Antifibrotic TSG-6 Expression Is Synergistically Increased in Both Cells during Coculture of Mesenchymal Stem Cells and Macrophages via the JAK/STAT Signaling Pathway

Int J Mol Sci. 2022 Oct 28;23(21):13122. doi: 10.3390/ijms232113122.

Abstract

The pro-inflammatory cytokines tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-1β upregulate TNF-α-stimulated gene 6 (TSG-6); however, current knowledge about the optimal conditions for TSG-6 expression in mesenchymal stem cells (MSCs) is limited. Here, we investigated whether TSG-6 expression varies depending on the polarization state of macrophages co-cultured with adipose tissue-derived stem cells (ASCs) and analyzed the optimal conditions for TSG-6 expression in ASCs. TSG-6 expression increased in ASCs co-cultured with M0, M1, and M2 macrophages indirectly; among them, M1 macrophages resulted in the highest increase in TSG-6 expression in ASCs. TSG-6 expression in ASCs dramatically increased by combination (but not single) treatment of TNF-α, IL-1β, interferon-gamma (IFN-γ), and lipopolysaccharide (LPS). In addition, phosphorylation of signal transducer and activator of transcription (STAT) 1/3 was observed in response to IFN-γ and LPS treatment but not TNF-α and/or IL-1β. STAT1/3 activation synergistically increased TNF-α/IL-1β-dependent TSG-6 expression, and JAK inhibitors suppressed TSG-6 expression both in ASCs and macrophages. In LX-2 hepatic stellate cells, TSG-6 inhibited TGF-β-induced Smad3 phosphorylation, resulting in decreased α-smooth muscle actin (SMA) expression. Moreover, fibrotic activities of LX-2 cells induced by TGF-β were dramatically decreased after indirect co-culture with ASCs and M1 macrophages. These results suggest that a comprehensive inflammatory microenvironment may play an important role in determining the therapeutic properties of ASCs by increasing TSG-6 expression through STAT1/3 activation.

Keywords: TSG-6; anti-fibrosis; hepatic stellate cells; macrophages; mesenchymal stem cells.

MeSH terms

  • Coculture Techniques
  • Interferon-gamma / metabolism
  • Lipopolysaccharides* / metabolism
  • Lipopolysaccharides* / pharmacology
  • Macrophages / metabolism
  • Mesenchymal Stem Cells* / metabolism
  • Signal Transduction
  • Transforming Growth Factor beta / metabolism
  • Tumor Necrosis Factor-alpha / metabolism
  • Tumor Necrosis Factor-alpha / pharmacology

Substances

  • Lipopolysaccharides
  • Tumor Necrosis Factor-alpha
  • Interferon-gamma
  • Transforming Growth Factor beta