Role of cytochrome P450 2B1 in puromycin aminonucleoside-induced cytotoxicity to glomerular epithelial cells.
Puromycin aminonucleoside (PAN)-induced glomerular injury in rats mimics minimal-change nephrotic syndrome (NS) in humans. We have demonstrated an important role of cytochrome P450 (CYP) as a significant source of catalytic iron in this model of NS. The current study was designed to identify CYP isozyme(s) present in the rat glomerular epithelial cells (GEC) and to explore the role of the specific CYP isozyme in PAN-induced cytotoxicity. CYP2B1 was identified in GEC by immunocytochemistry and Western blot. Treatment of GEC with PAN resulted in a marked generation of hydrogen peroxide (H(2)O(2)) and reduction of CYP2B1 content associated with significant increase in catalytic iron and hydroxyl radical formation. Preincubating GEC with CYP2B1 inhibitors (piperine and cimetidine) and H(2)O(2) scavenger (pyruvate) significantly reduced H(2)O(2 )generation, preserved CYP2B1 content, prevented the increase in catalytic iron and hydroxyl radical formation including PAN-induced cytotoxicity. We also observed the induction of heme oxygenase (HO-1) in PAN-treated GEC, and this up-regulation was reduced by pretreatment of the CYP inhibitors and pyruvate. Our data thus indicate an important role of CYP2B1 in PAN-induced cytotoxicity by serving as a site of reactive oxygen metabolite generation and a significant source of catalytic iron.
Liu
Hua
H
Department of Pediatrics, University of Mississippi Medical Center, Jackson 39216-4505, USA.
Baliga
Mithra
M
Bigler
Steven A
SA
Baliga
Radhakrishna
R
D000818:Animals; D002478:Cells, Cultured; D002927:Cimetidine / Q000494:pharmacology; D019362:Cytochrome P-450 CYP2B1 / Q000037:antagonists & inhibitors / Q000502:physiology*; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004790:Enzyme Induction / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004847:Epithelial Cells / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology; D006419:Heme Oxygenase (Decyclizing) / Q000378:metabolism; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D007150:Immunohistochemistry; D007674:Kidney Diseases / Q000139:chemically induced* / Q000201:enzymology / Q000473:pathology; D007678:Kidney Glomerulus / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology; D009404:Nephrotic Syndrome / Q000201:enzymology / Q000473:pathology; D010865:Pilot Projects; D011692:Puromycin Aminonucleoside / Q000009:adverse effects*; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism; D013997:Time Factors
D004791:Enzyme Inhibitors; D017382:Reactive Oxygen Species; D011692:Puromycin Aminonucleoside; D002927:Cimetidine; D006861:Hydrogen Peroxide; D019362:Cytochrome P-450 CYP2B1; D006419:Heme Oxygenase (Decyclizing)