Stress Granule (SG) Formation Assay Service

In the complex landscapes of virology, neurodegenerative diseases, and cancer research, understanding stress granule (SG) dynamics is paramount. As a CRO technology pioneer in neurobiology, we offer highly sensitive, multi-dimensional SG formation measurement services. Our cutting-edge techniques provide unparalleled insights into cellular stress responses. For further information regarding the products and services provided, project-specific consultation, and pricing, please submit an inquiry here.

SG Formation in Amyotrophic Lateral Sclerosis (ALS)

There is a strong association between ALS and the formation of SGs. SGs are ribosomal particles formed by cells under stress conditions and consist mainly of untranslated mRNA and RNA-binding proteins (RBPs). These granules play a protective role in the cellular stress response, but their abnormal accumulation and dysfunction may be associated with the development of neurodegenerative diseases such as ALS.

SGs are dynamic cytoplasmic structures that are mainly formed by a phase separation mechanism. TDP-43 is one of the most common pathological features in ALS, and its abnormal accumulation in the cytoplasm is closely related to the formation of SGs. Pathological aggregation of TDP-43 may promote the formation of SGs by inducing endoplasmic reticulum (ER) stress. In addition, TDP-43 mutations also affect the dynamic properties of SGs, making them insoluble and irreversibly aggregated.

Using a 100X objective on a spinning disk confocal microscope, U-2 OS cells expressing GFP-G3BP1 were imaged every 20 seconds for 20 minutes after exposure to 0.5 mM NaAsO₂, in order to track stress granule assembly.¹

SG Formation Assays

• Stress Treatment Induces SG Formation

Selection of Stress Sources: Common stress inducers include sodium arsenite (0.5-1.0 mM, 30-60 minutes), heat shock (42°C, 20 minutes), oxidative stress (H₂O₂, 5 mM, 30 minutes), or hyperosmotic stress (1 M KCl, 10 minutes). Different stressors may trigger distinct subtypes of SGs. For example, the composition of SGs induced by heat shock may differ from those induced by oxidative stress.

Verification of Translation Inhibition: Confirming the inhibition of translation initiation is a crucial prerequisite for SG formation. This can be achieved by detecting eIF2α phosphorylation via Western blot (WB) or by using translation inhibitors such as puromycin or cycloheximide.

• Multi-Marker Detection System for SG Analysis

Leveraging fluorescence labeling techniques targeting core SG proteins (e.g., G3BP1, TIA-1, TIAR) and disease-associated proteins (e.g., TDP-43, FUS), this system enables precise analysis of compositional heterogeneity within SGs under various stress conditions, including oxidative stress, heat shock, and viral infection.

• Image Quantification Analysis

To compare the effects of different stress sources, we quantify the number of SGs per cell. Utilize software such as ImageJ or CellProfiler to analyze SG count, size, and distribution. Live-cell imaging techniques, such as confocal microscopy, allow for real-time recording of SG assembly and disassembly processes. This data can be combined with time-series analysis to study SG dynamics.

Fig.1 Time course of stress granule assembly.¹

Our stress granule formation assay service offers researchers reliable data support due to its high throughput, high sensitivity, and versatility. Whether in basic research or drug development, our service can help you gain a deeper understanding of the biological functions of stress granules and their role in diseases. Please contact us for more details and to discuss cooperation opportunities.

Reference

1. Wheeler, Joshua R., et al. "Distinct stages in stress granule assembly and disassembly." elife 5 (2016): e18413. Distributed under Open Access license CC BY 4.0, without modification.