Molecular muscle biology in vivo

Molecular muscle biology in vivo

2 -3master projects.


It is well known that muscle cells change upon training. Less well known are the molecular and cellular mechanisms involved.  We have attacked such biological problems from two angles. One is to unravel the molecular signalling pathways involved in coupling action potential activity in the muscle cell membrane to changes in gene transcription.  Similar mechanisms exist in the human brain, but muscles are easier to study. The other line of research is related to understand how muscle cell size is regulated. The muscle cells are the largest cells in the body, and their size is directly proportional to their strength.

There are several proteins that are expressed in fast and slow isoforms corresponding to fast and slow muscles. These are dependent on the specific pattern of activity delivered to the muscles from the central nervous system. We have focussed on helix-loop-helix molecules like myoD and myogenin that are both modified by activity. Also other pathways are investigated such as those connected to low oxygen levels in working muscles and to lipid metabolism. For the latter, the lipid sensor and transcription factor PPARd seems to be important, and has implications for understanding modern life style diseases such as metabolic syndrome. An example of this line of research is this recent paper

Our other line of research uses modern in vivo imaging techniques to study single cells in intact animals. The large cytoplasmic volumes of muscle cells are supported not by one but several hundred nuclei. The muscle cell size determines force, and strength training leads to muscle stem cells in the muscle multiplying and injecting their nuclei into the muscle fibres in order to increase the synthetic capacity for actin and myosin. It was previously believed that such extra nuclei were lost by apoptosis when exercise stops, but we have recently observed that they are permanent and this could explain why previously trained individuals are more easily re-trained, so called muscle memory. This observation has received considerable media attention since it has implications for practical training advice and for exclusion times after doping offences

A recent paper for this line of research is published here

Thesis work in our group gives training in molecular, physiological and microscopy imaging techniques. The details of the project will be discussed with the students. The group currently consists of 2 master students, 4 PhD students and 2 post docs. We can accept up to 3 new students.

 

Publisert 14. aug. 2017 11:29 - Sist endret 14. aug. 2017 11:29

Omfang (studiepoeng)

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