Disputation: Kenth-Arne Hansson
PhD candidate Kenth-Arne Hansson at the Department of Biosciences will be defending the thesis "The relationship between cell physiology and size studied in skeletal muscle fibers" for the degree of Philosophiae Doctor.
The disputation will be live streamed using Zoom. The host of the session will moderate the technicalities while the chair of the defence will moderate the disputation.
Ex auditorio questions: The chair of the defence will invite the audience to ask ex auditorio questions either written or oral. This can be requested by clicking "Participants" followed by clicking "Raise hand".
The meeting opens for participation just before 1.15 PM, and closes for new participants approximately 15 minutes after the defense has begun.
Mechanisms of sarcopenia and potential routes to its prevention
Main research findings
The muscle cells are by far the largest cells in the body, with volumes 100,000 times larger than for other cells. The largest muscle cells in humans can be more than 40 cm (15 inches) long, and while most cells contain only one nucleus with DNA, a muscle cell can contain more than 40,000 nuclei.
In his work, Kenth-Arne Hansson found, among other things, that even if the DNA-content increases by supplying new cell nuclei from stem cells in the tissue during growth, this does not keep pace with the increase in volume.
Therefore, when muscle cells grow during development, or due to strength training, the number of nuclei increases, but it does not keep pace with the increase in volume. Hence, the larger the cell become the less concentrated DNA products turn out to be and therefore limiting the size.
The findings of Hansson’s work strengthen the previous discovery of a so-called muscle memory, which seems to aid re-training when previous strength-exercise has led to a higher DNA content by acquiring permanent cell nuclei.
As a result of this doctoral work, Hansson and colleagues have shed new light into how the largest mammalian cell regulate cell size across species and developmental age.