bims-aporos Biomed news
on Apoptosis and reactive oxygen species
Issue of 2018‒08‒05
eleven papers selected by
Gavin McStay
Staffordshire University

  1. Free Radic Biol Med. 2018 Jul 26. pii: S0891-5849(18)30986-9. [Epub ahead of print]
    Afrin S, Giampieri F, Forbes-Hernández TY, Gasparrini M, Amici A, Cianciosi D, Quiles JL, Battino M.
      The development of chemo-sensitizers is urgently needed to overcome 5-fluorouracil (5-FU) therapeutic resistance and adverse toxicity in colorectal cancer. This work aims to evaluate the synergic effects of 5-FU and Manuka honey (MH), a rich source of bioactive compounds, in enhancing the anticancer effects of this drug on human colon cancer HCT-116 and LoVo cells. Compared to 5-FU alone, MH synergistically enhanced the chemotherapeutic effects of 5-FU, by reducing cell proliferation through the suppression of EGFR, HER2, p-Akt and p-mTOR expression, and promoting apoptosis by the modulation pro-apoptotic (p53, Bax, Cyto c, FasL caspase-3, -8, -9 and cleave-PARP) and anti-apoptotic (Bcl-2) markers. The activations of p-p38MAPK and p-Erk1/2 pathways and ROS production were also involved in this process. Downregulation of transcription factor (NF-κB and Nrf2) and antioxidant enzyme activity (SOD, catalase, glutathione peroxidase and glutathione reductase) and expression (SOD, catalase and HO-1) were more evident after the combined treatment, leading to more cell death by oxidative stress. Moreover, additive effects were also observed by increasing lipid and protein oxidation and arresting cell cycle. All the parameters of mitochondrial respiration and glycolysis function decreased and both cells entered the quiescent stage after the combined treatments. MH also influenced the anti-metastasis effects of 5-FU by decreasing migration ability, suppressing the expression of MMP-2, MMP-9 and increasing N-cadherin and E-cadherin. In conclusion, MH could be a useful preventive or adjuvant agent in the treatment of colorectal cancer with 5-FU.
    Keywords:  5-Fluorouracil; Apoptosis; Colon cancer; Manuka honey; Reactive oxygen species; Synergistic effect
  2. Neurochem Int. 2018 Jul 25. pii: S0197-0186(18)30127-X. [Epub ahead of print]
    Kumar M, Ray RS, Sandhir R.
      Elevated homocysteine (Hcy) levels have been implicated in neurodevelopmental and neurodegenerative disorders. Induction of oxidative stress and apoptosis has been reported as major mechanism in Hcy-induced neurotoxicity. Hydrogen sulfide (H2S), as an antioxidant molecule has been reported to exhibit novel protective effect against Hcy-induced cell damage. However, the mechanisms involved in protective effect of H2S against Hcy-induced toxicity in neurons have not been fully elucidated. Herein, effect of sodium hydrogen sulfide (NaHS, a source of H2S) on Hcy-induced neurotoxicity was studied in Neuro-2a (N2a) cells in vitro and in animals subjected to hyperhomocysteinemia. DCFH-DA staining revealed that NaHS effectively attenuated Hcy-induced oxidative damage via reducing intracellular reactive oxygen species (ROS) generation. JC-1 staining and western blot results showed that NaHS pre-treatment prevented Hcy-induced mitochondrial dysfunctions and mitochondria-mediated apoptosis. The MTT assay, cell cycle analysis, ethidium bromide/acridine orange (EB/AO) and Hoechst staining results demonstrated that NaHS significantly alleviated Hcy-induced cytotoxicity in N2a cells by preventing oxidative damage. Importantly, the results from agarose gel electrophoresis, comet and TUNEL assay indicated that NaHS prevented neurodegeneration by preventing DNA damage and apoptotic cell death in animals with hyperhomocysteinemia. Taken together, the results demonstrate the protective potential of H2S against Hcy-induced neurotoxicity by preventing oxidative DNA damage and mitochondrial dysfunctions. The findings validate that H2S is a promising therapeutic molecule in neurodegenerative conditions associated with hyperhomocysteinemia.
    Keywords:  Apoptosis; Homocysteine; Hydrogen sulfide; Mitochondria; Neuroprotection; Oxidative damage
  3. Biochim Biophys Acta. 2018 Jul 26. pii: S1874-9399(18)30177-9. [Epub ahead of print]
    Li Z, Chen B, Dong W, Xu W, Song M, Fang M, Guo J, Xu Y.
      Excessive reactive oxygen species (ROS) causes irreparable damages to cells and commit cells to programmed cell death or apoptosis. A panel of well-documented pro-apoptotic genes, including p53 apoptosis effector related to PMP-22 (PERP), is up-regulated and collectively mediate ROS induced apoptosis. The epigenetic mechanism whereby ROS stimulates PERP transcription, however, lacks in-depth characterization. Here we report that the transcriptional modulator megakaryocytic leukemia 1 (MKL1) is activated by H2O2 treatment in skeletal muscle cells (C2C12). Small interfering RNA (siRNA) mediated silencing or small-molecule compound (CCG-1423) mediated inhibition of MKL1 attenuated H2O2 induced apoptosis of C2C12 cells. Over-expression of MKL1 potentiated trans-activation of PERP whereas MKL1 ablation/inhibition abrogated the induction of PERP by H2O2 in C2C12 cells. Mechanistically, MKL1 interacted with and was recruited to the PERP promoter by the transcription factor E2F1. Once bound to the PERP promoter, MKL1 engaged the histone demethylase KDM3A to modulate the chromatin structure surrounding the PERP promoter thereby leading to PERP trans-activation. Depletion of either E2F1 or KDM3A blocked the induction of PERP by H2O2. In conclusion, our data illustrate a novel epigenetic pathway that links PERP transcription to ROS-induced apoptosis in skeletal muscle cells.
    Keywords:  Apoptosis; Epigenetics; ROS; Transcriptional regulation
  4. Free Radic Biol Med. 2018 Jul 26. pii: S0891-5849(18)30939-0. [Epub ahead of print]
    Zhao G, Wu X, Chen P, Zhang L, Yang CS, Zhang J.
      We have previously demonstrated that selenium nanoparticles (SeNPs) administered via oral route possess similar capacities of increasing selenoenzyme activities as the extensively examined sodium selenite, selenomethionine and methylselenocysteine, and yet display the lowest toxicity among these selenium compounds in mouse models. However, the low toxicity of SeNPs found in mammalian systems would lead to the interpretation that the punctate distribution of elemental selenium found in cultured cancer cells subjected to selenite treatment that triggers marked cytotoxicity represents a detoxifying mechanism. The present study found that SeNPs could be reduced by the thioredoxin- or glutaredoxin-coupled glutathione system to generate ROS. Importantly, ROS production by SeNPs in these systems was more efficient than by selenite, which has been recognized as the most redox-active selenium compound for ROS production. This is because multiple steps of reduction from selenite to selenide anion are required; whereas only a single step reduction from the elemental selenium atom to selenide anion is needed to trigger redox cycling with oxygen to produce ROS. We thus speculated that accumulation of SeNPs in cancer cells would result in a strong therapeutic effect, rather than serves a detoxification function. Indeed, we showed herein that preformed SeNPs generated a potent therapeutic effect in a mouse model due to rapid, massive and selective accumulation of SeNPs in cancer cells. Overall, for the first time, we demonstrate that SeNPs have a stronger pro-oxidant property than selenite and hyper-accumulation of SeNPs in cancer cells can generate potent therapeutic effects.
    Keywords:  cancer therapy; glutathione system; reactive oxygen species; selenium nanoparticles; thioredoxin system
  5. Chem Biol Interact. 2018 Jul 25. pii: S0009-2797(18)30814-7. [Epub ahead of print]293 61-69
    Zhang X, Wang M, Teng S, Wang D, Li X, Wang X, Liao W, Wang D.
      A facile method of assembling oxindole and phthalide units through a Lewis based catalyzed allylic alkylation reaction of Morita-Baylis-Hillman carbonates of isatins and 3-cyanophthalides was recently developed. The method efficiently delivers a hybrid of 3,3'-disubstituted oxindole with a valuable phthalide pharmacophore. In the present study, we proved the deleterious effects of 5h2c, a screened synthesis compound, against hepatocellular carcinoma (HCC) in both in vitro and in vivo models. 5h2c strongly decreased cell viability, caused over-release of lactate dehydrogenase, inhibited cell migration, and enhanced the apoptosis rate in HepG2 and PLC/PRF/5 cells. 5h2c led to an increase in intracellular reactive oxygen species levels and a decrease in mitochondrial membrane potential. In HepG2-and PLC/PRF/5-xenograft tumor mouse models, treatment with 5h2c inhibited tumor growth without affecting the animals' bodyweight or organ functions. Proteome profiling of tumor tissues after 24-h exposure to 5h2c showed significantly enhanced expression levels of Bcl-2 associated X protein, cleaved caspase -3, -8, and -9, nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), heme oxygenase-2, paraoxonase 2, catalase, and factor associated suicide ligand, and reduced the expression levels of B-cell lymphoma-2, B-cell lymphoma-extra large, heat shock protein 27, heat shock protein 60, and heat shock protein 70 in HepG2 and PLC/PRF/5 cells. All of our data confirmed that oxidative stress-mediated mitochondrial apoptosis (especially the Nrf-2/HO-1 pathway) is responsible for 5h2c-induced HCC damage.
    Keywords:  Apoptosis; Hepatocellular carcinoma; Indolyl-chalcone derivatives; Mitochondria; Oxidative stress
  6. Redox Biol. 2018 Jul 20. pii: S2213-2317(18)30581-0. [Epub ahead of print]18 229-243
    Li R, Xin T, Li D, Wang C, Zhu H, Zhou H.
      Increased mitochondrial damage is related to the progression of a diet-induced nonalcoholic fatty liver disease. The aim of our study is to investigate the role of Sirtuin 3 (Sirt3) in treating nonalcoholic fatty liver disease with a focus on mitophagy and the ERK-CREB pathway. Our data indicated that Sirt3 was downregulated in liver tissue in response to chronic HFD treatment. Interestingly, re-introduction of Sirt3 protected hepatic function, attenuated liver fibrosis, alleviated the inflammatory response, and prevented hepatocyte apoptosis. Molecular investigations demonstrated that lipotoxicity was associated with an increase in mitochondrial apoptosis as evidenced by reduced mitochondrial potential, augmented ROS production, increased cyt-c leakage into the nucleus, and activated caspase-9 apoptotic signalling. Additionally, Sirt3 overexpression protected hepatocytes against mitochondrial apoptosis via promoting Bnip3-required mitophagy. Functional studies showed that Sirt3 reversed Bnip3 expression and mitophagy activity via the ERK-CREB signalling pathway. Blockade of the ERK-CREB axis repressed the promotive effects of Sirt3 on Bnip3 activation and mitophagy augmentation, finally negating the anti-apoptotic influences of Sirt3 on hepatocytes in the setting of high-fat-stress. Collectively, our data show that high-fat-mediated liver damage is associated with Sirt3 downregulation, which is followed by ERK-CREB pathway inactivation and Bnip3-mediated inhibition of mitophagy, causing hepatocytes to undergo mitochondria-dependent cell death. Based on this, strategies for enhancing Sirt3 activity and activating the ERK-CREB-Bnip3-mitophagy pathways could be used to treat nonalcoholic fatty liver disease.
    Keywords:  Bnip3; ERK-CREB signalling pathway; Mitophagy; Nonalcoholic fatty liver disease; Sirt3
  7. Toxicol Lett. 2018 Jul 25. pii: S0378-4274(18)31534-0. [Epub ahead of print]
    Zhao X, Jin Y, Yang L, Hou Z, Liu Y, Sun T, Pei J, Li J, Yao C, Wang X, Chen G.
      Antimony (Sb) has been reported to lead to pulmonary damage, but the underlying mechanism remains unclear. Accumulating evidence indicates that silent mating type information regulation 2 homolog 1 (SIRT1), an NAD+-dependent deacetylase, mediates stimuli-induced cellular apoptosis. Here, we investigated whether SIRT1 plays a role in Sb-triggered apoptosis in human bronchial epithelial cells (BEAS-2b). First, we showed that Sb initiated apoptosis. Furthermore, the expression of SIRT1 was markedly downregulated by Sb treatment, while overexpression of SIRT1 through resveratrol treatment or transfection with SIRT1-Flag plasmid attenuated the Sb-induced apoptosis. Accelerated degradation of SIRT1 protein and lower SIRT1 gene expression contributed to low expression of SIRT1. In addition, Sb activated the ERK and JNK pathways; however, inhibition of ERK rather than JNK rescued SIRT1 suppression. Subsequent analyses demonstrated that antioxidant N-acetylcysteine (NAC) attenuated SIRT1 repression, increased SIRT1 mRNA levels and decreased SIRT1 protein degradation in Sb-treated cells. In addition, NAC also inhibited JNK and ERK activation by Sb exposure. These data suggest that reactive oxygen species-dependent SIRT1 suppression mediates Sb-stimulated cell apoptosis in BEAS-2b cells via lower SIRT1 gene expression and protein stability.
    Keywords:  Antimony; Apoptosis; Pulmonary toxicity; ROS; SIRT1
  8. Chem Biol Interact. 2018 Jul 27. pii: S0009-2797(18)30124-8. [Epub ahead of print]
    Dasgupta N, Ranjan S, Mishra D, Ramalingam C.
      Silver nanoparticles (AgNPs) are being commercialized in a number of consumer products including food and cosmetics where there is a direct exposure of AgNPs to human body. An extensive toxicological evaluation is necessary to understand the mechanism for its safe use, since the toxicity effect varies greatly with the synthesis protocol followed. In this study, we report the detailed toxicological analysis of AgNPs fabricated by thermal co-reduction approach. Our study was analysed in human colon cancer cell line (HCT 116) and the IC50 was calculated as 28.11 μg/ml. It was also observed that AgNP induces oxidative stress on HCT116 by increased levels of lipid peroxidation and reduced levels of glutathione. Mitochondrial membrane depolarization was also analysed and Western blot analysis confirms the increased level of Bcl and Caspase-3 which indicates the mitochondrial -mediated apoptosis. Additionally, flow cytometric analysis suggests cell cycle arrest in G2/M phase. Thus, our study can be a basis for further research to design safe AgNPs in various consumer products. Additionally, similar research can be conducted for different size and shape of AgNP or nano-silver can be engineered using different approaches.
    Keywords:  Colon cancer cell line; Mechanism of action; Silver nanoparticle; Thermal co-reduction; Toxicity
  9. Biochem Biophys Res Commun. 2018 Jul 23. pii: S0006-291X(18)31589-4. [Epub ahead of print]
    Chi J, Yu S, Liu C, Zhao X, Zhong J, Liang Y, Ta N, Yin X, Zhao D.
      Viral myocarditis is a cardiovascular disease that seriously affects human health. Its mechanism is not clear. Coxsackievirus B3 (CVB3) is a member of the picornavirus family and is the leading cause of viral myocarditis. Our group tested the genes in a mouse model of CVB3 virus infection and confirmed that the NADPH oxidase gene had a high expression trend in the acute phase of infection. Whether Nox4, the homologue of NADPH oxidase, participates in the process of viral myocarditis has not been reported. In this study, we found increased expression of Nox4 in viral myocarditis in vivo and in vitro. DPI is a non-specific inhibitor of Nox4 that improved CVB3-induced myocarditis after injection in vivo. DPI also inhibited intracellular ROS release and apoptosis in vitro. Our data indicated that Nox4-dependent ROS production was involved in CVB3-induced myocardial apoptosis.
    Keywords:  Apoptosis; CVB(3); Nox4; ROS; Viral myocarditis
  10. Ecotoxicol Environ Saf. 2018 Jul 26. pii: S0147-6513(18)30662-6. [Epub ahead of print]163 298-306
    Yin J, Liu R, Jian Z, Yang D, Pu Y, Yin L, Wang D.
      Di-(2-ethylhexyl) phthalate (DEHP) is a widely used plasticizer with a high environmental exposure level. As a persistent organic pollutant, DEHP causes reproductive and developmental toxicity in mammals. In this paper, the reproductive toxicity of DEHP was discussed using the model organism Caenorhabditis elegans to determine the sensitivity indices for evaluating the ecotoxicological effects of DEHP. L4 C. elegans larvae to evaluate the LC50 of DEHP and the changes in brood size and generation time, we found that the LC50 of DEHP to C. elegans exceeded 100 mg/L. And 10 mg/L DEHP exposure significantly reduced the brood sizes but not the generation time. Results of oocyte and distal-tip cell (DTC) counting suggested that the number of oocytes were decreased and apoptotic cells that from the unilateral gonad arm were increased in the 1 mg/L and 10 mg/L DEHP exposed groups. In contrast, there was no significant difference in the fluorescence intensity of DTC. Fluorescence analysis of HUS-1 showed that HUS-1 protein was overexpressed after DEHP exposure. The H2O2 level and DNA damage were measured by Bradford protein assay and AP staining respectively. The results showed that there was no significant difference in H2O2 level after DEHP exposure, in contrast, DNA damage was increased significantly. Moreover, 10 mg/L concentration DEHP exposure significantly increased the expression levels of apoptosis-related genes cep-1, egl-1, ced-4, and ced-3 and decreased the expression levels of ced-9. It suggested that cep-1, egl-1, ced-4, and ced-3 genes promote apoptosis and the ced-9 gene inhibits apoptosis. Meanwhile, 10 mg/L concentration DEHP exposure decreased the expression of oxidative stress-related genes mev-1 and gas-1. The mev-1 and gas-1 are mainly involved in the inhibition of oxidative stress in nematodes. In short, the decreased oocyte numbers and increased apoptosis oocyte numbers in C. elegans when exposed to DEHP, which may involve in the DNA damage induced by oxidative stress.
    Keywords:  Caenorhabditis elegans; Ecotoxicological effect; Endocrine disruptor; Germ cells; Oogenesis
  11. Lipids Health Dis. 2018 Jul 28. 17(1): 178
    Tiao MM, Lin YJ, Yu HR, Sheen JM, Lin IC, Lai YJ, Tain YL, Huang LT, Tsai CC.
      BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) can develop in prenatal stages and can be exacerbated by exposure to a postnatal high-fat (HF) diet. We investigated the protective effects of resveratrol on prenatal and postnatal HF diet-induced NAFLD.METHODS: Male Sprague-Dawley rat offspring were placed in five experimental groups (n = 10-12 per group): normal diet (VNF), maternal HF diet (ONF), postnatal HF diet (VHF), and maternal HF diet/postnatal HF diet (OHF). A therapeutic group with resveratrol for maternal HF diet/postnatal HF diet (OHFR) was used for comparison. Resveratrol (50 mg/kg/day) was dissolved in drinking water for offspring from post-weaning to postnatal day (PND) 120.
    RESULTS: We found that HF/HF-induced NAFLD was prevented in adult offspring by the administration of resveratrol. Resveratrol administration mediated a protective effect on rats on HF/HF by regulating lipid metabolism, reducing oxidative stress and apoptosis, restoring nutrient-sensing pathways by increasing Sirt1 and leptin expression, and mediating the renin-angiotensin system (RAS) to decrease angiotensinogen, renin, ACE1, and AT1R levels and increased ACE2, AT2R and MAS1 levels compared to those in the OHF group.
    CONCLUSION: Our results suggest that a maternal and post-weaning HF diet increases liver steatosis and apoptosis via the RAS. Resveratrol might serve as a therapeutic target by mediating protective actions against NAFLD in offspring exposed to a combination of maternal and postnatal HF diet.
    Keywords:  High-fat diet; Nonalcoholic fatty liver disease (NAFLD); Renin-angiotensin system (RAS); Resveratrol