Introduction: Adhesion-based culture conditions have been the standard technique for in vitro expansion of ASCs. However, stem cells from different organs grow in suspension and display a more primordial phenotype characterized aggregation in clusters as spheroids. We hypothesized that S-ASCs could represent an upstream stage of the traditional adherent ASCs (aASCs) before they enter an early differentiation pathway leading to their adhesion. Molecular profiles of miRNAs and mRNAs were used between aASCs and S-ASCs to investigate our hypothesis. Methods: Lipoaspirate samples were processed for the extraction of S-ASCs as previously described by our lab. The miRNAs profile was analyzed using Taqman Array Human MiRNA A Cards in S-ASCs and aASCs cells. Statistically significant changes are considered up- or down-regulation of miRNA expression higher than 2 folds compared to control (p<0.001). Results: After a screening analysis of several miRNAs, we compared molecular patterns between S-ASCs with aASCs and the principal miRNAs and mRNAs involved with the stemness and mesenchymal differentiation. S-ASCs displayed significant up-regulation of miR-142-3p and SOX2, OCT4, NANOG, (5-fold increase) typically expressed in the pluripotent stem cells. Consequently, the early (SOX-9, RUNX-2, PPARg, miR-495, miR-221, miR-30c) and late (LPL, ALP, COL10A, miR-140, miR-143 and miR-100) RNAs correlated with mesenchymal differentiation was up-regulated in aASCs. Furthermore, we have assessed the same molecular analysis in S-ASCs and aASCs during different time in vitro culture up to 28 days. The results have demonstrated the maintenance of stemness only in S-ASCs, expressing high level of pluripotent stem cells markers and low level of differentiation markers. Conclusion: S-ASCs overexpress important pluripotent stem cells markers typical of iPS cells that are not present in aASCs. Furthermore, miRNAs and mRNAs typical of differentiated cells in multiple lineages were significantly under-expressed in S-ASCs while being over-expressed in aASCs. This molecular pattern supports the upstream nature and the stemness maintenance of S-ASCs and the down-stream and more differentiated precursor nature of aASCs. This data represents the first step in the recognition of S-ASCs as the true stem cell population within adipose tissue.
|Numero di pagine||1|
|Stato di pubblicazione||Published - 2017|