I couldn't find a sufficiently detailed resource. This may be a very simple question for the social environment. These cells when I isolate cells from a particular tissue; Could it be from differentiated cells to not be divided? In primary cell cultures, I think we should do the same as the cell environment (like in the tissue environment's inducer factors). So if we select quiescence cells we can induce them for proliferate even if they are differantiated cells, but this is different environment. How can we sure from results of the experiments as if in vivo.
Hi Oguzahan, terminally differentiated cells isolated from tissues are often difficult to grow.
There is a Catch-22 in trying to make them proliferate. You can make them proliferate, but then they will not have the normal non-proliferating phenotype that you isolated.
Hi Oguzahan,
First of all quiescent state is not same with (terminally) differentiated state. In fact, I think quiescent cells are usually stem/progenitor cells (thus, ready for proliferation, but just cell cycle arrested) that acts as stem cell reserve and are important to maintain cellular homeostasis after injury.
The best example of quiescent cell culture would be satellite cells from skeletal muscle. When isolated during quiescent state it would exhibit phenotype Pax7+ and MyoD-, but when it is activated by bFGF it will become Pax7+ and MyoD+. You can keep it non-proliferating in culture by culturing in low serum condition (2% horse serum) without bFGF; however, due to rare population of these cells I think it will be very difficult to do experiment on them without expansion.
One needs to differentiate between "quiescence" and "terminally differentiated". In the first case, cells keep the proliferation potential and need a "stimulus" to enter the cell cycle to proliferate (divide). In the later case, the cells do not enter the cell cycle (therefore, unable to divide or proliferate). Cells can increase in size (therefore "grow" in size) in culture irrespective their status in the cell cycle.
Hi Oguzahan,
If you're not satisfied enough with a few general explanations to your request, please take a glance at the model utilized by a French team of Inserm, Créteil, France. While speaking with them recently, I got they were on the edge of publishing the data on adult skeletal muscle stem cells using CDKN1c (p57kip2), a cyclin-dependent kinase inhibitor. They showed that CDKN1c was not expressed in quiescent MuSCs, while being induced in activated and proliferating myoblasts and maintained in differentiating myogenic cells. However, while studying dynamic CDKN1c expression in adult myogenesis, they found what you are interested in. In particular, analyzing the expression of CDKN1c during MuSC-mediated myogenesis, single myofibers with their associated PAX7+ MuSCs from EDL muscles of adult wild-type mice were isolated. Immunostaining experiments, using a CDKN1c-specific antibody, showed that quiescent MuSCs were not labeled. To evaluate the kinetics of CDKN1c expression during activation, self-renewal, and differentiation, they analyzed myofibers that were cultured from 24 to 72 hr. Activated PAX7+ and MYOD+ myoblasts at T24-T48 presented with increasing amounts of CDKN1c. Unexpectedly, this negative cell cycle regulator was not expressed in the quiescent population, but in activated MuSCs entering the cell cycle. However, during this early proliferation phase, CDKN1c was restricted to the cytoplasm, - at a time point when most cells are in a proliferative state.
Best wishes,
Ilya
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