Rapid Single-Cell Measurement of Transient Transmembrane Water Flow under Osmotic Gradient

TL;DR

This paper presents a novel rapid measurement technique for detecting transmembrane water flow in single cells, enabling detailed study of aquaporin function and regulation with high spatiotemporal resolution.

Contribution

The authors develop a new method to directly measure water transport through aquaporins in single adherent cells, overcoming previous limitations of sensitivity and resolution.

Findings

Enables direct measurement of AQP-mediated water flow

Provides insights into AQP regulation and cytoplasmic flow dynamics

Offers a new tool for single-cell water transport studies

Abstract

While aquaporin (AQP) gating dynamically regulates transmembrane water permeability for cellular homeostasis, its mechanisms remain poorly understood compared to ion channels. A central challenge is the lack of methods to measure water flow through AQPs with the spatiotemporal resolution and sensitivity equivalent to patch-clamp recordings of ion fluxes, a limitation stemming from the electrically silent nature of water transport. We introduce a technique to rapidly detect cytoplasmic flows induced by osmotic-gradient-driven transmembrane water transport in single adherent human cancer cells. This approach enables direct measurement of AQP-mediated water transport and provides a powerful tool to investigate AQP function and regulation and cytoplasmic flow dynamics at the single-cell level.