scholarly journals The cGMP Pathway and Inherited Photoreceptor Degeneration: Targets, Compounds, and Biomarkers

Genes ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 453 ◽  
Author(s):  
Arianna Tolone ◽  
Soumaya Belhadj ◽  
Andreas Rentsch ◽  
Frank Schwede ◽  
François Paquet-Durand
Keyword(s):  
Cell Death ◽  
Gene Mutations ◽  
Interdisciplinary Cooperation ◽  
Response To Treatment ◽  
Common Denominator ◽  
Photoreceptor Degeneration ◽  
Diverse Range ◽  
Cell Death Pathway ◽  
Cgmp Signaling ◽  
Dependent Cell

Photoreceptor physiology and pathophysiology is intricately linked to guanosine-3’,5’-cyclic monophosphate (cGMP)-signaling. Here, we discuss the importance of cGMP-signaling for the pathogenesis of hereditary retinal degeneration. Excessive accumulation of cGMP in photoreceptors is a common denominator in cell death caused by a variety of different gene mutations. The cGMP-dependent cell death pathway may be targeted for the treatment of inherited photoreceptor degeneration, using specifically designed and formulated inhibitory cGMP analogues. Moreover, cGMP-signaling and its down-stream targets may be exploited for the development of novel biomarkers that could facilitate monitoring of disease progression and reveal the response to treatment in future clinical trials. We then briefly present the importance of appropriate formulations for delivery to the retina, both for drug and biomarker applications. Finally, the review touches on important aspects of future clinical translation, highlighting the need for interdisciplinary cooperation of researchers from a diverse range of fields.

scholarly journals Programmed Non-Apoptotic Cell Death in Hereditary Retinal Degeneration: Crosstalk between cGMP-Dependent Pathways and PARthanatos?

2021 ◽  
Vol 22 (19) ◽  
pp. 10567
Author(s):  
Jie Yan ◽  
Yiyi Chen ◽  
Yu Zhu ◽  
François Paquet-Durand
Keyword(s):  
Cell Death ◽  
Retinal Degeneration ◽  
Apoptotic Cell ◽  
Gene Mutations ◽  
Therapeutic Interventions ◽  
Cellular Mechanisms ◽  
Cgmp Signaling ◽  
Dependent Cell ◽  
A Cell ◽  
Hereditary Retinal Degeneration

Programmed cell death (PCD) is a highly regulated process that results in the orderly destruction of a cell. Many different forms of PCD may be distinguished, including apoptosis, PARthanatos, and cGMP-dependent cell death. Misregulation of PCD mechanisms may be the underlying cause of neurodegenerative diseases of the retina, including hereditary retinal degeneration (RD). RD relates to a group of diseases that affect photoreceptors and that are triggered by gene mutations that are often well known nowadays. Nevertheless, the cellular mechanisms of PCD triggered by disease-causing mutations are still poorly understood, and RD is mostly still untreatable. While investigations into the neurodegenerative mechanisms of RD have focused on apoptosis in the past two decades, recent evidence suggests a predominance of non-apoptotic processes as causative mechanisms. Research into these mechanisms carries the hope that the knowledge created can eventually be used to design targeted treatments to prevent photoreceptor loss. Hence, in this review, we summarize studies on PCD in RD, including on apoptosis, PARthanatos, and cGMP-dependent cell death. Then, we focus on a possible interplay between these mechanisms, covering cGMP-signaling targets, overactivation of poly(ADP-ribose)polymerase (PARP), energy depletion, Ca2+-permeable channels, and Ca2+-dependent proteases. Finally, an outlook is given into how specific features of cGMP-signaling and PARthanatos may be targeted by therapeutic interventions.

scholarly journals Asc Modulates the Function of NLRC4 in Response to Infection of Macrophages by Legionella pneumophila

mBio ◽  
2011 ◽  
Vol 2 (4) ◽  
Author(s):  
Christopher L. Case ◽  
Craig R. Roy
Keyword(s):  
Cell Death ◽  
Legionella Pneumophila ◽  
Fluorescent Protein ◽  
Microbial Infection ◽  
Content Type ◽  
Caspase 1 ◽  
Cell Death Pathway ◽  
Dependent Cell ◽  
Green Fluorescent ◽  
In Cells

ABSTRACTNucleotide-binding domain, leucine-rich repeat containing proteins (NLRs) activate caspase-1 in response to a variety of bacterium-derived signals in macrophages. NLR-mediated activation of caspase-1 byLegionella pneumophilaoccurs through both an NLRC4/NAIP5-dependent pathway and a pathway requiring the adapter protein Asc. Both pathways are needed for maximal activation of caspase-1 and for the release of the cytokines interleukin-1β (IL-1β) and IL-18. Asc is not required for caspase-1-dependent pore formation and cell death induced upon infection of macrophages byL. pneumophila. Here, temporal and spatial localization of caspase-1-dependent processes was examined to better define the roles of Asc and NLRC4 during infection. Imaging studies revealed that caspase-1 localized to a single punctate structure in infected cells containing Asc but not in cells lacking this adapter. Both endogenous Asc and ectopically produced NLRC4 tagged with green fluorescent protein (GFP) were found to localize to caspase-1 puncta followingL. pneumophilainfection, suggesting that NLRC4 and Asc coordinate signaling through this complex during caspase-1 activation. Formation of caspase-1-containing puncta correlated with caspase-1 processing, suggesting a role for the Asc/NLRC4/caspase-1 complex in caspase-1 cleavage. In cells deficient for Asc, NLRC4 did not assemble into discrete puncta, and pyroptosis occurred at an accelerated rate. These data indicate that Asc mediates integration of NLR components into caspase-1 processing platforms and that recruitment of NLR components into an Asc complex can dampen pyroptotic responses. Thus, a negative feedback role of complexes containing Asc may be important for regulating caspase-1-mediated responses during microbial infection.IMPORTANCECaspase-1 is a protease activated during infection that is central to the regulation of several innate immune pathways. Studies examining the macromolecular complexes containing this protein, known as inflammasomes, have provided insight into the regulation of this protease. This work demonstrates that the intracellular bacteriumLegionella pneumophilainduces formation of complexes containing caspase-1 by multiple mechanisms and illustrates that an adapter molecule called Asc integrates signals from multiple independent upstream caspase-1 activators in order to assemble a spatially distinct complex in the macrophage. There were caspase-1-associated activities such as cytokine processing and secretion that were controlled by Asc. Importantly, this work uncovered a new role for Asc in dampening a caspase-1-dependent cell death pathway called pyroptosis. These findings suggest that Asc plays a central role in controlling a distinct subset of caspase-1-dependent activities by both assembling complexes that are important for cytokine processing and suppressing processes that mediate pyroptosis.

scholarly journals Eagle Effect in Nonreplicating Persister Mycobacteria

2015 ◽  
Vol 59 (12) ◽  
pp. 7786-7789 ◽  
Author(s):  
Mu-Lu Wu ◽  
Jasmie Tan ◽  
Thomas Dick
Keyword(s):  
Cell Death ◽  
Protein Synthesis ◽  
Dose Response ◽  
Mycobacterium Smegmatis ◽  
Content Type ◽  
Cell Death Pathway ◽  
Low Concentrations ◽  
Eagle Effect ◽  
Dependent Cell ◽  
Gyrase Inhibitors

ABSTRACTWe determined the microbicidal activities of antibacterials against nonreplicatingMycobacterium smegmatisgrown in a starvation-based Loebel model for persistence. Whereas most drugs lost their activity, fluoroquinolones retained lethal potency. Dose-response characterizations showed a paradoxical more-drug-kills-less Eagle effect. Pretreatment of cultures with chloramphenicol blocked the lethal action of the gyrase inhibitors. These results suggest that fluoroquinolones at low concentrations trigger a protein synthesis-dependent cell death pathway and shut off this suicide pathway at elevated concentrations.

scholarly journals Ferroptosis in plants: triggers, proposed mechanisms, and the role of iron in modulating cell death

2020 ◽  
Author(s):  
Ayelén Mariana Distéfano ◽  
Gabriel Alejandro López ◽  
Nicolás Setzes ◽  
Fernanda Marchetti ◽  
Maximiliano Cainzos ◽  
...  
Keyword(s):  
Cell Death ◽  
Metabolic Pathways ◽  
Oxygen Species ◽  
Cell Death Pathway ◽  
Plant Life ◽  
Regulated Cell Death ◽  
Dependent Cell ◽  
Plant Life Cycle ◽  
High Degree

Abstract Regulated cell death plays key roles during essential processes throughout the plant life cycle. It takes part in specific developmental programs and maintains homeostasis of the organism in response to unfavorable environments. Ferroptosis is a recently discovered iron-dependent cell death pathway characterized by the accumulation of lipid reactive oxygen species. In plants, ferroptosis shares all the main hallmarks described in other systems. Those specific features include biochemical and morphological signatures that seem to be conserved among species. However, plant cells have specific metabolic pathways and a high degree of metabolic compartmentalization. Together with their particular morphology, these features add more complexity to the plant ferroptosis pathway. In this review, we summarize the most recent advances in elucidating the roles of ferroptosis in plants, focusing on specific triggers, the main players, and underlying pathways.

Caspase-cleaved HPK1 induces CD95L-independent activation-induced cell death in T and B lymphocytes

Blood ◽  
2007 ◽  
Vol 110 (12) ◽  
pp. 3968-3977 ◽  
Author(s):  
Dirk Brenner ◽  
Alexander Golks ◽  
Mareike Becker ◽  
Wolfgang Müller ◽  
Christian R. Frey ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Death ◽  
Cell Fate ◽  
B Lymphocytes ◽  
T And B Lymphocytes ◽  
Cell Death Pathways ◽  
Activation Induced Cell Death ◽  
Cell Death Pathway ◽  
Dependent Cell ◽  
Interfering Rna

Abstract Life and death of peripheral lymphocytes is strictly controlled to maintain physiologic levels of T and B cells. Activation-induced cell death (AICD) is one mechanism to delete superfluous lymphocytes by restimulation of their immunoreceptors and it depends partially on the CD95/CD95L system. Recently, we have shown that hematopoietic progenitor kinase 1 (HPK1) determines T-cell fate. While full-length HPK1 is essential for NF-κB activation in T cells, the C-terminal fragment of HPK1, HPK1-C, suppresses NF-κB and sensitizes toward AICD by a yet undefined cell death pathway. Here we show that upon IL-2–driven expansion of primary T cells, HPK1 is converted to HPK1-C by a caspase-3 activity below the threshold of apoptosis induction. HPK1-C se-lectively blocks induction of NF-κB–dependent antiapoptotic Bcl-2 family members but not of the proapoptotic Bcl-2 family member Bim. Interestingly, T and B lymphocytes from HPK1-C transgenic mice undergo AICD independently of the CD95/CD95L system but involving caspase-9. Knock down of HPK1/HPK1-C or Bim by small interfering RNA shows that CD95L-dependent and HPK1/HPK1-C–dependent cell death pathways complement each other in AICD of primary T cells. Our results define HPK1-C as a suppressor of antiapoptotic Bcl-2 proteins and provide a molecular basis for our understanding of CD95L-independent AICD of lymphocytes.

scholarly journals Role of CNC1 gene in TDP-43 aggregation-induced oxidative stress-mediated cell death in S. cerevisiae model of ALS

2020 ◽  
Author(s):  
Vidhya Bharathi ◽  
Amandeep Girdhar ◽  
Basant K Patel
Keyword(s):  
Oxidative Stress ◽  
Cell Death ◽  
Stress Response ◽  
Molecular Mechanisms ◽  
Motor Neuron Diseases ◽  
C Protein ◽  
Cell Death Pathway ◽  
Cyclin C ◽  
Dependent Cell ◽  
Anti Oxidant

ABSTRACTTDP-43 is a multi-functional ribonucleoprotein that is also found deposited as hyper-phosphorylated and ubiquitinated TDP-43 inclusions in the brain and spinal cord of the patients of the motor neuron diseases, amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). Till date, how the cell death ensues is not fully deciphered although several molecular mechanisms of the TDP-43 toxicity such as impairments of endocytosis and chromatin remodelling, mis-regulations of autophagy and proteasome function, mis-localization to the mitochondria and generation of oxidative stress etc., have been proposed. A predominantly nuclear protein, Cyclin C, can regulate the oxidative stress response by affecting the transcription of stress response genes and also by translocation to the cytoplasm for the activation of the mitochondrial fragmentation-dependent cell death pathway. Using the well-established yeast model of TDP-43 aggregation and toxicity, we examined here whether upon TDP-43 aggregation, the cell survival depends on the presence of the CNC1 gene that encodes Cyclin C protein or other genes that encode proteins that function in conjunction with Cyclin C, such as the DNM1, FIS1 and MED13 genes. We found that the TDP-43 toxicity is significantly reduced in the yeast deleted for the CNC1 or DNM1 genes. Importantly, the rescue of TDP-43 toxicity in these yeast deletion backgrounds required the presence of functional mitochondria. Also, the deletion of YBH3 gene, which encodes for a protein involved in the mitochondria-dependent apoptosis, also reduced the TDP-43 toxicity. Furthermore, Cyclin C-YFP was observed to localize from the nucleus to the cytoplasm in response to the TDP-43 co-expression. Also, this cytoplasmic localization of Cyclin C was prevented by the addition of an anti-oxidant molecule, N-acetyl-cysteine. Taken together, our data suggest that Cyclin C, Dnm1 and Ybh3 proteins are important in mediating the TDP-43-induced oxidative stress-mediated cell death in the S. cerevisiae model.

scholarly journals AEBP1 down regulation induced cell death pathway depends on PTEN status of glioma cells

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Swati Sinha ◽  
Arun Renganathan ◽  
Prathima B. Nagendra ◽  
Vasudeva Bhat ◽  
Brian Steve Mathew ◽  
...  
Keyword(s):  
Dna Damage ◽  
Cell Death ◽  
Cellular Proliferation ◽  
Ectopic Expression ◽  
Glioma Cells ◽  
Down Regulation ◽  
Over Expression ◽  
Cell Death Pathway ◽  
Dependent Cell ◽  
Parp 1

Abstract Glioblastoma (GBM) is the most common aggressive form of brain cancer with overall dismal prognosis (10–12 months) despite all current multimodal treatments. Previously we identified adipocyte enhancer binding protein 1 (AEBP1) as a differentially regulated gene in GBM. On probing the role of AEBP1 over expression in glioblastoma, we found that both cellular proliferation and survival were affected upon AEBP1 silencing in glioma cells, resulting in cell death. In the present study we report that the classical caspase pathway components are not activated in cell death induced by AEBP1 down regulation in PTEN-deficient (U87MG and U138MG) cells. PARP-1 was not cleaved but over-activated under AEBP1 down regulation which leads to the synthesis of PAR in the nucleus triggering the release of AIF from the mitochondria. Subsequently, AIF translocates to the nucleus along with MIF causing chromatinolysis. AEBP1 positively regulates PI3KinaseCβ by the binding to AE-1 binding element in the PI3KinaseCβ promoter. Loss of PI3KinaseCβ expression under AEBP1 depleted condition leads to excessive DNA damage and activation of PARP-1. Furthermore, over expression of PIK3CB (in trans) in U138MG cells prevents DNA damage in these AEBP1 depleted cells. On the contrary, AEBP1 down regulation induces caspase-dependent cell death in PTEN-proficient (LN18 and LN229) cells. Ectopic expression of wild-type PTEN in PTEN-deficient U138MG cells results in the activation of canonical caspase and Akt dependent cell death. Collectively, our findings define AEBP1 as a potential oncogenic driver in glioma, with potential implications for therapeutic intervention.

scholarly journals Mitochondrial Entry of Cytotoxic Proteases: A New Insight into the Granzyme B Cell Death Pathway

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Denis Martinvalet
Keyword(s):  
Cell Death ◽  
B Cell ◽  
Granzyme B ◽  
Mitochondrial Outer Membrane ◽  
Dependent Manner ◽  
Mitochondrial Outer Membrane Permeabilization ◽  
Cell Death Pathway ◽  
Dependent Cell ◽  
Mitochondrial Death Pathway ◽  
Insight Into

The mitochondria represent an integration and amplification hub for various death pathways including that mediated by granzyme B (GB), a granule enzyme expressed by cytotoxic lymphocytes. GB activates the proapoptotic B cell CLL/lymphoma 2 (Bcl-2) family member BH3-interacting domain death agonist (BID) to switch on the intrinsic mitochondrial death pathway, leading to Bcl-2-associated X protein (Bax)/Bcl-2 homologous antagonist/killer- (Bak-) dependent mitochondrial outer membrane permeabilization (MOMP), the dissipation of mitochondrial transmembrane potential (ΔΨm), and the production of reactive oxygen species (ROS). GB can also induce mitochondrial damage in the absence of BID, Bax, and Bak, critical for MOMP, indicating that GB targets the mitochondria in other ways. Interestingly, granzyme A (GA), GB, and caspase 3 can all directly target the mitochondrial respiratory chain complex I for ROS-dependent cell death. Studies of ROS biogenesis have revealed that GB must enter the mitochondria for ROS production, making the mitochondrial entry of cytotoxic proteases (MECP) an unexpected critical step in the granzyme death pathway. MECP requires an intact ΔΨm and is mediated though Sam50 and Tim22 channels in a mtHSP70-dependent manner. Preventing MECP severely compromises GB cytotoxicity. In this review, we provide a brief overview of the canonical mitochondrial death pathway in order to put into perspective this new insight into the GB action on the mitochondria to trigger ROS-dependent cell death.

Follicular expression of a human β-cell leukaemia/lymphoma-2 (Bcl-2) transgene does not decrease atresia or increase ovulation rate in swine

2005 ◽  
Vol 17 (4) ◽  
pp. 457 ◽  
Author(s):  
H. D. Guthrie ◽  
R. J. Wall ◽  
V. G. Pursel ◽  
J. A. Foster-Frey ◽  
D. M. Donovan ◽  
...  
Keyword(s):  
Cell Death ◽  
Ectopic Expression ◽  
Immunohistochemical Analysis ◽  
Polymerase Chain Reaction Analysis ◽  
Ovulation Rate ◽  
Cell Leukaemia ◽  
Α Subunit ◽  
Cell Death Pathways ◽  
Cell Death Pathway ◽  
Dependent Cell

Transgenic (TG) gilts carrying a human Bcl-2 cDNA transgene driven by mouse inhibin-α subunit promoter were produced and evaluated to determine if ectopic expression of Bcl-2 in the ovaries would decrease the frequency of atresia in antral follicles and increase ovulation rate. Immunohistochemical analysis showed that the Bcl-2 transgene protein was expressed in granulosa and theca cells, in 86% of healthy and 54% of atretic follicles analysed in TG prepubertal and Day 50 pregnant gilts combined (n = 24). In contrast, Bcl-2 transgene protein was expressed in only 1.4% of healthy and 0% of atretic follicles in non-TG littermates (n = 13). Real-time reverse transcription–polymerase chain reaction analysis confirmed that human Bcl-2 was expressed in follicles of TG gilts. The atresia rate for the TG and non-TG groups did not differ (P > 0.05) for prepubertal (45 v. 59%) and Day 50 pregnant gilts (53 v. 52%) respectively. The mean ± s.e.m. ovulation rate did not differ (P > 0.5) between TG (15.9 ± 0.8, n = 12) and non-TG (16.4 ± 0.6, n = 7) Day 50 pregnant gilts. The molecular basis of the failure of ectopic Bcl-2 expression to increase the ratio of healthy to atretic follicles is unknown, but it is possible that the activity of the mitochondrial-dependent cell death pathway was not neutralized by ectopic expression of human Bcl-2 or that other cell death pathways compensated for the decreased mitochondrial-dependent cell death.

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