The effects of MyD88 deficiency on disease phenotype in dysferlin-deficient A/J mice: Role of endogenous toll-like receptor (TLR) ligands
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE46420 | GEO | 2013/04/27
SECONDARY ACCESSION(S): PRJNA200304
REPOSITORIES: GEO
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Project description:Genome wide expression study of the effect of single stranded RNA (ssRNA) in A/JOlaHsd (WT), A/J and A/J-MyD88 deficient mice. The hypothesis for this study was that endogenous TLR ligands released from the leaking dysferlin-deficient muscle fibers engage TLRs on muscle and immune cells and contribute to disease progression.These data point to a clear role for the TLR pathway in the pathogenesis of dysferlin deficiency. Total RNA obtained from isolated tibalis anterior muscles (TA) of A/JOlaHsd (WT), A/J and A/J-MyD88 deficient mice that were subjected to 3 intramuscular injections of ssRNA over the period of 10 days compared to their contraleteral legs that were injected with saline (control).
2013-04-27 | E-GEOD-46420 | biostudies-arrayexpress
Project description:Among both healthy and immunocompromised patient populations, pneumonia is a leading cause of death worldwide. Yet, despite structural vulnerability resulting in recurrent exposure to pathogens, the lungs’ mucosal immunity successfully suppresses most infections. We recently reported that these innate defenses can be substantially augmented by inhalational exposure to a crude bacterial lysate, protecting broadly against respiratory pathogens, including lethal pneumonia caused by bacteria, fungi or viruses. The phenomenon of inducible resistance is associated with rapid pathogen killing in the lungs and persists in the absence of the typical leukocytes of innate immunity. Rather, the respiratory epithelium appears to be the predominant effector. Toll-like receptors (TLRs) are highly conserved pattern recognition receptors crucial to host defense through the sensing of pathogen associated molecular patterns. Given the importance of TLRs to mucosal immunity, the presence of numerous pathogen associated molecular patterns in the bacterial lysate, and the induction of many TLR-dependent genes following lysate treatment, we hypothesized that induced resistance follows simultaneous stimulation of multiple TLRs. To test this, we challenged mice deficient in TLR/IL1R adaptor proteins and found that resistance could not be induced in mice lacking MyD88. Having identified this phenomenon to be MyD88-dependent, we sought to determine whether the protective phenomenon could be recapitulated by treatment with synthetic TLR agonists. Mice were treated with aerosolized TLR ligands, alone and in combination, prior to infection with virulent pathogens. While limited protection against pneumonia was afforded by the individual TLR ligands, we discovered that the synergistic combination of diacylated lipopetide TLR2/6 agonist Pam2CSK4 and CpG oligodeoxynucleotide TLR9 agonist ODN2395 induced profound resistance against all tested pathogens. This combination also induced greater than additive pathogen killing in the lungs of challenged mice, and we found that the combination could effectively induce pathogen killing by respiratory epithelial cells in vitro. In order to better understand the mechanisms underlying the inducible pathogen killing by this unique combination of TLR agonists, we performed microarray analysis of murine MLE-15 respiratory epithelial cells following 4 h treatment with PBS (sham treatment), Pam2CSK4 alone, ODN2395 alone, or the combination of both agonists, using Illumina Sentrix MouseRef-8 v2 BeadChips. This allows for assessment of differential gene expression, not only between treated and untreated, but between single and combination treated. The intent of the experiment is to gain insight into the transcriptionally-regulated means by which TLR2/6 and TLR9 signaling pathways synergistically interact. Keywords: Differential expression, epithelium, in vitro
2009-10-30 | GSE18725 | GEO
Project description:TLRs are considered important for innate immune responses that combat bacterial infections. Here, the role of TLRs in severe septic peritonitis using the colon ascendens stent peritonitis (CASP) model was examined. We demonstrate that mice deficient for MyD88 and TRIF had markedly reduced bacterial numbers both in peritoneal cavity and peripheral blood, indicating that bacterial clearance in this model is inhibited by TLR signals. Moreover, survival of Myd88-/-;TrifLps2/Lps2 mice was significantly improved. The lack of TLR signals prevented the excessive induction of inflammatory cytokines and of IL 10. Notably, the expression of IFN-gamma, which has an essential protective role in septic peritonitis, and of IFN-regulated genes including several p47 and p65 GTPases as well as IP 10 was independent of TLR signaling. These results provide evidence that, in severe septic peritonitis, TLR deficiency balances the innate immune response in a favorable manner by attenuating deleterious responses such as excessive cytokine release, while leaving intact protective IFN-gamma production. In this dataset, expression data of genes induced by septic peritonitis in spleens from TLR-deficient and wildtype mice are included. 3 groups (septic TLR-deficient mice, septic wildtype mice, and untreated wildtype mice) with 4 replicates each.
2011-06-27 | E-GEOD-24327 | biostudies-arrayexpress
Project description:In the activated B-cell-like (ABC) subtype of diffuse large B cell lymphoma (DLBCL), the most frequent gain-of-function mutations target MyD88, a signaling adapter for Tolllike receptors (TLRs). The most prevalent oncogenic mutant, MyD88 L265P, occurs in 29% of cases and is the most active in engaging the NF-kappaB pathway. Here we show that MyD88 mutants do not function autonomously, but rather require TLR7, TLR9, and to a lesser extent, TLR4 to promote the survival of ABC DLBCL cells. Unlike wild type MyD88, MyD88 mutants associate constitutively with TLR7 and TLR9 in ABC DLBCL cells. Like ligand-induced TLR7/9 signaling in normal immune cells, the survival of ABC DLBCL cell lines depends upon translocation of TLR7 and TLR9 to acidic endolysosomes, where proteolytic processing of their ligand binding ectodomains is required for their oncogenic signaling. ABC DLBCL viability also depends upon CD14, a co-receptor for TLR7 and TLR9 that promotes engagement of nucleic acid ligands by these receptors. Point mutations in the TLR7 or TLR9 ectodomains that abrogate ligand binding and/or signaling were incapable of sustaining ABC DLBCL survival. An inhibitory oligonucleotide that suppresses TLR9 responses in normal B cells blocked NF-kappaB signaling and survival of ABC DLBCL lines. Together, these data suggest that an endogenous TLR ligand may play a pathogenic role in ABC DLBCL and provide a rationale for targeting TLR signaling to improve therapy of this aggressive lymphoma. Gene expression was analyzed using Agilent human 2-color 4X44K oligo gene expression arrays. Cell line, TMD8 ABC-DLBCL, was infected with control (shControl, Cy3), shLTR7 (Cy5) or shLTR9 (Cy5) and changes in gene expression were monitored on day 1 and day 2 after induction of the shRNA with doxycycline, co-hybridizing control and experimental samples (Cy3+Cy5), for a total of 4 arrays.
2014-05-21 | E-GEOD-47147 | biostudies-arrayexpress
Project description:In the activated B-cell-like (ABC) subtype of diffuse large B cell lymphoma (DLBCL), the most frequent gain-of-function mutations target MyD88, a signaling adapter for Tolllike receptors (TLRs). The most prevalent oncogenic mutant, MyD88 L265P, occurs in 29% of cases and is the most active in engaging the NF-kappaB pathway. Here we show that MyD88 mutants do not function autonomously, but rather require TLR7, TLR9, and to a lesser extent, TLR4 to promote the survival of ABC DLBCL cells. Unlike wild type MyD88, MyD88 mutants associate constitutively with TLR7 and TLR9 in ABC DLBCL cells. Like ligand-induced TLR7/9 signaling in normal immune cells, the survival of ABC DLBCL cell lines depends upon translocation of TLR7 and TLR9 to acidic endolysosomes, where proteolytic processing of their ligand binding ectodomains is required for their oncogenic signaling. ABC DLBCL viability also depends upon CD14, a co-receptor for TLR7 and TLR9 that promotes engagement of nucleic acid ligands by these receptors. Point mutations in the TLR7 or TLR9 ectodomains that abrogate ligand binding and/or signaling were incapable of sustaining ABC DLBCL survival. An inhibitory oligonucleotide that suppresses TLR9 responses in normal B cells blocked NF-kappaB signaling and survival of ABC DLBCL lines. Together, these data suggest that an endogenous TLR ligand may play a pathogenic role in ABC DLBCL and provide a rationale for targeting TLR signaling to improve therapy of this aggressive lymphoma.
2014-05-21 | GSE47147 | GEO
Project description:Infectious pneumonias exact an unacceptable mortality burden worldwide. Efforts to protect populations from pneumonia have historically focused on antibiotic development and vaccine-enhanced adaptive immunity. However, we have recently reported that the lungs’ innate defenses can be therapeutically induced by inhalation of a bacterial lysate that protects mice against otherwise lethal pneumonia. Here, we tested in mice the hypothesis that Toll-like receptors (TLRs) are required for this antimicrobial phenomenon, and found that resistance could not be induced in the absence of the TLR signaling adaptor protein MyD88. We then attempted to recapitulate the protection afforded by the bacterial lysate by stimulating the lung epithelium with aerosolized synthetic TLR ligands. While most single or combination treatments yielded no protection, simultaneous treatment with ligands for TLR2/6 and TLR9 conferred robust, synergistic protection against virulent Gram-positive and Gram-negative pathogens. Protection was associated with rapid pathogen killing in the lungs, and pathogen killing could be induced from lung epithelial cells in isolation. Taken together, these data demonstrate the requirement for TLRs in inducible resistance against pneumonia, reveal a remarkable, unanticipated synergistic interaction of TLR2/6 and TLR9, reinforce the emerging evidence supporting the antimicrobial capacity of the lung epithelium, and may provide the basis for a novel clinical therapeutic that can protect patients against pneumonia during periods of peak vulnerability. MLE-15 cells were treated with 20 ul volumes of PBS (sham treatment), ODN2395 (0.4 ug), Pam2CSK4 (0.2 ug) or ODN2395+Pam2CSK4. At least 5 unique samples per group. Treated for 2 hours. Hybridized to Illumina Sentrix MouseRef-8 v2 Beadhips.
2011-01-27 | E-GEOD-26864 | biostudies-arrayexpress
Project description:Infectious pneumonias exact an unacceptable mortality burden worldwide. Efforts to protect populations from pneumonia have historically focused on antibiotic development and vaccine-enhanced adaptive immunity. However, we have recently reported that the lungs’ innate defenses can be therapeutically induced by inhalation of a bacterial lysate that protects mice against otherwise lethal pneumonia. Here, we tested in mice the hypothesis that Toll-like receptors (TLRs) are required for this antimicrobial phenomenon, and found that resistance could not be induced in the absence of the TLR signaling adaptor protein MyD88. We then attempted to recapitulate the protection afforded by the bacterial lysate by stimulating the lung epithelium with aerosolized synthetic TLR ligands. While most single or combination treatments yielded no protection, simultaneous treatment with ligands for TLR2/6 and TLR9 conferred robust, synergistic protection against virulent Gram-positive and Gram-negative pathogens. Protection was associated with rapid pathogen killing in the lungs, and pathogen killing could be induced from lung epithelial cells in isolation. Taken together, these data demonstrate the requirement for TLRs in inducible resistance against pneumonia, reveal a remarkable, unanticipated synergistic interaction of TLR2/6 and TLR9, reinforce the emerging evidence supporting the antimicrobial capacity of the lung epithelium, and may provide the basis for a novel clinical therapeutic that can protect patients against pneumonia during periods of peak vulnerability.
2011-01-27 | GSE26864 | GEO
Project description:Repair of injured muscle involves repair of injured myofibers through the involvement of dysferlin and its interacting partners, including annexin. Studies with mice and patients have established that dysferlin deficit leads to chronic inflammation and adipogenic replacement of the diseased muscle. However, longitudinal analysis of annexin deficit on muscle pathology and function is lacking. Here we show that unlike annexin A1, but similar to dysferlin, lack of annexin A2 (AnxA2) causes poor myofiber repair and progressive weakening with age. However, unlike dysferlin-deficient muscle, AnxA2-deficient muscles do not exhibit chronic inflammation or adipogenic replacement. Deletion of AnxA2 in dysferlin deficient mice reduces inflammation, adipogenic replacement, and loss in muscle function caused by dysferlin deficit. These results show that: a) AnxA2 facilitates myofiber repair, b) chronic inflammation and adipogenic replacement of dysferlinopathic muscle requires AnxA2, and c) inhibiting AnxA2-mediated inflammation is a novel therapeutic avenue for dysferlinopathy.
2016-10-04 | GSE87557 | GEO
Project description:Dysferlin is expressed in skeletal and cardiac muscle. However, dysferlin deficiency, namely limb girdle muscular dystrophy 2B (LGMD2B) and Myoshi myopathy, results in skeletal muscle weakness and spares the heart. This dichotomy could be caused by differential regulation of protective mechanisms. Therefore, we compared intraindividual mRNA expression profiles between cardiac and skeletal muscle in dysferlin-deficient SJL/J mice and normal C57BL/6 mice. Experiment Overall Design: 20 chips were analyzed. They represent 4 groups of 5 replicates each. Experiment Overall Design: The 4 groups are cardiac (LV) and skeletal muscle of normal and dysferlin deficient mice. Experiment Overall Design: Tissues from normal mice are the controls in comparison to tissues of dysferlin deficient mice.
2007-09-04 | E-GEOD-2507 | biostudies-arrayexpress
Project description:TLRs are considered important for innate immune responses that combat bacterial infections. Here, the role of TLRs in severe septic peritonitis using the colon ascendens stent peritonitis (CASP) model was examined. We demonstrate that mice deficient for MyD88 and TRIF had markedly reduced bacterial numbers both in peritoneal cavity and peripheral blood, indicating that bacterial clearance in this model is inhibited by TLR signals. Moreover, survival of Myd88-/-;TrifLps2/Lps2 mice was significantly improved. The lack of TLR signals prevented the excessive induction of inflammatory cytokines and of IL 10. Notably, the expression of IFN-gamma, which has an essential protective role in septic peritonitis, and of IFN-regulated genes including several p47 and p65 GTPases as well as IP 10 was independent of TLR signaling. These results provide evidence that, in severe septic peritonitis, TLR deficiency balances the innate immune response in a favorable manner by attenuating deleterious responses such as excessive cytokine release, while leaving intact protective IFN-gamma production.
2011-06-28 | GSE24327 | GEO