Navigation Links
Key to aging immune system is discovered
Date:7/31/2014

There's a good reason people over 60 are not donor candidates for bone marrow transplantation. The immune system ages and weakens with time, making the elderly prone to life-threatening infection and other maladies, and a UC San Francisco research team now has discovered a reason why.

"We have found the cellular mechanism responsible for the inability of blood-forming cells to maintain blood production over time in an old organism, and have identified molecular defects that could be restored for rejuvenation therapies," said Emmanuelle Passegu, PhD, a professor of medicine and a member of the Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research at UCSF. Passegu, an expert on the stem cells that give rise to the blood and immune system, led a team that published the new findings online July 30, 2014 in the journal Nature.

Blood and immune cells are short-lived, and unlike most tissues, must be constantly replenished. The cells that must keep producing them throughout a lifetime are called "hematopoietic stem cells." Through cycles of cell division these stem cells preserve their own numbers and generate the daughter cells that give rise to replacement blood and immune cells. But the hematopoietic stem cells falter with age, because they lose the ability to replicate their DNA accurately and efficiently during cell division, Passegu's lab team determined.

Especially vulnerable to the breakdown, the researchers discovered in their new study of old mice, are transplanted, aging, blood-forming stem cells, which lack the ability to make B cells of the immune system. These B cells make antibodies to help us fight all sorts of microbial infections, including bacteria that cause pneumonia, a leading killer of the elderly.

In old blood-forming stem cells, the researchers found a scarcity of specific protein components needed to form a molecular machine called the mini-chromosome maintenance helicase, which unwinds double-stranded DNA so that the cell's genetic material can be duplicated and allocated to daughter cells later in cell division. In their study the stem cells were stressed by the loss of activity of this machine and as a result were at heightened risk for DNA damage and death when forced to divide.

The researchers discovered that even after the stress associated with DNA replication, surviving, non-dividing, resting, old stem cells retained molecular tags on DNA-wrapping histone proteins, a feature often associated with DNA damage. However, the researchers determined that these old survivors could repair induced DNA damage as efficiently as young stem cells.

"Old stem cells are not just sitting there with damaged DNA ready to develop cancer, as it has long been postulated" Passegu said.

But not all was well in the old, surviving stem cells. The molecular tags accumulated on genes needed to make the cellular factories known as ribosomes. The ribosomes make all the cell's proteins. Passegu will further explore the consequences of reduced protein production as part of her ongoing research.

"Everybody talks about healthier aging," Passegu added. "The decline of stem-cell function is a big part of age-related problems. Achieving longer lives relies in part on achieving a better understanding of why stem cells are not able to maintain optimal functioning."

Passegu hopes that it might be possible to prevent declining stem-cell populations by developing a drug to prevent the loss of the helicase components needed to faithfully unwind and replicate DNA, thereby avoiding immune-system failure.


'/>"/>

Contact: Jeffrey Norris
jeffrey.norris@ucsf.edu
415-502-6397
University of California - San Francisco
Source:Eurekalert  

Related biology technology :

1. Leveraging ‘Big Data’ - Methodological Considerations in Health Services Research, New Webinar Hosted by Xtalks
2. Fastec Imaging Introduces the First High Speed Camcorder
3. Introducing a New Bonus Treatment Cup for EvoDerma’s NOOME Anti-Aging Motion
4. Aging Population & Rising Incidence of Chronic Diseases to Drive the Global Mesenchymal Stem Cells Market, According to New Report by Global Industry Analysts, Inc.
5. Latest Technologies for Life-saving Applications on the Program at SPIE Medical Imaging
6. Studies Show Pterostilbene Shows Promise for Anti-Aging and Maintaining Healthy Brain
7. Founders Fund Backs Nanotronics Imaging
8. The Houston Methodist Human Performance Lab Launches Innovative Study on Triathletes, Investigating the Effects of Aging and Training Variables on Triathlon Performance
9. Smart Imaging Technologies and InvitroCue Team Up to Bring Digital Pathology to Asia
10. New venue, new conference, new courses, new technologies for Electronic Imaging 2014
11. Scientists accelerate aging in stem cells to study age-related diseases like Parkinsons
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Key to aging immune system is discovered
(Date:10/11/2017)... ... 11, 2017 , ... The CRISPR-Cas9 system has ... and avoiding the use of exogenous expression plasmids. The simplicity of programming this ... gain-of-function studies. , This complement to loss-of-function studies, such as with RNAi ...
(Date:10/11/2017)... and LAGUNA HILLS, Calif. , Oct. 11, ... Research, London (ICR) and University of ... SkylineDx,s prognostic tool to risk-stratify patients with multiple myeloma (MM), ... nine . The University of Leeds ... funded by Myeloma UK, and ICR will perform the testing ...
(Date:10/10/2017)... ... October 10, 2017 , ... ... targeted antibody-drug conjugate (ADC) therapeutics, today confirmed licensing rights that give it ... Nanoparticle), a technology developed in collaboration with Children’s Hospital Los Angeles (CHLA). ...
(Date:10/10/2017)... ... October 10, 2017 , ... USDM Life Sciences , ... life sciences and healthcare industries, announces a presentation by Subbu Viswanathan and Jennifer ... “Automating GxP Validation for Agile Cloud Platforms,” will present a revolutionary approach to ...
Breaking Biology Technology:
(Date:4/19/2017)... New York , April 19, 2017 ... competitive, as its vendor landscape is marked by the ... the market is however held by five major players ... Safran. Together these companies accounted for nearly 61% of ... of the leading companies in the global military biometrics ...
(Date:4/13/2017)... PUNE, India , April 13, 2017 According ... Identity Proofing, Identity Authentication, Identity Analytics, Identity Administration, and Authorization), Service, Authentication ... by MarketsandMarkets™, the IAM Market is expected to grow from USD 14.30 ... Annual Growth Rate (CAGR) of 17.3%. ... ...
(Date:4/11/2017)... 11, 2017 NXT-ID, Inc. (NASDAQ:   ... announces the appointment of independent Directors Mr. Robin D. ... Board of Directors, furthering the company,s corporate governance and expertise. ... Gino Pereira , ... forward to their guidance and benefiting from their considerable expertise ...
Breaking Biology News(10 mins):