The Inflammatory Bowel Disease Drug Azathioprine Induces Autophagy via mTORC1 and the Unfolded Protein Response Sensor PERK

KM Hooper, V Casanova, S Kemp, KA Staines, J Satsangi, PG Barlow, P Henderson, C Stevens

    Research output: Contribution to journalArticlepeer-review


    BACKGROUND: Genetic studies have strongly linked autophagy to Crohn's disease (CD), and stimulating autophagy in CD patients may be therapeutically beneficial. The aim of this study was to evaluate the effect of current inflammatory bowel disease (IBD) drugs on autophagy and investigate molecular mechanisms of action and functional outcomes in relation to this cellular process. METHODS: Autophagy marker LC3 was evaluated by confocal fluorescence microscopy and flow cytometry. Drug mechanism of action was investigated by polymerase chain reaction (PCR) array with changes in signaling pathways examined by immunoblot and quantitative reverse transcription PCR (RT-qPCR). Clearance of adherent-invasive Escherichia coli (AIEC) and levels of pro-inflammatory cytokine tumor necrosis factor alpha (TNFα) were evaluated by gentamicin protection assays and RT-qPCR, respectively. The marker LC3 was analyzed in peripheral blood mononuclear cells (PBMCs) from pediatric patients by flow cytometry. RESULTS: Azathioprine induces autophagy via mechanisms involving modulation of mechanistic target of rapamycin (mTORC1) signaling and stimulation of the unfolded protein response (UPR) sensor PERK. Induction of autophagy with azathioprine correlated with the enhanced clearance of AIEC and dampened AIEC-induced increases in TNFα. Azathioprine induced significant increase in autophagosome bound LC3-II in PBMC populations ex vivo, supporting in vitro findings. In patients, the CD-associated ATG16L1 T300A single-nucleotide polymorphism did not attenuate azathioprine induction of autophagy. CONCLUSIONS: Modulation of autophagy via mTORC1 and the UPR may contribute to the therapeutic efficacy of azathioprine in IBD.

    Original languageEnglish
    Pages (from-to)1481-1496
    Number of pages16
    JournalInflammatory bowel diseases
    Issue number9
    Publication statusPublished - 19 Mar 2019


    • Azathioprine
    • adherent-invasive E. coli
    • autophagy
    • mTORC1
    • unfolded protein response


    Dive into the research topics of 'The Inflammatory Bowel Disease Drug Azathioprine Induces Autophagy via mTORC1 and the Unfolded Protein Response Sensor PERK'. Together they form a unique fingerprint.

    Cite this