How do biochemical reactions take place in living cells?
“It is important to realise that up to about 10 years ago, cells – if you wanted to study them – were always dead,” says Frans Ramaekers, professor of molecular cell biology. “Tissues or cells was harvested, grounded or frozen. This meant that you only had snapshots and therefore missed important information. Although it is possible to put this information in a chronological sequence, this never gives you an accurate picture of the entire process.”
Much has improved over the last few years. Not only have new techniques been developed to stain molecules in living cells, also microscopes have become much better. “I can now follow a protein being transported in a cell or study more precisely the processes that take place during cell division. We film this and you can actually see the biochemical reactions taking place.”
By studying living cells, new discoveries are made, as Maastricht university lecturer Jos Broers recently did. He performs, amongst others, research into progeria, a rare syndrome in children, with symptoms suggestive of premature ageing. “We knew that these children had cell nucleus defects, but did not know exactly what happened,” says Ramaekers. Our research made clear that the cell nucleus regularly broke, but then closed again. “This happens very quickly, often in a matter of minutes, so if we only had snapshots, this would not have been visible. A kind of bulge appears in the nucleus. This opens, protein leaks from it, and then the nucleus closes again making it look normal.”
Despite all developments, the question ‘how do biochemical reactions take place in living cells’ remains a difficult one to answer. “There are so many. A single cell may contain more than 10 thousand different proteins,” says Ramaekers. “On the other hand, a lot of research is being done within this area and developments are being made at an increasing pace. This is a technology-driven field. Microscopes are getting better, and we aim at visualizing individual molecules. That is yet still very laborious, but things are moving in that direction. This will contribute significantly in finally answering this question.”
The Royal Netherlands Academy of Arts and Sciences (KNAW) made a list of the 50 most important research questions for the Netherlands. Every week a UM researcher gives an answer. This is the last part in this series.