Betaine transport in kidney and liver: use of betaine in liver injury

Cell Physiol Biochem. 2013;32(7):32-40. doi: 10.1159/000356622. Epub 2013 Dec 18.

Abstract

Betaine, also known as trimethylglycine, is an important human nutrient obtained from a variety of foods and also can be synthesized from choline. Betaine is much more abundant in kidney and liver compared to other mammalian organs. The principal role of betaine in the kidney is osmoprotection in cells of the medulla and it enters these cells via the betaine/γ-aminobutyric acid (GABA) transporter protein (BGT1), which is upregulated by hyperosmotic stress. This process has been studied in great detail. In liver, the main role of betaine is a methyl donor in the methionine cycle. However, recent studies showed that BGT1 is much more abundant in liver compared to kidney medulla. Despite this, the role of BGT1 in liver has received little attention. Entry of betaine into liver cells is a necessary first step for its action at the cellular level. Increased interest in betaine has developed because of a number of therapeutic uses. These include treatment of nonalcoholic fatty liver and hyperhomocysteinemia, a risk factor for atherosclerotic disease. Several important questions need to be addressed to better understand the potential of betaine as a therapeutic agent for other liver diseases, such as alcohol-induced injury. Heavy alcohol consumption is the most common cause for liver-related deaths and altered liver metabolism may contribute to hepatic, vascular, coronary, and cerebral diseases.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Alcohol Drinking / drug therapy
  • Alcohol Drinking / metabolism
  • Alcohol Drinking / pathology
  • Betaine / metabolism*
  • Betaine / therapeutic use
  • Biological Transport
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism
  • GABA Plasma Membrane Transport Proteins / metabolism*
  • Hepatocytes / metabolism
  • Humans
  • Kidney / drug effects*
  • Kidney / metabolism
  • Kidney Medulla / drug effects
  • Kidney Medulla / metabolism
  • Liver / drug effects*
  • Liver / injuries
  • Liver / metabolism

Substances

  • Carrier Proteins
  • GABA Plasma Membrane Transport Proteins
  • betaine plasma membrane transport proteins
  • Betaine