TNFR1 signaling resistance associated with female stem cell cytokine production is independent of TNFR2-mediated pathways

Am J Physiol Regul Integr Comp Physiol. 2008 Oct;295(4):R1124-30. doi: 10.1152/ajpregu.90508.2008. Epub 2008 Aug 6.

Abstract

End-organ ischemia is a common source of patient morbidity and mortality. Stem cell therapy represents a novel treatment modality for ischemic diseases and may aid injured tissues through the release of beneficial paracrine mediators. Female bone marrow mesenchymal stem cells (MSCs) have demonstrated a relative resistance to detrimental TNF receptor 1 (TNFR1) signaling and are thought to be superior to male stem cells in limiting inflammation. However, it is not known whether sex differences exist in TNF receptor 2 (TNFR2)-ablated MSCs. Therefore, we hypothesized that 1) sex differences would be observed in wild-type (WT) and TNFR2-ablated MSC cytokine signaling, and 2) the production of IL-6, VEGF, and IGF-1 in males, but not females, would be mediated through TNFR2. MSCs were harvested from male and female WT and TNFR2 knockout (TNFR2KO) mice and were subsequently exposed to TNF (50 ng/ml) or LPS (100 ng/ml). After 24 h, supernatants were collected and measured for cytokines. TNF and LPS stimulated WT stem cells to produce cytokines, but sex differences were only seen in IL-6 and IGF-1 after TNF stimulation. Ablation of TNFR2 increased VEGF and IGF-1 production in males compared with wild-type, but no difference was observed in females. Female MSCs from TNFR2KOs produced significantly lower levels of VEGF and IGF-1 compared with male TNFR2KOs. The absence of TNFR2 signaling appears to play a greater role in male MSC cytokine production. As a result, male, but not female stem cell cytokine production may be mediated through TNFR2 signaling cascades.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cytokines / metabolism*
  • Female
  • Insulin-Like Growth Factor I / metabolism
  • Interleukin-6 / metabolism
  • Lipopolysaccharides / pharmacology
  • Male
  • Mesenchymal Stem Cells / drug effects
  • Mesenchymal Stem Cells / metabolism*
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Models, Biological
  • Receptors, Tumor Necrosis Factor, Type I / physiology*
  • Receptors, Tumor Necrosis Factor, Type II / genetics
  • Receptors, Tumor Necrosis Factor, Type II / physiology*
  • Sex Factors
  • Signal Transduction / physiology*
  • Tumor Necrosis Factor-alpha / pharmacology
  • Vascular Endothelial Growth Factor A / metabolism

Substances

  • Cytokines
  • Interleukin-6
  • Lipopolysaccharides
  • Receptors, Tumor Necrosis Factor, Type I
  • Receptors, Tumor Necrosis Factor, Type II
  • Tnfrsf1a protein, mouse
  • Tumor Necrosis Factor-alpha
  • VEGFA protein, human
  • Vascular Endothelial Growth Factor A
  • Insulin-Like Growth Factor I