A small-molecule probe to decipher stress-induced ER microenvironments and ER-Golgi communication

Area of Science:

• Cellular Biology
• Biochemistry
• Microscopy

Background:

• Cellular stress impacts organismal and microenvironmental homeostasis.
• Micropolarity changes in cellular compartments are vital for early disease diagnosis.
• The endoplasmic reticulum (ER) plays a key role in cellular stress responses.

Purpose of the Study:

• To quantitatively study micropolarity changes within the ER during cell cycle phases.
• To investigate the utility of a novel fluorophore, ER-Oct, for ER stress assessment.
• To explore ER-Oct's potential in visualizing ER-related biological processes.

Main Methods:

• Utilized a novel, biocompatible fluorophore, ER-Oct, for selective ER staining.
• Employed lambda scanning and fluorescence lifetime imaging microscopy (FLIM) for quantitative analysis.
• Applied live-cell fluorescence microscopy to visualize ER to Golgi transport.

Main Results:

• Induced ER stress led to cell cycle arrest and a measurable increase in ER micropolarity.
• ER-Oct demonstrated efficient ER staining in various cell types, tissues, and model organisms.
• The probe successfully visualized ER to Golgi transport in live cells.

Conclusions:

• ER-Oct is a versatile tool for quantifying ER micropolarity and studying ER stress.
• This approach offers a new method for understanding proteostasis in diverse biological systems.
• The findings support the use of ER micropolarity as a biomarker for early disease diagnosis.