title: Identification of the Fcalpha/muR isoform specifically expressed in the kidney tubules.
abstract: Fcalpha/muR is expressed not only in lymphoid, but also in non-lymphoid organs, including kidney. However, molecular and functional characteristics of Fcalpha/muR, particularly expressed in non-lymphoid organs, have remained unclear. Here we identified an isoform of Fcalpha/muR in the murine kidney on the C57BL/6J background. The kidney expressed only the isoform, which was not expressed in other lymphoid and non-lymphoid organs, and this isoform binds both IgA and IgM. Immunohistochemical analyses suggested that the Fcalpha/muR isoform was expressed in the tubular epithelial cells, but not in the glomeruli. This was confirmed by flow cytometry analysis of isolated tubular epithelial cells and by RT-PCR analyses using the separately excised glomerular and tubular regions by the laser microdissection system. These results suggest that Fcalpha/muR may not be involved in IgA deposition in glomerular mesangium cells in IgA nephropathy. Rather, it may play an important role in immunity in the renal tubular regions.
authors.affiliation: Department of Immunology, Institute of Basic Medical Sciences, Graduate School of Comprehensive Human Sciences, and Center for TARA, University of Tsukuba, 1-1-1 Ten-nodai, Tsukuba, Ibaraki 305-8575, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Kurita
authors.forename: Shin-Ichiro
authors.initials: S
authors.lastname: Honda
authors.forename: Kenta
authors.initials: K
authors.lastname: Usui
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Shimizu
authors.forename: Akitomo
authors.initials: A
authors.lastname: Miyamoto
authors.forename: Satoko
authors.initials: S
authors.lastname: Tahara-Hanaoka
authors.forename: Kazuko
authors.initials: K
authors.lastname: Shibuya
authors.forename: Akira
authors.initials: A
authors.lastname: Shibuya
mesh_terms: D000818:Animals; D004847:Epithelial Cells / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D007070:Immunoglobulin A / Q000276:immunology / Q000378:metabolism; D007075:Immunoglobulin M / Q000276:immunology / Q000378:metabolism; D007678:Kidney Glomerulus / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D007684:Kidney Tubules / Q000276:immunology / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D020033:Protein Isoforms / Q000276:immunology / Q000378:metabolism; D011961:Receptors, Fc / Q000276:immunology / Q000378:metabolism*
chemical_list: C526791:Fcalpha-mu protein, mouse; D007070:Immunoglobulin A; D007075:Immunoglobulin M; D020033:Protein Isoforms; D011961:Receptors, Fc