Navigation Links
Bloodless worm sheds light on human blood, iron deficiency
Date:4/16/2008

Using a lowly bloodless worm, University of Maryland researchers have discovered an important clue to how iron carried in human blood is absorbed and transported into the body. The finding could lead to developing new ways to reduce iron deficiency, the worlds number one nutritional disorder.

With C. elegans, a common microscopic worm that lives in dirt, Iqbal Hamza, assistant professor of animal and avian sciences, and his team identified previously unknown proteins that are key to transporting heme, the molecule that creates hemoglobin in blood and carries iron. It is a critical step in understanding how our bodies process iron. Their findings are published in the April 16 issue of Nature online.

The structure of hemoglobin has been crystallized over and over, says Hamza, but no one knows how the heme gets into the globin, or how humans absorb iron, which is mostly in the form of heme.

To understand the underlying issues of nutritional and genetic causes of iron deficiency, we are looking at the molecules and mechanisms involved in heme absorption. Once you understand transport of heme, you can more effectively deliver it to better absorb iron in the human intestine.

Heme and Blood

Heme is a critical molecule for health in all eukaryotes, organisms whose cells are organized into complex structures enclosed in membranes. Species of eukaryotes range from humans to bakers yeast. Heme makes blood red and binds to oxygen and other gases we need to survive.

Heme is created in the mitochondria, then moves through pathways that connect other cells, where it is synthesized to form blood. Heme on its own, however, is toxic.

We wanted to find out how heme gets carried between and within cells, said Hamza.

A Bloodless Worm

Eight steps are required to generate heme, making it a difficult process to control in the study of heme transport pathways, as Hamza learned when he first studied the question in bacteria and mice.

So Hamza did the non-intuitive thing. He chose a test subject that doesnt make heme, but needs it to survive, that doesnt even have blood, but shares a number of genes with humans the C. elegans roundworm, a simple nematode.

We tried to understand how blood is formed in an animal that doesnt have blood, that doesnt turn red, but has globin, Hamza said.

C. elegans gets heme by eating bacteria in the soil where it lives. C. elegans consumes heme and transports it into the intestine. So now you have a master valve to control how much heme the animal sees and digests via its food, Hamza explains.

C. elegans has several other benefits for studying heme transport. Hamzas team could control the amount of heme the worms were eating. With only one valve controlling the heme transport, the scientists knew exactly where heme was entering the worms intestine, where, as in humans, it is absorbed.

And C. elegans is transparent, so that under the microscope researchers could see the movement of the heme ingested by the worm.

Genes and Iron Deficiency

The study revealed several findings that could lead to new treatment for iron deficiency. One was the discovery that genes are involved in heme transport. Hamzas group found that HRG-1 genes, which are common to humans and C. elegans, were important regulators of heme transport in the worm.

To test their findings in an animal that makes blood, Hamzas team removed the HRG-1 gene in zebrafish. The fish developed bone and brain defects, much like birth defects. The gene removal also resulted in a severe form of anemia usually caused by iron deficiencies.

When they substituted the zebrafish gene with the worm HRG-1 gene, the mutant fish returned to normal, indicating that the fish and worm genes are interchangeable, irrespective of the animals ability to make blood.

They also found that too little or too much heme can kill C. elegans, a result that could help researchers find ways to treat people who suffer from iron deficiency caused by parasitic worms.

More than two billion people are infected with parasites, says Hamza. Hookworms eat a huge amount of hemoglobin and heme in their hosts. If we can simultaneously understand heme transport pathways in humans and worms, we can exploit heme transport genes to deliver drugs disguised as heme to selectively kill parasites but not harm the host.


'/>"/>

Contact: Ellen Ternes
eternes@umd.edu
301-405-4627
University of Maryland
Source:Eurekalert

Related biology news :

1. Journey to the center of the earth: Discovery sheds light on mantle formation
2. New radar satellite technique sheds light on ocean current dynamics
3. 480-million-year-old fossil sheds light on 150-year-old paleontological mystery
4. Research sheds light on the mechanics of gene transcription
5. Shilatifard Lab sheds light on molecular machinery required for translation of histone crosstalk
6. Massive dinosaur discovered in Antarctica sheds light on life, distribution of sauropodomorphs
7. Research sheds new light on how diseases jump across species
8. New study sheds light on Galápagos hawk evolutionary history
9. CU-Boulder worm study sheds light on human aging, inherited diseases
10. UT researcher sheds new light on hybrid animals
11. New research sheds light on Hobbit
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/10/2016)... -- --> --> ... Access Management Market by Component (Provisioning, Directory Services, Password ... Size, by Deployment, by Vertical, and by Region - ... is estimated to grow from USD 7.20 Billion in ... Compound Annual Growth Rate (CAGR) of 12.2% during the ...
(Date:3/8/2016)... 8, 2016   Valencell , the leading ... it has secured $11M in Series D financing. ... new venture fund being launched by UAE-based financial ... existing investors TDF Ventures and WSJ Joshua Fund. ... its triple-digit growth and accelerate its pioneering innovation ...
(Date:3/2/2016)... 2016 http://www.researchandmarkets.com/research/cmt3hk/global_biometrics ) ... "Global Biometrics as a Service Market 2016-2020" ... --> http://www.researchandmarkets.com/research/cmt3hk/global_biometrics ) has announced the ... a Service Market 2016-2020" report to ... and Markets ( http://www.researchandmarkets.com/research/cmt3hk/global_biometrics ) has announced ...
Breaking Biology News(10 mins):
(Date:5/3/2016)... ... May 03, 2016 , ... Leading CEOs from biotech, pharmaceutical, ... and June 1st at The Four Seasons Hotel Boston. , The Boston CEO ... offering exclusive access to key decision makers who influence deal making and investment. ...
(Date:5/3/2016)... - And Other Rising Companies ... Those Competitor Biologics  - Biosimilar Drug Producers ... ,  Who are the most important and ... their sales potentials? Discover, in our updated survey, organisations, ... and revenue forecasting. Visiongain,s new ...
(Date:5/2/2016)... , May 2, 2016 Q ... its technology partner Mannin Research Inc. will be attending ... which takes place from May 1-5, 2016 in ... be meeting with its vendors and research partners. The ... development goals and other collaborative opportunities for the MAN-01 ...
(Date:4/29/2016)... ... ... The MIT bioLogic design team has won multiple A' Design Awards ... applied to fabric and formed into living interfaces between body and environment. They found ... team harvested Natto cells and applied them to fabric with custom 3D printers.The cell-infused ...
Breaking Biology Technology: