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Spatial and Temporal Analysis of Active ERK in the C. elegans Germline
08:40

Spatial and Temporal Analysis of Active ERK in the C. elegans Germline

Published on: November 29, 2016

Age-related decline in Ras/ERK mitogen-activated protein kinase cascade is linked to a reduced association between

D Hutter1, Y Yo, W Chen

  • 1Laboratory of Biological Chemistry, National Institute on Aging, Gerontology Research Center, Baltimore, Maryland 21224, USA.

The Journals of Gerontology. Series A, Biological Sciences and Medical Sciences
|May 5, 2000
PubMed

Insights

Cell proliferation decreases with age due to impaired ERK signaling. Aged hepatocytes show reduced Shc-EGFR complex formation, impacting the extracellular signal-regulated kinase (ERK) pathway and cell division.

Area of Science:

  • Cellular senescence
  • Molecular biology
  • Aging research

Background:

  • Cellular proliferation capacity diminishes with advanced age.
  • Age-related decline in proliferation is linked to reduced extracellular signal-regulated kinase (ERK) and p70 S6 kinase (p70(S6k)) activity.

Purpose of the Study:

  • To investigate the molecular mechanisms behind age-related defects in the ERK signaling pathway.
  • To characterize upstream signaling events following epidermal growth factor (EGF) stimulation in young versus aged hepatocytes.

Main Methods:

  • Utilized rat primary hepatocytes as a model system.
  • Stimulated hepatocytes with EGF and analyzed the activity of key signaling proteins including MEK, Ras, and the epidermal growth factor receptor (EGFR).
  • Assessed tyrosine phosphorylation and complex formation of EGFR and Shc adaptor protein.

Main Results:

  • Aged hepatocytes exhibited significantly lower MEK and Ras activities post-EGF stimulation compared to young hepatocytes.
  • EGFR levels and tyrosine phosphorylation of EGFR and Shc were comparable between young and aged cells.
  • Crucially, Shc failed to form stable complexes with EGFR in aged hepatocytes after EGF stimulation.

Conclusions:

  • The age-related decrease in the association between Shc and EGFR is identified as a key factor underlying impaired ERK signaling.
  • This molecular defect in the ERK pathway contributes to the reduced proliferative capacity observed in aged cells.

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