scholarly journals Bracovirus sneaks into apoptotic bodies transmitting immunosuppressive signaling driven by integration-mediated eIF5A hypusination

2021 ◽  
Author(s):  
Kaijun Luo
Keyword(s):  
Extracellular Vesicles ◽  
Cell Apoptosis ◽  
Caspase 3 ◽  
Apoptotic Cell ◽  
Recipient Cell ◽  
Nucleocytoplasmic Transport ◽  
Host Cells ◽  
Repair System ◽  
Apoptotic Cell Disassembly ◽  
Cellular Apoptosis

Abstract The typical characteristic of polydnavirus (PDV) infection is persistent immunosuppression, governed by the viral integration and expression of virulence genes. Recently, how Microplitis bicoloratus bracovirus (MbBV) activates caspase-3 to cleave Innexins, gap junction proteins, has been highlighted, further promoting apoptotic cell disassembly and apoptotic body (AB) formation. However, little is known about how inserted viral fragments interact with host cells to drive apoptosis and the role MbBV-mediated extracellular vesicles play in immune suppression. Herein, we show that ABs transmitted immunosuppressive signaling, causing recipient cell apoptosis and dismigration. Overall, viral host integrated motif sites insertion damaged host genome stimulating eIF5A nucleocytoplasmic transport, activating the eIF5A-hypusination translation pathway. Functionally, translated apoptosis-related host proteins, such as P53, CypD, CypJ, and CypA, drive a broken dsDNA cellular apoptosis. Furthermore, translated viral proteins, vank86, 92, and 101, known to complex with transcription factor Dip3, positively regulated DHYS and DOHH transcription maintaining the activation of the eIF5A-hypusination translation pathway. Mechanistically, MbBV-mediated extracellular vesicles contained inserted viral fragments that re-integrated into recipients, potentially via the homologous recombinant repair system. Meanwhile, this stimulation regulated activated caspase-3 level via pI3K/Akt 308 and 473 dephosphorylation to promote recipients cell apoptosis; pI3K/Akt 473 phosphorylation inhibited caspase-3 activation leading to recipient cell dismigration. In conclusion, our results suggest that integration-mediated eIF5A hypusination drives extracellular vesicles for continues immunosuppressive.

scholarly journals c-Jun N-Terminal Kinase 1 Phosphorylates Myt1 To Prevent UVA-Induced Skin Cancer

2009 ◽  
Vol 29 (8) ◽  
pp. 2168-2180 ◽  
Author(s):  
Hong Seok Choi ◽  
Ann M. Bode ◽  
Jung-Hyun Shim ◽  
Sung-Young Lee ◽  
Zigang Dong
Keyword(s):  
Skin Cancer ◽  
Caspase 3 ◽  
Ex Vivo ◽  
Apoptotic Cell ◽  
Uva Irradiation ◽  
Cellular Apoptosis ◽  
Mechanistic Basis ◽  
Induced Apoptosis ◽  
Jnk Isoforms

ABSTRACT The c-Jun N-terminal kinase (JNK) signaling pathway is known to mediate both survival and apoptosis of tumor cells. Although JNK1 and JNK2 have been shown to differentially regulate the development of skin cancer, the underlying mechanistic basis remains unclear. Here, we demonstrate that JNK1, but not JNK2, interacts with and phosphorylates Myt1 ex vivo and in vitro. UVA induces substantial apoptosis in JNK wild-type (JNK +/+) or JNK2-deficient (JNK2 −/−) mouse embryonic fibroblasts but has no effect on JNK1-deficient (JNK1 −/−) cells. In addition, UVA-induced caspase-3 cleavage and DNA fragmentation were suppressed by the knockdown of human Myt1 in skin cancer cells. JNK1 deficiency results in suppressed Myt1 phosphorylation and caspase-3 cleavage in skin exposed to UVA irradiation. In contrast, the absence of JNK2 induces Myt1 phosphorylation and caspase-3 cleavage in skin exposed to UVA. The overexpression of JNK1 with Myt1 promotes cellular apoptosis during the early embryonic development of Xenopus laevis, whereas the presence of JNK2 reduces the phenotype of Myt1-induced apoptotic cell death. Most importantly, JNK1 −/− mice developed more UVA-induced papillomas than either JNK +/+ or JNK2 −/− mice, which was associated with suppressed Myt1 phosphorylation and decreased caspase-3 cleavage. Taken together, these data provide mechanistic insights into the distinct roles of the different JNK isoforms, specifically suggesting that the JNK1-mediated phosphorylation of Myt1 plays an important role in UVA-induced apoptosis and the prevention of skin carcinogenesis.

scholarly journals MicroRNA-155 Promotes Myocardial Infarction-Induced Apoptosis by Targeting RNA-Binding Protein QKI

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Jing Guo ◽  
Hui-Bin Liu ◽  
Chuan Sun ◽  
Xiu-Qing Yan ◽  
Juan Hu ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Cell Apoptosis ◽  
Caspase 3 ◽  
Rna Binding ◽  
Apoptotic Cell ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Cell Number ◽  
Neonatal Rat

Acute myocardial infarction (AMI) is the leading cause of sudden death worldwide. MicroRNA-155 (miR-155) has been reported to target antiapoptotic genes in various diseases models, but the functional role of miR-155 in response to MI injury needs further investigations. This study investigated the role of miR-155 in myocardial ischemia injury. TUNEL and flow cytometry were performed to measure cell apoptosis. Western blot analysis was employed to detect protein expressions of Bcl-2, XIAP, Bax, and caspase-3. qRT-PCR was used to quantify miRNA levels. We showed that miR-155 was dynamically elevated in murine hearts subjected to MI and in neonatal rat ventricular cardiomyocyte (NRVM) injury induced by hydrogen peroxide (H2O2). In response to H2O2, the silencing of miR-155 using AMO-155 (antisense inhibitor oligodeoxyribonucleotides) significantly increased cell viability and reduced cell apoptosis. Moreover, AMO-155 reversed the H2O2-induced downregulation of Bcl-2 and XIAP and upregulation of Bax and cleaved-caspase-3. Further study revealed that AMO-155 resulted in a decrease of H2O2-induced JC-1-labelled monomeric cell number. In addition, AMO-155 markedly decreased infarct size, ameliorated impaired cardiac function, and significantly reduced apoptotic cell percentages in MI mice heart. The RNA-binding protein Quaking (QKI) was predicted as a target gene of miR-155 through bioinformatic analysis, and AMO-155 attenuated the downregulation of QKI in H2O2-treated cardiomyocytes and MI mice heart. Knockdown of QKI by siRNA abolished the antiapoptotic effects of AMO-155. Taken together, miR-155 is upregulated in the MI heart and NRVMs in response to H2O2 stress, and downregulating of miR-155 protects cardiomyocytes against apoptosis. Mechanistically, it is probably due to the repression of QKI signaling pathway.

scholarly journals Role of calcium-independent phospholipase A2β in human pancreatic islet β-cell apoptosis

2012 ◽  
Vol 303 (11) ◽  
pp. E1386-E1395 ◽  
Author(s):  
Xiaoyong Lei ◽  
Sheng Zhang ◽  
Alan Bohrer ◽  
Suzanne E. Barbour ◽  
Sasanka Ramanadham
Keyword(s):  
Er Stress ◽  
Cell Apoptosis ◽  
Caspase 3 ◽  
Apoptotic Cell ◽  
Human Islet ◽  
Β Cells ◽  
Β Cell ◽  
Cell Dysfunction ◽  
Β Protein ◽  
Insulinoma Cells

Death of β-cells due to apoptosis is an important contributor to β-cell dysfunction in both type 1 and type 2 diabetes mellitus. Previously, we described participation of the Group VIA Ca2+-independent phospholipase A2 (iPLA2β) in apoptosis of insulinoma cells due to ER stress. To examine whether islet β-cells are similarly susceptible to ER stress and undergo iPLA2β-mediated apoptosis, we assessed the ER stress response in human pancreatic islets. Here, we report that the iPLA2β protein is expressed predominantly in the β-cells of human islets and that thapsigargin-induced ER stress promotes β-cell apoptosis, as reflected by increases in activated caspase-3 in the β-cells. Furthermore, we demonstrate that ER stress is associated with increases in islet iPLA2β message, protein, and activity, iPLA2β-dependent induction of neutral sphingomyelinase and ceramide accumulation, and subsequent loss of mitochondrial membrane potential. We also observe that basal activated caspase-3 increases with age, raising the possibility that β-cells in older human subjects have a greater susceptibility to undergo apoptotic cell death. These findings reveal for the first time expression of iPLA2β protein in human islet β-cells and that induction of iPLA2β during ER stress contributes to human islet β-cell apoptosis. We hypothesize that modulation of iPLA2β activity might reduce β-cell apoptosis and this would be beneficial in delaying or preventing β-cell dysfunction associated with diabetes.

scholarly journals Apoptotic Killing and Phagocytosis of Host Cells by the Parasite Entamoeba histolytica

2003 ◽  
Vol 71 (2) ◽  
pp. 964-972 ◽  
Author(s):  
Christopher D. Huston ◽  
Douglas R. Boettner ◽  
Vanessa Miller-Sims ◽  
William A. Petri,
Keyword(s):  
Host Cell ◽  
Entamoeba Histolytica ◽  
Caspase 3 ◽  
Apoptotic Cell ◽  
Cell Killing ◽  
Jurkat Cells ◽  
Host Cells ◽  
Apoptotic Cells ◽  
Outer Leaflet ◽  
Phosphatidylserine Exposure

ABSTRACT The ability of Entamoeba histolytica to kill and phagocytose host cells correlates with parasite virulence. This study addressed the role of apoptotic cell killing and host cell phosphatidylserine exposure in the subsequent phagocytosis of Jurkat T cells by E. histolytica. Ingested host cells were apoptotic, as evidenced by the activation of caspase 3 in 88% ± 3% (mean and standard deviation [SD] of the mean) of Jurkat cells engulfed by E. histolytica; ingested cells without detectable active caspase 3 were already disrupted and partially digested. That apoptotic cell killing preceded phagocytosis was supported by the demonstration that a higher percentage of amebae ingested apoptotic cells than ingested healthy cells (62% ± 7% versus 30% ± 9%, respectively [mean and SD]) (P = 0.008). E. histolytica also ingested apoptotic Jurkat cells more rapidly than necrotic control cells (8.5% ± 0.4% versus 3.5% ± 0.7%, respectively [mean and SD]) (P < 0.001). The inhibition of amebic cytotoxicity with d-galactose (which blocks the amebic Gal/GalNAc lectin) blocked the phagocytosis of healthy cells by greater than 80%, providing further evidence that apoptosis preceded engulfment. In contrast, d-galactose blocked the phagocytosis of already apoptotic cells by only 40%, implicating an additional host ligand (besides d-galactose) in amebic engulfment of apoptotic cells. The most characteristic surface change on apoptotic cells is phosphatidylserine exposure. Consistent with a role for host cell phosphatidylserine exposure in amebic ingestion of killed cells, Jurkat cell phosphatidylserine was exposed during incubation with E. histolytica (27% ± 1% [mean and SD] specific increase at 30 min) (the P value versus the control was 0.0003). Approximately 50% more amebae ingested viable Jurkat cells expressing phosphatidylserine on the outer leaflet of the plasma membrane than ingested control cells (30.3% ± 2.2% versus 19.8% ± 1.9%, respectively [mean and SD]) (P = 0.003). By analogy with phagocytic clearance during apoptosis in metazoans, amebic apoptotic host cell killing followed by phagocytosis may limit inflammation and enable amebae to evade the host immune response.

scholarly journals Aquaporin-3 Attenuates Oxidative Stress-Induced Nucleus Pulposus Cell Apoptosis Through Regulating the P38 MAPK Pathway

2018 ◽  
Vol 50 (5) ◽  
pp. 1687-1697 ◽  
Author(s):  
Yichun Xu ◽  
Hui Yao ◽  
Qiyou Wang ◽  
Wenbin Xu ◽  
Kaihua Liu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Oxidative Damage ◽  
P38 Mapk ◽  
Cell Apoptosis ◽  
Caspase 3 ◽  
Mapk Pathway ◽  
Aquaporin 3 ◽  
P38 Mapk Pathway ◽  
Intracellular Ros ◽  
Cellular Apoptosis

Background/Aims: Previous studies have shown that oxidative damage is a main contributor to disc nucleus pulposus (NP) cell apoptosis. Aquaporin-3 (AQP-3) facilitates reactive oxygen species (ROS) scavenging and thus alleviates oxidative injury in other cells. This study aims to investigate the role and mechanism of AQP-3 in regulating NP cell apoptosis under oxidative damage. Methods: Rat NP cells were treated with H2O2 for 48 hours, while control NP cells were free of H2O2. Recombinant AQP-3 lentiviral vectors were used to investigate the effect of enhanced AQP-3 expression levels in NP cells. NP cell apoptosis was assessed by flow cytometry, caspase-3 activity, gene expression of apoptosis-related molecules (Bax, Bcl-2 and caspase-3), and protein expression of cellular apoptosis markers (cleaved PARP and cleaved caspase-3). Additionally, intracellular ROS content and activity of the p38 MAPK pathway were evaluated. Results: Compared with the control NP cells, oxidative damage in the treatment cells significantly increased cell apoptosis ratios and caspase-3 activity, upregulated gene expression of Bax and caspase-3, downregulated gene expression of Bcl-2, and increased protein expression of cleaved PARP and cleaved caspase-3, as well as increased intracellular ROS content and activity of the p38 MAPK pathway. However, AQP-3 overexpression partly alleviated cell apoptosis, decreased intracellular ROS content, and inhibited the p38 MAPK pathway in NP cells under oxidative damage. Conclusion: Oxidative damage can significantly downregulate AQP-3 expression. Enhancing AQP-3 expression in NP cells partly attenuates cellular apoptosis through regulating the p38 MAPK pathway under oxidative damage.

scholarly journals Ailanthone Promotes Human Vestibular Schwannoma Cell Apoptosis and Autophagy by Downregulation of miR-21

2018 ◽  
Vol 26 (6) ◽  
pp. 941-948 ◽  
Author(s):  
Peizhen Yang ◽  
Dezhong Sun ◽  
Fei Jiang
Keyword(s):  
Cell Proliferation ◽  
Cell Apoptosis ◽  
Caspase 3 ◽  
Apoptotic Cell ◽  
Ailanthus Altissima ◽  
Antitumor Activities ◽  
Caspase 9 ◽  
Chinese Medicinal Herb ◽  
Induced Apoptosis ◽  
Functional Actions

Ailanthone (AIL) is a quassinoid isolated from the traditional Chinese medicinal herb Ailanthus altissima. The antitumor activities of AIL have been reported in several cancers. The purpose of the present study was to explore the effect of AIL on vestibular schwannomas (VSs). Various concentrations of AIL (0‐1 μM) were used to treat human primary VS cells, and then cell viability, proliferation, apoptosis, and autophagy were assessed. Expression of miR-21 in VS cells was altered by miRNA transfection. The functional actions of AIL on miR-21 dysregulated cells were also assessed. AIL significantly reduced the viability of VS cells, and the IC50 value was 0.48 ± 0.023 μM. In response to 0.6 μM AIL, BrdU+ cell rate and cyclin D1 expression were reduced, apoptotic cell rate was increased, caspase 3 and caspase 9 were cleaved, Beclin-1 and LC3-II were accumulated, and p62 was downregulated. miR-21 was lowly expressed in AIL-treated cells, and AIL-induced apoptosis and autophagy were attenuated by miR-21 overexpression. In addition, AIL downregulated Ras and Raf and deactivated MEK, ERK, mTOR, and p70S6K, while the downregulation and deactivation induced by AIL were reversed by miR-21 overexpression. To conclude, AIL inhibited VS cell proliferation and induced apoptosis and autophagy. The antitumor activities of AIL in VS cells were realized possibly via downregulation of miR-21 and blocking the Ras/Raf/MEK/ERK and mTOR pathways.

scholarly journals Helicobacter pylori Outer Membrane Vesicles and Extracellular Vesicles from Helicobacter pylori-Infected Cells in Gastric Disease Development

2021 ◽  
Vol 22 (9) ◽  
pp. 4823
Author(s):  
María Fernanda González ◽  
Paula Díaz ◽  
Alejandra Sandoval-Bórquez ◽  
Daniela Herrera ◽  
Andrew F. G. Quest
Keyword(s):  
Gastric Cancer ◽  
Helicobacter Pylori ◽  
Outer Membrane ◽  
Extracellular Vesicles ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Host Cells ◽  
Gastric Epithelium ◽  
Infected Cells ◽  
H Pylori

Extracellular vesicles (EVs) are cell-derived vesicles important in intercellular communication that play an essential role in host-pathogen interactions, spreading pathogen-derived as well as host-derived molecules during infection. Pathogens can induce changes in the composition of EVs derived from the infected cells and use them to manipulate their microenvironment and, for instance, modulate innate and adaptive inflammatory immune responses, both in a stimulatory or suppressive manner. Gastric cancer is one of the leading causes of cancer-related deaths worldwide and infection with Helicobacter pylori (H. pylori) is considered the main risk factor for developing this disease, which is characterized by a strong inflammatory component. EVs released by host cells infected with H. pylori contribute significantly to inflammation, and in doing so promote the development of disease. Additionally, H. pylori liberates vesicles, called outer membrane vesicles (H. pylori-OMVs), which contribute to atrophia and cell transformation in the gastric epithelium. In this review, the participation of both EVs from cells infected with H. pylori and H. pylori-OMVs associated with the development of gastric cancer will be discussed. By deciphering which functions of these external vesicles during H. pylori infection benefit the host or the pathogen, novel treatment strategies may become available to prevent disease.

scholarly journals Lipoproteins Are Responsible for the Pro-Inflammatory Property of Staphylococcus aureus Extracellular Vesicles

2021 ◽  
Vol 22 (13) ◽  
pp. 7099
Author(s):  
Pradeep Kumar Kopparapu ◽  
Meghshree Deshmukh ◽  
Zhicheng Hu ◽  
Majd Mohammad ◽  
Marco Maugeri ◽  
...  
Keyword(s):  
Extracellular Vesicles ◽  
Inflammatory Responses ◽  
Surface Proteins ◽  
Host Cells ◽  
Immune Stimulation ◽  
Domains Of Life ◽  
Major Surface ◽  
Staphylococcal Aureus

Staphylococcal aureus (S. aureus), a Gram-positive bacteria, is known to cause various infections. Extracellular vesicles (EVs) are a heterogeneous array of membranous structures secreted by cells from all three domains of life, i.e., eukaryotes, bacteria, and archaea. Bacterial EVs are implied to be involved in both bacteria–bacteria and bacteria–host interactions during infections. It is still unclear how S. aureus EVs interact with host cells and induce inflammatory responses. In this study, EVs were isolated from S. aureus and mutant strains deficient in either prelipoprotein lipidation (Δlgt) or major surface proteins (ΔsrtAB). Their immunostimulatory capacities were assessed both in vitro and in vivo. We found that S. aureus EVs induced pro-inflammatory responses both in vitro and in vivo. However, this activity was dependent on lipidated lipoproteins (Lpp), since EVs isolated from the Δlgt showed no stimulation. On the other hand, EVs isolated from the ΔsrtAB mutant showed full immune stimulation, indicating the cell wall anchoring of surface proteins did not play a role in immune stimulation. The immune stimulation of S. aureus EVs was mediated mainly by monocytes/macrophages and was TLR2 dependent. In this study, we demonstrated that not only free Lpp but also EV-imbedded Lpp had high pro-inflammatory activity.

scholarly journals MiR-140-3p inhibits the cell viability and promotes apoptosis of synovial fibroblasts in rheumatoid arthritis through targeting sirtuin 3

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Beibei Zu ◽  
Lin Liu ◽  
Jingya Wang ◽  
Meirong Li ◽  
Junxia Yang
Keyword(s):  
Rheumatoid Arthritis ◽  
Cell Viability ◽  
Cell Apoptosis ◽  
Caspase 3 ◽  
Pearson Correlation ◽  
Fibrous Tissue ◽  
Synovial Fibroblasts ◽  
Cell Counting ◽  
Sirtuin 3 ◽  
Fibrous Tissues

Abstract Background Synovial fibroblasts (SFs) with the abnormal expressions of miRNAs are the key regulator in rheumatoid arthritis (RA). Low-expressed miR-140-3p was found in RA tissues. Therefore, we attempted to investigate the effect of miR-140-3p on SFs of RA. Methods RA and normal synovial fibrous tissue were gathered. The targets of miR-140-3p were found by bioinformatics and luciferase analysis. Correlation between the expressions of miR-140-3p with sirtuin 3 (SIRT3) was analyzed by Pearson correlation analysis. After transfection, cell viability and apoptosis were detected by cell counting kit-8 and flow cytometry. The expressions of miR-140-3p, SIRT3, Ki67, Bcl-2, Bax, and cleaved Caspase-3 were detected by RT-qPCR or western blot. Results Low expression of miR-140-3p and high expression of SIRT3 were found in RA synovial fibrous tissues. SIRT3 was a target of miR-140-3p. SIRT3 expression was negatively correlated to the expression of miR-140-3p. MiR-140-3p mimic inhibited the MH7A cell viability and the expressions of SIRT3, Ki67, and Bcl-2 and promoted the cell apoptosis and the expressions of Bax and cleaved Caspase-3; miR-140-3p inhibitor showed an opposite effect to miR-140-3p mimic on MH7A cells. SIRT3 overexpression not only promoted the cell viability and inhibited cell apoptosis of MH7A cells but also reversed the effect of miR-140-3p mimic had on MH7A cells. Conclusions The results in this study revealed that miR-140-3p could inhibit cell viability and promote apoptosis of SFs in RA through targeting SIRT3.

scholarly journals Glycosylation of Cancer Extracellular Vesicles: Capture Strategies, Functional Roles and Potential Clinical Applications

Cells ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 109
Author(s):  
Álvaro M. Martins ◽  
Cátia C. Ramos ◽  
Daniela Freitas ◽  
Celso A. Reis
Keyword(s):  
Extracellular Vesicles ◽  
Biomarker Discovery ◽  
De Novo ◽  
Recipient Cell ◽  
Cell Communication ◽  
Cancer Biomarkers ◽  
Functional Roles ◽  
Molecular Information ◽  
Glycosylation Pathway ◽  
Organ Tropism

Glycans are major constituents of extracellular vesicles (EVs). Alterations in the glycosylation pathway are a common feature of cancer cells, which gives rise to de novo or increased synthesis of particular glycans. Therefore, glycans and glycoproteins have been widely used in the clinic as both stratification and prognosis cancer biomarkers. Interestingly, several of the known tumor-associated glycans have already been identified in cancer EVs, highlighting EV glycosylation as a potential source of circulating cancer biomarkers. These particles are crucial vehicles of cell–cell communication, being able to transfer molecular information and to modulate the recipient cell behavior. The presence of particular glycoconjugates has been described to be important for EV protein sorting, uptake and organ-tropism. Furthermore, specific EV glycans or glycoproteins have been described to be able to distinguish tumor EVs from benign EVs. In this review, the application of EV glycosylation in the development of novel EV detection and capture methodologies is discussed. In addition, we highlight the potential of EV glycosylation in the clinical setting for both cancer biomarker discovery and EV therapeutic delivery strategies.

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