Navigation Links
Reprogrammable cell type depends on a single gene to keep its identity
Date:12/1/2008

Scientists at St. Jude Children's Research Hospital have discovered that a certain differentiated cell type is so ready to change its identity that it requires the constant expression of a gene called Prox1 to dissuade it.

The researchers showed that Prox1 acts as a two-way switch whose inactivity is sufficient to reprogram a specialized type of cell, called a lymphatic endothelial cell (LEC). In the absence of active Prox1, the LEC actually loses its identity and assumes characteristics of a blood endothelial cell (BEC), which plays a different role in the body. Endothelial cells line the inside of blood and lymphatic vessels. The results of the study appear in the Dec. 1, 2008, issue of the journal Genes & Development.

The new finding is important because it helps to explain how during embryogenesis a critical set of vessels called the lymphatic vasculature arises from veins; and how lymphatic vessels can eventually lose their characteristics and acquire features typical of blood vessels and transport blooda trick that might, for example, let the body quickly build up a supply of additional blood vessels when there is an emergency need for more nourishment in a certain area. A switch from lymphatic to blood vessels might also be triggered by certain tumors trying to nourish their own growth.

The lymphatic vasculature is a vital network of vessels that performs important housekeeping functions in the body. Specifically, it drains fluids that normally escape from capillaries, which provide nutrients to the body's cells. The lymphatic vasculature is also part of the immune system that traps and attacks invading organisms and is a primary route for malignant tumor dissemination to the regional lymph nodes.

"The new finding adds to a growing body of evidence showing that some fully differentiated cell types can exhibit great plasticity and upon reprogramming revert back to their previous identity," said Guillermo Oliver, Ph.D., a member of the St. Jude Department of Genetics and Tumor Cell Biology. Differentiation is the process by which genetic activity causes an immature cell type to acquire specific characteristics of a particular mature adult cell type.

"In the last few years, some discoveries have challenged the long-standing belief that cell differentiation is an irreversible final process," said Oliver, the paper's senior author. "St. Jude researchers showed that lymphatic endothelial cells are one of the few examples of differentiated cell types that require constant expression of a specific gene to maintain their identity. This current work builds on our previous results that demonstrated the key role Prox1 plays in the formation of the lymphatic vasculature."

As an important resource for this finding, Oliver's team used a special mouse strain in which the Prox1 genes could be deleted from LECs at different times during development or after birth.

The St. Jude team found that deletion of Prox1 in LECs promoted their reprogramming into BECs as indicated by the expression of specific LEC and BEC proteins. In addition, the newly reprogrammed cells gained some specific features typical of blood vessels. For example, the cells were surrounded by pericytessmall cells that help support endothelial cellsand blood abnormally entered the reprogrammed mutant lymphatic vessels.

Finally, the researchers used a trick that enabled them to block the ability of isolated cultured LECs to produce the Prox1 proteins to further demonstrate that Prox1 activity is required by LECs to maintain their identity.

"The new insights offered by this research will give us a better understanding of how to convert one cell into another and the eventual use of the new therapeutic approaches in pathological conditions and tumors," Oliver said.


'/>"/>

Contact: Summer Freeman
summer.freeman@stjude.org
901-595-3061
St. Jude Children's Research Hospital
Source:Eurekalert

Related biology news :

1. Environmental fate of nanoparticles depends on properties of water carrying them
2. Nature study demonstrates that bacterial clotting depends on clustering
3. Model for the assembly of advanced, single-molecule-based electronic components developed at Pitt
4. Single-largest biodiversity survey says primary rainforest is irreplaceable
5. New technique captures chemical reactions in a single living cell at unprecedented resolution
6. Gene study supports single main migration across Bering Strait
7. Baumann lab identifies elusive telomere RNA subunit in single cell model
8. Ebola virus disarmed by excising a single gene
9. Blue-eyed humans have a single, common ancestor
10. Rice scientists make breakthrough in single-molecule sensing
11. Single-celled bacterium works 24-7
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/20/2016)... , May 20, 2016  VoiceIt is excited ... with VoicePass. By working together, VoiceIt ...  Because VoiceIt and VoicePass take slightly different approaches ... increases both security and usability. ... about this new partnership. "This marketing ...
(Date:5/3/2016)... May 3, 2016  Neurotechnology, a provider of ... MegaMatcher Automated Biometric Identification System (ABIS) , a ... projects. MegaMatcher ABIS can process multiple complex biometric ... combination of fingerprint, face or iris biometrics. It ... and MegaMatcher Accelerator , which have ...
(Date:4/26/2016)... 27, 2016 Research and ... Biometrics Market 2016-2020"  report to their offering.  , ... The analysts forecast the global multimodal biometrics ... during the period 2016-2020.  Multimodal biometrics ... such as the healthcare, BFSI, transportation, automotive, and ...
Breaking Biology News(10 mins):
(Date:6/24/2016)... discussions on a range of subjects including policies, debt and ... Poloz. Speaking at a lecture to the Canadian ... to the country,s inflation target, which is set by both ... "In certain areas there needs to be ... why not sit down and address strategy together?" ...
(Date:6/23/2016)... (PRWEB) , ... June 23, 2016 , ... ... is pleased to announce the launch of their brand, UP4™ Probiotics, into Target ... over 35 years, is proud to add Target to its list of well-respected ...
(Date:6/23/2016)... ... 23, 2016 , ... Charm Sciences, Inc. is pleased to ... AOAC Research Institute approval 061601. , “This is another AOAC-RI approval of the ... Vice President of Regulatory and Industrial Affairs. “The Peel Plate methods perform comparably ...
(Date:6/23/2016)... ... June 23, 2016 , ... STACS DNA Inc., the sample tracking software company, ... Crime Laboratory, has joined STACS DNA as a Field Application Specialist. , “I ... President and COO of STACS DNA. “In further expanding our capacity as a scientific ...
Breaking Biology Technology: