Cellular adaptive response of distal renal tubular cells to high-oxalate environment highlights surface alpha-enolase as the enhancer of calcium oxalate monohydrate crystal adhesion.
Hyperoxaluria is one of etiologic factors of calcium oxalate kidney stone disease. However, response of renal tubular cells to high-oxalate environment remained largely unknown. We applied a gel-based proteomics approach to characterize changes in cellular proteome of MDCK cells induced by 10mM sodium oxalate. A total of 14 proteins were detected as differentially expressed proteins. The oxalate-induced up-regulation of alpha-enolase in whole cell lysate was confirmed by 2-D Western blot analysis. Interaction network analysis revealed that cellular adaptive response under high-oxalate condition involved stress response, energy production, metabolism and transcriptional regulation. Down-regulation of RhoA, which was predicted to be associated with the identified proteins, was confirmed by immunoblotting. In addition, the up-regulation of alpha-enolase on apical surface of renal tubular epithelial cells was also confirmed by immunoblotting of the isolated apical membranes and immunofluorescence study. Interestingly, blockage of alpha-enolase expressed on the cell surface by antibody neutralization significantly reduced the number of calcium oxalate monohydrate (COM) crystals adhered on the cells. These results strongly suggest that surface alpha-enolase plays an important role as the enhancer of COM crystal binding. The increase of alpha-enolase expressed on the cell surface may aggravate kidney stone formation in patients with hyperoxaluria.
Medical Proteomics Unit, Office for Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand; Center for Research in Complex Systems Science, Mahidol University, Bangkok, Thailand.
Rattiyaporn
R
Kanlaya
Medical Proteomics Unit, Office for Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand; Center for Research in Complex Systems Science, Mahidol University, Bangkok, Thailand.
Kedsarin
K
Fong-Ngern
Medical Proteomics Unit, Office for Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand; Center for Research in Complex Systems Science, Mahidol University, Bangkok, Thailand. Electronic address: thongboonkerd@dr.com.
Visith
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Thongboonkerd
D000818:Animals; D002129:Calcium Oxalate / Q000737:chemistry*; D002462:Cell Membrane / Q000378:metabolism; D003460:Crystallization; D004285:Dogs; D015536:Down-Regulation; D015180:Electrophoresis, Gel, Two-Dimensional; D006959:Hyperoxaluria / Q000378:metabolism; D007669:Kidney Calculi / Q000378:metabolism; D007684:Kidney Tubules / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D061985:Madin Darby Canine Kidney Cells; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D010070:Oxalates / Q000737:chemistry*; D019815:Oxalic Acid / Q000737:chemistry; D010751:Phosphopyruvate Hydratase / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry; D040901:Proteomics / Q000379:methods; D053719:Tandem Mass Spectrometry; D020742:rhoA GTP-Binding Protein / Q000737:chemistry
D010070:Oxalates; D011506:Proteins; D002129:Calcium Oxalate; D019815:Oxalic Acid; D020742:rhoA GTP-Binding Protein; D010751:Phosphopyruvate Hydratase