title: Expression of the polymeric immunoglobulin receptor and excretion of secretory IgA in the postischemic kidney.
abstract: The humoral mucosal immune response of the kidney involves the transport of secretory IgA (S-IgA) through renal epithelial cells by the polymeric immunoglobulin receptor (pIgR). The pIgR is cleaved and released as free secretory component (FSC) or attached to IgA (S-IgA). We examined the effects of an ischemic model of acute renal failure (ARF) on the expression of pIgR and the secretion of FSC and S-IgA in the urine. Kidney pIgR mRNA levels decreased in ischemic animals by 55% at 4 h and by 85% at 72 h compared with controls. pIgR protein expression in the medullary thick ascending limb (TAL) decreased within 24 h and was nearly undetectable by 72 h. Urinary S-IgA and FSC concentrations decreased by 60% between days 3 and 6. pIgR mRNA and pIgR protein in the kidney returned to approximately 90% of control levels and urinary FSC and S-IgA concentrations returned to approximately 55% of control levels by day 7. We demonstrate that ischemic ARF decreases renal mucosal S-IgA transport in vivo and may contribute to the increased incidence of urinary tract infections.
mesh_terms: D058186:Acute Kidney Injury / Q000276:immunology / Q000378:metabolism; D000818:Animals; D015152:Blotting, Northern; D004847:Epithelial Cells / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D015870:Gene Expression / Q000502:physiology; D007071:Immunoglobulin A, Secretory / Q000652:urine*; D007511:Ischemia / Q000276:immunology / Q000378:metabolism*; D007686:Kidney Tubules, Distal / Q000737:chemistry / Q000166:cytology / Q000378:metabolism*; D008138:Loop of Henle / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D008297:Male; D009092:Mucous Membrane / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D009393:Nephritis / Q000276:immunology / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D019056:Receptors, Polymeric Immunoglobulin / Q000032:analysis / Q000235:genetics*; D012079:Renal Circulation / Q000276:immunology*; D014563:Urodynamics