Molecular mechanism of Ca2+-induced mitochondrial shape transition in metazoans

Ca2+诱导后生动物线粒体形态转变的分子机制

基本信息

批准号：
10527556
负责人：
MADESH MUNISWAMY
金额：
$ 2.46万
依托单位：
UNIVERSITY OF TEXAS HLTH SCIENCE CENTER
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-08-15 至 2023-11-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10527556
关键词：
Animals Autophagocytosis Binding Biochemical Bioenergetics CRISPR library CRISPR/Cas technology Calcium Calcium Oscillations Cell Death Cell Survival Cell physiology Cells Cessation of life Complex Cytosol Data Disease Dissociation EF-Hand Domain Electron Microscopy Elements Embryo Excision Exhibits Failure Future Genes Glutamates Harvest Hepatocyte Imaging Techniques In Vitro Infarction Investigation Ischemia Kinesin Knock-in Knock-out Knockout Mice Liver Mediating Membrane Potentials Mitochondria Mitochondrial DNA Mitochondrial Matrix Mitochondrial Swelling Modeling Molecular Mus Mutation Necrosis Neurologic Neurons Outer Mitochondrial Membrane Oxidants Oxidation-Reduction Oxidoreductase Permeability Physiology Play Potential Energy Proteins Quality Control Regulation Reperfusion Injury Reperfusion Therapy Resistance Risk Role Second Messenger Systems Shapes Signal Transduction Stress Stroke Testing Toxic effect Tubulin base calcium uniporter cell type cellular pathology deep sequencing experimental study genome wide screen genome-wide indexing loss of function mitochondrial dysfunction mitochondrial permeability transition pore next generation preservation prevent response rho GTP-Binding Proteins sensor spatiotemporal therapeutic development therapeutic target treatment strategy uptake whole genome

项目摘要

PROJECT SUMMARY / ABSTRACT Ca2+ is a critical second messenger that is required for several cellular processes. Cytosolic Ca2+ (cCa2+) transients are shaped by the mitochondria due to the highly negative membrane potential and through the mitochondrial calcium uniporter (MCU). Mitochondrial Ca2+ (mCa2+) is utilized by the matrix dehydrogenases for maintaining cellular bioenergetics. Reciprocally, dysregulated elevation of cCa2+ under conditions of stroke, ischemia/reperfusion injury drives mCa2+ overload that in turn leads to mitochondrial permeability transition pore opening that triggers necrotic cell death. Hence, it was thought that preventing mCa2+ overload can be protective under conditions of elevated cCa2+. Contrary to this, mice knocked-out for MCU, which demonstrated no mCa2+ uptake and hence no mitochondrial swelling, surprisingly did not offer any protection from IR mediated cell death, suggesting that loss of MCU-mediated Ca2+ overload was not sufficient to protect cells from Ca2+-induced necrosis. To understand the molecular mechanisms of elevated Ca2+-induced cell death, we performed ultra-structural analysis of liver harvested from liver specific MCU-/- (MCUHEP) and MCUfl/fl animals. Electron microscopy studies revealed stark contrast in the shape of mitochondria: MCUfl/fl liver sections showed long and filamentous mitochondria (spaghetti-like) while MCUHEP mitochondria were short and circular (donut-like). We hypothesized this Mitochondrial Shape Transition phenomenon that we refer hereafter as MiST, to be cCa2+-induced and independent of mitochondrial swelling or Drp1-mediated mitochondrial fission. Based on our preliminary results, we hypothesize that pathophysiological elevation of cCa2+ induces MiST and that is Miro-1 driven. Because cellular mitochondrial networks allow for the sharing of metabolites, proteins, mitochondrial DNA and potential energy distribution, there is an extensive risk for local mitochondrial failures to quickly spread over the entire network and compromise cellular energy conversion. Like power networks that physically segment elements with circuit breakers, we hypothesize that MiST protects mitochondrial networks from propagating local failures. Our recently completed whole genome-wide CRISPR/Cas9 Library screen in MEFs identified a conserved protein, S100z to be the cytosolic component for MiST. We expect MiST to be a sequential step with a major determinant to be the cCa2+ transients and the molecular component to be shared by the cytosol (S100Z) and the mitochondria (Miro1). We also hypothesize that MiST is likely to be conserved in metazoans and would facilitate lysosomal removal by autophagy/mitophagy depending on the varying cCa2+ transients, thus preserving the quality of the mitochondrial network. The revelation of this Ca2+-induced phenomenon and the identification of the molecular components will resolve the spatio-temporal molecular mechanisms of MiST. Successful accomplishment of our proposed experiments using our cellular, biochemical, and imaging techniques will authentically demonstrate MiST to be key regulator in maintaining mitochondrial quality control under pathophysiological conditions.

项目摘要 /摘要 CA2+是几个蜂窝过程所需的关键第二信使。胞质Ca2+（CCA2+）由于高度负膜电位，瞬态是由线粒体形成的线粒体钙校准蛋白（MCU）。线粒体Ca2+（MCA2+）由基质脱氢酶用于维持细胞生物能学。在中风条件下，CCA2+的升高不足，在中风条件下升高缺血/再灌注损伤驱动MCA2+超负荷，进而导致线粒体通透性过渡孔打开这会触发坏死细胞死亡。因此，人们认为可以防止MCA2+超负荷在CCA2+升高的条件下保护性。与此相反，老鼠为MCU淘汰了，这证明了没有MCA2+摄取，因此没有线粒体肿胀，令人惊讶的是没有提供任何IR的保护介导的细胞死亡，表明MCU介导的Ca2+过载的损失不足以保护细胞来自Ca2+诱导的坏死。要了解Ca2+诱导的细胞死亡的分子机制，我们从肝脏特异性MCU - / - （MCUHEP）和MCUFL/FL动物中对肝脏进行了超结构分析。电子显微镜研究揭示了线粒体形状的鲜明对比：MCUFL/FL肝脏切片显示长而丝状线粒体（意大利面条状），而McUhep线粒体则短而圆形（类似甜甜圈）。我们假设这种线粒体形状过渡现象，我们将其称为雾，是CCA2+诱导的，并且与线粒体肿胀或DRP1介导的线粒体裂变无关。根据我们的初步结果，我们假设CCA2+的病理生理升高会诱导雾气和那就是miro-1驱动。因为细胞线粒体网络允许代谢物，蛋白质共享线粒体DNA和势能分布，局部线粒体失败存在很大的风险迅速分布在整个网络上，并损害细胞能量转换。像电力网络带有断路器的物理细分元素，我们假设雾气保护线粒体网络通过传播当地失败。我们最近完成的全基因组CRISPR/CAS9库屏幕 MEF将组成的蛋白质（S100Z）确定为雾的胞质成分。我们希望雾成为主要确定源是CCA2+瞬态和要共享的分子成分的顺序步骤由细胞质（S100Z）和线粒体（MIRO1）。我们还假设雾气可能是保存的在后生动物中，将促进自噬/线粒体的溶酶体去除，具体取决于不同的CCA2+ 瞬态，从而保留线粒体网络的质量。此CA2+诱导的开发现象和分子成分的鉴定将解决空间分子雾的机理。成功实现了我们提出的实验，使用我们的细胞生化和成像技术将真实地证明雾为维护的关键调节剂病理生理条件下的线粒体质量控制。

项目成果

期刊论文数量（39）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Emergence of repurposed drugs as modulators of MCU channel for clinical therapeutics.

重新利用药物作为临床治疗的 MCU 通道调节剂的出现。

DOI：
10.1016/j.ceca.2021.102456
发表时间：
2021
期刊：
Cell calcium
影响因子：
4
作者：
Vishnu,Neelanjan;Wilson,Justin;Madesh,Muniswamy
通讯作者：
Madesh,Muniswamy

The Mitochondrial Calcium Uniporter Matches Energetic Supply with Cardiac Workload during Stress and Modulates Permeability Transition.

DOI：
10.1016/j.celrep.2015.06.017
发表时间：
2015-07-07
期刊：
Cell reports
影响因子：
8.8
作者：
Luongo TS;Lambert JP;Yuan A;Zhang X;Gross P;Song J;Shanmughapriya S;Gao E;Jain M;Houser SR;Koch WJ;Cheung JY;Madesh M;Elrod JW
通讯作者：
Elrod JW

SPG7 Is an Essential and Conserved Component of the Mitochondrial Permeability Transition Pore.

DOI：
10.1016/j.molcel.2015.08.009
发表时间：
2015-10-01
期刊：
Molecular cell
影响因子：
16
作者：
Shanmughapriya S;Rajan S;Hoffman NE;Higgins AM;Tomar D;Nemani N;Hines KJ;Smith DJ;Eguchi A;Vallem S;Shaikh F;Cheung M;Leonard NJ;Stolakis RS;Wolfers MP;Ibetti J;Chuprun JK;Jog NR;Houser SR;Koch WJ;Elrod JW;Madesh M
通讯作者：
Madesh M

Ca2+ signals regulate mitochondrial metabolism by stimulating CREB-mediated expression of the mitochondrial Ca2+ uniporter gene MCU.

DOI：
10.1126/scisignal.2005673
发表时间：
2015-03-03
期刊：
Science signaling
影响因子：
7.3
作者：
Shanmughapriya S;Rajan S;Hoffman NE;Zhang X;Guo S;Kolesar JE;Hines KJ;Ragheb J;Jog NR;Caricchio R;Baba Y;Zhou Y;Kaufman BA;Cheung JY;Kurosaki T;Gill DL;Madesh M
通讯作者：
Madesh M

pH-Sensitive Multiligand Gold Nanoplatform Targeting Carbonic Anhydrase IX Enhances the Delivery of Doxorubicin to Hypoxic Tumor Spheroids and Overcomes the Hypoxia-Induced Chemoresistance.