Bile proteome analysis by high-precision mass spectrometry to examine novel biomarkers of primary sclerosing cholangitis

Host-derived protein profiles of human neonatal meconium across gestational ages

Meconium, a non-invasive biomaterial reflecting prenatal substance accumulation, could provide valuable insights into neonatal health. However, the comprehensive protein profile of meconium across gestational ages remains unclear. Here, we conducted an extensive proteomic analysis of first meconium from 259 newborns across varied gestational ages to delineate protein composition and elucidate its relevance to neonatal diseases. The first meconium samples were collected, with the majority obtained before feeding, and the mean time for the first meconium passage from the anus was 11.9 ± 9.47 h. Our analysis revealed 5370 host-derived meconium proteins, which varied depending on sex and gestational age. Specifically, meconium from preterm infants exhibited elevated concentrations of proteins associated with the extracellular matrix. Additionally, the protein profiles of meconium also exhibited unique variations depending on both specific diseases, including gastrointestinal diseases, congenital heart diseases, and maternal conditions. Furthermore, we developed a machine learning model to predict gestational ages using meconium proteins. Our model suggests that newborns with gastrointestinal diseases and congenital heart diseases may have immature gastrointestinal systems. These findings highlight the intricate relationship between clinical parameters and meconium protein composition, offering potential for a novel approach to assess neonatal gastrointestinal health.

The Clinical Utility of the Saliva Proteome in Rare Diseases: A Pilot Study for Biomarker Discovery in Primary Sclerosing Cholangitis

BACKGROUND

Primary sclerosing cholangitis (PSC) is a rare chronic inflammatory liver disease characterized by biliary strictures and cholestasis. Due to the lack of effective serological indicators for diagnosis and prognosis, in the present study, we examined the potentiality of the saliva proteome to comprehensively screen for novel biomarkers.

METHODS

Saliva samples of PSC patients and healthy controls were processed and subsequently analyzed using a liquid chromatography-tandem mass spectrometry technique. A bioinformatic approach was applied to detect the differentially expressed proteins, their related biological functions and pathways, and the correlation with the clinical evidence in order to identify a possible marker for the PSC group.

RESULTS

We identified 25 differentially expressed proteins in PSC patients when compared to the healthy control group. Among them, eight proteins exhibited area under the curve values up to 0.800, suggesting these saliva proteins as good discriminators between the two groups. Multiple positive correlations were also identified between the dysregulated salivary proteins and increased serum alkaline phosphatase levels and the presence of ulcerative colitis. Pathway analysis revealed significant enrichments in the immune system, neutrophil degranulation, and in the interleukine-17 signaling pathway.

CONCLUSION

We demonstrated the potentiality of saliva as a useful biofluid to obtain a fingerprint of the pathology, suggesting disulfide-isomerase A3 and peroxiredoxin-5 as the better discriminating proteins in PSC patients. Hence, analysis of saliva proteins could become, in future, a useful tool in the screening of patients with suspected PSC.

Development of a Simple and Stable NanoESI Spray System Using Suction Wind from the MS Inlet

Improving the reproducibility of proteome analysis systems presents a challenge; therefore, in this study, we developed a new insertion spray ionization (InSpIon) system wherein an InSpIon tube was designed with a spray tip inserted into the tube. This system stabilized the spray and subsequently improved the reproducibility of the analysis.