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FASEB Journal : Official Publication of... Jul 2024As we enter a new era of mRNA-based therapeutics, evidence on genetic or environmental factors that might predispose to unknown off-target side effects, gains in...
As we enter a new era of mRNA-based therapeutics, evidence on genetic or environmental factors that might predispose to unknown off-target side effects, gains in importance. Among these factors, exercise appears likely to have influenced otherwise cryptic cases of early-onset postvaccination myocarditis. And the existence of a distinct late-onset myocarditis is now being recognized. Here, three case-history reports suggest crypticity (the author's own case), unless provoked by a preexisting cardiac morbidity (one case), or by immune checkpoint blockade to enhance anticancer autoimmunity (several cases). These reports are supported by noninvasive fluorodeoxyglucose-based cardiac scan comparisons of multiple vaccinated and unvaccinated subjects. In pre-pandemic decades, applications for funds by the leading innovator in mRNA-based therapeutics seldom gained peer-review approval. Thus, at the start of the pandemic, the meager data on such side effects could justify only emergency approval. We must do better.
PubMed: 38959046
DOI: 10.1096/fj.202302692RR -
Proceedings of the National Academy of... Jul 2024Mammalian transglutaminases, a family of Ca-dependent proteins, are implicated in a variety of diseases. For example, celiac disease (CeD) is an autoimmune disorder...
Mammalian transglutaminases, a family of Ca-dependent proteins, are implicated in a variety of diseases. For example, celiac disease (CeD) is an autoimmune disorder whose pathogenesis requires transglutaminase 2 (TG2) to deamidate select glutamine residues in diet-derived gluten peptides. Deamidation involves the formation of transient γ-glutamyl thioester intermediates. Recent studies have revealed that in addition to the deamidated gluten peptides themselves, their corresponding thioester intermediates are also pathogenically relevant. A mechanistic understanding of this relevance is hindered by the absence of any structure of Ca-bound TG2. We report the X-ray crystallographic structure of human TG2 bound to an inhibitory gluten peptidomimetic and two Ca ions in sites previously designated as S1 and S3. Together with additional structure-guided experiments, this structure provides a mechanistic explanation for how S1 regulates formation of an inhibitory disulfide bond in TG2, while also establishing that S3 is essential for γ-glutamyl thioester formation. Furthermore, our crystallographic findings and associated analyses have revealed that i) two interacting residues, H305 and E363, play a critical role in resolving the thioester intermediate into an isopeptide bond (transamidation) but not in thioester hydrolysis (deamidation); and ii) residues N333 and K176 stabilize preferred TG2 substrates and inhibitors via hydrogen bonding to nonreactive backbone atoms. Overall, the intermediate-state conformer of TG2 reported here represents a superior model to previously characterized conformers for both transition states of the TG2-catalyzed reaction.
Topics: Transglutaminases; Protein Glutamine gamma Glutamyltransferase 2; Humans; Calcium; GTP-Binding Proteins; Crystallography, X-Ray; Glutens; Models, Molecular; Protein Conformation; Celiac Disease; Protein Binding
PubMed: 38959038
DOI: 10.1073/pnas.2407066121 -
Head and Neck Pathology Jul 2024There are a number of diagnostic criteria that can be used to support a diagnosis of Sjögren's syndrome (SS), a chronic autoimmune condition often characterised by...
PURPOSE
There are a number of diagnostic criteria that can be used to support a diagnosis of Sjögren's syndrome (SS), a chronic autoimmune condition often characterised by xerostomia and xerophthalmia. Of the available investigations, the most invasive is the labial gland biopsy (LGB) for histopathology, which is associated with a risk of long-term altered sensation to the lip. A positive histological diagnosis is currently considered to be one of the most objective criteria, however there is debate about the interobserver agreement between pathologists, as well as the sensitivity and specificity of this test. We aim to determine if the diagnostic value of the LGB is significant enough to warrant the surgical procedure and its associated risks.
METHODS
This study involved assessing the degree of agreement between members of a pathology team for a cohort of 50 LGBs taken for the purpose of confirming or excluding SS. The Tarpley system was used, which involves the allocation of a 'focus score'. Additionally, the histological diagnoses were compared to the relevant serological findings where available.
RESULTS
All cases within the cohort had adequate tissue for assessment. 84% agreement (Cohen's Kappa = 0.585) was seen between the current team's consensus and the original reporting pathologist on whether the appearance was supportive of SS. However, only 58% agreement was seen for focus scores (Weighted Kappa = 0.496). The agreement between the serology result and whether the histology was supportive of SS was 79% (Cohen's Kappa = 0.493).
CONCLUSION
The findings raise the possibility that undue emphasis is placed on the value of a histological SS diagnosis. The current system for assessing and grading these biopsies is ambiguous in nature, with a low threshold considered indicative of SS. Due to the risk of complications associated with a LGB, alternative minimally invasive investigations should always be considered. The histological findings in isolation, particularly when a low focus score is seen, may not be predictive of a diagnosis of SS.
Topics: Humans; Sjogren's Syndrome; Biopsy; Salivary Glands, Minor; Female; Middle Aged; Aged; Adult; Male; Sensitivity and Specificity
PubMed: 38958850
DOI: 10.1007/s12105-024-01662-1 -
Purinergic Signalling Jul 2024Ectonucleotidase inhibitors are a family of pharmacological drugs that, by selectively targeting ectonucleotidases, are essential in altering purinergic signaling... (Review)
Review
Ectonucleotidase inhibitors are a family of pharmacological drugs that, by selectively targeting ectonucleotidases, are essential in altering purinergic signaling pathways. The hydrolysis of extracellular nucleotides and nucleosides is carried out by these enzymes, which include ectonucleoside triphosphate diphosphohydrolases (NTPDases) and ecto-5'-nucleotidase (CD73). Ectonucleotidase inhibitors can prevent the conversion of ATP and ADP into adenosine by blocking these enzymes and reduce extracellular adenosine. These molecules are essential for purinergic signaling, which is associated with a variability of physiological and pathological processes. By modifying extracellular nucleotide metabolism and improving purinergic signaling regulation, ectonucleotide pyrophosphatase/phosphodiesterase (ENPP) inhibitors have the potential to improve cancer treatment, inflammatory management, and immune response modulation. Purinergic signaling is affected by CD73 inhibitors because they prevent AMP from being converted to adenosine. These inhibitors are useful in cancer therapy and immunotherapy because they may improve chemotherapy effectiveness and alter immune responses. Purinergic signaling is controlled by NTPDase inhibitors, which specifically target enzymes involved in extracellular nucleotide breakdown. These inhibitors show promise in reducing immunological responses, thrombosis, and inflammation, perhaps assisting in the treatment of cardiovascular and autoimmune illnesses. Alkaline phosphatase (ALP) inhibitors alter the function of enzymes involved in dephosphorylation reactions, which has an impact on a variety of biological processes. By altering the body's phosphate levels, these inhibitors may be used to treat diseases including hyperphosphatemia and certain bone problems. This article provides a guide for researchers and clinicians looking to leverage the remedial capability of ectonucleotidase inhibitors in a variety of illness scenarios by illuminating their processes, advantages, and difficulties.
PubMed: 38958821
DOI: 10.1007/s11302-024-10031-0 -
Archives of Dermatological Research Jul 2024Several auto-immune diseases have been linked to vitamin D deficiency as a contributing environmental factor. Its pleiotropic effects on the immune system, especially...
Several auto-immune diseases have been linked to vitamin D deficiency as a contributing environmental factor. Its pleiotropic effects on the immune system, especially its essential role in maintaining immune tolerance, make the vitamin D pathway of great interest. In this study, we focused on Pemphigus foliaceous (PF) in Tunisian population. we aimed to quantify the Serum 25[OH]D levels using chemiluminescence assay and to analyze the differential expression of the VDR, CYP27B1 and CYP24A1 genes in the circulating blood cells and lesional skin tissue of PF patients using Q-PCR. A genetic explanation was then sought to explore any direct relationship between tag polymorphisms and the inherited features of PF. Results confirmed a vitamin D hypovitaminosis in Tunisian PF patients. Interestingly, a differential gene expression correlated to the disease stratification was noted. Indeed, at the systemic level, an upregulation of VDR and CYP27B1 genes was observed in healthy controls compared to PF patients. Notably, in lesional skin tissue, the clinical and serological remission phase was correlated with high transcriptional levels of the VDR gene and conversely a drop in expression of the CYP24A1 gene. Genetic analysis indicated the involvement of the most appealing polymorphisms, rs2228570 and poly (A) microsatellite, in PF etiopathogenesis. Indeed, CAC13 haplotype was associated with a higher risk of PF development. Our findings suggest that alterations in the vitamin D-VDR pathway may influence PF physiopathology, making this pathway a potential target for pharmacological modulation, especially for cortico-resistant PF patients.
Topics: Humans; Pemphigus; Receptors, Calcitriol; Vitamin D3 24-Hydroxylase; 25-Hydroxyvitamin D3 1-alpha-Hydroxylase; Vitamin D; Female; Male; Middle Aged; Adult; Vitamin D Deficiency; Tunisia; Aged; Polymorphism, Single Nucleotide; Skin; Genetic Predisposition to Disease; Case-Control Studies
PubMed: 38958777
DOI: 10.1007/s00403-024-03192-w -
Neoplasma Jun 2024The increasing occurrence of multiple primary cancers (MPC) is a long-term trend, but the prevalence of MPC in patients with hepatocellular carcinoma (HCC) and its...
The increasing occurrence of multiple primary cancers (MPC) is a long-term trend, but the prevalence of MPC in patients with hepatocellular carcinoma (HCC) and its impact on overall survival (OS) remains unknown. We retrospectively analyzed 497 patients with HCC treated at two tertiary centers. The cohort was divided into two subgroups - liver transplant (LT, 324 patients) and non-liver transplant (non-LT, 173 patients). We analyzed MPC occurrence, its impact on survival, and identified variables predicting unfavorable outcomes. The MPC were detected in 88 patients (18%). The most common MPC were prostate (17%), skin (15.9%), kidney (12.5%), and lung (10.2%). The median OS of the whole cohort and the LT and non-LT subgroups were 70, 116, and 17 months, respectively (p<0.0001). The median OS in patients with HCC only and HCC with another cancer was 77 (95% CI, 67-96) and 50 months (95% CI, 37-62), respectively (p=0.25). The OS of LT patients was significantly better than that of those in whom LT had been contraindicated owing to concomitant MPC (116 vs. 35 months, p<0.0009). Autoimmune etiology, non-alcoholic steatohepatitis (NASH), HCC as the first diagnosed malignancy, and male sex were identified as factors significantly influencing the patients' outcomes (HR 0.43, 3.2326, 0.70, and 1.43, respectively). The MPC frequency was 18%. The impact of MPC on OS was not significant, except for individuals contraindicated for LT because of MPC. A better prognosis is associated with the autoimmune etiology of cirrhosis, and when HCC is diagnosed as the first malignancy. Male sex and NASH worsened the outcomes.
Topics: Humans; Carcinoma, Hepatocellular; Liver Neoplasms; Male; Female; Neoplasms, Multiple Primary; Retrospective Studies; Middle Aged; Liver Transplantation; Aged; Prognosis; Adult
PubMed: 38958713
DOI: 10.4149/neo_2024_231217N649 -
Clinical and Experimental Medicine Jul 2024This comprehensive exploration delves into the pivotal role of microRNAs (miRNAs) within the intricate tapestry of cellular regulation. As potent orchestrators of gene... (Review)
Review
This comprehensive exploration delves into the pivotal role of microRNAs (miRNAs) within the intricate tapestry of cellular regulation. As potent orchestrators of gene expression, miRNAs exhibit diverse functions in cellular processes, extending their influence from the nucleus to the cytoplasm. The complex journey of miRNA biogenesis, involving transcription, processing, and integration into the RNA-induced silencing complex, showcases their versatility. In the cytoplasm, mature miRNAs finely tune cellular functions by modulating target mRNA expression, while their reach extends into the nucleus, influencing transcriptional regulation and epigenetic modifications. Dysregulation of miRNAs becomes apparent in various pathologies, such as cancer, autoimmune diseases, and inflammatory conditions. The adaptability of miRNAs to environmental signals, interactions with transcription factors, and involvement in intricate regulatory networks underscore their significance. DNA methylation and histone modifications adds depth to understanding the dynamic regulation of miRNAs. Mechanisms like competition with RNA-binding proteins, sponging, and the control of miRNA levels through degradation and editing contribute to this complex regulation process. In this review, we mainly focus on how dysregulation of miRNA expression can be related with skin-related autoimmune and autoinflammatory diseases, arthritis, cardiovascular diseases, inflammatory bowel disease, autoimmune and autoinflammatory diseases, and neurodegenerative disorders. We also emphasize the multifaceted roles of miRNAs, urging continued research to unravel their complexities. The mechanisms governing miRNA functions promise advancements in therapeutic interventions and enhanced insights into cellular dynamics in health and disease.
Topics: Humans; MicroRNAs; Inflammation; Gene Expression Regulation; Autoimmune Diseases; Epigenesis, Genetic; Neurodegenerative Diseases
PubMed: 38958690
DOI: 10.1007/s10238-024-01334-y -
Journal of Cellular Physiology Jul 2024Autophagy is a lysosome-mediated self-degradation process of central importance for cellular quality control. It also provides macromolecule building blocks and... (Review)
Review
Autophagy is a lysosome-mediated self-degradation process of central importance for cellular quality control. It also provides macromolecule building blocks and substrates for energy metabolism during nutrient or energy deficiency, which are the main stimuli for autophagy induction. However, like most biological processes, autophagy itself requires ATP, and there is an energy threshold for its initiation and execution. We here present the first comprehensive review of this often-overlooked aspect of autophagy research. The studies in which ATP deficiency suppressed autophagy in vitro and in vivo were classified according to the energy pathway involved (oxidative phosphorylation or glycolysis). A mechanistic insight was provided by pinpointing the critical ATP-consuming autophagic events, including transcription/translation/interaction of autophagy-related molecules, autophagosome formation/elongation, autophagosome fusion with the lysosome, and lysosome acidification. The significance of energy-dependent fine-tuning of autophagic response for preserving the cell homeostasis, and potential implications for the therapy of cancer, autoimmunity, metabolic disorders, and neurodegeneration are discussed.
PubMed: 38958520
DOI: 10.1002/jcp.31366 -
The Journal of Physical Chemistry. B Jul 2024The herpesvirus entry mediator (HVEM) and its ligand LIGHT play crucial roles in immune system regulation, including T-cell proliferation, B-cell differentiation, and...
The herpesvirus entry mediator (HVEM) and its ligand LIGHT play crucial roles in immune system regulation, including T-cell proliferation, B-cell differentiation, and immunoglobulin secretion. However, excessive T-cell activation can lead to chronic inflammation and autoimmune diseases. Thus, inhibiting the HVEM-LIGHT interaction emerges as a promising therapeutic strategy for these conditions and in preventing adverse reactions in organ transplantation. This study focused on designing peptide inhibitors, targeting the HVEM-LIGHT interaction, using molecular dynamics (MD) simulations of 65 peptides derived from HVEM. These peptides varied in length and disulfide-bond configurations, crucial for their interaction with the LIGHT trimer. By simulating 31 HVEM domain variants, including the full-length protein, we assessed conformational changes upon LIGHT binding to understand the influence of HVEM segments and disulfide bonds on the binding mechanism. Employing multitrajectory microsecond-scale, all-atom MD simulations and molecular mechanics with generalized Born and surface area (MM-GBSA) binding energy estimation, we identified promising CRD2 domain variants with high LIGHT affinity. Notably, point mutations in these variants led to a peptide with a single disulfide bond (C58-C73) and a K54E substitution, exhibiting the highest binding affinity. The importance of the CRD2 domain and Cys58-Cys73 disulfide bond for interrupting HVEM-LIGHT interaction was further supported by analyzing truncated CRD2 variants, demonstrating similar binding strengths and mechanisms. Further investigations into the binding mechanism utilized steered MD simulations at various pulling speeds and umbrella sampling to estimate the energy profile of HVEM-based inhibitors with LIGHT. These comprehensive analyses revealed key interactions and different binding mechanisms, highlighting the increased binding affinity of selected peptide variants. Experimental circular dichroism techniques confirmed the structural properties of these variants. This study not only advances our understanding of the molecular basis of HVEM-LIGHT interactions but also provides a foundation for developing novel therapeutic strategies for immune-related disorders. Furthermore, it sets a gold standard for peptide inhibitor design in drug development due to its systematic approach.
PubMed: 38958133
DOI: 10.1021/acs.jpcb.4c02255 -
Arteriosclerosis, Thrombosis, and... Jul 2024Tight control of cytoplasmic Ca in endothelial cells is essential for the regulation of endothelial barrier function. Here, we investigated the role of Cavβ3, a subunit...
BACKGROUND
Tight control of cytoplasmic Ca in endothelial cells is essential for the regulation of endothelial barrier function. Here, we investigated the role of Cavβ3, a subunit of voltage-gated Ca (Cav) channels, in modulating Ca signaling in brain microvascular endothelial cells (BMECs) and how this contributes to the integrity of the blood-brain barrier.
METHODS
We investigated the function of Cavβ3 in BMECs by Ca imaging and Western blot, examined the endothelial barrier function in vitro and the integrity of the blood-brain barrier in vivo, and evaluated disease course after induction of experimental autoimmune encephalomyelitis in mice using Cavβ3 (Cav β3-deficient) mice as controls.
RESULTS
We identified Cavβ3 protein in BMECs, but electrophysiological recordings did not reveal significant Cav channel activity. In vivo, blood-brain barrier integrity was reduced in the absence of Cavβ3. After induction of experimental autoimmune encephalomyelitis, Cavβ3 mice showed earlier disease onset with exacerbated clinical disability and increased T-cell infiltration. In vitro, the transendothelial resistance of Cavβ3 BMEC monolayers was lower than that of wild-type BMEC monolayers, and the organization of the junctional protein ZO-1 (zona occludens-1) was impaired. Thrombin stimulates inositol 1,4,5-trisphosphate-dependent Ca release, which facilitates cell contraction and enhances endothelial barrier permeability via Ca-dependent phosphorylation of MLC (myosin light chain). These effects were more pronounced in Cavβ3 than in wild-type BMECs, whereas the differences were abolished in the presence of the MLCK (MLC kinase) inhibitor ML-7. Expression of cDNA in Cavβ3 BMECs restored the wild-type phenotype. Coimmunoprecipitation and mass spectrometry demonstrated the association of Cavβ3 with inositol 1,4,5-trisphosphate receptor proteins.
CONCLUSIONS
Independent of its function as a subunit of Cav channels, Cavβ3 interacts with the inositol 1,4,5-trisphosphate receptor and is involved in the tight control of cytoplasmic Ca and Ca-dependent MLC phosphorylation in BMECs, and this role of Cavβ3 in BMECs contributes to blood-brain barrier integrity and attenuates the severity of experimental autoimmune encephalomyelitis disease.
PubMed: 38957986
DOI: 10.1161/ATVBAHA.124.321141