scholarly journals Alternative Targets for Modulators of Mitochondrial Potassium Channels

Molecules ◽  
2022 ◽  
Vol 27 (1) ◽  
pp. 299
Author(s):  
Antoni Wrzosek ◽  
Shur Gałecka ◽  
Monika Żochowska ◽  
Anna Olszewska ◽  
Bogusz Kulawiak

Mitochondrial potassium channels control potassium influx into the mitochondrial matrix and thus regulate mitochondrial membrane potential, volume, respiration, and synthesis of reactive oxygen species (ROS). It has been found that pharmacological activation of mitochondrial potassium channels during ischemia/reperfusion (I/R) injury activates cytoprotective mechanisms resulting in increased cell survival. In cancer cells, the inhibition of these channels leads to increased cell death. Therefore, mitochondrial potassium channels are intriguing targets for the development of new pharmacological strategies. In most cases, however, the substances that modulate the mitochondrial potassium channels have a few alternative targets in the cell. This may result in unexpected or unwanted effects induced by these compounds. In our review, we briefly present the various classes of mitochondrial potassium (mitoK) channels and describe the chemical compounds that modulate their activity. We also describe examples of the multidirectional activity of the activators and inhibitors of mitochondrial potassium channels.

Cells ◽  
2019 ◽  
Vol 8 (6) ◽  
pp. 564 ◽  
Author(s):  
Jui-Chih Chang ◽  
Chih-Feng Lien ◽  
Wen-Sen Lee ◽  
Huai-Ren Chang ◽  
Yu-Cheng Hsu ◽  
...  

It has been documented that reactive oxygen species (ROS) contribute to oxidative stress, leading to diseases such as ischemic heart disease. Recently, increasing evidence has indicated that short-term intermittent hypoxia (IH), similar to ischemia preconditioning, could yield cardioprotection. However, the underlying mechanism for the IH-induced cardioprotective effect remains unclear. The aim of this study was to determine whether IH exposure can enhance antioxidant capacity, which contributes to cardioprotection against oxidative stress and ischemia/reperfusion (I/R) injury in cardiomyocytes. Primary rat neonatal cardiomyocytes were cultured in IH condition with an oscillating O2 concentration between 20% and 5% every 30 min. An MTT assay was conducted to examine the cell viability. Annexin V-FITC and SYTOX green fluorescent intensity and caspase 3 activity were detected to analyze the cell death. Fluorescent images for DCFDA, Fura-2, Rhod-2, and TMRM were acquired to analyze the ROS, cytosol Ca2+, mitochondrial Ca2+, and mitochondrial membrane potential, respectively. RT-PCR, immunocytofluorescence staining, and antioxidant activity assay were conducted to detect the expression of antioxidant enzymes. Our results show that IH induced slight increases of O2−· and protected cardiomyocytes against H2O2- and I/R-induced cell death. Moreover, H2O2-induced Ca2+ imbalance and mitochondrial membrane depolarization were attenuated by IH, which also reduced the I/R-induced Ca2+ overload. Furthermore, treatment with IH increased the expression of Cu/Zn SOD and Mn SOD, the total antioxidant capacity, and the activity of catalase. Blockade of the IH-increased ROS production abolished the protective effects of IH on the Ca2+ homeostasis and antioxidant defense capacity. Taken together, our findings suggest that IH protected the cardiomyocytes against H2O2- and I/R-induced oxidative stress and cell death through maintaining Ca2+ homeostasis as well as the mitochondrial membrane potential, and upregulation of antioxidant enzymes.


2020 ◽  
Vol 22 (Supplement_1) ◽  
pp. S4-S13
Author(s):  
Eva Correia-Álvarez ◽  
James E Keating ◽  
Gary Glish ◽  
Robert Tarran ◽  
M Flori Sassano

Abstract Introduction The use of flavors in electronic cigarettes appeals to adults and never-smoking youth. Consumption has rapidly increased over the last decade, and in the U.S. market alone, there are over 8000 unique flavors. The U.S. Food and Drug Administration (FDA) has begun to regulate e-liquids, but many have not been tested, and their impact, both at the cellular level, and on human health remains unclear. Methods We tested e-liquids on the human cell line HEK293T and measured toxicity, mitochondrial membrane potential (ΔΨ  m), reactive oxygen species production (ROS), and cellular membrane potential (Vm) using high-throughput screening (HTS) approaches. Our HTS efforts included single-dose and 16-point dose–response curves, which allowed testing of ≥90 commercially available e-liquids in parallel to provide a rapid assessment of cellular effects as a proof of concept for a fast, preliminary toxicity method. We also investigated the chemical composition of the flavors via gas chromatography–mass spectrometry. Results We found that e-liquids caused a decrease in ΔΨ  m and Vm and an increase in ROS production and toxicity in a dose-dependent fashion. In addition, the presence of five specific chemical components: vanillin, benzyl alcohol, acetoin, cinnamaldehyde, and methyl-cyclopentenolone, but not nicotine, were linked with the changes observed in the cellular traits studied. Conclusion Our data suggest that ΔΨ  m, ROS, Vm, and toxicity may be indicative of the extent of cell death upon e-liquid exposure. Further research on the effect of flavors should be prioritized to help policy makers such as the FDA to regulate e-liquid composition. Implications E-liquid cellular toxicity can be predicted using parameters amenable to HTS. Our data suggest that ΔΨ  m, ROS, Vm, and toxicity may be indicative of the extent of cell death upon e-liquid exposure, and this toxicity is linked to the chemical composition, that is, flavoring components. Further research on the effect of flavors should be prioritized to help policy makers such as the FDA to regulate e-liquid composition.


Author(s):  
Rohini D. ◽  
Vijayalakshmi K.

<p><strong>Objective: </strong>To investigate the neuroprotective effect of sesamol against rotenone-induced cell death in SH-SY5Y cells associated with Parkinsonism.</p><p><strong>Methods: </strong>SH-SY5Y cells were maintained in Dulbecco’s modified Eagle’s medium. After differentiation, the cells were incubated with rotenone (20 μM) and sesamol at different concentrations (10-100 μM). Cell viability was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide assay. The reactive oxygen species, mitochondrial membrane potential and nuclear morphology were determined by dichlorofluorescein diacetate, rhodamine 123 and 4’, 6-diamidino-2-phenylindole, respectively. Thiobarbituric acid reactive substances, activities of catalase, superoxide dismutase, and glutathione peroxidase and glutathione level were determined by standard assays.</p><p><strong>Results: </strong>Sesamol significantly increased the cell viability and decreased the rotenone-induced cell death in SH-SY5Y cells. Sesamol antagonized rotenone-induced reactive oxygen species generation, loss of mitochondrial membrane potential and nuclear damage. Sesamol also decreased thiobarbituric acid reactive substances level, increased the activities of catalase, superoxide dismutase, glutathione peroxidase and increased the level of glutathione in rotenone-induced cells.</p><p><strong>Conclusion: </strong>The results obtained strongly indicate the promising neuroprotective role of sesamol against rotenone-induced death in SH-SY5Y cells.</p>


2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Tiantian Xu ◽  
Qing Song ◽  
Li Zhou ◽  
Wenwen Yang ◽  
Xiangyao Wu ◽  
...  

Abstract Background Lipotoxicity-induced cell death plays a detrimental role in the pathogenesis of metabolic diseases. Ferulic acid, widespread in plant-based food, is a radical scavenger with multiple bioactivities. However, the benefits of ferulic acid against hepatic lipotoxicity are largely unclear. Here, we investigated the protective effect of ferulic acid against palmitate-induced lipotoxicity and clarified its potential mechanisms in AML-12 hepatocytes. Methods AML-12 mouse hepatocytes were exposed to palmitate to mimic lipotoxicity. Different doses (25, 50, and 100 μM) of ferulic acid were added 2 h before palmitate treatment. Cell viability was detected by measuring lactate dehydrogenase release, nuclear staining, and the expression of cleaved-caspase-3. Intracellular reactive oxygen species content and mitochondrial membrane potential were analysed by fluorescent probes. The potential mechanisms were explored by molecular biological methods, including Western blotting and quantitative real-time PCR, and were further verified by siRNA interference. Results Our data showed that ferulic acid significantly inhibited palmitate-induced cell death, rescued mitochondrial membrane potential, reduced reactive oxygen species accumulation, and decreased inflammatory factor activation, including IL-6 and IL-1beta. Ferulic acid significantly stimulated autophagy in hepatocytes, whereas autophagy suppression blocked the protective effect of ferulic acid against lipotoxicity. Ferulic acid-activated autophagy, which was triggered by SIRT1 upregulation, was mechanistically involved in its anti-lipotoxicity effects. SIRT1 silencing blocked most beneficial changes induced by ferulic acid. Conclusions We demonstrated that the phytochemical ferulic acid, which is found in plant-based food, protected against hepatic lipotoxicity, through the SIRT1/autophagy pathway. Increased intake of ferulic acid-enriched food is a potential strategy to prevent and/or improve metabolic diseases with lipotoxicity as a typical pathological feature.


Tumor Biology ◽  
2017 ◽  
Vol 39 (2) ◽  
pp. 101042831769431 ◽  
Author(s):  
Satabdi Datta ◽  
Diptiman Choudhury ◽  
Amlan Das ◽  
Dipanwita Das Mukherjee ◽  
Nabanita Das ◽  
...  

Paclitaxel (Tx) is one of the first-line chemotherapeutic drugs used against lung cancer, but acquired resistance to this drug is a major challenge against successful chemotherapy. In this work, we have focused on the chronological changes of various cellular parameters and associated effect on Tx (10 nM) resistance development in A549 cell line. It was observed, at initial stage, the cell death percentage due to drug treatment had increased up to 20 days, and thereafter, it started declining and became completely resistant by 40 days. Expressions of βIII tubulin and drug efflux pumps also increased over the period of resistance development. Changes in cellular autophagy and reactive oxygen species generation showed a biphasic pattern and increased gradually over the course of upto 20 days, thereafter declined gradually; however, their levels remained higher than untreated cells when resistance was acquired. Increase in extracellular acidification rates and oxygen consumption rates was found to be directly correlated with acquisition of resistance. The depolarisation of mitochondrial membrane potential was also biphasic; first, it increased with increase of cell death up to 20 days, thereafter, it gradually decreased to normal level along with resistance development. Increase in activity of catalase, glutathione peroxidase and glutathione content over these periods may attribute in bringing down the reactive oxygen species levels and normalisation of mitochondrial membrane potential in spite of comparatively higher reactive oxygen species production by the Tx-resistant cells.


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