Navigation Links
Rutgers researchers unlock mysteries of vitamin A metabolism during embryonic development
Date:2/28/2008

New Brunswick, NJResearchers at Rutgers have unlocked some of the mysteries of how the developing embryo reacts to fluctuations in the amount of vitamin A present in the maternal blood stream. Their results are presented in the February 28 issue of the Journal of Biological Chemistry.

The researchers studied the role of LRAT, a protein that facilitates the formation of vitamin A stores in the body, during embryonic development. In particular, they showed how LRAT protects developing tissues from potentially toxic levels of vitamin A that have been ingested by the mother. Although this function of LRAT had previously been hypothesized in adults, this is the first time that its role has been demonstrated during embryonic development.

The developing mammalian embryo is entirely dependent on the maternal circulation for its supply of retinoids, the vitamin A metabolites produced in the body. These are essential nutrients and they control the formation of the embryos heart, central nervous system, eyes and other important organs and tissues. Malformations of the developing embryo can occur when too little, or too much, vitamin A is consumed by the mother.

We were looking for the mechanisms that allow the fetus to maintain adequate amount of retinoids, whether the mother has over- or under-consumed vitamin A, said Dr. Loredana Quadro, an assistant professor in the Department of Food Science and member of the Center for Lipid Research at the Rutgers School of Environmental and Biological Sciences. We also looked at the effects of different levels of vitamin A being transferred from the mother to the fetus.

When vitamin A is ingested, it is converted into retinyl ester (RE) in the intestine from where it is secreted in the bloodstream packaged with other dietary lipids into lipoprotein particles called chylomicrons. The majority of dietary RE reaches the liver, the main body storage site of vitamin A. Under insufficient dietary vitamin A intake, the liver transforms RE into retinol (ROH), which is then secreted into the bloodstream bound to retinol-binding protein (RBP), its sole specific serum carrier, to be delivered to the target tissues. Upon intake through a specific membrane receptor named Stra6, ROH is ultimately converted to retinoic acid (RA), which is the active form of vitamin A. If tissue RA is in excess, it is transformed into inactive forms, such as 4-hydroxy retinoic acid or 4-oxo retinoic acid (OXO-RA) by the action of a specific enzyme named Cyp26A1.

When we think about vitamin A, we think about one compound, said Quadro. But in reality, the term vitamin A comprises a family of different compounds. Each one has a slightly different action, and plays a different role.

The Rutgers researchers took a closer look at how ROH is metabolized into RE and RA to maintain an optimal balance of retinoids during the formation of the embryo. Mutant mice lacking both RBP and LRAT were generated to perform this study, so as to interfere with the two main pathways of maternal vitamin A delivery to the fetus (ROH-RBP from the liver stores and RE of dietary origin).

We hypothesized that the lack of ROH-RBP and LRAT would make the embryo more vulnerable to changes in maternal dietary vitamin A intake, said Quadro and our data proved this to be correct. Indeed, a severe embryonic vitamin A deficiency is readily attainable when the mothers are deprived of dietary vitamin A during pregnancy. Therefore, this strain turned out to be a very good model to study how embryonic development is affected by fluctuations in the amount of retinoids present in the maternal diet and hence in the maternal circulation.

The researchers identified LRAT, Cyp26A1 and Stra6 as the three key molecular players that act in coordination to protect the developing tissues from potentially detrimental levels of vitamin A ingested by the mother. "Understanding vitamin A metabolism in the developing fetus could have broad implications," said Quadro. "Consumption of large doses of dietary supplements and vitamins, including vitamin A, has become a very common practice in recent years, generating the necessity to investigate the effects of high doses of vitamin A intake at different stages of the lifecycle, including pregnancy and development. These studies expand our knowledge of maternal-fetal nutrition and dietary contribution to embryonic development and may ultimately provide new insight into appropriate dietary practices during pregnancy."


'/>"/>

Contact: Michele Hujber
hujber@aesop.rutgers.edu
732-932-7000
Rutgers University
Source:Eurekalert  

Related medicine news :

1. Rutgers College of Nursing faculty member Rachel Jones wins New York Times Nurse Award
2. Rutgers biomaterial debuts in clinical trials of new stent
3. N.J. nurses are overworked according to Rutgers College of Nursing professor
4. Rutgers College of Nursing emerita professor Beverly Whipple receives FSSS book award
5. Rutgers College of Nursing faculty member Rachel Jones awarded Rutgers-Newark Provost Award
6. Rutgers center sparks liquid bandage, a new frontline wound treatment
7. NJSNA honors Rutgers College of Nursings Linda Flynn for excellence in research
8. Stanford researchers find culprit in aging muscles that heal poorly
9. UCLA researchers identify markers that may predict diabetes in still-healthy people
10. Mayo Clinic researchers discover new diagnostic test for detecting infection in prosthetic joints
11. Bipolar disorder relapses halved by Melbourne researchers
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Rutgers researchers unlock mysteries of vitamin A metabolism during embryonic development
(Date:6/23/2017)... ... , ... American Farmer, will feature Chr. Hansen, Inc (CHR Hansen) in an ... 2017. American Farmer airs Tuesdays at 8:30aET on RFD-TV. Check your local listings for ... Denmark in 1874 after a groundbreaking discovery of how to industrialize enzymes. Rooted in ...
(Date:6/23/2017)... WV (PRWEB) , ... June 23, 2017 , ... ... protection services and personal financial planning to families and business owners in North ... Stones organization to help provide services to differently abled residents in the region. ...
(Date:6/22/2017)... ... 2017 , ... Groove Ring is excited to announce they've partnered with Olympic ... bands and all-purpose rings. Whether you’re an athlete, adventurer, professional, or love to venture ... , From the rock face to the auto shop, Groove Ring is the world's ...
(Date:6/22/2017)... ... June 22, 2017 , ... A June 12 article ... correspondent concerned about an apparent lack of oral hygiene by an aged parent who ... and dementia-related matters, suggests a number of steps, including scheduling a dentist visit. Northridge ...
(Date:6/20/2017)... ... June 20, 2017 , ... After months of negotiations, FaceCradle USA is proud to announce the ... June 21. , “Introducing our product on QVC is something we all worked hard to ... pillow to more than 90 million homes in the United States,” said FaceCradle USA President ...
Breaking Medicine News(10 mins):
(Date:6/5/2017)... Cincinnati location of Diplomat Specialty Infusion ... been awarded a Top Workplaces 2017 honor by ... on an employee survey administered by WorkplaceDynamics, LLC, a research ... measures several aspects of workplace culture, including alignment, execution, and ... ...
(Date:6/1/2017)... June 1, 2017 Nutriceutical Holdings (NH), parent ... Solutions (VRS), and KD Pharma Group have decided to ... by KD Pharma Group. KD Pharma Group will become ... to acquire the entire company. "We believe ... are committed to growing the NH companies by providing ...
(Date:5/29/2017)... -- Cellect Biotechnology Ltd. (NASDAQ: APOP ; TASE: APOP), ... selection of stem cells, today provided a corporate update ... March 31 st , 2017. "We ... quarter of 2017," said Dr. Shai Yarkoni, Chief Executive ... of the first blood cancer patient in the recently ...
Breaking Medicine Technology: