Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Spleen may be source of versatile stem cells

20.01.2005


Cells have protein associated with embryonic development, limb regeneration



A year ago, Massachusetts General Hospital (MGH) researchers discovered that the spleen might be a source of adult stem cells that could regenerate the insulin-producing islets of the pancreas. In a follow-up to that unexpected finding, members of the same team now report that these potential adult stem cells produce a protein previously believed to be present only during the embryonic development of mammals.

The finding both supports the existence of these splenic stem cells and also suggests they may be able to produce an even greater variety of tissues. The report appears in the January 19 issue of SAGE KE (http://sageke.sciencemag.org ), an online resource on the science of aging from the publishers of the journal Science.


"There may be a previously undiscovered pocket of primitive stem cells in the spleen that are important for healing several types of damage or injury," says Denise Faustman, MD, PhD, director of the MGH Immunobiology Laboratory and senior author of the SAGE KE report. "If so, these cells could have much broader therapeutic applications than suggested by our earlier work."

In 2001 Faustman’s team found that a treatment designed to address the autoimmune reaction underlying type 1 diabetes actually cured the disease in diabetic mice. Late in 2003 they reported the mechanism behind the earlier discovery: cells from the spleens of donor mice – intended to train the diabetic animals’ immune systems not to attack islet cells – were actually producing new islets. The result suggested that the adult spleen – previously regarded as playing a fairly minor role in regenerative medicine – might contain a population of potential islet stem cells.

In their pursuit of that finding, the MGH researchers investigated the possible presence of a protein called Hox11 in these cells. In mammals, Hox11 is a controller of key steps in embryonic development – including the formation of the spleen – but it was not known to be present in adults under normal circumstances. In some other animals, however, the protein has an intriguing function: when creatures like newts regenerate a lost limb or tail, production of Hox11 is radically increased.

As reported in their SAGE KE article, the MGH team did find that Hox11 was produced in the spleens of adult mice by the same cells that regenerated the islets in the earlier study. They also found that these cells did not produce a protein known to be associated with a cellular commitment to develop into a particular type of tissue. Without that commitment, the splenic cells may be able to differentiate into a wider variety of cells than can adult stem cells from bone marrow, which do not produce Hox11.

The researchers also note that the spleen develops from embryonic tissue that is known not only to generate precursors to many types of blood cells, a function shared by the bone marrow, but potentially to form such diverse organs as the small intestine, uterus, vascular system and lung. They theorize that a pocket of these uncommitted cells might remain in the spleen though adulthood. In addition to regeneration of islets, these cells might also produce bone cells – suggested by findings from other researchers – or potentially even cells of the nervous system, development of which depends on the correct production of Hox11.

"We know that if you have a major loss of blood, the spleen is turned on to supplement the bone marrow in replenishing your blood supply. We may find that the spleen kicks in to help with many more biological emergencies. What has been considered a practically unnecessary organ may actually provide critical healing cells," says Faustman, an associate professor of Medicine at Harvard Medical School.

She adds, "This data also shows the kind of payback that can come from studies of lower animals like newts and sponges. Combining the knowledge of Hox11’s role in those animals with what we’d found about islet cell regeneration in mice helped us find this previously unknown example of normal, controlled Hox11 expression in an adult mammal."

Sue McGreevey | EurekAlert!
Further information:
http://www.mgh.harvard.edu
http://sageke.sciencemag.org
http://www.joinleenow.org

More articles from Life Sciences:

nachricht Rainbow colors reveal cell history: Uncovering β-cell heterogeneity
22.09.2017 | DFG-Forschungszentrum für Regenerative Therapien TU Dresden

nachricht The pyrenoid is a carbon-fixing liquid droplet
22.09.2017 | Max-Planck-Institut für Biochemie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>