Human Adipose Tissue Is a Source of Multipotent Stem Cells

TLDR

Adipose tissue, like bone marrow, harbors a mesenchymal stem cell–like population (PLA cells) that can be isolated from lipoaspirates and differentiate into osteogenic, adipogenic, myogenic, and chondrogenic lineages. The study aimed to confirm the presence of stem cells in adipose tissue by characterizing PLA cells and clones with molecular and biochemical assays. The authors isolated PLA cells and clonal subpopulations and evaluated them with molecular markers and biochemical assays. PLA cells displayed MSC‑like CD marker profiles, differentiated into mesodermal and neurogenic lineages with lineage‑specific gene and protein expression, and exhibited distinct CD marker and gene expression patterns compared to MSCs.

Abstract

Much of the work conducted on adult stem cells has focused on mesenchymal stem cells (MSCs) found within the bone marrow stroma. Adipose tissue, like bone marrow, is derived from the embryonic mesenchyme and contains a stroma that is easily isolated. Preliminary studies have recently identified a putative stem cell population within the adipose stromal compartment. This cell population, termed processed lipoaspirate (PLA) cells, can be isolated from human lipoaspirates and, like MSCs, differentiate toward the osteogenic, adipogenic, myogenic, and chondrogenic lineages. To confirm whether adipose tissue contains stem cells, the PLA population and multiple clonal isolates were analyzed using several molecular and biochemical approaches. PLA cells expressed multiple CD marker antigens similar to those observed on MSCs. Mesodermal lineage induction of PLA cells and clones resulted in the expression of multiple lineage-specific genes and proteins. Furthermore, biochemical analysis also confirmed lineage-specific activity. In addition to mesodermal capacity, PLA cells and clones differentiated into putative neurogenic cells, exhibiting a neuronal-like morphology and expressing several proteins consistent with the neuronal phenotype. Finally, PLA cells exhibited unique characteristics distinct from those seen in MSCs, including differences in CD marker profile and gene expression.