title: Expression of Kidney Injury Molecule-1 in Healthy and Diseased Feline Kidney Tissue.
abstract: Sensitive markers to detect acute kidney injury (AKI) in cats are lacking. Kidney injury molecule-1 (KIM-1) is a promising marker of acute tubular injury in humans, and sequence and structure of feline KIM-1 have been determined. KIM-1 is shed into urine of cats with natural AKI. The objectives of this study were to characterize temporal and cellular expression of KIM-1 in kidneys from cats without and with experimental and natural AKI using histopathology and immunohistochemistry. Tissue sections from 8 cats without kidney disease, 3 to 4 cats with experimentally induced AKI on each day 1, 3, 6, and 12 after unilateral ischemia/reperfusion, and 9 cats with natural AKI were assessed. In sections from cats without kidney disease, patterns of periodic acid-Schiff and aquaporin-1 staining allowed identification of 3 distinct segments of the proximal tubule. KIM-1 staining was absent in segments 1 (S1) and S2, and faint in S3. Injury of S3 in cats with experimental and natural AKI was characterized by cell loss and necrosis, and remaining intact cells had cytoplasmic blebs and reduced brush borders. In experimental AKI, intensity of KIM-1 expression increased in proportion to the severity of injury and was consistently present in S3 but only transiently in other segments. Vimentin was absent in proximal tubules of healthy cats but expressed in injured S3. These findings indicate that S3 is the proximal tubular segment most susceptible to ischemic injury and that KIM-1 is a sensitive tissue indicator of AKI in cats.
authors.affiliation: 1 Department of Pathobiology, University of Guelph, Guelph, Ontario, Canada.
authors.forename: S K
authors.initials: SK
authors.lastname: Bland
authors.affiliation: 2 Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, GA, USA.
authors.forename: C W
authors.initials: CW
authors.lastname: Schmiedt
authors.affiliation: 1 Department of Pathobiology, University of Guelph, Guelph, Ontario, Canada.
authors.forename: M E
authors.initials: ME
authors.lastname: Clark
authors.affiliation: 3 Animal Health Laboratory, University of Guelph, Guelph, Ontario, Canada.
authors.forename: J
authors.initials: J
authors.lastname: DeLay
authors.affiliation: 1 Department of Pathobiology, University of Guelph, Guelph, Ontario, Canada.
authors.forename: D
authors.initials: D
authors.lastname: Bienzle
mesh_terms: D000818:Animals; D016022:Case-Control Studies; D002371:Cat Diseases / Q000378:metabolism* / Q000473:pathology; D002415:Cats / Q000378:metabolism; D005260:Female; D000072596:Hepatitis A Virus Cellular Receptor 1 / Q000378:metabolism*; D007668:Kidney / Q000378:metabolism* / Q000473:pathology; D008297:Male
chemical_list: D000072596:Hepatitis A Virus Cellular Receptor 1
keywords: IRIS; acute kidney injury; acute renal failure; aquaporin; cat; immunohistochemistry; proximal tubule; urinary tract; vimentin