Drug induced intestinal goblet cell metaplasia: a novel assay to screen and select safe compounds using gut epithelial organoid models
Natascha Santacroce, Nick Pearson, Adrian B. Roth, Cristina Bertinetti-Lapatki
Roche Pharmaceutical Research & Early Development (pRED), Pharmaceutical Sciences, Roche Innovation Center Basel, Basel, Switzerland
The intestinal epithelium is composed of single layer of several distinct cell types that are continuously renewed (every 4-5 days) from stem cells located in the intestinal crypts. Intestinal stem cells give rise to rapidly proliferating transit-amplifying cells that differentiate near the top of the crypts into the mature cells of the gut. These new mature cells migrate upwards into the villi and are eventually sloughed into the lumen. Among the various pathways that regulate proliferation and differentiation of the intestinal cells, the Notch signaling cascade is key in modulating stem cell renewal and differentiation.
When isolated LGR5+ gut stem cells are cultured in 3D they self-organize into epithelial organoids (“mini-guts”). These organoids retain the hallmarks of the in vivo gut epithelium and have been extensively used to investigate the signaling events that drive the differentiation of the stem cells into the different cell types that constitute the intestinal epithelium.
Active Notch signaling results in the expression of the target gene Hes1, the loss of which results in increased secretory lineage differentiation and decreased production of absorptive enterocytes. Expression of Hes1 also results in the repression of Atoh1, which drives cells into Goblet or Paneth cell secretory lineages in the absence of Notch signaling. The downmodulation / inhibition of the Notch signaling cascade as a result of off-target drug activities may result in an increased risk of incidence of cancer in the clinic. Therefore, the early identification and elimination of compounds showing these liabilities is important to facilitate the effectiveness and reduce the safety attritions during drug development.
We developed and validated an in vitro assay for the assessment of drug induced gastrointestinal toxicity risk using intestinal organoids. In this study we show that the in vitro mini-gut rat findings can be translated to the human mini-gut model and therefore can be used to run screenings to evaluate the potential of drug candidates to inhibit Notch in vivo.