Govorukhina, N. | Search bioRxiv

bioRxiv2025

It takes two: Aberrant repair and low-grade inflammation characterizes bronchiolitis obliterans syndrome after lung transplantation in serum proteomic analysis

AimThe obstructive phenotype of chronic lung allograft dysfunction, bronchiolitis obliterans syndrome (BOS), is diagnosed after lung transplantation (LTx) when irreversible airway obstruction is already present. This study aimed to investigate the fibrotic response and inflammation signals in serum of BOS patients. MethodsLTx patients transplanted at the University Medical Center Groningen between 2004 and 2017 were screened. Nineteen patients with BOS were selected and matched to 19 non-BOS patients. Only patients for whom lung function and longitudinal serum samples post-LTx were available were included. Enzyme-linked immunosorbent assays were performed for neoepitopes of collagen types I, III, and VI and osteoprotegerin (OPG) in serum. Additionally, serum samples were analyzed by label free liquid chromatography with tandem mass spectrometry proteomics analysis. ResultsCollagen neoepitopes did not differ significantly between BOS and non-BOS patients at any timepoint. OPG was significantly higher in non-BOS compared to BOS six months before BOS onset (p<0.04). In proteomics analysis, proteins indicating cell repair and proliferation, namely human type II keratin-6 and centromere protein F (both FDR<0.1), were significantly lower three months before BOS onset in BOS compared to non-BOS patients. C-reactive protein (FDR<0.05) and SERPINA3 (FDR<0.05) amongst others, were higher in end-stage BOS compared to non-BOS patients. ConclusionDifferences in expression of proteins that reflect the complex interplay between fibrosis and inflammation in BOS were identified. These proteins should be investigated and validated in larger cohorts and may aid in expanding knowledge about the development of BOS.

bioinformatics↗

bioRxiv2022

Comparative assessment of quantification methods for tumor tissue phosphoproteomics

With increasing sensitivity and accuracy in mass spectrometry, the tumor phosphoproteome is getting into reach. However, the selection of quantitation techniques best-suited to the biomedical question and diagnostic requirements remains a trial and error decision as no study has directly compared their performance for tumor tissue phosphoproteomics. We compared label-free quantification (LFQ), spike-in-SILAC (stable isotope labeling by amino acids in cell culture) and TMT isobaric tandem mass tags technology for quantitative phosphosite profiling in tumor tissue. TMT offered the lowest accuracy and the highest precision and robustness towards different phosphosite abundances and matrices. Spike-in-SILAC offered the best compromise between these features but suffered from a low phosphosite coverage. LFQ offered the lowest precision but the highest number of identifications. Both spike-in-SILAC and LFQ presented susceptibility to matrix effects. Match between run (MBR)-based analysis enhanced the phosphosite coverage across technical replicates in LFQ and spike-in-SILAC but further reduced the precision and robustness of quantification. The choice of quantitative methodology is critical for both study design such as sample size in sample groups and quantified phosphosites, and comparison of published cancer phosphoproteomes. Using ovarian cancer tissue as an example, our study builds a resource for the design and analysis of quantitative phosphoproteomic studies in cancer research and diagnostics.

biochemistry↗