2046 EFFECT OF RENAL LIPID ACCUMULATION ON THE EARLY PROCESSES OF KIDNEY STONE FORMATION

Abstract

You have accessJournal of UrologyStone Disease: Basic Research1 Apr 20112046 EFFECT OF RENAL LIPID ACCUMULATION ON THE EARLY PROCESSES OF KIDNEY STONE FORMATION Yasuo Kohjimoto, Yumiko Sasaki, Nagahide Matsumura, Takeshi Inagaki, and Isao Hara Yasuo KohjimotoYasuo Kohjimoto Wakayama, Japan More articles by this author , Yumiko SasakiYumiko Sasaki Wakayama, Japan More articles by this author , Nagahide MatsumuraNagahide Matsumura Wakayama, Japan More articles by this author , Takeshi InagakiTakeshi Inagaki Wakayama, Japan More articles by this author , and Isao HaraIsao Hara Wakayama, Japan More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2011.02.2277AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Although a number of epidemiological studies revealed that metabolic syndrome (MetS) was associated with kidney stone disease, the underlying mechanisms remain unclear. Recent evidence suggests that intracellular lipid accumulation can account for many manifestations of the MetS through cellular dysfunction and injury (lipotoxicity). The present study examined the effect of intracellular accumulation of triglyceride on the early processes of kidney stone formation using cultured renal epithelial cells. METHODS Madin-Darby canine kidney (MDCK) cells were incubated with albumin-bearing oleic acid (OA) or vehicle (albumin). After varying periods of time, intracellular lipid accumulation was assessed by lipid staining with oil red O and triglyceride measurement. This model of cellular lipotoxicity was provided for the following experiments. (1) Oxalate-induced cellular injury: Cells were exposed to 1 mM sodium oxalate in the culture media for 2 hours. The oxidative stress and cytotoxicity were assessed by measuring hydrogen peroxide (H2O2) and lactate dehydrogenase (LDH), respectively. (2) Calcium oxalate monohydrate (COM) crystal adhesion: After pretreatment with 1mM oxalate for 2 hours, cells were exposed to COM crystal at a concentration of 5μg/cm2 for 5 minutes. Quantitative analysis of the adherent crystals was performed by measuring the calcium concentration of the cell lysate. RESULTS Incubation of MDCK cells with OA resulted in dose- and time-dependent intracellular accumulation of triglyceride. Oxalate-induced LDH release was significantly increased in the cells incubated with 0.5 mM and 1 mM OA for 12 hours compared with the cells incubated with vehicle (Figure). Also, oxalate-induced H2O2 generation in these cells was increased significantly, but to a minor extent (3.4–3.9%, p<0.01). COM crystal adhesion to MDCK cells incubated with 1 mM OA was also increased by 24.4 ± 25.1% (p=0.05). CONCLUSIONS The results indicate that lipid accumulation in renal epithelial cells enhances two critical steps in the early processes of kidney stone formation, namely oxalate-induced cellular injury and COM crystal adhesion. Thus, lipotoxicity in renal epithelial cells might account for kidney stone formation in MetS. © 2011 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 185Issue 4SApril 2011Page: e819 Advertisement Copyright & Permissions© 2011 by American Urological Association Education and Research, Inc.MetricsAuthor Information Yasuo Kohjimoto Wakayama, Japan More articles by this author Yumiko Sasaki Wakayama, Japan More articles by this author Nagahide Matsumura Wakayama, Japan More articles by this author Takeshi Inagaki Wakayama, Japan More articles by this author Isao Hara Wakayama, Japan More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...