Flatworms left in sunlight spur investigations into rare metabolic disordersMay 31, 2016
A type of flatworm could be a new weapon in the hunt for better ways to treat a group of diseases that can cause extreme sensitivity to light, facial hair growth, and hallucinations, according to a study published in the journal eLife.
Porphyrias are a group of rare metabolic disorders characterized by red and purple pigments accumulating in the body. With the accidental discovery that the skin color of the flatworm Schmidtea mediterranea (S. mediterranea) changes under prolonged exposure to sunlight, these animals could provide a new model for studying the diseases.
Faculty and student researchers from Keene State College, New Hampshire, show that the flatworm generates light-activated molecules called porphyrins in its skin pigment cells using the same biochemical pathway as that involved in human porphyrias.
Their research developed from the unexpected observation by undergraduate students that the flatworms they were investigating changed color from brown to white when exposed to sunlight for several days. It could now lead to future drug development to meet patient demands for more effective treatments.
"Porphyrias are typically caused by inherited mutations that involve a buildup of porphyrins in various parts of the body. Although naturally created during the generation of heme, a substance required for oxygen transport in red blood cells, porphyrins can have toxic effects when their levels increase," says Jason Pellettieri, corresponding author and Associate Professor of Biology at Keene State College.
"For example, porphyrins deposited in the skin cause swelling, blistering, and lesions upon exposure to bright light. Neurological issues can also arise, ranging from anxiety and confusion to seizures or paralysis. These episodes, which can last for weeks, can be triggered by drugs, hormonal changes, and dieting or fasting."
The porphyrins in S. mediterranea give rise to their normal skin pigmentation. When the animals are exposed to intense light for extended periods of time (a situation unlikely to occur in the wild), porphyrin production leads to pigment cell loss, changing the animals' skin color to white.
To investigate this photosensitivity, the researchers first tested infrared and ultraviolet lights on the flatworms, which had no effect on their skin. In contrast, intense visible light altered their coloring, with just over half of them developing one or more small tissue lesions.
"Our findings show that prolonged light exposure eliminates the flatworms' pigment cells through a mechanism involving porphyrin-dependent photosensitization. The animals then repigment when they are no longer exposed to light," explains lead author Bradford Stubenhaus.
During the course of the research, the team also noticed a positive relationship between how long the flatworms were fasted before light exposure and the extent of their photosensitivity.
To document this relationship, they starved the animals for one, seven, 14 or 30 days before exposing them to light. Depigmentation was strongly accelerated with starvation, and then reversed with a single feeding 24 hours before light exposure.
These discoveries suggest that S. mediterranea could help identify new treatments for easing porphyrin-mediated photosensitivity or separating the relationship between dieting or fasting and the onset of disease symptoms.
"Although porphyrias are usually manageable diseases, reliance on the mainstay treatment, namely intravenous heme, or liver transplantation, for more severe cases can result in significant complications. There are also no approved preventative therapies for patients who suffer recurrent attacks," says Pellettieri.
"Our studies show that flatworms such as S. mediterranea could potentially change this. They have recently emerged as a useful model for human disorders, including Usher syndrome - a genetic disorder that affects vision, hearing, and sometimes balance - and cystic kidney disease. We can now add porphyria to this growing list, with plans to use the animals to screen for novel therapies in the near future."
The paper 'Light-induced depigmentation in planarians models the pathophysiology of acute porphyrias' can be freely accessed online at eLife.14175">http://dx.doi.org/10.7554/eLife.14175. Contents, including text, figures, and data, are free to reuse under a CC BY 4.0 license.
Emily Packer, eLife
Kelly Ricaurte, Keene State College
eLife is a unique collaboration between the funders and practitioners of research to improve the way important research is selected, presented, and shared. eLife publishes outstanding works across the life sciences and biomedicine -- from basic biological research to applied, translational, and clinical studies. All papers are selected by active scientists in the research community. Decisions and responses are agreed by the reviewers and consolidated by the Reviewing Editor into a single, clear set of instructions for authors, removing the need for laborious cycles of revision and allowing authors to publish their findings quickly. eLife is supported by the Howard Hughes Medical Institute, the Max Planck Society, and the Wellcome Trust. Learn more at elifesciences.org.
About Keene State College
Keene State College is a preeminent public liberal arts college that ensures student access to world-class academic programs. Integrating academics with real-world application and active community and civic engagement, Keene State College prepares graduates to meet society's challenges by thinking critically, acting creatively, and serving the greater good. To learn more about Keene State College, visit http://www.keene.edu.
Related Biology Articles:
A new bioinformatics tool to compare genome data has been developed by teams from the Max F.
In balancing speed and accuracy to duplicate DNA and produce proteins, Rice University researchers find evolution determined that speed is favored much more.
Skin color patterns in animals arise from microscopic interactions among colored cells that obey equations discovered by Alan Turing.
In contrast to other members of the Drosophila family, the spotted-wing fly D. suzukii deposits its eggs in ripe fruits.
Professor Henry Heng's team, from the medical school at Wayne State University, has published a perspective article titled A Systems Biology Perspective on Molecular Cytogenetics to address the issue.
Messenger RNAs bearing the genetic information for the synthesis of proteins are delivered to defined sites in the cell cytoplasm by molecular motors.
Akira Kudo at Tokyo Institute of Technology(Tokyo Tech) and colleagues report in Scientific Reports, December 2016, that live-imaging and transcriptome analysis of medaka fish transgenic lines lead to immediate alteration of cells responsible for bone structure formation.
Understanding how the nervous system of the roundworm C. elegans works will give insights into how our vastly more complex brains function and is the subject of a paper in Nature Methods.
The use of Camelid antibodies has important implications for future development of reagents for diagnosis and therapeutics in diseases involving a group of enzymes called serine proteases.
Virtually all membrane proteins have been reported to be organized as clusters on cell surfaces, when in fact many of them are just single proteins which have been counted multiple times.
Related Biology Reading:
Biology (Quick Study Academic)
by Inc. BarCharts (Author)
BarCharts’ best-selling quick reference to biology has been updated and expanded in this latest edition. With updated content and an additional panel of information, this popular guide is not only an essential companion for students in introductory biology courses but also a must-have refresher for students in higher-level courses. Author Randy Brooks, PhD, a scientist and university professor, has a gift for making the complicated subject of biology easy to understand, from evolution to population genetics―without the fluff. In this new edition, you will find more coverage of the... View Details
Biology for Dummies
by René Fester Kratz (Author), Donna Rae Siegfried (Author)
An updated edition of the ultimate guide to understanding biology
Ever wondered how the food you eat becomes the energy your body needs to keep going? The theory of evolution says that humans and chimps descended from a common ancestor, but does it tell us how and why? We humans are insatiably curious creatures who can't help wondering how things work — starting with our own bodies. Wouldn't it be great to have a single source of quick answers to all our questions about how living things work? Now there is.
From molecules to animals, cells to ecosystems, Biology For... View Details
Miller & Levine Biology: 2010 On-Level, Student Edition
by Kenneth R. Miller (Author), Joseph S. Levine (Author)
Miller & Levine Biology Curriculum - High School
The respected author team of Ken Miller and Joe Levine are back with a new edition of biology books to inspire students to interact with trusted and up-to-date biology content. The authors' unique storytelling style engages students in biology, with a greater focus on written and visual analogies.View Details
Biology: The Ultimate Self Teaching Guide - Introduction to the Wonderful World of Biology
by Bobbi Leigh Templeton (Author)
Your Introductory Guide to Biology - 2ND EDITION! Free bonus inside! (Right after Conclusion) - Get limited time offer, Get your BONUS right NOW! If you have ever wanted to know more about biology, but thought it would too confusing, then this is the book for you. We take the concepts of biology and put them in simple terms, allowing you to better understand the amazing diversity of our planet! With An Introduction to the Wonderful World of Biology, you'll learn about how cells do the work that supports life. You will also come to appreciate the cycle of life, how species... View Details
Campbell Biology (10th Edition)
by Jane B. Reece (Author), Lisa A. Urry (Author), Michael L. Cain (Author), Steven A. Wasserman (Author), Peter V. Minorsky (Author), Robert B. Jackson (Author)
The Tenth Edition of the best-selling text Campbell BIOLOGY helps launch you to success in biology through its clear and engaging narrative, superior pedagogy, and innovative use of art and photos to promote student learning.
The Tenth Edition helps you develop a deeper understanding of biology by making connections visually across chapters and building the scientific skills needed for success in upper-level courses.New Make Connections Figures pull together content... View Details
E-Z Biology (Barron's E-Z Series)
by Gabrielle I. Edwards (Author), Cynthia Pfirrmann (Author)
Known for many years as Barron’s Easy Way Series, the new editions of these popular self-teaching titles are now Barron’s E-Z Series. Brand-new cover designs reflect all new page layouts, which feature extensive two-color treatment, a fresh, modern typeface, and more graphic material than ever― charts, graphs, diagrams, instructive line illustrations, and where appropriate, amusing cartoons. Meanwhile, the quality of the books’ contents remains at least as high as ever. Barron’s E-Z books are self-help manuals focused to improve students’ grades in a wide... View Details
The Biology Coloring Book
by Robert D. Griffin (Author), Cinthea Vadala (Illustrator)
Readers experience for themselves how the coloring of a carefully designed picture almost magically creates understanding. Indispensable for every biology student. View Details
by Sylvia S. Mader Dr. (Author), Michael Windelspecht (Author)
NOTE: This is a standalone book and doesn't include an access code.
THE MADER/WINDELSPECHT STORY…
The twelfth edition of Biology is a traditional, comprehensive introductory biology textbook, with coverage from Cell Structure and Function to the Conservation of Biodiversity. The book, which centers on the evolution and diversity of organisms, is appropriate for any one- or two-semester biology course.
Biology, 12th Edition is the epitome of Sylvia Mader's expertise. Its concise, precise writing-style employs lucid language to present... View Details
Campbell Biology (11th Edition)
by Lisa A. Urry (Author), Michael L. Cain (Author), Steven A. Wasserman (Author), Peter V. Minorsky (Author), Jane B. Reece (Author)
Note: You are purchasing a standalone product; MyLab™ & Mastering™ does not come packaged with this content. Students, if interested in purchasing this title with MyLab & Mastering, ask your instructor for the correct package ISBN and Course ID. Instructors, contact your Pearson representative for more information.
If you would like to purchase boththe physical text and MyLab & Mastering, search for:
0134082311 / 9780134082318 Campbell Biology Plus MasteringBiology... View Details
Behave: The Biology of Humans at Our Best and Worst
by Robert M. Sapolsky (Author)
A New York Times Bestseller.
"Hands-down one of the best books I’ve read in years. I loved it."— Dina Temple-Raston, The Washington Post
“It’s no exaggeration to say that Behave is one of the best nonfiction books I’ve ever read.” —David P. Barash, The Wall Street Journal
From the celebrated neurobiologist and primatologist, a landmark, genre-defining examination of human behavior, both good and bad, and an answer to the question: Why do we do the things we do?
Sapolsky's storytelling... View Details