title: A correlation between a proteomic evaluation and conventional measurements in the assessment of renal proximal tubular toxicity.
abstract: 4-Aminophenol (4-AP), D-serine, and cisplatin are established rodent nephrotoxins that damage proximal tubules within the renal cortex. Using high throughput 2D gel proteomics to profile protein changes in the plasma of compound-treated animals, we identified several markers of kidney toxicity. Male F344 and Alpk rats were treated with increasing doses of 4-AP, D-serine, or cisplatin, and plasma samples were collected over time. Control groups received saline or nontoxic isomers, L-serine, and transplatin. Plasma proteins that displayed dose- and temporal-dependent regulation in each study were further characterized by mass spectrometry to elucidate the protein identity. Several isoforms of the rat-specific T-kininogen protein were identified in each study. T-kininogen was elevated in the plasma of 4-AP-, D-serine-, and cisplatin-treated animals at early time points, returning to baseline levels 3 weeks after treatment. The protein was not elevated in the plasma of control animals or those treated with nontoxic compounds. We propose that T-kininogen may be required to counteract apoptosis in proximal tubular cells in order to minimize tissue damage following a toxic insult. In addition, T-kininogen may be required to stimulate localized inflammation to aid tissue repair. We also identified several isoforms of the inter-alpha inhibitor H4P heavy chain in the 4-AP and D-serine studies. In each case, the protein expression levels in the blood samples paralleled the extent of kidney toxicity, highlighting the correlation between protein alterations and clinical chemistry endpoints. A further set of proteins correlating with kidney damage was found to be a component of the complement cascade and other blood clotting factors, indicating a contribution of the immune system to the observed toxicity. These observations underscore the value of proteomics in identifying new biomarkers and in the elucidation of mechanisms of toxicity.
authors.affiliation: Oxford GlycoSciences (U.K.), Ltd., the Forum, 86 Milton Park, Abingdon, Oxon OX14 4RY, United Kingdom. lan.bandara@ogs.co.uk
authors.forename: Lasantha R
authors.initials: LR
authors.lastname: Bandara
authors.forename: Mike D
authors.initials: MD
authors.lastname: Kelly
authors.forename: Edward A
authors.initials: EA
authors.lastname: Lock
authors.forename: Sandy
authors.initials: S
authors.lastname: Kennedy
mesh_terms: D015761:4-Aminopyridine / Q000633:toxicity; D000818:Animals; D000970:Antineoplastic Agents / Q000633:toxicity; D001798:Blood Proteins / Q000378:metabolism; D002945:Cisplatin / Q000633:toxicity; D003404:Creatinine / Q000097:blood; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D005198:Fanconi Syndrome / Q000139:chemically induced* / Q000473:pathology*; D007091:Image Processing, Computer-Assisted; D007677:Kidney Function Tests; D007704:Kininogens / Q000096:biosynthesis; D008297:Male; D013058:Mass Spectrometry; D008970:Molecular Weight; D026902:Potassium Channel Blockers / Q000633:toxicity; D020543:Proteome / Q000737:chemistry / Q000187:drug effects*; D051381:Rats; D011916:Rats, Inbred F344; D012694:Serine / Q000633:toxicity; D000511:alpha-Macroglobulins / Q000378:metabolism
chemical_list: D000970:Antineoplastic Agents; D001798:Blood Proteins; D007704:Kininogens; D026902:Potassium Channel Blockers; D020543:Proteome; D000511:alpha-Macroglobulins; D012694:Serine; D003404:Creatinine; D015761:4-Aminopyridine; D002945:Cisplatin