Glucose, Fructose, and Urate Transporters in the Choroid Plexus Epithelium

Int J Mol Sci. 2020 Sep 30;21(19):7230. doi: 10.3390/ijms21197230.

Abstract

The choroid plexus plays a central role in the regulation of the microenvironment of the central nervous system by secreting the majority of the cerebrospinal fluid and controlling its composition, despite that it only represents approximately 1% of the total brain weight. In addition to a variety of transporter and channel proteins for solutes and water, the choroid plexus epithelial cells are equipped with glucose, fructose, and urate transporters that are used as energy sources or antioxidative neuroprotective substrates. This review focuses on the recent advances in the understanding of the transporters of the SLC2A and SLC5A families (GLUT1, SGLT2, GLUT5, GLUT8, and GLUT9), as well as on the urate-transporting URAT1 and BCRP/ABCG2, which are expressed in choroid plexus epithelial cells. The glucose, fructose, and urate transporters repertoire in the choroid plexus epithelium share similar features with the renal proximal tubular epithelium, although some of these transporters exhibit inversely polarized submembrane localization. Since choroid plexus epithelial cells have high energy demands for proper functioning, a decline in the expression and function of these transporters can contribute to the process of age-associated brain impairment and pathophysiology of neurodegenerative diseases.

Keywords: BCRP/ABCG2; GLUT; SGLT; URAT1; aging; blood-cerebrospinal fluid barrier; cell polarity; metabolism; neurodegenerative diseases; renal proximal tubule.

Publication types

  • Review

MeSH terms

  • ATP Binding Cassette Transporter, Subfamily G, Member 2 / genetics*
  • Brain / metabolism
  • Choroid Plexus / growth & development
  • Choroid Plexus / metabolism*
  • Epithelial Cells / metabolism
  • Epithelium / metabolism
  • Fructose / metabolism
  • Glucose / metabolism
  • Glucose Transport Proteins, Facilitative / genetics
  • Glucose Transporter Type 1 / genetics*
  • Humans
  • Neoplasm Proteins / genetics*
  • Organic Anion Transporters / genetics*
  • Organic Cation Transport Proteins / genetics*
  • Sodium-Glucose Transporter 1 / genetics
  • Uric Acid / metabolism

Substances

  • ABCG2 protein, human
  • ATP Binding Cassette Transporter, Subfamily G, Member 2
  • Glucose Transport Proteins, Facilitative
  • Glucose Transporter Type 1
  • Neoplasm Proteins
  • Organic Anion Transporters
  • Organic Cation Transport Proteins
  • SLC22A12 protein, human
  • SLC2A1 protein, human
  • Sodium-Glucose Transporter 1
  • Uric Acid
  • Fructose
  • Glucose