CD105 inhibits transforming growth factor-beta-Smad3 signalling

Baoqiang Guo1, Mark Slevin, Chenggang Li

  • 1Laboratory Medicine Academic Group, Medical School, University of Manchester, Manchester, UK. Mqbssbg5@fs1.scg.man.ac.uk

Anticancer Research
|July 28, 2004
PubMed

Insights

CD105 (endoglin) antagonizes transforming growth factor-beta 1 (TGF-beta1) signaling, inhibiting cell proliferation and Smad3 pathway activation. This suggests CD105 plays a role in regulating angiogenesis via TGF-beta1 modulation.

Area of Science:

  • Molecular Biology
  • Cell Biology
  • Biochemistry

Background:

  • CD105 (endoglin) is a TGF-beta receptor component highly expressed during angiogenesis.
  • Understanding CD105's role in angiogenesis requires investigating its modulation of TGF-beta1 signaling.

Purpose of the Study:

  • To elucidate the molecular mechanism of CD105 in angiogenesis by studying its effect on TGF-beta1 signaling.
  • To investigate how CD105 overexpression impacts TGF-beta1-mediated cellular responses.

Main Methods:

  • Utilized CD105-transfected rat myoblasts as an in vitro model.
  • Assessed TGF-beta1-mediated inhibition of cell proliferation.
  • Measured luciferase activity driven by PAI-1 and CAGA promoter elements.
  • Analyzed Smad3 phosphorylation and nuclear translocation.
  • Investigated JNK1 and c-Jun phosphorylation.

Main Results:

  • CD105 overexpression antagonized TGF-beta1-induced inhibition of cell proliferation.
  • Reduced TGF-beta1-mediated luciferase activity from both p3TP-Lux (PAI-1 promoter) and (CAGA)12-Luc reporters.
  • Decreased Smad3 serine phosphorylation and nuclear translocation.
  • Increased JNK1 phosphorylation, potentially activating c-Jun.

Conclusions:

  • CD105 inhibits TGF-beta1/Smad3 signaling by reducing Smad3 phosphorylation and nuclear translocation.
  • CD105 may also inhibit Smad3 signaling indirectly via JNK1 activation of c-Jun.
  • These findings provide insights into CD105's molecular mechanism in angiogenesis regulation.

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