Reference Gene Expression in Adipose-Derived Stromal Cells Undergoing Adipogenic Differentiation

Adipose-derived stromal cells (ASCs) are becoming increasingly attractive as cellular therapy products. Their differentiation potential, the secretion of growth and differentiation factors, and the ability to cryopreserve the cells over extended periods are important features. Changes in experimental conditions result in changes in gene expression, and reverse-transcription quantitative polymerase chain reaction (RT-qPCR) has become an important tool for measuring these changes. There is, however, the potential to introduce technical bias in the process, which can be diminished through the selection of stable reference genes (RGs). Using geNorm software, in this in vitro study we explore the effects that adipogenic differentiation for a 21 day induction period, cryopreservation (freshly isolated ASCs or previously cryopreserved/frozen ASCs), and culture medium supplementation (fetal bovine serum vs. pooled human platelet lysate) have on the stability of 11 RGs. We found that RG stability is markedly affected by the different experimental conditions. Of the RGs assessed, YWHAZ, HPRT, TBP, and ACTB were stably expressed genes under all experimental conditions. We recommend that a panel of stable RGs should be selected before studying gene expression during adipogenesis, and that this is based on the experimental condition(s) being investigated. IMPACT STATEMENT: As the use of adipose-derived stromal cells (ASCs) in clinical trials increases, so does the amount of experimental data from research groups, many of which use human ASCs to study adipogenesis in obesity. Different conditions are constantly being applied to ASCs in vitro, to obtain a therapeutic product for potential downstream applications. Few articles have looked at the effect of different conditions on ASC reference gene (RG) expression and stability, which was the aim of this research, as such this article will assist other researchers to make an informed decision about RG selection for gene expression studies using ASCs including those for adipogenesis.