Cadmium-cardiolipin disruption of respirasome assembly and redox balance through mitochondrial membrane rigidification

作     者：Romanova, Nadiya Sule, Kevin Issler, Travis Hebrok, Daniel Persicke, Marcus Thevenod, Frank Prenner, Elmar J. Lee, Wing-Kee 

作者机构：Bielefeld Univ Med Sch OWL Physiol & Pathophysiol Cells & Membranes Bielefeld Germany Univ Calgary Dept Biol Sci Calgary AB Canada Med Sch OWL Prote & Metabol Core Facil Bielefeld Germany Bielefeld Univ Ctr Biotechnol Microbial Genom & Biotechnol Bielefeld Germany Witten Herdecke Univ Inst Physiol & Pathophysiol ZBAF Witten Germany 

出 版 物：《JOURNAL OF LIPID RESEARCH》 (J. Lipid Res.)

年 卷 期：2025年第66卷第3期

页      面：100750页

核心收录：

学科分类：0710[理学-生物学] 071010[理学-生物化学与分子生物学] 07[理学] 

基　　金：German Research Foundation (Deutsche Forschungsgemeinschaft) [LE2387 8-1, LE2387 9-1] Mitacs Globalink Research Awards NSERC Discovery grant [RGPIN-2024-03950] 

主　　题：heavy metal toxicity reactive oxygen species electron transport chain liquid-ordered phase CI complex I CIII complex III CIV complex IV Cd cadmium CL cardiolipin CRLS1 cardiolipin synthase 1 cyt c cytochrome c DHR123 dihydrorhodamine 123 DMT1 divalent metal transporter 1 DOPE dioleoylphosphatidylethanolamine DPH diphenylhexatriene ETC electron transport chain EV empty vector FDA U.S. Food and Drug Administration GP generalized polarization GSH glutathione (reduced) HPCT human proximal convoluted tubule IB immunoblot IMM inner mitochondrial membrane IMS intermembrane space LUV large unilamellar vesicle MCU mitochondrial calcium uniporter MLV multilamellar vesicle MT metallothionein MTT 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide OML outer membrane leaflet OMM outer mitochondrial membrane PC phosphatidylcholine PE phosphatidylethanolamine PM plasma membrane Rh123 + rhodamine 123 + rKC mito rat kidney cortex mitochondria ROS reactive oxygen species SAPI stearoyl-arachidonoyl-phosphatidylinositol SC supercomplex SFM serum free medium TLCL tetralinoleoyl cardiolipin TMCL tetramyristoyl cardiolipin TOCL tetraoleoyl cardiolipin VDAC voltage dependent anion channel 

摘      要：The environmental pollutant cadmium (Cd) poses a threat to human health through the consumption of contaminated foodstuffs culminating in chronic nephrotoxicity. Mitochondrial dysfunction and excessive reactive oxygen species (ROS) are key to Cd cellular toxicity. Cd-lipid interactions have been less considered. We hypothesized Cd binding to the inner mitochondrial membrane (IMM) phospholipid cardiolipin (CL) and membrane rigidification underlies defective electron transfer by disrupted respiratory supercomplexes (SCs). In Cd-treated rat kidney cortex (rKC) mitoplasts, laurdan (lipid-water interface), and diphenylhexatriene (hydrophobic core) revealed increased and decreased membrane fluidity, respectively. Laurdan-loaded pure CL or IMM biomimetic (40 mol % POPC, 35 mol % DOPE, 20 mol % TOCL, 5 mol % SAPI) nanoliposomes were rigidified by 25 mu M Cd, which was confirmed in live- cell imaging of laurdan or di-4-ANEPPDHQ loaded human proximal convoluted tubule (HPCT) cells. Blue native gel electrophoresis evidenced similar to 30% loss of I+III2+IVn SC formation after 5 mu M Cd for 6 h in HPCTs, which was reversed by CL-binding drug MTP-131/SS-31/elamipretide (0.1 mu M), yet a-tocopherol-insensitive. Moreover, MTP-131 attenuated Cdinduced H2O2 (similar to 30%) and cytochrome c release (similar to 25%), but not osmotic swelling, in rKC mitochondria as well as Cd-induced ROS (similar to 25%) in HPCTs. MTP-131 binding to IMM biomimetic nanoliposomes decreased zeta potential, prevented Cd-induced liposome size increase, and membrane rigidification reported by laurdan. Heterologous CRLS1 expression reversed Cd (5 mu M, 24 h) cytotoxicity (similar to 25%) by MTT assay, Cd (5 mu M, 3 h)-induced ROS and mitochondrial membrane rigidification by Cd (1 mu M, 1 h) in HPCT cells. In summary, we report a novel mechanism for Cd toxicity in which Cd-CL interactions cause IMM rigidification, thereby disrupting correct SC assembly and increasing ROS.