Mass Spectrometry Multiplexed Detection of SARS-CoV-2.

Testing of large populations for virus infection is now a reality worldwide due to the coronavirus (SARS-CoV-2) pandemic. The demand for SARS-CoV-2 testing using alternatives other than PCR led to the development of mass spectrometry (MS)-based assays. However, MS for SARS-CoV-2 large-scale testing have some downsides, including complex sample preparation and slow data analysis. Here, we describe a high-throughput targeted proteomics method to detect SARS-CoV-2 directly from nasopharyngeal and oropharyngeal swabs. This strategy employs fully automated sample preparation mediated by magnetic particles, followed by detection of SARS-CoV-2 nucleoprotein peptides by turbulent flow chromatography coupled with tandem mass spectrometry.

Proteome analysis of acute kidney injury - Discovery of new predominantly renal candidates for biomarker of kidney disease.

The main bottleneck in studies aiming to identify novel biomarkers in acute kidney injury (AKI) has been the identification of markers that are organ and process specific. Here, we have used different tissues from a controlled porcine renal ischemia/reperfusion (I/R) model to identify new, predominantly renal biomarker candidates for kidney disease. Urine and serum samples were analyzed in pre-ischemia, ischemia (60min) and 4, 11 and 16h post-reperfusion, and renal cortex samples after 24h of reperfusion. Peptides were analyzed on the Q-Exactive™. In renal cortex proteome, we observed an increase in the synthesis of proteins in the ischemic kidney compared to the contralateral, highlighted by transcription factors and epithelial adherens junction proteins. Intersecting the set of proteins up- or down-regulated in the ischemic tissue with both serum and urine proteomes, we identified 6 proteins in the serum that may provide a set of targets for kidney injury. Additionally, we identified 49, being 4 predominantly renal, proteins in urine. As prove of concept, we validated one of the identified biomarkers, dipeptidyl peptidase IV, in a set of patients with diabetic nephropathy. In conclusion, we identified 55 systemic proteins, some of them predominantly renal, candidates for biomarkers of renal disease. BIOLOGICAL SIGNIFICANCE: The main bottleneck in studies aiming to identify novel biomarkers in acute kidney injury (AKI) has been the identification of markers that are predominantly renal. In fact, putative biomarkers for this condition have also been identified in a number of other clinical scenarios, such as cardiovascular diseases, chronic kidney failure or in patients being treated in intensive care units from a number of conditions. Here we propose a comprehensive, sequential screening procedure able to identify and validate potential biomarkers for kidney disease, using kidney ischemia/reperfusion as a paradigm for a kidney pathological event.