Update on the mechanisms of homing of adipose tissue-derived stem cells.

Adipose tissue-derived stem cells (ADSCs), which resemble bone marrow mesenchymal stromal cells (BMSCs), have shown great advantages and promise in the field of regenerative medicine. They can be readily harvested in large numbers with low donor-site morbidity. To date, a great number of preclinical and clinical studies have shown ADSCs' safety and efficacy in regenerative medicine. However, a better understanding of the mechanisms of homing of ADSCs is needed to advance the clinical utility of this therapy. In this review, the reports of the homing of ADSCs were searched using Pubmed and Google Scholar to update our knowledge. ADSCs were proved to interact with endothelial cells by expressing the similar integrins with BMSCs. In addition, ADSCs do not possess the dominant ligand for P-selectin, just like BMSCs. Stromal derived factor-1 (SDF-1)/CXCR4 and CXC ligand-5 (CXCL5)/CXCR2 interactions are the two main axes governing ADSCs extravasation from bone marrow vessels. Some more signaling pathways involved in migration of ADSCs have been investigated, including LPA/LPA1 signaling pathway, MAPK/Erk1/2 signaling pathway, RhoA/Rock signaling pathway and PDGF-BB/PDGFR-β signaling pathway. Status quo of a lack of intensive studies on the details of homing of ADSCs should be improved in the near future before clinical application.