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Integrin and phosphotyrosine expression in normal and migrating newt keratinocytes
D J Donaldson1, J T Mahan, H Yang
1Department of Anatomy and Neurobiology, University of Tennessee, Memphis 38163.
The Anatomical Record
|January 1, 1995
Summary
Integrins (beta 1 and beta 4) and phosphotyrosine accumulate at wound sites in migrating keratinocytes, suggesting their role in cell adhesion and behavior modulation during healing. Newt keratinocytes show constitutive activation, differing from human cells, potentially explaining faster wound repair.
Area of Science:
- Cell Biology
- Dermatology
- Integrin Biology
Background:
- Cells utilize integrins, cell surface receptors, to interact with the extracellular matrix.
- Integrin function is influenced by alpha and beta subunit composition and ligand binding.
- Integrin-ligand binding can modulate cell behavior via intracellular protein tyrosine phosphorylation.
Purpose of the Study:
- To investigate the expression and localization of beta 1 and beta 4 integrin subunits and phosphotyrosine in normal and migrating keratinocytes.
- To determine the adhesive properties of keratinocytes to fibronectin and collagen.
- To compare beta 1 integrins in migrating versus non-migrating keratinocytes.
Main Methods:
- Immunohistochemistry to detect integrin subunits and phosphotyrosine.
- Adhesion assays to assess keratinocyte interaction with fibronectin and collagen.
- Polyacrylamide gel electrophoresis and immunoblotting to analyze beta 1 integrins.
Main Results:
- Beta 1 and beta 4 integrins, along with phosphotyrosine, were highly concentrated at the wound bed interface in migrating keratinocytes.
- Normal keratinocytes adhered to and spread on fibronectin and type I collagen.
- No significant changes in the amount or apparent size of beta 1 integrins were observed in migrating keratinocytes compared to normal ones.
Conclusions:
- Beta 1 and beta 4 integrins likely facilitate the attachment of migrating keratinocytes to extracellular matrix proteins at wound sites.
- Phosphotyrosine accumulation suggests integrin-ligand interactions modulate keratinocyte behavior through protein phosphorylation.
- Constitutively activated newt keratinocytes, unlike human keratinocytes, may contribute to faster epidermal wound healing.