Array-based in situ fluorescence assay for profiling multiplex matrix metalloproteinases activities in tissue section

Area of Science:

• Biochemistry
• Molecular Biology
• Analytical Chemistry

Background:

• Matrix metalloproteinases (MMPs) are crucial enzymes involved in various physiological and pathological processes.
• Accurate and sensitive detection of MMPs activity is essential for understanding disease mechanisms and developing targeted therapies.
• Existing methods for MMPs activity profiling often require complex separation or extraction steps, limiting their applicability.

Purpose of the Study:

• To develop and validate a novel array-based in situ fluorescence assay for high-throughput and localized analysis of multiplex matrix metalloproteinases (MMPs) activities.
• To assess the sensitivity and practicality of the assay for analyzing MMPs expression patterns in cell monolayers and tissue sections.
• To demonstrate the utility of the assay in drug discovery by evaluating compound inhibition potencies and profiling MMPs in clinical samples.

Main Methods:

• Development of an array-based assay utilizing peptide substrates with FRET pairs (FAM/Dabcyl) for five specific MMPs (MMP-2, -3, -7, -9, -14).
• Direct application of substrates onto cell monolayers or tissue sections for in situ MMPs activity detection via fluorescence recovery.
• Quantification of MMPs activity based on fluorescence intensity of FAM-labeled peptide fragments internalized by cells.
• Validation through assessment of compound inhibition potencies and profiling of MMPs in thyroid tissue samples.

Main Results:

• The assay successfully detected and localized multiplex MMPs activities in cell monolayers and tissue sections with high sensitivity (down to hundreds of cells/cm²).
• Demonstrated suitability for identifying MMPs expression patterns and quantifying secreted MMPs activities.
• Validated the assay's feasibility by accurately evaluating the inhibition potencies of six compounds against five target MMPs.
• Successfully profiled MMPs activities in localized regions of 32 thyroid tissue samples without prior separation or extraction.

Conclusions:

• The proposed array-based in situ fluorescence assay offers a sensitive, high-throughput, and practical method for analyzing multiplex MMPs activities.
• The assay eliminates the need for sample separation or extraction, enabling direct profiling in complex biological matrices.
• This technique holds significant potential for applications in drug discovery, biomarker development, and disease diagnostics.