Effect of tissue-harvesting site on yield of stem cells derived from adipose tissue: implications for cell-based therapies

TLDR

The stromal vascular fraction of adipose tissue contains abundant multipotent stem cells that can differentiate into mesodermal lineages, and harvesting them in a single surgical procedure would avoid costly in vitro expansion, but sufficient cell numbers are required. The study examined whether the anatomical site of adipose tissue harvest—abdomen versus hip/thigh—affects the yield and functional capacity of adipose‑derived stem cells. ASC frequency was quantified by limiting dilution and colony‑forming unit assays, and their chondrogenic and osteogenic differentiation potential was evaluated using qRT‑PCR and immunohistochemistry. ASCs from abdominal tissue were present at a significantly higher frequency (≈5.1 %) than those from hip/thigh (≈1.2 %), although total nucleated cell counts, CFU osteogenic potential, growth kinetics, phenotype, and differentiation capacity were comparable, indicating that the abdomen is the preferred site for one‑step stem‑cell therapies.

Abstract

The stromal vascular fraction (SVF) of adipose tissue contains an abundant population of multipotent adipose-tissue-derived stem cells (ASCs) that possess the capacity to differentiate into cells of the mesodermal lineage in vitro. For cell-based therapies, an advantageous approach would be to harvest these SVF cells and give them back to the patient within a single surgical procedure, thereby avoiding lengthy and costly in vitro culturing steps. However, this requires SVF-isolates to contain sufficient ASCs capable of differentiating into the desired cell lineage. We have investigated whether the yield and function of ASCs are affected by the anatomical sites most frequently used for harvesting adipose tissue: the abdomen and hip/thigh region. The frequency of ASCs in the SVF of adipose tissue from the abdomen and hip/thigh region was determined in limiting dilution and colony-forming unit (CFU) assays. The capacity of these ASCs to differentiate into the chondrogenic and osteogenic pathways was investigated by quantitative real-time polymerase chain reaction and (immuno)histochemistry. A significant difference (P = 0.0009) was seen in ASC frequency but not in the absolute number of nucleated cells between adipose tissue harvested from the abdomen (5.1 +/- 1.1%, mean +/- SEM) and hip/thigh region (1.2 +/- 0.7%). However, within the CFUs derived from both tissues, the frequency of CFUs having osteogenic differentiation potential was the same. When cultured, homogeneous cell populations were obtained with similar growth kinetics and phenotype. No differences were detected in differentiation capacity between ASCs from both tissue-harvesting sites. We conclude that the yield of ASCs, but not the total amount of nucleated cells per volume or the ASC proliferation and differentiation capacities, are dependent on the tissue-harvesting site. The abdomen seems to be preferable to the hip/thigh region for harvesting adipose tissue, in particular when considering SVF cells for stem-cell-based therapies in one-step surgical procedures for skeletal tissue engineering.