Volume 6 • Issue 3 • 1000331 J Stem Cell Res Ther ISSN: 2157-7633 JSCRT, an open access journal Open Access Research Article Journal of Stem Cell Research & Therapy J o u r n a l o f S t e m C e ll R e s e a r c h & T h e r a p y ISSN: 2157-7633 Baer et al., J Stem Cell Res Ther 2016, 6:3 DOI: 10.4172/2157-7633.1000331 Abstract Objective: Stem cell-based therapy seems to be a promising option to support regeneration after organ failure and tissue injury. The transplantation of MSCs requires cells with a maximum regenerative capacity. Therefore, the research on new strategies to improve the release of regenerative factors of MSCs is urgently needed. Methods: Human adipose-derived stromal/stem cells (ASC) were isolated from lipoaspirates, characterized, and cultured. Cells were either cultured under standard conditions or preconditioned by incubation in a hypoxic environment (0.5% O 2 ) or in normoxia in the presence of recombinant human tumor necrosis factor-α (TNFα) or recombinant human epidermal growth factor (EGF) for 48 hours. First, seven selected regeneration promoting factors were evaluated by qPCR analysis. Afterwards the secretome of ASCs was estimated using a commercially available protein array for 507 proteins. Results: PCR analysis showed a differential induction of ASCs` gene expression by the three pretreatments. Whereas ASCs in hypoxia showed a signifcant mRNA induction of VEGF, FGF-7, and IGF-II, the other pretreatments induced no signifcant change in VEGF expression. The gene expression of HB-EGF and M-CSF was signifcantly induced in hypoxia and by incubation with TNFα, but not EGF. Angiopoietin-like 1 mRNA was not signifcantly induced by all three preconditioning regimens. Evaluation by the protein array revealed that from the 507 proteins investigated 21.9% were found to be more than fve-fold increased after incubation in hypoxia (111 of 507 proteins). Preincubation with EGF resulted in an upregulation of 32.3% (164/507), whereas TNFα upregulated 28.8% of all proteins evaluated (146/507). Conclusion: The fndings indicate that all three preconditioning regimens induced a wide variety of proteins. However, short-term pretreatment with EGF induced the highest quantity of proteins, and, therefore, appears to be the best preconditioning regime for cell therapeutic approaches. Preconditioning of Human Adipose-derived Stromal/Stem Cells: Evaluation of Short-term Preincubation Regimens to Enhance their Regenerative Potential Patrick C Baer 1 *, Jürgen M Overath 1 , Anja Urbschat 2 , Ralf Schubert 3 and Helmut Geiger 1 1 Division of Nephrology, Department of Internal Medicine III, Goethe-University, 60590 Frankfurt/M., Germany 2 Department of Urology and Pediatric Urology, University Hospital Marburg, Philipps-University, 35043 Marburg, Germany 3 Department of Paediatrics, Goethe-University, 60590 Frankfurt/M., Germany *Corresponding author: Patrick C Baer, M.D, Ph.D, Johann Wolfgang Goethe University, Department of Internal Medicine III, Division of Nephrology, Theodor- Stern-Kai 7, 60590 Frankfurt/M., Germany, Tel: 0049/69/6301-5554; Fax: 0049/69/6301-4749; E-mail: patrick.baer@kgu.de Received February 29, 2016; Accepted March 12, 2016; Published March 19, 2016 Citation: Baer PC, Overath JM, Urbschat A, Schubert R, Geiger H (2016) Preconditioning of Human Adipose-derived Stromal/Stem Cells: Evaluation of Short-term Preincubation Regimens to Enhance their Regenerative Potential. J Stem Cell Res Ther 6: 331. doi:10.4172/2157-7633.1000331 Copyright: © 2016 Baer PC, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Keywords: Preconditioning; Pretreatment; Stem cells; Medium; Regeneration; Hypoxia; Mesenchymal stromal/stem cells Abbreviations: ASCs: Adipose-derived Mesenchymal Stromal/ Stem Cells; EGF: Epidermal Growth Factor; FGF-7: Fibroblast Growth Factor-7; HB-EGF: Heparin-Binding EGF-like Growth Factor; Hyp: Preconditioning in a Hypoxic Environment; IGF-II: Insulin-like Growth Factor-II; M-CSF: Macrophage Colony-Stimulating Factor; MIP-1: Macrophage Infammatory Protein 1; MSCs: Mesenchymal Stromal/Stem Cells; qPCR: quantitative Real Time Polymerase Chain Reaction; TNFα: Tumor Necrosis Factor-alpha; VEGF: Vascular Endothelial Growth Factor Introduction Stem cell-based therapy seems to be a promising option to support regeneration afer organ failure and tissue injury. Te organ- protective efects of mesenchymal stromal/stem cells (MSCs) and their conditioned medium (CM) have been investigated in the last decade, demonstrating that either transplanted cells or their CM promote regeneration afer several organ- and tissue injuries. Te transplantation of MSCs requires cells with a maximum regenerative capacity. Terefore, the development of new strategies to improve the release of regenerative factors of MSCs is urgently needed. In vitro pretreatment regimens able to optimize the regenerative capacity of stem cells should be in the focus of further studies aiming to enhance the regeneration process. During the last years, optimization of the benefcial efects of cell therapy has been investigated, seeking to enhance survival, engrafment, and paracrine properties of MSCs [1]. In this case, various in vitro pretreatment strategies (“preconditioning”) have been recently applied to enhance the regenerative capacity of MSCs [2-4]. MSC pretreatment may include exposure of cells to physiological stimuli such as cytokines, growth factors, biophysical stimuli, heat shock, pharmacological agents, cell-cell-contacts, or hypoxia [1-4]. Preconditioning by hypoxia has been shown to initiate the secretion of regenerative factors and to enhance cell survival [5,6]. Findings of others suggest that hypoxic preincubation of MSCs for two days induces metabolic changes that yield higher in vivo cell retention afer transplantation [6]. Terefore, choosing appropriate pretreatment regimens may provide a simple but efective way of promoting survival