Immunomodulatory and Antioxidative potentials of adipose-derived Mesenchymal stem cells isolated from breast versus abdominal tissue: a comparative study

Abstract

Background: Adipose-derived stem cells (ASCs) are considered ideal candidates for both research and cellular therapy due to ease of access, large yield, feasibility, and efficacy in preclinical and clinical studies. Unlike the subcutaneous abdominal fat depot, breast ASCs features are still not well recognized, limiting their possible therapeutic use. ASCs were found to exert immunomodulatory and antioxidative activities for maintaining homeostasis and functionality of diseased/damaged tissues. This study aims to investigate the immunomodulatory and antioxidative potentials of breast versus abdominal isolated ASCs to find out which anatomical site provides ASCs with better immunoregulatory and oxidative stress resistance capabilities.

Methods: ASCs were isolated from abdominal and breast tissues. Gene expression analysis was conducted for a panel of immunomodulatory and antioxidative genes, as well as adipokines and proliferation genes. Flow cytometric analysis of a group of immunomodulatory surface proteins was also performed. Finally, the significantly expressed genes have undergone protein-protein interaction and functional enrichment in silico analyses.

Results: Our results revealed similar morphological and phenotypic characteristics for both breast and abdominal ASCs. However, a significant elevation in the expression of two potent immunosuppressive genes, IL-10 and IDO as well as the expression of the multifaceted immunomodulatory adipokine, visfatin, was detected in breast versus abdominal ASCs. Moreover, a significant overexpression of the antioxidative genes, GPX1, SIRT5, and STAT3 and the proliferation marker, Ki67, was also observed in breast ASCs relative to abdominal ones. In silico analysis showed that both of the differentially upregulated immunomodulatory and antioxidative mediators integratively involved in multiple biological processes and pathways indicating their functional association.

Conclusion: Breast ASCs possess superior immunomodulatory and antioxidative capabilities over abdominal ASCs. Our findings shed light on the possible therapeutic applications of breast ASCs in immune-related and oxidative stress-associated diseases.

Keywords: Abdominal adipose tissue; Adipose-derived stem cells (ASCs); Antioxidative potential; Breast adipose tissue; Immunomodulatory potential.

Fig. 1

Morphology of abdominal and breast ASCs at different passages. a, c, and e Abdominal ASCs at passages 0, 1, and 2, respectively. b, d, and f Breast ASCs at passages 0, 1, and 2, respectively. Cells of both types of tissues appear with typical MSCs spindle morphology (scale bar = 200 μm)

Fig. 2

Flow cytometric phenotype analysis for mesenchymal stem cell characteristic surface markers. a Flow cytometry charts of CD90, Cd105, CD44, and CD34. b Surface expression percentages of each marker along with their p-values. c A bar chart representing the flow cytometry percentage results. This figure shows high expression of the mesenchymal stem cell markers, CD44, Cd73, CD90, and CD105; low expression of non-mesenchymal surface markers, CD34 exhibited by both abdominal and breast ASCs with no significant differences (p-value > 0.05)

Fig. 3

Gene expression levels. a Gene expression levels of the immunoregulatory cytokines (TNF, IL-10, IL-6, TSG-6, and IDO) and adipokines (leptin and visfatin) in breast compared to abdominal ASCs represented as ΔΔCт values (* = p-value < 0.05). b Gene expression levels of the antioxidative markers (SOD1, SOD2, CAT, GPX1, and SIRT3–5), the pluripotency and antioxidative transcription factor (STAT3), and the proliferation marker (Ki67) in breast compared to abdominal ASCs represented as ΔΔCт values (* = p-value < 0.05 and # = p-value < 0.05 in 5 samples only)

Fig. 4

Flow cytometry of abdominal and breast ASCs for surface expression of immunoregulatory surface markers. a Flow cytometry charts of CD200, CD271, CD274, and CD276. b Surface expression percentages of each marker along with their p-values. c A bar chart representing the flow cytometry percentage results. Comparable surface expression percentages were observed for both abdominal and breast ASCs as there were no significant differences (p-value > 0.05)

Fig. 5

Protein interaction network for the differentially upregulated gene set in breast ASCs compared to abdominal ASCs as obtained by the STRING database. It shows patterns of interaction between IL-10 and STAT3 [experimental (pink line), database annotation (blue line), and automated text-mining (green line)]; NAMPT and SIRT5 [experimental (pink line), automated text-mining (light-green line), and predicted gene neighborhood (dark green line)]; IDO and STAT3 [coexpression (black line) and automated text-mining (light-green line)]; STAT3 and NAMPT [coexpression (black line) and automated text-mining (light-green line)]; IL-10 and NAMPT; IDO and IL-10; STAT3 and Ki67/MKi67; and IL-10 and Ki67/MKi67 [automated text-mining only (light-green line)]

Fig. 6

Functional association gene network as obtained by GeneMANIA server for the significantly upregulated genes in breast ASCs versus abdominal ones. This network includes twenty functionally associated genes that are coexpressed, colocalized, genetically interact, or share the same pathway with our gene set