Adipose tissue is recognized as an important cell-source for cell therapy since the discovery of adipose-derived stem cells (ADSC). ADSC represent an abundant and easily accessible source of mesenchymal stem cells, and are able to differentiate into a number of different cell types. However, obesity has previously shown not only to affect adipose tissue quantity but most importantly its quality. In the present study we used gene-expression microarrays to analyze the effect of obesity on ADSC gene expression.Methods
ADSC were harvested from subcutaneous white adipose tissue from 16 morbid obese (ADSCmo) and 8 non-obese (ADSCn) individuals. ADSC immunophenotype was evaluated, along with concomitant changes in gene expression using microarray technology and Partek analysis. Systems biology analysis was performed by IPA bioinformatics (Ingenuity Pathway Analysis).Results
ADSCmo and ADSCn strongly expressed typical ADSC surface antigens in the same proportion. Microarray analysis revealed that ADSCmo expressed genes clustered separately from ADSCn genes being obesity the major source of variation. Heat maps showed a clear differential transcript expression in the two ADSC sources. From the total number of genes analyzed, 607 genes were differentially expressed in ADSCmo and ADSCn (FDR < 6%). Function and network analysis of these transcripts suggested that cellular growth and proliferation (p < 0.005) and organism and tissue development (p < 0.005) were the most important functions affected by obesity. Moreover, most of the differential expressed genes seemed to be involved in the Aryl Hydrocarbon Receptor Signaling pathway (p=0.00001).Conclusion
Our data shows that obesity modifies the ADSC transcription of genes involved in cell growth, and in tissue and organism development.