Synphilin-1 Enhances α-Synuclein Aggregation in Yeast and Contributes to Cellular Stress and Cell Death in a Sir2-Dependent Manner

Objective: Cell resistance to doxorubicin and its toxicity to healthy tissue reduce its efficiency. The use of cell-penetrating peptides as drug delivery system along with doxorubicin is a strategy to reduce its side effects. In this study, the influence of poly-L-arginine on doxorubicin cytotoxicity, its cellular uptake and doxorubicin-induced apoptosis on human prostate cancer DU145 cells are assessed. Methods: The cytotoxicity of doxorubicin and poly-L-arginine, alone and in combination, in DU145 cells was evaluated at different exposure times using MTT assay. The influence of poly-L-arginine on doxorubicin delivery into cells was evaluated by fluorescence microscopy and ultraviolet spectroscopy. DAPI and ethidium bromide- acridine orange stainings, flow cytometry using annexin V/propidium iodide, western blot analysis with anti-p21 antibody and caspase-3 activity were used to examine the influence of poly-L-arginine on doxorubicininduced cell death. Results: Poly-L-arginine had no cytotoxicity at low concentrations and short exposure times. Poly-L-arginine increased the cytotoxic effect of doxorubicin in DU145 cells in a time-dependent manner. But no significant reduction was found in HFF cell viability. Poly-L-arginine seems to facilitate doxorubicin uptake and increase its intracellular concentration. 24h combined treatment of cells with doxorubicin (0.5 µM) and poly-L-arginine (1 µg ml-1) caused a small increase in doxorubicin-induced apoptosis and significantly elevated necrosis in DU145 cells as compared to each agent alone. Conclusion: Our results indicate that poly-L-arginine at lowest and highest concentrations act as proliferationinducing and antiproliferative agents, respectively. Between these concentrations, poly-L-arginine increases the cellular uptake of doxorubicin and its cytotoxicity through induction of necrosis.

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Human Neuronal Cell Lines as An In Vitro Toxicological Tool for the Evaluation of Novel Psychoactive Substances

International Journal of Molecular Sciences ◽

10.3390/ijms22136785 ◽

2021 ◽

Vol 22 (13) ◽

pp. 6785

Author(s):

Valeria Sogos ◽

Paola Caria ◽

Clara Porcedda ◽

Rafaela Mostallino ◽

Franca Piras ◽

...

Keyword(s):

Cell Death ◽

Neuronal Cell ◽

In Vitro Study ◽

Dependent Manner ◽

Novel Psychoactive Substances ◽

Psychoactive Substances ◽

Concentration Dependent Manner ◽

Mechanisms Of Toxicity ◽

Neuronal Cell Lines

Novel psychoactive substances (NPS) are synthetic substances belonging to diverse groups, designed to mimic the effects of scheduled drugs, resulting in altered toxicity and potency. Up to now, information available on the pharmacology and toxicology of these new substances is very limited, posing a considerable challenge for prevention and treatment. The present in vitro study investigated the possible mechanisms of toxicity of two emerging NPS (i) 4′-methyl-alpha-pyrrolidinoexanophenone (3,4-MDPHP), a synthetic cathinone, and (ii) 2-chloro-4,5-methylenedioxymethamphetamine (2-Cl-4,5-MDMA), a phenethylamine. In addition, to apply our model to the class of synthetic opioids, we evaluated the toxicity of fentanyl, as a reference compound for this group of frequently abused substances. To this aim, the in vitro toxic effects of these three compounds were evaluated in dopaminergic-differentiated SH-SY5Y cells. Following 24 h of exposure, all compounds induced a loss of viability, and oxidative stress in a concentration-dependent manner. 2-Cl-4,5-MDMA activates apoptotic processes, while 3,4-MDPHP elicits cell death by necrosis. Fentanyl triggers cell death through both mechanisms. Increased expression levels of pro-apoptotic Bax and caspase 3 activity were observed following 2-Cl-4,5-MDMA and fentanyl, but not 3,4-MDPHP exposure, confirming the different modes of cell death.

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The Novel ALG-2 Target Protein CDIP1 Promotes Cell Death by Interacting with ESCRT-I and VAPA/B

International Journal of Molecular Sciences ◽

10.3390/ijms22031175 ◽

2021 ◽

Vol 22 (3) ◽

pp. 1175

Author(s):

Ryuta Inukai ◽

Kanako Mori ◽

Keiko Kuwata ◽

Chihiro Suzuki ◽

Masatoshi Maki ◽

...

Keyword(s):

Cell Death ◽

Essential Gene ◽

Susceptibility Gene ◽

Target Protein ◽

Hek293 Cells ◽

Dependent Manner ◽

Gene Encoding ◽

Endosomal Sorting ◽

Cell Death Pathways ◽

Apoptotic Protein

Apoptosis-linked gene 2 (ALG-2, also known as PDCD6) is a member of the penta-EF-hand (PEF) family of Ca2+-binding proteins. The murine gene encoding ALG-2 was originally reported to be an essential gene for apoptosis. However, the role of ALG-2 in cell death pathways has remained elusive. In the present study, we found that cell death-inducing p53 target protein 1 (CDIP1), a pro-apoptotic protein, interacts with ALG-2 in a Ca2+-dependent manner. Co-immunoprecipitation analysis of GFP-fused CDIP1 (GFP-CDIP1) revealed that GFP-CDIP1 associates with tumor susceptibility gene 101 (TSG101), a known target of ALG-2 and a subunit of endosomal sorting complex required for transport-I (ESCRT-I). ESCRT-I is a heterotetrameric complex composed of TSG101, VPS28, VPS37 and MVB12/UBAP1. Of diverse ESCRT-I species originating from four VPS37 isoforms (A, B, C, and D), CDIP1 preferentially associates with ESCRT-I containing VPS37B or VPS37C in part through the adaptor function of ALG-2. Overexpression of GFP-CDIP1 in HEK293 cells caused caspase-3/7-mediated cell death. In addition, the cell death was enhanced by co-expression of ALG-2 and ESCRT-I, indicating that ALG-2 likely promotes CDIP1-induced cell death by promoting the association between CDIP1 and ESCRT-I. We also found that CDIP1 binds to vesicle-associated membrane protein-associated protein (VAP)A and VAPB through the two phenylalanines in an acidic tract (FFAT)-like motif in the C-terminal region of CDIP1, mutations of which resulted in reduction of CDIP1-induced cell death. Therefore, our findings suggest that different expression levels of ALG-2, ESCRT-I subunits, VAPA and VAPB may have an impact on sensitivity of anticancer drugs associated with CDIP1 expression.

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Crosstalk of the Caspase Family and Mammalian Target of Rapamycin Signaling

International Journal of Molecular Sciences ◽

10.3390/ijms22020817 ◽

2021 ◽

Vol 22 (2) ◽

pp. 817

Author(s):

Junfang Yan ◽

Yi Xie ◽

Jing Si ◽

Lu Gan ◽

Hongyan Li ◽

...

Keyword(s):

Cell Growth ◽

Cell Survival ◽

Cell Fate ◽

Cellular Stress ◽

Mammalian Target Of Rapamycin ◽

Mtor Signaling ◽

Target Of Rapamycin ◽

Dependent Manner ◽

Caspase Family ◽

Mediate Cell

Cell can integrate the caspase family and mammalian target of rapamycin (mTOR) signaling in response to cellular stress triggered by environment. It is necessary here to elucidate the direct response and interaction mechanism between the two signaling pathways in regulating cell survival and determining cell fate under cellular stress. Members of the caspase family are crucial regulators of inflammation, endoplasmic reticulum stress response and apoptosis. mTOR signaling is known to mediate cell growth, nutrition and metabolism. For instance, over-nutrition can cause the hyperactivation of mTOR signaling, which is associated with diabetes. Nutrition deprivation can inhibit mTOR signaling via SH3 domain-binding protein 4. It is striking that Ras GTPase-activating protein 1 is found to mediate cell survival in a caspase-dependent manner against increasing cellular stress, which describes a new model of apoptosis. The components of mTOR signaling-raptor can be cleaved by caspases to control cell growth. In addition, mTOR is identified to coordinate the defense process of the immune system by suppressing the vitality of caspase-1 or regulating other interferon regulatory factors. The present review discusses the roles of the caspase family or mTOR pathway against cellular stress and generalizes their interplay mechanism in cell fate determination.

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Cell Death and Metabolic Stress in Gymnodinium catenatum Induced by Allelopathy

Toxins ◽

10.3390/toxins13070506 ◽

2021 ◽

Vol 13 (7) ◽

pp. 506

Author(s):

Leyberth José Fernández-Herrera ◽

Christine Johanna Band-Schmidt ◽

Tania Zenteno-Savín ◽

Ignacio Leyva-Valencia ◽

Claudia Judith Hernández-Guerrero ◽

...

Keyword(s):

Cell Death ◽

Programmed Cell Death ◽

Protein Content ◽

Caspase 3 ◽

Cellular Stress ◽

Allelopathic Effect ◽

Sod Activity ◽

Free Media ◽

O2 Production ◽

Gymnodinium Catenatum

Allelopathy between phytoplankton species can promote cellular stress and programmed cell death (PCD). The raphidophyte Chattonella marina var. marina, and the dinoflagellates Margalefidinium polykrikoides and Gymnodinium impudicum have allelopathic effects on Gymnodinium catenatum; however, the physiological mechanisms are unknown. We evaluated whether the allelopathic effect promotes cellular stress and activates PCD in G. catenatum. Cultures of G. catenatum were exposed to cell-free media of C. marina var. marina, M. polykrikoides and G. impudicum. The mortality, superoxide radical (O2●−) production, thiobarbituric acid reactive substances (TBARS) levels, superoxide dismutase (SOD) activity, protein content, and caspase-3 activity were quantified. Mortality (between 57 and 79%) was registered in G. catenatum after exposure to cell-free media of the three species. The maximal O2●− production occurred with C. marina var. marina cell-free media. The highest TBARS levels and SOD activity in G. catenatum were recorded with cell-free media from G. impudicum. The highest protein content was recorded with cell-free media from M. polykrikoides. All cell-free media caused an increase in the activity of caspase-3. These results indicate that the allelopathic effect in G. catenatum promotes cell stress and caspase-3 activation, as a signal for the induction of programmed cell death.

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Pyrrolizidine Alkaloids Induce Cell Death in Human HepaRG Cells in a Structure-Dependent Manner

International Journal of Molecular Sciences ◽

10.3390/ijms22010202 ◽

2020 ◽

Vol 22 (1) ◽

pp. 202

Author(s):

Josephin Glück ◽

Julia Waizenegger ◽

Albert Braeuning ◽

Stefanie Hessel-Pras

Keyword(s):

Cell Death ◽

Cell Viability ◽

Pyrrolizidine Alkaloids ◽

Defense Mechanism ◽

Hepatoma Cell ◽

Hepatoma Cell Line ◽

Dependent Manner ◽

Human Hepatoma Cell

Pyrrolizidine alkaloids (PAs) are a group of secondary metabolites produced in various plant species as a defense mechanism against herbivores. PAs consist of a necine base, which is esterified with one or two necine acids. Humans are exposed to PAs by consumption of contaminated food. PA intoxication in humans causes acute and chronic hepatotoxicity. It is considered that enzymatic PA toxification in hepatocytes is structure-dependent. In this study, we aimed to elucidate the induction of PA-induced cell death associated with apoptosis activation. Therefore, 22 structurally different PAs were analyzed concerning the disturbance of cell viability in the metabolically competent human hepatoma cell line HepaRG. The chosen PAs represent the main necine base structures and the different esterification types. Open-chained and cyclic heliotridine- and retronecine-type diesters induced strong cytotoxic effects, while treatment of HepaRG with monoesters did not affect cell viability. For more detailed investigation of apoptosis induction, comprising caspase activation and gene expression analysis, 14 PA representatives were selected. The proapoptotic effects were in line with the potency observed in cell viability studies. In vitro data point towards a strong structure–activity relationship whose effectiveness needs to be investigated in vivo and can then be the basis for a structure-associated risk assessment.

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Ferroptosis contributes to isoflurane-induced neurotoxicity and learning and memory impairment

Cell Death Discovery ◽

10.1038/s41420-021-00454-8 ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Pengfei Liu ◽

Jing Yuan ◽

Yetong Feng ◽

Xin Chen ◽

Guangsuo Wang ◽

...

Keyword(s):

Cell Death ◽

Learning And Memory ◽

Memory Impairment ◽

Close Association ◽

Dimethyl Fumarate ◽

Dependent Manner ◽

Transport Chain ◽

The Relationship

AbstractFerroptosis is a novel type of programmed cell death, which is different from apoptosis and autophagic cell death. Recently, ferroptosis has been indicated to contribute to the in vitro neurotoxicity induced by isoflurane, which is one of the most common anesthetics in clinic. However, the in vivo position of ferroptosis in isoflurane-induced neurotoxicity as well as learning and memory impairment remains unclear. In this study, we mainly explored the relationship between ferroptosis and isoflurane-induced learning and memory, as well as the therapeutic methods in mouse model. Our results indicated that isoflurane induced the ferroptosis in a dose-dependent and time-dependent manner in hippocampus, the organ related with learning and memory ability. In addition, the activity of cytochrome c oxidase/Complex IV in mitochondrial electron transport chain (ETC) was increased by isoflurane, which might further contributed to cysteine deprivation-induced ferroptosis caused by isoflurane exposure. More importantly, isoflurane-induced ferroptosis could be rescued by both ferroptosis inhibitor (ferrostatin-1) and mitochondria activator (dimethyl fumarate), which also showed effective therapeutic action against isoflurane-induced learning and memory impairment. Taken together, our data indicate the close association among ferroptosis, mitochondria and isoflurane, and provide a novel insight into the therapy mode against isoflurane-induced learning and memory impairment.

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DNase II mediates a parthanatos-like developmental cell death pathway in Drosophila primordial germ cells

Nature Communications ◽

10.1038/s41467-021-22622-1 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Lama Tarayrah-Ibraheim ◽

Elital Chass Maurice ◽

Guy Hadary ◽

Sharon Ben-Hur ◽

Alina Kolpakova ◽

...

Keyword(s):

Dna Damage ◽

Cell Death ◽

Germ Cells ◽

Nuclear Translocation ◽

Primordial Germ Cells ◽

Nuclear Accumulation ◽

Dependent Manner ◽

Dnase Ii ◽

Cell Death Pathway ◽

Parp 1

AbstractDuring Drosophila embryonic development, cell death eliminates 30% of the primordial germ cells (PGCs). Inhibiting apoptosis does not prevent PGC death, suggesting a divergence from the conventional apoptotic program. Here, we demonstrate that PGCs normally activate an intrinsic alternative cell death (ACD) pathway mediated by DNase II release from lysosomes, leading to nuclear translocation and subsequent DNA double-strand breaks (DSBs). DSBs activate the DNA damage-sensing enzyme, Poly(ADP-ribose) (PAR) polymerase-1 (PARP-1) and the ATR/Chk1 branch of the DNA damage response. PARP-1 and DNase II engage in a positive feedback amplification loop mediated by the release of PAR polymers from the nucleus and the nuclear accumulation of DNase II in an AIF- and CypA-dependent manner, ultimately resulting in PGC death. Given the anatomical and molecular similarities with an ACD pathway called parthanatos, these findings reveal a parthanatos-like cell death pathway active during Drosophila development.

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Inflammatory process, cellular stress and cell death in pancreatic acinar cells in response to toxic factors

Pancreatology ◽

10.1016/j.pan.2013.07.013 ◽

2013 ◽

Vol 13 (4) ◽

pp. e4

Author(s):

M. Luaces-Regueira ◽

M. Castiñeira-Alvariño ◽

J.E. Domínguez-Muñoz

Keyword(s):

Cell Death ◽

Inflammatory Process ◽

Cellular Stress ◽

Acinar Cells ◽

Pancreatic Acinar Cells ◽

Toxic Factors

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Role of Hypoxia-Mediated Autophagy in Tumor Cell Death and Survival

Cancers ◽

10.3390/cancers13030533 ◽

2021 ◽

Vol 13 (3) ◽

pp. 533

Author(s):

Rania F. Zaarour ◽

Bilal Azakir ◽

Edries Y. Hajam ◽

Husam Nawafleh ◽

Nagwa A. Zeinelabdin ◽

...

Keyword(s):

Cell Death ◽

Type I ◽

Dependent Manner ◽

Destruction Process ◽

Tumor Cell Death ◽

Complex Regulation ◽

Cancer Immunotherapies ◽

The Relationship ◽

Shed Light

Programmed cell death or type I apoptosis has been extensively studied and its contribution to the pathogenesis of disease is well established. However, autophagy functions together with apoptosis to determine the overall fate of the cell. The cross talk between this active self-destruction process and apoptosis is quite complex and contradictory as well, but it is unquestionably decisive for cell survival or cell death. Autophagy can promote tumor suppression but also tumor growth by inducing cancer-cell development and proliferation. In this review, we will discuss how autophagy reprograms tumor cells in the context of tumor hypoxic stress. We will illustrate how autophagy acts as both a suppressor and a driver of tumorigenesis through tuning survival in a context dependent manner. We also shed light on the relationship between autophagy and immune response in this complex regulation. A better understanding of the autophagy mechanisms and pathways will undoubtedly ameliorate the design of therapeutics aimed at targeting autophagy for future cancer immunotherapies.

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