Navigation Links
Discarded immune cells induce the relocation of stem cells
Date:5/23/2013

Madrid, 23 May 2013.- CNIC researchers have discovered that the daily clearance of neutrophils from the body stimulates the release of hematopoietic stem cells from the bone marrow into the bloodstream, according to a report published today in the journal Cell.

Neutrophils are leukocytes (white blood cells) that defend the body against attack from bacteria and other disease organisms. To perform their function, these cells release toxic substances when they come into contact with microorganisms. However, release of these substances in the wrong place by damaged neutrophils can result in severe injury to blood vessels and tissues. Evolution appears to have resolved this conflict by ensuring that neutrophils are renewed much more rapidly than most other cells in the body: approximately 1011 neutrophils are eliminated every day and an equivalent number of stem cells are released into the bloodstream. This in turn generates a second problem: what to do with all these cells that have to be eliminated.

Dr. Andrs Hidalgo and his team in the Department of Epidemiology, Atherosclerosis and Cardiovascular Imaging, led by Dr. Valentn Fuster, have discovered the function of these neutrophils expelled every day by the body.

Graduate student Mara Casanova Acebes (Universidad Autnoma de Madrid), found that when additional apoptotic neutrophils were injected into mice, there was an increase in the number of circulating hematopoietic stem cells, the cells that generate all blood cells.

Using a wide variety of experimental approaches, including imaging assays, pharmacological treatments and genetic analysis, the team showed that when neutrophils in the blood get old, they migrate to the bone marrow to be eliminated by specialized phagocytotic cells called macrophages. The act of phagocytosing the neutrophils alters these macrophages' genetic properties and functions, and these changes in turn alter the function of specialized cells whose job it is to retain hematopoietic stem cells in the bone marrow. "As a consequence, the stem cells are released into the blood", explains Mara Casanova, first author of the study.

According to Dr. Hidalgo, "Key questions that arise from our study relate to the role of the hematopoietic stems cells expelled from the bone marrow, and how the elimination of neutrophils might affect other important stem cell populations, for example those that produce tumors".

The research also reveals that the aging of neutrophils follows a day/night, or circadian, cycle, suggesting possible implications for disease processesfor instance heart attackthat occur more frequently at certain times of day.

"Our study shows that stem cells are affected by day/night cycles thanks to this cell recycling. It is possible that the malign stem cells that cause cancer use this mechanism to relocate, for example during metastasis", Hidalgo emphasizes.

But this finding could have more direct implications for cardiovascular health. According to the authors, the daily changes in the function of neutrophils could be responsible for the tendency of acute cardiovascular and inflammatory events, such as heart attack, sepsis or stroke, to occur at certain times of day.

Dr. Hidalgo concludes, "Given that this new discovery describes fundamental processes in the body that were unknown before, it will now be possible to interpret the alterations to certain physiological patterns that occur in many diseases."


'/>"/>

Contact: Ainhoa Iriberri
airiberri@cnic.es
34-610-295-556
Centro Nacional de Investigaciones Cardiovasculares
Source:Eurekalert

Related medicine news :

1. How does the immune system fight off threats to the brain? New research yields fresh insight
2. Regulatory immune cell diversity tempers autoimmunity in rheumatoid arthritis
3. Mayo Clinic: Exhaustion renders immune cells less effective in cancer treatment
4. Rutgers team discovers novel approach to stimulate immune cells
5. Scientists study serious immune malfunction
6. Babies susceptibility to colds linked to immune response at birth
7. Reactions to HIV drug have autoimmune cause, reports AIDS journal
8. First study to suggest that the immune system may protect against Alzheimers changes in humans
9. Belly Membrane May Regulate Immune System, Mouse Study Finds
10. Moffitt researcher, colleagues find success with new immune approach to fighting some cancers
11. Researchers reveal crucial immune fighter role of the STING protein
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/25/2016)... ... May 25, 2016 , ... TransactRx announces the release ... of medical service claims by Pharmacy Benefit Managers that were submitted by Retail ... The TransactRx Cross Benefit Clearinghouse receives standard professional medical claims submitted from the ...
(Date:5/25/2016)... ... , ... America Walks , a national advocacy organization that promotes walking ... of Pittsburgh Graduate School of Public Health , has been awarded a Walking ... from around the country to participate in a four-month training program designed to strengthen ...
(Date:5/25/2016)... (PRWEB) , ... May 25, 2016 , ... ... health insurance, has seen a significant spike in their clients' employee participation for ... annual biometric health screening by implementing a high-deductible health plan with outcome-based deductible ...
(Date:5/25/2016)... ... May 25, 2016 , ... HealthPostures , a national ... leading engineers at the American Society of Safety Engineers Conference in Atlanta, Georgia. ... , Engineers, speakers and exhibitors from more than 40 countries are scheduled to ...
(Date:5/24/2016)... ... 2016 , ... Sterling Global Products is launching a Kickstarter campaign focused on ... dispenser. The campaign kick-off video is located via this link https://youtu.be/WsO4qz2odco . The ... is to raise $1,000 per day for a total of $25,000. The funds will ...
Breaking Medicine News(10 mins):
(Date:5/24/2016)... , May 24, 2016 ... médica para ayudar a los médicos a compartir sus ... pacientes a escala mundial. Profesionales médicos de Europa, África, ... se han apuntado a la aplicación, que combina la ... un entorno totalmente seguro. Educación   ...
(Date:5/24/2016)...   , Study met ... and superiority in , Excellent plus ... of the ascending colon   , ... B.V. today announced new positive data from the phase III MORA ... standard 2 litre PEG with ascorbate. The study met both primary ...
(Date:5/24/2016)... , May 24, 2016 ARANZ ... for the healthcare sector, has been named the Coretex Hi-Tech ... Awards 2016. Dr Bruce Davey , CEO ... our team.  It,s really good to be recognised for the ... Our products are used in 35 countries around the world ...
Breaking Medicine Technology: