Peptidylarginine deiminases and extracellular vesicles: prospective drug targets and biomarkers in central nervous system diseases and repair.

Peptidylarginine deiminases are a family of calcium-activated enzymes with multifaceted roles in physiological and pathological processes, including in the central nervous system. Peptidylarginine deiminases cause post-translational deimination/citrullination, leading to changes in structure and function of a wide range of target proteins. Deimination can facilitate protein moonlighting, modify protein-protein interaction, cause protein dysfunction and induce inflammatory responses. Peptidylarginine deiminases also regulate the biogenesis of extracellular vesicles, which play important roles in cellular communication through transfer of extracellular vesicle-cargo, e.g., proteins and genetic material. Both peptidylarginine deiminases and extracellular vesicles are linked to a number of pathologies, including in the central nervous system, and their modulation with pharmacological peptidylarginine deiminase inhibitors have shown great promise in several in vitro and in vivo central nervous system disease models. Furthermore, extracellular vesicles derived from mesenchymal stem cells have been assessed for their therapeutic application in central nervous system injury. As circulating extracellular vesicles can be used as non-invasive liquid biopsies, their specific cargo-signatures (including deiminated proteins and microRNAs) may allow for disease "fingerprinting" and aid early central nervous system disease diagnosis, inform disease progression and response to therapy. This mini-review discusses recent advances in the field of peptidylarginine deiminase and extracellular vesicle research in the central nervous system, focusing on several central nervous system acute injury, degeneration and cancer models

Animal Models of Human Disease

© 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).The use of animal models of human disease is critical for furthering our understanding of disease mechanisms, for the discovery of novel targets for treatment, and for translational research. This Special Topic entitled “Animal Models of Human Disease” aimed to collect state-of-the-art primary research studies and review articles from international experts and leading groups using animal models to study human diseases. Submissions were welcomed on a wide range of animal models and pathologies, including infectious disease, acute injury, regeneration, cancer, autoimmunity, degenerative and chronic disease. Seven participating MDPI journals supported the Special Topic, namely: Biomedicines, Cells, Current Issues in Molecular Biology, Diagnostics, Genes, the International Journal of Molecular Sciences, and the International Journal of Translational Medicine. In total, 46 papers were published in this Special Topic, with 37 full length original research papers, 2 research communications and 7 reviews. These contributions cover a wide range of clinically relevant, translatable, and comparative animal models, as well as furthering understanding of fundamental sciences, covering topics on physiological processes, on degenerative, inflammatory, infectious, autoimmune, neurological, metabolic, heamatological, hormonal and mitochondrial disorders, developmental processes and diseases, cardiology, cancer, trauma, stress, and ageing.Peer reviewe

Animal models of human disease

The use of animal models of human disease is critical for furthering our understanding of disease mechanisms, for the discovery of novel targets for treatment, and for translational research. This Special Topic entitled “Animal Models of Human Disease” aimed to collect state-of-the-art primary research studies and review articles from international experts and leading groups using animal models to study human diseases. Submissions were welcomed on a wide range of animal models and pathologies, including infectious disease, acute injury, regeneration, cancer, autoimmunity, degenerative and chronic disease. Seven participating MDPI journals supported the Special Topic, namely: Biomedicines, Cells, Current Issues in Molecular Biology, Diagnostics, Genes, the International Journal of Molecular Sciences, and the International Journal of Translational Medicine. In total, 46 papers were published in this Special Topic, with 37 full length original research papers, 2 research communications and 7 reviews. These contributions cover a wide range of clinically relevant, translatable, and comparative animal models, as well as furthering understanding of fundamental sciences, covering topics on physiological processes, on degenerative, inflammatory, infectious, autoimmune, neurological, metabolic, heamatological, hormonal and mitochondrial disorders, developmental processes and diseases, cardiology, cancer, trauma, stress, and ageing

A novel ladder-like lectin relates to sites of mucosal immunity in Atlantic Halibut (Hippoglossus hippoglossus L.)

A novel 27 kDa ladder-lectin-like protein, showing a multimeric structure under non-reducing conditions, was isolated from halibut serum by binding to N-acetyl glucosamine. Mass-spectrometry analysis did not show significant homology with known proteins. Specific antibodies were produced and used in immunohistochemistry on tissue sections of early halibut ontogeny from 119 until 1050 °d post hatching. A strong positive response was detected in the mucosal cells of the skin, gills and gut, indicating a role in the mucosal immune defence at these sites. Further immunopositivity was detected in liver, myeloma of kidney and the brain at different developmental stages but predominant expression was found in mucosal surfaces at later stages of development tested (1050 °d). It is still uncertain whether this ladder-like lectin forms part of the complement pathway, as a lectin or ficolin, or if it belongs to galectins. A strong detection in mucosal surfaces on skin, gills and gut, show similar patterns of expression as both mucosal lectins and galectins in other fish. Detection in neuronal tissue may indicate putative roles in tissue remodelling of brain and in ongoing neurogenesis in the fish eye

Peptidylarginine Deiminase Inhibition Abolishes the Production of Large Extracellular Vesicles From

is a microaerophilic protozoan that is an important etiologic agent of diarrhea worldwide. There is evidence that under diverse conditions, the parasite is capable of shedding extracellular vesicles (EVs) which modulate the physiopathology of giardiasis. Here we describe new features of EV production, revealing its capacity to shed two different enriched EV populations: large (LEV) and small extracellular vesicles (SEV) and identified relevant adhesion functions associated with the larger population. Proteomic analysis revealed differences in proteins relevant for virulence and host-pathogen interactions between the two EV subsets, such as cytoskeletal and anti-oxidative stress response proteins in LEVS. We assessed the effect of two recently identified inhibitors of EV release in mammalian cells, namely peptidylarginine deiminase (PAD) inhibitor and cannabidiol (CBD), on EV release from . The compounds were both able to effectively reduce EV shedding, the PAD-inhibitor specifically affecting the release of LEVs and reducing parasite attachment to host cells . Our results suggest that LEVs and SEVs have a different role in host-pathogen interaction, and that treatment with EV-inhibitors may be a novel treatment strategy for recurrent giardiasis. [Abstract copyright: Copyright © 2020 Gavinho, Sabatke, Feijoli, Rossi, da Silva, Evans-Osses, Palmisano, Lange and Ramirez.

Acute Hypoxia Alters Extracellular Vesicle Signatures and the Brain Citrullinome of Naked Mole-Rats (<i>Heterocephalus glaber</i>)

Peptidylarginine deiminases (PADs) and extracellular vesicles (EVs) may be indicative biomarkers of physiological and pathological status and adaptive responses, including to diseases and disorders of the central nervous system (CNS) and related to hypoxia. While these markers have been studied in hypoxia-intolerant mammals, in vivo investigations in hypoxia-tolerant species are lacking. Naked mole-rats (NMR) are among the most hypoxia-tolerant mammals and are thus a good model organism for understanding natural and beneficial adaptations to hypoxia. Thus, we aimed to reveal CNS related roles for PADs in hypoxia tolerance and identify whether circulating EV signatures may reveal a fingerprint for adaptive whole-body hypoxia responses in this species. We found that following in vivo acute hypoxia, NMR: (1) plasma-EVs were remodelled, (2) whole proteome EV cargo contained more protein hits (including citrullinated proteins) and a higher number of associated KEGG pathways relating to the total proteome of plasma-EVs Also, (3) brains had a trend for elevation in PAD1, PAD3 and PAD6 protein expression, while PAD2 and PAD4 were reduced, while (4) the brain citrullinome had a considerable increase in deiminated protein hits with hypoxia (1222 vs. 852 hits in normoxia). Our findings indicate that circulating EV signatures are modified and proteomic content is reduced in hypoxic conditions in naked mole-rats, including the circulating EV citrullinome, while the brain citrullinome is elevated and modulated in response to hypoxia. This was further reflected in elevation of some PADs in the brain tissue following acute hypoxia treatment. These findings indicate a possible selective role for PAD-isozymes in hypoxia response and tolerance

microRNA 1307 Is a Potential Target for SARS-CoV-2 Infection: An <i>in Vitro</i> Model

microRNAs (miRs) are proposed as critical molecular targets in SARS-CoV-2 infection. Our recent in silico studies identified seven SARS-CoV-2 specific miR-like sequences, which are highly conserved with humans, including miR-1307-3p, with critical roles in COVID-19. In this current study, Vero cells were infected with SARS-CoV-2, and miR expression profiles were thereafter confirmed by qRT-PCR. miR-1307-3p was the most highly expressed miR in the infected cells; we, therefore, transiently inhibited its expression in both infected and uninfected cells. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) cell proliferation assay assessed cell viability following SARS-CoV-2 infection, identifying that miR-1307 expression is inversely correlated with cell viability. Lastly, changes in miR-1307-dependent pathways were analyzed through a detailed miRNOME and associated in silico analysis. In addition to our previously identified miRs, including miR-1307-3p, the upregulation of miR-193a-5p, miR-5100, and miR-23a-5p and downregulation of miR-130b-5p, miR34a-5p, miR-505-3p, miR181a-2-3p, miR-1271-5p, miR-598-3p, miR-34c-3p, and miR-129-5p were also established in Vero cells related to general lung disease-related genes following SARS-CoV-2 infection. Targeted anti-miR-1307-3p treatment rescued cell viability in infection when compared to SARS CoV-2 mediated cell cytotoxicity only. We furthermore identified by in silico analysis that miR-1307-3p is conserved in all SARS-CoV-2 sequences/strains, except in the BA.2 variant, possibly contributing to the lower disease severity of this variant, which warrants further investigation. Small RNA seq analysis was next used to evaluate alterations in the miRNOME, following miR-1307-3p manipulation, identifying critical pathobiological pathways linked to SARS-CoV-2 infection-mediated upregulation of this miR. On the basis of our findings, miRNAs like miR-1307-3p play a critical role in SARS-CoV-2 infection, including via effects on disease progression and severity

The Extracellular Vesicle Citrullinome and Signature in a Piglet Model of Neonatal Seizures

Neonatal seizures are commonly associated with acute perinatal brain injury, while understanding regarding the downstream molecular pathways related to seizures remains unclear. Furthermore, effective treatment and reliable biomarkers are still lacking. Post-translational modifications can contribute to changes in protein function, and post-translational citrullination, which is caused by modification of arginine to citrulline via the calcium-mediated activation of the peptidylarginine deiminase (PAD) enzyme family, is being increasingly linked to neurological injury. Extracellular vesicles (EVs) are lipid-bilayer structures released from cells; they can be isolated from most body fluids and act as potential liquid biomarkers for disease conditions and response to treatment. As EVs carry a range of genetic and protein cargo that can be characteristic of pathological processes, the current study assessed modified citrullinated protein cargo in EVs isolated from plasma and CSF in a piglet neonatal seizure model, also following phenobarbitone treatment. Our findings provide novel insights into roles for PAD-mediated changes on EV signatures in neonatal seizures and highlight the potential of plasma- and CSF-EVs to monitor responses to treatment

microRNA 1307 Is a Potential Target for SARS-CoV-2 Infection: An in Vitro Model

microRNAs (miRs) are proposed as critical molecular targets in SARS-CoV-2 infection. Our recent in silico studies identified seven SARS-CoV-2 specific miR-like sequences, which are highly conserved with humans, including miR-1307-3p, with critical roles in COVID-19. In this current study, Vero cells were infected with SARS-CoV-2, and miR expression profiles were thereafter confirmed by qRT-PCR. miR-1307-3p was the most highly expressed miR in the infected cells; we, therefore, transiently inhibited its expression in both infected and uninfected cells. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) cell proliferation assay assessed cell viability following SARS-CoV-2 infection, identifying that miR-1307 expression is inversely correlated with cell viability. Lastly, changes in miR-1307-dependent pathways were analyzed through a detailed miRNOME and associated in silico analysis. In addition to our previously identified miRs, including miR-1307-3p, the upregulation of miR-193a-5p, miR-5100, and miR-23a-5p and downregulation of miR-130b-5p, miR34a-5p, miR-505-3p, miR181a-2-3p, miR-1271-5p, miR-598-3p, miR-34c-3p, and miR-129-5p were also established in Vero cells related to general lung disease-related genes following SARS-CoV-2 infection. Targeted anti-miR-1307-3p treatment rescued cell viability in infection when compared to SARS CoV-2 mediated cell cytotoxicity only. We furthermore identified by in silico analysis that miR-1307-3p is conserved in all SARS-CoV-2 sequences/strains, except in the BA.2 variant, possibly contributing to the lower disease severity of this variant, which warrants further investigation. Small RNA seq analysis was next used to evaluate alterations in the miRNOME, following miR-1307-3p manipulation, identifying critical pathobiological pathways linked to SARS-CoV-2 infection-mediated upregulation of this miR. On the basis of our findings, miRNAs like miR-1307-3p play a critical role in SARS-CoV-2 infection, including via effects on disease progression and severity

The Extracellular Vesicle Citrullinome and Signature in a Piglet Model of Neonatal Seizures

Neonatal seizures are commonly associated with acute perinatal brain injury, while understanding regarding the downstream molecular pathways related to seizures remains unclear. Furthermore, effective treatment and reliable biomarkers are still lacking. Post-translational modifications can contribute to changes in protein function, and post-translational citrullination, which is caused by modification of arginine to citrulline via the calcium-mediated activation of the peptidylarginine deiminase (PAD) enzyme family, is being increasingly linked to neurological injury. Extracellular vesicles (EVs) are lipid-bilayer structures released from cells; they can be isolated from most body fluids and act as potential liquid biomarkers for disease conditions and response to treatment. As EVs carry a range of genetic and protein cargo that can be characteristic of pathological processes, the current study assessed modified citrullinated protein cargo in EVs isolated from plasma and CSF in a piglet neonatal seizure model, also following phenobarbitone treatment. Our findings provide novel insights into roles for PAD-mediated changes on EV signatures in neonatal seizures and highlight the potential of plasma- and CSF-EVs to monitor responses to treatment