From micellar electrokinetic chromatography to liquid chromatography-mass spectrometry: Revisiting the way of analyzing human fluids for the search of desmosines, putative biomarkers of chronic obstructive pulmonary disease

The Benefit of Hydrogen Gas as an Adjunctive Therapy for Chronic Obstructive Pulmonary Disease

Background and Objectives: Recent studies suggest that hydrogen gas possesses anti-inflammatory, antioxidant, and anti-apoptotic properties. This study aimed to explore the therapeutic potential of hydrogen gas and assess its safety and tolerability in individuals with chronic obstructive pulmonary disease (COPD). Materials and Methods: Enrolled COPD patients received standard treatments along with additional hydrogen inhalation for 30 min in the morning, afternoon, and evening over a 30-day period. The assessment included changes in the COPD Assessment Test (CAT), the modified Medical Research Council (mMRC) Dyspnea Scale, lung function, sleep quality, inflammation markers, and oxidative stress markers before and after hydrogen inhalation. Results: Six patients participated in this study. Patients 2, 3, 4, 5, and 6 demonstrated improvements in CAT scores following hydrogen gas intervention, with patients 2, 4, 5, and 6 also showing improvements in mMRC scores. Statistically, this study revealed significant improvements in CAT [15.5 (10.5-19.75) vs. 8.5 (3-13.5); p = 0.043] and mMRC scores [2.5 (1-4) vs. 2 (0-3.25); p = 0.046] before and after intervention, respectively. However, no significant differences were observed in lung function, DLCO, sleep quality, and 6 MWT before and after hydrogen therapy. CBC examination showed a significant difference in platelet count before and after treatment [247 (209.75-298.75) vs. 260 (232.75-314.5); p = 0.043], respectively, while other blood tests, inflammation markers, and oxidative stress markers did not exhibit significant differences before and after hydrogen therapy. All patients experienced no obvious side-effects. Conclusions: Adjuvant therapy with hydrogen gas demonstrated symptom improvements in specific COPD patients, and no significant adverse effects were observed in any of the patients. Hydrogen gas may also exert a modulatory effect on platelet count.

Searching for biomarkers of chronic obstructive pulmonary disease using proteomics: The current state

Detection of proteins which may be potential biomarkers of disorders represents a big step forward in understanding the molecular mechanisms that underlie pathological processes. In this context proteomics plays the important role of opening a path for the identification of molecular signatures that can potentially assist in early diagnosis of several clinical disturbances. Aim of this report is to provide an overview of the wide variety of proteomic strategies that have been applied to the investigation of chronic obstructive pulmonary disease (COPD), a severe disorder that causes an irreversible damage to the lungs and for which there is no cure yet. The results in this area published over the past decade show that proteomics indeed has the ability of monitoring alterations in expression profiles of proteins from fluids/tissues of patients affected by COPD and healthy controls. However, these data also suggest that proteomics, while being an attractive tool for the identification of novel pathological mediators of COPD, remains a technique mainly generated and developed in research laboratories. Great efforts dedicated to the validation of these biological signatures will result in the proof of their clinical utility.

Recent applications of CE- and HPLC-MS in the analysis of human fluids

The present review intends to cover the literature on the use of CE-/LC-MS for the analysis of human fluids, from 2010 until present. It has been planned to provide an overview of the most recent practical applications of these techniques to less extensively used human body fluids, including, bronchoalveolar lavage fluid, synovial fluid, nipple aspirate, tear fluid, breast fluid, amniotic fluid, and cerumen. Potential pitfalls related to fluid collection and sample preparation, with particular attention to sample clean-up procedures, and methods of analysis, from the research laboratory to a clinical setting will also be addressed. While being apparent that proteomics/metabolomics represent the most prominent approaches for global identification/quantification of putative biomarkers for a variety of human diseases, evidence is also provided of the suitability of these sophisticated techniques for the detection of heterogeneous components carried by these fluids.

Fingerprinting desmosine-containing elastin peptides

Elastin is a vital protein of the extracellular matrix of jawed vertebrates and provides elasticity to numerous tissues. It is secreted in the form of its soluble precursor tropoelastin, which is subsequently cross-linked in the course of the elastic fiber assembly. The process involves the formation of the two tetrafunctional amino acids desmosine (DES) and isodesmosine (IDES), which are unique to elastin. The resulting high degree of cross-linking confers remarkable properties, including mechanical integrity, insolubility, and long-term stability to the protein. These characteristics hinder the structural elucidation of mature elastin. However, MS(2) data of linear and cross-linked peptides released by proteolysis can provide indirect insights into the structure of elastin. In this study, we performed energy-resolved collision-induced dissociation experiments of DES, IDES, their derivatives, and DES-/IDES-containing peptides to determine characteristic product ions. It was found that all investigated compounds yielded the same product ion clusters at elevated collision energies. Elemental composition determination using the exact masses of these ions revealed molecular formulas of the type CxHyN, suggesting that the pyridinium core of DES/IDES remains intact even at relatively high collision energies. The finding of these specific product ions enabled the development of a similarity-based scoring algorithm that was successfully applied on LC-MS/MS data of bovine elastin digests for the identification of DES-/IDES-cross-linked peptides. This approach facilitates the straightforward investigation of native cross-links in elastin.