| 1. |
- Ahlqvist, Emma, et al.
(author)
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Fragmentation of two quantitative trait loci controlling collagen-induced arthritis reveals a new set of interacting subloci
- 2007
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In: Journal of Immunology. - 1550-6606. ; 178:5, s. 3084-3090
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Journal article (peer-reviewed)abstract
- Linkage analysis of F-2 crosses has led to identification of large numbers of quantitative trait loci (QTL) for complex diseases, but identification of the underlying genes has been more difficult. Reasons for this could be complications that arise from separation of interacting or neighboring loci. We made a partial advanced intercross (PAI) to characterize and fine-map linkage to collagen-induced arthritis in two chromosomal regions derived from the DBA/1 strain and crossed into the B10.Q strain: Cia7 on chromosome 7 and a locus on chromosome 15. Only Cia7 was detected by a previous F-2 cross. Linkage analysis of the PAI revealed a different linkage pattern than the F-2 cross, adding multiple loci and strong linkage to the previously unlinked chromosome 15 region. Subcongenic strains derived from animals in the PAI confirmed the loci and revealed additional subloci. In total, no less than seven new loci were identified. Several loci interacted and three loci were protective, thus partly balancing the effect of the disease-promoting loci. Our results indicate that F-2 crosses do not reveal the full complexity of identified QTLs, and that detection is more dependent on the genetic context of a QTL than the potential effect of the underlying gene.
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| 2. |
- Ahlqvist, Emma, et al.
(author)
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High-resolution mapping of a complex disease, a model for rheumatoid arthritis, using heterogeneous stock mice
- 2011
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In: Human Molecular Genetics. - Oxford : Oxford University Press. - 0964-6906 .- 1460-2083. ; 20:15, s. 3031-3041
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Journal article (peer-reviewed)abstract
- Resolving the genetic basis of complex diseases like rheumatoid arthritis will require knowledge of the corresponding diseases in experimental animals to enable translational functional studies. Mapping of quantitative trait loci in mouse models of arthritis, such as collagen-induced arthritis (CIA), using F(2) crosses has been successful, but can resolve loci only to large chromosomal regions. Using an inbred-outbred cross design, we identified and fine-mapped CIA loci on a genome-wide scale. Heterogeneous stock mice were first intercrossed with an inbred strain, B10.Q, to introduce an arthritis permitting MHCII haplotype. Homozygous H2(q) mice were then selected to set up an F(3) generation with fixed major histocompatibility complex that was used for arthritis experiments. We identified 26 loci, 18 of which are novel, controlling arthritis traits such as incidence of disease, severity and time of onset and fine-mapped a number of previously mapped loci. © The Author 2011. Published by Oxford University Press. All rights reserved.
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| 3. |
- Ahlqvist, Emma, et al.
(author)
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The value of animal models in predicting genetic susceptibility to complex diseases such as rheumatoid arthritis.
- 2009
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In: Arthritis Research and Therapy. - : Springer Science and Business Media LLC. - 1478-6362 .- 1478-6354. ; 11:3
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Research review (peer-reviewed)abstract
- ABSTRACT: For a long time, genetic studies of complex diseases were most successfully conducted in animal models. However, the field of genetics is now rapidly evolving, and human genetics has also started to produce strong candidate genes for complex diseases. This raises the question of how to continue gene-finding attempts in animals and how to use animal models to enhance our understanding of gene function. In this review we summarize the uses and advantages of animal studies in identification of disease susceptibility genes, focusing on rheumatoid arthritis. We are convinced that animal genetics will remain a valuable tool for the identification and investigation of pathways that lead to disease, well into the future.
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| 4. |
- Forster, M., et al.
(author)
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Genetic control of antibody production during collagen-induced arthritis development in heterogeneous stock mice
- 2012
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In: Arthritis and Rheumatism. - : Wiley. - 0004-3591 .- 1529-0131. ; 71
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Journal article (peer-reviewed)abstract
- OBJECTIVE: To identify genetic factors driving pathogenic autoantibody formation in collagen-induced arthritis (CIA), a mouse model of rheumatoid arthritis (RA), in order to better understand the etiology of RA and identify possible new avenues for therapeutic intervention. METHODS: We performed a genome-wide analysis of quantitative trait loci controlling autoantibody to type II collagen (anti-CII), anti-citrullinated protein antibody (ACPA), and rheumatoid factor (RF). To identify loci controlling autoantibody production, we induced CIA in a heterogeneous stock-derived mouse cohort, with contribution of 8 inbred mouse strains backcrossed to C57BL/10.Q. Serum samples were collected from 1,640 mice before arthritis onset and at the peak of the disease. Antibody concentrations were measured by standard enzyme-linked immunosorbent assay, and linkage analysis was performed using a linear regression-based method. RESULTS: We identified loci controlling formation of anti-CII of different IgG isotypes (IgG1, IgG3), antibodies to major CII epitopes (C1, J1, U1), antibodies to a citrullinated CII peptide (citC1), and RF. The anti-CII, ACPA, and RF responses were all found to be controlled by distinct genes, one of the most important loci being the immunoglobulin heavy chain locus. CONCLUSION: This comprehensive genetic analysis of autoantibody formation in CIA demonstrates an association not only of anti-CII, but interestingly also of ACPA and RF, with arthritis development in mice. These results underscore the importance of non-major histocompatibility complex genes in controlling the formation of clinically relevant autoantibodies.
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| 5. |
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| 6. |
- Raposo, Bruno, et al.
(author)
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System A amino acid transporters regulate glutamine uptake and attenuate antibody-mediated arthritis
- 2015
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In: Immunology. - Chichester : Wiley-Blackwell Publishing Inc.. - 0019-2805 .- 1365-2567. ; 146:4, s. 607-617
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Journal article (peer-reviewed)abstract
- Proliferation of rapidly dividing bone marrow-derived cells is strongly dependent on the availability of free glutamine, whose uptake is mediated through different amino acid transporters. The sodium-coupled neutral amino acid transporter (SNAT) family was previously reported to be associated with the development of collagen-induced arthritis in mice. Here, we tested the hypothesis whether impairment of SNAT proteins influences immune cell function and in turn alters arthritis development. The 2-(methylamino)isobutyric acid (MeAIB), a SNAT-specific substrate, was used to modulate the function of SNAT proteins. We demonstrate that glutamine uptake by murine naive lymphocytes, and consequent cell proliferation, is strongly associated with system A transporters. Physiological impairment of SNAT proteins reduced the antibody-initiated effector phase of arthritis, mainly by affecting the levels of circulating monocytes and neutrophils. MeAIB was also shown to affect the proliferation of immortalized cells, through trans-inhibition of SNAT proteins. Based on our observations, we conclude that SNAT proteins regulate the initial stages of lymphocyte activation by regulating glutamine uptake, and that the effector phase of arthritis can be affected by non-metabolized SNAT substrates. Most probably, metabolically active cells within both the adaptive and the innate immune systems are regulated by SNAT proteins and play a role in modifying arthritis development. © 2015 John Wiley & Sons Ltd.
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