Pro-inflammatory Cytokine Pathways Research Articles

Single Nucleotide Polymorphisms as Biomarker Predictors of Oral Mucositis Severity in Head and Neck Cancer Patients Submitted to Combined Radiation Therapy and Chemotherapy: A Systematic Review.

Single Nucleotide Polymorphisms (SNPs) are the most common type of genetic variation found in an individual's DNA sequences. SNPs can occur in both coding and non-coding regions of the genome and can affect gene expression, protein function, and disease susceptibility. In this systematic review, we evaluate the potential of SNPs as biomarkers in the assessment of oral mucositis (OM) severity in head and neck cancer (HNC) patients treated with concomitant chemoradiation (CRT). The study selection process involved screening 66 articles from different platforms, and after removing duplicates and excluding articles that did not meet the eligibility criteria, 23 articles were included for full-text evaluation. Among them, genes from several pathways were analyzed. The DNA damage repair pathways had the highest number of genes studied. The most frequently analyzed gene was XRCC1. The proinflammatory cytokine pathways evaluated were TNF, with three articles, and NF-κB, with one article. Most included studies showed a potential association between certain SNPs and high-grade mucositis. We conclude that SNPs can be used as possible biomarkers for the assessment of OM intensity in HNC patients, and further research is needed to explore the potential of SNPs in personalized medicine for HNC treatment.

Peripheral memory B cells in multiple sclerosis vs. double negative B cells in neuromyelitis optica spectrum disorder: disease driving B cell subsets during CNS inflammation.

B cells are fundamental players in the pathophysiology of autoimmune diseases of the central nervous system, such as multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD). A deeper understanding of disease-specific B cell functions has led to the differentiation of both diseases and the development of different treatment strategies. While NMOSD is strongly associated with pathogenic anti-AQP4 IgG antibodies and proinflammatory cytokine pathways, no valid autoantibodies have been identified in MS yet, apart from certain antigen targets that require further evaluation. Although both diseases can be effectively treated with B cell depleting therapies, there are distinct differences in the peripheral B cell subsets that influence CNS inflammation. An increased peripheral blood double negative B cells (DN B cells) and plasmablast populations has been demonstrated in NMOSD, but not consistently in MS patients. Furthermore, DN B cells are also elevated in rheumatic diseases and other autoimmune entities such as myasthenia gravis and Guillain-Barré syndrome, providing indirect evidence for a possible involvement of DN B cells in other autoantibody-mediated diseases. In MS, the peripheral memory B cell pool is affected by many treatments, providing indirect evidence for the involvement of memory B cells in MS pathophysiology. Moreover, it must be considered that an important effector function of B cells in MS may be the presentation of antigens to peripheral immune cells, including T cells, since B cells have been shown to be able to recirculate in the periphery after encountering CNS antigens. In conclusion, there are clear differences in the composition of B cell populations in MS and NMOSD and treatment strategies differ, with the exception of broad B cell depletion. This review provides a detailed overview of the role of different B cell subsets in MS and NMOSD and their implications for treatment options. Specifically targeting DN B cells and plasmablasts in NMOSD as opposed to memory B cells in MS may result in more precise B cell therapies for both diseases.

Transcriptional profiling upon T cell stimulation reveals down-regulation of inflammatory pathways in T and B cells in SLE versus Sjögren’s syndrome

Systemic lupus erythematosus (SLE) and primary Sjögren’s syndrome (pSS) share clinical as well as pathogenic similarities. Although previous studies suggest various abnormalities in different immune cell compartments, dedicated cell-type specific transcriptomic signatures are often masked by patient heterogeneity. Here, we performed transcriptional profiling of isolated CD4, CD8, CD16 and CD19 lymphocytes from pSS and SLE patients upon T cell stimulation, in addition to a steady-state condition directly after blood drawing, in total comprising 581 sequencing samples. T cell stimulation, which induced a pronounced inflammatory response in all four cell types, gave rise to substantial re-modulation of lymphocyte subsets in the two autoimmune diseases compared to healthy controls, far exceeding the transcriptomic differences detected at steady-state. In particular, we detected cell-type and disease-specific down-regulation of a range of pro-inflammatory cytokine and chemokine pathways. Such differences between SLE and pSS patients are instrumental for selective immune targeting by future therapies.

The Effect of secretome-hypoxia mesenchymal-stem-cells and vitamin-d3 in type-2 diabetes-mellitus induced periodontitis rats

Background: A systemic metabolic disorder by insulin resistance, type-2 diabetes mellitus (T2DM), is characterised by an increased level of reactive oxygen species (ROS) and decreased superoxide dismutase (SOD), which is associated with the activation of proinflammatory cytokine pathways such as tumor necrosis (TNF)-α. This condition usually stimulates inflammation of the periodontal tissue (periodontitis). Vitamin-D3 can inhibit the release of inflammatory mediator and reduce the risk of chronic periodontitis. Purpose this study to determine the effect of the secretome-hypoxia mesenchymal-stem-cells (SH-MSCs)-Vitamin-D3 combination on the expression of SOD, IL-10, and TNF-α genes in T2DM periodontitis-induced rats.
 Method: 30 rats were randomly divided into five groups; normal sham condition, positive control, SH-MSCs group, vitamin-D3 group, and combination of SH-MSCs and vitamin D3 group. SH-MSCs were injected at doses of 150 uL in the gingival. In addition, vitamin D3 5000 IU 2.25 mcg were administrated orally. After 35 days, all rats were sacrificed, and qRT-PCR from gingival tissue was performed to identify the expression of SOD, IL-10 and TNF-α genes 
 Results: The results a significant increase in SOD and IL-10 gene expression (p

Circulating exosomes from brain death and cardiac death donors have distinct molecular and immunologic properties: A pilot study.

Comparison of donation after brain death (DBD) and donation after cardiac death (DCD) lung tissue before transplantation have demonstrated activation of pro-inflammatory cytokine pathway in DBD donors. The molecular and immunological properties of circulating exosomes from DBD and DCD donors were not previously described. We collected plasma from 18 deceased donors (12 DBD and six DCD). Cytokines were analyzed by 30-Plex luminex Panels. Exosomes were analyzed for liver self-antigen (SAg), Transcription Factors and HLA class II (HLA-DR/DQ) using western blot. C57BL/6 animals were immunized with isolated exosomes to determine strength and magnitude of immune responses. Interferon (IFN)-γ and tumor necrosis factor-α producing cells were quantified by ELISPOT, specific antibodies to HLA class II antigens were measured by ELISA RESULTS: We demonstrate increased plasma levels of IFNγ, EGF, EOTAXIN, IP-10, MCP-1, RANTES, MIP-β, VEGF, and interleukins - 6/8 in DBD plasma versus DCD. MiRNA isolated from exosome of DBD donors demonstrated significant increase in miR-421, which has been reported to correlate with higher level of Interleukin-6. Higher levels of liver SAg Collagen III (p=.008), pro-inflammatory transcription factors (NF-κB, p<.05; HIF1α, p=.021), CIITA (p=.011), and HLA class II (HLA-DR, p=.0003 and HLA-DQ, p=.013) were detected in exosomes from DBD versus DCD plasma. The circulating exosomes isolated from DBD donors were immunogenic in mice and led to the development of Abs to HLA-DR/DQ. This study provides potential new mechanisms by which DBD organs release exosomes that can activate immune pathways leading to cytokine release and allo-immune response.

Cytokines in Spondyloarthritis and Inflammatory Bowel Diseases: From Pathogenesis to Therapeutic Implications.

Spondyloarthritis and inflammatory bowel diseases are chronic immune disorders of the joints and the gut that often coexist in the same patient, increasing the burden of each disorder, worsening patients' quality of life, and influencing therapeutic strategies. Genetic predisposition, environmental triggers, microbiome features, immune cell trafficking, and soluble factors such as cytokines contribute to the pathogenesis of both articular and intestinal inflammation. Most of the molecular targeted biological therapies developed over the last two decades were based on evidence that specific cytokines may be involved in these immune diseases. Despite pro-inflammatory cytokine pathways sharing the pathogenesis of both articular and gut diseases (i.e., tumor necrosis factor and interleukin-23), several other cytokines (i.e., interleukin-17) may be differently involved in the tissue damage process, depending on the specific disease and the organ involved in inflammation, making difficult the identification of a therapeutic plan that is efficacious for both inflammatory manifestations. In this narrative review, we comprehensively summarize the current knowledge on cytokine involvement in spondyloarthritis and inflammatory bowel diseases, underlining similarities and differences among their pathogenetic pathways; finally, we provide an overview of current and potential future treatment strategies to simultaneously target both articular and gut immune disorders.

Impaired Intestinal Permeability of Tricellular Tight Junctions in Patients with Irritable Bowel Syndrome with Mixed Bowel Habits (IBS-M).

The underlying pathophysiology of irritable bowel syndrome (IBS) is still unclear. Our aim was to investigate the pathophysiological mechanisms of diarrhea, constipation, and antigen uptake in mixed-type IBS (IBS-M). Colonoscopic biopsies were obtained from IBS-M patients. Epithelial transport and barrier function of colonic mucosae were characterized in Ussing chambers using impedance spectroscopy. Mucosal permeability to macromolecules was measured. Western blotting for tight junction (TJ) proteins was performed and their subcellular localization was visualized by confocal microscopy. RNA-sequencing was performed for gene expression and signaling pathway analysis. In IBS-M, epithelial resistance and ENaC-dependent sodium absorption were unchanged, while short-circuit current reflecting chloride secretion was reduced. Concomitantly, epithelial permeability for fluorescein and FITC-dextran-4000 increased. TJ protein expression of occludin decreased, whereas claudins were unaltered. Confocal microscopy revealed the de-localization of tricellulin from tricellular TJs. Involved pathways were detected as proinflammatory cytokine pathways, LPS, PGE2, NGF, and vitamin D. Decreased anion secretion explains constipation in IBS-M, while ion permeability and sodium absorption were unaltered. Reduced occludin expression resulted in the delocalization of tricellulin from the tricellular TJ, leading to increased macromolecular permeability that contributes to antigen influx into the mucosa and perpetuates a low-grade inflammatory process.

Disruption of retinal inflammation and the development of diabetic retinopathy in mice by a CD40-derived peptide or mutation of CD40 in Müller cells

Aims/hypothesisCD40 expressed in Müller cells is a central driver of diabetic retinopathy. CD40 causes phospholipase Cγ1 (PLCγ1)-dependent ATP release in Müller cells followed by purinergic receptor (P2X7)-dependent production of proinflammatory cytokines in myeloid cells. In the diabetic retina, CD40 and P2X7 upregulate a broad range of inflammatory molecules that promote development of diabetic retinopathy. The molecular event downstream of CD40 that activates the PLCγ1–ATP–P2X7–proinflammatory cytokine cascade and promotes development of diabetic retinopathy is unknown. We hypothesise that disruption of the CD40-driven molecular events that trigger this cascade prevents/treats diabetic retinopathy in mice.MethodsB6 and transgenic mice with Müller cell-restricted expression of wild-type (WT) CD40 or CD40 with mutations in TNF receptor-associated factor (TRAF) binding sites were made diabetic using streptozotocin. Leucostasis was assessed using FITC-conjugated concanavalin A. Histopathology was examined in the retinal vasculature. Expression of inflammatory molecules and phospho-Tyr783 PLCγ1 (p-PLCγ1) were assessed using real-time PCR, immunoblot and/or immunohistochemistry. Release of ATP and cytokines were measured by ATP bioluminescence and ELISA, respectively.ResultsHuman Müller cells with CD40 ΔT2,3 (lacks TRAF2,3 binding sites) were unable to phosphorylate PLCγ1 and release ATP in response to CD40 ligation, and could not induce TNF-α/IL-1β secretion in bystander myeloid cells. CD40–TRAF signalling acted via Src to induce PLCγ1 phosphorylation. Diabetic mice in which WT CD40 in Müller cells was replaced by CD40 ΔT2,3 failed to exhibit phosphorylation of PLCγ1 in these cells and upregulate P2X7 and TNF-α in microglia/macrophages. P2x7 (also known as P2rx7), Tnf-α (also known as Tnf), Il-1β (also known as Il1b), Nos2, Icam-1 (also known as Icam1) and Ccl2 mRNA were not increased in these mice and the mice did not develop retinal leucostasis and capillary degeneration. Diabetic B6 mice treated intravitreally with a cell-permeable peptide that disrupts CD40–TRAF2,3 signalling did not exhibit either upregulation of P2X7 and inflammatory molecules in the retina or leucostasis.Conclusions/interpretationCD40–TRAF2,3 signalling activated the CD40–PLCγ1–ATP–P2X7–proinflammatory cytokine pathway. Src functioned as a link between CD40–TRAF2,3 and PLCγ1. Replacing WT CD40 with CD40 ΔT2,3 impaired activation of PLCγ1 in Müller cells, upregulation of P2X7 in microglia/macrophages, upregulation of a broad range of inflammatory molecules in the diabetic retina and the development of diabetic retinopathy. Administration of a peptide that disrupts CD40–TRAF2,3 signalling reduced retinal expression of inflammatory molecules and reduced leucostasis in diabetic mice, supporting the therapeutic potential of pharmacological inhibition of CD40–TRAF2,3 in diabetic retinopathy.Graphical abstract

JAK inhibitors in difficult-to-treat adult-onset Still's disease and systemic-onset juvenile idiopathic arthritis.

Excessive and inappropriate production of pro-inflammatory cytokines plays a key role in Still's disease. Janus kinase inhibitor (JAKi) agents mainly block pro-inflammatory cytokine pathways, notably IL-6 and IFN. The objective was to assess the efficacy and safety of JAKi agents in difficult-to-treat systemic JIA or adult-onset Still's disease (AOSD). This retrospective study was based on a national survey conducted in the departments of rheumatology, paediatric rheumatology and internal medicine of French hospitals regarding systemic JIA and AOSD patients who received JAKi agents. The data were collected with a standardized questionnaire and analysed at different times (treatment initiation, months 1, 3 and 6 and the end of follow-up). Nine patients (seven adults) were included. All patients showed inadequate response to CS or conventional synthetic or biologic DMARDs. Baricitinib was used in five patients, ruxolitinib in two, tofacitinib in two and upadacitinib in one. A JAKi was used combined with CS in all but two patients. A JAKi was associated with anakinra and CS in one patient, and with MTX, anakinra and CS in another. The median (range) follow-up was 16 (1-33) months. Two cases out of nine showed complete remission, 3/9 partial response and 4/9 treatment failure. At the last visit, CS could be decreased but not stopped. Tolerance of the JAKi was acceptable (no severe adverse events). JAKi agents may be a therapeutic option for some patients with difficult-to-treat Still's disease, especially those with partial response to medium- or high-dose CS or biologics.

Mechanisms of impaired muscle repair following influenza infection in aged mice.

Abstract Older adults are susceptible to infectious diseases including Influenza (flu), due to widely accepted declines in immune response with age. Flu infection in older adults commonly results in hospitalization and catastrophic disability, leading to loss of independence. Previous findings demonstrate that flu infection induces severe and prolonged muscle injury in aged mice. We aimed to explore the effects of flu infection on skeletal muscle gene expression and immune cell populations to elucidate mechanisms of flu-induced disability in older adults. Young and aged C57BL/6 male mice were infected with a sublethal dose of PR8 (H1N1) influenza. Gastrocnemius muscles were harvested for RNA sequencing, confocal microscopy, and flow cytometry. Our findings showed differential gene expression changes between young and aged mice, including downregulation of muscle regeneration and organization genes and upregulation proinflammatory cytokine and migratory cell pathways in aged muscle. Pathway analysis revealed significant increases in T cell activation pathways in the aged muscle. Confocal microcopy confirmed increased leukocytes (CD45+) and T cells (CD3+) intramuscularly following flu infection. Flow cytometric analyses confirmed that aged mice have increased infiltrating CD8 T cells during infection compared to young mice, while young muscle have increased infiltrating regulatory T cells (Tregs) compared to their aged counterparts. Further analysis suggested that differences in IL-33 levels between young and aged mice influence these infiltrating populations. Future research is necessary to determine if IL-33 supplementation may prevent or ameliorate flu-induced disability in older adults. Supported by NIH/NIA R01 AG051647 (Co-I) NIH/NIA R01 AR075346 (Co-I) NIH/NIA R33 AG061456 (Co-I) NIH/NIA R21 AG071292 (Co-I) American Federation for Aging Research Reboot (PI)

Interleukin-17 contributes to Ross River virus-induced arthritis and myositis.

Arthritogenic alphaviruses are mosquito-borne viruses that are a major cause of infectious arthropathies worldwide, and recent outbreaks of chikungunya virus and Ross River virus (RRV) infections highlight the need for robust intervention strategies. Alphaviral arthritis can persist for months after the initial acute disease, and is mediated by cellular immune responses. A common strategy to limit inflammation and pathology is to dampen the overwhelming inflammatory responses by modulating proinflammatory cytokine pathways. Here, we investigate the contribution of interleukin-17 (IL-17), a cytokine involved in arthropathies such as rheumatoid arthritis, in the development RRV-induced arthritis and myositis. IL-17 was quantified in serum from RRV-infected patients, and mice were infected with RRV and joints and muscle tissues collected to analyse cellular infiltrates, tissue mRNA, cytokine expression, and joint and muscle histopathology. IL-17 expression was increased in musculoskeletal tissues and serum of RRV-infected mice and humans, respectively. IL-17–producing T cells and neutrophils contributed to the cellular infiltrate in the joint and muscle tissue during acute RRV disease in mice. Blockade of IL-17A/F using a monoclonal antibody (mAb) reduced disease severity in RRV-infected mice and led to decreased proinflammatory proteins, cellular infiltration in synovial tissues and cartilage damage, without affecting viral titers in inflamed tissues. IL-17A/F blockade triggered a shift in transcriptional profile of both leukocyte infiltrates and musculoskeletal stromal cells by downregulating proinflammatory genes. This study highlights a previously uncharacterized role for an effector cytokine in alphaviral pathology and points towards potential therapeutic benefit in targeting IL-17 to treat patients presenting with RRV-induced arthropathy.

Multiple Myeloma Patient Tumors With High Levels of Cereblon Exon-10 Deletion Splice Variant Upregulate Clinically Targetable Pro-Inflammatory Cytokine Pathways.

Immunomodulatory drugs (IMiDs), including lenalidomide and pomalidomide, are used in the routine treatment for multiple myeloma (MM) patients. Cereblon (CRBN) is the direct molecular target of IMiDs. While CRBN is not an essential gene for MM cell proliferation, the frequency of CRBN genetic aberrations, including mutation, copy number loss, and exon-10 (which includes a portion of the IMiD-binding domain) splicing, have been reported to incrementally increase in later-line patients. CRBN exon-10 splicing has also been shown to be associated with decreased progression-free survival in both newly diagnosed and relapsed refractory MM patients. Although we did not find significant general splicing defects among patients with CRBN exon-10 splice variant when compared to those expressing the full-length transcript, we identified upregulated TNFA signaling via NFKB, inflammatory response, and IL-10 signaling pathways in patients with exon-10 splice variant across various data sets—all potentially promoting tumor growth via chronic growth signals. We examined master regulators that mediate transcriptional programs in CRBN exon-10 splice variant patients and identified BATF, EZH2, and IKZF1 as the key candidates across the four data sets. Upregulated downstream targets of BATF, EZH2, and IKZF1 are components of TNFA signaling via NFKB, IL2/STAT5 signaling pathways, and IFNG response pathways. Previously, BATF-mediated transcriptional regulation was associated with venetoclax sensitivity in MM. Interestingly, we found that an EZH2 sensitivity gene expression signature also correlated with high BATF or venetoclax sensitivity scores in these tumors. Together, these data provide a rationale for investigating EZH2 inhibitors or venetoclax in combination with the next generation CRBN-targeting agents, such as CELMoDs, for patients overexpressing the CRBN exon-10 splice variant.

Proteomics reveals disturbances in the immune response and energy metabolism of monocytes from patients with septic shock

Sepsis results from a dyshomeostatic response to infection, which may lead to hyper or hypoimmune states. Monocytes are central regulators of the inflammatory response, but our understanding of their role in the genesis and resolution of sepsis is still limited. Here, we report a comprehensive exploration of monocyte molecular responses in a cohort of patients with septic shock via proteomic profiling. The acute stage of septic shock was associated with an impaired inflammatory phenotype, indicated by the down-regulation of MHC class II molecules and proinflammatory cytokine pathways. Simultaneously, there was an up-regulation of glycolysis enzymes and a decrease in proteins related to the citric acid cycle and oxidative phosphorylation. On the other hand, the restoration of immunocompetence was the hallmark of recovering patients, in which an upregulation of interferon signaling pathways was a notable feature. Our results provide insights into the immunopathology of sepsis and propose that, pending future studies, immunometabolism pathway components could serve as therapeutic targets in septic patients.

Survival and transcriptomic responses to different Perkinsus marinus exposure methods in an Eastern oyster family

The parasite Perkinsus marinus, which causes Dermo disease, affects Eastern oyster (Crassostrea virginica) survival and is responsible for substantial losses to aquaculture production. Controlled laboratory challenges enable definition and measurement of disease response phenotypes as well as characterization of gene expression patterns during the infection process. The method of parasite exposure and severity of infection likely affect response measures and exploring variation among them can enhance our understanding of this host-parasite interaction. Here we compared response traits and global expression patterns over time for a selectively bred Eastern oyster family exposed to P. marinus via either suspension feeding or direct injection to elucidate mechanisms determining survival. All exposed oysters (n = 56 per group) received a dose of 5 × 106 cultured P. marinus cells g−1 wet tissue weight but oysters in the injected group had higher initial parasite load and significantly reduced survival probability compared to the fed group. Using RNAseq, we identified differentially expressed transcripts between fed and control animals 6 h after exposure and between fed and injected groups at 36 h, 7 d, and 28 d post exposure. Immediately after infection, caspase-8 and transcripts associated with mediating cell damage from reactive oxygen species were upregulated in the fed group compared to unchallenged controls. The comparison between fed and injected groups early in the infection process revealed increased innate immune activity and overexpression of transcripts involved in proinflammatory cytokine pathways, including toll-like receptor 4 and TNF receptor-associated factor 6-like protein, in the injected group. Later in the infection process, the fed group expressed transcripts associated with growth, specifically microtubule-based processes, at a higher level than the injected group. This study demonstrates that dosing method influences initial parasite load, survival, and transcriptomic response to Dermo disease and highlights the importance of considering exposure method when interpreting interactions between P. marinus and the Eastern oyster.

The Network of Inflammatory Mechanisms in Lupus Nephritis.

Several signaling pathways are involved in the progression of kidney disease in humans and in animal models, and kidney disease is usually due to the sustained activation of these pathways. Some of the best understood pathways are specific proinflammatory cytokine and protein kinase pathways (e.g., protein kinase C and mitogen-activated kinase pathways, which cause cell proliferation and fibrosis and are associated with angiotensin II) and transforming growth factor-beta (TGF-β) signaling pathways (e.g., the TGF-β signaling pathway, which leads to increased fibrosis and kidney scarring. It is thus necessary to continue to advance our knowledge of the pathogenesis and molecular biology of kidney disease and to develop new treatments. This review provides an update of important findings about kidney diseases (including diabetic nephropathy, lupus nephritis, and vasculitis, i.e., vasculitis with antineutrophilic cytoplasmic antibodies). New disease targets, potential pathological pathways, and promising therapeutic approaches from basic science to clinical practice are presented, and the blocking of JAK/STAT and TIM-1/TIM-4 signaling pathways as potential novel therapeutic agents in lupus nephritis is discussed.

Hemorrhagic encephalopathy associated with COVID-19

The mechanisms for neurological complications of COVID-19, the disease caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), are not yet well understood. We present a critically ill man with a COVID-19-associated hemorrhagic encephalopathy. SARS-CoV-2 RNA was not detected in cerebrospinal fluid (CSF) or blood. CSF analyses suggested dysregulation of pro-inflammatory cytokine pathways, particularly tumor necrosis factor-α and interleukin-6, consistent with a cytokine release syndrome. The patient gradually recovered with supportive care and neurological rehabilitation. Awareness of this clinical entity may facilitate the identification of patients with a potentially remediable cause of encephalopathy in COVID-19.

Linking genetic variation with epigenetic profiles in Sjögren's syndrome

DNA methylation represents an important regulatory event governing gene expression that is dysregulated in Sjögren's syndrome (SjS) and a number of autoimmune/inflammatory diseases. As disease-associated single-nucleotide polymorphisms (SNPs) have relevance in controlling DNA methylation, 94 non-HLA SjS-SNPs were investigated, among them 57 (60.6%) with widespread effects on 197 individual DNA methylation quantitative trait loci (meQTL) were selected. Typically, these SNPs are intronic, possess an active promoter histone mark, and control cis-meQTLs located around transcription start sites. Interplay is independent of the physical distance between SNPs and meQTLs. Using epigenome-wide association study datasets, SjS-meQTLs were characterized (41 genes and 13 DNA methylation CpG motifs) and for the most part map to a pro-inflammatory cytokine pathway, which is important for the control of DNA methylation in autoimmune diseases. In conclusion, exploring meQTLs represents a valuable tool to predict and investigate downstream effects of genetic factors in complex diseases such as SjS.

A network-based approach to uncover microRNA-mediated disease comorbidities and potential pathobiological implications

Disease–disease relationships (e.g., disease comorbidities) play crucial roles in pathobiological manifestations of diseases and personalized approaches to managing those conditions. In this study, we develop a network-based methodology, termed meta-path-based Disease Network (mpDisNet) capturing algorithm, to infer disease–disease relationships by assembling four biological networks: disease–miRNA, miRNA–gene, disease–gene, and the human protein–protein interactome. mpDisNet is a meta-path-based random walk to reconstruct the heterogeneous neighbors of a given node. mpDisNet uses a heterogeneous skip-gram model to solve the network representation of the nodes. We find that mpDisNet reveals high performance in inferring clinically reported disease–disease relationships, outperforming that of traditional gene/miRNA-overlap approaches. In addition, mpDisNet identifies network-based comorbidities for pulmonary diseases driven by underlying miRNA-mediated pathobiological pathways (i.e., hsa-let-7a- or hsa-let-7b-mediated airway epithelial apoptosis and pro-inflammatory cytokine pathways) as derived from the human interactome network analysis. The mpDisNet offers a powerful tool for network-based identification of disease–disease relationships with miRNA-mediated pathobiological pathways.

Grape Seed Extract Eliminates Visceral Allodynia and Colonic Hyperpermeability Induced by Repeated Water Avoidance Stress in Rats.

Grape seed extract (GSE) is rich in polyphenols composed mainly of proanthocyanidins, which are known to attenuate proinflammatory cytokine production. Repeated water avoidance stress (WAS) induces visceral allodynia and colonic hyperpermeability via toll-like receptor 4 (TLR4) and proinflammatory cytokine pathways, which is a rat irritable bowel syndrome (IBS) model. Thus, we explored the effects of GSE on repeated WAS (1 h for 3 days)-induced visceral allodynia and colonic hyperpermeability in Sprague-Dawley rats. Paracellular permeability, as evaluated by transepithelial electrical resistance and flux of carboxyfluorescein, was analyzed in Caco-2 cell monolayers treated with interleukin-6 (IL-6) and IL-1β. WAS caused visceral allodynia and colonic hyperpermeability, and intragastric administration of GSE (100 mg/kg, once daily for 11 days) inhibited these changes. Furthermore, GSE also suppressed the elevated colonic levels of IL-6, TLR4, and claudin-2 caused by WAS. Paracellular permeability was increased in Caco-2 cell monolayers in the presence of IL-6 and IL-1β, which was inhibited by GSE. Additionally, GSE suppressed the claudin-2 expression elevated by cytokine stimulation. The effects of GSE on visceral changes appear to be evoked by suppressing colonic TLR4-cytokine signaling and maintaining tight junction integrity. GSE may be useful for treating IBS.

Time Course of Blood and Brain Cytokine/Chemokine Levels Following Adolescent Alcohol Exposure and Withdrawal in Rats.

Adolescence is a critical period for neural development, and alcohol exposure during adolescence can lead to an elevated risk for health consequences as well as alcohol use disorders. Clinical and experimental data suggest that chronic alcohol exposure may produce immunomodulatory effects that can lead to the activation of pro-inflammatory cytokine pathways as well as microglial markers. The present study evaluated, in brain and blood, the effects of adolescent alcohol exposure and withdrawal on microglia and on the most representative pro- and anti-inflammatory cytokines and major chemokines that can contribute to the establishing of a neuroinflammatory environment. Wistar rats (males, n=96) were exposed to ethanol (EtOH) vapors, or air control, for 5weeks over adolescence (PD22-PD58). Brains and blood samples were collected at 3 time points: (i) after 35days of vapor/air exposure (PD58); (ii) after 1day of withdrawal (PD59), and (iii) 28days after withdrawal (PD86). The ionized calcium-binding adapter molecule 1 (Iba-1) was used to index microglial activation, and cytokine/chemokine responses were analyzed using magnetic bead panels. After 35days of adolescent vapor exposure, a significant increase in Iba-1 immunoreactivity was seen in amygdala, frontal cortex, hippocampus, and substantia nigra. However, Iba-1 density returned to control levels at both 1day and 28days of withdrawal except in the hippocampus where Iba-1 density was significantly lower than controls. In serum, adolescent EtOH exposure induced a reduction in IL-13 and an increase in fractalkine at day 35. After 1day of withdrawal, IL-18 was reduced, and IP-10 was elevated, whereas both IP-10 and IL-10 were elevated at 28days following withdrawal. In the frontal cortex, adolescent EtOH exposure induced an increase in IL-1β at day 35, and 28days of withdrawal, and IL-10 was increased after 28days of withdrawal. These data demonstrate that EtOH exposure during adolescence produces significant microglial activation; however, inflammatory markers seen in the blood appear to differ from those observed in the brain.