Cellular and Molecular Biology


Autoimmune glomerulonephritis induced in congenic mouse strain carrying telomeric region of chromosome 1 derived from MRL/MpJ

Osamu Ichii1, Akihiro Konno1, Nobuya Sasaki2, Daiji Endoh3, Yoshiharu Hashimoto1 and Yasuhiro Kon1

1Laboratory of Anatomy, Department of Biomedical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, 2Laboratory of Experimental Animal Science, Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University and 3Department of Veterinary Radiology, School of Veterinary Medicine, Rakuno Gakuen University, Sapporo, Japan.

Offprint requests to: Yasuhiro Kon, Laboratory of Anatomy, Department of Biomedical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Kita 18-Nishi 9, Kita-ku, Sapporo, 060-0818, Japan. e-mail: y-kon@vetmed.hokudai.ac.jp

Summary. In lupus erythematosus-prone mice, including the BXSB, NZW and NZB strains, telomeric regions of chromosome 1 (Chr.1) contain major glomerulonephritis susceptibility loci such as Bxs3, Sle1, and Nba2. To assess whether strain MRL, a model for lupus erythematosus, had glomerulonephritis susceptibility loci on Chr.1, we created B6.MRLc1(82-100) congenic mice carrying MRL/MpJ Chr.1 (82-100cM) based on the C57BL/6 background and investigated renal pathology. From 6 months of age, B6.MRLc1 (82-100) showed the onset of diseases such as splenomegaly due to proliferation of CD3- or B220-positive cells, glomerular damage, and an increased serum anti-dsDNA antibody concentration, and these were earlier and severer in females. The score for glomerular damage was higher in B6.MRLc1(82-100) mice over 12 months old than in C57BL/6 or even in wild-type MRL/MpJ. Immune-complex depositions were demonstrated on glomerular basement membrane in B6.MRLc1(82-100) by immunohistochemistry and electron microscopy. For the percentage of IgG1-positive glomeruli, B6.MRLc1 (82-100) had significantly higher values than C57BL/6. In evaluations of clinical parameters, serum levels of blood urea nitrogen and the anti-dsDNA antibody in B6.MRLc1(82-100) were significantly higher than those in C57BL/6. In conclusion, B6.MRLc1(82-100) clearly developed autoimmune-mediated glomerulonephritis, and we demonstrated that MRL Chr.1 contained a novel glomerulonephritis susceptibility locus. We named this locus Mag (MRL autoimmune glomerulonephritis) and it provided new insights into the genetic basis and pathogenesis of lupus nephritis. Histol Histopathol 23, 411-422 (2008)

Key words: Autoimmunity, Chromosome 1, Glomerulonephritis, Kidney, MRL mice

DOI: 10.14670/HH-23.411