Helmholtz Association

DNA Methylation controls Blood Cell Decisions

In vitro kultivierte blutbildende Zellen der Maus. Foto: MDC/S. Ghani
In vitro cultivated hematopoietic cells of a mouse. Photo: MDC/S. Ghani

Blood cells live only a limited time. Therefore, the body perpetually creates new blood cells. Their reservoir is constituted by the blood stem cells. Depending on a chemical process long known to researchers, a blood stem cell either turns out to be a stem cell again after cell division or various blood cells develop. Now, a research group led by Dr. Frank Rosenbauer of the MDC has discovered that the level of DNA methylation also controls cell fate decision.

During methylation, methyl groups connect with the DNA. Their distribution on the DNA determines which genes are copied and which are blocked. DNA methylation is of great interest to researchers, since it can be influenced – in contrast to genetic information from environmental factors such as diet. Enzymes (methyltransferases) regulate the process.

“For instance, if the enzyme Dnmt1 is missing, the blood stem cells are defect and the affected mice die”, explains Rosenbauer. When blood stem cells produce some Dnmt1, they survive, but the stem cells lose thei,r potential for self-renewal, and only certain blood cells are created.

Cancer stem cells likewise hardly renew themselves when DNA methylation is very low. In this case, they then also develop less well into leukaemia cells. The MDC researchers now intend to find out why cancer stem cells can be inactivated by a Dnmt1 blockage.

Einblicke in die Forschung: Gesundheit

Listeria monocytogenes können menschliche Darmzellen befallen und dort schwere Infektionen auslösen. Foto: HZI/M. Rohde

How do pathogenic agents actually manage to overcome the defence barriers of the human body and attack the organism? The team around Professor Dr. Dirk Heinz at the Department of Structural Biology of the HZI pursues this question.

To 'Connecting Structural Biology and Wound Healing'

Einblicke in die Forschung: Gesundheit

With Salmonellae Against Cancer

Salmonellae are bacterial pathogenic agents that rapidly proliferate in insufficiently cooked egg dishes in warm weather causing commonly known and infamous consequences. Less known, but no less interesting, is the fact that in addition to ice-cream and egg dishes salmonellae also interact with tumour tissue.

To 'With Salmonellae Against Cancer'

Einblicke in die Forschung: Gesundheit

On the Path towards an individualised Cancer Therapy

The genome is the genetic material stored within the nucleus of every cell, consisting of a sequence of 3.2 billion DNA building blocks. In 2003, an international research team delivered the completely decoded human genome and thus completed the work on the human genome project begun in 1990. Now, German researchers have joined a new mammoth project of biomedical genome research.

To 'On the Path towards an individualised Cancer Therapy'

Einblicke in die Forschung: Gesundheit

Metabolomics – Key Tool for Diabetes Research

The risk for diabetes or other metabolic diseases increases enormously, when unhealthy eating habits and a lack of exercise coincide with genetic disposition. Researchers of Helmholtz Zentrum München discovered variants of known diabetes risk genes and other genes, which for the first time they could definitely link with lipometabolism disorders.

To 'Metabolomics – Key Tool for Diabetes Research'

Einblicke in die Forschung: Gesundheit

Brown Body Fat as a Weight Loss Product

Usually, metabolic regulation ensures energy balance so that the body weight remains fairly stable. In the event of increasing obesity, more energy is deposited in the so-called white adipose tissue than is used. By contrast, brown adipose tissue has a different function, converting energy into heat. The idea is, therefore, that brown adipose tissue could possibly help to restore the disturbed balance between absorption and consumption of energy.

To 'Brown Body Fat as a Weight Loss Product'

Einblicke in die Forschung: Gesundheit

Mouse as a Model for Stroke Patients

Some 250,000 people per year in Germany sustain a stroke. The majority of people affected then suffer from consequential damages such as paralysis and language or vision disorders. In collaboration with French colleagues, researchers
led by Professor Dr. Norbert Hübner of the MDC have now developed a mouse model enabling the detailed study of risk factors for stroke development.

To 'Mouse as a Model for Stroke Patients'

Einblicke in die Forschung: Gesundheit

Ultrafine Particles Aggravate Asthma

Exposure to particulate matter often leads to aggravation of allergic asthma. This association has already been established by epidemiological studies. However, Dr. Francesca Alessandriniand her colleagues from Helmholtz Zentrum München and from the Centre of Allergy & Environment (ZAUM) at Technische Universität  München wanted to investigate the role of ultrafine particles more exactly.

To 'Ultrafine Particles Aggravate Asthma'

Einblicke in die Forschung: Gesundheit

Time Lapsed Aging

As life expectancy increases more individuals retain good health lfor a longer time. However, also the risk of cancer, cardiovascular and neurodegenerative diseases increases with age. Today, neurodegenerative diseases take a significant toll as cause of death in old age. In Germany around one million individuals are affected by dementia.

To 'Time Lapsed Aging'

Einblicke in die Forschung: Gesundheit

Early Warning System for Neurodegenerative Diseases

When they have trouble remembering something, many older people ask themselves whether it is just old age making them a little forgetful, or whether it is a sign of the onset of dementia. Medical imaging technology such as magnetic resonance imaging (MRI), which visualises structural or molecular changes in the brain, can diagnose the causes behind such memory blips – but a negative result can give patients a false sense of security, as not all changes can be detected.

To 'Early Warning System for Neurodegenerative Diseases'

09.01.2013