Trioxidized cysteine and aging: a molecular binomial that extends far beyond classical proteinopathic paradigms.

Increased oxidative stress (OS) and the disruption of the equilibrium between the production of reactive oxygen species and antioxidants are key molecular features of unhealthy aging. OS results in the formation of oxidative posttranslational modifications (PTMs), some of which involve cysteine (Cys) residues in aging proteomes, and specifically, the formation of trioxidized Cys (t-Cys), which leads to permanent protein damage. Recent findings in rodents have uncovered that irregular regulation of t-Cys residues in the aging proteome disrupts homeostatic phosphorylation signaling, resulting in alterations to proteins that are analogous to those caused by phosphorylated serine (p-Ser) residues. This work contextualizes these significant findings and discusses the implications and molecular role(s) of t-Cys in the aging proteome. Furthermore, we present novel data, validating the increase of specific t-Cys sites associated with aging in a blood-related circulating human proteome. The scope and findings included here support the hypothesis that t-Cys residues may serve as important mechanistic and biological markers, warranting further exploration in the context of unhealthy aging and age-related major diseases.

Trioxidized cysteine in the aging proteome mimics the structural dynamics and interactome of phosphorylated serine.

Aging is the primary risk factor for the development of numerous human chronic diseases. On a molecular level, it significantly impacts the regulation of protein modifications, leading to the accumulation of degenerative protein modifications (DPMs) such as aberrant serine phosphorylation (p-Ser) and trioxidized cysteine (t-Cys) within the proteome. The altered p-Ser is linked to abnormal cell signaling, while the accumulation of t-Cys is associated with chronic diseases induced by oxidative stress. Despite this, the potential cross-effects and functional interplay between these two critical molecular factors of aging remain undisclosed. This study analyzes the aging proteome of wild-type C57BL/6NTac mice over 2 years using advanced proteomics and bioinformatics. Our objective is to provide a comprehensive analysis of how t-Cys affects cell signaling and protein structure in the aging process. The results obtained indicate that t-Cys residues accumulate in the aging proteome, interact with p-Ser interacting enzymes, as validated in vitro, and alter their structures similarly to p-Ser. These findings have significant implications for understanding the interplay of oxidative stress and phosphorylation in the aging process. Additionally, they open new venues for further research on the role(s) of these protein modifications in various human chronic diseases and aging, wherein exacerbated oxidation and aberrant phosphorylation are implicated.

Next-Generation Proteomics of Brain Extracellular Vesicles in Schizophrenia Provide New Clues on the Altered Molecular Connectome.

Extracellular vesicles (EVs) are tiny membranous structures that mediate intercellular communication. The role(s) of these vesicles have been widely investigated in the context of neurological diseases; however, their potential implications in the neuropathology subjacent to human psychiatric disorders remain mostly unknown. Here, by using next-generation discovery-driven proteomics, we investigate the potential role(s) of brain EVs (bEVs) in schizophrenia (SZ) by analyzing these vesicles from the three post-mortem anatomical brain regions: the prefrontal cortex (PFC), hippocampus (HC), and caudate (CAU). The results obtained indicate that bEVs from SZ-affected brains contain region-specific proteins that are associated with abnormal GABAergic and glutamatergic transmission. Similarly, these vesicles from the analyzed regions were implicated in synaptic decay, abnormal brain immunity, neuron structural imbalances, and impaired cell homeostasis. Our findings also provide evidence, for the first time, that networks of molecular exchange (involving the PFC, HC, and CAU) are potentially active and mediated by EVs in non-diseased brains. Additionally, these bEV-mediated networks seem to have become partially reversed and largely disrupted in the brains of subjects affected by SZ. Taken as a whole, these results open the door to the uncovering of new biological markers and therapeutic targets, based on the compositions of bEVs, for the benefit of patients affected by SZ and related psychotic disorders.

Altered ureido protein modification profiles in seminal plasma extracellular vesicles of non-normozoospermic men.

Introduction: Extracellular vesicles (EVs) have been recognized as key players in numerous physiological functions. These vesicles alter their compositions attuned to the health and disease states of the organism. In men, significant changes in the proteomic composition(s) of seminal plasma EVs (sEVs) have already been found to be related to infertility. Methods: Methods: In this study, we analyze the posttranslational configuration of sEV proteomes from normozoospermic (NZ) men and non-normozoospermic (non-NZ) men diagnosed with teratozoospermia and/or asthenozoospermia by unbiased, discovery-driven proteomics and advanced bioinformatics, specifically focusing on citrulline (Cit) and homocitrulline (hCit) posttranscriptional residues, both considered product of ureido protein modifications. Results and discussion: Significant increase in the proteome-wide cumulative presence of hCit together with downregulation of Cit in specific proteins related to decisive molecular functions have been encountered in sEVs of non-NZ subjects. These findings identify novel culprits with a higher chance of affecting fundamental aspects of sperm functional quality and define potential specific diagnostic and prognostic non-invasive markers for male infertility.

Differential systemic decellularization in vivo to study molecular changes in each vasculature layer in murine models of disease.

Vascular dysfunction underlies the onset and progression of many life-threatening diseases, highlighting the need for improved understanding of its molecular basis. Here, we present differential systemic decellularization in vivo (DISDIVO), a protocol that enables systemic and independent study of the molecular changes in each vasculature layer in murine models of disease. We describe steps for anesthesia, perfusion surgery, and exsanguination. We then detail detachment and collection of glycocalyx and decellularization and collection of both endothelial and smooth muscle cells. For complete details on the use and execution of this protocol, please refer to Serra et al., Gallart-Palau et al., and Vinaiphat et al.1,2,3.