The Mechanism of Lipopolysaccharide Escaping the Intestinal Barrier in Megalobrama amblycephala Fed a High-Fat Diet

Abstract

With the popularity of western food characterized by excessive fat and sugars, obesity has currently been a public health issue. Low-grade chronic inflammation accompanied by obesity increases the risk of multiple epidemics such as diabetes, cancer and cardiovascular diseases. Here, we show that feeding Megalobrama amblycephala with a high-fat diet (HFD) drives obesity-related chronic inflammation and the penetration of lipopolysaccharide (LPS). Interference with antibiotics inhibits the produce of LPS and this alleviates the sustained release of pro-inflammatory factors induced by HFD. LPS penetration is attributed to weakened intestinal mucus barrier after high-fat exposure. Mechanically, the consumption of HFD inhibits the secretion of mucin 2 (MUC2) due to the induction of endoplasmic reticulum stress mediated by the inositol-requiring enzyme 1 (IRE1) /X box-binding protein 1 (XBP1) pathway in goblet cells. Furthermore, excessive lipid exacerbates the leakage of LPS across the intestinal epithelial cell barrier via the transcellular pathway. Mechanically, lipid increases the internalization of LPS in intestinal epithelial cells depending on the activation of fatty acid translocase (FAT/CD36). These results demonstrate that HFD causes the penetration of LPS due to the weakened intestinal mucosal barrier and the assistance of CD36.

Polygonum tinctorium leaf extract ameliorates high-fat diet-induced intestinal epithelial damage in mice

“…In addition, the level of sXBP-1 mRNA in HFD-fed mice was similar to that in the NC-fed mice. According to previous reports, ER stress occurs at least 11 weeks after HFD consumption (17,20). Our results indicated that indigo Ex exerts a protective effect independently of intestinal inflammation or ER stress.…”

“…2A ). Dietary fat-induced endoplasmic reticulum (ER) stress is associated with impaired goblet cell function and mucin depletion ( 17 , 20 ). Therefore, we evaluated the mRNA levels of sXBP-1, an unfolded protein response (UPR) signaling molecule.…”

The Prebiotic Effects of an Extract with Antioxidant Properties from Morus alba L. Contribute to Ameliorate High-Fat Diet-Induced Obesity in Mice

“…As previously described, another accepted hypothesis to explain the systemic inflammatory state linked to a fat diet lies in the translocation of bacterial components such as LPS that causes metabolic endotoxemia [ 56 ]. LPS leakage is associated with gut dysbiosis and an impairment of the gut barrier integrity after high-fat exposure [ 56 , 57 ]. Moreover, gut dysbiosis associated with obesity results in the release of LPS by Gram-negative bacteria that diffuses through the altered tight junctions or is incorporated into chylomicrons [ 58 ].…”

Tea Tree Oil Mediates Antioxidant Factors Relish and Nrf2-Autophagy Axis Regulating the Lipid Metabolism of Macrobrachium rosenbergii

“…We performed Western blot analysis with reference to Dai et al [ 37 ]. Simply put, the protein was extracted from hepatopancreas tissue with a high-fat protein extraction kit (BB3162, Bestbio Biotechnology Co., LTD., Shanghai, China) and we performed Western blot by the manufacturer’s guidelines (Bio/Rad, Hercules, CA, USA).…”