Increasing proliferation of murine adipose tissue-derived mesenchymal stem cells by TNF-α plus IFN-γ

The objective of the current study was to assess the effects of tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) along with their simultaneous application on proliferation and pluripotency genes of murine adipose tissue-derived mesenchymal stem cells (AT-MSCs). The proliferation, doubling time (DT), colony-forming unit-fibroblast (CFU-F), pluripotency genes expression, and proliferation-related immunomodulatory markers of MSCs were analyzed upon activation with TNF-α (10 ng/ml), IFN-γ (10 ng/ml) and both TNF-α and IFN-γ (5 ng/ml + 5 ng/ml). Pluripotency genes including Oct-4, Sox-2, and Nanog as well as proliferation-associated immunomodulatory cytokines such as insulin-like growth factor 1 (IGF-1) and transforming growth factor-β (TGF-β) expression were evaluated using real-time PCR. Surface expression of Qa2 (HLA-G) was analyzed by flow cytometry. Pretreatment of MSCs with TNF-α plus IFN-γ led to significantly increased proliferation, DT and CFU-F as well as expression of pluripotency genes in AT-MSCs (p < 0.01). MSCs expressed more IGF-1, TGF-β, and Qa2 upon activation with TNF-α plus IFN-γ and IFN-γ. MSCs expressed significantly decreased amounts of TGF-β and Qa2 in presence of TNF-α. TNF-α combined with IFN-γ may be improved the proliferation of AT-MSCs. Conversely, expanded MSCs pointed out low levels of the immunomodulatory marker, s especially Qa2 in the presence of TNF-α. In conclusion, we showed that TNF-α together with IFN-γ increased the proliferation of MSCs and slightly enhanced the expression of pluripotency genes.