Cytokine Targeting by miRNAs in Autoimmune Diseases

Comparison of different protocols of RNA preparation from circulating blood for RNA sequencing

OBJECTIVE

Circulating miRNAs have been extensively used in studies of neurological diseases. Thus, methods to extract high quantity total RNA for RNA sequencing (RNA-seq) and real-time quantitative polymerase chain reaction (RT-qPCR) are needed. However, the extraction of sufficient high-quality nucleic acids from circulating blood is difficult. Differences in eccentricity, cryopreservation conditions and extraction methods may affect RNA quantity and quality. Here, we systematically compared six blood-RNA extraction protocols (protocols 1, 2, 3, 4, 5, and 6; see the methods section for details).

RESULTS

Protocol 1 yielded the highest quality and quantity of RNA; protocol 2, protocol 5 and protocol 6 produced RNA of intermediate quality; and protocols 3 and 4 yielded the lowest quality RNA. The RNA integrity number (RIN) for isolated RNA was > 9.0 when protocol 1 or protocol 2 was used, > 8.0 when protocol 5 was used, and > 7.0 when protocol 6 was used; lower values were obtained when protocol 3 or 4 was used. The RNA extracted from circulating blood using protocol 1 was most intact and suitable for RT-qPCR and RNA-seq.

CONCLUSIONS

The quality of RNA extracted from circulating blood is affected by high-speed centrifugation and cryopreservation. Adding an RNA stabilizer during the cryopreservation of circulating blood significantly improved RNA quality and quantity. The quality of extracted RNA from circulating blood is improved when using TRIzol relative to that attained with a commercial kit.

Ultra-Low Dose Cytokines in Rheumatoid Arthritis, Three Birds with One Stone as the Rationale of the 2LARTH® Micro-Immunotherapy Treatment

Tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) are two cytokines involved in the perpetuation of the chronic inflammation state characterizing rheumatoid arthritis (RA). Significant advances in the treatment of this pathology have been made over the past ten years, partially through the development of anti-TNF and anti-IL-1 therapies. However, major side effects still persist and new alternative therapies should be considered. The formulation of the micro-immunotherapy medicine (MIM) 2LARTH^® uses ultra-low doses (ULD) of TNF-α, IL-1β, and IL-2, in association with other immune factors, to gently restore the body’s homeostasis. The first part of this review aims at delineating the pivotal roles played by IL-1β and TNF-α in RA physiopathology, leading to the development of anti-TNF and anti-IL-1 therapeutic agents. In a second part, an emphasis will be made on explaining the rationale of using multiple therapeutic targets, including both IL-1β and TNF-α in 2LARTH^® medicine. Particular attention will be paid to the ULD of those two main pro-inflammatory factors in order to counteract their overexpression through the lens of their molecular implication in RA pathogenesis.

Integrated analysis on mRNA microarray and microRNA microarray to screen immune-related biomarkers and pathways in myelodysplastic syndrome

BACKGROUND

Myelodysplastic syndrome (MDS) is a haematopoietic malignancy that is characterized by a heterogeneous clinical course and dysplastic maturation of blood lineages. Immune dysregulation has gained attention as one of the fundamental mechanisms responsible for the development of MDS. This study aimed to screen immune-related biomarkers and pathways in MDS.

METHODS

Differentially expressed mRNAs (DE-mRNAs) and differentially expressed microRNAs (DE-miRNAs) in different subtypes of MDS were sourced from the Gene Expression Omnibus (GEO) database. DE-mRNAs were intersected with immune-related gene sets to collect immune-related mRNAs, which were put into the Search Tool for the Retrieval of Interacting Genes (STRING) to construct protein-protein interaction (PPI) networks. Target mRNAs of DE-miRNAs were predicted using the miRDB database and intersected with screened immune-related mRNAs to construct miRNA-mRNA interaction networks. Topological analysis of constructed networks was applied to screen key molecules, which were assessed in independent datasets and previous literature. Enrichment analysis was applied to screen dysregulated pathways in MDS.

RESULTS

Screened key mRNAs were mainly from the Toll-like receptor (TLR) family, including TLR2, TLR4, TLR7, and from the chemokine family, including C-X-C motif chemokine ligand 10 (CXCL10) and CC chemokine ligand 4 (CCL4). Cytokine-cytokine receptor interactions were among the major pathways in the enrichment analysis results. Hsa-miR-30b, hsa-miR-30e and hsa-miR-221 were validated as key miRNAs and modulate cytokine-cytokine receptor interactions by targeting immune-related mRNAs.

CONCLUSION

Dysregulated cytokines reflect the immunization status in MDS. Immune-related miRNA-mRNA interactions not only provide a perspective to our understanding of immunologic derangement in the pathogenesis of MDS but also provide new therapeutic opportunities.

The role of miRNAs in the regulation of autophagy in autoimmune diseases

Autoimmune diseases (AD), which are classified as chronic injuries, are caused by a specific auto-reactive reaction. The etiology of most ADs is not well understood. Meanwhile, Autophagy is a protective response defining as a catabolic method by lysosomes tending to maintain homeostasis acts by recycling and discrediting cell compartments. Autophagy plays a crucial role in controlling immune homeostasis by eliminating intracellular pathogens and presenting antigens to immune cognition. MicroRNAs are commonly known as endogenous non-coding small RNAs, which span 18-25 nt and take part in the gene expression at the post-transcriptional level regulation. miRNAs play important roles in different processes like, cell differentiation, duplicating, and apoptosis. Moreover, miRNAs are the critical molecules for the regular function of the immune system by modulating immune tolerance mechanisms and autoimmunity. Recent findings support the role of dysregulated miRNAs in the pathogenesis of ADs and in the regulation of autophagy. In this review, we will focus on the role of the miRNAs in the regulation of autophagy and then will explain the role of dysregulated miRNAs in the initiation of the ADs by modulating autophagy.

Cannabinoid-induced changes in the immune system: The role of microRNAs

Naturally occurring cannabinoids have been used by humans for their medicinal benefits for over several millennia. While the use of cannabinoids has been strictly regulated in the past century, easing of state regulations has been associated with an increase in use of cannabinoids in the United States. The potential therapeutic applications of cannabinoids have been explored and the anti-inflammatory effect of cannabis-derived cannabinoids has been well-documented. The pharmacological effects of cannabinoids are governed by the modulation of cannabinoid receptors, CB₁ and CB₂, expressed in the central and peripheral tissues. Moreover, growing scientific evidence suggests that the cannabinoid-mediated changes in the immune system involves change in expression of microRNAs (miRNAs). MiRNAs are short non-coding, single-stranded RNA which have the ability to affect post-translational regulation of gene expression. Studies over the past decade have investigated the changes in expression of miRNAs following treatment of various components of the immune system with different chemical modulators of the cannabinoid receptors. Such studies have highlighted the key role played by various miRNAs in driving the observed immunomodulatory effects of cannabinoids. The aim of this review article, therefore, is to summarize the role of miRNAs behind the observed effects of cannabinoids on the overall immune system, rather than focusing on a single disease state.

Circulating microRNA profile unveils mechanisms of action of acitretin for psoriasis vulgaris

Psoriasis vulgaris is a common chronic and recurrent inflammatory skin disease. In clinical practice, acitretin is the first-line treatment drug for psoriasis vulgaris. MicroRNAs (miRNAs) play a vital role in the initiation and development of psoriasis vulgaris. However few studies focused on the mechanisms of acitretin in the treatment of psoriasis vulgaris from the perspective of miRNAs. Here, the expression profiles of circulating miRNAs in the plasma of 12 patients with psoriasis vulgaris before and after acitretin treatment were sequenced. Three miRNAs (miR-146a-5p, miR-122-5p and miR-21-5p) were identified using expression pattern analysis, and the levels were significantly decreased after acitretin treatment (P< 0.001). Receiver operating characteristic (ROC) analyses indicated that the three miRNAs have the potential to be utilized as molecular markers to evaluate the therapeutic effect of acitretin, and the values of the area under the curve (AUC) were 0.825, 0.831, and 0.796, respectively. In addition, we predicted target genes of the three miRNAs and performed signaling pathway enrichment analyses. The results demonstrated that the target genes were mainly involved in the MAPK, JAK-STAT, and NF-κB signaling pathways, which were further validated through in vitro experiments. In conclusion, acitretin can suppress miRNA-mediated MAPK, JAK-STAT, and NF-κB signaling pathways by decreasing miRNAs expression, thereby inhibiting the proliferation and inflammatory response of keratinocytes.

TLR7 endogenous ligands remodel glycolytic macrophages and trigger skin-to-joint crosstalk in psoriatic arthritis

Thirty percent of psoriasis patients develop psoriatic arthritis (PsA), nevertheless the mechanism remains unknown. Endogenous GU-rich miRNAs activate endosomal TLR7 that plays a critical role in autoimmune diseases. We found that endogenous TLR7 ligands, miR-29 and miR-Let7b, were markedly increased in PsA compared to osteoarthritis (OA) synovial fluid (SF)s. We showed that intradermal (i.d.) miR-Let7b injection promoted skin inflammation, which was characterized by amplified Th1 cells, CD68+ M1 macrophages, and transcriptional upregulation of glycolytic mediators, GLUT1, C-MYC, and HIF1α. Expansion of skin Th1 cells driven by miR-Let7b was also linked to elevated M1-associated IRFs. Interestingly, i.d. miR-Let7b administration exacerbated suboptimal joint inflammation along with metabolic reconfiguration of the PsA-like preclinical model. Moreover, TLR7 agonist, R837, potentiated metabolic reprogramming and expression of IL-1β, IL-6, and IL-12 in murine macrophages, enabling myeloid-to-T-cell crosstalk. Consistently, treatment with glycolytic inhibitors, 2-DG and/or HIF1αi, reversed R837-induced metabolic remodeling and disrupted the TLR7-driven inflammatory phenotype in myeloid and lymphoid cells. Similar to miR-Let7b, R837 also differentiates progenitor cells into mature osteoclasts, primarily through RANKL induction. Taken together, this study indicates that TLR7-instigated metabolic rewiring of macrophages and their cross-regulation of T cells connects skin immunopathology to joint inflammation.

The microRNA let-7b-5p Is Negatively Associated with Inflammation and Disease Severity in Multiple Sclerosis

The identification of microRNAs in biological fluids for diagnosis and prognosis is receiving great attention in the field of multiple sclerosis (MS) research but it is still in its infancy. In the present study, we observed in a large sample of MS patients that let-7b-5p levels in the cerebrospinal fluid (CSF) were highly correlated with a number of microRNAs implicated in MS, as well as with a variety of inflammation-related protein factors, showing specific expression patterns coherent with let-7b-5p-mediated regulation. Additionally, we found that the CSF let-7b-5p levels were significantly reduced in patients with the progressive MS compared to patients with relapsing-remitting MS and were negatively correlated with characteristic hallmark processes of the two phases of the disease. Indeed, in the non-progressive phase, let-7b-5p inversely associated with both central and peripheral inflammation; whereas, in progressive MS, the CSF levels of let-7b-5p negatively correlated with clinical disability at disease onset and after a follow-up period. Overall, our results uncovered, by the means of a multidisciplinary approach and multiple statistical analyses, a new possible pleiotropic action of let-7b-5p in MS, with potential utility as a biomarker of MS course.

miRNA-Dependent CD4+ T Cell Differentiation in the Pathogenesis of Multiple Sclerosis

Multiple sclerosis (MS) is characterized by multifocal lesions, chronic inflammatory condition, and degenerative processes within the central nervous system (CNS) leading to demyelination. The most important cells involved in its pathogenesis are those which are CD4⁺, particularly proinflammatory Th1/Th17 and regulatory Treg. Signal cascades associated with CD4⁺ differentiation are regulated by microRNAs (miRNAs): short, single-stranded RNAs, responsible for negative regulation of gene expression at the posttranscriptional level. Several miRNAs have been consistently reported as showing dysregulated expression in MS, and their expression patterns may be elevated or decreased, depending on the function of specific miRNA in the immune system. Studies in MS patients indicate that, among others, miR-141, miR-200a, miR-155, miR-223, and miR-326 are upregulated, while miR-15b, miR-20b, miR-26a, and miR-30a are downregulated. Dysregulation of these miRNAs may contribute to the imbalance between pro- and anti-inflammatory processes, since their targets are associated with the regulation of Th1/Th17 and Treg cell differentiation. Highly expressed miRNAs can in turn suppress translation of key Th1/Th17 differentiation inhibitors. miRNA dysregulation may result from the impact of various factors at each stage of their biogenesis. Immature miRNA undergoes multistage transcriptional and posttranscriptional modifications; therefore, any protein involved in the processing of miRNAs can potentially lead to disturbances in their expression. Epigenetic modifications that have a direct impact on miRNA gene transcription may also play an important role.

Multi-omic analysis unveils biological pathways in peripheral immune system associated to minimal hepatic encephalopathy appearance in cirrhotic patients

Patients with liver cirrhosis may develop minimal hepatic encephalopathy (MHE) which affects their quality of life and life span. It has been proposed that a shift in peripheral inflammation triggers the appearance of MHE. However, the mechanisms involved in this immune system shift remain unknown. In this work we studied the broad molecular changes involved in the induction of MHE with the goal of identifying (1) altered genes and pathways in peripheral blood cells associated to the appearance of MHE, (2) serum metabolites and cytokines with modified levels in MHE patients and (3) MHE-regulated immune response processes related to changes in specific serum molecules. We adopted a multi-omic approach to profile the transcriptome, metabolome and a panel of cytokines of blood samples taken from cirrhotic patients with or without MHE. Transcriptomic analysis supports the hypothesis of alternations in the Th1/Th2 and Th17 lymphocytes cell populations as major drivers of MHE. Cluster analysis of serum molecules resulted in six groups of chemically similar compounds, suggesting that functional modules operate during the induction of MHE. Finally, the multi-omic integrative analysis suggested a relationship between cytokines CCL20, CX3CL1, CXCL13, IL-15, IL-22 and IL-6 with alteration in chemotaxis, as well as a link between long-chain unsaturated phospholipids and the increased fatty acid transport and prostaglandin production. We found altered immune pathways that may collectively contribute to the mild cognitive impairment phenotype in MHE. Our approach is able to combine extracellular and intracellular information, opening new insights to the understanding of the disease.

Endothelial to Mesenchymal Transition in Pulmonary Vascular Diseases

Lung diseases, such as pulmonary hypertension and pulmonary fibrosis, are life-threatening diseases and have common features of vascular remodeling. During progression, extracellular matrix protein deposition and dysregulation of proteolytic enzymes occurs, which results in vascular stiffness and dysfunction. Although vasodilators or anti-fibrotic therapy have been mainly used as therapy owing to these characteristics, their effectiveness does not meet expectations. Therefore, a better understanding of the etiology and new therapeutic approaches are needed. Endothelial cells (ECs) line the inner walls of blood vessels and maintain vascular homeostasis by protecting vascular cells from pathological stimuli. Chronic stimulation of ECs by various factors, including pro-inflammatory cytokines and hypoxia, leads to ECs undergoing an imbalance of endothelial homeostasis, which results in endothelial dysfunction and is closely associated with vascular diseases. Emerging studies suggest that endothelial to mesenchymal transition (EndMT) contributes to endothelial dysfunction and plays a key role in the pathogenesis of vascular diseases. EndMT is a process by which ECs lose their markers and show mesenchymal-like morphological changes, and gain mesenchymal cell markers. Despite the efforts to elucidate these molecular mechanisms, the role of EndMT in the pathogenesis of lung disease still requires further investigation. Here, we review the importance of EndMT in the pathogenesis of pulmonary vascular diseases and discuss various signaling pathways and mediators involved in the EndMT process. Furthermore, we will provide insight into the therapeutic potential of targeting EndMT.

Outer Membrane Vesicles Derived from Klebsiella pneumoniae Influence the miRNA Expression Profile in Human Bronchial Epithelial BEAS-2B Cells

Klebsiella pneumoniae is an opportunistic pathogen that causes nosocomial and community-acquired infections. The spread of resistant strains of K. pneumoniae represents a growing threat to human health, due to the exhaustion of effective treatments. K. pneumoniae releases outer membrane vesicles (OMVs). OMVs are a vehicle for the transport of virulence factors to host cells, causing cell injury. Previous studies have shown changes of gene expression in human bronchial epithelial cells after treatment with K. pneumoniae OMVs. These variations in gene expression could be regulated through microRNAs (miRNAs), which participate in several biological mechanisms. Thereafter, miRNA expression profiles in human bronchial epithelial cells were evaluated during infection with standard and clinical K. pneumoniae strains. Microarray analysis and RT-qPCR identified the dysregulation of miR-223, hsa-miR-21, hsa-miR-25 and hsa-let-7g miRNA sequences. Target gene prediction revealed the essential role of these miRNAs in the regulation of host immune responses involving NF-ĸB (miR-223), TLR4 (hsa-miR-21), cytokine (hsa-miR-25) and IL-6 (hsa-let-7g miRNA) signalling pathways. The current study provides the first large scale expression profile of miRNAs from lung cells and predicted gene targets, following exposure to K. pneumoniae OMVs. Our results suggest the importance of OMVs in the inflammatory response.

Nutraceutical Targeting of Inflammation-Modulating microRNAs in Severe Forms of COVID-19: A Novel Approach to Prevent the Cytokine Storm

The coronavirus disease 2019 (COVID-19) pandemic has become the number one health problem worldwide. As of August 2020, it has affected more than 18 million humans and caused over 700,000 deaths worldwide. COVID-19 is an infectious disease that can lead to severe acute respiratory syndrome. Under certain circumstances, the viral infection leads to excessive and uncontrolled inflammatory response, which is associated with the massive release of inflammatory cytokines in pulmonary alveolar structures. This phenomenon has been referred to as the “cytokine storm,” and it is closely linked to lung injury, acute respiratory syndrome and mortality. Unfortunately, there is currently no vaccine available to prevent the infection, and no effective treatment is available to reduce the mortality associated with the severe form of the disease. The cytokine storm associate with COVID-19 shows similarities with those observed in other pathologies such as sepsis, acute respiratory distress syndrome, acute lung injury and other viral infection including severe cases of influenza. However, the specific mechanisms that cause and modulate the cytokine storm in the different conditions remain to be determined. micro-RNAs are important regulators of gene expression, including key inflammatory cytokines involved in the massive recruitment of immune cells to the lungs such as IL1β, IL6, and TNFα. In recent years, it has been shown that nutraceutical agents can modulate the expression of miRs involved in the regulation of cytokines in various inflammatory diseases. Here we review the potential role of inflammatory-regulating-miRs in the cytokine storm associated with COVID-19, and propose that nutraceutical agents may represent a supportive therapeutic approach to modulate dysregulated miRs in this condition, providing benefits in severe respiratory diseases.

Differentially expressed circulating microRNAs associated with idiopathic recurrent pregnancy loss

Recurrent pregnancy loss (RPL) is a major pregnancy complication which reportedly affects 2-3% of all pregnancies. Currently, RPL lacks an effective therapy and a reliable diagnostic and prognostic biomarker. Circulating microRNAs were recently described as potential biomarkers of pregnancy-associated complications. The aim of this study was to determine microRNA expression patterns in the plasma of RPL patients as potential early biomarker of RPL. Study subjects comprised 20 women with early RPL (miscarriage at 8-12 weeks of gestation), and 20 age- and gestation-matched multiparous control women. Circulating microRNAs were extracted from maternal plasma, and the differential microRNA expression were determined using customized pathway-focused miRNA profiler kit. Of the 10 differentially-expressed microRNAs identified, Hsa-let-7e, Hsa-miR-221-3p, Hsa-miR-16, Hsa-miR-519d, Hsa-miR-184, Hsa-miR-410 were upregulated, while Hsa-miR-21, Hsa-miR-125, Hsa-let-7a, Hsa-let-7d were downregulated in RPL cases as compared to control women. Of these, 5 novel microRNAs were reported for the first time to be associated with RPL. These comprised Hsa-let-7e, Hsa-miR-519d, Hsa-miR-410 which were upregulated, and Hsa-let-7a, Hsa-let-7d which were downregulated in RPL. While its association with RPL was reported earlier, this study is also the first to report on the upregulation of Hsa-miR-184 in circulating fluids in association with RPL. The study provides for understanding circulating microRNAs expression pattern in RPL which may be involved in its pathogenesis and demonstrates their potential role as noninvasive diagnostic and prognostic biomarkers for RPL.

Extracellular vesicles and lupus nephritis - New insights into pathophysiology and clinical implications

Lupus nephritis (LN) is a major cause for overall morbidity and mortality in patients with systemic lupus erythematosus (SLE), while its pathogenic mechanisms are still not well understood. Extracellular vesicles (EVs) are membrane vesicles that are released from almost all cell types. EVs can be subdivided into exosomes, microvesicles, and apoptotic bodies. Latest studies have shown that EVs can be released during several cellular events, including cell activation, autophagy, and several types of programed cell death, i.e. apoptosis, necroptosis, pyroptosis, and NETosis. Emerging evidence demonstrates that EVs harbor different bioactive molecules, including nucleic acids, proteins, lipids, cytokines, immune complexes (ICs), complements, and other molecules, some of which may contribute to pathogenesis of autoimmune diseases. EVs can serve as novel information shuttle to mediate local autocrine or paracrine signals to nearby cells, and distant endocrine signals to cells located far away. In LN, EVs may have pathogenic effects by transportation of autoantigens or complements, promotion of IC deposition or complement activation, and stimulation of inflammatory responses, renal tissue injury, or microthrombus formation. Additionally, EVs released from kidney cells may serve as specific biomarkers for diagnosis or monitoring of disease activity and therapeutic efficacy. In this review, we will summarize the latest progress about EV generation from basic research, their potential pathologic effects on LN, and their clinical implications. The cutting-edge knowledge about EV research provides insights into novel therapeutic strategy, new tools for diagnosis or prognosis, and evaluation approaches for treatment effectiveness in LN.

Psychedelics as a novel approach to treating autoimmune conditions

With a rise in the incidence of autoimmune diseases (AiD), health care providers continue to seek out more efficacious treatment approaches for the AiD patient population. Classic serotonergic psychedelics have recently been gaining public and professional interest as novel interventions to a number of mental health afflictions. Psychedelics have also been shown to be able to modulate immune functions, however, while there has been great interest to researching into their psychotherapeutic applications, there has so far been very little exploration into the potential to treat inflammatory and immune-related diseases with these compounds. A handful of studies from a variety of fields suggest that psychedelics do indeed have effects in the body that may attenuate the outcome of AiD. This literature review explores existing evidence that psychedelic compounds may offer a potential novel application in the treatment of pathologies related to autoimmunity. We propose that psychedelics hold the potential to attenuate or even resolve autoimmunity by targeting psychosomatic origins, maladaptive chronic stress responses, inflammatory pathways, immune modulation and enteric microbiome populations.

The Role and Impact of Extracellular Vesicles in the Modulation and Delivery of Cytokines during Autoimmunity

Cytokines and extracellular vesicles are two methods of initiating and maintaining cellular crosstalk. The role of cytokines in the initiation, progression, and resolution of inflammation has been well studied and more so, their pathophysiological role in the development of autoimmune disease. In recent years, the impact of extracellular vesicles on the progression of autoimmunity has become more widely appreciated. In this review, we discuss the mechanisms that allow extracellular vesicles of various sources to modulate cytokine production, and release, and how extracellular vesicles might be involved in the direct delivery and modulation of cytokine levels. Moreover, we explore what challenges are faced by current therapies and the promising future for extracellular vesicles as therapeutic agents in conditions driven by immune dysregulation.

Mir106b-25 and Mir17-92 Are Crucially Involved in the Development of Experimental Neuroinflammation

MicroRNAs (miRNAs) are single-stranded RNA that have key roles in the development of the immune system and are involved in the pathogenesis of various autoimmune diseases. We previously demonstrated that two members of the miR106b-25 cluster and the miR17-92 paralog cluster were upregulated in T regulatory cells from multiple sclerosis (MS) patients. The aim of the present work was to clarify the impact of miR106b-25 and miR17-92 clusters in MS pathogenesis. Here, we show that the mice lacking miR17-92 specifically in CD4⁺ T cells or both total miR106b-25 and miR17-92 in CD4⁺ T cells (double knockout) are protected from Experimental Autoimmune Encephalomyelitis (EAE) development while depletion of miR106b-25 only does not influence EAE susceptibility. We suggest that the absence of miR106b does not protect mice because of a mechanism of compensation of miR17-92 clusters. Moreover, the decrease of neuroinflammation was found to be associated with a significant downregulation of pro-inflammatory cytokines (GM-CSF, IFNγ, and IL-17) in the spinal cord of double knockout EAE mice and a reduction of Th17 inflammatory cells. These results elucidate the effect of miR106b-25 and miR17-92 deletion in MS pathogenesis and suggest that their targeted inhibition may have therapeutic effect on disease course.

Secoemestrin C inhibits activation of NKT/conventional T cells and protects against concanavalin A-induced autoimmune hepatitis in mice

Secoemestrin C is an epitetrathiodioxopiperazine isolated from Aspergillus nidulans, which has only been reported in terms of inhibiting tumor cell proliferation. Here, we determined the immunomodulatory and hepatoprotective effects of secoemestrin C in a mouse model of acute autoimmune hepatitis. In an in vitro assay, purified hepatic mononuclear cells (MNCs) from C57BL/6J mice were stimulated with concanavalin A (Con A) in the presence of secoemestrin C, and cell proliferation and cytokine production were measured. In an in vivo assay, mice with or without secoemestrin C pretreatment were injected with Con A to induce acute hepatitis. The secoemestrin C treatment dose-dependently suppressed cell proliferation and proinflammatory cytokine secretion in Con A-stimulated hepatic MNCs in vitro. In Con A-challenged mice, pre-injection with secoemestrin C significantly decreased the generation of proinflammatory cytokines and ameliorated liver injury. Furthermore, pretreatment with secoemestrin C significantly inhibited the Con A-induced activation of NKT and conventional T cells, and decreased IFN-γ production by these two cell populations. We conclude that secoemestrin C has an immunosuppressive effect on NKT and conventional T cells and has hepatoprotective activity in mouse autoimmune hepatitis. These findings provide new insights into the use of fungus-derived natural products for the treatment of autoimmune diseases.

Diagnosis and treatment of myasthenia gravis

PURPOSE OF REVIEW

This article provides an update on the most recent advances in diagnostic procedures and therapeutic approaches for myasthenia gravis, spanning from autoantibody and neuroelectrophysiological tests as diagnostic tools, to innovative and promising treatments based on biological drugs.

RECENT FINDINGS

Novel studies performed by cell-based assays (CBAs) indicate an improvement in the chance of identifying serum autoantibodies in myasthenic patients. Clinical trials on the use of biological drugs were recently concluded, providing important data on safety and efficacy of eculizumab, efgartigimod and amifampridine phosphate: the first, a complement blocker, showed long-term safety and efficacy in acetylcholine receptor (AChR)-positive myasthenic patients with refractory generalized disease; the second, the neonatal Fc receptor blocker, was well tolerated and clinically effective in both AChR-specific and muscle-specific kinase receptor (MuSK)-positive patients; the third, a blocker of presynaptic potassium channels, was found to be well tolerated and effective in MuSK-positive patients.

SUMMARY

CBAs can lead to a significant reduction of seronegative patients, improving myasthenia gravis diagnostic process. New biological drugs offer innovative approaches to treat myasthenic patients with generalized disease, promising to change the paradigm of treatment and to significantly enhance therapeutic success within a precision medicine framework.

Seminal Plasma Modulates miRNA Expression by Sow Genital Tract Lining Explants

The seminal plasma (SP) modulates the female reproductive immune environment after mating, and microRNAs (miRNAs) could participate in the process. Considering that the boar ejaculate is built by fractions differing in SP-composition, this study evaluated whether exposure of mucosal explants of the sow internal genital tract (uterus, utero-tubal junction and isthmus) to different SP-fractions changed the profile of explant-secreted miRNAs. Mucosal explants retrieved from oestrus sows (n = 3) were in vitro exposed to: Medium 199 (M199, Control) or M199 supplemented (1:40 v/v) with SP from the sperm-rich fraction (SRF), the post-SRF or the entire recomposed ejaculate, for 16 h. After, the explants were cultured in M199 for 24 h to finally collect the media for miRNA analyses using GeneChip miRNA 4.0 Array (Affymetrix). Fifteen differentially expressed (False Discovery Rate (FDR) < 0.05 and Fold-change ≥ 2) miRNAs (11 down- versus 4 up-regulated) were identified (the most in the media of uterine explants incubated with SP from post-SRF). Bioinformatics analysis identified that predicted target genes of dysregulated miRNAs, mainly miR-34b, miR-205, miR-4776-3p and miR-574-5p, were involved in functions and pathways related to immune response. In conclusion, SP is able to elicit changes in the miRNAs profile secreted by female genital tract, ultimately depending SP-composition.

The circRNA-miRNA-mRNA regulatory network in systemic lupus erythematosus

INTRODUCTION/OBJECTIVES

Systemic lupus erythematosus (SLE) was an autoimmune disease with a large variety of clinical manifestations and involving many organs. Its exact etiology was unclear, and studies had shown that T cells may play an important role. In this study, we wished to study the regulatory mechanism of circRNA in the T cells from SLE patients.

METHOD

GSE84655 was retrieved from the GEO database, and the corresponding probe name was converted into an international standard circRNA name by using the practical extraction and report language. The differentially expressed circRNAs (DECs) were analyzed by using R software. Subsequently, we used multiple bioinformatics methods to obtain the target miRNAs of circRNAs and the downstream mRNAs of miRNAs. Finally, a circRNA-miRNA-mRNA regulatory network was constructed and visualized by using Cytoscape 3.6.1 software.

RESULTS

There were a total of 29 DECs that had been identified, including 2 upregulated circRNAs and 27 downregulated circRNAs. After a lot of in-depth analysis, we finally obtained a circRNA-miRNA-mRNA regulatory network consisting of 8 DECs (hsa_circ_0006770, hsa_circ_0002904, hsa_circ_0034044, hsa_circ_0023685, hsa_circ_0049271, hsa_circ_0074491, hsa_circ_0074559, and hsa_circ_0023461), 4 overlap miRNAs (hsa-miR-326, hsa-miR-569, hsa-miR-638, and hsa-miR-1246), and 13 target mRNAs (EPHB3, USH1G,UBE4A, DCAF7, TBL1XR1, SLC27A4, SMO, NAA30, RSBN1, PLAG1, SOX2, GPATCH11, and DYRK1A).

CONCLUSIONS

This study could provide a novel insight into the role of circRNA and the circRNA-miRNA-mRNA regulation network in the SLE. However, it also needed to be verified by subsequent experiments and clinical studies. Key Points • There were 29 DECs (2 up and 27 down) between T cells of SLE and health control. • Hsa-miR-338-3p, hsa-miR-767-3p, and hsa-miR-1827 were the most frequent miRNAs. • We obtained a circRNA-miRNA-mRNA regulatory network for SLE.

Reconstruction and analysis of the aberrant lncRNA-miRNA-mRNA network in systemic lupus erythematosus

OBJECTIVE

A new perspective of determining the pathophysiology of systemic lupus erythematosus (SLE) development is required. The current study explores the aberrant expression of long non-coding RNAs (lncRNA), microRNA (miRNA) and mRNA. The study further constructs and analyses the lncRNA-miRNA-mRNA network to elucidate their gene regulation roles in SLE.

METHOD

We extracted mRNA, lncRNA and miRNA from the whole venous blood of 20 SLE patients and 20 normal control (NC) healthy individuals. A lncRNA-mRNA-miRNA network in SLE was constructed using a bioinformatics approach. Subsequently, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses were performed using the Cytoscape plug-in BinGo, the DAVID database and Cytoscape software to explore the function of mRNAs in this network.

RESULT

A total of 855 mRNA, 7311 lncRNA and 134 miRNA with differentially expressed profiles were identified. Meanwhile, we established a competing endogenous RNA (ceRNA) subnetwork composed of 52 differentially expressed lncRNAs (DElncRNAs), seven differentially expressed miRNAs and 10 differentially expressed mRNAs. We extracted the subnetwork from the ceRNA network and found that three novel miRNAs were key: hsa-miR-145, hsa-miR-17 and hsa-miR-143. We also deduced that the DElncRNAs MIAT and NEAT1 might play crucial roles in the pathogenesis of SLE. The results were verified by bioinformatics analysis.

CONCLUSION

Our results provide a novel perspective for studying lncRNA-related and miRNA-related ceRNA networks in SLE.

miRNA-Mediated Immune Regulation in Islet Autoimmunity and Type 1 Diabetes

The important role of microRNAs as major modulators of various physiological processes, including immune regulation and homeostasis, has been increasingly recognized. Consequently, aberrant miRNA expression contributes to the defective regulation of T cell development, differentiation, and function. This can result in immune activation and impaired tolerance mechanisms, which exert a cardinal function for the onset of islet autoimmunity and the progression to T1D. The specific impact of miRNAs for immune regulation and how miRNAs and their downstream targets are involved in the pathogenesis of islet autoimmunity and T1D has been investigated recently. These studies revealed that increased expression of individual miRNAs is involved in several layers of tolerance impairments, such as inefficient Treg induction and Treg instability. The targeted modulation of miRNAs using specific inhibitors, resulting in improved immune homeostasis, as well as improved methods for the targeting of miRNAs, suggest that miRNAs, especially in T cells, are a promising target for the reestablishment of immune tolerance.

MicroRNAs as disease progression biomarkers and therapeutic targets in experimental autoimmune encephalomyelitis model of multiple sclerosis

Multiple sclerosis is an autoimmune neurodegenerative disease of the central nervous system characterized by pronounced inflammatory infiltrates entering the brain, spinal cord and optic nerve leading to demyelination. Focal demyelination is associated with relapsing-remitting multiple sclerosis, while progressive forms of the disease show axonal degeneration and neuronal loss. The tests currently used in the clinical diagnosis and management of multiple sclerosis have limitations due to specificity and sensitivity. MicroRNAs (miRNAs) are dysregulated in many diseases and disorders including demyelinating and neuroinflammatory diseases. A review of recent studies with the experimental autoimmune encephalomyelitis animal model (mostly female mice 6–12 weeks of age) has confirmed miRNAs as biomarkers of experimental autoimmune encephalomyelitis disease and importantly at the pre-onset (asymptomatic) stage when assessed in blood plasma and urine exosomes, and spinal cord tissue. The expression of certain miRNAs was also dysregulated at the onset and peak of disease in blood plasma and urine exosomes, brain and spinal cord tissue, and at the post-peak (chronic) stage of experimental autoimmune encephalomyelitis disease in spinal cord tissue. Therapies using miRNA mimics or inhibitors were found to delay the induction and alleviate the severity of experimental autoimmune encephalomyelitis disease. Interestingly, experimental autoimmune encephalomyelitis disease severity was reduced by overexpression of miR-146a, miR-23b, miR-497, miR-26a, and miR-20b, or by suppression of miR-182, miR-181c, miR-223, miR-155, and miR-873. Further studies are warranted on determining more fully miRNA profiles in blood plasma and urine exosomes of experimental autoimmune encephalomyelitis animals since they could serve as biomarkers of asymptomatic multiple sclerosis and disease course. Additionally, studies should be performed with male mice of a similar age, and with aged male and female mice.

Determining Immune and miRNA Biomarkers Related to Respiratory Syncytial Virus (RSV) Vaccine Types

Respiratory Syncytial Virus (RSV) causes serious respiratory tract illness and substantial morbidity and some mortality in populations at the extremes of age, i.e., infants, young children, and the elderly. To date, RSV vaccine development has been unsuccessful, a feature linked to the lack of biomarkers available to assess the safety and efficacy of RSV vaccine candidates. We examined microRNAs (miR) as potential biomarkers for different types of RSV vaccine candidates. In this study, mice were vaccinated with a live attenuated RSV candidate that lacks the small hydrophobic (SH) and attachment (G) proteins (CP52), an RSV G protein microparticle (GA2-MP) vaccine, a formalin-inactivated RSV (FI-RSV) vaccine or were mock-treated. Several immunological endpoints and miR expression profiles were determined in mouse serum and bronchoalveolar lavage (BAL) following vaccine priming, boost, and RSV challenge. We identified miRs that were linked with immunological parameters of disease and protection. We show that miRs are potential biomarkers providing valuable insights for vaccine development.

Polymorphism eNOS Glu298Asp modulates the inflammatory response of human peripheral blood mononuclear cells

INTRODUCTION

Nitric oxide is a gaseous radical produced by the nitric oxide endothelial synthase (eNOS) whose most studied physiological action is the vasodilation. However, it also acts in the defense of the organism through the formation of cytotoxic radicals, which can potentiate the inflammatory lesion of the cells. The Glu298Asp is a single nucleotide polymorphism (SNP) in the eNOS gene related to the risk of cardiovascular disease. Blacks present a higher prevalence of hypertension and cardiovascular mortality. Then, we aimed to evaluate the influence of Glu298Asp polymorphism on inflammatory response in vitro and gene expression in blacks.

MATERIAL AND METHODS

Peripheral blood mononuclear cells (PBMC) from blacks with different Glu298Asp genotypes were treated with phytohemagglutinin (PHA), a mitogen and activator of T cells. Oxidative, inflammatory markers, and expression of inflammation genes were evaluated.

RESULTS

The genotype frequencies were TT 6.7%; TG 29.3% and GG 64.0%. Activation of PBMCs with 125 μg of PHA modulated the expression of inflammatory genes and increased levels of inflammatory cytokines. The T allele showed increased susceptibility to inflammation (higher levels of interleukin 1, interleukin 6 and tumor necrosis factor alpha; p < 0.001). The G allele exhibited protection through higher levels of nitric oxide (p < 0.001) and fewer inflammatory cytokines.

CONCLUSION

Despite methodological limitations related to in vitro assays, the whole of results suggested that Glu298Asp modulates inflammatory genes, the T allele is more susceptible to inflammation and the G allele is protective.

Fatigue, Sleep, and Autoimmune and Related Disorders

Profound and debilitating fatigue is the most common complaint reported among individuals with autoimmune disease, such as systemic lupus erythematosus, multiple sclerosis, type 1 diabetes, celiac disease, chronic fatigue syndrome, and rheumatoid arthritis. Fatigue is multi-faceted and broadly defined, which makes understanding the cause of its manifestations especially difficult in conditions with diverse pathology including autoimmune diseases. In general, fatigue is defined by debilitating periods of exhaustion that interfere with normal activities. The severity and duration of fatigue episodes vary, but fatigue can cause difficulty for even simple tasks like climbing stairs or crossing the room. The exact mechanisms of fatigue are not well-understood, perhaps due to its broad definition. Nevertheless, physiological processes known to play a role in fatigue include oxygen/nutrient supply, metabolism, mood, motivation, and sleepiness-all which are affected by inflammation. Additionally, an important contributing element to fatigue is the central nervous system-a region impacted either directly or indirectly in numerous autoimmune and related disorders. This review describes how inflammation and the central nervous system contribute to fatigue and suggests potential mechanisms involved in fatigue that are likely exhibited in autoimmune and related diseases.