Cell proliferation limit and senescence (ES and fibroblasts)

[alexia29]

Homework Statement

Hello,
I am trying to understand the importance of proliferation limits and cell senescence. In particular, one of my homework questions is asking to compare the proliferation limit of Embryonic Stem cells (ES) and fibroblasts (which would be trans-differentiated) and describe how this difference plays a role when thinking about engineering organs, for example a heart transplant.

Homework Equations

Hayflick limit for senescence is ~50 cell divisions.

The Attempt at a Solution

Here is what I am thinking, however I am not sure if this is correct or not.
Non-differentiated the ES cells can divide almost indefinitely, however when the stem cell differentiates into a specific function, it goes through approximately 50 cell divisions before senescence. On the other hand, fibroblasts have already gone through some cell divisions at the point when they are trans-differentiated. Therefore, their life before senescence is less than 50 cell divisions.

Can someone verify this? How do ES cells and fibroblasts compare with regards to the Hayflick limit?
Thank you.

 

[Asim Riaz]

Yes, this is correct. Embryonic stem cells can divide almost indefinitely in their undifferentiated state, while fibroblasts have already gone through some cell divisions before they are trans-differentiated and therefore have a shorter life before senescence. The Hayflick limit for both ES cells and fibroblasts is approximately 50 cell divisions. This difference plays an important role when it comes to engineering organs such as a heart transplant. For example, since ES cells have a much longer life before senescence, they can be used to produce more cells necessary for a successful transplant. On the other hand, fibroblasts have a shorter life before senescence, so they may not be able to produce as many cells as ES cells.