Localization of hydroxynonenal protein adducts in normal human kidney and selected human kidney cancers

Abstract

Both polyclonal and monoclonal antibodies to 4-hydroxy-2-nonenal (HNE) protein adducts were used to identify lipid peroxidation products in normal human kidney and in selected human kidney cancers using immunoperoxidase techniques at the light microscopic level and immunogold techniques at the ultrastructural level. HNE protein adducts were detected in most cell types in normal kidney, although in highly variable amounts. All six morphologic types of renal tumors examined showed some staining with antibodies to HNE protein adducts, although the intensity of staining varied considerably depending on tumor type. Renal oncocytoma and the granular cell variant of renal adenocarcinoma both showed greater cytoplasmic staining for HNE protein adducts than the other tumors examined; these tumors both contain high numbers of mitochondria and suggest that mitochondria are a major source of lipid peroxidation products. To test this possibility, immunogold ultrastructural analysis was performed. HNE protein adducts were identified in nuclei and mitochondria in both normal proximal tubule and three types of renal carcinoma examined; these results localize oxidative damage at the subcellular level in both benign and malignant epithelium to nuclei and mitochondria. In conclusion, HNE protein adducts occur in kidneys in both normal and tumor cells, although immunomorphologic analyses suggest less HNE protein adducts in tumor cells.