Cookie Settings

We use cookies to optimize our website. These include cookies that are necessary for the operation of the site, as well as those that are only used for anonymous statistic. You can decide for yourself which categories you want to allow. Further information can be found in our data privacy protection .

Essential

These cookies are necessary to run the core functionalities of this website and cannot be disabled.

Name Webedition CMS
Purpose This cookie is required by the CMS (Content Management System) Webedition for the system to function correctly. Typically, this cookie is deleted when the browser is closed.
Name econda
Purpose Session cookie emos_jcsid for the web analysis software econda. This runs in the “anonymized measurement” mode. There is no personal reference. As soon as the user leaves the site, tracking is ended and all data in the browser are automatically deleted.
Statistics

These cookies help us understand how visitors interact with our website by collecting and analyzing information anonymously. Depending on the tool, one or more cookies are set by the provider.

Name econda
Purpose Statistics
External media

Content from external media platforms is blocked by default. If cookies from external media are accepted, access to this content no longer requires manual consent.

Name YouTube
Purpose Show YouTube content
Name Twitter
Purpose activate Twitter Feeds

Blood stem cells: not in charge in an emergency!

No. 02 | 17/01/2023 | by Koh

After infections or blood loss, the body must compensate for the loss of blood cells as quickly as possible. This has long been considered the task of the hematopoietic stem cells in the bone marrow. But scientists at the German Cancer Research Center (DKFZ) have now discovered in mice that a certain population of progenitor cells takes over this task: This accelerates the regeneration of the blood cells and possibly protects the stem cells from exhaustion.

It is not the blood stem cells in the bone marrow, but multipotent progenitor cells that provide the replacement of mature blood cells after blood loss.
© Adobe Stock

As long as we are healthy, our body keeps the number of blood and immune cells largely constant. However, any infection or other disorder that increases cell consumption results in cell loss, which must be replaced as quickly as possible to keep the immune system fully functional.

During embryonic development, blood stem cells in the bone marrow give rise to all types of mature blood cells. "Therefore, it has long been presumed that the loss of blood and immune cells in emergency situations is signaled to the blood stem cells, which are stimulated to divide much faster than usual to immediately provide replacement," says Hans-Reimer Rodewald of DKFZ.

Blood stem cells can divide into a daughter cell, which remains a stem cell, and a second daughter cell, which continues to develop. These developing daughter cells first give rise to so-called multipotent progenitor cells, which are capable of differenciate into any type of blood cell. "Until now, we didn't know exactly whether it is actually the blood stem cells that provide regeneration in an emergency - or whether the progenitor cells take over this job," explains immunologist Katrin Busch, one of the first authors of the current paper.

Rodewald's team, in collaboration with Thomas Höfer's research group, also at DKFZ, has now been able to investigate this question in mice. To this end, the researchers used genetic markers that were incorporated into the blood stem cells and that can be traced through all further developmental steps in their cell progeny.

If the mice were infected with bacteria, they developed a systemic inflammation. As expected, the labeled blood stem cells reacted with cell division – which, however, did not result in an increased number of differentiated blood cells. In addition, the stem cells intensified transcription, but this primarily affected those genes that are associated with their self-renewal. Thus, the blood stem cells themselves are apparently not in charge of replenishing mature blood cells. This was true not only for bacterial infections, but also for other stressful health conditions such as anemia or a deficiency of various types of immune cells.

However, the situation was quite different when the population of multipotent progenitor cells was equipped with the genetic marker: After about eleven days, the number of different labeled white blood cells that emerged from the multipotent progenitor cells increased significantly in the bacterially infected mice.

"Having the progenitor cells do this task has several advantages: It speeds up the process, because differentiation from stem cells is a fairly slow process. In addition, there are significantly more progenitor cells than stem cells - this also helps to ensure that sufficient mature blood cells are available quickly," explains Höfer. Rodewald adds: "We also interpret the result as a possible protective mechanism of the blood stem cells, perhaps in order to avoid being exhausted by recurrent infections in the course of life."

Few years ago, scientists from Rodewald's and Höfer's lab had already demonstrated that, contrary to common expert opinion, pluripotent progenitor cells also play the major role in maintaining the number of blood cells under normal healthy conditions.

Ann-Kathrin Fanti, Katrin Busch, Alessandro Greco, Xi Wang, Branko Cirovic, Fuwei Shang, Tamar Nizharadze, Larissa Frank, Melania Barile, Thorsten Feyerabend, Thomas Hofer, and Hans-Reimer Rodewald: Flt3- and Tie2-Cre tracing identifies regeneration in sepsis from multipotent progenitors but not hematopoietic stem cells.
Cell Stem Cell 2023, DOI: https://doi.org/10.1016/j.stem.2022.12.014

The German Cancer Research Center (Deutsches Krebsforschungszentrum, DKFZ) with its more than 3,000 employees is the largest biomedical research institution in Germany. More than 1,300 scientists at the DKFZ investigate how cancer develops, identify cancer risk factors and search for new strategies to prevent people from developing cancer. They are developing new methods to diagnose tumors more precisely and treat cancer patients more successfully. The DKFZ's Cancer Information Service (KID) provides patients, interested citizens and experts with individual answers to all questions on cancer.

Jointly with partners from the university hospitals, the DKFZ operates the National Center for Tumor Diseases (NCT) in Heidelberg and Dresden, and the Hopp Children's Cancer Center KiTZ in Heidelberg. In the German Consortium for Translational Cancer Research (DKTK), one of the six German Centers for Health Research, the DKFZ maintains translational centers at seven university partner locations. NCT and DKTK sites combine excellent university medicine with the high-profile research of the DKFZ. They contribute to the endeavor of transferring promising approaches from cancer research to the clinic and thus improving the chances of cancer patients.

The DKFZ is 90 percent financed by the Federal Ministry of Education and Research and 10 percent by the state of Baden-Württemberg. The DKFZ is a member of the Helmholtz Association of German Research Centers.

RSS-Feed

Subscribe to our RSS-Feed.

to top
powered by webEdition CMS