Vitamin A Crucial In Role In Human Body

Vitamin A Plays Major Roles In the Human Body Crucial For Key Physiological Functions Including: Sperm Cell Formation and theDevelopment of the Central Nervous System. In a recently-published study mapping the structure and function of the "orphan" nuclear receptor TR4, Van Andel Research Institute (VARI) investigators suggest that Vitamin A may play a more direct role than was previously known in certain physiological functions including sperm cell formation and the development of the central nervous system. Scientists had previously determined that Vitamin A derivatives such as retinal and the retinoic acids are involved in physiological functions in the human body. But there has been little direct evidence to show that Vitamin A, or retinol, the most common dietary form of the vitamin and the retinoid group, is directly involved in nuclear receptor signaling pathways, a key process which activates genes in the human body. "Our study found that Vitamin A itself is active for activating nuclear receptor TR4," said VARI Researchers "Because TR4 plays roles in sperm cell production, lipid and lipoprotein regulation, the development of the central nervous system, and the regulation of hemoglobin production in the embryo, we now believe that Vitamin A may play more important roles in human physiology than was previously believed." The study, published in the Journal of Biological Chemistry, is in the top 1 percent of published papers in terms of significance and overall importance. About 50 to 100 such studies are selected from the more than 6,600 published by the journal each year. Nuclear receptors activate genes in important biological processes in the human body. Orphan nuclearreceptors are a group of nuclear receptors whose ligands, or the substance to which receptors bind, have not yet been identified, and whose physiological functions have not been very well investigated. "Recent evidence has shown that orphan nuclear receptors are required for many essential physiological functions in the human body, and can be used to help discover drug targets for human diseases," explained the research scientists. "Additionally, the identification of ligands for nuclear receptors usually leads to the discovery of new types of therapeutic drugs for human diseases. A very successful example is PPARs (peroxisome proliferator- activated receptors), whose ligands are used for the treatment of diabetes." the research team in VARI's Laboratory of Structural Sciences, under the direction of VARI Center for Structural Biology and Drug Discovery used X-ray crystallography to determine the structure of TR4's ligand binding domain. They also identified small molecules involved in TR4 transcription, the synthesis of RNA using DNA as the blueprint, that could serve as potential drug targets. Story Source: Van Andel Research Institute. Journal Reference: The Orphan Nuclear Receptor TR4 Is a Vitamin A-activated Nuclear Receptor. Journal of Biological Chemistry, 2010; A recent study from Solae backs up these claims for soy protein's cholesterol lowering effect, but says the mechanism behind benefits is 'yet to be determined'. The study published in the Journal of Clinical Lipidology, suggests that soy protein lowers total cholesterol and non-HDL cholesterol, in patients with moderately high cholesterol levels, but said that a mechanism for such benefits could not be determined. Editor's Note: This article is not intended to provide medical advice, diagnosis or treatment.