Peptidomics analysis reveals changes in small urinary peptides in patients with interstitial cystitis/bladder pain syndrome

Abstract

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a chronic and debilitating pain disorder of the bladder and urinary tract with poorly understood etiology. A definitive diagnosis of IC/BPS can be challenging because many symptoms are shared with other urological disorders. An analysis of urine presents an attractive and non-invasive resource for monitoring and diagnosing IC/BPS. The antiproliferative factor (APF) peptide has been previously identified in the urine of IC/BPS patients and is a proposed biomarker for the disorder. Nevertheless, other small urinary peptides have remained uninvestigated in IC/BPS primarily because protein biomarker discovery efforts employ protocols that remove small endogenous peptides. The purpose of this study is to investigate the profile of endogenous peptides in IC/BPS patient urine, with the goal of identifying putative peptide biomarkers. Here, a non-targeted peptidomics analysis of urine samples collected from IC/BPS patients were compared to urine samples from asymptomatic controls. Our results show a general increase in the abundance of urinary peptides in IC/BPS patients, which is consistent with an increase in inflammation and protease activity characteristic of this disorder. In total, 71 peptides generated from 39 different proteins were found to be significantly altered in IC/BPS. Five urinary peptides with high variable importance in projection (VIP) coefficients were found to reliably differentiate IC/BPS from healthy controls by receiver operating characteristic (ROC) analysis. In parallel, we also developed a targeted multiple reaction monitoring method to quantify the relative abundance of the APF peptide from patient urine samples. Although the APF peptide was found in moderately higher abundance in IC/BPS relative to control urine, our results show that the APF peptide was inconsistently present in urine, suggesting that its utility as a sole biomarker of IC/BPS may be limited. Overall, our results revealed new insights into the profile of urinary peptides in IC/BPS that will aid in future biomarker discovery and validation efforts.

Peptidomic Analysis Reveals Seasonal Neuropeptide and Peptide Hormone Changes in the Hypothalamus and Pituitary of a Hibernating Mammal

“…Endogenous peptides were extracted from tissues using both organic and aqueous extraction steps and enriched using molecular weight-based centrifugation filtration devices and solid-phase extraction. Extracted peptides were analyzed by a LC–MS and LC–MS/MS-based label-free peptidomics workflow, , which includes steps for data filtering, batch correction, imputation, and normalization (Figures S2–S5). Following data processing and normalization, relative peptide abundances were compared between groups using multivariate and univariate statistical analyses.…”

“…We hypothesized that changes in cell–cell signaling peptides from the hypothalamus and pituitary may be responsible for regulating critical physiological changes during the hibernation season. To test this hypothesis, we applied a non-targeted liquid chromatography–mass spectrometry (LC–MS) and LC-tandem mass spectrometry (LC–MS/MS) “peptidomics” approach ,− to identify and quantify endogenous neuropeptides and peptide hormones as a function of season and hibernation stage in the thirteen-lined ground squirrel. LC–MS and LC–MS/MS-based peptidomics allow the detection, identification, and quantification of peptides without preselection, allowing for findings not possible with targeted antibody-based methods.…”

Peptidomic analysis of endogenous and bacterial protease activity in human plasma and wound fluids

“…Indeed, endogenous peptides may serve as biomarkers in a range of diseases. 60 , 61 , 62 , 63 To investigate the possibility of using peptides as biomarkers for wound status, we previously developed a mass spectrometry-based method to measure the low-molecular-weight peptidome of wound fluids and used this method to identify unique peptides and patterns that differed between healing/non-infected and inflamed/infected wounds. 25 , 26 As individual proteases have different substrate specificities, and will result in peptides with enzyme specific sequences, the observed differences may be explained by the level and nature of individual proteases in these wounds, which may have additional diagnostic/prognostic value.…”

Untargeted Metabolomics Pilot Study Using UHPLC-qTOF MS Profile in Sows’ Urine Reveals Metabolites of Bladder Inflammation

“…It is well known that UTI represent a problem for the subsequent reproductive performance [1][2][3]7] in sows. There is a very recent study on novel protein biomarkers of UTI in children [47] and emerging studies on the biomarkers of interstitial cystitis/bladder pain syndrome (IC/BPS) [48][49][50]. These developments highlight that abnormal expressions of several urine and serum specimens, including oxidative stress biomarkers (8-OHdG, 8-isoprostane, and total antioxidant capacity) [51]; growth factor; methylhistamine; glycoprotein; and chemokine and cytokines, may all be useful as biomarkers for the purposes of IC/BPS diagnosis, as reviewed here [52].…”