Preadipocyte to adipocyte
|Series:||IN_VITRO DIFFERENTIATION SERIES|
|Species:||Human (Homo sapiens)|
|Link to TET:||FILE|
|Sample providers :||Peter Arner|
|Primary cells or cell line:||primary cells|
|Time span:||12 days|
|Number of time points:||3|
Adipose tissue can account for between 5% (lean athletes) and 60% (morbidly obese) of total body mass, making it one of the most plastic organs in the body . In response to changed nutritional status, both adipocyte cell number and size change and even under stable conditions as much as 10% of the adipocytes are turned over annually [1,2]. Thus the birth of new adipocytes from precursor cells (adipogenesis) is central for a functional fat tissue.
We are using two different models of human adipogenesis in the FANTOM5 study. Both originate from the stromal-vascular fraction (SVF) of human subcutaneous adipose tissue. The first model, here called preadipocytes, consists of cells differentiated in vitro directly after SVF isolation from adipose tissue. This means only later stages of differentiation can be monitored as samples in the beginning contain other cell types, like immune and endothelial cells, that contaminates the results. These contaminants die off after approximately 3-4 days. For this model we have taken tissue from four donors and sampled differentiation at time-points 4, 8 and 12 days after differentiation start. We have also isolated mature adipocytes from the adipose tissue of these donors. For the other model system, here called human adipose-derived mesenchymal stem cells (hASC), we have propagated cells from the SVF in vitro thus selecting for a stem cell/progenitor population. These cells can be expanded and cultured for several passages. This gives us cells with a homogenous genetic background and since contaminants are removed from the beginning, differentiation can be monitored from start to finish. Here we have collected triplicate samples at 0, 15, 30, 45 min, 1 h, 1 h 20 min, 1 h 40 min, 2 h, 2 h 30 min, 3 h, 12 h and 1, 2, 4, 8, 12 and 14 days after differentiation start.
A key aspect of adipocyte maturation is the accumulation of lipid in intracellular lipid droplets. The accumulation of lipids can be seen as morphological changes in the microscope at low magnification (10x) and can be further visualized using lipid stains such as bodipy (shown below for day 8 and 12).
Profiled time course samples