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TGF-β1 prevents up-regulation of the P2X7 receptor by IFN-γ and LPS inleukemic THP-1 monocytes

Journal Article


Abstract


  • The P2X7 receptor is an extracellular ATP-gated cation channel critical in inflammation and immunity, and can be up-regulated by IFN-γ and LPS. This study aimed to examine the effect of TGF-β1 on the up-regulation of P2X7 function and expression in leukemic THP-1 monocytes differentiated with IFN-γ and LPS. Cell-surface molecules including P2X7 were examined by immunofluorescence staining. Total P2X7 protein and mRNA was assessed by immunoblotting and RT-PCR respectively. P2X7 function was evaluated by ATP-induced cation dye uptake measurements. Cell-surface P2X7 was present on THP-1 cells differentiated for 3days with IFN-γ and LPS but not on undifferentiated THP-1 cells. ATP induced ethidium(+) uptake into differentiated but not undifferentiated THP-1 cells, and the P2X7 antagonist, KN-62, impaired ATP-induced ethidium(+) uptake. Co-incubation of cells with TGF-β1 plus IFN-γ and LPS prevented the up-regulation of P2X7 expression and ATP-induced ethidium(+) uptake in a concentration-dependent fashion with a maximum effect at 5ng/ml and with an IC(50) of ~0.4ng/ml. Moreover, ATP-induced YO-PRO-1(2+) uptake and IL-1β release were abrogated in cells co-incubated with TGF-β1. TGF-β1 also abrogated the amount of total P2X7 protein and mRNA induced by IFN-γ and LPS. Finally, TGF-β1 prevented the up-regulation of cell-surface CD86, but not CD14 and MHC class II, by IFN-γ and LPS. These results indicate that TGF-β1 prevents the up-regulation of P2X7 function and expression by IFN-γ and LPS in THP-1 monocytes. This suggests that TGF-β1 may limit P2X7-mediated processes in inflammation and immunity.

Authors


  •   Gadeock, Safina (external author)
  •   Tran, Jimmy N. (external author)
  •   Georgiou, Jennifer (external author)
  •   Jalilian, Iman (external author)
  •   Taylor, Rosanne M. (external author)
  •   Wiley, James S. (external author)
  •   Sluyter, Ronald

Publication Date


  • 2010

Citation


  • Gadeock, S., Tran, J. N. S. N., Georgiou, J. G., Jalilian, I., Taylor, R. M., Wiley, J. S. & Sluyter, R. (2010). TGF-β1 prevents up-regulation of the P2X7 receptor by IFN-γ and LPS inleukemic THP-1 monocytes. Biochimica et Biophysica Acta: international journal of biochemistry and biophysics, 1798 (11), 2058-2066.

Scopus Eid


  • 2-s2.0-84755161778

Ro Metadata Url


  • http://ro.uow.edu.au/scipapers/5078

Number Of Pages


  • 8

Start Page


  • 2058

End Page


  • 2066

Volume


  • 1798

Issue


  • 11

Place Of Publication


  • http://www.elsevier.com/locate/bba

Abstract


  • The P2X7 receptor is an extracellular ATP-gated cation channel critical in inflammation and immunity, and can be up-regulated by IFN-γ and LPS. This study aimed to examine the effect of TGF-β1 on the up-regulation of P2X7 function and expression in leukemic THP-1 monocytes differentiated with IFN-γ and LPS. Cell-surface molecules including P2X7 were examined by immunofluorescence staining. Total P2X7 protein and mRNA was assessed by immunoblotting and RT-PCR respectively. P2X7 function was evaluated by ATP-induced cation dye uptake measurements. Cell-surface P2X7 was present on THP-1 cells differentiated for 3days with IFN-γ and LPS but not on undifferentiated THP-1 cells. ATP induced ethidium(+) uptake into differentiated but not undifferentiated THP-1 cells, and the P2X7 antagonist, KN-62, impaired ATP-induced ethidium(+) uptake. Co-incubation of cells with TGF-β1 plus IFN-γ and LPS prevented the up-regulation of P2X7 expression and ATP-induced ethidium(+) uptake in a concentration-dependent fashion with a maximum effect at 5ng/ml and with an IC(50) of ~0.4ng/ml. Moreover, ATP-induced YO-PRO-1(2+) uptake and IL-1β release were abrogated in cells co-incubated with TGF-β1. TGF-β1 also abrogated the amount of total P2X7 protein and mRNA induced by IFN-γ and LPS. Finally, TGF-β1 prevented the up-regulation of cell-surface CD86, but not CD14 and MHC class II, by IFN-γ and LPS. These results indicate that TGF-β1 prevents the up-regulation of P2X7 function and expression by IFN-γ and LPS in THP-1 monocytes. This suggests that TGF-β1 may limit P2X7-mediated processes in inflammation and immunity.

Authors


  •   Gadeock, Safina (external author)
  •   Tran, Jimmy N. (external author)
  •   Georgiou, Jennifer (external author)
  •   Jalilian, Iman (external author)
  •   Taylor, Rosanne M. (external author)
  •   Wiley, James S. (external author)
  •   Sluyter, Ronald

Publication Date


  • 2010

Citation


  • Gadeock, S., Tran, J. N. S. N., Georgiou, J. G., Jalilian, I., Taylor, R. M., Wiley, J. S. & Sluyter, R. (2010). TGF-β1 prevents up-regulation of the P2X7 receptor by IFN-γ and LPS inleukemic THP-1 monocytes. Biochimica et Biophysica Acta: international journal of biochemistry and biophysics, 1798 (11), 2058-2066.

Scopus Eid


  • 2-s2.0-84755161778

Ro Metadata Url


  • http://ro.uow.edu.au/scipapers/5078

Number Of Pages


  • 8

Start Page


  • 2058

End Page


  • 2066

Volume


  • 1798

Issue


  • 11

Place Of Publication


  • http://www.elsevier.com/locate/bba