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Toxicology Mechanisms and Methods Feb 2022Mitochondria have the main roles in myocardial tissue homeostasis, through providing ATP for the vital enzymes in intermediate metabolism, contractile apparatus and...
Mitochondria have the main roles in myocardial tissue homeostasis, through providing ATP for the vital enzymes in intermediate metabolism, contractile apparatus and maintaining ion homeostasis. Mitochondria-related cardiotoxicity results from the exposure with illicit drugs have previously reported. These illicit drugs interference with processes of normal mitochondrial homeostasis and lead to mitochondrial dysfunction and mitochondrial-related oxidative stress. Cannabis consumption has been shown to cause ventricular tachycardia, to increase the risk of myocardial infarction (MI) and potentially sudden death. Here, we investigated this hypothesis that delta-9-tetrahydrocannabinol (Delta-9-THC) as a main cannabinoid found in cannabis could directly cause mitochondrial dysfunction. Cardiac mitochondria were isolated with mechanical lysis and differential centrifugation form rat heart. The isolated cardiac mitochondria were treated with different concentrations of THC (1, 5, 10, 50, 100 and 500 µM) for 1 hour at 37 °C. Then, succinate dehydrogenase (SDH) activity, mitochondrial swelling, reactive oxygen species (ROS) formation, mitochondrial membrane potential (MMP) collapse and lipid peroxidation were measured in the treated and nontreated isolated cardiac mitochondria. Our observation showed that THC did not cause a deleterious alteration in mitochondrial functions, ROS production, MMP collapse, mitochondrial swelling, oxidative stress and lipid peroxidation in used concentrations (5-100 µM), even in several tests, toxicity showed a decreasing trend. Altogether, the results of the current study showed that THC is not directly toxic in isolated cardiac mitochondria, and even may be helpful in reducing mitochondrial toxicity.
Topics: Animals; Dronabinol; Membrane Potential, Mitochondrial; Mitochondria, Heart; Mitochondrial Swelling; Oxidative Stress; Rats; Reactive Oxygen Species
PubMed: 34431445
DOI: 10.1080/15376516.2021.1973168 -
Biomedical Optics Express Nov 2015Mitochondria play a key role in all cellular physiology, processes, and behaviors. It is very difficult to precisely stimulate single mitochondria noninvasively in...
Mitochondria play a key role in all cellular physiology, processes, and behaviors. It is very difficult to precisely stimulate single mitochondria noninvasively in traditional biomedical research. In this study, we report that femtosecond laser can stimulate fragmentation or swelling of single mitochondria in human mesenchymal stem cells rather than physical disruption or ablation. In experiments, fragmented mitochondria can recover normal very soon but swelling ones cannot. At the same time, laser-induced generation of mitochondrial reactive oxygen species and opening of mitochondria permeability transition pores are involved in mitochondrial responses to photostimulation. Furthermore, the localized translocation of proapoptotic molecules are found in those stimulated mitochondria. Those results suggest femtosecond-laser photostimulation as a noninvasive and precise method for mitochondrial manipulation and related research.
PubMed: 26601016
DOI: 10.1364/BOE.6.004539 -
Oral Diseases Sep 2019Mitophagy is an important mitochondrial quality control mechanism. In this study, we investigated the mitochondrial damage and mitophagy occurred in inflammatory human...
OBJECTIVES
Mitophagy is an important mitochondrial quality control mechanism. In this study, we investigated the mitochondrial damage and mitophagy occurred in inflammatory human dental pulp and lipopolysaccharide-stimulated preodontoblasts.
MATERIALS AND METHODS
In dental pulp tissues and lipopolysaccharide-stimulated preodontoblasts, immunofluorescences and Western blot were performed to detect the expression of mitochondrial and mitophagy-related proteins, and autophagy markers were also examined. Reactive oxygen species generated by mitochondria were examined by MitoSOX. Transmission electron microscope (TEM) was used to examine the morphology of mitochondria in lipopolysaccharide-stimulated preodontoblasts.
RESULTS
The active fission activity of mitochondria and mitophagy in inflammatory dental pulp was observed. In lipopolysaccharide-treated preodontoblasts, mitophagy-related proteins were also upregulated. Moreover, increased reactive oxygen species in the inflamed preodontoblasts were observed. Additionally, single-membrane autolysosomes containing partially degraded mitochondria with swollen inner membranes in lipopolysaccharide-treated preodontoblasts were observed by TEM.
CONCLUSIONS
These results indicate that mitochondria were damaged and mitophagy might be activated to degrade impaired mitochondria in inflamed odontoblasts.
Topics: Humans; Mitochondria; Mitochondrial Swelling; Mitophagy; Odontoblasts; Protein Kinases; Ubiquitin-Protein Ligases
PubMed: 31009146
DOI: 10.1111/odi.13110 -
Methods in Molecular Biology (Clifton,... 2015Maintenance of mitochondrial membrane integrity is essential for mitochondrial function and neuronal viability. Apoptotic stimulus or calcium overload leads to...
Maintenance of mitochondrial membrane integrity is essential for mitochondrial function and neuronal viability. Apoptotic stimulus or calcium overload leads to mitochondrial permeability transition pore (mPTP ) opening and induces mitochondrial swelling, a common feature of mitochondrial membrane permeabilization. The first phenomenon can be evaluated in cells loaded with the dye calcein -AM quenched by cobalt, and mitochondrial swelling can be detected by electron microscopy through the analysis of mitochondrial membrane integrity. Here, we describe a live cell imaging assay to detect mitochondrial permeability transition and the development of a detailed analysis of morphological and ultrastructural changes that mitochondria undergo during this process.
Topics: Calcium; Microscopy, Electron; Mitochondria; Mitochondrial Membrane Transport Proteins; Mitochondrial Membranes; Mitochondrial Permeability Transition Pore; Mitochondrial Swelling; Molecular Biology; Neurons; Permeability
PubMed: 25431059
DOI: 10.1007/978-1-4939-2152-2_7 -
Basic Research in Cardiology Jun 2024Mitochondrial calcium (Ca) signals play a central role in cardiac homeostasis and disease. In the healthy heart, mitochondrial Ca levels modulate the rate of oxidative... (Review)
Review
Mitochondrial calcium (Ca) signals play a central role in cardiac homeostasis and disease. In the healthy heart, mitochondrial Ca levels modulate the rate of oxidative metabolism to match the rate of adenosine triphosphate consumption in the cytosol. During ischemia/reperfusion (I/R) injury, pathologically high levels of Ca in the mitochondrial matrix trigger the opening of the mitochondrial permeability transition pore, which releases solutes and small proteins from the matrix, causing mitochondrial swelling and ultimately leading to cell death. Pharmacological and genetic approaches to tune mitochondrial Ca handling by regulating the activity of the main Ca influx and efflux pathways, i.e., the mitochondrial Ca uniporter and sodium/Ca exchanger, represent promising therapeutic strategies to protect the heart from I/R injury.
PubMed: 38890208
DOI: 10.1007/s00395-024-01060-2 -
Canadian Journal of Physiology and... Sep 2019Age and sex play an essential role in the cardiac tolerance to ischemia-reperfusion injury: cardiac resistance significantly decreases during postnatal maturation and... (Review)
Review
Age and sex play an essential role in the cardiac tolerance to ischemia-reperfusion injury: cardiac resistance significantly decreases during postnatal maturation and the female heart is more tolerant than the male myocardium. It is widely accepted that mitochondrial dysfunction, and particularly mitochondrial permeability transition pore (MPTP) opening, plays a major role in determining the extent of cardiac ischemia-reperfusion injury. We have observed that the MPTP sensitivity to the calcium load differs in mitochondria isolated from neonatal and adult myocardium, as well as from adult male and female hearts. Neonatal and female mitochondria are more resistant both in the extent and in the rate of mitochondrial swelling induced by high calcium concentration. Our data further suggest that age- and sex-dependent specificity of the MPTP is not the result of different amounts of ATP synthase and cyclophilin D: neonatal and adult hearts, similarly as the male and female hearts, contain comparable amounts of MPTP and its regulatory protein cyclophilin D. We can speculate that the lower sensitivity of MPTP to the calcium-induced swelling may be related to the higher ischemic tolerance of both neonatal and female myocardium.
Topics: Animals; Calcium; Heart; Humans; Mitochondria, Heart; Mitochondrial Membrane Transport Proteins; Mitochondrial Permeability Transition Pore; Myocardial Reperfusion Injury; Sex Characteristics
PubMed: 30893574
DOI: 10.1139/cjpp-2019-0060 -
Naunyn-Schmiedeberg's Archives of... Aug 2021The generation of a reactive nitrenium ion by microsomal/mitochondrial cytochrome P450 (CYPs) from clozapine (CLZ) has been suggested as the main cause of cardiotoxicity...
The generation of a reactive nitrenium ion by microsomal/mitochondrial cytochrome P450 (CYPs) from clozapine (CLZ) has been suggested as the main cause of cardiotoxicity by this drug. Previous studies indicated that thymoquinone (TQ) as an active constituent of Nigella sativa has pharmacological effects such as antioxidant, reactive oxygen species (ROS) scavenger, and inhibitory effect on CYPs enzymes. Therefore, we hypothesized that TQ with these pharmacological effects can reduce CLZ-induced toxicity in isolated cardiomyocytes and mitochondria. Rat left ventricular cardiomyocytes and mitochondria were isolated by collagenase perfusion and differential centrifugation respectively. Then, isolated cardiomyocytes and mitochondria were pretreated with different concentrations of TQ (1, 5, and 10 μmol/l) for 30 min and then followed by exposure to CLZ (50 μmol/l) for 6 h. After 6 h of incubation, using biochemical evaluations and flow cytometric analysis, the parameters of cellular toxicity including cytotoxicity, the level of oxidized/reduced glutathione (GSH/GSSG), malondialdehyde (MDA), reactive oxygen species (ROS) formation, lysosomal membrane integrity, mitochondria membrane potential (ΔΨm) collapse, and mitochondrial toxicity including succinate dehydrogenase (SDH) activity and mitochondrial swelling were analyzed. We observed a significant toxicity in isolated cardiomyocytes and mitochondria after exposure with CLZ which was related to ROS formation, oxidative stress, GSH depletion, lysosomal and mitochondrial damages, and mitochondrial dysfunction and swelling, while TQ pretreatment reverted the above toxic effect of CLZ on isolated cardiomyocytes and mitochondria. Our results indicate that TQ prevents and reverses CLZ-induced cytotoxicity and mitochondrial damages in isolated cardiomyocytes and mitochondria, providing an experimental basis for clinical treatment on CLZ-induced cardiotoxicity.
Topics: Animals; Antipsychotic Agents; Benzoquinones; Cardiotoxicity; Cell Death; Clozapine; Dose-Response Relationship, Drug; Glutathione; Male; Malondialdehyde; Membrane Potential, Mitochondrial; Mitochondria, Heart; Mitochondrial Swelling; Myocytes, Cardiac; Oxidative Stress; Rats; Rats, Wistar; Reactive Oxygen Species
PubMed: 33937934
DOI: 10.1007/s00210-021-02095-1 -
Clinical Science (London, England :... Apr 2020Mitochondria are dynamic, undergoing both fission and fusion. Evidence indicates that a balance between these two processes is necessary to maintain a healthy state....
Mitochondria are dynamic, undergoing both fission and fusion. Evidence indicates that a balance between these two processes is necessary to maintain a healthy state. With ischemia/reperfusion (I/R) of the heart, fission is enhanced and is associated with mitochondrial swelling, depolarization, and production of reactive oxygen species (ROS), as well as apoptosis. Blocking fission is effective in reducing I/R-induced tissue damage and contractile dysfunction. In a groundbreaking study appearing in Clinical Science, Maneechote et al. assessed whether correcting the imbalance in mitochondrial dynamics with I/R by enhancing fusion would also be protective. Using a rat model, they investigated the efficacy of pharmacological intervention with mitochondrial fusion promoter-M1 (M1) given before ischemia, during ischemia, or at the onset of reperfusion. With pretreatment being the most effective, they found that M1 attenuated the incidence of arrhythmias, reduced infarct size, preserved cardiac function, and decreased mortality. M1 reduced I/R-induced increases in cytosolic cytochrome c, cleaved caspase 3, and apoptosis. All M1 groups exhibited modestly attenuated I/R-induced mitochondrial ROS levels and swelling, and preserved mitochondrial membrane potential. M1 also prevented a decrease in complex V levels with I/R. However, exactly how M1 stimulates mitochondrial fusion is unclear and other nonfusion-related actions of this phenylhydrazone compound should be considered, such as anti-oxidant actions, preconditioning signaling, or effects on putative mitochondrial connexin 43.
Topics: Animals; Apoptosis; Mitochondria; Mitochondrial Dynamics; Myocardial Infarction; Myocardial Reperfusion Injury; Rats; Reactive Oxygen Species; Ventricular Dysfunction, Left
PubMed: 32286622
DOI: 10.1042/CS20200236 -
Cell Death & Disease Jul 2019Noxa, a Bcl-2 homology 3 (BH3)-only protein of the Bcl-2 family, is responsive to cell stresses and triggers apoptosis by binding the prosurvival Bcl-2-like proteins...
Noxa, a Bcl-2 homology 3 (BH3)-only protein of the Bcl-2 family, is responsive to cell stresses and triggers apoptosis by binding the prosurvival Bcl-2-like proteins Mcl1, Bcl, and Bcl2A1. Although the Noxa BH3 domain is necessary to induce apoptosis, the mitochondrial targeting domain (MTD) of Noxa functions as a pronecrotic domain, an inducer of mitochondrial fragmentation, and delivery to mitochondria. In this study, we demonstrate that the extended MTD (eMTD) peptide induces necrotic cell death by interaction with the VDAC2 protein. The eMTD peptide penetrates the cell membrane, causing cell membrane blebbing, cytosolic calcium influx, and mitochondrial swelling, fragmentation, and ROS generation. The MTD domain binds VDACs and opens the mitochondrial permeability transition pore (mPTP) in a CypD-independent manner. The opening of mPTP induced by eMTD is inhibited either by down-regulation of VDAC2 or by the VDACs inhibitor DIDS. These results indicate that the MTD domain of Noxa causes mitochondrial damage by opening mPTP through VDACs, especially VDAC2, during necrotic cell death.
Topics: Amino Acid Sequence; Animals; Calcium; Cell Membrane; Cytosol; HEK293 Cells; HeLa Cells; Humans; Mice, Inbred BALB C; Mitochondria; Mitochondrial Membrane Transport Proteins; Mitochondrial Permeability Transition Pore; Mitochondrial Swelling; Necrosis; Protein Binding; Protein Domains; Proto-Oncogene Proteins c-bcl-2; Reactive Oxygen Species; Structure-Activity Relationship; Voltage-Dependent Anion Channel 2
PubMed: 31285435
DOI: 10.1038/s41419-019-1753-4 -
Neural Regeneration Research Apr 2023The mitochondrial permeability transition pore is a nonspecific transmembrane channel. Inhibition of mitochondrial permeability transition pore opening has been shown to...
The mitochondrial permeability transition pore is a nonspecific transmembrane channel. Inhibition of mitochondrial permeability transition pore opening has been shown to alleviate mitochondrial swelling, calcium overload, and axonal degeneration. Cyclophilin D is an important component of the mitochondrial permeability transition pore. Whether cyclophilin D participates in mitochondrial impairment and axonal injury after intracerebral hemorrhage is not clear. In this study, we established mouse models of intracerebral hemorrhage in vivo by injection of autologous blood and oxyhemoglobin into the striatum in Thy1-YFP mice, in which pyramidal neurons and axons express yellow fluorescent protein. We also simulated intracerebral hemorrhage in vitro in PC12 cells using oxyhemoglobin. We found that axonal degeneration in the early stage of intracerebral hemorrhage depended on mitochondrial swelling induced by cyclophilin D activation and mitochondrial permeability transition pore opening. We further investigated the mechanism underlying the role of cyclophilin D in mouse models and PC12 cell models of intracerebral hemorrhage. We found that both cyclosporin A inhibition and short hairpin RNA interference of cyclophilin D reduced mitochondrial permeability transition pore opening and mitochondrial injury. In addition, inhibition of cyclophilin D and mitochondrial permeability transition pore opening protected corticospinal tract integrity and alleviated motor dysfunction caused by intracerebral hemorrhage. Our findings suggest that cyclophilin D is used as a key mediator of axonal degeneration after intracerebral hemorrhage; inhibition of cyclophilin D expression can protect mitochondrial structure and function and further alleviate corticospinal tract injury and motor dysfunction after intracerebral hemorrhage. Our findings provide a therapeutic target for preventing axonal degeneration of white matter injury and subsequent functional impairment in central nervous diseases.
PubMed: 36204853
DOI: 10.4103/1673-5374.353495