scholarly journals EXTH-58. ONCOSCILLATORS: INDUCTION OF THE MITOCHONDRIAL PERMEABILITY TRANSITION IN CANCER CELLS

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii99-ii100
Author(s):  
Martyn Sharpe ◽  
David Baskin ◽  
Santosh Helekar
Keyword(s):  
Magnetic Field ◽  
Hydrogen Peroxide ◽  
Magnetic Fields ◽  
Cancer Cells ◽  
Membrane Permeability ◽  
Mitochondrial Permeability Transition ◽  
Permeability Transition ◽  
Radical Pairs ◽  
Membrane Permeability Transition ◽  
Mitochondrial Permeability

Abstract Magnetic fields in the mT range influence spin state pairing in redox-active radical pairs generating spin-forbidden quantum states which are kinetically inert. Studies examining the effects of static magnetic fields on mitochondrial electron transfer kinetics have demonstrated only modest effects. When neodymium super-magnets are securely attached to and precision-balanced on the shafts of electronically-controlled motors it is possible to generate rotating magnetic fields of desirable strengths and frequencies. Unlike a static magnetic field or an alternating field in a static electromagnetic coil, oscillating magnetic field (OMF) produced by rotating lines of force of a spinning permanent magnet can dynamically couple the electron spins of radical pairs within proteins whose orientations are ‘fixed’. The frequencies of rotation of magnets can also be tuned to appropriate electron cycling resonances within the proteins. Using OMF of appropriate field strength, frequency and on/off acceleration/deceleration profiles we can completely arrest electron transport in isolated respiring rat liver mitochondria. Parallel to this inhibition of electron flux, we also independently observe an increase in superoxide and hydrogen peroxide. Under certain OMF exposure regimes, we observe membrane permeability transition in these mitochondria when using succinate as substrate, and show that the mitochondrial membrane permeability transition effect can be blocked by bongkrekic acid. We have examined the effect of OMF on oxygen consumption in cultured primary cancer cells with a rotating magnet (oncoscillator) that is an integral component of a new anti-cancer Oncomagnetic device. We observe three main effects in addition to the inhibition of respiratory flux in cancer cells – damage to the respiratory complex, uncoupling and generation of superoxide/hydrogen peroxide. OMF generated by oncoscillators can induce mitochondrial permeability transition in primary cultured malignant meningioma, diffuse intrinsic pontine glioma and GBM cells. Parallel experiments with normal human astrocytes show only minor changes in cellular/mitochondrial function under these conditions.

scholarly journals On the Mechanism(s) of Membrane Permeability Transition in Liver Mitochondria of Lamprey,Lampetra fluviatilis L.: Insights from Cadmium

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Elena A. Belyaeva ◽  
Larisa V. Emelyanova ◽  
Sergey M. Korotkov ◽  
Irina V. Brailovskaya ◽  
Margarita V. Savina
Keyword(s):  
Membrane Permeability ◽  
Cyclosporine A ◽  
Mitochondrial Permeability Transition Pore ◽  
Mitochondrial Permeability Transition ◽  
Permeability Transition Pore ◽  
Permeability Transition ◽  
Liver Mitochondria ◽  
Nitrate Medium ◽  
Lampetra Fluviatilis ◽  
Mitochondrial Permeability

Previously we have shown that opening of the mitochondrial permeability transition pore in its low conductance state is the case in hepatocytes of the Baltic lamprey (Lampetra fluviatilis L.) during reversible metabolic depression taking place in the period of its prespawning migration when the exogenous feeding is switched off. The depression is observed in the last year of the lamprey life cycle and is conditioned by reversible mitochondrial dysfunction (mitochondrial uncoupling in winter and coupling in spring). To further elucidate the mechanism(s) of induction of the mitochondrial permeability transition pore in the lamprey liver, we used Cd2+and Ca2+plus Pias the pore inducers. We found that Ca2+plus Piinduced the high-amplitude swelling of the isolated “winter” mitochondria both in isotonic sucrose and ammonium nitrate medium while both low and high Cd2+did not produce the mitochondrial swelling in these media. Low Cd2+enhanced the inhibition of basal respiration rate of the “winter” mitochondria energized by NAD-dependent substrates whereas the same concentrations of the heavy metal evoked its partial stimulation on FAD-dependent substrates. The above changes produced by Cd2+or Ca2+plus Piin the “winter” mitochondria were only weakly (if so) sensitive to cyclosporine A (a potent pharmacological desensitizer of the nonselective pore) added alone and they were not sensitive to dithiothreitol (a dithiol reducing agent). Under monitoring of the transmembrane potential of the “spring” lamprey liver mitochondria, we revealed that Cd2+produced its decrease on both types of the respiratory substrates used that was strongly hampered by cyclosporine A, and the membrane potential was partially restored by dithiothreitol. The effects of different membrane permeability modulators on the lamprey liver mitochondria function and the seasonal changes in their action are discussed.

scholarly journals Mitochondrial ROS Release and Subsequent Akt Activation Potentially Mediated the Anti-Apoptotic Effect of a 50-Hz Magnetic Field on FL Cells

2016 ◽  
Vol 38 (6) ◽  
pp. 2489-2499 ◽  
Author(s):  
Baihuan Feng ◽  
Chunmei Ye ◽  
Liping Qiu ◽  
Liangjing Chen ◽  
Yiti Fu ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Mitochondrial Permeability Transition ◽  
Permeability Transition ◽  
Akt Activation ◽  
Mitochondrial Permeability ◽  
Mitochondrial Ros ◽  
Phosphorylated Akt ◽  
Early Apoptosis ◽  
Apoptotic Effect ◽  
Permeability Transition Pores

Background/Aims: Our previous study showed that exposure to a 50-Hz magnetic field (MF) could induce transient mitochondrial permeability transition (MPT) in cells. In the present study, the aim was to explore the possible biological implications of MF-induced transient MPT. Materials and Methods: Human amniotic (FL) cells were exposed to MF for different durations or intensities followed by incubation with staurosporine for 4 h. After MF exposure, cell early apoptosis, cell viability mitochondrial ROS and the level of phosphorylated Akt were assessed. After MF exposure followed by incubation with staurosporine, cell early apoptosis was assessed. Results: MF exposure had a protective effect against early apoptosis induced by staurosporine, which could be abolished by MPT inhibitors, although MF exposure alone had no significant effect on early apoptosis or viability of cells. In addition, exposing cells to MF increased the level of mitochondrial ROS which were released into cytoplasm through mitochondrial permeability transition pores (mPTP), and induced ROS-dependent phosphorylation of Akt. Furthermore, the anti-apoptotic effect of MF exposure was completely eliminated when Akt was inhibited. Conclusions: The present study indicated a possibility that mitochondrial ROS release through mPTP and subsequent Akt activation were necessary for the anti-apoptotic effect of MF.

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