Role of Serotonin in the Maintenance of Inflammatory State in Crohn’s Disease

Abstract

Crohn’s disease (CD) is a chronic intestinal inflammation considered to be a major entity of inflammatory bowel diseases (IBDs), affecting different segments of the whole gastrointestinal tract. Peripheral serotonin (5-HT), a bioactive amine predominantly produced by gut enterochromaffin cells (ECs), is crucial in gastrointestinal functions, including motility, sensitivity, secretion, and the inflammatory response. These actions are mediated by a large family of serotonin receptors and specialized serotonin transporter (SERT) located on a variety of cell types in the gut. Several studies indicate that intestinal 5-HT signaling is altered in patients with inflammatory bowel disease. Paraformaldehyde-fixed intestinal tissues, obtained from fifteen patients with Crohn’s disease were analyzed by immunostaining for serotonin, Langerin/CD207, and alpha-Smooth Muscle Actin (α-SMA). As controls, unaffected (normal) intestinal specimens of seven individuals were investigated. This study aimed to show the expression of serotonin in dendritic cells (DCs) and myofibroblast which have been characterized with Langerin/CD207 and α-SMA, respectively; furthermore, for the first time, we have found the presence of serotonin in goblet cells. Our results show the correlation between different types of intestinal cells in the maintenance of the inflammatory state in CD linked to the recall of myofibroblasts.

Confocal Characterization of Intestinal Dendritic Cells from Myxines to Teleosts

“…Serial sections were deparaffinized and rehydrated numerous times in PBS before being blocked in 2.5% bovine serum albumin (BSA) for 1 h. Sections were then treated with primary antibodies anti-Langerin/CD2017, anti-MHC II, and anti-TLR-2, in a humidified chamber, overnight, at 4 °C, and then utilized individually and in double-label experiments [ 28 , 29 ]. Secondary antisera were Alexa Fluor 594 donkey anti-rabbit IgG TRITC conjugated and Alexa Fluor 488 donkey anti-mouse IgG FITC conjugated (Molecular Probes, Invitrogen, Eugene, OR, USA, 1:300) [ 30 , 31 ]. The sections were mounted with Vectashield (Vector Labs, Burlingame, CA, USA) to prevent photobleaching, and the cover slipped after washing [ 32 ].…”

An evaluation of the rat intestinal monoamine biogeography days following exposure to acute stress

“…For example, a stress-related augmentation of 5-HT concentrations along with the reduced turnover unique to the distal colon are consistent with a particularly prolonged exposure to heightened 5HT that could underlie the severity of pathology reported in this region. Indeed, chronic inflammation and ulcers are reported specifically within this region of people suffering from stress-related FDIGs ( Alvarado and Ciorba, 2020 ; Pergolizzi et al, 2022 ). Taken together, these results suggest that nuances across intestinal sub-areas may exist in monoaminergic responses even days following exposure to a stressor of sufficient intensity.…”

Histological and Chemical Analysis of Heavy Metals in Kidney and Gills of Boops boops: Melanomacrophages Centers and Rodlet Cells as Environmental Biomarkers

“…Kidney and gill samples were fixed in 4% paraformaldehyde in 0.1 M phosphate-buffered saline (pH 7.4) for 12–18 h, then dehydrated in graded ethanol, cleared in xylene, and embedded in Paraplast ® (McCormick Scientific LLC, St. Louis, MO, USA). Finally, serial slices (3–5 m thick) were created using a rotary microtome (LEICA 2065 Supercut, Poway, CA, USA) [ 49 , 50 , 51 , 52 ].…”