Mathematical Models of Adipose Tissue Dynamics - The Mechanobiology of Obesity and Related Diseases - page 12

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25 50 75 100 125

Cell diameter ( µ m)

Fig. 1 Bimodal size distribution of adipose cells. Adipose cells from epididymal fat depots in
C56BL/6 mice (male and 3 months old) were isolated, and relative frequencies of their diameters
were measured by a Coulter multi-sizer. Mean SD (n = 6)

preadipocytes and mature adipose cells. The exponential part consisting of small
cells may represent new cells recruited from progenitor cells, while the Gaussian
part may represent larger mature cells that have grown from the small ones. A
hypothetical dynamic model for the bimodal distribution will be discussed later. On
the other hand, Soula et al. [ 13 ] have recently proposed that the origin of the
bimodality is a singularity in the size-dependent growth rate of adipose cells. The
cell growth rate results from the balance between lipogenesis and lipolysis, both of
which depend on adipose cell size. The size-dependent growth rate has an unstable
singular size at the nadir size of the bimodal distribution. Therefore, cells below this
critical size shrink to smaller sizes while those above it can grow to larger sizes.
Another perspective from the viewpoint of stochastic modeling of adipogenesis in
cell culture can be found in [ 14 , 15 ], taking into account the accumulation and
formation of lipid droplets within adipocytes.

3 Bayesian Inference

As discussed above, the adipose tissue dynamics is intricate and requires further
investigation. However, current experimental techniques are not capable of
monitoring such changes in real time. Nevertheless, precise measurements of