Heinrich Leonhardt: Deciphering the epigenetic codes
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- One of the pioneers of epigenetics in Germany: Heinrich Leonhardt investigates how the reading of genes in cells is controlled by chemical modifications. Source: LMU
15.09.2010 -
There is no escaping our genes. This is where our genetic information is stored, and where information must be properly read-off during differentiation of the body’s cells. Professor Heinrich Leonhardt is investigating these reading mechanisms at the Ludwig Maximilians University in Munich. Epigenetics is a young field of research that is occupied with the information level above (greek=epi) DNA sequences, and Leonhardt takes the approach that many diseases can be explained by epigenetic malfunctions.
“The same information is created in each cell,” says Leonhardt, “This means that the genetic blueprint of cells is always the same.” And yet, a liver cell can routinely be differentiated from a hair cell. “And that's where epigenetics comes in, because it controls which parts of the genetic blueprint can actually be read off,” says the biochemist. “After the duplication of the DNA, individual genes that are not required in this particular cell are shut down. “Leonhardt examines in detail how these mechanisms actually function, and has developed new methods for looking inside living cells, for example with high-resolution light microscopy.
First insights into epigenetics in the 90s
During his PhD studies at the Max Planck Institute for Molecular Genetics in Berlin, Heinrich Leonhardt was present at a talk given by Tim Bestor, a researcher from the Harvard Medical School: Bestor had only recently isolated the first enzyme that was known to be involved in the reading-off process. This so-called DNA methyltransferase marks genes that should not be read off in a particular cell. “It quickly became clear this enzyme could not be the only one controlling this process of DNA methylation,” remembers Leonhardt. The interest of the young German researcher was aroused, and immediately after his graduation he began work in Bestor’s laboratory in Boston. “This was one of the best decisions of my life,” says Leonhardt today.
But when Leonhardt returned to Germany, he had to endure something of a dry spell in the field: In his first positions in clinical research, few believed in the medical relevance of the findings of epigenetics, he says. Today, things look markedly different. Leonhardt still undertakes basic research – since 2002 in Munich – but with a decidedly more application-oriented approach: “Many diseases cannot be explained through the genetic blueprint alone,” says Leonhardt. “We know, for example, that tumor formation can result if DNA methylation is disturbed.” In one of his current research projects, he is investigating the potential role of a malfunctioning DNA reading-off process in leukaemia. “If we find the malfunction, we could develop targeted epigenetic cancer therapies.”
Epigenetic code vulnerable to external influences
Like DNA, the epigenetic information is copied during cell division, but in contrast to DNA, methylation is more susceptible to external influences. “Stress over longer periods may well result in epigenetic changes,” says Leonhardt. The 49-year-old is still one of the few pioneers in his field in Germany, and gives regular lectures, also to lay audiences. He is often posed the question of whether negative epigenetic changes could possibly be inherited. “Aside from a few special cases, no!” says Leonhardt: Nutrition, stress, a sporty lifestyle – all these things may well be reflected in the respective cells, but we can not pass on acquired characteristics such as a toned or muscular body to our descendants. This could be bad news for some, a relief for others. Our sins are as unlikely as our virtues to be passed on to our children.
Author: Ute Zauft
