# Influence of Hydraulic Resistance on the Osmotic Engine Model of Cell Migration

> **NIH NIH R01** · JOHNS HOPKINS UNIVERSITY · 2022 · $372,055

## Abstract

Summary
Understanding the mechanisms of cell migration is a fundamental question in cell, developmental and cancer
biology. Decades of research has shown that the molecular underpinnings of cell migration are complex and
the physical mechanisms driving migration are diverse. We have shown that depending on the local
microenvironment, cell migration can be driven by actin polymerization as well as an osmotic gradient-driven
water flux external to the cell. This so-called osmotic engine model (OEM) is prominent when cells are in tightly
confined spaces. In vivo, cells migrate within diverse microenvironments, ranging from dense 3D extracellular
matrices to narrow microchannels present in tissue, to complex somatic spaces with various kinds of physical
obstacles. An open and un-addressed question is what are the important variables that dictate the relative
contribution of actin polymerization-driven and water-based migratory mechanisms in diverse
microenvironments. Recent data reveal that the degree of cell confinement and the hydraulic resistance
experienced by cells represent key factors in determining the mechanisms driving cell movement. Theoretical
modeling utilizing a two-phase model of the cell cytoplasm also predicts that the hydraulic resistance
experienced by the cell dictates the relative contribution of water flow/OEM to the observed cell speed.
Mounting experimental evidence also suggests that cells can sense hydraulic pressure and modulate cell
migration mechanisms. In this grant application, we propose to develop an integrated modeling and
experimental approach to delineate the relative contributions of the actin-phase and the water-phase to cell
migration as a function of external hydraulic resistance. In Aim 1, we propose to directly quantify how hydraulic
resistance influences cell migration speeds by examining cells both in 2D in media with added methylcellulose,
which increases medium viscosity, and inside confining microchannels of varying channel length, which also
modulate hydraulic resistance. The roles of key ion channels and transporters that are involved in setting up
water flux and the energetics of migration will be explored experimentally and theoretically. We will also identify
the key mechanosensitive ion channels responsible for sensing hydraulic resistance. In Aim 2, we will explore
the interplay between actin polymerization, membrane tension changes and OEM in environments of elevated
hydraulic resistance. We will also extend the two-phase theoretical model of cell migration in include
membrane tension and flows. Since cell migration speeds may depend on cell shape, in Aim 3, we will develop
a general two-phase moving boundary method to compute cell movement for arbitrary cell shapes. We will also
explore how OEM influences cell migration in dense vs more porous 3D collagen matrices, which exhibit
different hydraulic resistances. Taken together, we will discover the mechanisms behind the counterintuitive
observati...

## Key facts

- **NIH application ID:** 10457983
- **Project number:** 5R01GM134542-04
- **Recipient organization:** JOHNS HOPKINS UNIVERSITY
- **Principal Investigator:** Konstantinos Konstantopoulos
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $372,055
- **Award type:** 5
- **Project period:** 2019-09-16 → 2024-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10457983

## Citation

> US National Institutes of Health, RePORTER application 10457983, Influence of Hydraulic Resistance on the Osmotic Engine Model of Cell Migration (5R01GM134542-04). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10457983. Licensed CC0.

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