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The role of laminin-5 in TGF alpha/EGF-mediated corneal epithelial cell motility

P Qin1, M A Kurpakus

  • 1Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI 48201, USA.

Experimental Eye Research
|June 17, 1998
PubMed

Insights

Transforming growth factor alpha (TGF alpha) and epidermal growth factor (EGF) stimulate corneal epithelial cell migration. Endogenously secreted laminin-5 aids this motility, while exogenously added laminin-5 promotes cell adhesion.

Area of Science:

  • Ophthalmology
  • Cell Biology
  • Extracellular Matrix Research

Background:

  • Transforming growth factor alpha (TGF alpha) and epidermal growth factor (EGF) are known to promote corneal epithelial cell wound closure.
  • The specific mechanisms by which these growth factors regulate corneal epithelial cell motility, particularly concerning interactions with basement membrane proteins like laminin, remain unclear.

Purpose of the Study:

  • To investigate the role of TGF alpha and EGF in regulating corneal epithelial cell motility on basement membrane proteins.
  • To elucidate the function of laminin-5 in corneal epithelial cell migration and adhesion in response to TGF alpha and EGF stimulation.

Main Methods:

  • Utilized an in vitro model of corneal wound healing.
  • Cultured primary corneal epithelial cells and stimulated them with TGF alpha or EGF.
  • Analyzed the deposition and localization of laminin-5 in the extracellular matrix.
  • Assessed cell motility and adhesion in response to both endogenously secreted and exogenously added laminin preparations.

Main Results:

  • TGF alpha did not negatively impact laminin-5 deposition in the extracellular matrix during simulated wound healing.
  • Corneal epithelial cells stimulated by TGF alpha or EGF exhibited increased motility and secreted a trail of laminin-5.
  • Exogenously added laminin-5 promoted cell adhesion and hemidesmosome formation but did not stimulate motility.
  • A commercial laminin preparation lacking laminin-5 significantly enhanced the migration of TGF alpha- or EGF-stimulated corneal epithelial cells.

Conclusions:

  • Endogenously secreted laminin-5 is hypothesized to play a crucial role in promoting corneal epithelial cell migration stimulated by TGF alpha or EGF.
  • Exogenously applied laminin-5 primarily functions to enhance corneal epithelial cell adhesion rather than motility.
  • These findings differentiate the roles of endogenous versus exogenous laminin-5 in corneal epithelial cell behavior during wound healing.

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