scholarly journals SIRT3-SOD2-ROS pathway is involved in Linalool-induced glioma cell apoptotic death

2017 ◽  
Vol 64 (2) ◽  
Author(s):  
Yanhao Cheng ◽  
Chao Dai ◽  
Jian Zhang

Glioma is the most prevalent type of adult primary brain tumor and chemotherapy of glioma was limited by drug-resistance. Linalool is an acyclic monoterpene alcohol possessing various pharmacological activities. The present study was conducted to evaluate the effect of Linalool on glioma cell growth. The effect of Linalool on U87-MG cells was investigated and the results showed that Linalool significantly reduced cell viability in U87-MG cells in a concentration and time-dependent manner. In addition, exposure of cells to Linalool resulted in concentration-dependent increase of TUNEL-stained cells, indicating the occurrence of apoptotic cell death. Linalool decreased mitochondrial oxygen consumption rate, increased the expression of Bax and Bcl-2, reduced the expression of Bcl-2 and Bcl-xl, and increased the activities of caspase 3 and caspase 9, leading to increase of apoptosis. Linalool resulted in a concentration-dependent decrease of SOD activity but had no significant effect on the mRNA and protein expression of SOD2. Moreover, Linalool resulted in a significant increase of acetylated SOD2. The mRNA and protein expression of SIRT3 was significantly inhibited by Linalool. Immunoblot analysis showed that there were protein/protein interaction of SOD2 and SIRT3 in control U87-MG cells. Linalool treatment significantly decreased the interaction of SOD2 and SIRT3. Overexpression of SIRT3 significantly inhibited Linalool-induced increase of mitochondrial ROS level, apoptotic cell death and decrease of cell viability. In summary, we found that Linalool exhibited inhibitory effect on glioma cells through regulation of SIRT3-SOD2-ROS signaling.

2020 ◽  
Author(s):  
Xiaoqing Liu ◽  
Shuqi Wang ◽  
Hao Zheng ◽  
Qingying Liu ◽  
Tao Shen ◽  
...  

Abstract Background: Methuosis is a novel type of non-apoptotic cell death characterized by accumulation of cytoplasmic vacuoles. Identification of molecules that induce methuosis may provide alternative therapeutics for cancers that are refractory to apoptosis. Epimedokoreanin C (EKC) is a prenylated flavonoid isolated from a Chinese herb Epimedium koreanum. Methods: In this study, MTT assay, real-time cell analysis monitoring of cell growth and wound-healing assay were used for cell viability and migration evaluation. Flow cytometry was performed to assess apoptosis. Immunoblot analysis, immunofluorescence, pull-down assays and live cell imaging with fluorescent tracers were utilized to evaluate the regulation of signaling pathways.Results: EKC reduced cell viability accompanied by extreme vacuolation in lung cancer NCI-H292 cells. The EKC-induced cell death was clarified as non-apoptosis based on the absence of apoptotic changes. The vacuoles stimulated by EKC were supposed to be derived from macropinocytosis based on the engulfment of extracellular fluid tracer, Lucifer Yellow. The vacuoles acquired some characteristics of late endosomes supported that EKC-induced cell death could be described as methuosis. Rac1 and Arf6 were found to be regulated inversely after EKC treatment. Blocking Rac1 activation with the specific Rac1 inhibitor EHT 1864 prevented the accumulation of vacuoles induced by EKC markedly, suggested that the regulation of Rac1 and Arf6 was at least partial mechanism involved in EKC induced methuosis. EKC synergized the effects of doxorubicin and etoposide, demonstrating the effectiveness of using EKC to synergize conventional chemotherapy. Conclusions: Collectively, EKC was demonstrated as a methuosis-like cell death inducer in NCI-H292 cells. It has the potential to be used as an attractive prototype for developing drugs that could kill apoptosis-resistant cancer cells.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sachin Sharma ◽  
Shaikh Maryam Ghufran ◽  
Sampa Ghose ◽  
Subhrajit Biswas

AbstractThe activated hepatic stellate cells (HSCs) are the major cells that secrete the ECM proteins and drive the pathogenesis of fibrosis in chronic liver disease. Targeting of HSCs by modulating their activation and proliferation has emerged as a promising approach in the development of anti-fibrotic therapy. Sorafenib, a multi-kinase inhibitor has shown anti-fibrotic properties by inhibiting the survival and proliferation of HSCs. In present study we investigated sorafenib induced cytoplasmic vacuolation mediated decreased cell viability of HSCs in dose and time dependent manner. In this circumstance, sorafenib induces ROS and ER stress in HSCs without involvement of autophagic signals. The protein synthesis inhibitor cycloheximide treatment significantly decreased the sorafenib-induced cytoplasmic vacuolation with increasing cell viability. Antioxidant human serum albumin influences the viability of HSCs by reducing sorafenib induced vacuolation and cell death. However, neither caspase inhibitor Z-VAD-FMK nor autophagy inhibitor chloroquine could rescue the HSCs from sorafenib-induced cytoplasmic vacuolation and cell death. Using TEM and ER organelle tracker, we conclude that the cytoplasmic vacuoles are due to ER dilation. Sorafenib treatment induces calreticulin and GPR78, and activates IRE1α-XBP1s axis of UPR pathway, which eventually trigger the non-apoptotic cell death in HSCs. This study provides a notable mechanistic insight into the ER stress directed non-apoptotic cell death with future directions for the development of efficient anti-fibrotic therapeutic strategies.


2021 ◽  
Author(s):  
Amy Tarangelo ◽  
Joon Tae Kim ◽  
Jonathan Z Long ◽  
Scott J Dixon

Nucleotide synthesis is a metabolically demanding process essential for cell division. Several anti-cancer drugs that inhibit nucleotide metabolism induce apoptosis. How inhibition of nucleotide metabolism impacts non-apoptotic cell death is less clear. Here, we report that inhibition of nucleotide metabolism by the p53 pathway is sufficient to suppress the non-apoptotic cell death process of ferroptosis. Mechanistically, stabilization of wild-type p53 and induction of the p53 target gene CDKN1A (p21) leads to decreased expression of the ribonucleotide reductase (RNR) subunits RRM1 and RRM2. RNR is the rate-limiting enzyme of de novo nucleotide synthesis that reduces ribonucleotides to deoxyribonucleotides in a glutathione-dependent manner. Direct inhibition of RNR conserves glutathione which can then be used to limit the accumulation of toxic lipid peroxides, preventing the onset of ferroptosis. These results support a mechanism linking p53-dependent regulation of nucleotide metabolism to non-apoptotic cell death.


2015 ◽  
Vol 84 (1) ◽  
pp. 172-186 ◽  
Author(s):  
Moo-Seung Lee ◽  
Haenaem Kwon ◽  
Eun-Young Lee ◽  
Dong-Jae Kim ◽  
Jong-Hwan Park ◽  
...  

Shiga toxin (Stx)-mediated immune responses, including the production of the proinflammatory cytokines tumor necrosis-α (TNF-α) and interleukin-1β (IL-1β), may exacerbate vascular damage and accelerate lethality. However, the immune signaling pathway activated in response to Stx is not well understood. Here, we demonstrate that enzymatically active Stx, which leads to ribotoxic stress, triggers NLRP3 inflammasome-dependent caspase-1 activation and IL-1β secretion in differentiated macrophage-like THP-1 (D-THP-1) cells. The treatment of cells with a chemical inhibitor of glycosphingolipid biosynthesis, which suppresses the expression of the Stx receptor globotriaosylceramide and subsequent endocytosis of the toxin, substantially blocked activation of the NLRP3 inflammasome and processing of caspase-1 and IL-1β. Processing and release of both caspase-1 and IL-1β were significantly reduced or abolished in Stx-intoxicated D-THP-1 cells in which the expression of NLRP3 or ASC was stably knocked down. Furthermore, Stx mediated the activation of caspases involved in apoptosis in an NLRP3- or ASC-dependent manner. In Stx-intoxicated cells, the NLRP3 inflammasome triggered the activation of caspase-8/3, leading to the initiation of apoptosis, in addition to caspase-1-dependent pyroptotic cell death. Taken together, these results suggest that Stxs trigger the NLRP3 inflammasome pathway to release proinflammatory IL-1β as well as to promote apoptotic cell death.


2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Prachya Janhom ◽  
Permphan Dharmasaroja

In vitrostudies have shown that extracts from mangosteen (Garcinia mangostanaLinn.) act as antioxidants and cytoprotective agents against oxidative damage. The protective effect of alpha-mangostin, the major xanthone found in the pericarp of the mangosteen, in cellular models of Parkinson’s disease (PD), has not been investigated. This study aims to investigate whether alpha-mangostin could protect SH-SY5Y neuroblastoma cells from MPP+-induced apoptosis. The effects of alpha-mangostin on MPP+-induced cell death were evaluated with a cell viability assay, staining for nuclear DNA morphology, flow cytometry for apoptotic cells and reactive oxygen species (ROS) production, quantitative real-time PCR for the expression of p53, Bax, and Bcl-2, and western blot analysis for cleaved caspase-3. Concomitant treatment with alpha-mangostin attenuated the effect of MPP+on cell viability and apoptotic cell death. Alpha-mangostin reduced ROS formation induced by MPP+. Bax/Bcl-2 expression ratio and expression of p53 were significantly lower in cells cocultured with alpha-mangostin and MPP+. The cotreated cells showed a significant decrease in activated caspase-3 compared with MPP+treatment alone. Our data suggest that cytoprotection of alpha-mangostin against MPP+-induced apoptosis may be associated with the reduction of ROS production, modulating the balance of pro- and antiapoptotic genes, and suppression of caspase-3 activation.


2005 ◽  
Vol 86 (9) ◽  
pp. 2513-2523 ◽  
Author(s):  
Chia-Che Chang ◽  
Yen-Chuan Ou ◽  
Shue-Ling Raung ◽  
Chun-Jung Chen

Japanese encephalitis virus (JEV), which causes neurological disorders, completes its life cycle and triggers apoptotic cell death in infected cells. Dehydroepiandrosterone (DHEA), an adrenal-derived steroid, has been implicated in protection against neurotoxicity and protection of animals from viral-induced encephalitis, resulting in an increased survival rate of the animals. Currently, the mechanisms underlying the beneficial effects of DHEA against the virus are largely unknown. In this study, DHEA suppression of JEV replication and virus-induced apoptosis in murine neuroblastoma (N18) cells was investigated. It was found that DHEA suppressed JEV-induced cytopathic effects, JEV-induced apoptotic cell death and JEV propagation in a concentration-dependent manner. Antiviral activity was more efficient in cultures treated with DHEA immediately after viral adsorption compared with that in cultures receiving delayed administration after adsorption or transient exposure before adsorption. JEV-induced cytotoxicity was accompanied by the inactivation of extracellular signal-regulated protein kinase (ERK). Inactivation of ERK by JEV infection was reversed by DHEA. When cells were treated with the ERK inhibitor U0126, DHEA lost its antiviral effect. Activation of ERK by anisomycin mimicked the action of DHEA in suppressing JEV-induced cytotoxicity. DHEA-related compounds, such as its sulfate ester (DHEAS) and pregnenolone, were unable to suppress JEV-induced cytotoxicity and ERK inactivation. The hormone-receptor antagonists ICI 182780 and flutamide failed to abrogate the antiviral effect of DHEA. These findings suggest that the antiviral effect of DHEA is not linked directly to the genomic steroid-receptor pathways and suggest that the signalling pathways of ERK play a role in the antiviral action of DHEA.


2006 ◽  
Vol 340 (2) ◽  
pp. 560-566 ◽  
Author(s):  
Yusuke Fujiwara ◽  
Kei Kawada ◽  
Daiki Takano ◽  
Susumu Tanimura ◽  
Kei-ichi Ozaki ◽  
...  

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 1360-1360
Author(s):  
Jieun Jang ◽  
Ju-In Eom ◽  
Hoi-kyung Jeung ◽  
So-Young Seol ◽  
Haerim Chung ◽  
...  

Abstract Background: Histone methyltransferase (HMTase) G9a regulates the transcription of multiple genes by primarily catalyzing dimethylation of histone H3 lysine 9 (H3K9me2), as well as several non-histone lysine sites. Recently, pharmacological and genetic targeting of the G9a was shown to be efficient in slowing down acute myeloid leukemia (AML) cell proliferation in a mouse model and human AML cell lines thus making this HMTase potential target for epigenetic therapy of AML. Activation of adaptive mechanisms to drug plays a crucial role in drug resistance and relapse by allowing cell survival under stressful conditions. Therefore, inhibition of the adaptive response is considered as a prospective therapeutic strategy. The tolerance mechanism to HMTase regulation in leukemia cell is unclear yet. The PERK-eIF2α phosphorylation pathway is an important arm of the unfolded protein response (UPR), which is induced under conditions of endoplasmic reticulum (ER) stress. Recent previous studies showed that pro-survival ER stress is induced in cancer cells and contributes to development of drug resistance. Methods: We investigated the levels of apoptosis and ER stress by G9a inhibitor BIX-01294 in leukemia cell lines. U937, cytarabine-resistant U937 (U937/AR) and KG1 were used. U937/AR cell line was established in our laboratory by exposing parental U937 cells to stepwise increasing concentrations of cytarabine. Results: We initially examined the expression of G9a in leukemia cell lines and the primary AML cells obtained from a patient at the different time point. In U937/AR cells and primary AML cells obtained at relapse, G9a expression was increased compare to that in U937 cells and primary AML cells obtained at diagnosis, respectively. G9a expression was also increased in KG1 cells. In both of U937 and U937/AR, apoptotic cell death was induced by BIX-01294 in a dose-dependent manner. In contrast, apoptotic cell death was minimal in KG1 cells which are enriched in cells expressing a leukemia stem cell phenotype (CD34+CD38-). To address the activation of ER stress response by BIX-01294 in leukemia cells, we examined the effect of BIX-01294 treatment on PERK and eIF2α protein expression and phosphorylation levels. We found that treatment of U937, U937/AR, KG1 cells with 3μM of BIX-01294 for 24h caused an upregulation of phosphorylated PERK and eIF2α. The upregulation of PERK phosphorylation was associated with a decrease in PERK protein levels after treatment. To further address the role of the PERK-eIF2α phosphorylation in BIX-01294 sensitivity, we examined whether PERK inhibition using small interfering RNA (siRNA) or specific inhibitor could sensitize cells to BIX-01294-mediated death. The siRNA against PERK effectively inhibited BIX-01294-mediated phosphorylation of PERK and eIF2α in U937 and U937/AR cells. The addition of PERK siRNA led to a significant increase in the extent of BIX-01294-induced apoptotic cell death in U937 (P = 0.0003) and U937/AR (P < 0.0001) as compared with that of BIX-01294 treatment alone. PERK inhibitor GSK260641 significantly increased BIX-01294-induced apoptotic cell death in U937 (P < 0.0001) and U937/AR (P = 0.006) cells. To our surprise, addition of PERK siRNA or GSK260641 increased the sensitivity of KG1 cells to BIX-01294-mediated death in a dose-dependent manner (P = 0.0003 for siRNA, P = 0.0053 for GSK260641). Conclusion: These data demonstrated that PERK-eIF2α activation has a pro-survival function to G9a inhibitor in leukemia cells and mediates resistance of AML stem cells to G9a inhibitor treatment. The PERK-eIF2α phosphorylation arm may represent a suitable target for combating resistance to G9a inhibitor in AML. The mechanisms underlying the increased sensitivity of AML cells with PERK inhibition to G9a inhibitor are unclear at present and are needed to define in further studies. Disclosures No relevant conflicts of interest to declare.


2001 ◽  
Vol 71 (3) ◽  
pp. 69-78
Author(s):  
Mihaela Buleandra ◽  
Zenovia Moldovan ◽  
Irinel Adriana Badea ◽  
Iulia Gabriela David ◽  
Dana Elena Popa ◽  
...  

Millefolii herba is an available product on the Romanian market as mixture of stems, leaves and flowers of Achillea millefolium L. There were established its volatile compounds profile, total polyphenolic content (TPC), antioxidant capacity and effects on HCT 116 cell viability and programmed cell death. The infusion, hydroalcoholic extract and hydrodistillated essential oil were studied. A comparative analysis using static headspace (HS) and hydro-distillation (HD) GC/MS of the volatile components from Millefolii herba was realized: the essential oil contains chamazulene as the principal component (37.1%), while 1,8-cineole (46.8%) is the main constituent of headspace volatiles. The highest antioxidant capacity was found in essential oil, compared with hydroalcoholic extract, infusion and ascorbic acid. Yarrow hydroalcoholic extract reduced the HCT 116 cell viability and induced the apoptotic cell death in a dose and time dependent manner.


Blood ◽  
2000 ◽  
Vol 95 (11) ◽  
pp. 3483-3488 ◽  
Author(s):  
S. Celeste Posey ◽  
Maria Paola Martelli ◽  
Toshifumi Azuma ◽  
David J. Kwiatkowski ◽  
Barbara E. Bierer

Abstract The actin regulatory protein gelsolin cleaves actin filaments in a calcium- and polyphosphoinositide-dependent manner. Gelsolin has recently been described as a novel substrate of the cysteinyl protease caspase-3, an effector protease activated during apoptosis. Cleavage by caspase-3 generates an amino-terminal fragment of gelsolin that can sever actin filaments independently of calcium regulation. The disruption of the actin cytoskeleton by cleaved gelsolin is hypothesized to mediate many of the downstream morphological changes associated with apoptosis. In contrast, overexpression of full-length gelsolin has also been reported to inhibit apoptotic cell death upstream of the activation of caspase-3, suggesting that gelsolin may also act prior to commitment to cell death. The authors previously observed that actin stabilization by the cell permeant agent jasplakinolide enhanced cell death upon interleukin (IL)-2 or IL-3 withdrawal from growth-factor–dependent lymphocyte cell lines, and hypothesized that actin polymerization could alter the activity of gelsolin, thus enhancing apoptosis. Here the authors show that constitutive overexpression of gelsolin did not, however, inhibit or dramatically enhance apoptotic cell death upon growth-factor withdrawal, nor did it modify sensitivity to jasplakinolide. In contrast to previous reports, overexpression of gelsolin in Jurkat T cells did not prevent or delay apoptosis induced by Fas ligation or ceramide treatment. Overexpressed gelsolin protein was cleaved during apoptosis, as seen previously in this and other cell types. In these model systems, therefore, the level of gelsolin expression was not a rate-limiting determinant in commitment to or time to the morphological changes of apoptosis.


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