Targeting Ras GTPases in Murine Models of Renal Fibrosis

    Student thesis: Doctoral ThesisDoctor of Philosophy

    Abstract

    End stage kidney disease (ESKD) affects over! 53,00 people. The progression of
    chronic kidney disease (CKD) to ESKD is characterised by cytokine stimulation,!
    leading to the activation of myofibroblasts, resulting in fibrosis. Kirsten rat sarcoma (KNRas) has a key role in the proliferation of renal fibroblasts in vitro and has been highlighted as a possible target for fibrosis.Previous research in our laboratory showed that inhibiting KNRas in the UUO model inhibited renal!fibrosis.
    The aim of this thesis was to investigate the outcome of inhibiting KNRas using
    Antisense Oligonucleotide (ASO) in the novel Chronic Folic Acid Nephropathy!
    (CFAN) model to study the effect on both fibrosis and renal function. The effect of inhibiting KNRas was also investigated in vitro, to try and elucidate the mechanism by which KNRas controls the progression of fibrosis.
    KNRas knockdown with ASO143 resulted in 50% reduction in KNRas mRNA which was associated with: 37%-50% reduction in total collagen and protection of renal
    function (BUN) in the 12 week CFAN model. TGFβ1 treated cells showed an upN
    regulation i !KNRas, Jag1 and Collagen 1a mRNA. Treatment with KNRas ASO was
    associated with a 3.5 fold reduction in Jag 1 and a 55% reduction in collagen 1a. Jag 1 has been linked to the progression of renal fibrosis via biNdirectional signalling with Notch 1.
    In conclusion, ASO knockdown of KNRas inhibits fibrosis in vitro and in vivo, and in some instances protects renal function. These results support the hypothesis that KNRas targeting may be beneficial in the treatment of renal fibrosis. Further work is required to further understand the relationship between Jag 1,Notch 1 and KNRas, but this data suggests that KNRas affects renal fibrosis in a Jag 1 dependent pathway.
    Date of Award2015
    Original languageEnglish
    Awarding Institution
    • King's College London
    SupervisorBruce Hendry (Supervisor) & Claire Sharpe (Supervisor)

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