Understanding disruption of the gut barrier during inflammation: Should we abandon traditional epithelial cell lines and switch to intestinal organoids?

Abstract

Disruption of the intestinal epithelial barrier is a hallmark of mucosal inflammation. It increases exposure of the immune system to luminal microbes, triggering a perpetuating inflammatory response. For several decades, the inflammatory stimuli-induced breakdown of the human gut barrier was studied in vitro by using colon cancer derived epithelial cell lines. While providing a wealth of important data, these cell lines do not completely mimic the morphology and function of normal human intestinal epithelial cells (IEC) due to cancer-related chromosomal abnormalities and oncogenic mutations. The development of human intestinal organoids provided a physiologically-relevant experimental platform to study homeostatic regulation and disease-dependent dysfunctions of the intestinal epithelial barrier. There is need to align and integrate the emerging data obtained with intestinal organoids and classical studies that utilized colon cancer cell lines. This review discusses the utilization of human intestinal organoids to dissect the roles and mechanisms of gut barrier disruption during mucosal inflammation. We summarize available data generated with two major types of organoids derived from either intestinal crypts or induced pluripotent stem cells and compare them to the results of earlier studies with conventional cell lines. We identify research areas where the complementary use of colon cancer-derived cell lines and organoids advance our understanding of epithelial barrier dysfunctions in the inflamed gut and identify unique questions that could be addressed only by using the intestinal organoid platforms.

Human intestinal organoids: Modeling gastrointestinal physiology and immunopathology — current applications and limitations

“…The intestinal epithelium functions as a critical physical barrier, regulating absorption, and preventing harmful substances from entering the body. A disrupted barrier is a distinct feature of mucosal inflammation, and a characteristic of GI inflammatory diseases such as coeliac disease and IBD [3,14,44,53]. The implications of a compromised barrier in vivo include increased paracellular diffusion, and potential exposure of immune cells to luminal content, including microbiota, initiating a perpetuating inflammatory response [14].…”

“…A disrupted barrier is a distinct feature of mucosal inflammation, and a characteristic of GI inflammatory diseases such as coeliac disease and IBD [3,14,44,53]. The implications of a compromised barrier in vivo include increased paracellular diffusion, and potential exposure of immune cells to luminal content, including microbiota, initiating a perpetuating inflammatory response [14]. Our understanding of factors affecting barrier function has advanced considerably with the use of organoids [13,54].…”

Recent Advances in Cell‐Based In Vitro Models to Recreate Human Intestinal Inflammation

“…Organoids are multicellular 3D structures that can recapitulate the complex cellular organization found in vivo, overcoming reductionist in vitro models. [195] Intestinal organoids or "miniguts", as often called, emerged in the last decade as a promising alternative to model inflammatory scenarios and to explore the role of the epithelium and its surrounding environment upon mucosal injury. [167,[196][197][198] Organoids are frequently derived from adult stem cells, isolated from the small intestine or the colonic epithelium, giving rise to sophisticated constructs termed enteroids or colonoids, respectively.…”

Neonatal enteroids absorb extracellular vesicles from human milk‐fed infant digestive fluid

“…Enteroids are 3D organoid cultures grown from intestinal stem cells (Mahe et al, 2013;Sato et al, 2009). In contrast to immortalized cell lines used in previous studies (Kahn et al, 2018;Liao et al, 2017), primary neonatal enteroids are arguably a more physiologically relevant model for studying normal IEC function (Lechuga et al, 2023) as they are derived from normal infant intestinal stem cells and develop multiple differentiated IEC types.…”