scholarly journals Viral-Induced Systemic Necrosis in Plants Involves Both Programmed Cell Death and the Inhibition of Viral Multiplication, Which Are Regulated by Independent Pathways

2010 ◽  
Vol 23 (3) ◽  
pp. 283-293 ◽  
Author(s):  
Ken Komatsu ◽  
Masayoshi Hashimoto ◽  
Johji Ozeki ◽  
Yasuyuki Yamaji ◽  
Kensaku Maejima ◽  
...  
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Viral Infection ◽  
Expression Patterns ◽  
Plant Viruses ◽  
Virus Multiplication ◽  
Mitogen Activated Protein Kinase ◽  
Systemic Necrosis ◽  
Viral Multiplication ◽  
Plantago Asiatica

Resistant plants respond rapidly to invading avirulent plant viruses by triggering a hypersensitive response (HR). An HR is accompanied by a restraint of virus multiplication and programmed cell death (PCD), both of which have been observed in systemic necrosis triggered by a successful viral infection. Here, we analyzed signaling pathways underlying the HR in resistance genotype plants and those leading to systemic necrosis. We show that systemic necrosis in Nicotiana benthamiana, induced by Plantago asiatica mosaic virus (PlAMV) infection, was associated with PCD, biochemical features, and gene expression patterns that are characteristic of HR. The induction of necrosis caused by PlAMV infection was dependent on SGT1, RAR1, and the downstream mitogen-activated protein kinase (MAPK) cascade involving MAPKKKα and MEK2. However, although SGT1 and RAR1 silencing led to an increased accumulation of PlAMV, silencing of the MAPKKKα-MEK2 cascade did not. This observation indicates that viral multiplication is partly restrained even in systemic necrosis induced by viral infection, and that this restraint requires SGT1 and RAR1 but not the MAPKKKα-MEK2 cascade. Similarly, although both SGT1 and MAPKKKα were essential for the Rx-mediated HR to Potato virus X (PVX), SGT1 but not MAPKKKα was involved in the restraint of PVX multiplication. These results suggest that systemic necrosis and HR consist of PCD and a restraint of virus multiplication, and that the latter is induced through unknown pathways independent from the former.

scholarly journals Cell Death Triggered by a Putative Amphipathic Helix of Radish mosaic virus Helicase Protein Is Tightly Correlated With Host Membrane Modification

2015 ◽  
Vol 28 (6) ◽  
pp. 675-688 ◽  
Author(s):  
Masayoshi Hashimoto ◽  
Ken Komatsu ◽  
Ryo Iwai ◽  
Takuya Keima ◽  
Kensaku Maejima ◽  
...  
Keyword(s):  
Cell Death ◽  
Mosaic Virus ◽  
Defense Responses ◽  
Plant Viruses ◽  
Amphipathic Helix ◽  
Membrane Structures ◽  
Membrane Modification ◽  
Systemic Necrosis ◽  
Amino Terminal ◽  
Er Membrane

Systemic necrosis is one of the most severe symptoms caused by plant RNA viruses. Recently, systemic necrosis has been suggested to have similar features to a defense response referred to as the hypersensitive response (HR), a form of programmed cell death. In virus-infected plant cells, host intracellular membrane structures are changed dramatically for more efficient viral replication. However, little is known about whether this replication-associated membrane modification is the cause of the symptoms. In this study, we identified an amino-terminal amphipathic helix of the helicase encoded by Radish mosaic virus (RaMV) (genus Comovirus) as an elicitor of cell death in RaMV-infected plants. Cell death caused by the amphipathic helix had features similar to HR, such as SGT1-dependence. Mutational analyses and inhibitor assays using cerulenin demonstrated that the amphipathic helix–induced cell death was tightly correlated with dramatic alterations in endoplasmic reticulum (ER) membrane structures. Furthermore, the cell death–inducing activity of the amphipathic helix was conserved in Cowpea mosaic virus (genus Comovirus) and Tobacco ringspot virus (genus Nepovirus), both of which are classified in the family Secoviridae. Together, these results indicate that ER membrane modification associated with viral intracellular replication may be recognized to prime defense responses against plant viruses.

scholarly journals Molecular basis of disregulation of programmed lymphocytes’ death in chronic viral infection

2006 ◽  
Vol 5 (2) ◽  
pp. 23-34
Author(s):  
V. V. Novitsky ◽  
N. V. Ryazantseva ◽  
O. B. Zhoukova
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Viral Infection ◽  
Immune Cells ◽  
Molecular Basis ◽  
Molecular Mechanisms ◽  
Recent Literature ◽  
Chronic Viral Infection ◽  
Persistent Viruses

The review analyses information from recent literature and results of the authors’ own investigations concerning imbalance of programmed cell death in forming chronic viral infection. Molecular mechanisms of apoptosis modulation of immune cells by persistent viruses are discussed in the article.

scholarly journals Ca2+-dependent nuclease is involved in DNA degradation during the formation of the secretory cavity by programmed cell death in fruit of Citrus grandis ‘Tomentosa’

2020 ◽  
Vol 71 (16) ◽  
pp. 4812-4827 ◽  
Author(s):  
Mei Bai ◽  
Minjian Liang ◽  
Bin Huai ◽  
Han Gao ◽  
Panpan Tong ◽  
...  
Keyword(s):  
Cell Death ◽  
In Situ Hybridization ◽  
Programmed Cell Death ◽  
Nuclear Dna ◽  
Expression Patterns ◽  
Citrus Fruit ◽  
Dna Degradation ◽  
Secretory Cavity ◽  
Spatio Temporal

Abstract The secretory cavity is a typical structure in Citrus fruit and is formed by schizolysigeny. Previous reports have indicated that programmed cell death (PCD) is involved in the degradation of secretory cavity cells in the fruit, and that the spatio-temporal location of calcium is closely related to nuclear DNA degradation in this process; however, the molecular mechanisms underlying this Ca2+ regulation remain largely unknown. Here, we identified CgCaN that encodes a Ca2+-dependent DNase in the fruit of Citrus grandis ‘Tomentosa’, the function of which was studied using calcium ion localization, DNase activity assays, in situ hybridization, and protein immunolocalization. The results suggested that the full-length cDNA of CgCaN contains an ORF of 1011 bp that encodes a protein 336 amino acids in length with a SNase-like functional domain. CgCaN digests dsDNA at neutral pH in a Ca2+-dependent manner. In situ hybridization signals of CgCaN were particularly distributed in the secretory cavity cells. Ca2+ and Ca2+-dependent DNases were mainly observed in the condensed chromatin and in the nucleolus. In addition, spatio-temporal expression patterns of CgCaN and its protein coincided with the time-points that corresponded to chromatin degradation and nuclear rupture during the PCD in the development of the fruit secretory cavity. Taken together, our results suggest that Ca2+-dependent DNases play direct roles in nuclear DNA degradation during the PCD of secretory cavity cells during Citrus fruit development. Given the consistency of the expression patterns of genes regulated by calmodulin (CaM) and calcium-dependent protein kinases (CDPK) and the dynamics of calcium accumulation, we speculate that CaM and CDPK proteins might be involved in Ca2+ transport from the extracellular walls through the cytoplasm and into the nucleus to activate CgCaN for DNA degradation.

Genetic Loci Controlling Lethal Cell Death in Tomato Caused by Viral Satellite RNA Infection

2012 ◽  
Vol 25 (8) ◽  
pp. 1034-1044 ◽  
Author(s):  
Ping Xu ◽  
Hua Wang ◽  
Frank Coker ◽  
Jun-ying Ma ◽  
Yuhong Tang ◽  
...  
Keyword(s):  
Cell Death ◽  
In Situ Hybridization ◽  
Programmed Cell Death ◽  
Minus Strand ◽  
Satellite Rna ◽  
Dominant Trait ◽  
Systemic Necrosis ◽  
Backcross Population ◽  
Major Qtl

Cucumber mosaic virus (CMV) associated with D satellite RNA (satRNA) causes lethal systemic necrosis (LSN) in tomato (Solanum lycopersicum), which involves programmed cell death. No resistance to this disease has been found in tomato. We obtained a line of wild tomato, S. habrochaitis, with a homogeneous non-lethal response (NLR) to the infection. This line of S. habrochaitis was crossed with tomato to generate F1 plants that survived the infection with NLR, indicating that NLR is a dominant trait. The NLR trait was successfully passed on to the next generation. The phenotype and genotype segregation was analyzed in the first backcross population. The analyses indicate that the NLR trait is determined by quantitative trait loci (QTL). Major QTL associated with the NLR trait were mapped to chromosomes 5 and 12. Results from Northern blot and in situ hybridization analyses revealed that the F1 and S. habrochaitis plants accumulated minus-strand satRNA more slowly than tomato, and fewer vascular cells were infected. In addition, D satRNA-induced LSN in tomato is correlated with higher accumulation of the minus-strand satRNA compared with the accumulation of the minus strand of a non-necrogenic mutant D satRNA.

scholarly journals Identification of Novel Potential Genes Involved in Cancer by Integrated Comparative Analyses

2020 ◽  
Vol 21 (24) ◽  
pp. 9560
Author(s):  
Francesco Monticolo ◽  
Emanuela Palomba ◽  
Maria Luisa Chiusano
Keyword(s):  
Gene Expression ◽  
Cell Death ◽  
Programmed Cell Death ◽  
Homo Sapiens ◽  
Expression Patterns ◽  
Comparative Approach ◽  
Expression Data ◽  
New Genes ◽  
Conserved Genes ◽  
Multiple Species

The main hallmarks of cancer diseases are the evasion of programmed cell death, uncontrolled cell division, and the ability to invade adjacent tissues. The explosion of omics technologies offers challenging opportunities to identify molecular agents and processes that may play relevant roles in cancer. They can support comparative investigations, in one or multiple experiments, exploiting evidence from one or multiple species. Here, we analyzed gene expression data from induction of programmed cell death and stress response in Homo sapiens and compared the results with Saccharomyces cerevisiae gene expression during the response to cell death. The aim was to identify conserved candidate genes associated with Homo sapiens cell death, favored by crosslinks based on orthology relationships between the two species. We identified differentially-expressed genes, pathways that are significantly dysregulated across treatments, and characterized genes among those involved in induced cell death. We investigated on co-expression patterns and identified novel genes that were not expected to be associated with death pathways, that have a conserved pattern of expression between the two species. Finally, we analyzed the resulting list by HumanNet and identified new genes predicted to be involved in cancer. The data integration and the comparative approach between distantly-related reference species that were here exploited pave the way to novel discoveries in cancer therapy and also contribute to detect conserved genes potentially involved in programmed cell death.

scholarly journals Immunophenotypes Based on the Tumor Immune Microenvironment Allow for Unsupervised Penile Cancer Patient Stratification

Cancers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1796 ◽  
Author(s):  
Chengbiao Chu ◽  
Kai Yao ◽  
Jiangli Lu ◽  
Yijun Zhang ◽  
Keming Chen ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Death ◽  
Programmed Cell Death ◽  
Cytotoxic T Lymphocyte ◽  
Granzyme B ◽  
Expression Patterns ◽  
Tumor Infiltrating Lymphocytes ◽  
Immune Checkpoints ◽  
Immune Microenvironment ◽  
Tumor Immune Microenvironment

The tumor immune microenvironment (TIME) plays an important role in penile squamous cell carcinoma (peSCC) pathogenesis. Here, the immunophenotype of the TIME in peSCC was determined by integrating the expression patterns of immune checkpoints (programmed cell death-1 (PD-1)/programmed cell death ligand-1 (PD-L1), cytotoxic T lymphocyte antigen 4 (CTLA-4), and Siglec-15) and the components of tumor-infiltrating lymphocytes, including CD8+ or Granzyme B+ T cells, FOXP3+ regulatory T cells, and CD68+ or CD206+ macrophages, in 178 patients. A high density of Granzyme B, FOXP3, CD68, CD206, PD-1, and CTLA-4 was associated with better disease-specific survival (DSS). The patients with diffuse PD-L1 tumor cell expression had worse prognoses than those with marginal or negative PD-L1 expression. Four immunophenotypes were identified by unsupervised clustering analysis, based on certain immune markers, which were associated with DSS and lymph node metastasis (LNM) in peSCC. There was no significant relationship between the immunophenotypes and high-risk human papillomavirus (hrHPV) infection. However, the hrHPV–positive peSCC exhibited a higher density of stromal Granzyme B and intratumoral PD-1 than the hrHPV–negative tumors (p = 0.049 and 0.002, respectively). In conclusion, the immunophenotypes of peSCC were of great value in predicting LNM and prognosis, and may provide support for clinical stratification management and immunotherapy intervention.

scholarly journals Expression of a Toxoneuron nigriceps polydnavirus-encoded protein causes apoptosis-like programmed cell death in lepidopteran insect cells

2005 ◽  
Vol 86 (4) ◽  
pp. 963-971 ◽  
Author(s):  
Renée Lapointe ◽  
Rebecca Wilson ◽  
Lluïsa Vilaplana ◽  
David R. O'Reilly ◽  
Patrizia Falabella ◽  
...  
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Recombinant Virus ◽  
Insect Cells ◽  
Expression Patterns ◽  
Parental Virus ◽  
Tunel Staining ◽  
Lepidopteran Insect ◽  
High Five Cells ◽  
Toxoneuron Nigriceps

The polydnavirus Toxoneuron nigriceps bracovirus (TnBV) is an obligate symbiont associated with the braconid wasp T. nigriceps, a parasitoid of Heliothis virescens larvae. Previously, to identify polydnavirus genes that allow parasitization by altering the host immune and endocrine systems, expression patterns of TnBV genes from parasitized H. virescens larvae were analysed and cDNAs were obtained. To study the function of the protein from one such cDNA, TnBV1, overexpression of the protein was attempted by using the baculovirus Autographa californica multicapsid nucleopolyhedrovirus. Recovery of stable recombinant virus was unsuccessful, with the exception of recombinants with deletions/mutations within the TnBV1 gene. It was hypothesized that TnBV1 expression was cytotoxic to the Spodoptera frugiperda (Sf21) insect cells that were used to produce the recombinants. Therefore, the Bac-to-Bac system was used to create recombinant baculoviruses maintained in Escherichia coli expressing either TnBV1 (Ac-TnBV1) or an initiator-methionine mutant [Ac-TnBV1(ATG−)]. Microscopy revealed substantial cell death of Sf21 and High Five cells from 48 h post-infection with Ac-TnBV1, but not with the Ac-TnBV1(ATG−) recombinant virus. Ac-TnBV1-infected Sf21 cells, but not those with parental virus infection, showed an increased caspase-3-like protease activity, as well as increased terminal deoxynucleotidyltransferase-mediated dUTP nick-end labelling (TUNEL) for breaks in host genomic DNA. Although indicative of apoptosis, blebbing and apoptotic bodies were not observed in infected cells. Transiently expressing TnBV1 alone caused TUNEL staining in High Five cells. These data suggest that TnBV1 expression alone can induce apoptosis-like programmed cell death in two insect cell lines. Injection of Ac-TnBV1 budded virus, compared with parental virus, did not result in an alteration of virulence in H. virescens larvae.

Sign in / Sign up

Export Citation Format

Share Document