title: Noninvasive Biomarker Candidates for Cadmium-Induced Nephrotoxicity by 2DE/MALDI-TOF-MS and SILAC/LC-MS Proteomic Analyses.
abstract: Cadmium (Cd(2+)) is a major environmental pollutant that induces cytotoxicity by heavy-metal accumulation. Prolonged Cd(2+) exposure leads to cell damage by oxidative stress mainly in the kidneys, a critical organ for detoxification. To identify reliable on invasive protein biomarkers for Cd(2+)-induced nephrotoxicity, we performed 2-dimensional gel electrophoresis/matrix-assisted laser desorption/ionization time of flight mass spectra and stable isotope labeling by amino acids in cell culture/liquid chromatography-mass spectrometry analyses using conditioned media (CM) of HK-2 human kidney epithelial cells treated with CdCl2. Here, we identified heat shock cognate 71 kDa protein isoform1 (HSPA8) and α-enolase (ENO1) as potential biomarker candidates for the evaluation of Cd(2+)-induced nephrotoxicity. Treatment with CdCl2 increased the protein level of HSPA8 in CM and lysates of HK-2 cells. The mRNA level of HSPA8 was also increased by CdCl2 treatment, indicating transcriptional regulation. The level of ENO1 was increased in CM, but not in lysates of CdCl2-treated HK-2 cells. CdCl2 did not affect the mRNA level of ENO1. We provide evidence that the increases of HSPA8 and ENO1 in CM were due to Cd(2+)-induced cell death through oxidative stress. The increases of HSPA8 and ENO1 levels were also detected in CM of HK-2 cells treated with other nephrotoxic agents, such as HgCl2, NaAsO2, cisplatin, amphotericin B, and cyclosporine A. Urine and kidney tissues of CdCl2-treated rats showed increased levels of HSPA8. Taken together, this study identified HSPA8 and ENO1 as noninvasive biomarker candidates by 2 comparative proteomic analyses. These new biomarker candidates may have potential as alternatives to traditional biomarkers for the efficient and sensitive assessment of nephrotoxicity.
authors.affiliation: *College of Pharmacy, Duksung Women's University, Seoul 132-714, Republic of Korea; and.
authors.forename: Sun Young
authors.initials: SY
authors.lastname: Kim
authors.affiliation: *College of Pharmacy, Duksung Women's University, Seoul 132-714, Republic of Korea; and.
authors.forename: Hye Min
authors.initials: HM
authors.lastname: Lee
authors.affiliation: School of Pharmacy, Sungkyunkwan University, Suwon 440-746, Republic of Korea.
authors.forename: Kyeong Seok
authors.initials: KS
authors.lastname: Kim
authors.affiliation: School of Pharmacy, Sungkyunkwan University, Suwon 440-746, Republic of Korea.
authors.forename: Hyung Sik
authors.initials: HS
authors.lastname: Kim
authors.affiliation: *College of Pharmacy, Duksung Women's University, Seoul 132-714, Republic of Korea; and armoon@duksung.ac.kr.
authors.forename: Aree
authors.initials: A
authors.lastname: Moon
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism / Q000652:urine; D019256:Cadmium Chloride / Q000633:toxicity; D002105:Cadmium Poisoning / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology / Q000652:urine*; D002448:Cell Adhesion / Q000187:drug effects; D002460:Cell Line; D002851:Chromatography, High Pressure Liquid; D004305:Dose-Response Relationship, Drug; D015180:Electrophoresis, Gel, Two-Dimensional; D020869:Gene Expression Profiling; D050883:HSC70 Heat-Shock Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000652:urine*; D006801:Humans; D007553:Isotope Labeling; D007668:Kidney / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D008297:Male; D010751:Phosphopyruvate Hydratase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000652:urine*; D040901:Proteomics / Q000379:methods; D017207:Rats, Sprague-Dawley; D051437:Renal Insufficiency / Q000209:etiology*; D021241:Spectrometry, Mass, Electrospray Ionization; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D015854:Up-Regulation / Q000187:drug effects*
chemical_list: D015415:Biomarkers; D050883:HSC70 Heat-Shock Proteins; C494373:Hspa8 protein, rat; C000609763:ENO1 protein, rat; D010751:Phosphopyruvate Hydratase; D019256:Cadmium Chloride
keywords: ENO1; HK-2; HSPA8; biomarkers; conditioned media; nephrotoxicity