1
|
Savoca M, Takemoto K, Hu J, Li L, Jacob Kendrick B, Zhong Z, Lemasters JJ. MitoTracker Red for isolation of zone-specific hepatocytes and characterization of hepatic sublobular metabolism. Biochem Biophys Res Commun 2024; 735:150457. [PMID: 39146811 DOI: 10.1016/j.bbrc.2024.150457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2024] [Revised: 07/22/2024] [Accepted: 07/25/2024] [Indexed: 08/17/2024]
Abstract
BACKGROUND The liver lobule is divided into three zones or regions: periportal (PP or Zone 1) that is highly oxidative and active in ureagenesis, pericentral (PC or Zone 3) that is more glycolytic, and midzonal (MZ or Zone 2) with intermediate characteristics. AIM Our goal was to isolate and metabolically characterize hepatocytes from specific sublobular zones. METHODS Mice were administered rhodamine123 (Rh123) or MitoTracker Red (MTR) prior to intravital imaging, liver fixation, or hepatocyte isolation. After in vivo MTR, hepatocytes were isolated and sorted based on MTR fluorescence intensity. Alternatively, E-cadherin (Ecad) and cytochrome P450 2E1 (CYP2E1) immunolabeling was performed in fixed liver slices. Ecad and CYP2E1 gene expression in sorted hepatocytes was assessed by qPCR. Oxygen consumption rates (OCR) of sorted hepatocytes were also assessed. RESULTS Multiphoton microscopy showed Rh123 and MTR fluorescence distributed zonally, decreasing from PP to PC in a flow-dependent fashion. In liver cross-sections, Ecad was expressed periportally and CYP2E1 pericentrally in association with high and low MTR labeling, respectively. Based on MTR fluorescence, hepatocytes were sorted into PP, MZ, and PC populations with PP and PC hepatocytes enriched in Ecad and CYP2E1, respectively. OCR of PP hepatocytes was ∼4 times that of PC hepatocytes. CONCLUSIONS MTR treatment in vivo delineates sublobular hepatic zones and can be used to sort hepatocytes zonally. PP hepatocytes have substantially greater OCR compared to PC and MZ. The results also indicate a sharp midzonal demarcation between hepatocytes with PP characteristics (Ecad) and those with PC features (CYP2E1). This new method to sort hepatocytes in a zone-specific fashion holds the potential to shed light on sublobular hepatocyte metabolism and regulatory pathways in health and disease.
Collapse
Affiliation(s)
- Matthew Savoca
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Kenji Takemoto
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Jiangting Hu
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Li Li
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC 29425, USA
| | - B Jacob Kendrick
- Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA; Darby Children's Research Institute, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Zhi Zhong
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC 29425, USA
| | - John J Lemasters
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC 29425, USA; Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA; Department of Biochemistry & Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA.
| |
Collapse
|
2
|
Desai S, Grefte S, van de Westerlo E, Lauwen S, Paters A, Prehn JHM, Gan Z, Keijer J, Adjobo-Hermans MJW, Koopman WJH. Performance of TMRM and Mitotrackers in mitochondrial morphofunctional analysis of primary human skin fibroblasts. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2024; 1865:149027. [PMID: 38109971 DOI: 10.1016/j.bbabio.2023.149027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 10/30/2023] [Accepted: 12/04/2023] [Indexed: 12/20/2023]
Abstract
Mitochondrial membrane potential (Δψ) and morphology are considered key readouts of mitochondrial functional state. This morphofunction can be studied using fluorescent dyes ("probes") like tetramethylrhodamine methyl ester (TMRM) and Mitotrackers (MTs). Although these dyes are broadly used, information comparing their performance in mitochondrial morphology quantification and Δψ-sensitivity in the same cell model is still scarce. Here we applied epifluorescence microscopy of primary human skin fibroblasts to evaluate TMRM, Mitotracker Red CMXros (CMXros), Mitotracker Red CMH2Xros (CMH2Xros), Mitotracker Green FM (MG) and Mitotracker Deep Red FM (MDR). All probes were suited for automated quantification of mitochondrial morphology parameters when Δψ was normal, although they did not deliver quantitatively identical results. The mitochondrial localization of TMRM and MTs was differentially sensitive to carbonyl cyanide-4-phenylhydrazone (FCCP)-induced Δψ depolarization, decreasing in the order: TMRM ≫ CHM2Xros = CMXros = MDR > MG. To study the effect of reversible Δψ changes, the impact of photo-induced Δψ "flickering" was studied in cells co-stained with TMRM and MG. During a flickering event, individual mitochondria displayed subsequent TMRM release and uptake, whereas this phenomenon was not observed for MG. Spatiotemporal and computational analysis of the flickering event provided evidence that TMRM redistributes between adjacent mitochondria by a mechanism dependent on Δψ and TMRM concentration. In summary, this study demonstrates that: (1) TMRM and MTs are suited for automated mitochondrial morphology quantification, (2) numerical data obtained with different probes is not identical, and (3) all probes are sensitive to FCCP-induced Δψ depolarization, with TMRM and MG displaying the highest and lowest sensitivity, respectively. We conclude that TMRM is better suited for integrated analysis of Δψ and mitochondrial morphology than the tested MTs under conditions that Δψ is not substantially depolarized.
Collapse
Affiliation(s)
- Shruti Desai
- Department of Medical BioSciences, Radboud Center for Mitochondrial Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Sander Grefte
- Department of Physiology and Medical Physics and SFI FutureNeuro Centre, RCSI University of Medicine and Health Sciences, Dublin 2, Ireland
| | - Els van de Westerlo
- Department of Medical BioSciences, Radboud Center for Mitochondrial Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Susette Lauwen
- Department of Medical BioSciences, Radboud Center for Mitochondrial Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Angela Paters
- Department of Medical BioSciences, Radboud Center for Mitochondrial Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Jochen H M Prehn
- Department of Physiology and Medical Physics and SFI FutureNeuro Centre, RCSI University of Medicine and Health Sciences, Dublin 2, Ireland
| | - Zhuohui Gan
- Human and Animal Physiology, Wageningen University & Research, Wageningen, the Netherlands
| | - Jaap Keijer
- Human and Animal Physiology, Wageningen University & Research, Wageningen, the Netherlands
| | - Merel J W Adjobo-Hermans
- Department of Medical BioSciences, Radboud Center for Mitochondrial Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Werner J H Koopman
- Human and Animal Physiology, Wageningen University & Research, Wageningen, the Netherlands; Department of Pediatrics, Amalia Children's Hospital, Radboud Center for Mitochondrial Medicine, Radboud University Medical Center, Nijmegen, the Netherlands.
| |
Collapse
|
3
|
Chan SJW, Zhu JY, Mia Soh WW, Bazan GC. Real-Time Monitoring of Mitochondrial Damage Using Conjugated Oligoelectrolytes. J Am Chem Soc 2024; 146:660-667. [PMID: 38131111 DOI: 10.1021/jacs.3c10531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2023]
Abstract
Conjugated oligoelectrolytes (COEs) comprise a class of fluorescent reporters with tunable optical properties and lipid bilayer affinity. These molecules have proven effective in a range of bioimaging applications; however, their use in characterizing specific subcellular structures remains restricted. Such capabilities would broaden COE applications to understand cellular dysfunction, cell communication, and the targets of different pharmaceutical agents. Here, we disclose a novel COE derivative, COE-CN, which enables the visualization of mitochondria, including morphological changes and lysosomal fusion upon treatment with depolarizing agents. COE-CN is characterized by the presence of imidazolium solubilizing groups and an optically active cyanovinyl-linked distyrylbenzene core with intramolecular charge-transfer characteristics. Our current understanding is that the relatively shorter molecular length of COE-CN leads to weaker binding within lipid bilayer membranes, which allows sampling of internal cellular structures and ultimately to different localization relative to elongated COEs. As a means of practical demonstration, COE-CN can be used to diagnose cells with damaged mitochondria via flow cytometry. Coupled with an elongated COE that does not translocate upon depolarization, changes in ratiometric fluorescence intensity can be used to monitor mitochondrial membrane potential disruption, demonstrating the potential for use in diagnostic assays.
Collapse
Affiliation(s)
- Samuel J W Chan
- Department of Chemistry, National University of Singapore, Singapore 117543, Singapore
| | - Ji-Yu Zhu
- Department of Chemistry, National University of Singapore, Singapore 117543, Singapore
| | - Wilson Wee Mia Soh
- Department of Chemistry, National University of Singapore, Singapore 117543, Singapore
| | - Guillermo C Bazan
- Department of Chemistry, National University of Singapore, Singapore 117543, Singapore
- Institute for Functional Intelligent Materials, National University of Singapore, Singapore 117544, Singapore
- Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore 117585, Singapore
| |
Collapse
|
4
|
Hu J, Nieminen AL, Weemhoff JL, Jaeschke H, Murphy LG, Dent JA, Lemasters JJ. The mitochondrial calcium uniporter mediates mitochondrial Fe 2+ uptake and hepatotoxicity after acetaminophen. Toxicol Appl Pharmacol 2023; 479:116722. [PMID: 37848124 PMCID: PMC10872750 DOI: 10.1016/j.taap.2023.116722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 09/23/2023] [Accepted: 10/11/2023] [Indexed: 10/19/2023]
Abstract
Acetaminophen (APAP) overdose disrupts hepatocellular lysosomes, which release ferrous iron (Fe2+) that translocates into mitochondria putatively via the mitochondrial calcium uniporter (MCU) to induce oxidative/nitrative stress, the mitochondrial permeability transition (MPT), and hepatotoxicity. To investigate how MCU deficiency affects mitochondrial Fe2+ uptake and hepatotoxicity after APAP overdose, global MCU knockout (KO), hepatocyte specific (hs) MCU KO, and wildtype (WT) mice were treated with an overdose of APAP both in vivo and in vitro. Compared to strain-specific WT mice, serum ALT decreased by 88 and 56%, respectively, in global and hsMCU KO mice at 24 h after APAP (300 mg/kg). Hepatic necrosis also decreased by 84 and 56%. By contrast, when MCU was knocked out in Kupffer cells, ALT release and necrosis were unchanged after overdose APAP. Intravital multiphoton microscopy confirmed loss of viability and mitochondrial depolarization in pericentral hepatocytes of WT mice, which was decreased in MCU KO mice. CYP2E1 expression, hepatic APAP-protein adduct formation, and JNK activation revealed that APAP metabolism was equivalent between WT and MCU KO mice. In cultured hepatocytes after APAP, loss of cell viability decreased in hsMCU KO compared to WT hepatocytes. Using fructose plus glycine to prevent cell killing, mitochondrial Fe2+ increased progressively after APAP, as revealed with mitoferrofluor (MFF), a mitochondrial Fe2+ indicator. By contrast in hsMCU KO hepatocytes, mitochondrial Fe2+ uptake after APAP was suppressed. Rhod-2 measurements showed that Ca2+ did not increase in mitochondria after APAP in either WT or KO hepatocytes. In conclusion, MCU mediates uptake of Fe2+ into mitochondria after APAP and plays a central role in mitochondrial depolarization and cell death during APAP-induced hepatotoxicity.
Collapse
Affiliation(s)
- Jiangting Hu
- Center for Cell Death, Injury & Regeneration, Medical University of South Carolina, Charleston, SC, United States of America; Departments of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, United States of America
| | - Anna-Liisa Nieminen
- Center for Cell Death, Injury & Regeneration, Medical University of South Carolina, Charleston, SC, United States of America; Departments of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, United States of America; Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, United States of America
| | - James L Weemhoff
- Department of Pharmacology, Toxicology & Therapeutics, University of Kansas Medical Center, Kansas City, KS, United States of America
| | - Hartmut Jaeschke
- Department of Pharmacology, Toxicology & Therapeutics, University of Kansas Medical Center, Kansas City, KS, United States of America
| | - Laura G Murphy
- Center for Cell Death, Injury & Regeneration, Medical University of South Carolina, Charleston, SC, United States of America; Departments of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, United States of America
| | - Judith A Dent
- Center for Cell Death, Injury & Regeneration, Medical University of South Carolina, Charleston, SC, United States of America; Departments of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, United States of America
| | - John J Lemasters
- Center for Cell Death, Injury & Regeneration, Medical University of South Carolina, Charleston, SC, United States of America; Departments of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, United States of America; Biochemistry & Molecular Biology, Medical University of South Carolina, Charleston, SC, United States of America; Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, United States of America.
| |
Collapse
|
5
|
Ashok D, Papanicolaou K, Sidor A, Wang M, Solhjoo S, Liu T, O'Rourke B. Mitochondrial membrane potential instability on reperfusion after ischemia does not depend on mitochondrial Ca 2+ uptake. J Biol Chem 2023; 299:104708. [PMID: 37061004 PMCID: PMC10206190 DOI: 10.1016/j.jbc.2023.104708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 03/21/2023] [Accepted: 04/09/2023] [Indexed: 04/17/2023] Open
Abstract
Physiologic Ca2+ entry via the Mitochondrial Calcium Uniporter (MCU) participates in energetic adaption to workload but may also contribute to cell death during ischemia/reperfusion (I/R) injury. The MCU has been identified as the primary mode of Ca2+ import into mitochondria. Several groups have tested the hypothesis that Ca2+ import via MCU is detrimental during I/R injury using genetically-engineered mouse models, yet the results from these studies are inconclusive. Furthermore, mitochondria exhibit unstable or oscillatory membrane potentials (ΔΨm) when subjected to stress, such as during I/R, but it is unclear if the primary trigger is an excess influx of mitochondrial Ca2+ (mCa2+), reactive oxygen species (ROS) accumulation, or other factors. Here, we critically examine whether MCU-mediated mitochondrial Ca2+ uptake during I/R is involved in ΔΨm instability, or sustained mitochondrial depolarization, during reperfusion by acutely knocking out MCU in neonatal mouse ventricular myocyte (NMVM) monolayers subjected to simulated I/R. Unexpectedly, we find that MCU knockout does not significantly alter mCa2+ import during I/R, nor does it affect ΔΨm recovery during reperfusion. In contrast, blocking the mitochondrial sodium-calcium exchanger (mNCE) suppressed the mCa2+ increase during Ischemia but did not affect ΔΨm recovery or the frequency of ΔΨm oscillations during reperfusion, indicating that mitochondrial ΔΨm instability on reperfusion is not triggered by mCa2+. Interestingly, inhibition of mitochondrial electron transport or supplementation with antioxidants stabilized I/R-induced ΔΨm oscillations. The findings are consistent with mCa2+ overload being mediated by reverse-mode mNCE activity and supporting ROS-induced ROS release as the primary trigger of ΔΨm instability during reperfusion injury.
Collapse
Affiliation(s)
- Deepthi Ashok
- Johns Hopkins University, Division of Cardiology, Department of Medicine, Baltimore, Maryland, USA
| | - Kyriakos Papanicolaou
- Johns Hopkins University, Division of Cardiology, Department of Medicine, Baltimore, Maryland, USA
| | - Agnieszka Sidor
- Johns Hopkins University, Division of Cardiology, Department of Medicine, Baltimore, Maryland, USA
| | - Michelle Wang
- Johns Hopkins University, Division of Cardiology, Department of Medicine, Baltimore, Maryland, USA
| | - Soroosh Solhjoo
- Johns Hopkins University, Division of Cardiology, Department of Medicine, Baltimore, Maryland, USA
| | - Ting Liu
- Johns Hopkins University, Division of Cardiology, Department of Medicine, Baltimore, Maryland, USA
| | - Brian O'Rourke
- Johns Hopkins University, Division of Cardiology, Department of Medicine, Baltimore, Maryland, USA.
| |
Collapse
|
6
|
Rickard BP, Overchuk M, Chappell VA, Kemal Ruhi M, Sinawang PD, Nguyen Hoang TT, Akin D, Demirci U, Franco W, Fenton SE, Santos JH, Rizvi I. Methods to Evaluate Changes in Mitochondrial Structure and Function in Cancer. Cancers (Basel) 2023; 15:2564. [PMID: 37174030 PMCID: PMC10177605 DOI: 10.3390/cancers15092564] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 04/25/2023] [Accepted: 04/26/2023] [Indexed: 05/15/2023] Open
Abstract
Mitochondria are regulators of key cellular processes, including energy production and redox homeostasis. Mitochondrial dysfunction is associated with various human diseases, including cancer. Importantly, both structural and functional changes can alter mitochondrial function. Morphologic and quantifiable changes in mitochondria can affect their function and contribute to disease. Structural mitochondrial changes include alterations in cristae morphology, mitochondrial DNA integrity and quantity, and dynamics, such as fission and fusion. Functional parameters related to mitochondrial biology include the production of reactive oxygen species, bioenergetic capacity, calcium retention, and membrane potential. Although these parameters can occur independently of one another, changes in mitochondrial structure and function are often interrelated. Thus, evaluating changes in both mitochondrial structure and function is crucial to understanding the molecular events involved in disease onset and progression. This review focuses on the relationship between alterations in mitochondrial structure and function and cancer, with a particular emphasis on gynecologic malignancies. Selecting methods with tractable parameters may be critical to identifying and targeting mitochondria-related therapeutic options. Methods to measure changes in mitochondrial structure and function, with the associated benefits and limitations, are summarized.
Collapse
Affiliation(s)
- Brittany P. Rickard
- Curriculum in Toxicology & Environmental Medicine, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Marta Overchuk
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC, and North Carolina State University, Raleigh, NC 27695, USA
| | - Vesna A. Chappell
- Mechanistic Toxicology Branch, Division of Translational Toxicology, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - Mustafa Kemal Ruhi
- Institute of Biomedical Engineering, Boğaziçi University, Istanbul 34684, Turkey
| | - Prima Dewi Sinawang
- Canary Center at Stanford for Cancer Early Detection, Department of Radiology, School of Medicine, Palo Alto, CA 94304, USA
- Department of Chemical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Tina Thuy Nguyen Hoang
- Department of Biomedical Engineering, University of Massachusetts Lowell, Lowell, MA 01854, USA
| | - Demir Akin
- Canary Center at Stanford for Cancer Early Detection, Department of Radiology, School of Medicine, Palo Alto, CA 94304, USA
- Center for Cancer Nanotechnology Excellence for Translational Diagnostics (CCNE-TD), School of Medicine, Stanford University, Stanford, CA 94305, USA
| | - Utkan Demirci
- Canary Center at Stanford for Cancer Early Detection, Department of Radiology, School of Medicine, Palo Alto, CA 94304, USA
| | - Walfre Franco
- Department of Biomedical Engineering, University of Massachusetts Lowell, Lowell, MA 01854, USA
| | - Suzanne E. Fenton
- Mechanistic Toxicology Branch, Division of Translational Toxicology, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - Janine H. Santos
- Mechanistic Toxicology Branch, Division of Translational Toxicology, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - Imran Rizvi
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC, and North Carolina State University, Raleigh, NC 27695, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
- Center for Environmental Health and Susceptibility, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| |
Collapse
|
7
|
Ahmad F, Ramamorthy S, Areeshi MY, Ashraf GM, Haque S. Isolated Mitochondrial Preparations and In organello Assays: A Powerful and Relevant Ex vivo Tool for Assessment of Brain (Patho)physiology. Curr Neuropharmacol 2023; 21:1433-1449. [PMID: 36872352 PMCID: PMC10324330 DOI: 10.2174/1570159x21666230303123555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 10/30/2022] [Accepted: 12/29/2022] [Indexed: 03/07/2023] Open
Abstract
Mitochondria regulate multiple aspects of neuronal development, physiology, plasticity, and pathology through their regulatory roles in bioenergetic, calcium, redox, and cell survival/death signalling. While several reviews have addressed these different aspects, a comprehensive discussion focussing on the relevance of isolated brain mitochondria and their utilities in neuroscience research has been lacking. This is relevant because the employment of isolated mitochondria rather than their in situ functional evaluation, offers definitive evidence of organelle-specificity, negating the interference from extra mitochondrial cellular factors/signals. This mini-review was designed primarily to explore the commonly employed in organello analytical assays for the assessment of mitochondrial physiology and its dysfunction, with a particular focus on neuroscience research. The authors briefly discuss the methodologies for biochemical isolation of mitochondria, their quality assessment, and cryopreservation. Further, the review attempts to accumulate the key biochemical protocols for in organello assessment of a multitude of mitochondrial functions critical for neurophysiology, including assays for bioenergetic activity, calcium and redox homeostasis, and mitochondrial protein translation. The purpose of this review is not to examine each and every method or study related to the functional assessment of isolated brain mitochondria, but rather to assemble the commonly used protocols of in organello mitochondrial research in a single publication. The hope is that this review will provide a suitable platform aiding neuroscientists to choose and apply the required protocols and tools to address their particular mechanistic, diagnostic, or therapeutic question dealing within the confines of the research area of mitochondrial patho-physiology in the neuronal perspective.
Collapse
Affiliation(s)
- Faraz Ahmad
- Department of Biotechnology, School of Bio Sciences and Technology (SBST), Vellore Institute of Technology, Vellore, 632014, India
| | - Siva Ramamorthy
- Department of Biotechnology, School of Bio Sciences and Technology (SBST), Vellore Institute of Technology, Vellore, 632014, India
| | - Mohammed Y. Areeshi
- Medical Laboratory Technology Department, College of Applied Medical Sciences, Jazan University, Jazan, 45142, Saudi Arabia
- Research and Scientific Studies Unit, College of Nursing and Allied Health Sciences, Jazan University, Jazan, 45142, Saudi Arabia
| | - Ghulam Md. Ashraf
- Department of Medical Laboratory Sciences, College of Health Sciences, and Sharjah Institute for Medical Research, University of Sharjah, Sharjah, 27272, United Arab Emirates
| | - Shafiul Haque
- Research and Scientific Studies Unit, College of Nursing and Allied Health Sciences, Jazan University, Jazan, 45142, Saudi Arabia
- Gilbert and Rose-Marie Chagoury School of Medicine, Lebanese American University, Beirut, Lebanon
- Centre of Medical and Bio-Allied Health Sciences Research, Ajman University, Ajman, United Arab Emirates
| |
Collapse
|
8
|
Klier PEZ, Roo R, Miller EW. Fluorescent indicators for imaging membrane potential of organelles. Curr Opin Chem Biol 2022; 71:102203. [PMID: 36084425 PMCID: PMC10259174 DOI: 10.1016/j.cbpa.2022.102203] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 07/18/2022] [Accepted: 07/21/2022] [Indexed: 01/27/2023]
Abstract
Plasma membrane potential is a key driver of the physiology of excitable cells like neurons and cardiomyocytes. Voltage-sensitive fluorescent indicators offer a powerful complement to traditional electrode-based approaches to measuring and monitoring membrane potential. Intracellular organelles can also generate membrane potential, yet the electrode- and fluorescent indicator-based approaches used for plasma membrane potential imaging are difficult to implement on intact organelles in their native environment. Here, we survey recent advances in developing and deploying voltage-sensitive fluorescent indicators to interrogate organelle membrane potential in intact cells.
Collapse
Affiliation(s)
- Pavel E Z Klier
- Department of Chemistry, University of California, Berkeley, CA, 94720, USA
| | - Ryan Roo
- Department of Chemistry, University of California, Berkeley, CA, 94720, USA
| | - Evan W Miller
- Department of Chemistry, University of California, Berkeley, CA, 94720, USA; Department of Molecular & Cell Biology, University of California, Berkeley, CA, 94720, USA; Helen Wills Neuroscience Institute, University of California, Berkeley, CA, 94720, USA.
| |
Collapse
|
9
|
Samuvel DJ, Li L, Krishnasamy Y, Gooz M, Takemoto K, Woster PM, Lemasters JJ, Zhong Z. Mitochondrial depolarization after acute ethanol treatment drives mitophagy in living mice. Autophagy 2022; 18:2671-2685. [PMID: 35293288 PMCID: PMC9629059 DOI: 10.1080/15548627.2022.2046457] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 02/18/2022] [Accepted: 02/22/2022] [Indexed: 12/15/2022] Open
Abstract
Ethanol increases hepatic mitophagy driven by unknown mechanisms. Type 1 mitophagy sequesters polarized mitochondria for nutrient recovery and cytoplasmic remodeling. In Type 2, mitochondrial depolarization (mtDepo) initiates mitophagy to remove the damaged organelles. Previously, we showed that acute ethanol administration produces reversible hepatic mtDepo. Here, we tested the hypothesis that ethanol-induced mtDepo initiates Type 2 mitophagy. GFP-LC3 transgenic mice were gavaged with ethanol (2-6 g/kg) with and without pre-treatment with agents that decrease or increase mtDepo-Alda-1, tacrolimus, or disulfiram. Without ethanol, virtually all hepatocytes contained polarized mitochondria with infrequent autophagic GFP-LC3 puncta visualized by intravital microscopy. At ~4 h after ethanol treatment, mtDepo occurred in an all-or-none fashion within individual hepatocytes, which increased dose dependently. GFP-LC3 puncta increased in parallel, predominantly in hepatocytes with mtDepo. Mitochondrial PINK1 and PRKN/parkin also increased. After covalent labeling of mitochondria with MitoTracker Red (MTR), GFP-LC3 puncta encircled MTR-labeled mitochondria after ethanol treatment, directly demonstrating mitophagy. GFP-LC3 puncta did not associate with fat droplets visualized with BODIPY558/568, indicating that increased autophagy was not due to lipophagy. Before ethanol administration, rhodamine-dextran (RhDex)-labeled lysosomes showed little association with GFP-LC3. After ethanol treatment, TFEB (transcription factor EB) translocated to nuclei, and lysosomal mass increased. Many GFP-LC3 puncta merged with RhDex-labeled lysosomes, showing autophagosomal processing into lysosomes. After ethanol treatment, disulfiram increased, whereas Alda-1 and tacrolimus decreased mtDepo, and mitophagy changed proportionately. In conclusion, mtDepo after acute ethanol treatment induces mitophagic sequestration and subsequent lysosomal processing.Abbreviations : AcAld, acetaldehyde; ADH, alcohol dehydrogenase; ALDH, aldehyde dehydrogenase; ALD, alcoholic liver disease; Alda-1, N-(1,3-benzodioxol-5-ylmethyl)-2,6-dichlorobenzamide; GAPDH, glyceraldehyde-3-phosphate dehydrogenase; GFP, green fluorescent protein; LAMP1, lysosomal-associated membrane protein 1; LMNB1, lamin B1; MAA, malondialdehyde-acetaldehyde adducts; MAP1LC3/LC3, microtubule-associated protein 1 light chain 3; MPT, mitochondrial permeability transition; mtDAMPS, mitochondrial damage-associated molecular patterns; mtDepo, mitochondrial depolarization; mtDNA, mitochondrial DNA; MTR, MitoTracker Red; PI, propidium iodide; PINK1, PTEN induced putative kinase 1; PRKN, parkin; RhDex, rhodamine dextran; TFEB, transcription factor EB; Tg, transgenic; TMRM, tetramethylrhodamine methylester; TOMM20, translocase of outer mitochondrial membrane 20; VDAC, voltage-dependent anion channel.
Collapse
Affiliation(s)
- Devadoss J. Samuvel
- Departments of Drug Discovery & Biomedical Science, Medical University of South Carolin, Charleston, SC, USA
| | - Li Li
- Departments of Drug Discovery & Biomedical Science, Medical University of South Carolin, Charleston, SC, USA
| | - Yasodha Krishnasamy
- Departments of Drug Discovery & Biomedical Science, Medical University of South Carolin, Charleston, SC, USA
| | - Monika Gooz
- Departments of Drug Discovery & Biomedical Science, Medical University of South Carolin, Charleston, SC, USA
| | - Kenji Takemoto
- Departments of Drug Discovery & Biomedical Science, Medical University of South Carolin, Charleston, SC, USA
| | - Patrick M. Woster
- Departments of Drug Discovery & Biomedical Science, Medical University of South Carolin, Charleston, SC, USA
| | - John J. Lemasters
- Departments of Drug Discovery & Biomedical Science, Medical University of South Carolin, Charleston, SC, USA
- Department of Biochemistry & Molecular Biology, Medical University of South Carolina, Charleston, SC, USA
| | - Zhi Zhong
- Departments of Drug Discovery & Biomedical Science, Medical University of South Carolin, Charleston, SC, USA
| |
Collapse
|
10
|
Gottschalk B, Koshenov Z, Waldeck-Weiermair M, Radulović S, Oflaz FE, Hirtl M, Bachkoenig OA, Leitinger G, Malli R, Graier WF. MICU1 controls spatial membrane potential gradients and guides Ca 2+ fluxes within mitochondrial substructures. Commun Biol 2022; 5:649. [PMID: 35778442 PMCID: PMC9249747 DOI: 10.1038/s42003-022-03606-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 06/17/2022] [Indexed: 01/19/2023] Open
Abstract
Mitochondrial ultrastructure represents a pinnacle of form and function, with the inner mitochondrial membrane (IMM) forming isolated pockets of cristae membrane (CM), separated from the inner-boundary membrane (IBM) by cristae junctions (CJ). Applying structured illumination and electron microscopy, a novel and fundamental function of MICU1 in mediating Ca2+ control over spatial membrane potential gradients (SMPGs) between CM and IMS was identified. We unveiled alterations of SMPGs by transient CJ openings when Ca2+ binds to MICU1 resulting in spatial cristae depolarization. This Ca2+/MICU1-mediated plasticity of the CJ further provides the mechanistic bedrock of the biphasic mitochondrial Ca2+ uptake kinetics via the mitochondrial Ca2+ uniporter (MCU) during intracellular Ca2+ release: Initially, high Ca2+ opens CJ via Ca2+/MICU1 and allows instant Ca2+ uptake across the CM through constantly active MCU. Second, MCU disseminates into the IBM, thus establishing Ca2+ uptake across the IBM that circumvents the CM. Under the condition of MICU1 methylation by PRMT1 in aging or cancer, UCP2 that binds to methylated MICU1 destabilizes CJ, disrupts SMPGs, and facilitates fast Ca2+ uptake via the CM.
Collapse
Affiliation(s)
- Benjamin Gottschalk
- grid.11598.340000 0000 8988 2476Gottfried Schatz Research Center: Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Zhanat Koshenov
- grid.11598.340000 0000 8988 2476Gottfried Schatz Research Center: Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Markus Waldeck-Weiermair
- grid.11598.340000 0000 8988 2476Gottfried Schatz Research Center: Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Snježana Radulović
- grid.11598.340000 0000 8988 2476Gottfried Schatz Research Center: Cell Biology, Histology and Embryology, Medical University of Graz, Graz, Austria
| | - Furkan E. Oflaz
- grid.11598.340000 0000 8988 2476Gottfried Schatz Research Center: Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Martin Hirtl
- grid.11598.340000 0000 8988 2476Gottfried Schatz Research Center: Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Olaf A. Bachkoenig
- grid.11598.340000 0000 8988 2476Gottfried Schatz Research Center: Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Gerd Leitinger
- grid.11598.340000 0000 8988 2476Gottfried Schatz Research Center: Cell Biology, Histology and Embryology, Medical University of Graz, Graz, Austria
| | - Roland Malli
- grid.11598.340000 0000 8988 2476Gottfried Schatz Research Center: Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria ,grid.452216.6BioTechMed Graz, Graz, Austria
| | - Wolfgang F. Graier
- grid.11598.340000 0000 8988 2476Gottfried Schatz Research Center: Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria ,grid.452216.6BioTechMed Graz, Graz, Austria
| |
Collapse
|
11
|
Reiche MA, Aaron JS, Boehm U, DeSantis MC, Hobson CM, Khuon S, Lee RM, Chew TL. When light meets biology - how the specimen affects quantitative microscopy. J Cell Sci 2022; 135:274812. [PMID: 35319069 DOI: 10.1242/jcs.259656] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Fluorescence microscopy images should not be treated as perfect representations of biology. Many factors within the biospecimen itself can drastically affect quantitative microscopy data. Whereas some sample-specific considerations, such as photobleaching and autofluorescence, are more commonly discussed, a holistic discussion of sample-related issues (which includes less-routine topics such as quenching, scattering and biological anisotropy) is required to appropriately guide life scientists through the subtleties inherent to bioimaging. Here, we consider how the interplay between light and a sample can cause common experimental pitfalls and unanticipated errors when drawing biological conclusions. Although some of these discrepancies can be minimized or controlled for, others require more pragmatic considerations when interpreting image data. Ultimately, the power lies in the hands of the experimenter. The goal of this Review is therefore to survey how biological samples can skew quantification and interpretation of microscopy data. Furthermore, we offer a perspective on how to manage many of these potential pitfalls.
Collapse
Affiliation(s)
- Michael A Reiche
- Advanced Imaging Center, Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA 20147, USA
| | - Jesse S Aaron
- Advanced Imaging Center, Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA 20147, USA
| | - Ulrike Boehm
- Advanced Imaging Center, Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA 20147, USA
| | - Michael C DeSantis
- Light Microscopy Facility, Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA 20147,USA
| | - Chad M Hobson
- Advanced Imaging Center, Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA 20147, USA
| | - Satya Khuon
- Advanced Imaging Center, Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA 20147, USA.,Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA 20147, USA
| | - Rachel M Lee
- Advanced Imaging Center, Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA 20147, USA
| | - Teng-Leong Chew
- Advanced Imaging Center, Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA 20147, USA.,Light Microscopy Facility, Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA 20147,USA
| |
Collapse
|
12
|
Amemiya T, Yamaguchi T. Oscillations and Dynamic Symbiosis in Cellular Metabolism in Cancer. Front Oncol 2022; 12:783908. [PMID: 35251968 PMCID: PMC8888517 DOI: 10.3389/fonc.2022.783908] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 01/27/2022] [Indexed: 11/23/2022] Open
Abstract
The grade of malignancy differs among cancer cell types, yet it remains the burden of genetic studies to understand the reasons behind this observation. Metabolic studies of cancer, based on the Warburg effect or aerobic glycolysis, have also not provided any clarity. Instead, the significance of oxidative phosphorylation (OXPHOS) has been found to play critical roles in aggressive cancer cells. In this perspective, metabolic symbiosis is addressed as one of the ultimate causes of the grade of cancer malignancy. Metabolic symbiosis gives rise to metabolic heterogeneities which enable cancer cells to acquire greater opportunities for proliferation and metastasis in tumor microenvironments. This study introduces a real-time new imaging technique to visualize metabolic symbiosis between cancer-associated fibroblasts (CAFs) and cancer cells based on the metabolic oscillations in these cells. The causality of cellular oscillations in cancer cells and CAFs, connected through lactate transport, is a key point for the development of this novel technique.
Collapse
Affiliation(s)
- Takashi Amemiya
- Graduate School of Environment and Information Sciences, Yokohama National University (YNU), Yokohama, Japan
- *Correspondence: Takashi Amemiya,
| | - Tomohiko Yamaguchi
- Meiji Institute for Advanced Study of Mathematical Sciences (MIMS), Nakano, Japan
| |
Collapse
|
13
|
Unbiased Millivolts Assay of Mitochondrial Membrane Potential in Intact Cells. Methods Mol Biol 2022; 2497:11-61. [PMID: 35771433 PMCID: PMC9377305 DOI: 10.1007/978-1-0716-2309-1_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The mitochondrial membrane potential (ΔψM) is the major component of the bioenergetic driving force responsible for most cellular ATP produced, and it controls a host of biological processes. In intact cells, assay readouts with commonly used fluorescence ΔψM probes are distorted by factors other than ΔψM. Here, we describe a protocol to calculate both ΔψM and plasma membrane potential (ΔψP) in absolute millivolts in intact single cells, or in populations of adherent, cultured cells. Our approach generates unbiased data that allows comparison of ΔψM between cell types with different geometry and ΔψP, and to follow ΔψM in time when ΔψP fluctuates. The experimental paradigm results in fluorescence microscopy time courses using a pair of cationic and anionic probes with internal calibration points that are subsequently computationally converted to millivolts on an absolute scale. The assay is compatible with wide field, confocal or two-photon microscopy. The method given here is optimized for a multiplexed, partial 96-well microplate format to record ΔψP and ΔψM responses for three consecutive treatment additions.
Collapse
|
14
|
Schmidt CA, Fisher-Wellman KH, Neufer PD. From OCR and ECAR to energy: Perspectives on the design and interpretation of bioenergetics studies. J Biol Chem 2021; 297:101140. [PMID: 34461088 PMCID: PMC8479256 DOI: 10.1016/j.jbc.2021.101140] [Citation(s) in RCA: 71] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 08/25/2021] [Accepted: 08/26/2021] [Indexed: 12/12/2022] Open
Abstract
Biological energy transduction underlies all physiological phenomena in cells. The metabolic systems that support energy transduction have been of great interest due to their association with numerous pathologies including diabetes, cancer, rare genetic diseases, and aberrant cell death. Commercially available bioenergetics technologies (e.g., extracellular flux analysis, high-resolution respirometry, fluorescent dye kits, etc.) have made practical assessment of metabolic parameters widely accessible. This has facilitated an explosion in the number of studies exploring, in particular, the biological implications of oxygen consumption rate (OCR) and substrate level phosphorylation via glycolysis (i.e., via extracellular acidification rate (ECAR)). Though these technologies have demonstrated substantial utility and broad applicability to cell biology research, they are also susceptible to historical assumptions, experimental limitations, and other caveats that have led to premature and/or erroneous interpretations. This review enumerates various important considerations for designing and interpreting cellular and mitochondrial bioenergetics experiments, some common challenges and pitfalls in data interpretation, and some potential "next steps" to be taken that can address these highlighted challenges.
Collapse
Affiliation(s)
- Cameron A Schmidt
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, North Carolina, USA; Departments of Physiology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA
| | - Kelsey H Fisher-Wellman
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, North Carolina, USA; Departments of Physiology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA.
| | - P Darrell Neufer
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, North Carolina, USA; Departments of Physiology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA; Departments of Biochemistry and Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA.
| |
Collapse
|
15
|
Hernández-Juárez C, Flores-Cruz R, Jiménez-Sánchez A. Fluorescent probe for early mitochondrial voltage dynamics. Chem Commun (Camb) 2021; 57:5526-5529. [PMID: 33956917 DOI: 10.1039/d1cc01944a] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Mitochondrial voltage dynamics plays a crucial role in cell healthy and disease. Here, a new fluorescent probe to monitor mitochondrial early voltage variations is described. The slowly permeant probe is retained in mitochondria during measurements to avoid interferences from natural membrane potential by incorporating an hydrolizable ester function. Voltage, local polarity, pH parameters and transmembrane dynamics were found to be deeply correlated opening a approach in mitochondrial sensing.
Collapse
Affiliation(s)
- Cinthia Hernández-Juárez
- Instituto de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, Circuito Exterior s/n, De. Coyoacán 04510, Ciudad de México, Mexico.
| | - Ricardo Flores-Cruz
- Instituto de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, Circuito Exterior s/n, De. Coyoacán 04510, Ciudad de México, Mexico.
| | - Arturo Jiménez-Sánchez
- Instituto de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, Circuito Exterior s/n, De. Coyoacán 04510, Ciudad de México, Mexico.
| |
Collapse
|
16
|
Klier PEZ, Martin JG, Miller EW. Imaging Reversible Mitochondrial Membrane Potential Dynamics with a Masked Rhodamine Voltage Reporter. J Am Chem Soc 2021; 143:4095-4099. [PMID: 33710896 DOI: 10.1021/jacs.0c13110] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Mitochondria are the site of aerobic respiration, producing ATP via oxidative phosphorylation as protons flow down their electrochemical gradient through ATP synthase. This negative membrane potential across the inner mitochondrial membrane (ΔΨm) represents a fundamental biophysical parameter central to cellular life. Traditional, electrode-based methods for recording membrane potential are impossible to implement on mitochondria within intact cells. Fluorescent ΔΨm indicators based on cationic, lipophilic dyes are a common alternative, but these indicators are complicated by concentration-dependent artifacts and the requirement to maintain dye in the extracellular solution to visualize reversible ΔΨm dynamics. Here, we report the first example of a fluorescent ΔΨm reporter that does not rely on ΔΨm-dependent accumulation. We redirected the localization of a photoinduced electron transfer (PeT)-based indicator, Rhodamine Voltage Reporter (RhoVR), to mitochondria by masking the carboxylate of RhoVR 1 as an acetoxymethyl (AM) ester. Once within mitochondria, esterases remove the AM ester, trapping RhoVR inside of the mitochondrial matrix, where it can incorporate within the inner membrane and reversibly report on changes in ΔΨm. We show that this Small molecule, Permeable, Internally Redistributing for Inner membrane Targeting Rhodamine Voltage Reporter, or SPIRIT RhoVR, localizes to mitochondria across a number of different cell lines and responds reversibly to changes in ΔΨm induced by exceptionally low concentrations of the uncoupler FCCP without the need for exogenous pools of dye (unlike traditional, accumulation-based rhodamine esters). SPIRIT RhoVR is compatible with multi-color imaging, enabling simultaneous, real-time observation of cytosolic Ca2+, plasma membrane potential, and reversible ΔΨm dynamics.
Collapse
|
17
|
Schmidt CA, McLaughlin KL, Boykov IN, Mojalagbe R, Ranganathan A, Buddo KA, Lin CT, Fisher-Wellman KH, Neufer PD. Aglycemic growth enhances carbohydrate metabolism and induces sensitivity to menadione in cultured tumor-derived cells. Cancer Metab 2021; 9:3. [PMID: 33468237 PMCID: PMC7816515 DOI: 10.1186/s40170-021-00241-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 01/06/2021] [Indexed: 12/19/2022] Open
Abstract
Background Hepatocellular carcinoma (HCC) is the most prevalent form of liver malignancy and carries poor prognoses due to late presentation of symptoms. Treatment of late-stage HCC relies heavily on chemotherapeutics, many of which target cellular energy metabolism. A key platform for testing candidate chemotherapeutic compounds is the intrahepatic orthotopic xenograft (IOX) model in rodents. Translational efficacy from the IOX model to clinical use is limited (in part) by variation in the metabolic phenotypes of the tumor-derived cells that can be induced by selective adaptation to subculture conditions. Methods In this study, a detailed multilevel systems approach combining microscopy, respirometry, potentiometry, and extracellular flux analysis (EFA) was utilized to examine metabolic adaptations that occur under aglycemic growth media conditions in HCC-derived (HEPG2) cells. We hypothesized that aglycemic growth would result in adaptive “aerobic poise” characterized by enhanced capacity for oxidative phosphorylation over a range of physiological energetic demand states. Results Aglycemic growth did not invoke adaptive changes in mitochondrial content, network complexity, or intrinsic functional capacity/efficiency. In intact cells, aglycemic growth markedly enhanced fermentative glycolytic substrate-level phosphorylation during glucose refeeding and enhanced responsiveness of both fermentation and oxidative phosphorylation to stimulated energy demand. Additionally, aglycemic growth induced sensitivity of HEPG2 cells to the provitamin menadione at a 25-fold lower dose compared to control cells. Conclusions These findings indicate that growth media conditions have substantial effects on the energy metabolism of subcultured tumor-derived cells, which may have significant implications for chemotherapeutic sensitivity during incorporation in IOX testing panels. Additionally, the metabolic phenotyping approach used in this study provides a practical workflow that can be incorporated with IOX screening practices to aid in deciphering the metabolic underpinnings of chemotherapeutic drug sensitivity. Supplementary Information The online version contains supplementary material available at 10.1186/s40170-021-00241-0.
Collapse
Affiliation(s)
- Cameron A Schmidt
- East Carolina Diabetes and Obesity Institute, Greenville, NC, USA.,Dept. of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC, USA
| | - Kelsey L McLaughlin
- East Carolina Diabetes and Obesity Institute, Greenville, NC, USA.,Dept. of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC, USA
| | - Ilya N Boykov
- East Carolina Diabetes and Obesity Institute, Greenville, NC, USA.,Dept. of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC, USA
| | - Rafiq Mojalagbe
- East Carolina Diabetes and Obesity Institute, Greenville, NC, USA
| | | | - Katherine A Buddo
- East Carolina Diabetes and Obesity Institute, Greenville, NC, USA.,Dept. of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC, USA
| | - Chien-Te Lin
- East Carolina Diabetes and Obesity Institute, Greenville, NC, USA.,Dept. of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC, USA
| | - Kelsey H Fisher-Wellman
- East Carolina Diabetes and Obesity Institute, Greenville, NC, USA. .,Dept. of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC, USA.
| | - P Darrell Neufer
- East Carolina Diabetes and Obesity Institute, Greenville, NC, USA. .,Dept. of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC, USA.
| |
Collapse
|
18
|
Picture perfect: Imaging mitochondrial membrane potential changes in retina slices with minimal stray fluorescence. Exp Eye Res 2020; 202:108318. [PMID: 33091432 DOI: 10.1016/j.exer.2020.108318] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 09/24/2020] [Accepted: 10/14/2020] [Indexed: 11/23/2022]
Abstract
Mitochondrial membrane potential (Ψm) is a critical parameter that can be used to determine cellular well-being. As it is a direct measure of the cell's ATP generating capability, in recent years, this key component in cell biology has been the subject of thousands of biochemical and biophysical investigations. Membrane-permeant fluorescent dyes, like tetramethylrhodamine ethyl ester (TMRE), have been predominantly employed to monitor ΔΨm in cells. These dyes are typically lipophilic cationic compounds that equilibrate across membranes in a Nernstian fashion, thus accumulating into the mitochondrial membrane matrix space in inverse proportion to Ψm. However, the bath loading method practiced for labelling tissue slices with these cationic dyes poses limitations in the form of non-specificity and low signal to noise ratio, which compromises the precision of the results. Therefore, we introduce an alternative way for TMRE loading to image the ΔΨm in tissue slices by utilizing a low resistance glass pipette attached to a pressure injector. This method shows highly precise fluorescent dye labelling of the mitochondria and offers maximum output intensity, in turn enhancing signal to noise ratio.
Collapse
|
19
|
Zhang L, Townsend DM, Morris M, Maldonado EN, Jiang YL, Broome AM, Bethard JR, Ball LE, Tew KD. Voltage-Dependent Anion Channels Influence Cytotoxicity of ME-344, a Therapeutic Isoflavone. J Pharmacol Exp Ther 2020; 374:308-318. [PMID: 32546528 PMCID: PMC7372917 DOI: 10.1124/jpet.120.000009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 05/19/2020] [Indexed: 01/27/2023] Open
Abstract
ME-344 is a second-generation cytotoxic isoflavone with anticancer activity promulgated through interference with mitochondrial functions. Using a click chemistry version of the drug together with affinity-enriched mass spectrometry, voltage-dependent anion channels (VDACs) 1 and 2 were identified as drug targets. To determine the importance of VDAC1 or 2 to cytotoxicity, we used lung cancer cells that were either sensitive (H460) or intrinsically resistant (H596) to the drug. In H460 cells, depletion of VDAC1 and VDAC2 by small interfering RNA impacted ME-344 effects by diminishing generation of reactive oxygen species (ROS), preventing mitochondrial membrane potential dissipation, and moderating ME-344-induced cytotoxicity and mitochondrial-mediated apoptosis. Mechanistically, VDAC1 and VDAC2 knockdown prevented ME-344-induced apoptosis by inhibiting Bax mitochondrial translocation and cytochrome c release as well as apoptosis in these H460 cells. We conclude that VDAC1 and 2, as mediators of the response to oxidative stress, have roles in modulating ROS generation, Bax translocation, and cytochrome c release during mitochondrial-mediated apoptosis caused by ME-344. SIGNIFICANCE STATEMENT: Dissecting preclinical drug mechanisms are of significance in development of a drug toward eventual Food and Drug Administration approval.
Collapse
Affiliation(s)
- Leilei Zhang
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics (L.Z., M.M., E.N.M., Y.-L.J., A.-M.B., J.R.B., L.E.B., K.D.T.) and Department of Pharmaceutical and Biomedical Sciences (D.M.T.), Medical University of South Carolina, Charleston, South Carolina
| | - Danyelle M Townsend
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics (L.Z., M.M., E.N.M., Y.-L.J., A.-M.B., J.R.B., L.E.B., K.D.T.) and Department of Pharmaceutical and Biomedical Sciences (D.M.T.), Medical University of South Carolina, Charleston, South Carolina
| | - Morgan Morris
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics (L.Z., M.M., E.N.M., Y.-L.J., A.-M.B., J.R.B., L.E.B., K.D.T.) and Department of Pharmaceutical and Biomedical Sciences (D.M.T.), Medical University of South Carolina, Charleston, South Carolina
| | - Eduardo N Maldonado
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics (L.Z., M.M., E.N.M., Y.-L.J., A.-M.B., J.R.B., L.E.B., K.D.T.) and Department of Pharmaceutical and Biomedical Sciences (D.M.T.), Medical University of South Carolina, Charleston, South Carolina
| | - Yu-Lin Jiang
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics (L.Z., M.M., E.N.M., Y.-L.J., A.-M.B., J.R.B., L.E.B., K.D.T.) and Department of Pharmaceutical and Biomedical Sciences (D.M.T.), Medical University of South Carolina, Charleston, South Carolina
| | - Ann-Marie Broome
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics (L.Z., M.M., E.N.M., Y.-L.J., A.-M.B., J.R.B., L.E.B., K.D.T.) and Department of Pharmaceutical and Biomedical Sciences (D.M.T.), Medical University of South Carolina, Charleston, South Carolina
| | - Jennifer R Bethard
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics (L.Z., M.M., E.N.M., Y.-L.J., A.-M.B., J.R.B., L.E.B., K.D.T.) and Department of Pharmaceutical and Biomedical Sciences (D.M.T.), Medical University of South Carolina, Charleston, South Carolina
| | - Lauren E Ball
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics (L.Z., M.M., E.N.M., Y.-L.J., A.-M.B., J.R.B., L.E.B., K.D.T.) and Department of Pharmaceutical and Biomedical Sciences (D.M.T.), Medical University of South Carolina, Charleston, South Carolina
| | - Kenneth D Tew
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics (L.Z., M.M., E.N.M., Y.-L.J., A.-M.B., J.R.B., L.E.B., K.D.T.) and Department of Pharmaceutical and Biomedical Sciences (D.M.T.), Medical University of South Carolina, Charleston, South Carolina
| |
Collapse
|
20
|
Al-Zubaidi U, Liu J, Cinar O, Robker RL, Adhikari D, Carroll J. The spatio-temporal dynamics of mitochondrial membrane potential during oocyte maturation. Mol Hum Reprod 2020; 25:695-705. [PMID: 31579926 PMCID: PMC6884418 DOI: 10.1093/molehr/gaz055] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 09/03/2019] [Accepted: 09/13/2019] [Indexed: 12/31/2022] Open
Abstract
Mitochondria are highly dynamic organelles and their distribution, structure and activity affect a wide range of cellular functions. Mitochondrial membrane potential (∆Ψm) is an indicator of mitochondrial activity and plays a major role in ATP production, redox balance, signaling and metabolism. Despite the absolute reliance of oocyte and early embryo development on mitochondrial function, there is little known about the spatial and temporal aspects of ΔΨm during oocyte maturation. The one exception is that previous findings using a ΔΨm indicator, JC-1, report that mitochondria in the cortex show a preferentially increased ΔΨm, relative to the rest of the cytoplasm. Using live-cell imaging and a new ratiometric approach for measuring ΔΨm in mouse oocytes, we find that ΔΨm increases through the time course of oocyte maturation and that mitochondria in the vicinity of the first meiotic spindle show an increase in ΔΨm, compared to other regions of the cytoplasm. We find no evidence for an elevated ΔΨm in the oocyte cortex. These findings suggest that mitochondrial activity is adaptive and responsive to the events of oocyte maturation at both a global and local level. In conclusion, we have provided a new approach to reliably measure ΔΨm that has shed new light onto the spatio-temporal regulation of mitochondrial function in oocytes and early embryos.
Collapse
Affiliation(s)
- Usama Al-Zubaidi
- Development and Stem Cell Program and Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia.,Applied Embryology Department, High Institute for Infertility Diagnosis and Assisted Reproductive Technologies, AL-Nahrain University, Baghdad, Iraq
| | - Jun Liu
- Development and Stem Cell Program and Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
| | - Ozgur Cinar
- Development and Stem Cell Program and Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia.,Department of Histology and Embryology, Ankara University School of Medicine, Ankara, Turkey
| | - Rebecca L Robker
- Development and Stem Cell Program and Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia.,School of Pediatrics and Reproductive Health, Robinson Research Institute, The University of Adelaide, Adelaide, SA, 5005, Australia
| | - Deepak Adhikari
- Development and Stem Cell Program and Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
| | - John Carroll
- Development and Stem Cell Program and Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
| |
Collapse
|
21
|
Jin K, Ma Y, Manrique-Caballero CL, Li H, Emlet DR, Li S, Baty CJ, Wen X, Kim-Campbell N, Frank A, Menchikova EV, Pastor-Soler NM, Hallows KR, Jackson EK, Shiva S, Pinsky MR, Zuckerbraun BS, Kellum JA, Gómez H. Activation of AMP-activated protein kinase during sepsis/inflammation improves survival by preserving cellular metabolic fitness. FASEB J 2020; 34:7036-7057. [PMID: 32246808 DOI: 10.1096/fj.201901900r] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 01/24/2020] [Accepted: 03/18/2020] [Indexed: 01/08/2023]
Abstract
The purpose was to determine the role of AMPK activation in the renal metabolic response to sepsis, the development of sepsis-induced acute kidney injury (AKI) and on survival. In a prospective experimental study, 167 10- to 12-week-old C57BL/6 mice underwent cecal ligation and puncture (CLP) and human proximal tubule epithelial cells (TEC; HK2) were exposed to inflammatory mix (IM), a combination of lipopolysaccharide (LPS) and high mobility group box 1 (HMGB1). Renal/TEC metabolic fitness was assessed by monitoring the expression of drivers of oxidative phosphorylation (OXPHOS), the rates of utilization of OXPHOS/glycolysis in response to metabolic stress, and mitochondrial function by measuring O2 consumption rates (OCR) and the membrane potential (Δψm ). Sepsis/IM resulted in AKI, increased mortality, and in renal AMPK activation 6-24 hours after CLP/IM. Pharmacologic activation of AMPK with 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) or metformin during sepsis improved the survival, while AMPK inhibition with Compound C increased mortality, impaired mitochondrial respiration, decreased OCR, and disrupted TEC metabolic fitness. AMPK-driven protection was associated with increased Sirt 3 expression and restoration of metabolic fitness. Renal AMPK activation in response to sepsis/IM is an adaptive mechanism that protects TEC, organs, and the host by preserving mitochondrial function and metabolic fitness likely through Sirt3 signaling.
Collapse
Affiliation(s)
- Kui Jin
- Department of Critical Care, Anhui Provincial Hospital, He Fei, China
| | - Yujie Ma
- Department of Critical Care Medicine, Air Force Medical Center, Beijing, China
| | - Carlos L Manrique-Caballero
- Center for Critical Care Nephrology, Department of Critical Care Medicine, The CRISMA Center, University of Pittsburgh, Pittsburgh, PA, USA
| | - Hui Li
- Division of Nephrology and Hypertension and USC/UKRO Kidney Research Center, Department of Medicine, University of Southern California Keck School of Medicine, Los Angeles, CA, USA
| | - David R Emlet
- Center for Critical Care Nephrology, Department of Critical Care Medicine, The CRISMA Center, University of Pittsburgh, Pittsburgh, PA, USA
| | - Shengnan Li
- Department of Anesthesiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Catherine J Baty
- Renal Electrolyte Division, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Xiaoyan Wen
- Center for Critical Care Nephrology, Department of Critical Care Medicine, The CRISMA Center, University of Pittsburgh, Pittsburgh, PA, USA
| | - Nahmah Kim-Campbell
- Center for Critical Care Nephrology, Department of Critical Care Medicine, The CRISMA Center, University of Pittsburgh, Pittsburgh, PA, USA
| | - Alicia Frank
- Center for Critical Care Nephrology, Department of Critical Care Medicine, The CRISMA Center, University of Pittsburgh, Pittsburgh, PA, USA
| | - Elizabeth V Menchikova
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Nuria M Pastor-Soler
- Center for Critical Care Nephrology, Department of Critical Care Medicine, The CRISMA Center, University of Pittsburgh, Pittsburgh, PA, USA.,Division of Nephrology and Hypertension and USC/UKRO Kidney Research Center, Department of Medicine, University of Southern California Keck School of Medicine, Los Angeles, CA, USA
| | - Kenneth R Hallows
- Center for Critical Care Nephrology, Department of Critical Care Medicine, The CRISMA Center, University of Pittsburgh, Pittsburgh, PA, USA.,Division of Nephrology and Hypertension and USC/UKRO Kidney Research Center, Department of Medicine, University of Southern California Keck School of Medicine, Los Angeles, CA, USA
| | - Edwin K Jackson
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Sruti Shiva
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA.,Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Michael R Pinsky
- Center for Critical Care Nephrology, Department of Critical Care Medicine, The CRISMA Center, University of Pittsburgh, Pittsburgh, PA, USA
| | - Brian S Zuckerbraun
- Center for Critical Care Nephrology, Department of Critical Care Medicine, The CRISMA Center, University of Pittsburgh, Pittsburgh, PA, USA.,Department of Surgery, University of Pittsburgh, Pittsburgh, PA, USA
| | - John A Kellum
- Center for Critical Care Nephrology, Department of Critical Care Medicine, The CRISMA Center, University of Pittsburgh, Pittsburgh, PA, USA
| | - Hernando Gómez
- Center for Critical Care Nephrology, Department of Critical Care Medicine, The CRISMA Center, University of Pittsburgh, Pittsburgh, PA, USA.,Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, USA
| |
Collapse
|
22
|
Heslop KA, Rovini A, Hunt EG, Fang D, Morris ME, Christie CF, Gooz MB, DeHart DN, Dang Y, Lemasters JJ, Maldonado EN. JNK activation and translocation to mitochondria mediates mitochondrial dysfunction and cell death induced by VDAC opening and sorafenib in hepatocarcinoma cells. Biochem Pharmacol 2020; 171:113728. [PMID: 31759978 PMCID: PMC7309270 DOI: 10.1016/j.bcp.2019.113728] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 11/20/2019] [Indexed: 02/07/2023]
Abstract
The multikinase inhibitor sorafenib, and opening of voltage dependent anion channels (VDAC) by the erastin-like compound X1 promotes oxidative stress and mitochondrial dysfunction in hepatocarcinoma cells. Here, we hypothesized that X1 and sorafenib induce mitochondrial dysfunction by increasing reactive oxygen species (ROS) formation and activating c-Jun N-terminal kinases (JNKs), leading to translocation of activated JNK to mitochondria. Both X1 and sorafenib increased production of ROS and activated JNK. X1 and sorafenib caused a drop in mitochondrial membrane potential (ΔΨ), a readout of mitochondrial metabolism, after 60 min. Mitochondrial depolarization after X1 and sorafenib occurred in parallel with JNK activation, increased superoxide (O2•-) production, decreased basal and oligomycin sensitive respiration, and decreased maximal respiratory capacity. Increased production of O2•- after X1 or sorafenib was abrogated by JNK inhibition and antioxidants. S3QEL 2, a specific inhibitor of site IIIQo, at Complex III, prevented depolarization induced by X1. JNK inhibition by JNK inhibitors VIII and SP600125 also prevented mitochondrial depolarization. After X1, activated JNK translocated to mitochondria as assessed by proximity ligation assays. Tat-Sab KIM1, a peptide selectively preventing the binding of JNK to the outer mitochondrial membrane protein Sab, blocked the depolarization induced by X1 and sorafenib. X1 promoted cell death mostly by necroptosis that was partially prevented by JNK inhibition. These results indicate that JNK activation and translocation to mitochondria is a common mechanism of mitochondrial dysfunction induced by both VDAC opening and sorafenib.
Collapse
Affiliation(s)
- K A Heslop
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, United States
| | - A Rovini
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, United States
| | - E G Hunt
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, United States
| | - D Fang
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, United States
| | - M E Morris
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, United States
| | - C F Christie
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, United States
| | - M B Gooz
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, United States
| | - D N DeHart
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, United States
| | - Y Dang
- Department of Medicine, Medical University of South Carolina, Charleston, SC, United States
| | - J J Lemasters
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, United States; Department of Biochemistry & Molecular Biology, Medical University of South Carolina, Charleston, SC, United States; Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, United States
| | - E N Maldonado
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, United States; Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, United States.
| |
Collapse
|
23
|
Abstract
The integration of drugs into nanocarriers favorably altered their pharmacodynamics and pharmacokinetics compared to free drugs, and increased their therapeutic index. However, selective cellular internalization in diseased tissues rather than normal tissues still presents a formidable challenge. In this chapter I will cover solutions involving environment-responsive cell-penetrating peptides (CPPs). I will discuss properties of CPPs as universal cellular uptake enhancers, and the modifications imparted to CPP-modified nanocarriers to confine CPP activation to diseased tissues.
Collapse
|
24
|
The Role of Mitochondria in the Mechanisms of Cardiac Ischemia-Reperfusion Injury. Antioxidants (Basel) 2019; 8:antiox8100454. [PMID: 31590423 PMCID: PMC6826663 DOI: 10.3390/antiox8100454] [Citation(s) in RCA: 102] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 09/30/2019] [Accepted: 10/01/2019] [Indexed: 01/11/2023] Open
Abstract
Mitochondria play a critical role in maintaining cellular function by ATP production. They are also a source of reactive oxygen species (ROS) and proapoptotic factors. The role of mitochondria has been established in many aspects of cell physiology/pathophysiology, including cell signaling. Mitochondria may deteriorate under various pathological conditions, including ischemia-reperfusion (IR) injury. Mitochondrial injury can be one of the main causes for cardiac and other tissue injuries by energy stress and overproduction of toxic reactive oxygen species, leading to oxidative stress, elevated calcium and apoptotic and necrotic cell death. However, the interplay among these processes in normal and pathological conditions is still poorly understood. Mitochondria play a critical role in cardiac IR injury, where they are directly involved in several pathophysiological mechanisms. We also discuss the role of mitochondria in the context of mitochondrial dynamics, specializations and heterogeneity. Also, we wanted to stress the existence of morphologically and functionally different mitochondrial subpopulations in the heart that may have different sensitivities to diseases and IR injury. Therefore, various cardioprotective interventions that modulate mitochondrial stability, dynamics and turnover, including various pharmacologic agents, specific mitochondrial antioxidants and uncouplers, and ischemic preconditioning can be considered as the main strategies to protect mitochondrial and cardiovascular function and thus enhance longevity.
Collapse
|
25
|
Zhang X, Han X, Zhang P, Zhou T, Chen Y, Jin J, Ma X. Morin attenuates oxidized low-density lipoprotein-mediated injury by inducing autophagy via activating AMPK signalling in HUVECs. Clin Exp Pharmacol Physiol 2019; 46:1053-1060. [PMID: 31407376 DOI: 10.1111/1440-1681.13160] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 07/25/2019] [Accepted: 08/06/2019] [Indexed: 01/07/2023]
Abstract
Endothelial dysfunction is a precursor of cardiovascular disease, and oxidized low-density lipoprotein (ox-LDL) has been implicated in the development of atherosclerosis by directly targeting endothelial cells. Morin, a natural flavonol, has been shown to protect endothelial cells from dysfunction. The present study was designed to evaluate the effect of morin on ox-LDL-induced injury and to investigate the underlying molecular mechanisms in human umbilical vein endothelial cells (HUVECs). The results showed that morin alleviated ox-LDL-induced endothelial injury and promoted the viability of HUVECs exposed to ox-LDL. Morin significantly inhibited the oxidative stress induced by ox-LDL by inhibiting the production of reactive oxygen species and malondialdehyde, and downregulating the level of superoxide dismutase. Moreover, morin markedly attenuated the overexpressed mRNA levels of the inflammatory factors interleukin (IL)-1β, IL-6, and the adhesion molecules ICAM-1 and VCAM-1 induced by exposure to ox-LDL. We found that morin attenuated ox-LDL-induced injury in HUVECs by inducing autophagy. The protective effects of morin against ox-LDL-induced injury were dramatically reversed by chloroquine phosphate (CQ) treatment. Furthermore, morin up-regulated the expression of p-AMPK and down-regulated the level of p-mTOR in HUVECs exposed to ox-LDL, and this was significantly reversed by the AMPK inhibitor Compound C (CC). Taken together, our results demonstrated that morin attenuates ox-LDL-mediated injury by inducing autophagy via activating AMPK signalling in HUVECs.
Collapse
Affiliation(s)
- Xiaodong Zhang
- School of Pharmaceutical Sciences, Jiangnan University, Wuxi, China
| | - Xiping Han
- School of Pharmaceutical Sciences, Jiangnan University, Wuxi, China
| | - Peng Zhang
- Wuxi School of Medicine, Jiangnan University, Wuxi, China
| | - Tingting Zhou
- Wuxi School of Medicine, Jiangnan University, Wuxi, China
| | - Yun Chen
- School of Pharmaceutical Sciences, Jiangnan University, Wuxi, China
| | - Jian Jin
- School of Pharmaceutical Sciences, Jiangnan University, Wuxi, China
| | - Xin Ma
- Wuxi School of Medicine, Jiangnan University, Wuxi, China
| |
Collapse
|
26
|
Christie CF, Fang D, Hunt EG, Morris ME, Rovini A, Heslop KA, Beeson GC, Beeson CC, Maldonado EN. Statin-dependent modulation of mitochondrial metabolism in cancer cells is independent of cholesterol content. FASEB J 2019; 33:8186-8201. [PMID: 30951369 PMCID: PMC6593894 DOI: 10.1096/fj.201802723r] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 03/18/2019] [Indexed: 02/03/2023]
Abstract
Statins, widely used to treat hypercholesterolemia, inhibit the 3-hydroxy-3-methylglutaryl-coenzyme A reductase, the rate-limiting enzyme of de novo cholesterol (Chol) synthesis. Statins have been also reported to slow tumor progression. In cancer cells, ATP is generated both by glycolysis and oxidative phosphorylation. Mitochondrial membrane potential (ΔΨ), a readout of mitochondrial metabolism, is sustained by the oxidation of respiratory substrates in the Krebs cycle to generate NADH and flavin adenine dinucleotide, which are further oxidized by the respiratory chain. Here, we studied the short-term effects of statins (3-24 h) on mitochondrial metabolism on cancer cells. Lovastatin (LOV) and simvastatin (SIM) increased ΔΨ in HepG2 and Huh7 human hepatocarcinoma cells and HCC4006 human lung adenocarcinoma cells. Mitochondrial hyperpolarization after LOV and SIM was dose and time dependent. Maximal increase in ΔΨ occurred at 10 µM and 24 h for both statins. The structurally unrelated atorvastatin also hyperpolarized mitochondria in HepG2 cells. Cellular and mitochondrial Chol remained unchanged after SIM. Both LOV and SIM decreased basal respiration, ATP-linked respiration, and ATP production. LOV and SIM did not change the rate of lactic acid production. In summary, statins modulate mitochondrial metabolism in cancer cells independently of the Chol content in cellular membranes without affecting glycolysis.-Christie, C. F., Fang, D., Hunt, E. G., Morris, M. E., Rovini, A., Heslop, K. A., Beeson, G. C., Beeson, C. C., Maldonado, E. N. Statin-dependent modulation of mitochondrial metabolism in cancer cells is independent of cholesterol content.
Collapse
Affiliation(s)
- Charleston F. Christie
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Diana Fang
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Elizabeth G. Hunt
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Morgan E. Morris
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Amandine Rovini
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Kareem A. Heslop
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Gyda C. Beeson
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Craig C. Beeson
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Eduardo N. Maldonado
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, South Carolina, USA
- Hollings Cancer Center, Medical University of South Carolina, Charleston, South Carolina, USA
| |
Collapse
|
27
|
Abstract
Background:
Since the serendipitous discovery of the antitumor activity of cisplatin
there has been a continuous surge in studies aimed at the development of new cytotoxic
metal complexes. While the majority of these complexes have been designed to interact with
nuclear DNA, other targets for anticancer metallodrugs attract increasing interest. In cancer
cells the mitochondrial metabolism is deregulated. Impaired apoptosis, insensitivity to antigrowth
signals and unlimited proliferation have been linked to mitochondrial dysfunction. It
is therefore not surprising that mitochondria have emerged as a major target for cancer therapy.
Mitochondria-targeting agents are able to bypass resistance mechanisms and to (re-) activate
cell-death programs.
Methods:
Web-based literature searching tools such as SciFinder were used to search for reports
on cytotoxic metal complexes that are taken up by the mitochondria and interact with
mitochondrial DNA or mitochondrial proteins, disrupt the mitochondrial membrane potential,
facilitate mitochondrial membrane permeabilization or activate mitochondria-dependent celldeath
signaling by unbalancing the cellular redox state. Included in the search were publications
investigating strategies to selectively accumulate metallodrugs in the mitochondria.
Results:
This review includes 241 references on antimitochondrial metal complexes, the use
of mitochondria-targeting carrier ligands and the formation of lipophilic cationic complexes.
Conclusion:
Recent developments in the design, cytotoxic potency, and mechanistic understanding
of antimitochondrial metal complexes, in particular of cyclometalated Au, Ru, Ir and
Pt complexes, Ru polypyridine complexes and Au-N-heterocyclic carbene and phosphine
complexes are summarized and discussed.
Collapse
Affiliation(s)
- Andrea Erxleben
- School of Chemistry, National University of Ireland, Galway, Ireland
| |
Collapse
|
28
|
Zhang Y, Wang ZH, Liu Y, Chen Y, Sun N, Gucek M, Zhang F, Xu H. PINK1 Inhibits Local Protein Synthesis to Limit Transmission of Deleterious Mitochondrial DNA Mutations. Mol Cell 2019; 73:1127-1137.e5. [PMID: 30772175 DOI: 10.1016/j.molcel.2019.01.013] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 11/05/2018] [Accepted: 01/09/2019] [Indexed: 12/22/2022]
Abstract
We have previously proposed that selective inheritance, the limited transmission of damaging mtDNA mutations from mother to offspring, is based on replication competition in Drosophila melanogaster. This model, which stems from our observation that wild-type mitochondria propagate much more vigorously in the fly ovary than mitochondria carrying fitness-impairing mutations, implies that germ cells recognize the fitness of individual mitochondria and selectively boost the propagation of healthy ones. Here, we demonstrate that the protein kinase PINK1 preferentially accumulates on mitochondria enriched for a deleterious mtDNA mutation. PINK1 phosphorylates Larp to inhibit protein synthesis on the mitochondrial outer membrane. Impaired local translation on defective mitochondria in turn limits the replication of their mtDNA and hence the transmission of deleterious mutations to the offspring. Our work confirms that selective inheritance occurs at the organelle level during Drosophila oogenesis and provides molecular entry points to test this model in other systems.
Collapse
Affiliation(s)
- Yi Zhang
- National Heart, Lung, and Blood Institute, NIH, Bethesda, MD 20892, USA
| | - Zong-Heng Wang
- National Heart, Lung, and Blood Institute, NIH, Bethesda, MD 20892, USA
| | - Yi Liu
- National Heart, Lung, and Blood Institute, NIH, Bethesda, MD 20892, USA
| | - Yong Chen
- National Heart, Lung, and Blood Institute, NIH, Bethesda, MD 20892, USA
| | - Nuo Sun
- National Heart, Lung, and Blood Institute, NIH, Bethesda, MD 20892, USA
| | - Marjan Gucek
- National Heart, Lung, and Blood Institute, NIH, Bethesda, MD 20892, USA
| | - Fan Zhang
- National Heart, Lung, and Blood Institute, NIH, Bethesda, MD 20892, USA
| | - Hong Xu
- National Heart, Lung, and Blood Institute, NIH, Bethesda, MD 20892, USA.
| |
Collapse
|
29
|
Peña B, Saha S, Barhoumi R, Burghardt RC, Dunbar KR. Ruthenium(II)-Polypyridyl Compounds with π-Extended Nitrogen Donor Ligands Induce Apoptosis in Human Lung Adenocarcinoma (A549) Cells by Triggering Caspase-3/7 Pathway. Inorg Chem 2018; 57:12777-12786. [PMID: 30239197 DOI: 10.1021/acs.inorgchem.8b01988] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Ru(II)-polypyridyl complexes exhibit antitumor properties that can be systematically tailored by means of adjusting the ligand environment. In this work, the effect of incorporating π-extended moieties into anionic N∧O- based chelating ligands on the cytotoxic properties of Ru compounds is explored. Four new Ru(II) complexes, [Ru(bpy)2(dphol)][PF6] (1; bpy = 2,2'-bipyridine, dphol = dibenzo[ a, c]phenazin-10-olate), [Ru(phen)2(dphol)][PF6] (2; phen = 1,10-phenanthroline), [Ru(bpy)2(hbtz)][PF6] (3; hbtz = 2-(benzo[ d]thiazol-2-yl)phenolate), and [Ru(phen)2(hbtz)][PF6] (4) were synthesized and thoroughly characterized. In vitro cytotoxicity was investigated in human lung adenocarcinoma (A549) cells, which revealed that 4 is the most cytotoxic compound (IC50 = 0.8 μM) in the series including a control compound [Ru(bpy)2(quo)][PF6] (5; quo = 8-hydroxyquinolinate) and is nearly 8-fold more cytotoxic than cisplatin. An investigation of the mechanism of cell death led to the finding that compounds 1-4 disrupt the mitochondrial transmembrane potential (ΔΨm) in a concentration-dependent fashion, which is an event associated with the intrinsic pathway of apoptosis. Moreover, compound 4 triggers the activity of caspase-3/7, which eventually induces the apoptotic cellular death of A549 cells. Thus, increasing the overall lipophilicity of the Ru compounds by introducing π-extended moieties in the anionic N∧O- ligand is a successful strategy for realizing a new family of pro-apoptotic compounds with a [RuIIN5O]+ coordination environment.
Collapse
Affiliation(s)
- Bruno Peña
- Department of Chemistry , Texas A&M University , College Station , Texas 77843 , United States
| | - Sayan Saha
- Department of Chemistry , Texas A&M University , College Station , Texas 77843 , United States
| | - Rola Barhoumi
- Department of Veterinary Integrative Biosciences , Texas A&M University , College Station , Texas 77843 , United States
| | - Robert C Burghardt
- Department of Veterinary Integrative Biosciences , Texas A&M University , College Station , Texas 77843 , United States
| | - Kim R Dunbar
- Department of Chemistry , Texas A&M University , College Station , Texas 77843 , United States
| |
Collapse
|
30
|
Zorova LD, Popkov VA, Plotnikov EY, Silachev DN, Pevzner IB, Jankauskas SS, Babenko VA, Zorov SD, Balakireva AV, Juhaszova M, Sollott SJ, Zorov DB. Mitochondrial membrane potential. Anal Biochem 2018; 552:50-59. [PMID: 28711444 PMCID: PMC5792320 DOI: 10.1016/j.ab.2017.07.009] [Citation(s) in RCA: 1134] [Impact Index Per Article: 189.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 07/06/2017] [Accepted: 07/07/2017] [Indexed: 01/13/2023]
Abstract
The mitochondrial membrane potential (ΔΨm) generated by proton pumps (Complexes I, III and IV) is an essential component in the process of energy storage during oxidative phosphorylation. Together with the proton gradient (ΔpH), ΔΨm forms the transmembrane potential of hydrogen ions which is harnessed to make ATP. The levels of ΔΨm and ATP in the cell are kept relatively stable although there are limited fluctuations of both these factors that can occur reflecting normal physiological activity. However, sustained changes in both factors may be deleterious. A long-lasting drop or rise of ΔΨm vs normal levels may induce unwanted loss of cell viability and be a cause of various pathologies. Among other factors, ΔΨm plays a key role in mitochondrial homeostasis through selective elimination of dysfunctional mitochondria. It is also a driving force for transport of ions (other than H+) and proteins which are necessary for healthy mitochondrial functioning. We propose additional potential mechanisms for which ΔΨm is essential for maintenance of cellular health and viability and provide recommendations how to accurately measure ΔΨm in a cell and discuss potential sources of artifacts.
Collapse
Affiliation(s)
- Ljubava D Zorova
- A.N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russian Federation; International Laser Center, Lomonosov Moscow State University, Moscow, Russian Federation
| | - Vasily A Popkov
- A.N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russian Federation; Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, Russian Federation
| | - Egor Y Plotnikov
- A.N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russian Federation
| | - Denis N Silachev
- A.N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russian Federation
| | - Irina B Pevzner
- A.N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russian Federation
| | - Stanislovas S Jankauskas
- A.N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russian Federation
| | - Valentina A Babenko
- A.N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russian Federation; Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, Russian Federation
| | - Savva D Zorov
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, Russian Federation
| | - Anastasia V Balakireva
- Institute of Molecular Medicine, Sechenov First Moscow State Medical University, Moscow, Russian Federation
| | - Magdalena Juhaszova
- Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Steven J Sollott
- Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Dmitry B Zorov
- A.N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russian Federation; Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA.
| |
Collapse
|
31
|
Jiménez-Sánchez A, Lei EK, Kelley SO. A Multifunctional Chemical Probe for the Measurement of Local Micropolarity and Microviscosity in Mitochondria. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201802796] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Arturo Jiménez-Sánchez
- Department of Biochemistry; Faculty of Medicine; University of Toronto; Toronto Ontario M5S 1A8 Canada
| | - Eric K. Lei
- Department of Biochemistry; Faculty of Medicine; University of Toronto; Toronto Ontario M5S 1A8 Canada
| | - Shana O. Kelley
- Department of Biochemistry; Faculty of Medicine; University of Toronto; Toronto Ontario M5S 1A8 Canada
- Department of Pharmaceutical Sciences; Leslie Dan Faculty of Pharmacy; Institute for Biomedical and Biomaterials Engineering; Departments of Biochemistry and Chemistry; University of Toronto; Toronto Ontario M5S 1A8 Canada
| |
Collapse
|
32
|
Jiménez-Sánchez A, Lei EK, Kelley SO. A Multifunctional Chemical Probe for the Measurement of Local Micropolarity and Microviscosity in Mitochondria. Angew Chem Int Ed Engl 2018; 57:8891-8895. [PMID: 29808513 DOI: 10.1002/anie.201802796] [Citation(s) in RCA: 109] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 05/06/2018] [Indexed: 12/13/2022]
Abstract
The measurement of physicochemical parameters in living cells can provide information on individual cellular organelles, helping us to understand subcellular function in health and disease. While organelle-specific chemical probes have allowed qualitative evaluation of microenvironmental variations, the simultaneous quantification of mitochondrial local microviscosity (ηm ) and micropolarity (ϵm ), along with concurrent structural variations, has remained an unmet need. Herein, we describe a new multifunctional mitochondrial probe (MMP) for simultaneous monitoring of ηm and ϵm by fluorescence lifetime and emission intensity recordings, respectively. The MMP enables highly precise measurements of ηm and ϵm in the presence of a variety of agents perturbing cellular function, and the observed changes can also be correlated with alterations in mitochondrial network morphology and motility. This strategy represents a promising tool for the analysis of subtle changes in organellar structure.
Collapse
Affiliation(s)
- Arturo Jiménez-Sánchez
- Department of Biochemistry, Faculty of Medicine, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
| | - Eric K Lei
- Department of Biochemistry, Faculty of Medicine, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
| | - Shana O Kelley
- Department of Biochemistry, Faculty of Medicine, University of Toronto, Toronto, Ontario, M5S 1A8, Canada.,Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, Institute for Biomedical and Biomaterials Engineering, Departments of Biochemistry and Chemistry, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
| |
Collapse
|
33
|
Abstract
Laser scanning confocal microscopy provides the ability to image submicron sections in living cells and tissues. In conjunction with pH-indicating fluorescent probes, confocal microscopy can be used to visualize the distribution of pH inside living cells. Here we describe a confocal microscopic technique to image intracellular pH in living cells using carboxyseminaphthorhodafluor-1 (SNARF-1), a ratiometric pH-indicating fluorescent probe. SNARF-1 is ester-loaded into the cytosol and mitochondria of adult cardiac myocytes or other cell type. Using 568-nm excitation, emitted fluorescence longer and shorter than 595-nm is imaged and then ratioed after background subtraction. Ratio values for each pixel are converted to values of pH using a standard curve (lookup table). Images of the intracellular distribution of pH show cytosolic and nuclear areas to have a pH of ~7.1, but in regions corresponding to mitochondria, pH is 8.0, giving a mitochondrial ΔpH of 0.9. During hypoxia, mitochondrial pH decreases to cytosolic values, signifying the collapse of ΔpH. These results illustrate the ability of laser scanning confocal microscopy to image the intracellular distribution of pH in living cells and to determine mitochondrial ΔpH.
Collapse
Affiliation(s)
- Venkat K Ramshesh
- Center for Cell Death, Injury & Regeneration, Department of Drug Discovery & Biomedical Sciences, and Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, USA.,GE Healthcare Life Sciences, Marlborough, MA, USA
| | - John J Lemasters
- Center for Cell Death, Injury & Regeneration, Department of Drug Discovery & Biomedical Sciences, and Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, USA. .,Center for Cell Death, Injury & Regeneration, Department of Biochemistry & Molecular Biology, and Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, USA.
| |
Collapse
|
34
|
Harwig MC, Viana MP, Egner JM, Harwig JJ, Widlansky ME, Rafelski SM, Hill RB. Methods for imaging mammalian mitochondrial morphology: A prospective on MitoGraph. Anal Biochem 2018; 552:81-99. [PMID: 29505779 DOI: 10.1016/j.ab.2018.02.022] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 02/06/2018] [Accepted: 02/22/2018] [Indexed: 12/22/2022]
Abstract
Mitochondria are found in a variety of shapes, from small round punctate structures to a highly interconnected web. This morphological diversity is important for function, but complicates quantification. Consequently, early quantification efforts relied on various qualitative descriptors that understandably reduce the complexity of the network leading to challenges in consistency across the field. Recent application of state-of-the-art computational tools have resulted in more quantitative approaches. This prospective highlights the implementation of MitoGraph, an open-source image analysis platform for measuring mitochondrial morphology initially optimized for use with Saccharomyces cerevisiae. Here Mitograph was assessed on five different mammalian cells types, all of which were accurately segmented by MitoGraph analysis. MitoGraph also successfully differentiated between distinct mitochondrial morphologies that ranged from entirely fragmented to hyper-elongated. General recommendations are also provided for confocal imaging of labeled mitochondria (using mito-YFP, MitoTracker dyes and immunostaining parameters). Widespread adoption of MitoGraph will help achieve a long-sought goal of consistent and reproducible quantification of mitochondrial morphology.
Collapse
Affiliation(s)
- Megan C Harwig
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI, 53226, United States
| | - Matheus P Viana
- Visual Analytics and Comprehension Group, IBM Research, Brazil; Department of Developmental and Cell Biology and Center for Complex Biological Systems, University of California Irvine, Irvine, CA, 92697, United States
| | - John M Egner
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI, 53226, United States
| | | | - Michael E Widlansky
- Division of Cardiovascular Medicine, Department of Medicine, Medical College of Wisconsin, Milwaukee, WI, 53226, United States
| | - Susanne M Rafelski
- Department of Developmental and Cell Biology and Center for Complex Biological Systems, University of California Irvine, Irvine, CA, 92697, United States; Assay Development, Allen Institute for Cell Science, Seattle, WA, 98109, United States
| | - R Blake Hill
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI, 53226, United States.
| |
Collapse
|
35
|
Nicholls DG. Fluorescence Measurement of Mitochondrial Membrane Potential Changes in Cultured Cells. Methods Mol Biol 2018; 1782:121-135. [PMID: 29850997 DOI: 10.1007/978-1-4939-7831-1_7] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The mitochondrial membrane potential is the dominant component of the proton-motive force that is the potential term in the proton circuit linking electron transport to ATP synthesis and other energy-dependent mitochondrial processes. Cationic fluorescent probes have been used for many years to detect gross qualitative changes in mitochondrial membrane potentials in intact cell culture. In this chapter I describe how these fluorescence signals may be used to obtain a semiquantitative measure of changes in mitochondrial membrane potential.
Collapse
|
36
|
DeHart DN, Fang D, Heslop K, Li L, Lemasters JJ, Maldonado EN. Opening of voltage dependent anion channels promotes reactive oxygen species generation, mitochondrial dysfunction and cell death in cancer cells. Biochem Pharmacol 2017; 148:155-162. [PMID: 29289511 DOI: 10.1016/j.bcp.2017.12.022] [Citation(s) in RCA: 128] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 12/26/2017] [Indexed: 12/25/2022]
Abstract
Enhancement of aerobic glycolysis and suppression of mitochondrial metabolism characterize the pro-proliferative Warburg phenotype of cancer cells. High free tubulin in cancer cells closes voltage dependent anion channels (VDAC) to decrease mitochondrial membrane potential (ΔΨ), an effect antagonized by erastin, the canonical promotor of ferroptosis. Previously, we identified six compounds (X1-X6) that also block tubulin-dependent mitochondrial depolarization. Here, we hypothesized that VDAC opening after erastin and X1-X6 increases mitochondrial metabolism and reactive oxygen species (ROS) formation, leading to ROS-dependent mitochondrial dysfunction, bioenergetic failure and cell death. Accordingly, we characterized erastin and the two most potent structurally unrelated lead compounds, X1 and X4, on ROS formation, mitochondrial function and cell viability. Erastin, X1 and X4 increased ΔΨ followed closely by an increase in mitochondrial ROS generation within 30-60 min. Subsequently, mitochondria began to depolarize after an hour or longer indicative of mitochondrial dysfunction. N-acetylcysteine (NAC, glutathione precursor and ROS scavenger) and MitoQ (mitochondrially targeted antioxidant) blocked increased ROS formation after X1 and prevented mitochondrial dysfunction. Erastin, X1 and X4 selectively promoted cell killing in HepG2 and Huh7 human hepatocarcinoma cells compared to primary rat hepatocytes. X1 and X4-dependent cell death was blocked by NAC. These results suggest that ferroptosis induced by erastin and our erastin-like lead compounds was caused by VDAC opening, leading to increased ΔΨ, mitochondrial ROS generation and oxidative stress-induced cell death.
Collapse
Affiliation(s)
- David N DeHart
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, United States
| | - Diana Fang
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, United States
| | - Kareem Heslop
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, United States
| | - Li Li
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, United States
| | - John J Lemasters
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, United States; Department of Biochemistry & Molecular Biology, Medical University of South Carolina, Charleston, SC, United States; Center for Cell Death, Injury & Regeneration, Medical University of South Carolina, Charleston, SC, United States; Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, United States; Institute of Theoretical and Experimental Biophysics, Pushchino, Russia.
| | - Eduardo N Maldonado
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, United States; Center for Cell Death, Injury & Regeneration, Medical University of South Carolina, Charleston, SC, United States; Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, United States.
| |
Collapse
|
37
|
Chuang GC, Xia H, Mahne SE, Varner KJ. Environmentally Persistent Free Radicals Cause Apoptosis in HL-1 Cardiomyocytes. Cardiovasc Toxicol 2017; 17:140-149. [PMID: 27052339 DOI: 10.1007/s12012-016-9367-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Samples of environmental particulate matter contain environmentally persistent free radicals (EPFRs) capable of sustained generation of oxygen radicals. While exposure to EPFRs produces cardiac toxicity and oxidative stress in experimental animals, the underlying mechanisms are largely unknown. To determine whether EPFRs could directly damage cardiomyocytes, cultured mouse cardiomyocytes (HL-1) and primary rat adult left ventricular myocytes (ALVM) were incubated with an EPFR consisting of 1,2-dichlorobenzene chemisorbed to CuO-coated silica beads (DCB230). Treatment with DCB230 killed both HL-1 and ALVM in a dose- and time-dependent manner. The cytotoxic effects of DCB230 were significantly attenuated by treatment with α-tocopherol. One to 2 h after exposure to DCB230, there were significant reductions in mitochondrial membrane potential and significant increases in cleaved caspase-9, but no significant increases in DNA damage or cell death. After 8 h of treatment, there were significant increases in caspase-3, caspase-9, DNA damage and PARP cleavage associated with significant cell death. Together, these data indicate that DCB230 kills HL-1 myocytes by inducing oxidative stress that initiates apoptosis, with the intrinsic or mitochondrial pathway acting early in the apoptotic signaling process.
Collapse
Affiliation(s)
- Gin C Chuang
- Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Sciences Center New Orleans, 1901 Perdido St, MEB 5262, New Orleans, LA, USA.,Superfund Research Center, Louisiana State University, Baton Rouge, LA, USA
| | - Huijing Xia
- Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Sciences Center New Orleans, 1901 Perdido St, MEB 5262, New Orleans, LA, USA.,Cardiovascular Center of Excellence, Louisiana State University Health Sciences Center New Orleans, New Orleans, LA, USA.,Superfund Research Center, Louisiana State University, Baton Rouge, LA, USA
| | - Sarah E Mahne
- Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Sciences Center New Orleans, 1901 Perdido St, MEB 5262, New Orleans, LA, USA.,Cardiovascular Center of Excellence, Louisiana State University Health Sciences Center New Orleans, New Orleans, LA, USA
| | - Kurt J Varner
- Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Sciences Center New Orleans, 1901 Perdido St, MEB 5262, New Orleans, LA, USA. .,Cardiovascular Center of Excellence, Louisiana State University Health Sciences Center New Orleans, New Orleans, LA, USA. .,Superfund Research Center, Louisiana State University, Baton Rouge, LA, USA.
| |
Collapse
|
38
|
DeHart DN, Lemasters JJ, Maldonado EN. Erastin-Like Anti-Warburg Agents Prevent Mitochondrial Depolarization Induced by Free Tubulin and Decrease Lactate Formation in Cancer Cells. SLAS DISCOVERY 2017; 23:23-33. [PMID: 29024608 DOI: 10.1177/2472555217731556] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
In Warburg metabolism, suppression of mitochondrial metabolism contributes to a low cytosolic ATP/ADP ratio favoring enhanced aerobic glycolysis. Flux of metabolites across the mitochondrial outer membrane occurs through voltage-dependent anion channels (VDAC). In cancer cells, free dimeric tubulin induces VDAC closure and dynamically regulates mitochondrial membrane potential (ΔΨ). Erastin, a small molecule that binds to VDAC, antagonizes the inhibitory effect of tubulin on VDAC and hyperpolarizes mitochondria in intact cells. Here, our aim was to identify novel compounds from the ChemBridge DIVERSet library that block the inhibitory effect of tubulin on ΔΨ using cell-based screening. HCC4006 cells were treated with nocodazole (NCZ) to increase free tubulin and decrease ΔΨ in the presence or absence of library compounds. Tetramethylrhodamine methylester (TMRM) fluorescence was assessed by high-content imaging to determine changes in ΔΨ. Compounds were considered positive if ΔΨ increased in the presence of NCZ. Using confocal microscopy, we identified and validated six lead molecules that antagonized the depolarizing effect of NCZ. Lead compounds and erastin did not promote microtubule stabilization, so changes in ΔΨ were independent of tubulin dynamics. The most potent lead compound also decreased lactate formation. These novel small molecules represent a potential new class of anti-Warburg drugs.
Collapse
Affiliation(s)
- David N DeHart
- 1 Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, SC, USA.,3 Center for Cell Death, Injury and Regeneration, Medical University of South Carolina, Charleston, SC, USA
| | - John J Lemasters
- 1 Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, SC, USA.,4 Institute of Theoretical and Experimental Biophysics, Pushchino, Russia
| | - Eduardo N Maldonado
- 1 Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, SC, USA.,3 Center for Cell Death, Injury and Regeneration, Medical University of South Carolina, Charleston, SC, USA
| |
Collapse
|
39
|
Ramírez-García G, Gutiérrez-Granados S, Gallegos-Corona MA, Palma-Tirado L, d'Orlyé F, Varenne A, Mignet N, Richard C, Martínez-Alfaro M. Long-term toxicological effects of persistent luminescence nanoparticles after intravenous injection in mice. Int J Pharm 2017; 532:686-695. [PMID: 28705622 DOI: 10.1016/j.ijpharm.2017.07.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 07/05/2017] [Accepted: 07/06/2017] [Indexed: 11/15/2022]
Abstract
The ZnGa1.995Cr0.005O4 persistent luminescence nanoparticles offer the promise of revolutionary tools for biological imaging with applications such as cell tracking or tumor detection. They can be re-excited through living tissues by visible photons, allowing observations without any time constraints and avoiding the undesirable auto-fluorescence signals observed when fluorescent probes are used. Despite all these advantages, their uses demand extensive toxicological evaluation and control. With this purpose, mice were injected with a single intravenous administration of hydroxylated or PEGylated persistent luminescence nanoparticles at different concentrations and then a set of standard tests were carried out 1day, 1 month and 6 months after the administration. High concentrations of hydroxylated nanoparticles generate structural alterations at histology level, endoplasmic reticulum damage and oxidative stress in liver, as well as rising in white blood cells counts. A mechanism involving the endoplasmic reticulum damage could be the responsible of the observed injuries in case of ZGO-OH. On the contrary, no toxicological effects related to PEGylated nanoprobes treatment were noted during our in vivo experiments, denoting the protective effect of PEG-functionalization and thereby, their potential as biocompatible in vivo diagnostic probes.
Collapse
Affiliation(s)
- Gonzalo Ramírez-García
- Departamento de Farmacia, Universidad de Guanajuato, 36050, Guanajuato, Mexico; Departamento de Química, Universidad de Guanajuato, 36050, Guanajuato, Mexico; Chimie ParisTech, PSL Research University, Unité de Technologies Chimiques et Biologiques pour la Santé (UTCBS), F-75005, Paris, France; INSERM, UTCBS (U 1022), F-75006, Paris, France; CNRS, UTCBS UMR 8258, F-75006 Paris, France; Université Paris Descartes, Sorbonne Paris Cité, UTCBS U 1022, F-75006 Paris, France
| | | | | | | | - Fanny d'Orlyé
- Chimie ParisTech, PSL Research University, Unité de Technologies Chimiques et Biologiques pour la Santé (UTCBS), F-75005, Paris, France; INSERM, UTCBS (U 1022), F-75006, Paris, France; CNRS, UTCBS UMR 8258, F-75006 Paris, France; Université Paris Descartes, Sorbonne Paris Cité, UTCBS U 1022, F-75006 Paris, France
| | - Anne Varenne
- Chimie ParisTech, PSL Research University, Unité de Technologies Chimiques et Biologiques pour la Santé (UTCBS), F-75005, Paris, France; INSERM, UTCBS (U 1022), F-75006, Paris, France; CNRS, UTCBS UMR 8258, F-75006 Paris, France; Université Paris Descartes, Sorbonne Paris Cité, UTCBS U 1022, F-75006 Paris, France
| | - Nathalie Mignet
- Chimie ParisTech, PSL Research University, Unité de Technologies Chimiques et Biologiques pour la Santé (UTCBS), F-75005, Paris, France; INSERM, UTCBS (U 1022), F-75006, Paris, France; CNRS, UTCBS UMR 8258, F-75006 Paris, France; Université Paris Descartes, Sorbonne Paris Cité, UTCBS U 1022, F-75006 Paris, France
| | - Cyrille Richard
- Chimie ParisTech, PSL Research University, Unité de Technologies Chimiques et Biologiques pour la Santé (UTCBS), F-75005, Paris, France; INSERM, UTCBS (U 1022), F-75006, Paris, France; CNRS, UTCBS UMR 8258, F-75006 Paris, France; Université Paris Descartes, Sorbonne Paris Cité, UTCBS U 1022, F-75006 Paris, France.
| | | |
Collapse
|
40
|
Abstract
The pancreatic β-cell secretes insulin in response to elevated plasma glucose. This review applies an external bioenergetic critique to the central processes of glucose-stimulated insulin secretion, including glycolytic and mitochondrial metabolism, the cytosolic adenine nucleotide pool, and its interaction with plasma membrane ion channels. The control mechanisms responsible for the unique responsiveness of the cell to glucose availability are discussed from bioenergetic and metabolic control standpoints. The concept of coupling factor facilitation of secretion is critiqued, and an attempt is made to unravel the bioenergetic basis of the oscillatory mechanisms controlling secretion. The need to consider the physiological constraints operating in the intact cell is emphasized throughout. The aim is to provide a coherent pathway through an extensive, complex, and sometimes bewildering literature, particularly for those unfamiliar with the field.
Collapse
Affiliation(s)
- David G Nicholls
- Buck Institute for Research on Aging, Novato, California; and Department of Clinical Sciences, Unit of Molecular Metabolism, Lund University Diabetes Centre, Malmo, Sweden
| |
Collapse
|
41
|
Jones E, Gaytan N, Garcia I, Herrera A, Ramos M, Agarwala D, Rana M, Innis-Whitehouse W, Schuenzel E, Gilkerson R. A threshold of transmembrane potential is required for mitochondrial dynamic balance mediated by DRP1 and OMA1. Cell Mol Life Sci 2017; 74:1347-1363. [PMID: 27858084 PMCID: PMC5346411 DOI: 10.1007/s00018-016-2421-9] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 11/06/2016] [Accepted: 11/14/2016] [Indexed: 12/22/2022]
Abstract
As an organellar network, mitochondria dynamically regulate their organization via opposing fusion and fission pathways to maintain bioenergetic homeostasis and contribute to key cellular pathways. This dynamic balance is directly linked to bioenergetic function: loss of transmembrane potential across the inner membrane (Δψ m) disrupts mitochondrial fission/fusion balance, causing fragmentation of the network. However, the level of Δψ m required for mitochondrial dynamic balance, as well as the relative contributions of fission and fusion pathways, have remained unclear. To explore this, mitochondrial morphology and Δψ m were examined via confocal imaging and tetramethyl rhodamine ester (TMRE) flow cytometry, respectively, in cultured 143B osteosarcoma cells. When normalized to the TMRE value of untreated 143B cells as 100%, both genetic (mtDNA-depleted ρ0) and pharmacological [carbonyl cyanide m-chlorophenyl hydrazone (CCCP)-treated] cell models below 34% TMRE fluorescence were unable to maintain mitochondrial interconnection, correlating with loss of fusion-active long OPA1 isoforms (L-OPA1). Mechanistically, this threshold is maintained by mechanistic coordination of DRP1-mediated fission and OPA1-mediated fusion: cells lacking either DRP1 or the OMA1 metalloprotease were insensitive to loss of Δψ m, instead maintaining an obligately fused morphology. Collectively, these findings demonstrate a mitochondrial 'tipping point' threshold mediated by the interaction of Δψ m with both DRP1 and OMA1; moreover, DRP1 appears to be required for effective OPA1 maintenance and processing, consistent with growing evidence for direct interaction of fission and fusion pathways. These results suggest that Δψ m below threshold coordinately activates both DRP1-mediated fission and OMA1 cleavage of OPA1, collapsing mitochondrial dynamic balance, with major implications for a range of signaling pathways and cellular life/death events.
Collapse
Affiliation(s)
- Edith Jones
- Department of Biology, The University of Texas Rio Grande Valley, 1201 West University Drive, Edinburg, TX, 78539-2999, USA
| | - Norma Gaytan
- Department of Biology, The University of Texas Rio Grande Valley, 1201 West University Drive, Edinburg, TX, 78539-2999, USA
| | - Iraselia Garcia
- Department of Biology, The University of Texas Rio Grande Valley, 1201 West University Drive, Edinburg, TX, 78539-2999, USA
| | - Alan Herrera
- Department of Biology, The University of Texas Rio Grande Valley, 1201 West University Drive, Edinburg, TX, 78539-2999, USA
| | - Manuel Ramos
- Department of Biology, The University of Texas Rio Grande Valley, 1201 West University Drive, Edinburg, TX, 78539-2999, USA
| | - Divya Agarwala
- Department of Biology, The University of Texas Rio Grande Valley, 1201 West University Drive, Edinburg, TX, 78539-2999, USA
| | - Maahrose Rana
- Department of Biology, The University of Texas Rio Grande Valley, 1201 West University Drive, Edinburg, TX, 78539-2999, USA
| | - Wendy Innis-Whitehouse
- Department of Biomedical Sciences, The University of Texas Rio Grande Valley, Edinburg, TX, 78539-2999, USA
| | - Erin Schuenzel
- Department of Biology, The University of Texas Rio Grande Valley, 1201 West University Drive, Edinburg, TX, 78539-2999, USA
| | - Robert Gilkerson
- Department of Biology, The University of Texas Rio Grande Valley, 1201 West University Drive, Edinburg, TX, 78539-2999, USA.
- Department of Clinical Laboratory Sciences, The University of Texas Rio Grande Valley, 1201 West University Drive, Edinburg, TX, 78539-2999, USA.
| |
Collapse
|
42
|
Chambers TP, Santiesteban L, Gomez D, Chambers JW. Sab mediates mitochondrial dysfunction involved in imatinib mesylate-induced cardiotoxicity. Toxicology 2017; 382:24-35. [PMID: 28315715 DOI: 10.1016/j.tox.2017.03.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 02/17/2017] [Accepted: 03/06/2017] [Indexed: 01/05/2023]
Abstract
Imatinib mesylate is an effective treatment for chronic myelogenous leukemia and gastrointestinal stromal tumors. Although imatinib mesylate is highly tolerable, it has been implicated in severe congestive heart failure in mouse models and patients. A hallmark of imatinib mesylate-induced cardiotoxicity is mitochondrial dysfunction. The mitochondrial scaffold Sab has been implicated in facilitating signaling responsible for mitochondrial dysfunction in a c-Jun N-terminal Kinase (JNK)-dependent manner. We examined the impact of Sab-mediated signaling on imatinib mesylate cardiotoxicity in H9c2 rat cardiomyocyte-like cells. Silencing Sab increased the LD50 of imatinib mesylate 4-fold in H9c2 cells. Disrupting Sab-mediated signaling prevented imatinib mesylate-induced apoptosis as well. Knockdown of Sab or inhibition with a small peptide prevented oxidative stress, which was indicated by decreased reactive oxygen species production, lipid peroxidation, and protein carbonylation. Further, inhibition of Sab-related signaling partially rescued deficits in mitochondrial respiration, ATP production, and membrane potential in imatinib mesylate-treated H9c2 cells. Conversely, over-expression of Sab in H9c2 cells increased the cardiotoxicity of imatinib mesylate in vitro decreasing the LD50 over 4-fold. Sab expression was induced in H9c2 cells following cardiovascular-like stress in an AP-1 dependent manner. These data demonstrate that imatinib mesylate influences mitochondrial signaling leading to mitochondrial dysfunction and cardiotoxicity.
Collapse
Affiliation(s)
- Tara P Chambers
- Department of Human and Molecular Genetics, Florida International University, Miami, FL 33199, United States; Herbert Wertheim College of Medicine, Florida International University, Miami, FL 33199, United States
| | - Luis Santiesteban
- Department of Cellular Biology and Pharmacology, Florida International University, Miami, FL 33199, United States
| | - David Gomez
- Department of Cellular Biology and Pharmacology, Florida International University, Miami, FL 33199, United States
| | - Jeremy W Chambers
- Department of Cellular Biology and Pharmacology, Florida International University, Miami, FL 33199, United States; Herbert Wertheim College of Medicine, Florida International University, Miami, FL 33199, United States; Biomolecular Sciences Institute, Florida International University, Miami, FL 33199, United States.
| |
Collapse
|
43
|
Zhang Y, Avalos JL. Traditional and novel tools to probe the mitochondrial metabolism in health and disease. WILEY INTERDISCIPLINARY REVIEWS-SYSTEMS BIOLOGY AND MEDICINE 2017; 9. [PMID: 28067471 DOI: 10.1002/wsbm.1373] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 11/07/2016] [Accepted: 11/09/2016] [Indexed: 02/06/2023]
Abstract
Mitochondrial metabolism links energy production to other essential cellular processes such as signaling, cellular differentiation, and apoptosis. In addition to producing adenosine triphosphate (ATP) as an energy source, mitochondria are responsible for the synthesis of a myriad of important metabolites and cofactors such as tetrahydrofolate, α-ketoacids, steroids, aminolevulinic acid, biotin, lipoic acid, acetyl-CoA, iron-sulfur clusters, heme, and ubiquinone. Furthermore, mitochondria and their metabolism have been implicated in aging and several human diseases, including inherited mitochondrial disorders, cardiac dysfunction, heart failure, neurodegenerative diseases, diabetes, and cancer. Therefore, there is great interest in understanding mitochondrial metabolism and the complex relationship it has with other cellular processes. A large number of studies on mitochondrial metabolism have been conducted in the last 50 years, taking a broad range of approaches. In this review, we summarize and discuss the most commonly used tools that have been used to study different aspects of the metabolism of mitochondria: ranging from dyes that monitor changes in the mitochondrial membrane potential and pharmacological tools to study respiration or ATP synthesis, to more modern tools such as genetically encoded biosensors and trans-omic approaches enabled by recent advances in mass spectrometry, computation, and other technologies. These tools have allowed the large number of studies that have shaped our current understanding of mitochondrial metabolism. WIREs Syst Biol Med 2017, 9:e1373. doi: 10.1002/wsbm.1373 For further resources related to this article, please visit the WIREs website.
Collapse
Affiliation(s)
- Yanfei Zhang
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, USA
| | - José L Avalos
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, USA.,Andlinger Center for Energy and the Environment, Princeton University, Princeton, NJ, USA.,Department of Molecular Biology, Princeton University, Princeton, NJ, USA
| |
Collapse
|
44
|
Srivastava N, Pande M. Mitochondrion: Features, functions and comparative analysis of specific probes in detecting sperm cell damages. ASIAN PACIFIC JOURNAL OF REPRODUCTION 2016. [DOI: 10.1016/j.apjr.2016.10.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
|
45
|
Multiplexed high-content analysis of mitochondrial morphofunction using live-cell microscopy. Nat Protoc 2016; 11:1693-710. [PMID: 27560174 DOI: 10.1038/nprot.2016.094] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Mitochondria have a central role in cellular (patho)physiology, and they display a highly variable morphology that is probably coupled to their functional state. Here we present a protocol that allows unbiased and automated quantification of mitochondrial 'morphofunction' (i.e., morphology and membrane potential), cellular parameters (size, confluence) and nuclear parameters (number, morphology) in intact living primary human skin fibroblasts (PHSFs). Cells are cultured in 96-well plates and stained with tetramethyl rhodamine methyl ester (TMRM), calcein-AM (acetoxy-methyl ester) and Hoechst 33258. Next, multispectral fluorescence images are acquired using automated microscopy and processed to extract 44 descriptors. Subsequently, the descriptor data are subjected to a quality control (QC) algorithm based upon principal component analysis (PCA) and interpreted using univariate, bivariate and multivariate analysis. The protocol requires a time investment of ∼4 h distributed over 2 d. Although it is specifically developed for PHSFs, which are widely used in preclinical research, the protocol is portable to other cell types and can be scaled up for implementation in high-content screening.
Collapse
|
46
|
Maldonado EN, DeHart DN, Patnaik J, Klatt SC, Gooz MB, Lemasters JJ. ATP/ADP Turnover and Import of Glycolytic ATP into Mitochondria in Cancer Cells Is Independent of the Adenine Nucleotide Translocator. J Biol Chem 2016; 291:19642-50. [PMID: 27458020 DOI: 10.1074/jbc.m116.734814] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Indexed: 11/06/2022] Open
Abstract
Non-proliferating cells oxidize respiratory substrates in mitochondria to generate a protonmotive force (Δp) that drives ATP synthesis. The mitochondrial membrane potential (ΔΨ), a component of Δp, drives release of mitochondrial ATP(4-) in exchange for cytosolic ADP(3-) via the electrogenic adenine nucleotide translocator (ANT) located in the mitochondrial inner membrane, which leads to a high cytosolic ATP/ADP ratio up to >100-fold greater than matrix ATP/ADP. In rat hepatocytes, ANT inhibitors, bongkrekic acid (BA), and carboxyatractyloside (CAT), and the F1FO-ATP synthase inhibitor, oligomycin (OLIG), inhibited ureagenesis-induced respiration. However, in several cancer cell lines, OLIG but not BA and CAT inhibited respiration. In hepatocytes, respiratory inhibition did not collapse ΔΨ until OLIG, BA, or CAT was added. Similarly, in cancer cells OLIG and 2-deoxyglucose, a glycolytic inhibitor, depolarized mitochondria after respiratory inhibition, which showed that mitochondrial hydrolysis of glycolytic ATP maintained ΔΨ in the absence of respiration in all cell types studied. However in cancer cells, BA, CAT, and knockdown of the major ANT isoforms, ANT2 and ANT3, did not collapse ΔΨ after respiratory inhibition. These findings indicated that ANT was not mediating mitochondrial ATP/ADP exchange in cancer cells [corrected]. We propose that suppression of ANT contributes to low cytosolic ATP/ADP, activation of glycolysis, and a Warburg metabolic phenotype in proliferating cells.
Collapse
Affiliation(s)
- Eduardo N Maldonado
- From the Center for Cell Death, Injury, and Regeneration, Departments of Drug Discovery and Biomedical Sciences and the Hollings Cancer Center, Medical University of South Carolina, Charleston, South Carolina 29425 and
| | - David N DeHart
- Departments of Drug Discovery and Biomedical Sciences and
| | - Jyoti Patnaik
- Departments of Drug Discovery and Biomedical Sciences and
| | - Sandra C Klatt
- Departments of Drug Discovery and Biomedical Sciences and
| | | | - John J Lemasters
- From the Center for Cell Death, Injury, and Regeneration, Departments of Drug Discovery and Biomedical Sciences and the Hollings Cancer Center, Medical University of South Carolina, Charleston, South Carolina 29425 and Biochemistry and Molecular Biology, and the Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Russian Federation 142290
| |
Collapse
|
47
|
Warne J, Pryce G, Hill JM, Shi X, Lennerås F, Puentes F, Kip M, Hilditch L, Walker P, Simone MI, Chan AWE, Towers GJ, Coker AR, Duchen MR, Szabadkai G, Baker D, Selwood DL. Selective Inhibition of the Mitochondrial Permeability Transition Pore Protects against Neurodegeneration in Experimental Multiple Sclerosis. J Biol Chem 2016; 291:4356-73. [PMID: 26679998 PMCID: PMC4813465 DOI: 10.1074/jbc.m115.700385] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Revised: 12/09/2015] [Indexed: 12/23/2022] Open
Abstract
The mitochondrial permeability transition pore is a recognized drug target for neurodegenerative conditions such as multiple sclerosis and for ischemia-reperfusion injury in the brain and heart. The peptidylprolyl isomerase, cyclophilin D (CypD, PPIF), is a positive regulator of the pore, and genetic down-regulation or knock-out improves outcomes in disease models. Current inhibitors of peptidylprolyl isomerases show no selectivity between the tightly conserved cyclophilin paralogs and exhibit significant off-target effects, immunosuppression, and toxicity. We therefore designed and synthesized a new mitochondrially targeted CypD inhibitor, JW47, using a quinolinium cation tethered to cyclosporine. X-ray analysis was used to validate the design concept, and biological evaluation revealed selective cellular inhibition of CypD and the permeability transition pore with reduced cellular toxicity compared with cyclosporine. In an experimental autoimmune encephalomyelitis disease model of neurodegeneration in multiple sclerosis, JW47 demonstrated significant protection of axons and improved motor assessments with minimal immunosuppression. These findings suggest that selective CypD inhibition may represent a viable therapeutic strategy for MS and identify quinolinium as a mitochondrial targeting group for in vivo use.
Collapse
Affiliation(s)
- Justin Warne
- From the Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Gareth Pryce
- From the Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT, United Kingdom, the Neuroimmunology Unit, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London E1 2AT, United Kingdom
| | - Julia M Hill
- the Department of Cell and Developmental Biology, University College London, London WC1E 6BT, United Kingdom
| | - Xiao Shi
- From the Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Felicia Lennerås
- the Neuroimmunology Unit, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London E1 2AT, United Kingdom
| | - Fabiola Puentes
- the Neuroimmunology Unit, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London E1 2AT, United Kingdom
| | - Maarten Kip
- From the Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Laura Hilditch
- the Medical Research Council Centre for Medical Molecular Biology, Division of Infection and Immunity, University College London, London WC1E 6BT, United Kingdom
| | - Paul Walker
- Cyprotex Discovery Ltd., 100 Barbirolli Square, Manchester M2 3AB, United Kingdom, and
| | - Michela I Simone
- From the Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - A W Edith Chan
- From the Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Greg J Towers
- the Medical Research Council Centre for Medical Molecular Biology, Division of Infection and Immunity, University College London, London WC1E 6BT, United Kingdom
| | - Alun R Coker
- From the Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Michael R Duchen
- the Department of Cell and Developmental Biology, University College London, London WC1E 6BT, United Kingdom
| | - Gyorgy Szabadkai
- the Department of Cell and Developmental Biology, University College London, London WC1E 6BT, United Kingdom, the Department of Biomedical Sciences, University of Padua, Padua 35122, Italy
| | - David Baker
- the Neuroimmunology Unit, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, 4 Newark Street, London E1 2AT, United Kingdom,
| | - David L Selwood
- From the Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT, United Kingdom,
| |
Collapse
|
48
|
Hu J, Ramshesh VK, McGill MR, Jaeschke H, Lemasters JJ. Low Dose Acetaminophen Induces Reversible Mitochondrial Dysfunction Associated with Transient c-Jun N-Terminal Kinase Activation in Mouse Liver. Toxicol Sci 2015; 150:204-15. [PMID: 26721299 DOI: 10.1093/toxsci/kfv319] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Acetaminophen (APAP) overdose causes hepatotoxicity involving mitochondrial dysfunction and c-jun N-terminal kinase (JNK) activation. Because the safe limit of APAP dosing is controversial, our aim was to evaluate the role of the mitochondrial permeability transition (MPT) and JNK in mitochondrial dysfunction after APAP dosing considered nontoxic by criteria of serum alanine aminotransferase (ALT) release and histological necrosis in vivo. C57BL/6 mice were given APAP with and without the MPT inhibitor, N-methyl-4-isoleucine cyclosporin (NIM811), or the JNK inhibitor, SP600125. Fat droplet formation, cell viability, and mitochondrial function in vivo were monitored by intravital multiphoton microscopy. Serum ALT, liver histology, total JNK, and activated phospho(p)JNK were also assessed. High APAP (300 mg/kg) caused ALT release, necrosis, irreversible mitochondrial dysfunction, and hepatocellular death. By contrast, lower APAP (150 mg/kg) caused reversible mitochondrial dysfunction and fat droplet formation in hepatocytes without ALT release or necrosis. Mitochondrial protein N-acetyl-p-benzoquinone imine adducts correlated with early JNK activation, but irreversible mitochondrial depolarization and necrosis at high dose were associated with sustained JNK activation and translocation to mitochondria. NIM811 prevented cell death and/or mitochondrial depolarization after both high and low dose APAP. After low dose, SP600125 decreased mitochondrial depolarization. In conclusion, low dose APAP produces reversible MPT-dependent mitochondrial dysfunction and steatosis in hepatocytes without causing ALT release or necrosis, whereas high dose leads to irreversible mitochondrial dysfunction and cell death associated with sustained JNK activation. Thus, nontoxic APAP has the potential to cause transient mitochondrial dysfunction that may synergize with other stresses to promote liver damage and steatosis.
Collapse
Affiliation(s)
- Jiangting Hu
- *Center for Cell Death, Injury & Regeneration; Departments of Drug Discovery & Biomedical Sciences and Biochemistry & Molecular Biology
| | - Venkat K Ramshesh
- *Center for Cell Death, Injury & Regeneration; Departments of Drug Discovery & Biomedical Sciences and Biochemistry & Molecular Biology; Hollings Cancer Center, Medical University of South Carolina, Charleston, South Carolina 29425
| | - Mitchell R McGill
- Department of Pharmacology, Toxicology & Therapeutics, University of Kansas Medical Center, Kansas City, Kansas 66160; and
| | - Hartmut Jaeschke
- Department of Pharmacology, Toxicology & Therapeutics, University of Kansas Medical Center, Kansas City, Kansas 66160; and
| | - John J Lemasters
- *Center for Cell Death, Injury & Regeneration; Departments of Drug Discovery & Biomedical Sciences and Biochemistry & Molecular Biology; Hollings Cancer Center, Medical University of South Carolina, Charleston, South Carolina 29425; Institute of Theoretical & Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region 142290, Russian Federation
| |
Collapse
|
49
|
da Costa RFM, Kormann ML, Galina A, Rehen SK. Valproate Disturbs Morphology and Mitochondrial Membrane Potential in Human Neural Cells. ACTA ACUST UNITED AC 2015. [DOI: 10.1089/aivt.2015.0016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
| | - Michelle Louise Kormann
- D'Or Institute for Research and Education, Rio de Janeiro, Brazil
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Antonio Galina
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Stevens Kastrup Rehen
- D'Or Institute for Research and Education, Rio de Janeiro, Brazil
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| |
Collapse
|
50
|
Jhaveri A, Torchilin V. Intracellular delivery of nanocarriers and targeting to subcellular organelles. Expert Opin Drug Deliv 2015; 13:49-70. [DOI: 10.1517/17425247.2015.1086745] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|