LAUSR

BACKGROUND Adipose-derived mesenchymalstromal cells (ASC) are currently tested in regenerative medicine to promote tissue reconstruction after injury. Regardingautologous purpose, the possible loss of therapeutic function and cell properties during aging have been questioned in adults. To date no reliable information is available concerning ASC from pediatric patients and a better knowledge is required for clinical applications. METHODS Subcutaneous adipose tissue was collected from 27 donors (0-1 years old) and 50 donors (1-12 years old) and compared with adult ASC for in vitro characteristics. ASC were then tested in a mouse model of limb ischemia. RESULTS Cells from the stromal vascular fraction (SVF) and subsequent cultured ASC were prepared. Only a greater amount in SVF cell number and ASC proliferative rate were found. Cell phenotype, colony formingunit-fibroblast (CFU-F) content, immunomodulation effect and adipogenic, osteoblastic and angiogenic potentials were not significantly different. In vivo, pediatric ASC induced an increase in microangiographic score in a mouse model of limb ischemia, even though improvement in vascular density was not significantly correlated to limb rescue. Finally messengerRNA (mRNA) analysis using a microarray approach identified that only 305 genes were differentially expressed (217 down- and 88 up-regulated) in pediatric versus adult ASC, confirming that ASC from both age groups shared very close intrinsic properties. CONCLUSION This is the first study reporting a comparative analysis of ASC from a large number of donors and showing that their in vitro and in vivo properties were similar and maintained during aging.