Differential Transcriptomic Profiles in Canine Intestinal Organoids Following Lipopolysaccharide Stimulation

Abstract

Lipopolysaccharide (LPS) is associated with chronic intestinal inflammation and promotes intestinal cancer progression in the gut. While the interplay between LPS and intestinal immune cells has been well characterized, little is known about LPS and intestinal epithelium interactions. In this study, we explored the differential effect of LPS on proliferation and the transcriptome in 3D enteroids/colonoids obtained from dogs with naturally occurring gastrointestinal (GI) diseases, such as Inflammatory Bowel Disease (IBD) and GI mast cell tumor. The study objective was to analyze LPS-induced modulation of signaling pathways involving the intestinal epithelia and critical to colorectal cancer development in the context of IBD or a tumor microenvironment. While LPS incubation resulted in a pro-cancer gene expression pattern and stimulated proliferation of IBD enteroids and colonoids, down-regulation of several cancer-associated genes like CRYZL1, Gpatch4, SLC7A1, ATP13A2, and ZNF358 was also observed in tumor enteroids. Genes participating in porphyrin metabolism (CP), thiamine and purine metabolism (TAP2, EEF1A1), arachidonic acid, and glutathione metabolism (GPX1) exhibited a similar pattern of altered expression between IBD enteroids and IBD colonoids following LPS stimulation. In contrast, genes involved in anion transport, transcription and translation, apoptotic processes, and regulation of adaptive immune responses showed opposite expression patterns between IBD enteroids and colonoids following LPS treatment. In brief, the cross-talk between LPS/TLR4 signal transduction pathway and several metabolic pathways, such as fatty acid degradation and biosynthesis, and purine, thiamine, arachidonic acid, and glutathione metabolism, may be important in driving chronic intestinal inflammation and intestinal carcinogenesis.

Oxidative stress, hormones, and effects of natural antioxidants on intestinal inflammation in inflammatory bowel disease

“…Antioxidants that can regenerate their original qualities through interactions with other antioxidants are referred to as an "antioxidant network" (41). Growing research suggests that pathological states characterized by elevated ROS levels are associated with diminished enzymatic and non-enzymatic antioxidant activity (34,39,(42)(43)(44)(45)(46)(47)(48)(49)(50)(51)(52)(53)(54)(55)(56)(57)(58)(59). The signaling pathways of nuclear factor kappa B (NF-kB), mitogen-activated protein kinase (MAPK), and signal transducer and activator of transcription 3 (STAT3) are among the major targets that can be influenced by ROS.…”

“…Modulation of the stress response genes, including the antioxidant enzyme GPX1, was detected after LPS stimulation of the IBD enteroids and colonoids (57). Organoids have more advantages than conventional models and have been employed in fundamental and clinical research, such as for genetic and infectious diseases, regenerative medicine, and accurate and reliable drug screening (162)(163)(164)(165)(166)(167)(168).…”

“…Nutritional and pharmacological dosages of proanthocyanidins protect against endotoxin (LPS)-induced intestinal inflammation, OS, and intestinal permeability in colitic rats (197). Notably, areaspecific LPS-induced inflammation in the intestine has been identified, and a unique gene signature may be useful to determine the affected intestinal region (57). Treatment with GSPE reduces MPO and COX-2 activity, modifies the gene expression of ileal inflammatory and permeability proteins, and reduces ROS, MDA, and NO levels, and iNOS activities (Supplementary Table 1) in the large intestine (109,197).…”