Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Circulating stem cells play small role in lung repair

28.07.2005


Circulating stem cells play a minor role in repairing lung damage, according to a team of scientists who used male and female chromosomal differences to analyze the repair process in lung transplant patients.

Reporting in today’s edition of the journal Transplantation, lead author Dani Zander, M.D., of The University of Texas Medical School at Houston, and colleagues at the University of Florida College of Medicine found that less than 1 percent of a certain type of reparative lung stem cell originated in the bone marrow of the transplant recipient.

"It’s possible in the future that circulating stem cells could be augmented to play a greater role in lung repair – and people are looking at ways to do that. We found that the bulk of stem cell contribution to the repair process belongs to those stem cells normally found in the lungs rather than to circulating stem cells," said Zander, who is professor and vice chair of pathology and laboratory medicine.



Stem cells are produced during adulthood in the bone marrow, where some remain while others circulate in the blood stream. Their main function is to produce all of the elements of blood. Some studies show that circulating stem cells are capable of diffentiating into other types of tissue, including lung tissue, Zander said, and this study provides evidence of differentiation.

Researchers examined lung biopsy specimens from seven male transplant recipients who had received lungs from female donors. They analyzed the origins of type II pneumocytes, a stem cell involved in the complex processes of lung repair, found in the lung tissue. Donor lungs come with their own type II pneumocytes, which in this case have two X chromosomes. Cells produced by the recipient’s bone marrow have an X and a Y (male) chromosome.

Lung transplant recipients are vulnerable to pulmonary injury from infections, rejection of the transplanted lung, ischemia, and other factors that damage the alveoli – tiny hollow sacs along the airways where the blood takes in oxygen and discards carbon dioxide.

The processes by which alveoli recover from damage are complex and incompletely understood, Zander said. Previous research showed that type II pneumocytes in the lungs are known to play a central role, but the role of the bone marrow-derived version of the cells is less clear.

"The lung has received relatively little investigation in this area," Zander said. "It’s a challenging organ to study because the air-tissue interfaces make it difficult to separate different cell types."

Applying advanced research techniques that previously had been used to analyze liver and bone marrow transplant recipients, the team found that nine of 25 lung tissue specimens from five recipients contained small numbers of the male gender version of the type II pneumocytes. The proportion of Y chromosome-containing pneumocytes was less than 1 percent.

They also found a statistically significant relationship between the number of Y chromosome-containing pneumocytes and the incidence of acute cellular rejection in the tissue, suggesting that stem cell repopulation might be stimulated by greater degrees of injury to the lung.

The possibility that the presence of male gender pneumocytes in female lungs might result from an earlier pregnancy with a male fetus cannot be ruled out, Zander said. However, the association between the number of those cells found in the lung tissue with damage from rejection makes that unlikely.

There was no sign of fusion between the bone marrow-derived cells and the donor pneumocytes, said Zander, who holds the Harvey S. Rosenberg, M.D., Chair in Pathology and Laboratory Medicine at the medical school and serves on the Council of the American Society of Investigative Pathology, a prestigious organization focused upon investigating mechanisms of disease. She also was awarded the Young Clinical Scientist Award this year by the Association of Clinical Scientists.

Study co-authors are Maher Baz and Christopher Cogle both of the Department of Medicine; Gary Visner of the Department of Pediatrics and senior author James Crawford, of the Department of Pathology, all at the University of Florida College of Medicine in Gainesville, Fla., and Neil Theise of the Department of Pathology

Scott Merville | EurekAlert!
Further information:
http://www.uth.tmc.edu

More articles from Life Sciences:

nachricht Enduring cold temperatures alters fat cell epigenetics
19.04.2018 | University of Tokyo

nachricht Full of hot air and proud of it
18.04.2018 | University of Pittsburgh

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

Im Focus: Basel researchers succeed in cultivating cartilage from stem cells

Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.

Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...

Im Focus: Like a wedge in a hinge

Researchers lay groundwork to tailor drugs for new targets in cancer therapy

In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...

Im Focus: The Future of Ultrafast Solid-State Physics

In an article that appears in the journal “Review of Modern Physics”, researchers at the Laboratory for Attosecond Physics (LAP) assess the current state of the field of ultrafast physics and consider its implications for future technologies.

Physicists can now control light in both time and space with hitherto unimagined precision. This is particularly true for the ability to generate ultrashort...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Diamond-like carbon is formed differently to what was believed -- machine learning enables development of new model

19.04.2018 | Materials Sciences

Electromagnetic wizardry: Wireless power transfer enhanced by backward signal

19.04.2018 | Physics and Astronomy

Ultrafast electron oscillation and dephasing monitored by attosecond light source

19.04.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>