Biology subjects

Diaz Ludovico, I.

Publications and source records attributed to Diaz Ludovico, I..

7 recordsLinked to original sources

bioRxiv2026

Carbamylome analysis reveals regulatory roles for lysine carbamylation in β-cell glycolytic and insulin-processing enzymes

In type 1 diabetes (T1D), insulin-producing {beta} cells are destroyed by an autoimmune response driven by pro-inflammatory cytokines, including interferons. {beta}-cell cytokine signaling is mediated in part by post-translational modifications, such as phosphorylation and acetylation. However, the role of other post-translational modifications in {beta}-cell cytokine signaling represents an important knowledge gap. In the context of autoimmune diseases, lysine carbamylation has gained attention for its role in pathogenesis. Here, we investigate the role of carbamylation in T1D. We found that pancreatic islet cells from the T1D model, non-obese diabetic (NOD) mice, exhibit 11% carbamylation-positive cells, whereas non-diabetic CD1 mice have only 5%. Proteomics analysis of the MIN6 insulin-producing cell line treated with a cocktail of three pro-inflammatory cytokines IFN{gamma} + IL-1{beta} + TNF identified 284 carbamylated peptides from 222 proteins impacted by the cytokine treatment. Integration of carbamylation and acetylation provided a deep view of the cytokine-regulated PTMs and potential points of interplay. A functional-enrichment analysis revealed that carbamylation was enriched in pathways related to autoimmune diseases, metabolism, DNA replication, and protein translation. Moreover, functional testing demonstrated that carbamylation inhibits the glycolytic enzyme aldolase A and the insulin-processing enzyme carboxypeptidase E, identifying a possible role for cytokine-induced {beta}-cell dysfunction. In summary, protein carbamylation is elevated in islets from NOD mice, and pro-inflammatory cytokine treatment regulates protein carbamylation in MIN6 cells. These data identify carbamylation as a potential regulatory mechanism for {beta}-cell metabolism and insulin production in the context of islet inflammation.

biochemistry↗

bioRxiv2026

Unbiased proteomics following inflammasome activation identifies caspase targets in primary intestinal epithelial cells

Inflammasomes are cytosolic innate immune sensors that, once activated by a pathogenic threat, lead to activation of the inflammatory Caspase-1. Inflammasome activation and its consequences have been studied extensively in myeloid cells and in overexpression systems. Recent studies have identified cell type specific effects that are not fully explained by the known cleavage targets of Caspase-1. Here, we identified targets of caspase cleavage using mass spectrometry in primary intestinal epithelial cells by specifically activating the NAIP-NLRC4 inflammasome. We have taken an unbiased approach and developed a novel method for analyzing mass spectrometry data for evidence of caspase activity. Our approach can also be applied to existing proteomic datasets to establish the presence of caspase activity under various biological conditions. These results lay the groundwork for future studies on mechanisms of caspase-induced processes such as intestinal epithelial cell extrusion.

immunology↗

bioRxiv2026

Assessing extracellular vesicle proteins as predictive biomarkers for developing type 1 diabetes

Plasma extracellular vesicles (EVs) are considered excellent sources for biomarker discovery since they carry signatures of their cellular origin and disease processes. In this paper, we evaluate the potential of plasma EV proteomics analysis for identifying predictive biomarkers of developing type 1 diabetes (T1D), which results from autoimmune destruction of insulin-producing {beta} cells in the islet. We used strong anion exchange beads (Mag-Net) to capture plasma EVs from 19 donors with islet autoimmunity (diagnosed by circulating autoantibodies against islet proteins - AAB+) vs. 17 control individuals and analyzed their protein cargo by mass spectrometry. The analysis identified and quantified 5,480 proteins, a 3.2-fold increase in proteome coverage compared to our previous T1D biomarker proteomics study that used whole plasma depleted of the 14 most abundant proteins. The Mag-Net approach also detected 1,306 out of the 1,717 proteins (76%) that we previously verified as EV proteins. Statistical tests revealed 448 proteins to be differentially abundant in AAB+ vs control volunteers, including 69 previously verified EV proteins. A functional-enrichment analysis resulted in overrepresentation of 25 pathways among the differentially abundant proteins, including pathways related to autoimmune response and lipid metabolism. The capacity of this data to predict AAB+ was tested with a machine learning analysis using a random forest model, resulting in a receiver operating characteristic-area under the curve of 0.81. Overall, our study indicates that plasma EV proteomics analysis can be an exciting approach for studying biomarkers for developing T1D. Significance of the studyType 1 diabetes (T1D) is a disease characterized by the bodys inability to produce insulin and consequently, to control blood glucose levels. Despite the initial trigger being unclear, the disease development process involves an autoimmune response to the islets of Langerhans, resulting in the death of insulin-producing {beta} cells. There is no cure for the disease, and treatment relies on exogenous administration of insulin. Therefore, preventive therapies that block the autoimmune process are attractive for treating T1D. In fact, anti-CD3 antibody (Teplizumab) delays the onset of T1D by 2 years by targeting T cells. Predictive biomarkers for developing T1D are needed to aid the development and implementation of new therapies and to identify the initial trigger and mechanisms of the islet autoimmune process. In this paper, we assess the potential of plasma extracellular vesicle (EV) proteomics analysis for identifying predictive biomarkers of T1D. Our results show excellent potential of the approach, opening opportunities to perform broader studies to identify biomarkers for developing T1D.

systems biology↗

bioRxiv2025

Sexually distinct multi omic responses to progressive endurance exercise training in the rat lung. Findings from MoTrPAC

Despite the lungs being essential for ventilation and aerobic exercise capacity, conventionally the lungs are not thought to adapt to exercise training. Endurance exercise is key to pulmonary rehabilitation programs, which also displays sex-specific differences in therapeutic efficacy. Given the molecular underpinnings of sex-specific lung adaptations to endurance exercise are uncharacterized, we used a multi-omics approach to study sex differences in the lungs of 6-month-old Fischer 344 rats in response to an 8 week progressive endurance treadmill training protocol. This was accomplished by reannotating publicly accessible data from the Molecular Transducers of Physical Activity Consortium (MoTrPAC) and integrating newly-analyzed acetylome data to assess multi-omic sex differences in sedentary and progressively trained states. Female rats displayed enrichment in immune-related features and pathways at the transcriptome and proteome level that were maintained with training. Conversely, in the male rat lung there was an overall decrease in immune pathways following 8 weeks of training. Sexually conserved responses to training included increased enrichment in transcriptomic pathways related to type I alveoli and proteomic pathways related to cilia, and decreased mitochondrial protein acetylation. In both sexes, features known to be enriched in lung diseases were attenuated with training. Together our findings provide novel insight into sex specific responses to endurance exercise training in the rat lung and may offer translational insight into sex-specific differences in lung disease pathogenesis and treatment.

physiology↗

bioRxiv2024

A fast and sensitive size-exclusion chromatography method for plasma extracellular vesicle proteomic analysis

Extracellular vesicles (EVs) carry diverse biomolecules derived from their parental cells, making their components excellent biomarker candidates. However, purifying EVs is a major hurdle in biomarker discovery since current methods require large amounts of samples, are time-consuming and typically have poor reproducibility. Here we describe a simple, fast, and sensitive EV fractionation method using size exclusion chromatography (SEC) on a fast protein liquid chromatography (FPLC) system. Our method uses a Superose 6 Increase 5/150, which has a bed volume of 2.9 mL. The FPLC system and small column size enable reproducible separation of only 50 {micro}L of human plasma in 15 minutes. To demonstrate the utility of our method, we used longitudinal samples from a group of individuals that underwent intense exercise. A total of 838 proteins were identified, of which, 261 were previously characterized as EV proteins, including classical markers, such as cluster of differentiation (CD)9 and CD81. Quantitative analysis showed low technical variability with correlation coefficients greater than 0.9 between replicates. The analysis captured differences in relevant EV-proteins involved in response to physical activity. Our method enables fast and sensitive fractionation of plasma EVs with low variability, which will facilitate biomarker studies in large clinical cohorts.

biochemistry↗

bioRxiv2020

Dataset of the construction and characterization of stable biological nanoparticles

We suggest that the structural flexibility is key for certain proteins in order to fulfill functions that are required to interact with biological membranes, and that intra-chain chemical crosslinking may result in a different arrangement of protein with lipids. As interaction with biological membranes and lipids is a function attributed to many proteins in circulation, we intended to characterize an experimental design that helps in the study of many biological protein structures and their function. But in addition, by introducing intra-chain crosslinking, we obtained discoidal nano platforms that are stable under different conditions of temperate and time incubation. These platforms might be an excellent model to employ as biological carriers of intrinsic or external molecules. Thus, data shown here clearly strengthen the usefulness of an easy, accessible and inexpensive tool not only to study protein-lipid interactions, but to be used in different biological fields that require the transport of organic compounds.

biophysics↗

bioRxiv2020

Understanding the role of apolipoprotein A-I in atherosclerosis. Post-translational modifications synergize dysfunction?

BackgroundThe identification of dysfunctional human apolipoprotein A-I (apoA-I) in atherosclerotic plaques suggests that protein structure and function may be hampered under a chronic pro inflammatory scenario. Moreover, the fact that natural mutants of this protein elicit severe cardiovascular diseases (CVD) strongly indicates that the native folding could shift due to the mutation, yielding a structure more prone to misfold or misfunction. To understand the events that determine the failure of apoA-I structural flexibility to fulfill its protective role, we took advantage of the study of a natural variant with a deletion of the residue lysine 107 (K107del) associated with atherosclerosis. MethodsBiophysical approaches, such as electrophoresis, fluorescence and spectroscopy were used to characterize proteins structure and function, either in the native conformation or under oxidation or intramolecular crosslinking. ResultsK107del structure was more flexible than the protein with the native sequence (Wt) but interactions with artificial membranes were preserved. Instead, structural restrictions by intramolecular crosslinking impaired the Wt and K107del lipid solubilization function. In addition, controlled oxidation decreased the yield of the native dimer conformation for both variants. ConclusionsWe conclude that even though mutations may alter protein structure and spatial arrangement, the highly flexible conformation compensates the mild shift from the native folding. Instead, post translational apoA-I modifications (probably chronic and progressive) are required to raise a protein conformation with significant loss of function and increased aggregation tendency. General SignificanceThe results learnt from this variant strength a close association between amyloidosis and atherosclerosis. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=95 SRC="FIGDIR/small/142844v1_ufig1.gif" ALT="Figure 1"> View larger version (18K): org.highwire.dtl.DTLVardef@265244org.highwire.dtl.DTLVardef@1e30814org.highwire.dtl.DTLVardef@279375org.highwire.dtl.DTLVardef@421fd9_HPS_FORMAT_FIGEXP M_FIG C_FIG Highlights-Oxidation is clue to induce protein misfolding -Natural mutation does not seem critical as a sole reason to determine pathogenicity -Atherosclerosis and amyloidosis are closely related -Intramolecular crosslinking restrains protein flexibility and function

biophysics↗