Navigation Links
Regrowth of Zebrafish's Tail Fin may Offer Clues for Treating Human Injuries

If a zebrafish loses a chunk of its tail fin, it’ll grow back within a week. //Like lizards, newts, and frogs, a zebrafish can replace surprisingly complex body parts. A tail fin, for example, has many different types of cells and is a very intricate structure. It is the fish version of an arm or leg.

The question of how cold-blooded animals re-grow missing tails and other appendages has fascinated veterinary and medical scientists. They also wonder if people, and other warm-blooded animals that evolved from these simpler creatures, might still have untapped regenerative powers hidden in their genes.

People are constantly renewing blood components, skeletal muscles and skin. We can regenerate liver tissue and repair minor injuries to bone, muscle, the tips of our toes and fingers, and the corneas of our eyes. Finding out more about the remarkable ability of amphibians and fish to re-grow complex parts might provide the information necessary to create treatments for people whose hearts, spinal cords, eyes or arms and legs have been badly hurt.

Scientists have discovered some of the genes and cell-to-cell communication pathways that enable zebrafish to restore their tail fins.

“The ability to regenerate body parts such as those that are damaged by injury or disease,” said Dr. Randall Moon, professor of pharmacology at the University of Washington (UW), an investigator of the Howard Hughes Medical Institute, and a researcher in the UW Institute for Stem Cell and Regenerative Medicine, “involves creating cells that can take any number of new roles. This can be done by re-programming cells that already have a given function or by activating resident stem cells.”

Developmental biologists know that a particular kind of cell-to-cell communication, called Wnt/Beta-catenin signaling, regulates the fate of these as-yet undeveloped cells as an embryo forms. Through a cascade of signals, cells waiting for their calling learn which spot to take to help form the embryo, what kinds of cells to become there, and how many cells like themselves should be reproduced. These streams of signals also tell stem cells in adult organisms what functions to undertake. Once tissue formation starts, something has to tell it to stop before growth gets out of hand.

In the Dec. 21, 2006 online edition of the scientific journal Development, UW researchers report on laboratory evidence that suggests that Wnt/Beta signaling also promotes the regeneration of tail fins in zebrafish. Another, distinct signaling pathway activated by a different kind of Wnt protein called Wnt5b, turns down the genes that are turned on by Wnt/Beta-catenin, impairs cell proliferation, and inhibits fin regeneration. Fish that have a mutant Wnt5b protein regenerate missing tails very quickly. Too much of another related protein, Wnt8, also increases cell proliferation in the regenerating fin.

“We can actually increase the rate of regeneration by turning on these genes,” Moon said.

The researchers also noted, “We show that Wnt/Beta-catenin signaling is activated in the regenerating zebrafish tail and is required for the formation and subsequent proliferation of the progenitor cells of the blastema.” A blastema is a little nub of cells that directs regeneration, much like the conductor of an orchestra. By directing cell communication, these few cells grow into an organ or body part, in this case, a tail fin.

“It is most likely the inability of humans to form a blastema in the first place that renders us unable to re-grow arms and legs,” said Cristi Stoick-Cooper, a graduate student in the multidisciplinary Neurobiology and Behavior program at the UW, who, with Gilbert Weidinger, now of the Technical University of Dresden (TUD), Germany, was first co-author of the study. The research was done in Moon’s lab.

“Our study is the first to identify a gene (Wnt5b) that inhibit s regeneration,” said Weidinger, a former UW postdoctoral fellow who leads the Wnt Signaling in Development and Regeneration research group at the TUD’s Biotechnology Center. “This is very exciting, because this gene might also inhibit regeneration in mammals and man. So, if we find ways of interfering with the function of Wnt5b, we might be able to promote regeneration.”

Moon added that, because the same genes for turning on and turning off growth and development are found in humans, and drugs exist that can regulate this pathway, the findings are directly relevant to future testing of whether scientists can increase the capacity of humans to re-build damaged organs.


Related medicine news :

1. Pancreatitis: Minimially Invasive Procedure Offers Long-Term Pain Relief
2. Drug Offers Hope for Alzheimers disease
3. Drug Firm Offers to Donate Smallpox Vaccine
4. Stem Cells Found To Offer Promise For Hair Growth
5. fMRI Offers Insight Into An Infants Brain
6. Diet Found To Offer Protection Against Leukemia
7. Gel Offers A More Targeted Approach
8. Umbilical Cord Blood Offers Hope For Patients Who Require Bone Marrow Transplants
9. Olive Oil Found To Offer A Protective Effect Against Breast Cancer
10. A New Product Offering protection against anthrax
11. Surgery Offers Better Treatment For Third Degree Piles
Post Your Comments:

(Date:11/26/2015)... ... November 26, 2015 , ... WorldCare ... participated in the 61st annual Employee Benefits Conference. The Employee Benefits Conference was ... November 8th through Wednesday, November 11th, 2015. The conference was held at the ...
(Date:11/26/2015)... ... November 26, 2015 , ... Indosoft Inc., developer and ... an application server to improve system efficiency and reliability. , The new Q-Suite 6 ... these standards, the system avoids locking itself into a specific piece of software for ...
(Date:11/25/2015)... ... November 25, 2015 , ... ... the perfect dish and pleasing the palates of attendees is of the utmost ... dish to a seasonal get-together, give these recipes a try this holiday season. ...
(Date:11/25/2015)... ... November 25, 2015 , ... TyloHelo ... parts and accessories. , Sauna accessories help improve the bather experience in the ... From basic styles for the purist looking for simplicity in design to accessories ...
(Date:11/25/2015)... Rouge, LA (PRWEB) , ... November 25, 2015 , ... ... in the United States District Court of Connecticut on behalf of a home health ... behalf of all current or former home health care workers employed by Humana, Inc., ...
Breaking Medicine News(10 mins):
(Date:11/26/2015)... , Nov. 26, 2015 Research and ... of the "2016 Future Horizons and Growth ... Market: Supplier Shares, Country Segment Forecasts, Competitive Intelligence, ... --> --> ... of the Italian therapeutic drug monitoring market, including ...
(Date:11/26/2015)... 2015 ... the  "2016 Future Horizons and Growth ... Marker Testing Market: Supplier Shares, Competitive ... offering.  --> ) ... "2016 Future Horizons and Growth Strategies ...
(Date:11/25/2015)... SYDNEY , Nov. 26, 2015  The total global ... nearly 7% over 2015-2016. Latin America ... Asia , (excluding Japan ), is ... continues to face increased healthcare expenditure. In 2013-2014, ... expenditure declined from 43.5% in 2008-2009 to 41.2% in 2013-2014. ...
Breaking Medicine Technology: