Impact of chronic immobilization stress on parameters of colonic homeostasis in BALB/c mice

Abstract

The intestinal epithelium is a monolayer of cells arranged side-by-side and connected by tight junction (TJ) proteins expressed at the apical extreme of the paracellular membrane. This layer prevents stress-induced inflammatory responses, thus helping to maintain gut barrier function and gut homeostasis. The aim of the present study was to evaluate the effects of chronic immobilization stress on the colonic expression of various parameters of homeostasis. A total of two groups of female BALB/c mice (n=6) were included: A stressed group (short-term immobilization for 2 h/day for 4 consecutive days) and an unstressed (control) group. Colon samples were obtained to detect neutrophils and goblet cells by optical microscopy, TJ protein expression (occludin, and claudin −2, −4, −7, −12 and −15) by western blotting, mRNA levels of TJ genes and proinflammatory cytokines [tumor necrosis factor (TNF)-α, interleukin (IL)-1β, −6 and −8] by reverse transcription-quantitative PCR, fecal lactoferrin by ELISA and the number of colony-forming units of aerobic bacteria. Compared with goblet cells in control mice, goblet cells were enlarged and reduced in number in stressed mice, whereas neutrophil cellularity was unaltered. Stressed mice exhibited reduced mRNA expression for all evaluated TJ mRNAs, with the exception of claudin-7, which was upregulated. Protein levels of occludin and all claudins (with the exception of claudin-12) were decreased in stressed mice. Fecal lactoferrin, proinflammatory cytokine mRNA levels and aerobic bacterial counts were all increased in the stressed group. These results indicated that immobilization stress induced proinflammatory and potential remodeling effects in the colon by decreasing TJ protein expression. The present study may be a useful reference for therapies aiming to regulate the effects of stress on intestinal inflammatory dysfunction.

Differential Activation of Colonic Afferents and Dorsal Horn Neurons Underlie Stress-Induced and Comorbid Visceral Hypersensitivity in Female Rats

“…Rats were restrained in Broome style rodent restrainers (4.8 cm diameter, 20 cm length) preventing movement for 2 hours per day for 4 consecutive days 31,37,51 .…”

PDE9 Inhibitor PF-04447943 Attenuates DSS-Induced Colitis by Suppressing Oxidative Stress, Inflammation, and Regulating T-Cell Polarization

“…Thereafter, the section was incubated in 0.5% periodic acid at room temperature (RT) for 15 min, followed by washing. The section was stained with Schiff's reagent at RT for 30 min and wash with warm water (Machorru-Rojas et al, 2019). Thereafter, the section was investigated and photographed under a light microscope (Model: BX51, Olympus, Japan; camera: DP20).…”

Intestinal Homeostasis under Stress Siege

“…TEER was decreased in the jejunum of rats under subacute stress by (i) isolation/limited movement for 24 h, (ii) crowding chronic stress for 14 days, and (iii) a combination of both subacute and chronic stress [ 69 ]. Altered expression of tight junction proteins involved in the control of intestinal permeability was found in the duodenum of rats under acute WAS for 4 h [ 70 ], the jejunum of rats under subacute stress [ 69 ], the colon of rats under chronic WAS [ 71 ], and the colon of mice under repeated stress by board immobilization 2 h a day for 4 days [ 72 ]. Stress-induced corticosterone elicitation underlies alterations on tight junction protein expression and on gut permeability augment, as found in rats exposed to WAS for 4 h [ 70 ], rats under subacute, chronic, and subacute/chronic stress [ 69 ], as well as rats under chronic WAS [ 71 ].…”

“…As documented in several murine models, stress has a prominent impact on goblet cell depletion in the small intestine and the colon [ 72 , 77 , 78 ]. The presumable mechanism of stress-induced goblet cell depletion via the CRH pathway results from gene protein factors that control differentiation and maturation of goblet cells.…”

“…Moreover, stress-induced goblet cell depletion may result from apoptosis, as found in ileal epithelial cells from rats subjected to WAS for 1 h a day for 5 days; this phenomenon presumably occurs via the CRH receptor pathway [ 80 ]. The effect of stress on goblet cell enlargement, as well as on hyperplasia of enteroendocrine cells and mast cells, has been documented in several experimental stress settings in mice and rats [ 62 , 72 , 79 ]. The underlying mechanism that mediates stress-induced hyperplasia is not fully known, but it might result from stress-induced CRH receptor 1 (CRH-R1) signal, based on duodenal endocrine cells from neonatal rats that underwent maternal deprivation stress [ 79 ].…”