Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists Find Stem Cells For the First Time in the Pituitary

30.04.2008
Their presence in the hormone-secreting gland of mice suggests a means of adapting to stress and life changes
A team of researchers led by scientists at Cold Spring Harbor Laboratory have for the first time identified stem cells that allow the pituitary glands of mice to grow even after birth. They found that, in contrast to most adult stem cells, these cells are distinct from those that fuel the initial growth of this important organ. The results suggest a novel way that the hormone-secreting gland may adapt, even in adolescents and adults, to traumatic stress or to normal life changes like pregnancy.

Seeking Adult Stem Cells
Maturity, in some respects, brings diminished possibilities. As a fertilized egg cell repeatedly divides to grow into a mature animal, most of the resulting cells become ever more specialized. But a small number of cells, known as stem cells, remain uncommitted even as they spawn more specialized progeny. The most versatile stem cells, taken from days-old embryos, are able to form any cell type — but studying them in people is controversial. Even in adults, however, other types of stem cell persist that have a more limited repertoire. Some replace specific cells as they wear out; others help to rebuild damaged tissues. Still other stem cells are suspected by some scientists of starting or maintaining cancers.

In spite of their importance, stem cells are hard to spot among the multitude of cells in complex tissue. Several years ago, neuroscientist Grigori Enikolopov, Ph.D., an associate professor at Cold Spring Harbor Laboratory (CSHL), and his colleagues developed a tool to look for stem cells that give rise to new adult brain cells. Researchers had known that a gene called Nestin was active in these neural stem cells. The CSHL team genetically engineered mice so that the same conditions that activate Nestin in a particular cell also make it glow green under ultraviolet light.

Using these mice gives researchers an important pointer to cells that may be adult stem cells. Almost 100 research teams around the world have now used these special mice to help find adult stem cells in hair follicles, liver, muscle, and other tissues.

Looking at the pituitary
One place where stem cells had been suspected — but never found — is the pituitary gland. This organ, which in people is about the size of a pea, sits at the base of the brain, where it secretes hormones that regulate various processes throughout the body. In mice, the gland develops in the embryo, but then has a second growth spurt. “A few weeks after they are born,” says Dr. Enikolopov, “the pituitary undergoes massive expansion” that suggests a role for adult stem cells.

Anatoli Gleiberman, Ph.D., a researcher in the lab of pituitary expert M. Geoff Rosenfeld at the University of California, San Diego, initiated a collaboration between the two labs to look for pituitary stem cells. The researchers used the Nestin-tracking mice to identify candidate cells in the anterior pituitary, the section of the organ that secretes hormones. They then used other techniques to show that these are true stem cells. “There are six main lineages in the adult pituitary,” says Dr. Enikolopov, “and we can demonstrate that one adult stem cell can generate all six lineages,” with each cell type secreting a different hormone.

A distinct kind of stem cell
These cells differ from most adult stem cells, however. “In most cases that we know,” says Dr. Enikolopov, “cells that become stem cells of the adult have been also contributing to embryonic development and continue to serve as stem cells in the adult.” The research team demonstrated that adult stem cells in the pituitary did not help construct the embryonic organ.

Their research, the scientists suggest, indicates that the adult mouse pituitary includes two similar — but not identical — types of hormone-producing cells: some that grew in the developing embryo, and some that appeared later. They speculate that having two sets of cells may let the organ respond differently to changing body conditions. Dr. Enikolopov notes that hormones strongly influence human neuropsychiatric phenomena, including stress and depression that are his main research focus. “All are mediated through the pituitary,” he said, so changes that happen during the later growth of the gland could have lasting effects.

“Genetic approaches identify adult pituitary stem cells” appears in the April 29, 2008 edition of the Proceedings of the National Academy of Sciences. Along with Dr. Enikolopov, Dr. Michael Geoff Rosenfeld, who is a Howard Hughes Medical Institute Investigator at the University of California at San Diego School of Medicine, is a corresponding author of the paper. The complete citation is as follows: Anatoli S. Gleiberman, Tatyana Michurina, Juan M. Encinas, Jose L. Roig, Peter Krasnov, Francesca Balordi, Gord Fishell, Michael G. Rosenfeld, and Grigori Enikolopov. The paper is available online at http://www.pnas.org/cgi/doi/10.1073/pnas.0801644105.

Cold Spring Harbor Laboratory is a private, nonprofit research and education institution dedicated to exploring molecular biology and genetics in order to advance the understanding and ability to diagnose and treat cancers, neurological diseases and other causes of human suffering.

Jim Bono | EurekAlert!
Further information:
http://www.cshl.edu
http://www.pnas.org/cgi/doi/10.1073/pnas.0801644105

Further reports about: Embryo Enikolopov Organ Stem hormone pituitary

More articles from Life Sciences:

nachricht The interactome of infected neural cells reveals new therapeutic targets for Zika
23.01.2017 | D'Or Institute for Research and Education

nachricht Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery
20.01.2017 | GSI Helmholtzzentrum für Schwerionenforschung GmbH

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Quantum optical sensor for the first time tested in space – with a laser system from Berlin

For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.

According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

New technology for mass-production of complex molded composite components

23.01.2017 | Process Engineering

Quantum optical sensor for the first time tested in space – with a laser system from Berlin

23.01.2017 | Physics and Astronomy

The interactome of infected neural cells reveals new therapeutic targets for Zika

23.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>