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.

Background: Chemoresistance remains a major obstacle to the treatment of esophageal cancer patients. Exosome-mediated transfer of circular RNAs (circRNAs) has been reported to be related to drug resistance in esophageal cancer. This study is designed to explore the role and mechanism of exosomal circ_0000337 on CDDP resistance in esophageal cancer.Methods: Cell viability, proliferation, colony number, apoptosis, migration, and invasion were assessed by Cell Counting Kit-8 (CCK-8), colony formation, flow cytometry, and transwell assays. Circ_0000337, microRNA-377 (miR-377-3p), and Janus kinase 2 (JAK2) levels were detected by real-time quantitative polymerase chain reaction (RT-qPCR). Exosomes were isolated and detected by differential centrifugation and a transmission electron microscope. Protein levels of CD9, CD63, and JAK2 were tested by Western blot assay. The binding relationship between miR-377-3p and circ_0000337 or JAK2 was predicted by circinteractome or Starbase and then verified by dual-luciferase reporter assay and RNA pull-down assay. The biological role of exosomal circ_0000337 and CDDP on esophageal cancer cell growth was examined by the xenograft tumor model in vivo.Results: Circ_0000337 and JAK2 were highly expressed, and miR-377-3p was decreased in CDDP-resistant esophageal cancer tissues and cells. Moreover, circ_0000337-containing exosomes secreted by CDDP-resistant esophageal cancer cells could promote CDDP resistance, cell growth, and metastasis in CDDP-sensitive esophageal cancer cells in vitro. The mechanical analysis discovered that circ_0000337 functioned as a sponge of miR-377-3p to regulate JAK2 expression. Exosomal circ_0000337 increased the drug resistance of esophageal cancer in vivo.Conclusion: Exosomal circ_0000337 accelerated CDDP resistance of esophageal cancer cells partly by regulating the miR-377-3p/JAK2 axis, hinting a promising therapeutic target for the esophageal cancer treatment.

BackgroundSepsis is now the leading cause of death in the non-cardiovascular intensive care unit (ICU). Recent research suggests that sepsis is likely to be due to an interaction between genetic and environmental factors. Genetic mutations of toll-like receptor 4 (TLR4) and cluster of differentiation 14 (CD14) genes are involved in the immune and (or) inflammatory response. These may contribute to the susceptibility to sepsis in patients. This study was designed to evaluate whether the TLR4 and cluster CD14 gene polymorphisms are associated with susceptibility to sepsis.MethodsThe single nucleotide polymorphisms (SNPs) of TLR4 (rs10759932, rs11536889, rs7873784, rs12377632, rs1927907, rs1153879) and CD14 (rs2569190 and rs2563298) in patients with sepsis and control subjects in the Guangxi Province were analyzed by using the polymerase chain reaction-single base extension (PCR-SBE) and DNA sequencing methods.ResultsThe rs11536889 polymorphism in TLR4 and rs2563298 polymorphism in CD14 were significantly associated with the risk of sepsis when compared to the control group. The frequencies of rs11536889 and rs2563298 polymorphisms in the group with sepsis were higher than that in the control group (OR = 1.430, 95% CI, 1.032-1.981, P<0.05; OR = 2.454, 95% CI, 1.458-4.130, P<0.05, respectively). Followed up haplotype analysis suggested that there were two haplotypes in which increased risk factors for sepsis were indicated.ConclusionsThe rs11536889 polymorphism in TLR4 and rs2563298 polymorphism in CD14, and two haplotypes were associated with increased susceptibility to sepsis.