Navigation Links
Study reveals stem cells in a human parasite
Date:2/25/2013

CHAMPAIGN, lll. From the point of view of its ultimate (human) host, the parasitic flatworm Schistosoma mansoni has a gruesome way of life. It hatches in feces-tainted water, grows into a larva in the body of a snail and then burrows through human skin to take up residence in the veins. Once there, it grows into an adult, mates and, if it's female, starts laying eggs. It can remain in the body for decades.

A new study offers insight into the cellular operations that give this flatworm its extraordinary staying power. The researchers, from the University of Illinois, demonstrated for the first time that S. mansoni harbors adult, non-sexual stem cells that can migrate to various parts of its body and replenish tissues. Their report appears in the journal Nature.

According to the World Health Organization, more than 230 million people are in need of treatment for Schistosoma infections every year. Most live in impoverished areas with little or no access to clean water. Infection with the worm (also known as a blood fluke) can lead to damaging inflammation spurred by the presence of the worm's eggs in human organs and tissues.

"The female lays eggs more or less continuously, on the order of hundreds of eggs per day," said U. of I. cell and developmental biology professor and Howard Hughes Medical Institute Investigator Phillip Newmark, who led the study with postdoctoral researcher James J. Collins III.

"The eggs that don't get excreted in the feces to continue the life cycle actually become embedded inside host tissues, typically the liver, and those eggs trigger a massive inflammatory response that leads to tissue damage."

Children are especially vulnerable to the effects of infection, in some cases experiencing delays in growth and brain development as a result of chronic inflammation brought on by the parasites.

The new study began with an insight stemming from years of work on a different flatworm, the planarian, in Newmark's lab. Collins thought that schistosomes might make use of the same kinds of stem cells (called neoblasts in planarians) that allow planarians to regenerate new body parts and organs from even tiny fragments of living tissue.

"It just stood to reason that since schistosomes, like planaria, live so long that they must have a comparable type of system," Collins said. "And since these flatworms are related, it made sense that they would have similar types of cells. But it had never been shown."

In a series of experiments, Collins found that the schistosomes were loaded with proliferating cells that looked and behaved like planarian neoblasts, the cells that give them their amazing powers of regeneration. Like neoblasts, the undifferentiated cells in the schistosomes lived in the mesenchyme, a kind of loose connective tissue that surrounds the organs. And like neoblasts, these cells duplicated their DNA and divided to form two "daughter" cells, one of which copied its DNA again, a process that normally precedes cell division.

"Stem cells do two things," Newmark said. "They divide to make more stem cells and they give rise to cells that can differentiate."

Collins had labeled the cells with fluorescent markers. This allowed him to watch how they behaved. He noted that over the course of a few days, some of the labeled cells migrated into the gut or muscle, to become part of those tissues.

"We label the cells when they're born and then we see what they grow up to become," Collins said. "This is not conclusive evidence that these cells are equivalent to the planarian neoblasts, but it is consistent with the hypothesis that they are."

The researchers went deeper, determining which genes were turned on or off, up or down in the proliferating cells as compared with the non-dividing cells. They identified a gene in the proliferating cells that coded for a growth factor receptor very similar to one found in planarians. When the researchers switched off the parasite's ability to make use of this gene (using a technique called RNA interference in worms grown in the lab), the proliferating cells gradually died out.

"We postulated that these cells are important for the longevity of the parasite," Collins said. "Now we can start asking which genes regulate these cells."

"We started with the big question: How does a simple parasite survive in a host for decades?" Newmark said. "That implies that it has ways of repairing and maintaining its tissues. This study gives us insight into the really interesting biology of these parasites, and it may also open up new doors for making that life cycle a lot shorter."


'/>"/>

Contact: Diana Yates
diya@illinois.edu
217-333-5802
University of Illinois at Urbana-Champaign
Source:Eurekalert  

Related medicine news :

1. Climate Change May Threaten Worker Health, Productivity, Study Says
2. Without Laws, Many Tanning Salons Would Allow Kids: Study
3. Study by Allegheny General Hospital Physicians Shows Oral Immunotherapy is a Safe, Effective Alternative to Allergy Shots for Ragweed Sufferers
4. Doctors Health Press Reports on Study: Heart-Healthy Linoleic Acid Levels Decrease with Age
5. Columbus Center for Women’s Health Research is participating in an International Study for a New “Use-as-Needed” Treatment for Women with Sexual Dysfunction
6. UNC-led study documents head and neck cancer molecular tumor subtypes
7. Breast Reconstruction Using Womens Own Tissue Appears Safe: Study
8. Israel rocket attacks increase miscarriage likelihood -- Ben-Gurion U. research study
9. Plastics Chemical BPA Common in Preemie ICU: Study
10. Fitness Expert Lorna Kleidman Responds to Study Claiming Exercise Can Decrease Risk of Dementia
11. Dialysis Catheters Tied to Higher Risk for Infection, Death, Study Finds
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Study reveals stem cells in a human parasite
(Date:6/27/2016)... ... ... TherapySites, the leading website and online marketing ... Association. This new relationship allows TherapySites to continue to extend their online ... and promotional offers. , "TCA is extremely excited about this new partnership, as ...
(Date:6/27/2016)... ... June 27, 2016 , ... TopConsumerReviews.com recently awarded their highest five-star rating ... Millions of individuals in the United States and Canada wear eyeglasses. Once considered to ... correct vision and make a fashion statement. Even celebrities use glasses as a way ...
(Date:6/26/2016)... (PRWEB) , ... June 26, 2016 , ... Pixel Film ... Pro X. , "Film editors can give their videos a whole new perspective by ... Austin - CEO of Pixel Film Studios. , ProSlice Levels contains over 30 ...
(Date:6/26/2016)... ... June 26, 2016 , ... ... have been diagnosed with endometriosis. These women need a treatment plan to not ... comprehensive approach that can help for preservation of fertility and ultimately achieving a ...
(Date:6/25/2016)... ... ... temporary closing of Bruton Memorial Library on June 21 due to a possible lice infestation, ... aspect of head lice: the parasite’s ability to live away from a human host, and ... necessary one in the event that lice have simply gotten out of control. , As ...
Breaking Medicine News(10 mins):
(Date:6/23/2016)... Research and Markets has announced the addition of ... report to their offering. ... kidney failure, it replaces the function of kidneys by removing ... thus the treatment helps to keep the patient body,s electrolytes ... Increasing number of ESRD patients & substantial healthcare expenditure ...
(Date:6/23/2016)... Research and Markets has announced the addition of ... Forecast to 2022" report to their offering. ... date financial data derived from varied research sources to present ... impact on the market during the next five years, including ... sub markets, regional and country level analysis. The report provides ...
(Date:6/23/2016)... and INDIANAPOLIS , June 23, 2016 ... Lilly Diabetes Tomorrow,s Leaders Scholarship is any indication, the ... announced today online at www.diabetesscholars.org by the ... diabetes stand in the way of academic and community ... Foundation,s scholarship program since 2012, and continues to advocate ...
Breaking Medicine Technology: