Fate of adipose derived stem cells is correalted with expression of specific set of genes

Abstract

Purpose: Adipose tissue represents an abundant, accessible and rich source of adult stem cells with the ability to differentiate into multiple lineages. Our understanding of the dynamic process requiring indispensable differentiation of adipose-derived stem cells (ASCs) remains limited. Here, we describe that differentiation of ASCs into adipogenic, osteogenic, and chondrogenic lineages is dependent on expression of certain specific genes. Methods: ASCs were isolated from human adipose tissue by enzymatic digestion using collagenase. Isolated ASCs were cultured as monolayer in DMEM low-glucose medium supplemented with 10% fetal bovine serum (FBS) and 1% penicillin/streptomycin (P/S) at 37°C in a 5% CO2 incubator. Adipogenic differentiation of ASCs was done for 14 days using adipogenic medium. Osteogenic and chondrogenic differentiation of ASCs was done for 21 days using osteogenic and chondrogenic differentiation medium. Adipogenic differentiation of ASCs was accessed by Oil Red O staining, and gene expression of adipogenic markers. Osteogenic differentiation was accessed by Von Kossa staining, calcium estimation and gene expression of osteogenic markers. Chondrogenic differentiation was accessed by Alcian blue staining, and gene expression of chondrogenic markers. Results: Normal differentiation of ASCs into adipogenic lineage resulted in higher level of oil red o staining which represents higher adipose depots. The mRNA expression of adipogenic markers Adiponectin, FABP4, and PPAR-γ significantly increases with adipogenic differentiation. Interestingly, expression of TAZ decreases with adipogenic differentiation of ASCs. Differentiation of ASCs into osteogenic lineage resulted in higher amount of von Kossa staining along with significantly higher level of calcium concentrations. The mRNA expression of osteogenic markers RUNX2, Osteonectin, Osteopontin, ALP, and TAZ significantly increases during osteogenic differentiation. Differentiation of ASCs into chondrogenic lineage resulted in higher level of Alcian blue staining. The mRNA expression of chondrogenic markers Aggrecan, COL2A1, SOX9, and TAZ significantly increases during chondrogenic differentiation. Conclusions: We demonstrate that differential gene expression has critical role in ASCs lineage determination. By identifying and modulating expression of such genes, we may direct the differentiation fate of ASCs that will be useful as a cell therapy for regenerative medicine.