scholarly journals Discovery of bactericides as an acute mitochondrial membrane damage inducer

2021 ◽  
pp. mbc.E21-04-0191
Author(s):  
Ryan Houston ◽  
Yusuke Sekine ◽  
Mads B Larsen ◽  
Kei Murakami ◽  
Steven J Mullett ◽  
...  
Keyword(s):  
Stress Responses ◽  
Mitochondrial Membrane ◽  
Membrane Damage ◽  
Membrane Integrity ◽  
Microscopic Analysis ◽  
Mitochondrial Membranes ◽  
Inner Mitochondrial Membrane ◽  
Electron Microscopic ◽  
Bacterial Membranes ◽  
Anionic Phospholipids

Mitochondria evolved from endosymbiotic bacteria to become essential organelles of eukaryotic cells. The unique lipid composition and structure of mitochondrial membranes are critical for the proper functioning of mitochondria. However, stress responses that help maintain the mitochondrial membrane integrity are not well understood. One reason for this lack of insight is the absence of efficient tools to specifically damage mitochondrial membranes. Here, through a compound screen, we found that two bis-biguanide compounds, Chlorhexidine and Alexidine, modified the activity of the inner mitochondrial membrane (IMM)-resident protease OMA1 by altering the integrity of the IMM. These compounds are well-known bactericides whose mechanism of action has centered on their damage-inducing activity on bacterial membranes. We found Alexidine binds to the IMM likely through the electrostatic interaction driven by the membrane potential as well as an affinity for anionic phospholipids. Electron microscopic analysis revealed that Alexidine severely perturbated the cristae structure. Notably, Alexidine evoked a specific transcriptional/proteostasis signature that was not induced by other typical mitochondrial stressors, highlighting the unique property of Alexidine as a novel mitochondrial membrane stressor. Our findings provide a chemical-biological tool that should enable the delineation of mitochondrial stress-signaling pathways required to maintain the mitochondrial membrane homeostasis.

scholarly journals Discovery of bactericides as an acute mitochondrial membrane damage inducer

2021 ◽  
Author(s):  
Ryan Houston ◽  
Yusuke Sekine ◽  
Mads B Larsen ◽  
Kei Murakami ◽  
Derek P Narendra ◽  
...  
Keyword(s):  
Stress Responses ◽  
Mitochondrial Membrane ◽  
Membrane Damage ◽  
Microscopic Analysis ◽  
Mitochondrial Membranes ◽  
Inner Mitochondrial Membrane ◽  
Electron Microscopic ◽  
Mitochondrial Stress ◽  
Bacterial Membranes ◽  
Anionic Phospholipids

Mitochondria evolved from endosymbiotic bacteria to become essential organelles of eukaryotic cells. The defined lipid composition and structure of mitochondrial membranes are critical for the proper functioning of mitochondria. However, mitochondrial stress responses that help maintain the integrity of mitochondrial membranes against internal or external insults are not well understood. One reason for this lack of insight is the absence of efficient tools to specifically damage mitochondrial membranes. Here, through a compound screen originally aimed at identifying inhibitors of the inner mitochondrial membrane (IMM)-resident protease OMA1, we found that two bis-biguanide compounds, Chlorhexidine and Alexidine, modified OMA1 activity by altering the integrity of the IMM. Interestingly, these compounds are well-known bactericides whose mechanism of action has centered on their damage-inducing activity on bacterial membranes. We found Alexidine binds to the IMM likely through the electrostatic interaction driven by the membrane potential as well as an affinity for anionic phospholipids. Electron microscopic analysis revealed that Alexidine severely perturbated the IMM, especially the cristae structure. Along with this, we observed the altered localization of IMM-resident membrane-shaping proteins, including Mic60. Notably, Alexidine evoked a specific transcriptional/proteostasis signature that was not induced by other typical mitochondrial stressors, highlighting the unique property of Alexidine as a novel mitochondrial membrane stressor. Our findings provide a chemical-biological tool that can induce acute and selective perturbation of the IMM integrity, which should enable the delineation of mitochondrial stress-signaling pathways required to maintain the mitochondrial membrane homeostasis.

scholarly journals Morphofunctional effects of mitotane on mitochondria in human adrenocortical cancer cells

2013 ◽  
Vol 20 (4) ◽  
pp. 537-550 ◽  
Author(s):  
Giada Poli ◽  
Daniele Guasti ◽  
Elena Rapizzi ◽  
Rossella Fucci ◽  
Letizia Canu ◽  
...  
Keyword(s):  
Toxic Effect ◽  
Mitochondrial Membrane ◽  
Membrane Damage ◽  
Clinical Signs ◽  
Microscopic Analysis ◽  
Therapeutic Window ◽  
Mitochondrial Morphology ◽  
Adrenocortical Cancer ◽  
Electron Microscopic ◽  
Cytotoxic Effects

At present, mitotane (MTT) represents the first-line pharmacological approach for the treatment of advanced adrenocortical carcinoma (ACC). Despite clear evidence that the drug can reduce the clinical signs of steroid excess in secreting ACC, the mechanism mediating the possible toxic effect of MTT on tumor cells still remains obscure. This study investigated the intracellular events underlying the toxic effect of MTT by studying qualitative and quantitative alterations in mitochondrial morphology and functions in human adrenocortical cancer cell lines, H295R and SW13. Increasing concentrations of MTT resulted in rapid intracellular accumulation and conversion of the drug. Cytostatic and cytotoxic effects were evident at doses corresponding to the therapeutic window (30–50 μM) through an apoptotic mechanism involving caspase 3/7. Electron microscopic analysis of cell mitochondria displayed MTT-induced dose- and time-dependent alterations in the morphology of the organelle. These alterations were characterized by a marked swelling and a decrease in the number of respiratory cristae, accompanied by a significant depolarization of the mitochondrial membrane potential, finally leading to the disruption of the organelle. A drastic reduction of oxygen consumption was observed due to mitochondrial membrane damage, which was accompanied by a decrease in the levels of VDAC1 integral membrane channel. These findings contribute to better understand the intracellular mechanism of action of MTT in ACC cells, showing that its cytotoxic effect seems to be mainly mediated by an apoptotic process activated by the disruption of mitochondria.

scholarly journals Molecular mechanism of mitochondrial phosphatidate transfer by Ups1

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Jiuwei Lu ◽  
Chun Chan ◽  
Leiye Yu ◽  
Jun Fan ◽  
Fei Sun ◽  
...  
Keyword(s):  
Conformational Changes ◽  
Mitochondrial Membrane ◽  
Outer Mitochondrial Membrane ◽  
Mitochondrial Membranes ◽  
Inner Mitochondrial Membrane ◽  
Membrane Interaction ◽  
Detailed Mechanism ◽  
Physiological Regulator ◽  
Membrane Bound ◽  
Dynamics Simulations

AbstractCardiolipin, an essential mitochondrial physiological regulator, is synthesized from phosphatidic acid (PA) in the inner mitochondrial membrane (IMM). PA is synthesized in the endoplasmic reticulum and transferred to the IMM via the outer mitochondrial membrane (OMM) under mediation by the Ups1/Mdm35 protein family. Despite the availability of numerous crystal structures, the detailed mechanism underlying PA transfer between mitochondrial membranes remains unclear. Here, a model of Ups1/Mdm35-membrane interaction is established using combined crystallographic data, all-atom molecular dynamics simulations, extensive structural comparisons, and biophysical assays. The α2-loop, L2-loop, and α3 helix of Ups1 mediate membrane interactions. Moreover, non-complexed Ups1 on membranes is found to be a key transition state for PA transfer. The membrane-bound non-complexed Ups1/ membrane-bound Ups1 ratio, which can be regulated by environmental pH, is inversely correlated with the PA transfer activity of Ups1/Mdm35. These results demonstrate a new model of the fine conformational changes of Ups1/Mdm35 during PA transfer.

scholarly journals Histochemical localization of trehalase activity in dorsal flight muscle of the flesh fly Sarcophaga bullata with light and electron microscopy.

1975 ◽  
Vol 23 (11) ◽  
pp. 800-807 ◽  
Author(s):  
P L Chang ◽  
P E Morrison
Keyword(s):  
Electron Microscopy ◽  
Incubation Medium ◽  
Mitochondrial Membrane ◽  
Flight Muscle ◽  
Light And Electron Microscopy ◽  
Inner Mitochondrial Membrane ◽  
Electron Microscopic ◽  
Flesh Fly ◽  
Trehalase Activity ◽  
Sarcophaga Bullata

Trehalase activity in flight muscle of the flesh fly Sacrophaga bullata is detected histochemically at light- and electron-microscopic levels by using diaminobenzidine, glucose oxidase and peroxidase in the incubation medium. The association of trehalase activity with the inner mitochondrial membrane is confirmed. Biochemical assay shows that about 50% of the initial total trehalase activity is lost from the tissue during the histochemical processing and about 50% remains for histochemical detection.

scholarly journals Stilbene derivatives inhibit the activity of the inner mitochondrial membrane chloride channels

2007 ◽  
Vol 12 (4) ◽  
Author(s):  
Izabela Koszela-Piotrowska ◽  
Katarzyna Choma ◽  
Piotr Bednarczyk ◽  
Krzysztof Dołowy ◽  
Adam Szewczyk ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Chloride Channel ◽  
Chloride Channels ◽  
Mitochondrial Membrane ◽  
Disulfonic Acid ◽  
Mitochondrial Membranes ◽  
Rat Skeletal Muscle ◽  
Inner Mitochondrial Membrane ◽  
Stilbene Derivatives ◽  
Rat Heart Mitochondria

AbstractIon channels selective for chloride ions are present in all biological membranes, where they regulate the cell volume or membrane potential. Various chloride channels from mitochondrial membranes have been described in recent years. The aim of our study was to characterize the effect of stilbene derivatives on single-chloride channel activity in the inner mitochondrial membrane. The measurements were performed after the reconstitution into a planar lipid bilayer of the inner mitochondrial membranes from rat skeletal muscle (SMM), rat brain (BM) and heart (HM) mitochondria. After incorporation in a symmetric 450/450 mM KCl solution (cis/trans), the chloride channels were recorded with a mean conductance of 155 ± 5 pS (rat skeletal muscle) and 120 ± 16 pS (rat brain). The conductances of the chloride channels from the rat heart mitochondria in 250/50 mM KCl (cis/trans) gradient solutions were within the 70–130 pS range. The chloride channels were inhibited by these two stilbene derivatives: 4,4′-diisothiocyanostilbene-2,2′-disulfonic acid (DIDS) and 4-acetamido-4′-isothiocyanostilbene-2,2′-disulfonic acid (SITS). The skeletal muscle mitochondrial chloride channel was blocked after the addition of 1 mM DIDS or SITS, whereas the brain mitochondrial channel was blocked by 300 μM DIDS or SITS. The chloride channel from the rat heart mitochondria was inhibited by 50–100 μM DIDS. The inhibitory effect of DIDS was irreversible. Our results confirm the presence of chloride channels sensitive to stilbene derivatives in the inner mitochondrial membrane from rat skeletal muscle, brain and heart cells.

scholarly journals Cardiolipin, Non-Bilayer Structures and Mitochondrial Bioenergetics: Relevance to Cardiovascular Disease

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1721
Author(s):  
Edward S. Gasanoff ◽  
Lev S. Yaguzhinsky ◽  
Győző Garab
Keyword(s):  
Electron Transport Chain ◽  
Mitochondrial Membrane ◽  
Mitochondrial Bioenergetics ◽  
Mitochondrial Membranes ◽  
Inner Mitochondrial Membrane ◽  
Atp Production ◽  
Functional Roles ◽  
Transport Chain ◽  
Energy Converting

The present review is an attempt to conceptualize a contemporary understanding about the roles that cardiolipin, a mitochondrial specific conical phospholipid, and non-bilayer structures, predominantly found in the inner mitochondrial membrane (IMM), play in mitochondrial bioenergetics. This review outlines the link between changes in mitochondrial cardiolipin concentration and changes in mitochondrial bioenergetics, including changes in the IMM curvature and surface area, cristae density and architecture, efficiency of electron transport chain (ETC), interaction of ETC proteins, oligomerization of respiratory complexes, and mitochondrial ATP production. A relationship between cardiolipin decline in IMM and mitochondrial dysfunction leading to various diseases, including cardiovascular diseases, is thoroughly presented. Particular attention is paid to the targeting of cardiolipin by Szeto–Schiller tetrapeptides, which leads to rejuvenation of important mitochondrial activities in dysfunctional and aging mitochondria. The role of cardiolipin in triggering non-bilayer structures and the functional roles of non-bilayer structures in energy-converting membranes are reviewed. The latest studies on non-bilayer structures induced by cobra venom peptides are examined in model and mitochondrial membranes, including studies on how non-bilayer structures modulate mitochondrial activities. A mechanism by which non-bilayer compartments are formed in the apex of cristae and by which non-bilayer compartments facilitate ATP synthase dimerization and ATP production is also presented.

scholarly journals The distribution of anionic sites on the surfaces of mitochondrial membranes. Visual probing with polycationic ferritin.

1975 ◽  
Vol 65 (3) ◽  
pp. 615-630 ◽  
Author(s):  
C R Hackenbrock ◽  
K J Miller
Keyword(s):  
Outer Membrane ◽  
Mitochondrial Membrane ◽  
High Density ◽  
Intermembrane Space ◽  
Mitochondrial Membranes ◽  
Inner Mitochondrial Membrane ◽  
Anionic Sites ◽  
Contact Sites ◽  
Intact Mitochondrion ◽  
Boundary Membrane

Polycationic ferritin, a multivalent ligand, was used as a visual probe to determine the distribution and density of anionic sites on the surfaces of rat liver mitochondrial membranes. Both the distribution of bound polycationic ferritin and the topography of the outer surface of the inner mitochondrial membrane were studied in depth by utilizing thin sections and critical-point dried, whole mount preparations for transmission electron microscopy and by scanning electron microscopy. Based on its relative affinity for polycationic ferritin, the surface of the inner membrane contains discrete regions of high density and low density anionic sites. Whereas the surface of the cristal membrane contains a low density of anionic sites, the surface of the inner boundary membrane contains patches of high density anionic sites. The high density anionic sites on the inner boundary membrane were found to persist as stable patches and did not dissociate or randomize freely when the membrane was converted osmotically to a spherical configuration. The observations suggest that the inner mitochondrial membrane is composed of two major regions of anionic macromolecular distinction. It is well-known that an intermembrane space exists between the two membranes of the intact mitochondrion; however, a number of contact sites occur between the two membranes. We determined that the outer membrane, partially disrupted by treatment with digitonin, remains attached to the inner membrane at these contact sites as inverted vesicles. Such attached vesicles show that the inner surface of the outer membrane contains anionic sites, but of decreased density, surrounding the contact sites. Thus, the intermembrane space in the intact mitochondrion may be maintained by electronegative surfaces of the two mitochondrial membranes. The distribution of anionic sites on the outer surface of the outer membrane is random. The nature and function of fixed anionic surface charges and membrane contact sites are discussed with regard to recent reports relating to calcium transport, protein assembly into mitochondrial membranes, and membrane fluidity.

scholarly journals Antibacterial and Biofilm Modulating Potential of Ferulic Acid Grafted Chitosan against Human Pathogenic Bacteria

2018 ◽  
Author(s):  
Chakradhar Dasagrandhi ◽  
Seulki Park ◽  
Won-Kyo Jung ◽  
Young-Mog Kim
Keyword(s):  
Ferulic Acid ◽  
Bacterial Infections ◽  
Pathogenic Bacteria ◽  
Membrane Integrity ◽  
Microscopic Analysis ◽  
Multi Drug Resistance ◽  
Bactericidal Action ◽  
Electron Microscopic ◽  
Iodide Uptake ◽  
Human Pathogenic Bacteria

Emergence of more virulent forms of human pathogenic bacteria with multi drug resistance is a serious global issue and requires alternative control strategies. The current study was focused to investigate the antibacterial and antibiofilm potential of ferulic acid grafted chitosan (CFA) against Listeria monocytogenes (LM), Pseudomonas aeruginosa (PA), and Staphylococcus aureus (SA). The present result showed that CFA at 64 µg/mL concentration exhibit bactericidal action against LM and SA (>4 log reduction) and bacteriostatic action against PA (<2 log CFU) within 24 h of incubation. Further studies based on propidium iodide uptake assay, measurement of material released from the cell, and electron microscopic analysis revealed that the bactericidal action of CFA was due to the altered membrane integrity and permeability. CFA dose-dependently inhibited biofilm formation (52-89% range), its metabolic activity (30.8-75.1% range) and eradicated mature biofilms, and reduced viability (71-82% range) of the test bacteria. Also, the swarming motility of LM was differentially affected at sub-MIC concentration of CFA. In the present study, the ability of CFA to kill and alter the virulence production in human pathogenic bacteria will insight a new scope for the application of these biomaterials in healthcare to effectively treat bacterial infections.

scholarly journals OMA1 mediates local and global stress responses against protein misfolding in CHCHD10 mitochondrial myopathy

2021 ◽  
Author(s):  
Mario K. Shammas ◽  
Xiaoping Huang ◽  
Beverly P. Wu ◽  
Insung Song ◽  
Nicholas Randolph ◽  
...  
Keyword(s):  
Stress Response ◽  
Stress Responses ◽  
Protein Misfolding ◽  
Mitochondrial Membrane ◽  
Mitochondrial Protein ◽  
Inner Mitochondrial Membrane ◽  
Disease Etiology ◽  
Transport Chain ◽  
Global Stress

Mitochondrial stress triggers a response in the cell's mitochondria and nucleus, but how these stress responses are coordinated in vivo is poorly understood. Here, we characterize a family with myopathy caused by a dominant p.G58R mutation in the mitochondrial protein CHCHD10. To understand the disease etiology, we developed a novel knock-in mouse model and found that mutant CHCHD10 aggregates in affected tissues, applying a toxic protein stress to the inner mitochondrial membrane. Unexpectedly, survival of CHCHD10 knock-in mice depended on a protective stress response mediated by OMA1. The OMA1 stress response acted both locally within mitochondria, inhibiting mitochondrial fusion, and signaled outside the mitochondria, activating the integrated stress response. We additionally identified an isoform switch in the terminal complex of the electron transport chain as a novel component of this response. Our results demonstrate that OMA1 is essential for neonatal survival conditionally in the setting of inner mitochondrial membrane stress, coordinating local and global stress responses to reshape the mitochondrial network and proteome.

Rhabdomyolysis secondary to lovastatin therapy

1990 ◽  
Vol 36 (12) ◽  
pp. 2145-2147 ◽  
Author(s):  
A A Manoukian ◽  
N V Bhagavan ◽  
T Hayashi ◽  
T A Nestor ◽  
C Rios ◽  
...  
Keyword(s):  
Mitochondrial Membrane ◽  
Adverse Reactions ◽  
Clinical Course ◽  
Coenzyme Q ◽  
Serum Creatine Kinase ◽  
Clinical Settings ◽  
Inner Mitochondrial Membrane ◽  
Electron Microscopic ◽  
Microscopic Studies ◽  
Life Threatening

Abstract We report a case of lovastatin-induced rhabdomyolysis and resulting life-threatening renal failure. Lovastatin, a hypocholesterolemic agent, decreases endogenous cholesterol synthesis by inhibiting 3-hydroxy-3-methylglutaryl coenzyme A reductase (EC 1.1.1.88). This agent has been implicated in causing rare serious side effects in various clinical settings; however, the mechanism of these adverse reactions is not understood. The clinical course of our patient was characterized by profound muscle weakness with marked increases in serum creatine kinase and myoglobin. Light- and electron-microscopic studies of skeletal muscle of our patient demonstrated a noninflammatory myopathy suggestive of ongoing rhabdomyolysis with vacuolization and focal degeneration of myocytes. The patient's symptoms and the laboratory values referable to rhabdomyolysis resolved after discontinuation of the drug. We speculate that the rhabdomyolysis was due to mitochondrial damage secondary to inadequate synthesis of coenzyme Q and heme A, members of the electron-transport system of the inner mitochondrial membrane.

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