Electric Field–Induced Cellular Polarity and Force Signaling in Fibroblasts

Overview

This project investigates how externally applied electric fields influence cellular behavior through coupled biochemical and mechanical pathways. While electrotaxis is well established, the mechanisms linking electrical cues to intracellular signaling and force generation remain not well understood. This study focuses on whether electric field–induced membrane polarity, mediated by PIP3, is sufficient to drive downstream adhesion signaling through FAK, or whether mechanical force generation is required.

Although this work uses controlled DC electric fields at the cellular level, it aims to provide foundational insight into how bioelectric environments may influence cell–matrix interactions and tissue behavior more broadly.

This study addresses a fundamental gap in understanding how electrical cues are converted into mechanical cell behavior. By clarifying the relationship between membrane polarity, intracellular signaling, and force generation, the work provides a mechanistic framework that may inform future studies of how bioelectric environments influence tissue function. While not directly assessing injury risk or long-term exposure effects, these findings could contribute foundational knowledge relevant to evaluating potential biological responses to EMF exposure.

The project will be conducted at the Blizard Institute spanning 2-3 months under the supervision of an Associate Professor of bioelectricity and biomaterials engineering from Queen Mary University London.

Introduction

EMFs are increasingly recognized as modulators of biological systems, with established roles in wound healing and tissue regeneration. However, the mechanisms by which electrical cues are transduced into changes in cellular behavior in relation to force generation remain unclear.

At the cellular level, electric fields can induce polarization of signaling lipids such as PIP3 via PI3K-dependent pathways, establishing directional cues for migration. In parallel, focal adhesion signaling mediated by FAK regulates how cells generate and transmit mechanical forces to the extracellular matrix. While both processes are known to contribute to cell migration, the causal relationship between electrical polarity, biochemical signaling, and mechanical output remains unresolved.

Understanding this relationship is important not only for basic cell biology but also for evaluating how bioelectric environments might influence tissue integrity over time. Rather than directly testing long-term physiological effects, this study focuses on identifying fundamental mechanisms linking electric fields to cellular force generation with fibroblasts.

Central hypothesis: whether electric field–induced polarity (PIP3) is sufficient to drive downstream FAK activation and adhesion signalling?

Materials and Procedures

Model system: cultured fibroblast cell lines placed under an electrotaxis chamber.

Sample size: ~30–50 cells per condition per replicate, with ≥3 biological replicates

Fibroblasts will be cultured on ECM-coated substrates (e.g., fibronectin) under standard conditions.

DC electric fields (1–2 V/cm) will be applied using a custom electrotaxis chamber. The electric field strengths used in this study are selected to reliably induce measurable cellular responses, allowing mechanistic interrogation of signaling pathways under controlled conditions.

Cells will be transfected with a PH-domain GFP biosensor for PIP3 imaging to determine cellular polarity

Time-lapse fluorescence imaging will be used to quantify polarity

Immunostaining for phosphorylated FAK (pY397) to monitor FAK activity

Quantification via fluorescence intensity at focal adhesions

For mechanistic controls, we will utilise FAK inhibitors to probe the downstream signaling following electric field induced PIP3 polarity. With this, we can monitor the migration of the fibroblasts in order to test whether it is a significant contributing factor for translating cellular polarity into mechanical output for electrotaxis.

To pertube the contractility, we will use blebbistatin which inhibits myosin II ATPase activity and therefore prevents actomyosin contraction, effectively removing force generation whilst preserving upstream signaling with PIP3. This would isolate the force driven effects on FAK and allow us to study the direct correlation between cellular polarity and FAK activity.

Planned Analyses

Preprocessing:

Image segmentation of cell boundaries, normalization of fluorescence intensity and spatial polarity index calculation.

Statistical Analysis:

Comparisons across conditions using ANOVA or t-tests and correlation analysis between PIP3 polarity and FAK activation.

References

McCaig, C. D., Rajnicek, A. M., Song, B. & Zhao, M. Controlling cell behavior electrically: current views and future potential. Physiol. Rev. 95, 943–978 (2015).

Sun, Y. & Zhao, M. Electrotaxis of cells in physiological electric fields. Front. Physiol. 6, 143 (2015).

Bioelectric regulation of cellular function and tissue structure. Res. Sq. (preprint) https://doi.org/10.21203/rs.88495/v1 (2020).

Electric Field–Induced Cellular Polarity and Force Signaling in Fibroblasts

Proposal

Proposal

Proposal

Proposal

Electric Field–Induced Cellular Polarity and Force Signaling in Fibroblasts

Funding Progress

Nonprofit Recipient

DOI

Proposal

Proposal

Funding Progress

Nonprofit Recipient

DOI

Funding Progress

Nonprofit Recipient

DOI