The zebrafish as a model to study intestinal inflammation

Abstract

Starting out as a model for developmental biology, during the last decade, zebrafish have also gained the attention of the immunologists and oncologists. Due to its small size, high fecundity and full annotation of its genome, the zebrafish is an attractive model system. The fact that fish are transparent early in life combined with the growing list of immune cell reporter fish, enables in vivo tracking of immune responses in a complete organism. Since zebrafish develop ex utero from a fertilized egg, immune development can be monitored from the start of life. Given that several gut functions and immune genes are conserved between zebrafish and mammals, the zebrafish is an interesting model organism to investigate fundamental processes underlying intestinal inflammation and injury. This review will first provide some background on zebrafish intestinal development, bacterial colonization and immunity, showing the similarities and differences compared to mammals. This will be followed by an overview of the existing models for intestinal disease, and concluded by future perspectives in light of the newest technologies and insights.

Comparison of Two Chemically-Induced Colitis-Models in Adult Zebrafish, Using Optical Projection Tomography and Novel Transcriptional Markers

“…Cxcl8 is pivotal in orchestrating neutrophil influx to the site of inflammation, and gene trancripts have been detected from intestinal cells in larval zebrafish in a TNBS-model [8]. As noted by Brugman [22], mice do not possess a Cxcl8 gene that is homologous to its human counterpart CXCL8, in contrast to zebrafish. This may further support the use of zebrafish IBD-model when studying neutrophil migration.…”

“…Goblet cells are an important intestinal cell type that is routinely evaluated in IBD-assessment. In human patients, depletion is seen in UC whereas a differentiation of cells often, but not always, is observed in CD, features which can be reproduced in both rodent and zebrafish models [13] [21] [22]. We have evaluated the goblet cell population in the scales and intestine of our two colitis models in order to assess whether a systemic factor is affecting goblet cell function.…”

Nematode infection in liver of the fish Gymnotus inaequilabiatus (Gymnotiformes: Gymnotidae) from the Pantanal Region in Brazil: pathobiology and inflammatory response

“…It is reasonable to concur with the statement of Secombes & Chappell [39] and Franke et al [40] that the successful infection of helminths largely depends on their capacity to evade and/or manipulate the generally efficient immune system of hosts. In recent years there has been a renaissance in the study of fish immune responses [27, 41–43], which significantly expanded our knowledge of the evolution and diversification of the vertebrate immune system [44, 45]. Innate immunity in teleosts relies on a range of cell types [46].…”

“…was observed in numerous granulomas. MCs play an important role in responding to inflammation [41] and their numbers increase as a consequence of helminth infection in fish intestine [20, 27, 55] as well as in parasitized liver [13, 22, 56]. Numerous MCs were noticed to be in close contact with capillaries and the outer layer of the endothelia as well as within the lumen of the blood vessels in an infected organ [27, 57, 58].…”

Critical Role for a Subset of Intestinal Macrophages in Shaping Gut Microbiota in Adult Zebrafish

“…To address this question, we processed intact adult zebrafish for paraffin sectioning for histological analyses and used H&E to assess overall morphology and Alcian blue and periodic acid Schiff (AB-PAS) to identify acidic and neutral mucin-containing goblet cells (Figures 4E and 4F). Furthermore, we quantified several established metrics for assessing adult intestinal structure (Brugman, 2016; Brugman et al, 2009), including intestinal wall thickness, villus fold height, and goblet cell frequency from both the proximal (S1–S4) and distal (S5–S7) regions (Wang et al, 2010; Figure S5). The intestinal epithelial protrusions in adult zebrafish, although finger-like in some regions, have also been described as being broader and irregularly patterned than the mammalian counterparts.…”