TY - JOUR
T1 - GalNAc-T14 may Contribute to Production of Galactose-Deficient Immunoglobulin A1, the Main Autoantigen in IgA Nephropathy
AU - Jemelkova, Jana
AU - Stuchlova Horynova, Milada
AU - Kosztyu, Petr
AU - Zachova, Katerina
AU - Zadrazil, Josef
AU - Galuszkova, Dana
AU - Takahashi, Kazuo
AU - Novak, Jan
AU - Raska, Milan
N1 - Publisher Copyright:
© 2023 International Society of Nephrology
PY - 2023/5
Y1 - 2023/5
N2 - Introduction: Immunoglobulin A1 (IgA1) with galactose-deficient O-glycans (Gd-IgA1) play a key role in the pathogenesis of IgA nephropathy (IgAN). Mucosal-tissue infections increase IL-6 production and, in patients with IgAN, are often associated with macroscopic hematuria. IgA1-secreting cell lines derived from the circulation of patients with IgAN, compared to those of healthy controls (HCs), produce more IgA1 that has O-glycans with terminal or sialylated N-acetylgalactosamine (GalNAc). GalNAc residues are added to IgA1 hinge region by some of the 20 GalNAc transferases, the O-glycosylation-initiating enzymes. Expression of GALNT2, encoding GalNAc-T2, the main enzyme initiating IgA1 O-glycosylation, is similar in cells derived from patients with IgAN and HCs. In this report, we extend our observations of GALNT14 overexpression in IgA1-producing cell lines from patients with IgAN. Methods: GALNT14 expression was analyzed in peripheral blood mononuclear cells (PBMCs) from patients with IgAN and from HCs. Moreover, the effect of GALNT14 overexpression or knock-down on Gd-IgA1 production in Dakiki cells was assessed. Results: GALNT14 was overexpressed in PBMCs from patients with IgAN. IL-6 increased GALNT14 expression in PBMCs from patients with IgAN and HCs. We used IgA1-producing cell line Dakiki, a previously reported model of Gd-IgA1-producing cells, and showed that overexpression of GalNAc-T14 enhanced galactose deficiency of IgA1, whereas siRNA-mediated GalNAc-T14 knock-down reduced it. GalNAc-T14 was localized in trans-Golgi network, as expected. Conclusions: Overexpression of GALNT14 due to inflammatory signals during mucosal infections may contribute to overproduction of Gd-IgA1 in patients with IgAN.
AB - Introduction: Immunoglobulin A1 (IgA1) with galactose-deficient O-glycans (Gd-IgA1) play a key role in the pathogenesis of IgA nephropathy (IgAN). Mucosal-tissue infections increase IL-6 production and, in patients with IgAN, are often associated with macroscopic hematuria. IgA1-secreting cell lines derived from the circulation of patients with IgAN, compared to those of healthy controls (HCs), produce more IgA1 that has O-glycans with terminal or sialylated N-acetylgalactosamine (GalNAc). GalNAc residues are added to IgA1 hinge region by some of the 20 GalNAc transferases, the O-glycosylation-initiating enzymes. Expression of GALNT2, encoding GalNAc-T2, the main enzyme initiating IgA1 O-glycosylation, is similar in cells derived from patients with IgAN and HCs. In this report, we extend our observations of GALNT14 overexpression in IgA1-producing cell lines from patients with IgAN. Methods: GALNT14 expression was analyzed in peripheral blood mononuclear cells (PBMCs) from patients with IgAN and from HCs. Moreover, the effect of GALNT14 overexpression or knock-down on Gd-IgA1 production in Dakiki cells was assessed. Results: GALNT14 was overexpressed in PBMCs from patients with IgAN. IL-6 increased GALNT14 expression in PBMCs from patients with IgAN and HCs. We used IgA1-producing cell line Dakiki, a previously reported model of Gd-IgA1-producing cells, and showed that overexpression of GalNAc-T14 enhanced galactose deficiency of IgA1, whereas siRNA-mediated GalNAc-T14 knock-down reduced it. GalNAc-T14 was localized in trans-Golgi network, as expected. Conclusions: Overexpression of GALNT14 due to inflammatory signals during mucosal infections may contribute to overproduction of Gd-IgA1 in patients with IgAN.
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U2 - 10.1016/j.ekir.2023.02.1072
DO - 10.1016/j.ekir.2023.02.1072
M3 - Article
AN - SCOPUS:85150766012
SN - 2468-0249
VL - 8
SP - 1068
EP - 1075
JO - Kidney International Reports
JF - Kidney International Reports
IS - 5
ER -