53 siRNA-cy3 during machine preservation showed positive fluorescence for cy-3, showing that siRNA is capable to reach and penetrate liver cells. HE staining showed the livers from animals treated with p53 siRNA-cy3 presented less vacuolization and less cell infiltration compared to the control group. Immunofluorescence for p53 showed less positive cells in p53 siRNA-cy3 compared to non-treated animals, showing the effectiveness of the siRNA. Inflammatory cytokines (IL-1, IL-6, and TNFa), neutrophil infiltration, and lipoperoxidation presented lower levels in p53-siRNA treated animals compared to controls. flow cytometry analysis showed that p53 siRNA had no effect on the relative distribution of immune cell populations such as total lymphocytes, CD4, CD8, NK cells, neutrophils, monocytes and B cells).

Conclusions: Silencing the p53 gene is a potential therapeutic option to alleviate liver IRI. Ex-vivo normothermic machine perfusion can be used as a non-systemic therapy delivery method of siRNAs.

CITATION INFORMATION: Moore C., Thijssen M., Wang X., Mandrekar P., Xiaofei E., Abdi R., Porte R., Bozorgzadeh A., Leuvenink H., Kowalik T., Martins P. Gene Silencing with p53 si-RNA Downregulates Inflammatory Markers in the Liver: Potential Utilization during Normothermic Machine Preservation Am J Transplant. 2017;17 (suppl 3).

To cite this abstract in AMA style:

Moore C, Thijssen M, Wang X, Mandrekar P, Xiaofei E, Abdi R, Porte R, Bozorgzadeh A, Leuvenink H, Kowalik T, Martins P. Gene Silencing with p53 si-RNA Downregulates Inflammatory Markers in the Liver: Potential Utilization during Normothermic Machine Preservation [abstract]. https://atcmeetingabstracts.com/abstract/gene-silencing-with-p53-si-rna-downregulates-inflammatory-markers-in-the-liver-potential-utilization-during-normothermic-machine-preservation/. Accessed May 13, 2025.

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