Microgenomics 2021 webinar EV & Circulating Biomarkers - MPfaffl
Channel: The International Symposium on Microgenomics 2023
Date: 2022-01-03

Michael Pfaffl (Technical University of Munich, Germany) presents "EV associated Biomarkers in Liquid Biopsies -- How to identify valid ‘Biomarker Signatures’ in blood and circulating extracellular vesicle"

Extracellular vesicles (EVs) circulate in body liquids and are involved in the intercellular communication, and they have important regulative functions in almost any physiological or pathological process. In recent time, especially the exosomes or exosome-like small EV have gained huge scientific interest because of their molecular diagnostic potential, mainly based on their nucleic acid and microRNA content.

Herein we compared the overall performance of various optimized isolation principles for serum EVs/exosomes, primarily from blood compartments, in healthy individuals and various cohorts of critically ill patients. Furthermore, we investigated combined EV isolation methods and compared cell-free and vesicular microRNAs from matched arterial and venous sera. Optimized isolation methods were benchmarked regarding their suitability for microRNA biomarker discovery as well as biological characteristics of captured EVs, according to the latest MISEV 2018 quality control guidelines. To analyze the small-RNA deep sequencing results, a self-established bioinformatics R pipeline for microRNA was applied and isomiRROR for the deep analysis of their isoforms. Differential expressed microRNAs candidates were analyzed by multivariate statistics (HCA, PCA, PLS-DA) to find reliable biomarker signatures. Final goal was the development of a valid microRNA biomarker signature for an early diagnosis and a valid classification of critical ill patients. Various patient cohorts were investigated: healthy volunteers, mild- or severe pneumonia, acute pulmonary failure (ARDS), septic shock, and recently Covid-19 patients. Distinct miRNA signatures could be identified, which are applicable to indicate disease progression from limited inflammation present in pneumonia to severe inflammatory changes as seen in ARDS, septic shock or Covid-19.

The study results indicate that EV associated miRNA biomarkers have high potential for early diagnosis of pneumonia and to indicate disease progression towards severe inflammation events towards Covid-19. Furthermore the methodological findings provides guidance for navigating the multitude of EV/exosome isolation methods available, and helps researchers and clinicians in the field of molecular diagnostics to make the right choice about the EV/exosome isolation strategy and data analysis pipeline.