Sugar utilization by microglia in Alzheimer's disease

J Neuroimmunol. 2025 Apr 15:401:578552. doi: 10.1016/j.jneuroim.2025.578552. Epub 2025 Feb 14.

Abstract

Diabetes is a major risk factor for Alzheimer's disease (AD), yet the effect of specific carbohydrate sources in the diet on AD pathology remains unclear. The primary neuroimmune cell, microglia, undergo a metabolic shift during neuroinflammation associated with AD pathology. We utilized existing gene expression data and identified changes in sugar transporters (increased Slc2a1 (glucose) and decreased Slc2a5 (fructose) expression). To examine gene expression with respect to primary sugar source, N9 cells, a mouse microglia cell line, were cultured in glucose or fructose supplemented media and stimulated with lipopolysaccharide (LPS). RNA-sequencing analyses indicated significant changes between control and sugar supplemented media and several differentially expressed genes between glucose and fructose media. Concurrently, 5XFAD mice received equicaloric diets with specific carbohydrate sources: dextrose or fructose. Regardless of diet, sex, or genotype, all mice developed high blood sugar levels; confocal microscopy analyses indicated similar amyloid plaque burden and microglial response relative to the control diet, but there was a change in the microglial response between dextrose and fructose fed mice. Overall, these data indicate microglia preferentially express sugar transporters and sugar source may influence microglial reactivity in response to plaque pathology.

Keywords: Alzheimer's disease; Fructose; Glucose; Microglia; Sugar metabolism.

MeSH terms

  • Alzheimer Disease* / genetics
  • Alzheimer Disease* / metabolism
  • Alzheimer Disease* / pathology
  • Animals
  • Cell Line
  • Female
  • Fructose* / metabolism
  • Glucose* / metabolism
  • Humans
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Microglia* / metabolism

Substances

  • Glucose
  • Fructose