Scientists identify gene that puts brakes on tissue growth

January 22, 2020

The planarian flatworm is a simple animal with a mighty and highly unusual ability: it can regenerate itself from nearly every imaginable injury, including decapitation. These tiny worms can regrow any missing cell or tissue -- muscle, neurons, epidermis, eyes, even a new brain.

Since the late 1800s, scientists have studied these worms to better understand fundamental principles of natural regeneration and repair, information that could provide insights into tissue healing and cancer. One mechanism that is yet unknown is how organisms like these control the proportional scaling of tissue during regeneration.

Now, two Northwestern University molecular biologists have identified the beginnings of a genetic signaling pathway that puts the brakes on the animal's growth. This important process ensures the appropriate amount of tissue growth in these highly regenerative animals.

"These worms have essentially discovered a natural form of regenerative medicine through their evolution," said Christian Petersen, who led the research. "Planarians can regenerate their whole lives, but how do they limit their growth? Our discovery will improve understanding of the molecular components and organizing principles that govern perfect tissue restoration."

The findings ultimately may have important ramifications for novel tissue engineering methods or strategies to promote natural repair mechanisms in humans.

Petersen is an associate professor of molecular biosciences in Northwestern's Weinberg College of Arts and Sciences. He and Erik G. Schad, a graduate student in Petersen's lab, conducted the study.

The results were published in the Jan. 20 issue of the journal Current Biology. Petersen is the corresponding author, and Schad is the paper's first author.

The researchers have identified a control system for limiting regeneration and also a new mechanism to explain how stem cells can influence growth. Specifically, Petersen and Schad discovered that a gene called mob4 suppresses tissue growth in the animals. When the researchers inhibited the gene in experiments, the animal grew to twice its normal size.

The gene, they found, works in a rather surprising way: by preventing the descendants of stem cells from producing a growth factor called Wnt, a protein released from cells to communicate across distances. The Wnt signaling pathway is known to play a role in cancer cell regeneration.

Planarians are 2 to 20 millimeters in size and have a complex anatomy with around a million cells. They live in freshwater ponds and streams around the world. The worm's genome has been sequenced, and its basic biology is well-characterized, making planarians popular with scientists.
-end-
Petersen also is a member of the Robert H. Lurie Comprehensive Cancer Center of Northwestern University.

The title of the paper is "STRIPAK Limits Stem Cell Differentiation of a WNT Signaling Center to Control Planarian Axis Scaling."

Northwestern University

Related Stem Cells Articles from Brightsurf:

SUTD researchers create heart cells from stem cells using 3D printing
SUTD researchers 3D printed a micro-scaled physical device to demonstrate a new level of control in the directed differentiation of stem cells, enhancing the production of cardiomyocytes.

More selective elimination of leukemia stem cells and blood stem cells
Hematopoietic stem cells from a healthy donor can help patients suffering from acute leukemia.

Computer simulations visualize how DNA is recognized to convert cells into stem cells
Researchers of the Hubrecht Institute (KNAW - The Netherlands) and the Max Planck Institute in Münster (Germany) have revealed how an essential protein helps to activate genomic DNA during the conversion of regular adult human cells into stem cells.

First events in stem cells becoming specialized cells needed for organ development
Cell biologists at the University of Toronto shed light on the very first step stem cells go through to turn into the specialized cells that make up organs.

Surprising research result: All immature cells can develop into stem cells
New sensational study conducted at the University of Copenhagen disproves traditional knowledge of stem cell development.

The development of brain stem cells into new nerve cells and why this can lead to cancer
Stem cells are true Jacks-of-all-trades of our bodies, as they can turn into the many different cell types of all organs.

Healthy blood stem cells have as many DNA mutations as leukemic cells
Researchers from the Princess Máxima Center for Pediatric Oncology have shown that the number of mutations in healthy and leukemic blood stem cells does not differ.

New method grows brain cells from stem cells quickly and efficiently
Researchers at Lund University in Sweden have developed a faster method to generate functional brain cells, called astrocytes, from embryonic stem cells.

NUS researchers confine mature cells to turn them into stem cells
Recent research led by Professor G.V. Shivashankar of the Mechanobiology Institute at the National University of Singapore and the FIRC Institute of Molecular Oncology in Italy, has revealed that mature cells can be reprogrammed into re-deployable stem cells without direct genetic modification -- by confining them to a defined geometric space for an extended period of time.

Researchers develop a new method for turning skin cells into pluripotent stem cells
Researchers at the University of Helsinki, Finland, and Karolinska Institutet, Sweden, have for the first time succeeded in converting human skin cells into pluripotent stem cells by activating the cell's own genes.

Read More: Stem Cells News and Stem Cells Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.