Eicosapentaenoic Acid Enhances Heat Stress-Impaired Intestinal Epithelial Barrier Function in Caco-2 Cells

Abstract

ObjectiveDysfunction of the intestinal epithelial tight junction (TJ) barrier is known to have an important etiologic role in the pathophysiology of heat stroke. N-3 polyunsaturated fatty acids (PUFAs), including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), play a role in maintaining and protecting the TJ structure and function. This study is aimed at investigating whether n-3 PUFAs could alleviate heat stress-induced dysfunction of intestinal tight junction.MethodsHuman intestinal epithelial Caco-2 cells were pre-incubated with EPA, DHA or arachidonic acid (AA) and then exposed to heat stress. Transepithelial electrical resistance (TEER) and Horseradish Peroxidase (HRP) permeability were measured to analyze barrier integrity. Levels of TJ proteins, including occludin, ZO-1 and claudin-2, were analyzed by Western blot and localized by immunofluorescence microscopy. Messenger RNA levels were determined by quantitative real time polymerase chain reaction (Q-PCR). TJ morphology was observed by transmission electron microscopy.ResultsEPA effectively attenuated the decrease in TEER and impairment of intestinal permeability in HRP flux induced by heat exposure. EPA significantly elevated the expression of occludin and ZO-1, while DHA was less effective and AA was not at all effective. The distortion and redistribution of TJ proteins, and disruption of morphology were also effectively prevented by pretreatment with EPA.ConclusionThis study indicates for the first time that EPA is more potent than DHA in protecting against heat-induced permeability dysfunction and epithelial barrier damage of tight junction.

Influence of supplementing diet with microalgae (Schizochytrium limacinum)on growth and metabolism in lambs during the summer

“…Gut flora, an important index of gastrointestinal health status, was found to be improved in weaned piglets given brown algae (6). Further, omega 3 PUFAs were found to be protective in the intestinal mucosal barrier of tight junction in heat-stressed rats (35). The numerical decrease in DAO in plasma indicates that microalgae supplementation may protect the intestinal mucosa from severe injury under heat stress.…”

Galacto-oligosaccharides exert a protective effect against heat stress in a Caco-2 cell model

“…Previous studies indicated that the heat-induced increase in paracellular permeability is mainly associated with TJ proteins assembly (Dokladny et al, 2006(Dokladny et al, , 2008. Xiao et al (2013) described that the occludin and ZO-1 mRNA and protein levels were decreased in Caco-2 cells exposed to severe thermalstress for 1 h (43°C) and n-3 polyunsaturated fatty acids protected this heat-induced permeability dysfunction.…”

“…Heat-induced multi-organ injury may include varying degrees of central nervous system dysfunction, acute renal failure, liver failure, skeletal muscle injury and gut ischaemia (Leon & Helwig, 2010). An important early symptom of thermal stress is a dysfunction of the intestinal barrier leading to increased intestinal permeability and as a consequence increased entrance of toxic luminal substances (Dokladny, Moseley, & Ma, 2006;Xiao et al, 2013). With the prospect of increasing global warming and increase in frequency and intensity of heat stress (Bouchama & Knochel, 2002), it is important to investigate preventive measures that can alleviate adverse effects of exposure to high environmental temperatures.…”

Local country food sources of methylmercury, selenium and omega-3 fatty acids in Nunavik, Northern Quebec

“…Long-chain n −3 PUFA might also contribute to mitigate intestinal MeHg absorption (Xiao et al, 2013). Analytical and in vitro studies are on-going to elucidate the different chemical forms and bioavailability of Se and Hg in Nunavik country foods, as well as the influence of country food nutrients on Hg intestinal absorption.…”