title: High-Fat Diet-Induced Retinal Dysfunction.
abstract: OBJECTIVE
  The purpose of this study was to investigate the impact of obesity-induced prediabetes/early diabetes on the retina to provide new evidence on the pathogenesis of type 2 diabetes-associated diabetic retinopathy (DR).
  
  
  METHODS
  A high-fat diet (HFD)-induced obesity mouse model (male C57BL/6J) was used in this study. At the end of the 12-week HFD feeding regimen, mice were evaluated for glucose and insulin tolerance, and retinal light responses were recorded by electroretinogram (ERG). Western immunoblot and immunohistochemical staining were used to determine changes in elements regulating calcium homeostasis between HFD and control retinas, as well as unstained human retinal sections from DR patients and age-appropriate controls.
  
  
  RESULTS
  Compared to the control, the scotopic and photopic ERGs from HFD mice were decreased. There were significant decreases in molecules related to cell signaling, calcium homeostasis, and glucose metabolism from HFD retinas, including phosphorylated protein kinase B (pAKT), glucose transporter 4, L-type voltage-gated calcium channel (L-VGCC), and plasma membrane calcium ATPase (PMCA). Similar changes for pAKT, PMCA, and L-VGCC were also observed in human retinal sections from DR patients.
  
  
  CONCLUSIONS
  Obesity-induced hyperglycemic and prediabetic/early diabetic conditions caused detrimental impacts on retinal light sensitivities and health. The decrease of the ERG components in early diabetes reflects the decreased neuronal activity of retinal light responses, which may be caused by a decrease in neuronal calcium signaling. Since PI3K-AKT is important in regulating calcium homeostasis and neural survival, maintaining proper PI3K-AKT signaling in early diabetes or at the prediabetic stage might be a new strategy for DR prevention.
authors: Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, United States.
authors: Richard Cheng-An
authors: RC
authors: Chang
authors: Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, United States.
authors: Liheng
authors: L
authors: Shi
authors: Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, United States.
authors: Cathy Chia-Yu
authors: CC
authors: Huang
authors: Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, United States.
authors: Andy Jeesu
authors: AJ
authors: Kim
authors: Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, United States.
authors: Michael L
authors: ML
authors: Ko
authors: Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, United States.
authors: Beiyan
authors: B
authors: Zhou
authors: Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, United States 3Texas A&M Institute of Neuroscience, Texas A&M University, College Station, Texas, Unite.
authors: Gladys Y-P
authors: GY
authors: Ko
mesh_terms: D000818:Animals; D015153:Blotting, Western; D020746:Calcium Channels, L-Type / Q000378:metabolism; D059305:Diet, High-Fat / Q000009:adverse effects*; D004596:Electroretinography; D051275:Glucose Transporter Type 4 / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D053499:Plasma Membrane Calcium-Transporting ATPases / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D012164:Retinal Diseases / Q000175:diagnosis / Q000209:etiology* / Q000378:metabolism
chemical_list: D020746:Calcium Channels, L-Type; D051275:Glucose Transporter Type 4; D051057:Proto-Oncogene Proteins c-akt; D053499:Plasma Membrane Calcium-Transporting ATPases