MicroRNA Stability in Postmortem FFPE Tissues: Quantitative Analysis Using Autoptic Samples from Acute Myocardial...

Area of Science:

• Biochemistry
• Molecular Biology
• Pathology

Background:

• MicroRNAs (miRNAs) are short nucleic acids with roles in biological processes and cellular stress.
• Their stability and utility as diagnostic biomarkers are under investigation.
• Postmortem miRNA analysis for acute myocardial infarction (AMI) requires validation of RNA integrity and suitable controls.

Purpose of the Study:

• To evaluate miRNA quantification in postmortem cardiac tissue for acute myocardial infarction (AMI) diagnosis.
• To identify stable endogenous controls for miRNA analysis in frozen and formalin-fixed samples.
• To assess the expression of specific miRNA biomarkers in AMI patients.

Main Methods:

• Cardiac tissue samples were collected postmortem (frozen and formalin-fixed).
• RNA integrity was assessed, and quantitative PCR was used for miRNA analysis.
• miR-191 and miR-26b were identified as stable endogenous controls.

Main Results:

• Longer RNAs fragmented in long-term fixed samples, but specific miRNAs remained stable.
• miR-191 and miR-26b demonstrated stable detection postmortem and after fixation.
• miR-499a showed a significant 2.1-fold decrease in AMI patients compared to controls.

Conclusions:

• MicroRNAs are stable in postmortem cardiac tissue, even after long-term formalin fixation.
• Stable miRNAs like miR-191 and miR-26b can serve as reliable endogenous controls.
• miR-499a is a promising biomarker for diagnosing acute myocardial infarction (AMI) in postmortem examinations.