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| 2. |
- Bergman, Petra, et al.
(författare)
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Next-generation sequencing identifies microRNAs that associate with pathogenic autoimmune neuroinflammation in rats.
- 2013
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Ingår i: Journal of Immunology. - : The American Association of Immunologists. - 0022-1767 .- 1550-6606. ; 190:8, s. 4066-75
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Tidskriftsartikel (refereegranskat)abstract
- MicroRNAs (miRNAs) are known to regulate most biological processes and have been found dysregulated in a variety of diseases, including multiple sclerosis (MS). In this study, we characterized miRNAs that associate with susceptibility to develop experimental autoimmune encephalomyelitis (EAE) in rats, a well-established animal model of MS. Using Illumina next-generation sequencing, we detected 544 miRNAs in the lymph nodes of EAE-susceptible Dark Agouti and EAE-resistant Piebald Virol Glaxo rats during immune activation. Forty-three miRNAs were found differentially expressed between the two strains, with 81% (35 out of 43) showing higher expression in the susceptible strain. Only 33% of tested miRNAs displayed differential expression in naive lymph nodes, suggesting that a majority of regulated miRNAs are EAE dependent. Further investigation of a selected six miRNAs indicates differences in cellular source and kinetics of expression. Several of the miRNAs, including miR-146a, miR-21, miR-181a, miR-223, and let-7, have previously been implicated in immune system regulation. Moreover, 77% (33 out of 43) of the miRNAs were associated with MS and other autoimmune diseases. Target genes likely regulated by the miRNAs were identified using computational predictions combined with whole-genome expression data. Differentially expressed miRNAs and their targets involve functions important for MS and EAE, such as immune cell migration through targeting genes like Cxcr3 and cellular maintenance and signaling by regulation of Prkcd and Stat1. In addition, we demonstrated that these three genes are direct targets of miR-181a. Our study highlights the impact of multiple miRNAs, displaying diverse kinetics and cellular sources, on development of pathogenic autoimmune inflammation.
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| 3. |
- Gillett, Alan
(författare)
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Genetic and immunological mechanisms regulating neuroinflammation
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Multiple sclerosis (MS) is the most common neurological disorder in young adults and imposes both health and socioeconomic burdens on society. The cause and aetiology of MS are incompletely understood and current treatments are inadequate. Pathologically, prolonged chronic inflammation and widespread demyelination in the central nervous system leads to atrophy and progressive worsening of disease. This thesis combined use of in vivo animal models, in vitro cellular assays and in silico computational methods to characterise pathogenic mechanisms and translate findings from models to human disease. The animal model of MS, experimental autoimmune encephalomyelitis (EAE), was evaluated in light of novel findings in MS aetiology and further analyzed to explore differences in strain susceptibility. Susceptible rats had increased interleukin 7 receptor (Il7r) and Il2ra expression as well as altered isoform signatures in naïve lymphoid tissue, setting the stage for T cell differentiation towards pathogenic T helper 1 (TH1) and TH17 subtypes. Moreover, increased Il18r1 expression described in susceptible rats was explored in MS. Dysregulation of this receptor can mediate disease initiation through T cell differentiation as well as T cell and macrophage activation. IL18R1 levels were increased in peripheral immune and central nervous tissues in MS. Inflammatory molecules that are dysregulated in EAE likely represent true pathogenic mechanisms in humans. Multiple approaches were used to define tumour necrosis factor (TNF) regulation of disease severity. A region on chromosome 4 in the rat regulated TNF production in macrophages following innate inflammatory stimulation. Additional inflammatory molecules were also genetically regulated, modifying the cellular phenotype and severity of multiple diseases. This specific inflammatory control provides insight into disease pathogenesis and future treatment options. The approach of combining genetic and immunological approaches in both models and human samples will continue to improve disease understanding and provide novel therapeutics through identification of key regulators and general immune and non-immune pathways.
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| 4. |
- Gillett, Alan, et al.
(författare)
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TNF production in macrophages is genetically determined and regulates inflammatory disease in rats.
- 2010
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Ingår i: Journal of immunology (Baltimore, Md. : 1950). - : The American Association of Immunologists. - 1550-6606 .- 0022-1767. ; 185:1, s. 442-50
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Tidskriftsartikel (refereegranskat)abstract
- Dysregulation of TNF is an important pathophysiological phenotype for many diseases. Recently, certain genetically regulated loci have been identified to regulate several inflammatory diseases. We hypothesized that a region on rat chromosome 4 known to regulate experimental autoimmune encephalomyelitis, experimental arthritis and experimental autoimmune neuritis harbors a gene regulating central inflammatory molecules, such as TNF. We therefore mapped TNF production using linkage analysis in the 12th generation of an advanced intercross line between DA and PVG.AV1 rats, which differ in susceptibility to several inflammatory conditions. A single TNF-regulating quantitative trait locus with a logarithm of odds score of 6.2 was identified and its biological effect was confirmed in a congenic rat strain. The profound TNF regulation mapped in congenic strains to the macrophage population. Several TLR signaling cascades led to the same reduced proinflammatory phenotype in congenic macrophages, indicating control of a convergence point for innate inflammatory activity. The decreased TNF potential and reduced proinflammatory macrophage phenotype in congenic rats was also associated with reduced clinical severity in experimental autoimmune encephalomyelitis, pristane-induced arthritis and sepsis experimental models. Determination of genes and mechanisms involved in this genetically determined TNF regulation will be valuable in understanding disease pathogenesis and aid treatment development.
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| 5. |
- Malmeström, Clas, 1965, et al.
(författare)
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Serum levels of LIGHT in MS
- 2013
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Ingår i: Multiple sclerosis (Houndmills, Basingstoke, England). - : SAGE Publications. - 1477-0970 .- 1352-4585. ; 19:7, s. 871-876
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Recently, a polymorphism in the LIGHT gene was shown to increase the risk of multiple sclerosis (MS) in a genome-wide association study (GWAS). OBJECTIVE: Our aim was to investigate if serum levels of LIGHT were affected by this polymorphism and by the disease itself. METHODS: Serum levels of LIGHT were investigated in four cohorts; 1) MS (n = 159) and controls (n = 160) in relation to rs1077667 genotype; 2) MS at relapse (n = 30) vs. healthy controls (n = 26); 3) MS (n = 27) vs. other neurological disease (OND, n = 33); and 4) MS patients before and after one year of treatment with natalizumab (n = 30). RESULTS: Carriers of the GG genotype had the lowest serum levels of LIGHT (p=0.02). Serum levels of LIGHT were increased in MS at relapse in two separate cohorts: vs. healthy controls (p=0.00005) and vs. remission (p=0.00006), other neurological disease (OND) (p=0.002) and OND with signs of inflammation (iOND; p=0.00005). Furthermore, serum levels of LIGHT were decreased by natalizumab treatment (p=0.001). CONCLUSION: Soluble LIGHT is an inhibitor of T-cell activation and GG carriers of rs1077667, with the highest risk for MS, had the lowest serum levels. The increased levels of LIGHT at times of increased MS activity suggest that soluble LIGHT is protective and may act to limit inflammation.
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| 6. |
- Parsa, Roham, et al.
(författare)
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Adoptive transfer of immunomodulatory M2 Macrophages prevents type 1 Diabetes in NOD Mice
- 2012
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Ingår i: Diabetes. - : American diabetes Association. - 0012-1797 .- 1939-327X. ; 61:11, s. 2881-2892
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Tidskriftsartikel (refereegranskat)abstract
- Macrophages are multifunctional immune cells that may either drive or modulate disease pathogenesis depending on their activation phenotype. Autoimmune type 1 diabetes (T1D) is a chronic proinflammatory condition characterized by unresolved destruction of pancreatic islets. Adoptive cell transfer of macrophages with immunosuppressive properties represents a novel immunotherapy for treatment of such chronic autoimmune diseases. We used a panel of cytokines and other stimuli to discern the most effective regimen for in vitro induction of immunosuppressive macrophages (M2r) and determined interleukin (IL)-4/IL-10/transforming growth factor-beta (TGF-beta) to be optimal. M2r cells expressed programmed cell death 1 ligand-2, fragment crystallizable region gamma receptor IIlb, IL-10, and TGF-beta, had a potent deactivating effect on proinflammatory lipopolysaccharide/interferon-gamma-stimulated macrophages, and significantly suppressed T-cell proliferation. Clinical therapeutic efficacy was assessed after adoptive transfer in NOD T1D mice, and after a single transfer of M2r macrophages, >80% of treated NOD mice were protected against T1D for at least 3 months, even when transfer was conducted just prior to clinical onset. Fluorescent imaging analyses revealed that adoptively transferred M2r macrophages specifically homed to the inflamed pancreas, promoting 3-cell survival. We suggest that M2r macrophage therapy represents a novel intervention that stops ongoing autoimmune T1D and may have relevance in a clinical setting. Diabetes 61:2881-2892, 2012
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| 7. |
- Watkins, Johnathan, et al.
(författare)
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Genomic Complexity Profiling Reveals That HORMAD1 Overexpression Contributes to Homologous Recombination Deficiency in Triple-Negative Breast Cancers
- 2015
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Ingår i: Cancer Discovery. - 2159-8274 .- 2159-8290. ; 5:5, s. 488-505
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Tidskriftsartikel (refereegranskat)abstract
- Triple-negative breast cancers (TNBC) are characterized by a wide spectrum of genomic alterations, some of which might be caused by defects in DNA repair processes such as homologous recombination (HR). Despite this understanding, associating particular patterns of genomic instability with response to therapy has been challenging. Here, we show that allelic-imbalanced copy-number aberrations (AiCNA) are more prevalent in TNBCs that respond to platinum-based chemotherapy, thus providing a candidate predictive biomarker for this disease. Furthermore, we show that a high level of AiCNA is linked with elevated expression of a meiosis-associated gene, HORMAD1. Elevated HORMAD1 expression suppresses RAD51-dependent HR and drives the use of alternative forms of DNA repair, the generation of AiCNAs, as well as sensitizing cancer cells to HR-targeting therapies. Our data therefore provide a mechanistic association between HORMAD1 expression, a specific pattern of genomic instability, and an association with response to platinum-based chemotherapy in TNBC. SIGNIFICANCE: Previous studies have shown correlation between mutational "scars" and sensitivity to platinums extending beyond associations with BRCA1/2 mutation, but do not elucidate the mechanism. Here, a novel allele-specific copy-number characterization of genome instability identifies and functionally validates the inappropriate expression of the meiotic gene HORMAD1 as a driver of HR deficiency in TNBC, acting to induce allelic imbalance and moderate platinum and PARP inhibitor sensitivity with implications for the use of such "scars" and expression of meiotic genes as predictive biomarkers.
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