title: Role of annexin A5 in cisplatin-induced toxicity in renal cells: molecular mechanism of apoptosis.
abstract: Annexin A5 belongs to a large family of calcium-binding and phospholipid-binding proteins and may act as an endogenous regulator of various pathophysiological processes. There is increasing evidence that annexin A5 is related to cytotoxicity, but the precise function of this protein has yet to be elucidated. In this study, we aimed to verify the function of annexin A5 in the apoptosis of renal epithelial cells. Real-time PCR and Western blot analysis, together with immunofluorescence analysis, showed that the expression of annexin A5 significantly increased in the presence of cisplatin in both human and rat renal epithelial cells. With regard to the mechanism of cisplatin-induced apoptosis, apoptosis-inducing factor (AIF) release into the cytosol was observed, and the underlying mechanism was identified as voltage-dependent anion channel (VDAC) oligomerization. Mitochondrial membrane potential (Δψm) was found to be greatly disrupted in cisplatin-treated cells. Moreover, cisplatin strongly induced translocation of annexin A5 into mitochondria. To understand the functional significance of annexin A5 in renal cell death, we used a siRNA-mediated approach to knock down annexin A5. Annexin A5 depletion by siRNA led to decreased annexin A5 translocation into mitochondria and significantly reduced VDAC oligomerization and AIF release. Annexin A5 siRNA also increased cell viability compared with the control. Moreover, expression of annexin A5 was induced by other nephrotoxicants such as CdCl2 and bacitracin. Taken together, our data suggest that annexin A5 may play a crucial role in cisplatin-induced toxicity by mediating the mitochondrial apoptotic pathway via the induction and oligomerization of VDAC.
authors: From the College of Pharmacy, Chung-Ang University, Seoul 156-756 and.
authors: Jin-Joo
authors: JJ
authors: Jeong
authors: Nahee
authors: N
authors: Park
authors: Yeo-Jung
authors: YJ
authors: Kwon
authors: Dong-Jin
authors: DJ
authors: Ye
authors: Aree
authors: A
authors: Moon
authors: Young-Jin
authors: YJ
authors: Chun
mesh_terms: D000818:Animals; D017304:Annexin A5 / Q000235:genetics / Q000378:metabolism*; D000900:Anti-Bacterial Agents / Q000009:adverse effects / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000009:adverse effects* / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects* / Q000235:genetics; D051033:Apoptosis Inducing Factor / Q000235:genetics / Q000378:metabolism; D001414:Bacitracin / Q000009:adverse effects / Q000494:pharmacology; D019256:Cadmium Chloride / Q000633:toxicity; D002460:Cell Line; D002945:Cisplatin / Q000009:adverse effects* / Q000494:pharmacology; D003600:Cytosol / Q000378:metabolism; D004847:Epithelial Cells / Q000378:metabolism* / Q000473:pathology; D055785:Gene Knockdown Techniques; D006801:Humans; D007687:Kidney Tubules, Proximal / Q000378:metabolism* / Q000473:pathology; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects / Q000235:genetics; D008928:Mitochondria / Q000378:metabolism / Q000473:pathology; D055503:Protein Multimerization / Q000187:drug effects / Q000235:genetics; D021381:Protein Transport / Q000187:drug effects / Q000235:genetics; D051381:Rats; D050994:Voltage-Dependent Anion Channels / Q000235:genetics / Q000378:metabolism
chemical_list: C494829:AIFM1 protein, human; C494831:Aifm1 protein, rat; D017304:Annexin A5; D000900:Anti-Bacterial Agents; D000970:Antineoplastic Agents; D051033:Apoptosis Inducing Factor; D050994:Voltage-Dependent Anion Channels; D001414:Bacitracin; D019256:Cadmium Chloride; D002945:Cisplatin
keywords: Annexin; Annexin A5; Cisplatin; Kidney; Mitochondrial Apoptosis; Nephrotoxicity; Protein Translocation; Renal Epithelial Cell; VDAC; siRNA