Immune System Signaling Research Articles

Prenatal Zinc Deficient Mice as a Model for Autism Spectrum Disorders.

Epidemiological studies have shown a clear association between early life zinc deficiency and Autism Spectrum Disorders (ASD). In line with this, mouse models have revealed prenatal zinc deficiency as a profound risk factor for neurobiological and behavioral abnormalities in the offspring reminiscent of ASD behavior. From these studies, a complex pathology emerges, with alterations in the gastrointestinal and immune system and synaptic signaling in the brain, as a major consequence of prenatal zinc deficiency. The features represent a critical link in a causal chain that leads to various neuronal dysfunctions and behavioral phenotypes observed in prenatal zinc deficient (PZD) mice and probably other mouse models for ASD. Given that the complete phenotype of PZD mice may be key to understanding how non-genetic factors can modify the clinical features and severity of autistic patients and explain the observed heterogeneity, here, we summarize published data on PZD mice. We critically review the emerging evidence that prenatal zinc deficiency is at the core of several environmental risk factors associated with ASD, being mechanistically linked to ASD-associated genetic factors. In addition, we highlight future directions and outstanding questions, including potential symptomatic, disease-modifying, and preventive treatment strategies.

NLRX1 Deficiency Alters the Gut Microbiome and Is Further Exacerbated by Adherence to a Gluten-Free Diet.

Patients with gluten sensitivities present with dysbiosis of the gut microbiome that is further exacerbated by a strict adherence to a gluten-free diet (GFD). A subtype of patients genetically susceptible to gluten sensitivities are Celiac Disease (CeD) patients, who are carriers of the HLA DR3/DQ2 or HLA DR4/DQ8 haplotypes. Although 85-95% of all CeD patients carry HLA DQ2, up to 25-50% of the world population carry this haplotype with only a minority developing CeD. This suggests that CeD and other gluten sensitivities are mediated by factors beyond genetics. The contribution of innate immune system signaling has been generally understudied in the context of gluten sensitivities. Thus, here we examined the role of NOD-like receptors (NLRs), a subtype of pattern recognition receptors, in maintaining the composition of the gut microbiome in animals maintained on a GFD. Human transcriptomics data revealed significant increases in the gene expression of multiple NLR family members, across functional groups, in patients with active CeD compared to control specimens. However, NLRX1 was uniquely down-regulated during active disease. NLRX1 is a negative regulatory NLR that functions to suppress inflammatory signaling and has been postulate to prevent inflammation-induced dysbiosis. Using Nlrx1-/- mice maintained on either a normal or gluten-free diet, we show that loss of NLRX1 alters the microbiome composition, and a distinctive shift further ensues following adherence to a GFD, including a reciprocal loss of beneficial microbes and increase in opportunistic bacterial populations. Finally, we evaluated the functional impact of an altered gut microbiome by assessing short- and medium-chain fatty acid production. These studies revealed significant differences in a selection of metabolic markers that when paired with 16S rRNA sequencing data could reflect an overall imbalance and loss of immune system homeostasis in the gastrointestinal system.

Prognostic value of protein biomarkers in liver transplantation: A systematic review.

Liver transplantation is currently the preferred method for the treatment of advanced liver disease and early-stage hepatocellular carcinoma (HCC). Although advances in surgical techniques, immunosuppressive drugs and postoperative management have reduced the incidence of postoperative complications, how to effectively predict or diagnose postoperative complications earlier and reduce their incidence is still a clinical concern. We performed a comprehensive proteomics literature research to identified protein biomarkers in complications after liver transplantation. Seventeen studies met the inclusion criteria including ischemia reperfusion injury (IRI) (n=4), acute rejection (AR) (n=4), renal dysfunction (n=4), HCC recurrence (n=2), primary graft dysfunction (PGD) (n=1), infection (n=1), and liver fibrosis (n=1). A total of 625 differentially expressed proteins (DEPs) have been reported between postoperative complications and controls, of which 63 have been validated by quantitative protein expression and 26 have been reported by at least two studies and showed consistently changes. The results of the bioinformation analysis show that the immune system, especially the innate immune system and cytokine signaling in immune system, is an important protein-mediated pathway that affects the prognosis of liver transplantation.

Immunogenic Cell Death-Relevant Damage-Associated Molecular Patterns and Sensing Receptors in Triple-Negative Breast Cancer Molecular Subtypes and Implications for Immunotherapy.

ObjectivesTriple-negative breast cancer (TNBC) is defined as a highly aggressive type of breast cancer which lacks specific biomarkers and drug targets. Damage-associated molecular pattern (DAMP)-induced immunogenic cell death (ICD) may influence the outcome of immunotherapy for TNBC patients. This study aims to develop a DAMPs gene signature to classify TNBC patients and to further predict their prognosis and immunotherapy outcome.MethodsWe identified the DAMPs-associated subtypes of 330 TNBCs using K-means analysis. Differences in immune status, genomic alterations, and predicted immunotherapy outcome were compared among each subtype.ResultsA total of 330 TNBCs were divided into three subtypes according to DAMPs gene expression: the nuclear DAMPs subtype, featuring the upregulation of nuclear DAMPs; the inflammatory DAMPs subtype, characterized by the gene set enrichment of the adaptive immune system and cytokine signaling in the immune system; and the DAMPs-suppressed subtype, having the lowest level of ICD-associated DAMPs. Among them, the inflammatory subtype patients had the most favorable survival, while the DAMPs-suppressed subtype was associated with the worst prognosis. The DAMPs subtyping system was successfully validated in the TCGA cohort. Furthermore, we systemically revealed the genomic alterations among the three DAMPs subtypes. The inflammatory DAMPs subtype was predicted to have the highest response rate to immunotherapy, suggesting that the constructed DAMPs clustering had potential for immunotherapy efficacy prediction.ConclusionWe established a novel ICD-associated DAMPs subtyping system in TNBC, and DAMPs expression might be a valuable biomarker for immunotherapy strategies. Our work could be helpful to the development of new immunomodulators and may contribute to the development of precision immunotherapy for TNBC.

Integrated Analysis of Genes Associated With Immune Microenvironment and Distant Metastasis in Uveal Melanoma.

Inflammatory infiltration plays an essential role in the progression of tumor malignancy. The aim of this study was to identify genes associated with inflammatory microenvironment and clinical traits for survival prediction of uveal melanoma (UVM) patients. The datasets and clinical characteristics of UVM were obtained from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. We divided the UVM patients into low and high immune cell infiltration groups, identified differentially expressed genes (DEGs), constructed weighted gene co-expression network, and established prognostic prediction model and nomogram for UVM. Our analysis showed that DEGs were enriched in cytokine signaling in immune system, positive regulation of immune response and adaptive immune system. A total of fifteen candidate genes were extracted from DEGs and genes that were positively associated with tumor metastasis. Subsequently, five prognostic genes were selected to construct the final prognostic prediction model, including two up-regulated genes LHFPL3 antisense RNA 1 (LHFPL3-AS1) and LYN proto-oncogene (LYN), and three down-regulated genes SLCO4A1 antisense RNA 1 (SLCO4A1-AS1), Zinc-α2-glycoprotein 1 (AZGP1) and Deleted in Liver Cancer-1 (DLC1) in the high risk group. The model showed an Area Under Curve (AUC) value of 0.877. Our analysis highlighted the importance of immune-related genes in the progression of UVM and also provided potential targets for the immunotherapy of UVM.

Network pharmacology and molecular docking analysis on molecular targets and mechanism prediction of Huanglian Jiedu Decoction in the treatment of COVID-19

ObjectiveTo investigate and predict the molecular targets and mechanism of Huanglian Jiedu Decoction (黄连解毒汤, HLJDD) in the treatment of Corona Virus Disease 2019 (COVID-19) through network pharmacology and molecular docking analysis. MethodsThe chemical constituents and action targets of HLJDD were retrieved on Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP), SymMap v2, Encyclopedia of Traditional Chinese Medicine (ETCM), a High-throughput Experiment- and Reference-guided Database of Traditional Chinese Medicine (HERB), and Traditional Chinese Medicine Integrated Database (TCMID). UniProt and GeneCards were used to query the target genes that corresponding to the active compounds, and then a compound-target network was constructed using Cytoscape 3.7.2. Gene Ontology (GO) database was used to annotate GO functions. Kyoto Encyclopedia of Genes and Genomes (KEGG) was used to predict the possible mechanisms of active compounds. The Database for Annotation, Visualization and Integrated Discovery (DAVID) was used to analysis the tissue enrichment. The main active compounds in HLJDD are molecularly docked with their corresponding related targets. ResultsSeventy-six compounds were screened and 458 corresponding targets in the network were obtained. Gene annotation showed that the targets were involved mainly in 1953 biological processes. 884 signaling pathways was enriched, involving signaling by interleukins, cytokine signaling in immune system, generic transcription pathway, and RNA polymerase II transcription. The targets mainly distributed in the lung, liver, and placenta, involving a variety of immune cells, such as T cells and B cells. The molecular docking results showed that core compounds such as wogonin, berberine, and baicalein had high affinity with tumor necrosis factor (TNF), insulin (INS), and tumor protein 53 (TP53). ConclusionThe active compounds in HLJDD may have a therapeutic effect on COVID-19 through regulating multiple signal pathways by targeting genes such as vascular endothelial growth factor A (VEGFA), INS, interleukin-6 (IL-6), TNF, caspase-3 , TP53, and mitogen-activated protein kinase 3 (MAPK3).

Altered TGFB1 regulated pathways promote accelerated tendon healing in the superhealer MRL/MpJ mouse

To better understand the molecular mechanisms of tendon healing, we investigated the Murphy Roth’s Large (MRL) mouse, which is considered a model of mammalian tissue regeneration. We show that compared to C57Bl/6J (C57) mice, injured MRL tendons have reduced fibrotic adhesions and cellular proliferation, with accelerated improvements in biomechanical properties. RNA-seq analysis revealed that differentially expressed genes in the C57 healing tendon at 7 days post injury were functionally linked to fibrosis, immune system signaling and extracellular matrix (ECM) organization, while the differentially expressed genes in the MRL injured tendon were dominated by cell cycle pathways. These gene expression changes were associated with increased α-SMA+ myofibroblast and F4/80+ macrophage activation and abundant BCL-2 expression in the C57 injured tendons. Transcriptional analysis of upstream regulators using Ingenuity Pathway Analysis showed positive enrichment of TGFB1 in both C57 and MRL healing tendons, but with different downstream transcriptional effects. MRL tendons exhibited of cell cycle regulatory genes, with negative enrichment of the cell senescence-related regulators, compared to the positively-enriched inflammatory and fibrotic (ECM organization) pathways in the C57 tendons. Serum cytokine analysis revealed decreased levels of circulating senescence-associated circulatory proteins in response to injury in the MRL mice compared to the C57 mice. These data collectively demonstrate altered TGFB1 regulated inflammatory, fibrosis, and cell cycle pathways in flexor tendon repair in MRL mice, and could give cues to improved tendon healing.

Abnormal RasGRP1 Expression in the Post-Mortem Brain and Blood Serum of Schizophrenia Patients.

Schizophrenia (SCZ) is a polygenic severe mental illness. Genome-wide association studies (GWAS) have detected genomic variants associated with this psychiatric disorder and pathway analyses have indicated immune system and dopamine signaling as core components of risk in dorsolateral-prefrontal cortex (DLPFC) and hippocampus, but the mechanistic links remain unknown. The RasGRP1 gene, encoding for a guanine nucleotide exchange factor, is implicated in dopamine signaling and immune response. RasGRP1 has been identified as a candidate risk gene for SCZ and autoimmune disease, therefore representing a possible point of convergence between mechanisms involving the nervous and the immune system. Here, we investigated RasGRP1 mRNA and protein expression in post-mortem DLPFC and hippocampus of SCZ patients and healthy controls, along with RasGRP1 protein content in the serum of an independent cohort of SCZ patients and control subjects. Differences in RasGRP1 expression between SCZ patients and controls were detected both in DLPFC and peripheral blood of samples analyzed. Our results indicate RasGRP1 may mediate risk for SCZ by involving DLPFC and peripheral blood, thus encouraging further studies to explore its possible role as a biomarker of the disease and/or a target for new medication.

Reinfection of Transplanted Livers in HCV- and HCV/HIV-Infected Patients Is Characterized by a Different MicroRNA Expression Profile.

Background: After liver transplantation, HCV/HIV co-infected patients present, compared to the HCV mono-infected ones, increased HCV viral load, rapid progression to liver fibrosis and higher mortality. Liver biopsies (LB), obtained routinely 6 months after transplantation, represent a unique model to assess the early events related to graft re-infection. Here, we used miRNA sequencing of LB obtained from both HCV-and HCV/HIV-infected recipients, to identify transcriptional profiles able to explain the more severe outcome of these latter. Methods: miRNAs of 3 healthy livers, 3 HCV-LB and 3 HCV/HIV-LB were sequenced by Illumina HiSeq2500 platform. The DIANA-miRPath v3.0 webserver and DIANA-microT-CDS algorithm (v5.0) were used to characterize the functions of differentially expressed (DE-) miRNAs, querying the KEGG and Gene Ontology-Biological Process databases. Results: LB obtained from infected patients were characterized, with respect to controls, by a miRNA profile related to viral infection, immune system signaling and DNA damage in HCV-induced carcinogenesis. Instead, HCV-LB and HCV/HIV-LB differed in the expression of miRNAs involved in immunological and apoptotic processes and in extracellular matrix remodeling. Conclusions: liver reinfection processes are associated with early miRNA changes. Further studies are necessary to establish their prognostic role and possible actionability.

Developmental Origins of Metaflammation; A Bridge to the Future Between the DOHaD Theory and Evolutionary Biology.

Metabolic syndrome refers to obesity-associated metabolic disorders that increase the risk of type 2 diabetes, coronary diseases, stroke, and other disabilities. Environmental imbalance during the early developmental period affects health and increases susceptibility to non-communicable diseases, including metabolic syndrome, in later life; therefore, the Developmental Origins of Health and Disease (DOHaD) theory was established. According to the DOHaD theory, the hypothesis of the energy-saving ‘Thrifty Phenotype’ in undernourished fetuses is one of the well-accepted schemes as a risk of developing metabolic syndrome. This phenotype is evolutionarily advantageous for survival of the fittest in a hangry environment after birth, a strong selection pressure, but increases the risk of developing metabolic syndrome under an obesogenic diet according to the ‘Mismatch’ hypothesis. Increasing evidences support that chronic inflammation pathophysiologically connects obesity to metabolic disorders in metabolic syndrome, leading to the concept of ‘Metaflammation’. ‘Metaflammation’ in humans is proposed to originate from the evolutionary conservation of crosstalk between immune and metabolic pathways; however, few studies have investigated the contribution of evolutionary maladaptation to the pathophysiology of ‘Metaflammation’. Therefore, it is promising to investigate ‘Metaflammation’ from the viewpoint of selective advantages and its ‘Mismatch’ to an unexpected environment in contemporary lifestyles, in consideration of the principal concept of evolutionarily conserved nutrient sensing and immune signaling systems.

Gene Expression Profile Analyses of the Skin Response of Balb/c-Nu Mice Model Injected by Staphylococcus aureus.

BackgroundPathogenesis and persistence of many skin diseases are related to Staphylococcus aureus (S. aureus) colonization. S. aureus infection can cause varying degrees of changes in cell gene expression, resulting in complex changes in cell phenotype and finally changes in cell life activities.Materials and MethodsThe transcriptomes of healthy and Staphylococcus aureus (S. aureus)-infected murine skin tissues were analyzed. We identified 638 differentially expressed genes (DEGs) in the infected tissues compared to the control samples, of which 324 were upregulated and 314 were downregulated, following the criteria of P < 0.01 and |log2FC| > 3. The DEGs were functionally annotated by Gene Ontology (GO), KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway and the protein–protein interaction (PPI) network analyses.ResultsThe upregulated DEGs were mainly enriched in GO terms, such as response to stimulus, immune system process and signal transduction, as well as in the complement and coagulation cascade pathway. Thus, S. aureus infection likely activates these pathways to limit the influx of neutrophils and prevent skin damage. Four clusters were identified in the PPI network, and the major hubs were mainly related to cell cycle and proliferation, and mostly downregulated. The expression levels of Nox4, Mmrn1, Mcm5, Msx1 and Fgf5 mRNAs were validated by qRT-PCR and found to be consistent with the RNA-Seq data, confirming a strong correlation between the two approaches.ConclusionThe identified genes and pathways are potential drug targets for treating skin inflammation caused by S. aureus and should be investigated further.

Analysis of transcript-wide profile regulated by microsatellite instability of colorectal cancer.

BackgroundMicrosatellite instability-high (MSI-H) is a form of genomic instability present in 15% of colorectal cancer (CRC) cases. Several differential gene analyses have been conducted on CRC; however, none have specifically explored the differentially expressed genes in MSI-H CRC. Research on the different gene expressions between MSI-H CRC and microsatellite stable (MSS) CRC, and their different patterns of metastasis will provide invaluable insights for diagnosis, prognosis, and treatment.MethodsIn this study, the differential expression of 46,602 genes were analyzed across 613 different tissue samples from The Cancer Genome Atlas (TCGA)-colon adenocarcinoma (COAD) and TCGA-rectum adenocarcinoma (READ) as part of a gene association analysis. R package TCGAbiolinks (version 2.18.0) was used to download the data set, and DESeq2 (version 1.30.1) was used for the differential gene analysis. The resulting genes were then analyzed for shared pathways with R package clusterProfiler (version 3.0.4).ResultsA total of 237 significantly differentially expressed genes (Padj<0.05) were found between MSI-H and MSS CRC. Differentially expressed genes include insulin like growth factor 2 (IGF2) and fibroblast growth factor 3 (FGF3), and the enriched pathways mostly involve hearing, digestive regulation, and neurogenesis.463 differentially expressed genes were found between metastatic and non-metastatic CRC. Notably differentially expressed genes in metastatic CRC include DEAD-box helicase 53 (DDX53) and adiponectin, C1Q and collagen domain containing (ADIPOQ), and enriched pathways include the immune system, cell adhesion, and cell signaling. For MSI-H CRC, a total of 34 genes were significantly differently expressed between metastatic and non-metastatic CRC. These include notum, palmitoleoyl-protein carboxylesterase (NOTUM), serpin family B member 2 (SERPINB2), and several keratin (KRT) genes, and the pathway analysis showed the major enrichment of the hormonal and secretion and regulation pathways. Of the differentially expressed genes in metastatic CRC, 25 were immunity related and include fatty acid binding protein 4 (FABP4), and the pathway analysis showed the enrichment of humoral immunity and lymphocyte regulation.ConclusionsOf the biologically plausible differentially expressed genes, the most notable were NOTUM, KRT6A, KRT14, SERPINB2, and serum amyloid A1 (SAA1). NOTUM, KRT6A, and KRT14 are active in the Wnt pathway. All five are also involved in various inflammation pathways.

Spermine Regulates Immune and Signal Transduction Dysfunction in Diabetic Cardiomyopathy.

BackgroundDiabetic cardiomyopathy (DCM) is a specific form of cardiomyopathy that is independent of coronary artery disease and hypertension. Exploring the transcriptomics of DCM is of great significance for understanding the biology of the disease and for guiding new therapeutic targets for the potential therapeutic effect of spermine (SPM).Methods and ResultsBy using a mouse DCM model, we analyzed the transcriptome of the myocardium, before/after treatment with SPM. Using RNA sequencing (RNA-seq), we identified 1,318 differentially expressed genes (DEGs), with 636 being upregulated and 682 being downregulated in DCM compared to control check (CK). We then identified 1,393 DEGs, with 887 being upregulated and 506 being downregulated in SPM compared to DCM. Kyoto Encyclopedia of Genes And Genomes (KEGG) analysis demonstrated that the DEGs were significantly enriched in the immune system and signal transduction-related pathways. UpSet Venn analysis showed that 174 DEGs in DCM could be reversed by SPM, with 45 candidates related to immune system and related signal transduction pathways. Trend analysis demonstrated the dynamic changes in gene levels in DCM and SPM treatment, shown as 49 immune and signal transduction-related candidates were significantly enriched in some classical pathways, such as complement and coagulation cascades and phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)-protein kinase B (Akt) signaling pathway. To further reveal the protective mechanism of SPM to DCM, we predicted 14 overlapped transcription factors (TFs) and their co-factors involved in gene transcription regulation and showed gene interaction with Cytoscape.ConclusionThe biomarkers and canonical pathways identified in this study may hold the key to understanding the mechanisms of DCM pathobiology and providing new targets for the therapeutic effect of SPM against DCM by targeting abnormal immune response and signal transduction.

Insights Into the Prognostic Value and Immunological Role of NAAA in Pan-Cancer.

N-Acylethanolamine Acid Amidase (NAAA) is an N-terminal cysteine hydrolase and plays a vital physiological role in inflammatory response. However, the roles of NAAA in tumor immunity are still unclear. By using a series of bioinformatics approaches, we study combined data from different databases, including the Cancer Genome Atlas, the Cancer Cell Line Encyclopedia, Genotype Tissue-Expression, cBioPortal, Human Protein Atlas, TIMER, and ImmuCellAI to investigate the role of NAAA expression in prognosis and tumor immunity response. We would like to reveal the potential correlations between NAAA expression and gene alterations, tumor mutational burden (TMB), microsatellite instability (MSI), DNA methylation, tumor microenvironment (TME), immune infiltration levels, and various immune-related genes across different cancers. The results show that NAAA displayed abnormal expression within most malignant tumors, and overexpression of NAAA was associated with the poor prognosis of tumor patients. Through gene set enrichment analysis (GSEA), we found that NAAA was significantly associated with cell cycle and immune regulation-related signaling pathways, such as in innate immune system, adaptive immune system, neutrophil degranulation, and Toll-like receptor signaling pathways (TLRs). Further, the expression of NAAA was also confirmed to be correlated with tumor microenvironment and diverse infiltration of immune cells, especially tumor-associated macrophage (TAM). In addition to this, we found that NAAA is co-expressed with genes encoding major histocompatibility complex (MHC), immune activation, immune suppression, chemokine, and chemokine receptors. Meanwhile, we demonstrate that NAAA expression was correlated with TMB in 4 cancers and with MSI in 10 cancers. Our study reveals that NAAA plays an important role in tumorigenesis and cancer immunity, which may be used to function as a prognostic biomarker and potential target for cancer immunotherapy.

CSF proteomic signature predicts progression to Alzheimer's disease dementia.

IntroductionIndividuals in the Alzheimer's disease (AD) continuum with mild cognitive impairment (prodromal AD) are at increased risk to develop dementia. Still, underlying pathophysiological processes remain unclear. We studied whether cerebrospinal fluid (CSF) proteome changes are related to time to clinical progression in prodromal AD.MethodsWe measured 671 CSF proteins in 49 prodromal AD individuals (67±7 years old, 22 [45%] female) from the Amsterdam Dementia Cohort. Associations of protein levels with time to dementia onset were tested with Cox regression models, followed by biological pathway enrichment analysis.ResultsEighteen (36%) individuals developed dementia during follow‐up. In total, 128 (98%) proteins were associated with a 1.4‐ to 17‐fold increased risk of progression to dementia (all P < .05). These proteins showed enrichment for immune system processes, signal transduction, neuronal death, and neurodevelopmental biology.DiscussionCSF proteome changes related to rate of progression to dementia can be detected in prodromal AD, providing more insight into processes involved in early AD pathophysiology.

Adaptive Evolution in TRIF Leads to Discordance between Human and Mouse Innate Immune Signaling.

The TIR domain-containing adapter inducing IFN-β (TRIF) protein is an innate immune system protein that mediates the MyD88-independent toll-like receptor response pathway in mice and humans. Previously, we identified positive selection at seven distinct residues in mouse TRIF (mTRIF), as compared with human and other mammalian orthologs, thus predicting protein functional shift in mTRIF. We reconstructed TRIF for the most recent common ancestor of mouse and human, and mutated this at the seven sites to their extant mouse/human states. We overexpressed these TRIF mutants in immortalized human and mouse cell lines and monitored TRIF-dependent cytokine production and gene expression induction. We show that optimal TRIF function in human and mouse is dependent on the identity of the positively selected sites. These data provide us with molecular data relating observed differences in response between mouse and human MyD88-independent signaling in the innate immune system with protein functional change.

A shared oligodendrocyte activation state associated with neuroinflammation and neurodegeneration.

Alzheimer's disease (AD) is a devastating neurodegenerative disease. Despite intensive research, all current therapeutic attempts have failed, highlighting the need for new therapeutic approaches. While most research traditionally attributed cognitive impairment to neuronal damage, recent studies have highlighted the role of non-neuronal cells, mainly the brain innate-immune cells, the microglia. However, the contribution of non-immune glial cells remains elusive.Oligodendrocytes are the central nervous system myelin-forming cells and are crucial for proper neuronal signaling and brain function. However, little is known about their fate in AD. In our study, we aimed to reveal cellular heterogeneity among non-immune glia, and particularly oligodendrocytes, in AD. To this end, we used the 5xFAD model of AD and performed single cell RNA-sequencing, bulk RNA-sequencing, computational meta-analysis and immunofluorescence stainings in mouse and human AD brain. We found that oligodendrocytes are the most affected cell type and unveiled a novel oligodendrocyte cell-state, which we termed 'Disease-associated OLigodendrocytes' (DOLs). DOLs were found in the AD mouse brains but not in the wild-type (WT), spatially associated with amyloid-beta plaques and increased with disease progression. DOL signature points at possible interactions with the immune system and immune-related signaling, plaque propagation, and blood-brain-barrier interference. Meta-analysis across other neuroinflammatory and neurodegenerative conditions revealed a conserved oligodendrocyte response similar to DOLs. Bulk RNA-sequencing of oligodendrocytes following different stimulations revealed partial similarity between DOL signature and oligodendrocyte response to specific inflammatory cues. Lastly, we showed that DOLs are present also in human AD brains but not in healthy controls. Overall, this study demonstrates that oligodendrocytes have a common response to neuroinflammation and neurodegeneration, which is recapitulated in humans, and can serve as a potential therapeutic target in multiple pathologies.

Exercise Cuts Both Ways with ROS in Remodifying Innate and Adaptive Responses: Rewiring the Redox Mechanism of the Immune System during Exercise.

Nearly all cellular functions depend on redox reactions, including those of immune cells. However, how redox reactions are rearranged to induce an immune response to the entry of pathogens into the host is a complex process. Understanding this scenario will facilitate identification of the roles of specific types of reactive oxygen species (ROS) in the immune system. Although the detrimental effect of ROS could support the innate immune system, the adaptive immune system also requires a low level of ROS in order to stimulate various molecular functions. The requirements and functions of ROS vary in different cells, including immune cells. Thus, it is difficult to understand the specific ROS types and their targeting functions. Incomplete transfer of electrons to a specific target, along with failure of the antioxidant response, could result in oxidative-damage-related diseases, and oxidative damage is a common phenomenon in most immune disorders. Exercise is a noninvasive means of regulating ROS levels and antioxidant responses. Several studies have shown that exercise alone boosts immune functions independent of redox reactions. Here, we summarize how ROS target various signaling pathways of the immune system and its functions, along with the possible role of exercise in interfering with immune system signaling.

Bcl2 Inhibitor and DNA Hypomethylating Agent Prolong Survival in Patient-Derived Xenograft Model of Down Syndrome Myeloid Leukemia By Synergistic Downregulation of Cytokine Signaling

Background:Down syndrome is known for its leukemia predisposition effects. Children with Down syndrome myeloid leukemia who fail chemotherapy, have a poor outcome. No targeted therapies are available for this population. We have generated and extensively characterized several patient-derived xenograft (PDX) models of Down syndrome AML (Barwe et al., 134:2683, Blood, 2019). We evaluated the efficacy of a combination of DNA hypomethylating agent, azacitidine and Bcl2 inhibitor, venetoclax in PDX model of Down syndrome AML. Although this drug combination is used in the clinic for the treatment of adult AML, their combinatorial mechanism of action is not well known.Methods:NTPL-386 (3 x 10 6 cells) were injected intravenously in NSG-SGM3 mice. Disease progression was monitored by determination of the percentage of human chimerism in peripheral blood by flow cytometry. Mice were randomly assigned to treatment groups (n=5) on day 13 when human CD45+ cells were detectable in blood. Azacitidine (2.5 mg/Kg) was administered intraperitoneally on days 13-19 and venetoclax (100 mg/Kg) was delivered orally on days 13-40 (Fig. 1A). Mice were monitored daily for pre-determined experimental endpoints and were euthanized when any of the endpoints were attained. Kaplan-Meier survival plots were generated. AML cells were harvested from treated mice and lysed, RNA was isolated and sequenced. Pathway analysis was performed to identify the mechanism of action of these two drugs in combination.Results:Azacitidine treatment for one week increased median survival by 8 days compared to untreated mice (Fig. 1B). Venetoclax treatment for 4 weeks was more effective than azacitidine and extended survival by 27 days (P<0.005, compared to untreated). We observed that the combination of venetoclax and azacitidine was much more efficient and prolonged survival by 39 days in this PDX model of refractory Down syndrome AML (P<0.005 and P<0.05 compared to single agent azacitidine or venetoclax respectively). This combination performed better than chemotherapy consisting of cytarabine and daunorubicin, which showed a 11-day improvement in median survival compared to untreated in our previous study (Barwe et al., 134:2683, Blood, 2019).To understand the mechanism of synergism between these two drugs, we conducted transcriptome analysis on cells harvested from mice (n=3 per group) receiving venetoclax and azacitidine, alone or in combination. The log fold changes for each treatment with respect to untreated were calculated and filtered based on FDR>0.05. The genes that were differentially regulated in the combination treatment (Fig. 1C, blue circle in the Venn diagram) were subjected to ToppGene analysis. A heatmap of the differentially regulated genes shows clustering of the replicates from individual mice (Fig. 1D). ‘Hematopoietic cell lineage’ and ‘cytokine signaling in immune system’ were the top modulated pathways in the combination treatment. A heatmap of the logFC of the differentially regulated genes from this pathway showed the modulation of these genes in the combination in comparison with individual drug treatment (Fig. 1E). The differentially regulated genes in the combination treatment that showed high variance from the range defined by individual drug treatment belonged to one of three categories - cell surface proteins, cytokines, and stem cell markers. These data indicate that the synergistic downregulation of cytokine signaling is likely responsible for the combinatorial effect of venetoclax and azacitidine.Conclusion:The combination of venetoclax and azacitidine was effective in prolonging survival in a highly refractory Down syndrome AML PDX model (NTPL-386) generated in the laboratory. The top genes differentially regulated by the combination treatment which varied the most in magnitude from the individual drug treatment identified genes that are likely to contribute to the synergism between the two drugs. [Display omitted] DisclosuresBarwe: Prelude Therapeutics: Research Funding. Gopalakrishnapillai: Geron: Research Funding.

Molecular cloning and functional analysis of Macaca mulatta STING

Stimulator of interferon gene (STING), an adaptor molecule in the immune system, is involved in mediating the response to viral and bacterial infections, anti-tumor immunity, autoimmune diseases, and lipid metabolism. There have been reports on the cloning and function of STING in humans, pigs, chickens, and cats; however, STING has not been characterized in non-human primates or monkeys to date. Therefore, in this study, the rhesus macaque (Macaca mulata) STING gene was cloned, and we performed preliminary functional tests to examine its role in the interferon (IFN) pathway. The M. mulatta STING complementary DNA was 1140 bp in length and encoded 380 amino acid residues. Phylogenetic analysis showed that Homo sapiens and M. mulatta STING are closely related and clustered on the same branch. M. mulatta STING was confirmed to increase the promoter activities of IFN-β, nuclear factor-κB, and interferon-sensitive response element, and STING overexpression increased the mRNA levels of IFN-α, IFN-β, and interferon regulatory factor 3. Infection of Marc-145 cells with porcine reproductive and respiratory syndrome virus activated STING, and its expression increased along with increases in viral multiplicity of infection titer and time. Moreover, STING expression was time- and dose-dependently up-regulated by poly (I:C) and poly (dA:dT) treatments in Marc-145 cells. In summary, these results highlight STING as a vital immune system signal protein in the IFN pathway. This study provides a basis for understanding the immune characteristics of M. mulatta, and may have important implications for both monkey and human diseases.