These human adipose-derived stem cells (HADSC) exhibit pre-adipocyte characteristics, can be induced to differentiate into adipocytes. Many studies have demonstrated that cultured stem cells under altered gravity conditions modulate their proliferation and differentiation

Previously we reported that pre-adipocytes like 3T3L1 cells, also are used as model for basic studies on adipogenesis, submitted to the modelled gravity (RPM) in comparison to the cells grown in normal gravity, show a smaller number of differentiated cells and they accumulate less lipids. Moreover the expression of the differerentiation markers C/EBPa, PPARg and GLUT4 was reduced.

In this study we analyzed the effect of modelled microgravity with respect to normal gravity, on HADSC differentiation.

The differentiation process was analyzed at different stages evaluating:

• morphological changes through the analysis of the appearance of lipid droplets

• biochemical changes by quantitative estimate of lipids and insulin stimulated glucose uptake.

• molecular changes by evaluating the expression of the most important differentiation markers (C/ EBP/b C / EBPa, PPARg GLUT4, actin, tubulin).

Our preliminary results indicate that as the 3T3, HADSC also were affected by RPM. The expression of differentiation markers was differently modulated in RPM and this involves changes in morphological and biochemical properties of the differentiated cells.