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Polarity, protrusion-retraction dynamics and their interplay during keratinocyte cell migration
1Department of Theoretical Biology, Botanical Institute, University of Bonn, Kirschallee 1, Bonn, D-53115, Germany. t.bretschneider@uni-bonn.de
Experimental Cell Research
|October 20, 2001
Summary
Fibronectin coating concentration significantly impacts keratinocyte migration and cell polarization. Higher fibronectin levels enhance migration and ruffling speeds, but cell polarity remains unaffected by RGD peptide inhibition.
Area of Science:
- Cell Biology
- Biophysics
- Dermatology
Background:
- Keratinocyte migration is crucial for skin repair and involves distinct phases like polarization, extension, attachment, contraction, and detachment.
- Cell polarization establishes asymmetry, leading to the formation of a leading lamella that drives directed cell movement.
- Substrate adhesiveness plays a critical role in regulating cell behavior during migration.
Purpose of the Study:
- To investigate how fibronectin coating concentration and RGD peptide inhibition affect keratinocyte polarization, migration dynamics, lamella formation, and ruffling.
- To understand the relationship between substrate adhesiveness and the speed and characteristics of keratinocyte movement.
- To determine the impact of RGD peptides on cell polarity in the context of varying fibronectin concentrations.
Main Methods:
- Utilizing varying concentrations of fibronectin to coat substrates for observing human epidermal keratinocyte migration.
- Employing competitive inhibition with RGD peptides (GRGDS) to probe the role of specific adhesive interactions.
- Quantifying cell polarization using a polarity index and measuring migration, protrusion, and ruffling speeds.
Main Results:
- A fibronectin concentration of 10 microg/cm(2) significantly increased migration and ruffling speeds (twofold) and protrusion speed (20%) in polar cells compared to 2.5 microg/cm(2).
- Nonpolar cells exhibited constant migration and ruffling speeds irrespective of fibronectin concentration, while protrusion speeds were similar to polar cells.
- RGD peptide treatment on high fibronectin concentrations reduced migration, protrusion, and ruffling speeds, mimicking lower effective coating concentrations, but did not alter the polarity index.
Conclusions:
- Substrate adhesiveness, modulated by fibronectin concentration, is a key regulator of keratinocyte migration speed and lamella dynamics.
- While RGD peptides interfere with adhesion-mediated motility, they do not disrupt the established cell polarity, suggesting complex regulatory mechanisms.
- The findings highlight the differential impact of substrate properties on cell polarization versus migratory speed in epidermal keratinocytes.