Isofraxidin, a potent reactive oxygen species (ROS) scavenger, protects human leukemia cells from radiation-induced apoptosis via ROS/mitochondria pathway in p53-independent manner

Effects of nitrogen on the apoptosis of and changes in gene expression in human lymphoma U937 cells exposed to argon-based cold atmospheric pressure plasma

Cold atmospheric pressure plasma (CAP) is known as a source of biologically active agents, such as reactive oxygen species (ROS) and reactive nitrogen species (RNS). In the present study, we examined the effects of nitrogen (N2) on the apoptosis of and changes in gene expression in human lymphoma U937 cells exposed to argon (Ar)-CAP. Enormous amounts of hydroxyl (·OH) radicals in aqueous solution were produced using Ar‑CAP generated using a 20 kHz low frequency at 18 kV with a flow rate of 2 l/min. The increase in the levels of ·OH radicals was significantly attenuated by the addition of N2 to Ar gas. On the other hand, the level of total nitrate/nitrite in the supernatant was significantly elevated in the Ar + N2-CAP‑exposed U937 cells. When the cells were exposed to Ar‑CAP, a significant increase in apoptosis was observed, whereas apoptosis was markedly decreased in the cells exposed to Ar + N2-CAP. Microarray and pathway analyses revealed that a newly identified gene network containing a number of heat shock proteins (HSPs), anti-apoptotic genes, was mainly associated with the biological function of the prevention of apoptosis. Quantitative PCR revealed that the expression levels of HSPs were significantly elevated in the cells exposed to Ar + N2-CAP than those exposed to Ar‑CAP. These results indicate that N2 gas in Ar‑CAP modifies the ratio of ROS to RNS, and suppresses the apoptosis induced by Ar‑CAP. The modulation of gaseous conditions in CAP may thus prove to be useful for future clinical applications, such as for switching from a sterilizing mode to cytocidal effect for cancer cells.

Near-infrared photothermal therapy of Prussian-blue-functionalized lanthanide-ion-doped inorganic/plasmonic multifunctional nanostructures for the selective targeting of HER2-expressing breast cancer cells

Multifunctional nanostructure for photothermal therapy of cancer cells.

Dynamic comparisons of high-resolution expression profiles highlighting mitochondria-related genes between in vivo and in vitro fertilized early mouse embryos

STUDY QUESTION

Does in vitro fertilization (IVF) induce comprehensive and consistent changes in gene expression associated with mitochondrial biogenesis and function in mouse embryos from the pre- to post-implantation stage?

SUMMARY ANSWER

IVF-induced consistent mitochondrial dysfunction in early mouse embryos by altering the expression of a number of mitochondria-related genes.

WHAT IS KNOWN ALREADY

Although IVF is generally safe and successful for the treatment of human infertility, there is increasing evidence that those conceived by IVF suffer increased health risks. The mitochondrion is a multifunctional organelle that plays a crucial role in early development. We hypothesized that mitochondrial dysfunction is associated with increased IVF-induced embryonic defects and risks in offspring.

STUDY DESIGN, SIZE, DURATION

After either IVF and development (IVO groups as control) or IVF and culture (IVF groups), blastocysts were collected and transferred to pseudo-pregnant recipient mice. Both IVO and IVF embryos were sampled at E3.5, E7.5 and E10.5, and the expression profiles of mitochondria-related genes from the pre- to post-implantation stage were compared.

PARTICIPANTS/MATERIALS, SETTING, METHODS

ICR mice (5- to 6-week-old males and 8- to 9-week-old females) were used to generate IVO and IVF blastocysts. Embryo day (E) 3.5 blastocysts were transferred to pseudo-pregnant recipient mice. Both IVO and IVF embryos were sampled at E3.5, E7.5 and E10.5 for generating transcriptome data. Mitochondria-related genes were filtered for dynamic functional profiling. Mitochondrial dysfunctions indicated by bioinformatic analysis were further validated using cytological and molecular detection, morphometric and phenotypic analysis and integrated analysis with other high-throughput data.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 806, 795 and 753 mitochondria-related genes were significantly (P < 0.05) dysregulated in IVF embryos at E3.5, E7.5 and E10.5, respectively. Dynamic functional profiling, together with cytological and molecular investigations, indicated that IVF-induced mitochondrial dysfunctions mainly included: (i) inhibited mitochondrial biogenesis and impaired maintenance of DNA methylation of mitochondria-related genes during the post-implantation stage; (ii) dysregulated glutathione/glutathione peroxidase (GSH/Gpx) system and increased mitochondria-mediated apoptosis; (iii) disturbed mitochondrial β-oxidation, oxidative phosphorylation and amino acid metabolism; and (iv) disrupted mitochondrial transmembrane transport and membrane organization. We also demonstrated that some mitochondrial dysfunctions in IVF embryos, including impaired mitochondrial biogenesis, dysregulated GSH homeostasis and reactive oxygen species-induced apoptosis, can be rescued by treatment with melatonin, a mitochondria-targeted antioxidant, during in vitro culture.

LIMITATIONS, REASONS FOR CAUTION

Findings in mouse embryos and fetuses may not be fully transferable to humans. Further studies are needed to confirm these findings and to determine their clinical significance better.

WIDER IMPLICATIONS OF THE FINDINGS

The present study provides a new insight in understanding the mechanism of IVF-induced aberrations during embryonic development and the increased health risks in the offspring. In addition, we highlighted the possibility of improving existing IVF systems by modulating mitochondrial functions.

EPR-Spin Trapping and Flow Cytometric Studies of Free Radicals Generated Using Cold Atmospheric Argon Plasma and X-Ray Irradiation in Aqueous Solutions and Intracellular Milieu

Electron paramagnetic resonance (EPR)-spin trapping and flow cytometry were used to identify free radicals generated using argon-cold atmospheric plasma (Ar-CAP) in aqueous solutions and intracellularly in comparison with those generated by X-irradiation. Ar-CAP was generated using a high-voltage power supply unit with low-frequency excitation. The characteristics of Ar-CAP were estimated by vacuum UV absorption and emission spectra measurements. Hydroxyl (·OH) radicals and hydrogen (H) atoms in aqueous solutions were identified with the spin traps 5,5-dimethyl-1-pyrroline N-oxide (DMPO), 3,3,5,5-tetramethyl-1-pyrroline-N-oxide (M₄PO), and phenyl N-t-butylnitrone (PBN). The occurrence of Ar-CAP-induced pyrolysis was evaluated using the spin trap 3,5-dibromo-4-nitrosobenzene sulfonate (DBNBS) in aqueous solutions of DNA constituents, sodium acetate, and L-alanine. Human lymphoma U937 cells were used to study intracellular oxidative stress using five fluorescent probes with different affinities to a number of reactive species. The analysis and quantification of EPR spectra revealed the formation of enormous amounts of ·OH radicals using Ar-CAP compared with that by X-irradiation. Very small amounts of H atoms were detected whereas nitric oxide was not found. The formation of ·OH radicals depended on the type of rare gas used and the yield correlated inversely with ionization energy in the order of krypton > argon = neon > helium. No pyrolysis radicals were detected in aqueous solutions exposed to Ar-CAP. Intracellularly, ·OH, H₂O₂, which is the recombination product of ·OH, and OCl^- were the most likely formed reactive oxygen species after exposure to Ar-CAP. Intracellularly, there was no practical evidence for the formation of NO whereas very small amounts of superoxides were formed. Despite the superiority of Ar-CAP in forming ·OH radicals, the exposure to X-rays proved more lethal. The mechanism of free radical formation in aqueous solutions and an intracellular milieu is discussed.

Complexity of Compensatory Effects in Nrf1 Knockdown: Linking Undeveloped Anxiety-Like Behavior to Prevented Mitochondrial Dysfunction and Oxidative Stress

Anxiety-related disorders are complex illnesses that underlying molecular mechanisms need to be understood. Mitochondria stand as an important link between energy metabolism, oxidative stress, and anxiety. The nuclear factor, erythroid-derived 2,-like 1(Nrf1) is a member of the cap "n" collar subfamily of basic region leucine zipper transcription factors and plays the major role in regulating the adaptive response to oxidants and electrophiles within the cell. Here, we injected small interfering RNA (siRNA) targeting Nrf1 in dorsal third ventricle of adult male albino Wistar rats and subsequently examined the effect of this silencing on anxiety-related behavior. We also evaluated apoptotic markers and mitochondrial biogenesis factors, along with electron transport chain activity in three brain regions: hippocampus, amygdala, and prefrontal cortex. Our data revealed that in the group that received Nrf1-siRNA, anxiety-related behavior did not show any significant changes compared to the control group. Caspase-3 did not increase in Nrf1-siRNA-injected rats even though Bax/Bcl2 ratio markedly elevated in Nrf1-knockdown rats in all three mentioned regions compared to control rats. Also, Nrf1 silencing of complex I and II-III did not alter, generally. In addition, Nrf1-knockdown affected mitochondrial biogenesis markers. The level of peroxisome proliferator-activated receptor gamma coactivator-1α and cytochrome-c increased, which indicates a possible role for mitochondrial biogenesis in anxiety.

Tyrosol prevents ischemia/reperfusion-induced cardiac injury in H9c2 cells: involvement of ROS, Hsp70, JNK and ERK, and apoptosis

Ischemia-Reperfusion (I/R) injury causes ROS overproduction, creating oxidative stress, and can trigger myocyte death, resulting in heart failure. Tyrosol is an antioxidant abounded in diets and medicine. Our objective was to investigate the protective effect of tyrosol on I/R-caused mortality in H9c2 cardiomyocytes through its influence on ROS, Hsp70, ERK, JNK, Bcl-2, Bax and caspase-8. A simulated I/R model was used, myocytes loss was examined by MTT, and ROS levels were measured using DCFH-DA. Nuclear condensation and caspase-3 activity were assessed by DAPI staining and fluorometric assay. Phosphorylated ERK and JNK were determined by electrochemiluminescent ELISA, and Hsp70, Bcl-2, Bax and caspase-8 were examined by Western blotting. Results show that tyrosol salvaged myocyte loss, inhibited nuclear condensation and caspase-3 activity dose-dependently, indicating its protection against I/R-caused myocyte loss. Furthermore, tyrosol significantly inhibited ROS accumulation and activation of ERK and JNK, augmenting Hsp70 expression. Besides, tyrosol inhibited I/R-induced apoptosis, associated with retained anti-apoptotic Bcl-2 protein, and attenuated pro-apoptotic Bax protein, resulting in a preservation of Bcl-2/Bax ratio. Finally, tyrosol notably decreased cleaved caspase-8 levels. In conclusion, cytoprotection of tyrosol in I/R-caused myocyte mortality was involved with the mitigation of ROS, prohibition of the activation of ERK, JNK and caspase-8, and elevation of Hsp70 and Bcl-2/Bax ratio.

Synthesis and antitumor mechanisms of a copper(ii) complex of anthracene-9-imidazoline hydrazone (9-AIH)

A copper(ii) complex of anthracene-9-imidazoline hydrazone induced cell apoptosis by suppressing mutant p53 expression and activating caspase cascade pathway.

A study on effects of naphthalimide derivative-capped quantum dots on the cellular internalization, proliferation, and apoptosis ability

Quantum dots (QDs) have shown great potential in monitoring and imaging cancer cells because of their unique photochemical and photophysical properties. However, it is little-known whether QDs affect the cellular internalization, proliferation and apoptosis. Here a new class of multifunctional QDs capped with ligands that possess l-Lys or l-Arg and naphthalimide (NI), linked by carboxyl groups (l-Lys-NI@QDs and l-Arg-NI@QDs, respectively), have been synthesized. We found that these QDs are of controllable sizes, in the range of 4 to 5 nm and have strong optical emission properties. The cellular uptake of NI derivative-capped QDs was monitored by flow cytometry and confocal microscopy. The results of in vitro cytotoxicity revealed that NI derivative-capped QDs, with better cell selectivity, could inhibit the growth of multiple cancer cells more potently than amonafide. They effectively inhibited the proliferation of cells due to apoptosis, which was confirmed by Hoechst 33342, annexin V-FITC and JC-1 staining and mitochondrial membrane potential (MMP) experiments. The most potent NI derivative-capped QDs, l-Arg-NI@CdSe/ZnS, were verified to efficiently induce apoptosis via a reactive oxygen species (ROS) mediating mitochondrial dysfunction, and were more effective in promoting programmed cell death in HepG2 cells in a preliminary mechanistic study.

Hydroxysafflor yellow A induces apoptosis in MCF-7 cells by blocking NFκB/p65 pathway and disrupting mitochondrial transmembrane potential

The molecular mechanisms and the possible effects of hydroxysafflor yellow A (HSYA) on the induction of apoptosis in the human breast cancer MCF-7 cells were investigated.