scholarly journals A conserved long noncoding RNA, GAPLINC, modulates the immune response during endotoxic shock

2021 ◽  
Vol 118 (7) ◽  
pp. e2016648118
Author(s):  
Apple Cortez Vollmers ◽  
Sergio Covarrubias ◽  
Daisy Kuang ◽  
Aaron Shulkin ◽  
Justin Iwuagwu ◽  
...  
Keyword(s):  
Immune Response ◽  
Knockout Mice ◽  
Noncoding Rna ◽  
Target Genes ◽  
Blood Clot ◽  
Multiorgan Failure ◽  
Endotoxic Shock ◽  
Negative Regulator ◽  
Inflammatory Genes ◽  
Lps Challenge

Recent studies have identified thousands of long noncoding RNAs (lncRNAs) in mammalian genomes that regulate gene expression in different biological processes. Although lncRNAs have been identified in a variety of immune cells and implicated in immune response, the biological function and mechanism of the majority remain unexplored, especially in sepsis. Here, we identify a role for a lncRNA—gastric adenocarcinoma predictive long intergenic noncoding RNA (GAPLINC)—previously characterized for its role in cancer, now in the context of innate immunity, macrophages, and LPS-induced endotoxic shock. Transcriptome analysis of macrophages from humans and mice reveals that GAPLINC is a conserved lncRNA that is highly expressed following macrophage differentiation. Upon inflammatory activation, GAPLINC is rapidly down-regulated. Macrophages depleted of GAPLINC display enhanced expression of inflammatory genes at baseline, while overexpression of GAPLINC suppresses this response. Consistent with GAPLINC-depleted cells, Gaplinc knockout mice display enhanced basal levels of inflammatory genes and show resistance to LPS-induced endotoxic shock. Mechanistically, survival is linked to increased levels of nuclear NF-κB in Gaplinc knockout mice that drives basal expression of target genes typically only activated following inflammatory stimulation. We show that this activation of immune response genes prior to LPS challenge leads to decreased blood clot formation, which protects Gaplinc knockout mice from multiorgan failure and death. Together, our results identify a previously unknown function for GAPLINC as a negative regulator of inflammation and uncover a key role for this lncRNA in modulating endotoxic shock.

scholarly journals Long non-coding RNA profiling in LPS-induced intestinal inflammation model: New insight into pathogenesis

2019 ◽  
Vol 25 (8) ◽  
pp. 491-502
Author(s):  
Ling Guo ◽  
Linna Li ◽  
Yang Zhang ◽  
Shulin Fu ◽  
Jing Zhang ◽  
...  
Keyword(s):  
Immune Response ◽  
Target Genes ◽  
Intestinal Inflammation ◽  
Ileal Mucosa ◽  
Rna Profiling ◽  
Lps Challenge ◽  
Non Coding Rna ◽  
Inflammatory Immune Response ◽  
Novel Target ◽  
Long Non Coding Rna

LPS can induce an inflammatory immune response in the intestine, and long non-coding RNA (lncRNA) is involved in the process of inflammatory disease. However, the biological role of lncRNA in the intestinal inflammation of piglets remains unclear. In this study, the lncRNA expression profile of the ileal mucosa of piglets challenged by LPS was analysed using lncRNA sequencing. In total, 112 novel lncRNAs were predicted, of which 58 were up-regulated and 54 down-regulated following LPS challenge. Expression of 15 selected lncRNAs was validated by quantitative PCR. We further investigated the target genes of lncRNA that were enriched in the signalling pathways involved in the inflammatory immune response by utilising Gene Ontology and Kyoto Encyclopaedia of Genes and Genomes analysis, with cell adhesion molecules and mTOR signalling pathway identified. In addition, the co-expression networks between the differentially expressed lncRNAs and the target mRNAs were constructed, with seven core lncRNAs identified, which also demonstrated that the relationship between lncRNAs and the target genes was highly correlated. Our study offers important information about the lncRNAs of the mucosal immune system in piglets and provides new insights into the inflammatory mechanism of LPS challenge, which might serve as a novel target to control intestinal inflammation.

scholarly journals Long Noncoding RNA NTT Context-Dependently Regulates MYB by Interacting With Activated Complex in Hepatocellular Carcinoma Cells

2021 ◽  
Vol 11 ◽  
Author(s):  
Ya-Sian Chang ◽  
Ya-Ting Lee ◽  
Ju-Chen Yen ◽  
Yuli C. Chang ◽  
Li-Li Lin ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Long Noncoding Rna ◽  
Noncoding Rna ◽  
Target Genes ◽  
Metabolic Diseases ◽  
Cellular Migration ◽  
Negative Regulator ◽  
Dependent Manner ◽  
Colon Cancers ◽  
Activated Complex

BackgroundLong noncoding RNA (lncRNA) mediates the pathogenesis of various diseases, including cancer and cardiovascular, infectious, and metabolic diseases. This study examined the role of lncRNA NTT in the development and progression of cancer.MethodsThe expression of NTT was determined using tissues containing complementary DNA (cDNA) from patients with liver, lung, kidney, oral, and colon cancers. The expression of cis-acting genes adjacent to the NTT locus (CTGF, STX7, MYB, BCLAF1, IFNGR1, TNFAIP3, and HIVEP2) was also assessed. We used knockdown and chromatin immunoprecipitation (ChIP) assays to identify the cis-acting genes that interact with NTT.ResultsNTT was most significantly downregulated in hepatocellular carcinoma (HCC), while a higher NTT level correlated with a shorter survival time of patients with HCC. Multivariate analysis indicated NTT was not an independent predictor for overall survival. MYB was significantly upregulated, and its increased expression was associated with dismal survival in HCC patients, similar to the results for NTT. NTT knockdown significantly decreased cellular migration. ChIP of HCC cell lines revealed that NTT is regulated by the transcription factor ATF3 and binds to the MYB promoter via the activated complex. Additionally, when NTT was knocked down, the expression of MYB target genes such as Bcl-xL, cyclinD1, and VEGF was also downregulated. NTT could play a positive or negative regulator for MYB with a context-dependent manner in both HCC tissues and animal model.ConclusionOur study suggests that NTT plays a key role in HCC progression via MYB-regulated target genes and may serve as a novel therapeutic target.

scholarly journals SPOP Promotes Ubiquitination and Degradation of MyD88 to Suppress the Innate Immune Response

2019 ◽  
Author(s):  
Qinghe Li ◽  
Fei Wang ◽  
Qiao Wang ◽  
Maiqing Zheng ◽  
Ranran Liu ◽  
...  
Keyword(s):  
Immune Response ◽  
Autoimmune Diseases ◽  
Salmonella Typhimurium ◽  
Innate Immune Response ◽  
Innate Immune ◽  
Negative Regulator ◽  
Microbial Pathogens ◽  
Genetic Ablation ◽  
Susceptibility To Infection ◽  
Lps Challenge

AbstractAs a canonical adaptor for Toll-like receptor (TLR) family, MyD88 has crucial roles in host defence against infection of microbial pathogens and its dysregulation might induce autoimmune diseases. Here we demonstrate that the Cullin 3-based ubiquitin ligase adaptor SPOP recognizes the intermediate domain and degrades chMyD88 through the proteasome pathway. Knockdown or genetic ablation of chSPOP leads to aberrant elevation of the chMyD88 protein. Consequently, ChSPOP negatively regulates the activity of NF-κB pathway and thus the production of IL-1β and IL-8 upon LPS challenge. Furthermore, SPOP deficiency mice are more susceptible to infection of Salmonella typhimurium. Collectively, these findings demonstrate chMyD88 as a bona fide substrate of chSPOP and uncover a mechanism by which chSPOP suppresses the innate immune signaling.Author SummaryMyD88 is a central adaptor mediating the initiate of innate immune response and production of proinflammatory cytokines that restrain pathogens and activate adaptive immunity. Although MyD88 is crucial for the host to prevent pathogenic infection, misregulation of MyD88 abundance might lead to autoimmune diseases. Thus, degradation of MyD88 is a canonical mechanism to terminate cytokines production. Here we characterized a novel E3 ligase SPOP that target MyD88 for degradation. SPOP attenuated IL1β and IL8 production through K48-linked polyubiquitination and degradation of MyD88 and thus impaired immune responses. SPOP deficient mice show more susceptibility to infection by Salmonella typhimurium. These findings demonstrate that SPOP is a negative regulator of MyD88-dependent pathway activation triggered by LPS and Salmonella typhimurium, which helps the host to maintain immune homeostasis.

scholarly journals Susceptibility rhythm to bacterial endotoxin in myeloid clock-knockout mice

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Veronika Lang ◽  
Sebastian Ferencik ◽  
Bharath Ananthasubramaniam ◽  
Achim Kramer ◽  
Bert Maier
Keyword(s):  
Knockout Mice ◽  
Endotoxic Shock ◽  
Time Of Day ◽  
Conditional Knockout ◽  
Constant Darkness ◽  
Immune Functions ◽  
Lps Challenge ◽  
Circadian Time ◽  
Tnf Α ◽  
Circadian Physiology

Local circadian clocks are active in most cells of our body. However, their impact on circadian physiology is still under debate. Mortality by endotoxic (LPS) shock is highly time-of-day dependent and local circadian immune function such as the cytokine burst after LPS challenge has been assumed to be causal for the large differences in survival. Here, we investigate the roles of light and myeloid clocks on mortality by endotoxic shock. Strikingly, mice in constant darkness (DD) show a three-fold increased susceptibility to LPS as compared to mice in light-dark conditions. Mortality by endotoxic shock as a function of circadian time is independent of light-dark cycles as well as myeloid CLOCK or BMAL1 as demonstrated in conditional knockout mice. Unexpectedly, despite the lack of a myeloid clock these mice still show rhythmic patterns of pro- and anti-inflammatory cytokines such as TNF,α MCP-1, IL-18 and IL-10 in peripheral blood as well as time-of-day and site dependent traffc of myeloid cells. We speculate that systemic time-cues are sufficient to orchestrate innate immune response to LPS by driving immune functions such as cell traffcking and cytokine expression.

scholarly journals Long Noncoding RNA Lnc-MxA Inhibits Beta Interferon Transcription by Forming RNA-DNA Triplexes at Its Promoter

2019 ◽  
Vol 93 (21) ◽  
Author(s):  
Xinda Li ◽  
Guijie Guo ◽  
Min Lu ◽  
Wenjia Chai ◽  
Yucen Li ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Noncoding Rna ◽  
Influenza A ◽  
Sendai Virus ◽  
Negative Regulator ◽  
Host Cells ◽  
Luciferase Assay ◽  
Antiviral Immune Response ◽  
Beta Interferon

ABSTRACT Previously, we identified a set of long noncoding RNAs (lncRNAs) that were differentially expressed in influenza A virus (IAV)-infected cells. In this study, we focused on lnc-MxA, which is upregulated during IAV infection. We found that the overexpression of lnc-MxA facilitates the replication of IAV, while the knockdown of lnc-MxA inhibits viral replication. Further studies demonstrated that lnc-MxA is an interferon-stimulated gene. However, lnc-MxA inhibits the Sendai virus (SeV)- and IAV-induced activation of beta interferon (IFN-β). A luciferase assay indicated that lnc-MxA inhibits the activation of the IFN-β reporter upon stimulation with RIG-I, MAVS, TBK1, or active IRF3 (IRF3-5D). These data indicated that lnc-MxA negatively regulates the RIG-I-mediated antiviral immune response. A chromatin immunoprecipitation (ChIP) assay showed that the enrichment of IRF3 and p65 at the IFN-β promoter in lnc-MxA-overexpressing cells was significantly lower than that in control cells, indicating that lnc-MxA interfered with the binding of IRF3 and p65 to the IFN-β promoter. Chromatin isolation by RNA purification (ChIRP), triplex pulldown, and biolayer interferometry assays indicated that lnc-MxA can bind to the IFN-β promoter. Furthermore, an electrophoretic mobility shift assay (EMSA) showed that lnc-MxA can form complexes with the IFN-β promoter fragment. These results demonstrated that lnc-MxA can form a triplex with the IFN-β promoter to interfere with the activation of IFN-β transcription. Using a vesicular stomatitis virus (VSV) infection assay, we confirmed that lnc-MxA can repress the RIG-I-like receptor (RLR)-mediated antiviral immune response and influence the antiviral status of cells. In conclusion, we revealed that lnc-MxA is an interferon-stimulated gene (ISG) that negatively regulates the transcription of IFN-β by forming an RNA-DNA triplex. IMPORTANCE IAV can be recognized as a nonself molecular pattern by host immune systems and can cause immune responses. However, the intense immune response induced by influenza virus, known as a “cytokine storm,” can also cause widespread tissue damage (X. Z. J. Guo and P. G. Thomas, Semin Immunopathol 39:541–550, 2017, https://doi.org/10.1007/s00281-017-0636-y; S. Yokota, Nihon Rinsho 61:1953–1958, 2003; I. A. Clark, Immunol Cell Biol 85:271–273, 2007). Meanwhile, the detailed mechanisms involved in the balancing of immune responses in host cells are not well understood. Our studies reveal that, as an IFN-inducible gene, lnc-MxA functions as a negative regulator of the antiviral immune response. We uncovered the mechanism by which lnc-MxA inhibits the activation of IFN-β transcription. Our findings demonstrate that, as an ISG, lnc-MxA plays an important role in the negative-feedback loop involved in maintaining immune homeostasis.

Pleiotropic functions of TNF-α determine distinct IKKβ-dependent hepatocellular fates in response to LPS

2007 ◽  
Vol 292 (1) ◽  
pp. G242-G252 ◽  
Author(s):  
Rana Dajani ◽  
Salih Sanlioglu ◽  
Yulong Zhang ◽  
Qiang Li ◽  
Martha M. Monick ◽  
...  
Keyword(s):  
Knockout Mice ◽  
Viral Vectors ◽  
Endotoxic Shock ◽  
Lethal Dose ◽  
Dominant Negative ◽  
Endotoxin Challenge ◽  
Lps Challenge ◽  
Differential Outcomes ◽  
Tnf Α ◽  
Pleiotropic Functions

TNF-α influences morbidity and mortality during the course of endotoxemia. However, the complex pleiotropic functions of TNF-α remain poorly understood. We evaluated how hepatic induction of NF-κB and TNF-α influence survival and hepatocellular death in a lethal murine model of endotoxic shock. Using dominant-negative viral vectors to inhibit the IKK complex, we demonstrate through this study that the liver is a major source of TNF-α during the course of lethal endotoxemia and that IKKβ (but not IKKα) is predominantly responsible for activating NF-κB and TNF-α in the liver after LPS administration. Using TNF-α knockout mice and hepatic-specific inhibition of IKKβ, we demonstrate that the status of TNF-α and NF-κB balances necrotic and apoptotic fates of hepatocytes in the setting of endotoxemia. In the presence of TNF-α, inhibiting hepatic IKKβ resulted in increased survival, reduced serum proinflammatory cytokines, and reduced hepatocyte necrosis in response to a lethal dose of endotoxin. In contrast, inhibiting hepatic IKKβ in TNF-α knockout mice resulted in decreased survival and increased caspase 3-mediated hepatocyte apoptosis after endotoxin challenge, despite a reduced proinflammatory cytokine response. In the presence of TNF-α, NF-κB-dependent hepatocellular necrosis predominated, while in the absence of TNF-α, NF-κB primarily influenced apoptotic fate of hepatocytes. Changes in JNK phosphorylation after LPS challenge were also dynamically affected by both IKKβ and TNF-α; however, this pathway could not solely explain the differential outcomes in hepatocellular fates. In conclusion, our studies demonstrate that induction of NF-κB and TNF-α balances protective (antiapoptotic) and detrimental (proinflammatory) pathways to determine hepatocellular fates during endotoxemia.

scholarly journals Susceptibility rhythm to bacterial endotoxin in myeloid clock-knockout mice

2019 ◽  
Author(s):  
Veronika Lang ◽  
Sebastian Ferencik ◽  
Bharath Ananthasubramaniam ◽  
Achim Kramer ◽  
Bert Maier
Keyword(s):  
Knockout Mice ◽  
Endotoxic Shock ◽  
Time Of Day ◽  
Conditional Knockout ◽  
Constant Darkness ◽  
Cell Trafficking ◽  
Immune Functions ◽  
Lps Challenge ◽  
Circadian Time ◽  
Circadian Physiology

AbstractLocal circadian clocks are active in most cells of our body. However, their impact on circadian physiology is still under debate. Mortality by endotoxic (LPS) shock is highly time-of-day dependent and local circadian immune function such as the cytokine burst after LPS challenge has been assumed to be causal for the large differences in survival. Here, we investigate the roles of light and myeloid clocks on mortality by endotoxic shock. Strikingly, mice in constant darkness (DD) show a three-fold increased susceptibility to LPS as compared to mice in light-dark conditions. Mortality by endotoxic shock as a function of circadian time is independent of light-dark cycles as well as myeloid CLOCK or BMAL1 as demonstrated in conditional knockout mice. Unexpectedly, despite the lack of a myeloid clock these mice still show rhythmic patterns of pro- and anti-inflammatory cytokines such as TNFα, MCP-1, IL-18 and IL-10 in peripheral blood as well as time-of-day and site dependent traffic of myeloid cells. We speculate that systemic time-cues are sufficient to orchestrate innate immune response to LPS by driving immune functions such as cell trafficking and cytokine expression.

The SNPs within 3'UTR of miRNA Target Genes Related to Multiple Sclerosis: A Computational Prediction

2020 ◽  
Vol 17 (2) ◽  
pp. 133-147
Author(s):  
Mina Zafarpiran ◽  
Roya Sharifi ◽  
Zeinab Shirvani-Farsani
Keyword(s):  
Multiple Sclerosis ◽  
Gene Regulation ◽  
Binding Sites ◽  
Target Genes ◽  
Demyelinating Disease ◽  
Target Prediction ◽  
Computational Prediction ◽  
Functional Verification ◽  
Candidate Snps ◽  
Inflammatory Genes

Background: Multiple Sclerosis (MS) is an inflammatory and demyelinating disease of the central nervous system, and genetic factors play an important role in its susceptibility. The expressions of many inflammatory genes implicated in MS are regulated by microRNA (miRNAs), whose function is to suppress the translation by pairing with miRNA Recognition Elements (MREs) present in the 3' untranslated region (3'UTR) of target mRNA. Recently, it has been shown that the Single Nucleotide Polymorphism (SNPs) present within the 3'UTR of mRNAs can affect the miRNA-mediated gene regulation and susceptibility to a variety of human diseases. Objective: The aim of this study was to analyze the SNPs within the 3'UTR of miRNA inflammatory target genes related to multiple sclerosis. Methods: By DisGeNET, dbGaP, Ovid, DAVID, Web of knowledge, and SNPs databases, 3'UTR genetic variants were identified in all inflammatory genes associated with MS. Also, miRNA's target prediction databases were used for predicting the miRNA binding sites. Results: We identified 125 SNPs with MAF>0.05 located in the binding site of the miRNA of 35 genes among 59 inflammatory genes related to MS. Bioinformatics analysis predicted 62 MRE-modulating SNPs and 59 MRE-creating SNPs in the 3'UTR of MSimplicated inflammatory genes. These candidate SNPs within miRNA binding sites of inflammatory genes can alter the miRNAs binding, and consequently lead to the mRNA gene regulation. Conclusion: Therefore, these miRNA and MRE-SNPs may play important roles in personalized medicine of MS, and hence, they would be valuable for further functional verification investigations.

scholarly journals Secondary haemophagocytic lymphohistiocytosis in COVID-19: correlation of the autopsy findings of bone marrow haemophagocytosis with HScore

2021 ◽  
pp. jclinpath-2020-207337
Author(s):  
Claudia Núñez-Torrón ◽  
Ana Ferrer-Gómez ◽  
Esther Moreno Moreno ◽  
Belen Pérez-Mies ◽  
Jesús Villarrubia ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Immune Response ◽  
Immune System ◽  
Multiorgan Failure ◽  
Histological Findings ◽  
Haemophagocytic Lymphohistiocytosis ◽  
Bone Marrow Tissue ◽  
Autopsy Findings ◽  
Specific Finding ◽  
Clinical Records

BackgroundSecondary haemophagocytic lymphohistiocytosis (sHLH) is characterised by a hyper activation of immune system that leads to multiorgan failure. It is suggested that excessive immune response in patients with COVID-19 could mimic this syndrome. Some COVID-19 autopsy studies have revealed the presence of haemophagocytosis images in bone marrow, raising the possibility, along with HScore parameters, of sHLH.AimOur objective is to ascertain the existence of sHLH in some patients with severe COVID-19.MethodsWe report the autopsy histological findings of 16 patients with COVID-19, focusing on the presence of haemophagocytosis in bone marrow, obtained from rib squeeze and integrating these findings with HScore parameters. CD68 immunohistochemical stains were used to highlight histiocytes and haemophagocytic cells. Clinical evolution and laboratory parameters of patients were collected from electronic clinical records.ResultsEleven patients (68.7%) displayed moderate histiocytic hyperplasia with haemophagocytosis (HHH) in bone marrow, three patients (18.7%) displayed severe HHH and the remainder were mild. All HScore parameters were collected in 10 patients (62.5%). Among the patients in which all parameters were evaluable, eight patients (80%) had an HScore >169. sHLH was not clinically suspected in any case.ConclusionsOur results support the recommendation of some authors to use the HScore in patients with severe COVID-19 in order to identify those who could benefit from immunosuppressive therapies. The presence of haemophagocytosis in bone marrow tissue, despite not being a specific finding, has proved to be a very useful tool in our study to identify these patients.

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