Proteomic Characterization of Changes in Mouse Brain Cortex Protein Expression at Different Post-Mortem Intervals: A...

Area of Science:

• Forensic Science
• Biomarker Discovery
• Proteomics

Background:

• Accurate post-mortem interval (PMI) estimation is crucial for thanato-chronological purposes.
• Tissue degradation and precise PMI determination depend heavily on biological sample condition.
• Optimizing tissue handling and identifying sensitive post-mortem biomarkers can establish timelines for post-mortem events.

Purpose of the Study:

• To investigate proteome changes in mouse brain cortex samples over a post-mortem time course.
• To identify potential protein biomarkers indicative of different post-mortem intervals (PMIs).

Main Methods:

• Proteomic analysis of mouse cortex samples collected at various post-mortem time points (0, 4, 8, 12, 24, 32 hours) after cold storage (4 °C).
• Analysis focused on early (<24 h) and late (>24 h) PMIs compared to time-zero (T0) samples.
• Validation using LIFT mass spectrometry and western blot analysis.

Main Results:

• Significant protein level changes were observed compared to T0 samples.
• Calpain11 showed a notable increase in the early PMI (<24 h).
• Caspases 7 and 8, along with Gasdermin 3, increased significantly in the late PMI (>24 h).

Conclusions:

• The identified proteins (Calpain11, Caspases 7/8, Gasdermin 3) show potential as biomarkers for different PMIs.
• These findings suggest a proteomic approach can aid in refining PMI estimation.
• Further investigation in diverse biological samples is warranted to confirm biomarker utility.