Bax and caspases regulate increased production of mitochondria-derived reactive species in neuronal apoptosis: LACK of A role for depletion of cytochrome c from the mitochondrial electron transport chain

High glucose and high lipid induced mitochondrial dysfunction in JEG-3 cells through oxidative stress

Few studies focused on the roles of high glucose combined with high lipid in placental development or fetal growth. This study was designed to investigate the roles of high glucose combined with high lipid in mitochondrial dysfunction of JEG-3 cells. We determined the cellular proliferation and apoptosis, superoxide dismutase (SOD) activity, concentration of malondialdehyde (MDA), and lactic acid dehydrogenase in control group, high glucose group, high lipid group, and high glucose and high lipid group, together with the mitochondrial dysfunction, Nrf2, HO-1, SMAC, and cytochrome C (Cyt-C) expression. Significant decrease of SOD and significant elevation of MDA was seen in high glucose and high lipid group compared with the other three groups. There was significant decrease in mitochondrial SMAC and Cyt-C in high glucose group, high lipid group, and high glucose and high lipid group compared with those of control group. Nrf2 and HO-1 protein expression in high glucose combined with high lipid group showed significant decrease compared with that of high lipid group or high glucose group. We speculated that combination of high glucose and high lipid induced oxidative stress in JEG-3 cells, and Nrf2/ARE pathway may be related to this process.

Cytochrome P450-mediated antiseizure medication interactions influence apoptosis, modulate the brain BAX/Bcl-XL ratio and aggravate mitochondrial stressors in human pharmacoresistant epilepsy

Polytherapy with antiseizure medications (ASMs) is often used to control seizures in patients suffering from epilepsy, where about 30% of patients are pharmacoresistant. While drug combinations are intended to be beneficial, the consequence of CYP-dependent drug interactions on apoptotic protein levels and mitochondrial function in the epileptic brain remains unclear. We examined the interactions of ASMs given prior to surgery in surgically resected brain tissues and of three ASMs (lacosamide, LCM; oxcarbazepine, OXC; levetiracetam LEV) in isolated brain cells from patients with drug-resistant epilepsy (n = 23). We divided the patients into groups-those who took combinations of NON-CYP + CYP substrate ASMs, NON-CYP + CYP inducer ASMs, CYP substrate + CYP substrate or CYP substrate + CYP inducer ASMs-to study the 1) pro- and anti-apoptotic protein levels and other apoptotic signaling proteins and levels of reactive oxygen species (reduced glutathione and lipid peroxidation) in brain tissues; 2) cytotoxicity at blood-brain barrier epileptic endothelial cells (EPI-ECs) and subsequent changes in mitochondrial membrane potential in normal neuronal cells, following treatment with LCM + OXC (CYP substrate + CYP inducer) or LCM + LEV (CYP substrate + NON-CYP-substrate) after blood-brain barrier penetration, and 3) apoptotic and mitochondrial protein targets in the cells, pre-and post-CYP3A4 inhibition by ketoconazole and drug treatments. We found an increased BAX (pro-apoptotic)/Bcl-XL (anti-apoptotic) protein ratio in epileptic brain tissue after treatment with CYP substrate + CYP substrate or inducer compared to NON-CYP + CYP substrate or inducer, and subsequently decreased glutathione and elevated lipid peroxidation levels. Further, increased cytotoxicity and Mito-ID levels, indicative of compromised mitochondrial membrane potential, were observed after treatment of LCM + OXC in combination compared to LCM + LEV or these ASMs alone in EPI-ECs, which was attenuated by pre-treatment of CYP inhibitor, ketoconazole. A combination of two CYP-mediated ASMs on EPI-ECs resulted in elevated caspase-3 and cytochrome c with decreased SIRT3 levels and activity, which was rescued by CYP inhibition. Together, the study highlights for the first time that pro- and anti-apoptotic proteins levels are dependent on ASM combinations in epilepsy, modulated via a CYP-mediated mechanism that controls free radicals, cytotoxicity and mitochondrial activity. These findings lead to a better understanding of future drug selection choices offsetting pharmacodynamic CYP-mediated interactions.

Atractylodin Induces Apoptosis and Inhibits the Migration of A549 Lung Cancer Cells by Regulating ROS-Mediated Signaling Pathways

Atractylodin (ATR) has anticancer effects on some tumor cells by inducing apoptosis, but its mechanism in lung cancer remains unclear. This study investigates the inhibitory effect of ATR on A549 lung cancer cells. Cell viability was detected by the Cell Counting Kit-8 assay, and results showed that ATR could significantly inhibit the proliferation of A549 cells. Apoptosis was detected by Annexin V-FITC/PI staining, and apoptosis rate and mitochondrial membrane potential were detected by flow cytometry. Results showed that the effect of ATR on the apoptosis of A549 cells was negatively correlated with the change in mitochondrial membrane potential. Western blot analysis showed that ATR regulated apoptosis induced by mitogen-activated protein kinase, signal transducer and activator of transcription 3, and nuclear factor kappa B signaling pathways. Analyses of reactive oxygen species (ROS), cell cycle, and cell migration showed that ATR induced intracellular ROS accumulation as an initiation signal to induce cell cycle arrest regulated by the AKT signaling pathway and cell migration inhibition regulated by the Wnt signaling pathway. Results showed that ATR can inhibit cell proliferation, induce cell apoptosis, induce cell cycle arrest, and inhibit the migration of A549 cells (p < 0.05 was considered statistically significant, * p < 0.05, ** p < 0.01 and *** p < 0.001).

Bax Contributes to Retinal Ganglion Cell Dendritic Degeneration During Glaucoma

The BCL-2 (B-cell lymphoma-2) family of proteins contributes to mitochondrial-based apoptosis in models of neurodegeneration, including glaucomatous optic neuropathy (glaucoma), which degrades the retinal ganglion cell (RGC) axonal projection to the visual brain. Glaucoma is commonly associated with increased sensitivity to intraocular pressure (IOP) and involves a proximal program that leads to RGC dendritic pruning and a distal program that underlies axonopathy in the optic projection. While genetic deletion of the Bcl2-associated X protein (Bax^-/-) prolongs RGC body survival in models of glaucoma and optic nerve trauma, axonopathy persists, thus raising the question of whether dendrites and the RGC light response are protected. Here, we used an inducible model of glaucoma in Bax^-/- mice to determine if Bax contributes to RGC dendritic degeneration. We performed whole-cell recordings and dye filling in RGCs signaling light onset (αON-Sustained) and offset (αOFF-Sustained). We recovered RGC dendritic morphologies by confocal microscopy and analyzed dendritic arbor complexity and size. Additionally, we assessed RGC axon function by measuring anterograde axon transport of cholera toxin subunit B to the superior colliculus and behavioral spatial frequency threshold (i.e., spatial acuity). We found 1 month of IOP elevation did not cause significant RGC death in either WT or Bax^-/- retinas. However, IOP elevation reduced dendritic arbor complexity of WT αON-Sustained and αOFF-Sustained RGCs. In the absence of Bax, αON- and αOFF-Sustained RGC dendritic arbors remained intact following IOP elevation. In addition to dendrites, neuroprotection by Bax^-/- generalized to αON-and αOFF-Sustained RGC light- and current-evoked responses. Both anterograde axon transport and spatial acuity declined during IOP elevation in WT and Bax^-/- mice. Collectively, our results indicate Bax contributes to RGC dendritic degeneration and distinguishes the proximal and distal neurodegenerative programs involved during the progression of glaucoma.

iTRAQ-based mitochondrial proteome analysis of the molecular mechanisms underlying postharvest senescence of Zizania latifolia

To explore the molecular mechanisms underlying postharvest senescence of Zizania latifolia, the changes in the mitochondrial proteome of plants treated with or without (control) 1-methyleyelopropene and ethylene during storage at room temperature for 0, 3 and 6 days were investigated using isobaric tags for relative and absolute quantitation (iTRAQ) labeling combined with two-dimensional liquid chromatography-tandem mass spectrometry. A total of 1,390 proteins with two or more peptides were identified, of which 211 showed a significant (p < .05) change (at least twofold) in relative abundance. Monitoring the parallel reaction validated the reliability and accuracy of the iTRAQ results. Bioinformatics and functional analysis of these differentially expressed proteins (DEPs) revealed that postharvest senescence of Z. latifolia could be attributed to (a) strengthened pentose phosphate pathway, (b) imbalanced protein, amino acid, organic acid, and fatty acid metabolism, (c) disordered energy homeostasis, (d) exacerbated oxidative damage, (e) RNA degradation, (f) activation of the Ca²⁺ , mitogen-activated protein kinase, and jasmonic acid signaling pathways, (g) programed cell death, (h) excessive biosynthesis of secondary metabolites, or (i) degradation of cell structure. Our findings provide integrated insight into the molecular mechanisms of postharvest senescence during storage as well as the DEPs that show promise as targets for controlling senescence-induced quality deterioration of Z. latifolia. PRACTICAL APPLICATIONS: Postharvest senescence is the most important factor that causes fast quality deterioration of Zizania latifolia. The understanding of the processes leading to postharvest senescence of Z. latifolia is essential in enhancing the commercial value and extending the shelf life of the product. It is currently believed that the mitochondrial metabolism is closely related to postharvest senescence. For this, the changes of proteome in Z. latifolia mitochondria treated with or without (control) 1-MCP and ETH during storage at room temperature were investigated. Results showed that a variety of physiobiochemical responses occur during postharvest senescence of Z. latifolia. 1-MCP treatment significantly inhibited the changes of these physiobiochemical processes, finally, retarding the postharvest senescence of Z. latifolia. ETH treatment had opposite effects on proteome changes compared with 1-MCP treatment. Taken together, these results enrich the understanding of the molecular mechanisms of postharvest senescence of Z. latifolia.

The Apoptotic and Anti-apoptotic Effects of Pendimethalin and Trifluralin on A549 Cells In Vitro

Objectives

Pendimethalin and trifluralin are commonly used in many countries to control broadleaf weeds and grassy weed species because of their inhibitor effects on growth and cell division. In this study, we examined the apoptotic and anti-apoptotic potentials of pendimethalin and trifluralin on A549 human non-small lung cancer cells with several concentrations in vitro.

Materials and Methods

The expression levels of apoptosis-related genes BCL-2, BAX, CAS3, CAS9, P53, BIRC, and PPIA were examined using quantitative RT-PCR after 24 h treatment of 1, 10, 50, 100 and 500 μM pendimethalin and trifluralin.

Results

The effects of pendimethalin were found more repressive than trifluralin on all studied concentrations. Twenty-four hours' exposure with 100 μM pendimethalin and trifluralin altered the gene expressions, suppressing apoptosis and allowing cancer cells to grow and proliferate.

Conclusion

Care should be taken not to exceed the permissible values and residue limits in food during pendimethalin and trifluralin use in order to reduce the possible carcinogenic effects on humans.

Cytotoxicity of Air Pollutant 9,10-Phenanthrenequinone: Role of Reactive Oxygen Species and Redox Signaling

Atmospheric pollution has been a principal topic recently in the scientific and political community due to its role and impact on human and ecological health. 9,10-phenanthrenequinone (9,10-PQ) is a quinone molecule found in air pollution abundantly in the diesel exhaust particles (DEP). This compound has studied extensively and has been shown to develop cytotoxic effects both in vitro and in vivo. 9, 10-PQ has been proposed to play a critical role in the development of cytotoxicity via generation of reactive oxygen species (ROS) through redox cycling. This compound also reduces expression of glutathione (GSH), which is critical in Phase II detoxification reactions. Understanding the underlying cellular mechanisms involved in cytotoxicity can allow for the development of therapeutics designed to target specific molecules significantly involved in the 9,10-PQ-induced ROS toxicity. This review highlights the developments in the understanding of the cytotoxic effects of 9, 10-PQ with special emphasis on the possible mechanisms involved.