In-Situ Spatial Visual Proteomics Enabled by Single-Cell-Type Proximity Biotinylation and Signaling Amplification

Area of Science:

• Proteomics
• Molecular Biology
• Biochemistry

Background:

• Mapping spatial proteome signatures in complex tissues is crucial for understanding physiological and pathological processes.
• Simultaneously visualizing and discovering these spatial proteomic features presents a significant technical challenge.

Purpose of the Study:

• To introduce a novel method, spatial visual proteomics (SVPro), for high-resolution spatial proteomic analysis.
• To enable simultaneous visualization and discovery of proteomic features within intact tissue microenvironments.

Main Methods:

• SVPro integrates single-cell proximity biotinylation with fluorescence signal amplification using a trifunctional probe.
• The trifunctional probe combines radical targeting, clickable fluorescence imaging, and biotinylation for proteome capture within a single tissue section.
• PEGylation and multivalent fluorescent conjugation enhance probe labeling, visualization efficiency, and specificity.

Main Results:

• SVPro successfully performed cell-type proteomic profiling of neuronal subpopulations in mouse brain regions.
• The method identified and validated distinct marker proteins associated with amyloid-β plaques in an Alzheimer's disease mouse model.
• SVPro demonstrated robust and high-resolution visualization of spatial architecture and proteome landscapes.

Conclusions:

• SVPro is a powerful new approach for spatial proteomics, offering simultaneous visualization and proteome landscape analysis.
• This technique provides unique insights into tissue microenvironments by mapping spatial proteomic signatures.
• SVPro has potential applications in understanding disease mechanisms and discovering biomarkers, particularly in neurodegenerative diseases.