Multifactorial analysis of affinity-mass spectrometry data from serum protein samples: A strategy to distinguish patients with preeclampsia from matching control individuals

Abstract

A multifactorial differential analysis of serum proteins using mass spectrometry distinguished samples from pregnant women with severe early-onset preeclampsia (n ϭ 11) from those of control individuals with uneventful pregnancies (n ϭ 13). Serum proteins were fractionated by either their affinities to reversed-phase material coated magnetic beads or by fractionated precipitation. The on-average most abundant ion signals were observed at m/z 9390, 9103, and 8886. The best differentiating ion signals between the two sample groups were found at m/z 13,715, 13,834, and 13,891. The normalized intensities of these ion signals were on-average lower in the preeclampsia group than in the control group. The six ion signal intensities enabled sorting of the individual spectra with high accuracy. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis showed that a protein band migrating just above the 14 kDa marker band contained transthyretin (P02766; M r (avg.): 13,761). Densitometric analysis of the transthyretin bands showed lower intensities in the preeclampsia samples with respect to those of the controls. Nephelometric analysis of the serum samples determined the mean concentration of transthyretin in the preeclampsia group were lower (0.16 mg/mL; range: 0.13 to 0.20; SD: 0.03) than that in the control group (0.19 mg/mL; range: 0.14 to 0.22; SD: 0.02), substantiating the role of transthyretin concentration differences in the comparison of the two groups. Altogether, our findings support the theory of preeclampsia being a heterogeneous disorder that might be sub-classified by a defined proteome signature in maternal blood using multifactorial analysis of affinity-fractionated serum samples. (J Am

Mass spectrometric characterization of limited proteolysis activity in human plasma samples under mild acidic conditions

“…44/1933.99 were formed and the resulting ratio values were determined for each time point. Double measurements were averaged and standard deviations were calculated as previously reported [12]. The Origin statistics software (version.…”

“…With the ability to investigate multiple plasma protein abundances in parallel, mass spectrometry has become an attractive approach for studying such precious clinical samples [11,12]. Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI ToF MS) is an advanced technique that can detect hundreds of peptide and/or protein ion signals from body fluids in one measurement with good reproducibility and robustness.…”

“…Hence, MALDI ToF MS has enabled the multi-parametric analysis of the reservoir of proteins derived from high-abundant endogenous circulating molecules. Plasma proteome profile analyses by mass spectrometry encompass determination of abundance differences of intact plasma proteins using affinity-enrichment methods in combination with MALDI mass spectrometry [12][13][14][15]. Since mass spectrometric protein analyses are capable to monitor dynamic changes of protein/peptide abundances in plasma they are ideal for discovery of novel biomarkers.…”

Placenta related pathogenic factors for preeclampsia

“…TTR secreted from placenta has been proved to play crucial role in transference of maternal thyroid hormone to the fetal circulation though TTR-T4 complex for fetus development [43]. According to the recent researches, TTR was found decreased in maternal serum of women with PE [44,45]. As the central pathology changes in PE, placenta necrosis could lead to decrease secretion of TTR, which might result in disorders of fetus development in severe PE.…”

Proteomics translational

“…Von diesen Proteinen wurde -ebenfalls über Proteomuntersuchungen -in der Hälfte der Fälle eine Assoziation mit HDL-Partikeln aufgedeckt [32]. In eigenen Untersuchungen nutzten wir die MALDI-TOF-Massenspektrometrie zur Serumanalyse bei Prä-eklampsie [26] und erstellten einen Algorithmus, nach dem die Präeklampsie-patientinnen von gesunden Kontrollen unterschieden werden kann. Wir konnten darlegen, dass es sich bei den so erhaltenen Peaks um ein präeklampsiespe-zifisches multifaktorielles SerumproteinExpressionsmuster handelt (.…”