Multiple reaction monitoring (MRM)-profiling with biomarker identification by LC-QTOF to characterize coronary artery disease

Abstract

Metabolite profiling by mass spectrometry (MS) is an area of interest for disease diagnostics, biomarker discovery, and therapeutic evaluation. A recently developed approach, multiple reaction monitoring (MRM)-profiling, searches for metabolites with precursor (Prec) and neutral loss (NL) scans in a representative sample and creates a list of ion transitions. These are then used in an MRM method for fast screening of individual samples and discrimination between healthy and diseased. A large variety of functional groups are considered and all signals discovered are recorded in the individual samples, making this a largely unsupervised method. MRM-profiling is described here and then demonstrated with data for over 900 human plasma coronary artery disease (CAD) samples. Representative pooled samples for each condition were interrogated using a library of over a hundred Prec and NL scans on a triple quadrupole MS. The data from the Prec and NL experiments were converted into ion transitions, initially some 1266 transitions. Each ion transition was examined in the individual samples on a time scale of milliseconds per transition, which allows for rapid screening of large sample sets (<5 days for 1000 samples). Use of univariate and multivariate statistics allowed classification of the sample set with high accuracy. The metabolite profiles classified the CAD female, CAD male, and peripheral artery disease (PAD) samples relative to controls with an accuracy of 90%, 78%, and 85%, respectively. The compounds responsible for informative ion transitions were identified by chromatography and high resolution MS; some have been previously reported and found to be associated with coronary artery disease metabolism, indicating that the methodology generates a meaningful metabolite profile while being faster than traditional methodologies.

Exacerbation of Nanoparticle-Induced Acute Pulmonary Inflammation in a Mouse Model of Metabolic Syndrome

“…lipid profiling results via LC-MS/MS (35,(37)(38)(39)(40)(41)(42)(43)(44). Our current study only evaluated transcriptional regulation of ALOX, future studies are needed to examine protein levels and activity.…”

“…MRM-profiling was originally proposed as a twophase (discovery and screening) method based on flow injection and chemical functional profiling for small molecule biomarker discovery (34,45). It has been applied to various studies (37)(38)(39)(40)(41)(42) and here, we used the approach to interrogate the samples for MRMs related to lipid mediators reported in the literature (46)(47)(48)(49). The ion intensities yielded were compared to a blank in order to eliminate the ones that were not informative.…”

Lipidomic Profiling of the Epidermis in a Mouse Model of Dermatitis Reveals Sexual Dimorphism and Changes in Lipid Composition before the Onset of Clinical Disease

“…The composite samples were analyzed using a previously described methodology of MRM-profiling discovery experiments [ 31 ]. Briefly, neutral loss (NL) and precursor ion (Prec) scans were used to profile phospholipids, acylcarnitines (AC), sulfatides, cholesteryl esters, ceramides, glycerolipids with diverse fatty acid acyl residues, triacylglycerides, and free fatty acids in positive and negative ion modes [ 31 , 71 , 72 , 73 , 74 , 75 ]. Using a micro-autosampler (G1367A), 8 µL of the sample was directly delivered into a QQQ6410 triple quadrupole mass spectrometer (Agilent Technologies, San Jose, CA, USA) equipped with an ESI ion source.…”

Tri‐ and dipeptides identification in whey protein and porcine liver protein hydrolysates by fast LC–MS/MS neutral loss screening and de novo sequencing

“…Protonated molecules of di‐ and tripeptides should be easily screened from their selective neutral loss (NL) of 46 Da loss due to the carboxylic acid moiety 14 and could also be screened from their collision‐induced dissociation (CID) fragments by de novo sequencing 15 . NL is a structural selective scaning mode that allows selective identification of organic ions 16 . NL has been used, for instance, to analyze pooled samples to identify biomarkers in coronary arterial disease diagnosis and amorfrutin derivatives identification in real samples 17 .…”