title: Supplementing dietary sugar promotes endoplasmic reticulum stress-independent insulin resistance and fatty liver in goose.
abstract: It is known that endoplasmic reticulum stress (ERS) contributes to insulin resistance (IR) and non-alcoholic fatty liver disease (NAFLD) in mammals. However, we recently demonstrated that overfeeding with a traditional diet (mainly consisting of cooked maize) does not induce ERS in goose. As cellular studies show that high glucose and palmitate can trigger ERS in mammalian cells, we hypothesized that supplementing sugar to the traditional diet could induce ERS, thus promoting insulin resistance and fatty liver. To test the hypothesis, we first treated goose primary hepatocytes with high glucose (25 mM and 50 mM) and palmitate (0.5 mM) supplemented with or without 0.25 mM oleate. Data indicated that, as in mammalian cells, high glucose and palmitate indeed induced ERS in goose primary hepatocytes, and palmitate-induced ERS was suppressed by supplemental 0.25 mM oleate. We then tested the hypothesis with an in vivo study, in which Landes geese overfed with traditional or novel diets (i.e., the traditional diet supplemented with sugar) were compared with control geese (normally fed with cooked maize) for ERS, IR and fatty liver. The differences in glucose tolerance, insulin tolerance and postprandial blood glucose between the geese overfed with traditional and novel diets suggested that supplementing dietary sugar promoted IR. This promotion was accompanied with an increasing trend of liver weight and abdominal fat weight relative to body weight. Surprisingly, compared to overfeeding with the traditional diet, overfeeding with the novel diet did not induce ERS, even further suppressed ERS in goose fatty liver. Together, our findings suggest that supplementing dietary sugar promotes ERS-independent IR and fatty liver in goose. It is intriguing to discover the factor(s) protecting goose liver from ERS as well as the non-ERS mechanism underlying IR.
authors.affiliation: College of Animal Science and Technology, Yangzhou University, Yangzhou, 225009, PR China; Institute of Epigenetics and Epigenomics, Yangzhou University, Yangzhou, 225009, PR China. Electronic address: tygeng@yzu.edu.cn.
authors.forename: Tuoyu
authors.initials: T
authors.lastname: Geng
authors.affiliation: College of Animal Science and Technology, Yangzhou University, Yangzhou, 225009, PR China.
authors.forename: Xing
authors.initials: X
authors.lastname: Zhao
authors.affiliation: College of Animal Science and Technology, Yangzhou University, Yangzhou, 225009, PR China.
authors.forename: Lili
authors.initials: L
authors.lastname: Xia
authors.affiliation: College of Animal Science and Technology, Yangzhou University, Yangzhou, 225009, PR China.
authors.forename: Long
authors.initials: L
authors.lastname: Liu
authors.affiliation: College of Animal Science and Technology, Yangzhou University, Yangzhou, 225009, PR China.
authors.forename: Fuyuan
authors.initials: F
authors.lastname: Li
authors.affiliation: College of Animal Science and Technology, Yangzhou University, Yangzhou, 225009, PR China.
authors.forename: Biao
authors.initials: B
authors.lastname: Yang
authors.affiliation: College of Animal Science and Technology, Yangzhou University, Yangzhou, 225009, PR China.
authors.forename: Qianqian
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Department of Botany, University of British Columbia, 6270 University Boulevard, British Columbia, V6T 1Z4, Canada.
authors.forename: Sean
authors.initials: S
authors.lastname: Montgomery
authors.affiliation: College of Animal Science and Technology, Yangzhou University, Yangzhou, 225009, PR China; Institute of Epigenetics and Epigenomics, Yangzhou University, Yangzhou, 225009, PR China.
authors.forename: Hengmi
authors.initials: H
authors.lastname: Cui
authors.affiliation: College of Animal Science and Technology, Yangzhou University, Yangzhou, 225009, PR China. Electronic address: yzgong@163.com.
authors.forename: Daoqing
authors.initials: D
authors.lastname: Gong
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D004040:Dietary Carbohydrates / Q000008:administration & dosage* / Q000009:adverse effects; D000091342:Endoplasmic Reticulum Chaperone BiP; D059865:Endoplasmic Reticulum Stress / Q000187:drug effects* / Q000502:physiology*; D005234:Fatty Liver / Q000209:etiology* / Q000378:metabolism / Q000473:pathology; D005777:Geese; D015870:Gene Expression / Q000187:drug effects; D005947:Glucose / Q000008:administration & dosage / Q000009:adverse effects; D005951:Glucose Tolerance Test; D006360:Heat-Shock Proteins / Q000235:genetics; D022781:Hepatocytes / Q000187:drug effects / Q000378:metabolism; D007333:Insulin Resistance / Q000502:physiology*; D019301:Oleic Acid / Q000008:administration & dosage; D009929:Organ Size / Q000187:drug effects; D019308:Palmitic Acid / Q000008:administration & dosage / Q000009:adverse effects
chemical_list: D004040:Dietary Carbohydrates; D000091342:Endoplasmic Reticulum Chaperone BiP; D006360:Heat-Shock Proteins; D019301:Oleic Acid; D019308:Palmitic Acid; D005947:Glucose
keywords: Diet; Endoplasmic reticulum stress; Glucose tolerance test; Goose; Insulin resistance; Non-alcoholic fatty liver disease