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Analysis of Cell Cycle Position in Mammalian Cells
12:19

Analysis of Cell Cycle Position in Mammalian Cells

Published on: January 21, 2012

Transforming growth factor beta 1 promotes cell cycle exit through the cyclin-dependent kinase inhibitor p21 in the

Julie A Siegenthaler1, Michael W Miller

  • 1Department of Neuroscience and Physiology, State University of New York, Upstate Medical University, Syracuse, NY 13210, USA.

The Journal of Neuroscience : the Official Journal of the Society for Neuroscience
|September 24, 2005
PubMed

Insights

Transforming growth factor beta1 (TGFbeta1) promotes cell cycle exit during brain development. This process is linked to increased expression of the p21 protein in neural progenitor cells.

Area of Science:

  • Neuroscience
  • Developmental Biology
  • Cell Biology

Background:

  • Cortical neurogenesis requires precise regulation of cell proliferation and cell cycle exit.
  • Transforming growth factor beta1 (TGFbeta1) is present in developing cerebral cortex regions and is implicated in cell cycle control.

Purpose of the Study:

  • To investigate if TGFbeta1 promotes cell cycle exit in the cortical ventricular zone (VZ).
  • To determine if TGFbeta1 modulates cell cycle proteins, specifically cyclin D1, p27, and p21.

Main Methods:

  • Treatment of cortical VZ cells with TGFbeta1.
  • Analysis of cell cycle length, fraction of cycling cells, and cell cycle exit.
  • Assessment of cell cycle protein expression (cyclin D1, p27, p21) via quantitative analysis.

Main Results:

  • TGFbeta1 treatment reduced the fraction of VZ-cycling cells by 21% and increased cell cycle exit by 24%.
  • TGFbeta1 selectively upregulated p21 expression in the VZ.
  • High p21 expression correlated with VZ cells exiting the cell cycle, and TGFbeta1 increased the number of p21-positive cells exiting the cell cycle.

Conclusions:

  • TGFbeta1 actively promotes cell cycle exit during cortical development.
  • Upregulation of p21 is a key event associated with TGFbeta1-induced cell cycle exit.
  • The mechanism of TGFbeta1-induced cell cycle exit involves the p21 protein.

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