Navigation Links
Forgotten by evolution?

Not least because undifferentiated cells with features typical of stem cells are being increasingly found in organs like the liver, brain, and muscles, scientists are beginning to assume that these cells play a role in repairing organs. Researchers from the Max Planck Institute for Heart and Lung Research in Bad Nauheim, Germany have now demonstrated, in a study published in the journal Molecular and Cellular Biology, that at least some adult stem cells could be the mere remnants of former embryonal differentiation processes, or, in other words, "footprints" of evolution. (Molecular and Cellular Biology, November 2005)

The scientists belonging to Thomas Braun's working group used as a basis for their research two cell lines of mesenchymal stem cells which had been isolated from the bone marrow of mice. What was particularly special about the process they used was that they did not add growth factors to the culture medium; the goal was to prevent the cells from differentiating prematurely. By doing so, the scientists discovered that the two cell lines were different in the expression of typical stem cell markers. The researchers thus suspect that mesenchymal stem cells are a heterogeneous group of various, different cells, that have similar characteristics.

As was hoped, the scientists, using certain substances, were able to bring the stem cell line to express proteins characteristic of muscle cells. Interestingly, when a particular path, known as the wnt-signal path, was stimulated, the cells began to develop the features of heart muscle cells. In contrast, when they were beforehand stimulated with a protein known as CDO, the cells showed certain characteristics of skeleton muscle cells.

In both experiments, a row of muscle-specific genes was activated in the cells. This provided evidence for the beginnings of a differentiation process. But this process was only apparently halfway complete. So, for example, after the activation of the wnt-sign aling cascade, there was no typical striped pattern; this suggests incomplete development of the contractile apparatus. In addition, the expression of marker genes for cardiomyocytes, like the alpha-myosin-heavy-chain protein, could only be shown after the scientists performed what is known as epigenetic reprogramming (epigenetic reprogramming is a synonym for heritable modifications of the DNA others than alterations of the base sequence like DNA-methylation and changes of the chromatin).

In the differentiation toward skeleton musculature, the scientists indeed saw characteristic features of the skeletal muscle cells. It never came, however, to the point that true, multi-nucleate cells were created. The researchers were, on the other hand, able to consistently observe fusion between mesenchymal stem cells and skeletal muscle cells (see image).

The Max Planck researchers have two possible explanations for their results. On one hand, the stem cells could be missing some factor which is absolutely necessary for the complete differentiation into specialised cells and tissue. On the other hand, it could be the case that at least some of the known adult stem cell types are "only" the rudiments of earlier embryonal differentiation processes, or even dispersed leftovers from previous evolutionary stages. Indeed, these cells are still showing plasticity which is a characteristic of stem cells, but no direct physiological function can be deduced from it.



Related biology news :

1. Overbearing colored light may reveal a second mechanism by which birds interpret magnetic signals
2. Bacteria which sense the Earths magnetic field
3. Researchers reveal mystery of bacterial magnetism
4. Study to explore using magnets to correct sunken chest
5. Using nanomagnets to enhance medical imaging
6. Scientists ID molecular switch in liver that triggers harmful effects of saturated and trans fats
7. Source of molecular triggers in cutaneous T cell lymphoma identified
8. Plants, animals share molecular growth mechanisms
9. NYU researchers simulate molecular biological clock
10. Scientists reveal molecular secrets of the malaria parasite
11. Scientists identify molecular events that drive cell senescence
Post Your Comments:

(Date:11/10/2015)... Nov. 10, 2015  In this report, ... basis of product, type, application, disease indication, ... this report are consumables, services, software. The ... safety biomarkers, efficacy biomarkers, and validation biomarkers. ... are diagnostics development, drug discovery and development, ...
(Date:11/2/2015)... , Nov. 2, 2015  SRI International has ... to provide preclinical development services to the National Cancer ... SRI will provide scientific expertise, modern testing and support ... of preclinical pharmacology and toxicology studies to evaluate potential ... --> The PREVENT Cancer Drug Development Program is ...
(Date:10/29/2015)... 2015  Connected health pioneer, Joseph C. Kvedar ... technology-enabled health and wellness, and the business opportunities that ... The Internet of Healthy Things . Long before ... existed, Dr. Kvedar, vice president, Connected Health, Partners HealthCare, ... moving care from the hospital or doctor,s office into ...
Breaking Biology News(10 mins):
(Date:11/30/2015)... ... November 30, 2015 , ... ... tighter software integration with MarkLogic, the Enterprise NoSQL database platform provider, creating ... drive change. , Smartlogic’s Content Intelligence capabilities provide a robust set of ...
(Date:11/27/2015)... ... November 27, 2015 , ... Pittcon is pleased to announce ... offered in symposia, oral sessions, workshops, awards, and posters. The core of ... applications such as, but not limited to, biotechnology, biomedical, drug discovery, environmental, food ...
(Date:11/25/2015)... --> ... 2020 report analyzes that automating biobanking workflow will ... long-term samples, minimizing manual errors, improving the workflow ... errors such as mislabeling or inaccurate sample barcoding ... a vital role in blood fractionation, DNA extraction, ...
(Date:11/25/2015)... HOLLISTON, Mass. , Nov. 25, 2015 ... HART ), a biotechnology company developing bioengineered organ implants ... McGorry will present at the LD Micro "Main ... 2:30 p.m. PT. The presentation will be webcast live ... Management will also be available at the conference for ...
Breaking Biology Technology: