scholarly journals Role of Gasdermins in the Biogenesis of Apoptotic Cell–Derived Exosomes

2021 ◽  
Author(s):  
Jaehark Hur ◽  
Yeon Ji Kim ◽  
Da Ae Choi ◽  
Dae Wook Kang ◽  
Jaeyoung Kim ◽  
...  
Keyword(s):  
Inflammatory Responses ◽  
Apoptotic Cell ◽  
Living Cells ◽  
Multivesicular Bodies ◽  
The Novel ◽  
Domain Family ◽  
Pore Forming Proteins ◽  
Dying Cells

Abstract The gasdermins are a family of pore-forming proteins that has recently been suggested to play a central role in the pyroptosis and the release of inflammatory cytokines. Here, we describe the novel roles of gasdermins in the biogenesis of apoptotic cell–derived exosomes. In apoptotic cells, GADMA, GSDMC, GSDMD, and GSDME increased the release of ApoExos, and both their full-length and cleaved forms were localized in the exosomal membrane. GSDMB and DFNB59, on the other hand, negatively affected the release of ApoExos. The caspase-mediated cleavage of gasdermins, especially GSDME, is suggested to increase Ca2+ influx to cytosol through endosomal pores and thus increase the biogenesis of ApoExos. In addition, the GSDME-mediated biogenesis of ApoExos depended on the ESCRT-III complex and endosomal recruitment of Ca2+-dependent proteins: annexins A2 and A7, the PEF domain family proteins sorcin and grancalcin, and the Bro1 domain protein HD-PTP. Therefore, we propose that the biogenesis of ApoExos begins when gasdermin-mediated endosomal pores increase cytosolic Ca2+, continues through the recruitment of annexin-sorcin/grancalcin-HD-PTP, and is completed when the ESCRT-III complex synthesizes intraluminal vesicles in the multivesicular bodies of dying cells. Finally, we found that GSDME-bearing tumors released ApoExos to induce inflammatory responses in the in vivo 4T1 orthotropic model of breast cancer. The data presented in this study indicate that the switch from apoptosis to pyroptosis could drive the transfer of mass signals to nearby or distant living cells and tissues by way of extracellular vesicles, and that gasdermins play critical roles in that process.

scholarly journals Role of Gasdermins in the Biogenesis of Apoptotic Cell–Derived Exosomes

2021 ◽  
Author(s):  
Jaehark Hur ◽  
Yeon Ji Kim ◽  
Da Ae Choi ◽  
Dae Wook Kang ◽  
Jaeyoung Kim ◽  
...  
Keyword(s):  
Inflammatory Responses ◽  
Apoptotic Cell ◽  
Multivesicular Bodies ◽  
The Novel ◽  
Domain Family ◽  
Flow Through ◽  
Pore Forming Proteins ◽  
Dying Cells

AbstractThe gasdermins, GSDMA, GSDMB, GSDMC, GSDMD, DFNA5, and DFNB59, are a family of pore-forming proteins that has recently been suggested to play a central role in the pyroptosis and the release of inflammatory cytokines. Here, we describe the novel roles of gasdermins in the biogenesis of apoptotic cell–derived exosomes. In apoptotic cells, GADMA, GSDMC, GSDMD, and DFNA5 increased the release of ApoExos, and both their full-length and cleaved forms were localized in the exosomal membrane. GSDMB and DFNB59, on the other hand, negatively affected the release of ApoExos. The caspase-mediated cleavage of gasdermins, especially DFNA5, is suggested to enable cytosolic Ca2+ to flow through endosomal pores and thus increase the biogenesis of ApoExos. In addition, the DFNA5-meidiated biogenesis of ApoExos depended on the ESCRT-III complex and endosomal recruitment of Ca2+-dependent proteins: annexins A2 and A7, the PEF domain family proteins sorcin and grancalcin, and the Bro1 domain protein HD-PTP. Therefore, we propose that the biogenesis of ApoExos begins when gasdermin-mediated endosomal pores increase cytosolic Ca2+, continues through the recruitment of annexin-sorcin/grancalcin-HD-PTP, and is completed when the ESCRT-III complex synthesizes intraluminal vesicles in the multivesicular bodies of dying cells. Finally, we found that Dfna5-bearing tumors released ApoExos to induce inflammatory responses in the in vivo 4T1 orthotropic model of breast cancer. The data presented in this study indicate that the switch from apoptosis to pyroptosis could drive the transfer of mass signals to nearby or distant living cells and tissues by way of extracellular vesicles, and that gasdermins play critical roles in that process.

scholarly journals Involvement of HECTD1 in LPS-induced astrocyte activation via σ-1R-JNK/p38-FOXJ2 axis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ying Tang ◽  
Mengchun Zhou ◽  
Rongrong Huang ◽  
Ling Shen ◽  
Li Yang ◽  
...  
Keyword(s):  
Inflammatory Responses ◽  
Astrocyte Activation ◽  
Hect Domain ◽  
P38 Inhibitor ◽  
Ubiquitin Protein Ligase ◽  
Primary Mouse ◽  
Lps Treatment

Abstract Background Astrocytes participate in innate inflammatory responses within the mammalian central nervous system (CNS). HECT domain E3 ubiquitin protein ligase 1 (HECTD1) functions during microglial activation, suggesting a connection with neuroinflammation. However, the potential role of HECTD1 in astrocytes remains largely unknown. Results Here, we demonstrated that HECTD1 was upregulated in primary mouse astrocytes after 100 ng/ml lipopolysaccharide (LPS) treatment. Genetic knockdown of HECTD1 in vitro or astrocyte-specific knockdown of HECTD1 in vivo suppressed LPS-induced astrocyte activation, whereas overexpression of HECTD1 in vitro facilitated LPS-induced astrocyte activation. Mechanistically, we established that LPS activated σ-1R-JNK/p38 pathway, and σ-1R antagonist BD1047, JNK inhibitor SP600125, or p38 inhibitor SB203580 reversed LPS-induced expression of HECTD1, thus restored LPS-induced astrocyte activation. In addition, FOXJ2 functioned as a transcription factor of HECTD1, and pretreatment of primary mouse astrocytes with BD1047, SB203580, and SP600125 significantly inhibited LPS-mediated translocation of FOXJ2 into the nucleus. Conclusions Overall, our present findings suggest that HECTD1 participates in LPS-induced astrocyte activation by activation of σ-1R-JNK/p38-FOXJ2 pathway and provide a potential therapeutic strategy for neuroinflammation induced by LPS or any other neuroinflammatory disorders.

scholarly journals Role of the C5a-C5a receptor axis in the inflammatory responses of the lungs after experimental polytrauma and hemorrhagic shock

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shinjini Chakraborty ◽  
Veronika Eva Winkelmann ◽  
Sonja Braumüller ◽  
Annette Palmer ◽  
Anke Schultze ◽  
...  
Keyword(s):  
Hemorrhagic Shock ◽  
Inflammatory Responses ◽  
Experimental Models ◽  
Lung Damage ◽  
C5a Receptor ◽  
Cytokine Levels ◽  
Vitro Model

AbstractSingular blockade of C5a in experimental models of sepsis is known to confer protection by rescuing lethality and decreasing pro-inflammatory responses. However, the role of inhibiting C5a has not been evaluated in the context of sterile systemic inflammatory responses, like polytrauma and hemorrhagic shock (PT + HS). In our presented study, a novel and highly specific C5a L-aptamer, NoxD21, was used to block C5a activity in an experimental murine model of PT + HS. The aim of the study was to assess early modulation of inflammatory responses and lung damage 4 h after PT + HS induction. NoxD21-treated PT + HS mice displayed greater polymorphonuclear cell recruitment in the lung, increased pro-inflammatory cytokine levels in the bronchoalveolar lavage fluids (BALF) and reduced myeloperoxidase levels within the lung tissue. An in vitro model of the alveolar-capillary barrier was established to confirm these in vivo observations. Treatment with a polytrauma cocktail induced barrier damage only after 16 h, and NoxD21 treatment in vitro did not rescue this effect. Furthermore, to test the exact role of both the cognate receptors of C5a (C5aR1 and C5aR2), experimental PT + HS was induced in C5aR1 knockout (C5aR1 KO) and C5aR2 KO mice. Following 4 h of PT + HS, C5aR2 KO mice had significantly reduced IL-6 and IL-17 levels in the BALF without significant lung damage, and both, C5aR1 KO and C5aR2 KO PT + HS animals displayed reduced MPO levels within the lungs. In conclusion, the C5aR2 could be a putative driver of early local inflammatory responses in the lung after PT + HS.

scholarly journals The Role of Herbal Bioactive Components in Mitochondria Function and Cancer Therapy

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Fangfang Tao ◽  
Yanrong Zhang ◽  
Zhiqian Zhang
Keyword(s):  
Cancer Therapy ◽  
Cancer Cell ◽  
Apoptotic Cell ◽  
Redox Status ◽  
Cancer Therapies ◽  
Bioactive Components ◽  
Atp Production

Mitochondria are highly dynamic double-membrane organelles which play a well-recognized role in ATP production, calcium homeostasis, oxidation-reduction (redox) status, apoptotic cell death, and inflammation. Dysfunction of mitochondria has long been observed in a number of human diseases, including cancer. Targeting mitochondria metabolism in tumors as a cancer therapeutic strategy has attracted much attention for researchers in recent years due to the essential role of mitochondria in cancer cell growth, apoptosis, and progression. On the other hand, a series of studies have indicated that traditional medicinal herbs, including traditional Chinese medicines (TCM), exert their potential anticancer effects as an effective adjunct treatment for alleviating the systemic side effects of conventional cancer therapies, for reducing the risk of recurrence and cancer mortality and for improving the quality of patients’ life. An amazing feature of these structurally diverse bioactive components is that majority of them target mitochondria to provoke cancer cell-specific death program. The aim of this review is to summarize the in vitro and in vivo studies about the role of these herbs, especially their bioactive compounds in the modulation of the disturbed mitochondrial function for cancer therapy.

scholarly journals Overexposure to apoptosis via disrupted glial specification perturbs Drosophila macrophage function and reveals roles of the CNS during injury

2020 ◽  
Author(s):  
Emma Louise Armitage ◽  
Hannah Grace Roddie ◽  
Iwan Robert Evans
Keyword(s):  
Inflammatory Responses ◽  
Apoptotic Cell ◽  
Calcium Waves ◽  
Apoptotic Cells ◽  
Phagocytic Cells ◽  
Macrophage Function ◽  
Apoptotic Cell Clearance ◽  
Cell Clearance ◽  
Wound Responses

AbstractApoptotic cell clearance by phagocytes is a fundamental process during development, homeostasis and the resolution of inflammation. However, the demands placed on phagocytic cells such as macrophages by this process, and the limitations these interactions impose on subsequent cellular behaviours are not yet clear. Here we seek to understand how apoptotic cells affect macrophage function in the context of a genetically-tractable Drosophila model in which macrophages encounter excessive amounts of apoptotic cells. We show that loss of the glial transcription factor repo, and corresponding removal of the contribution these cells make to apoptotic cell clearance, causes macrophages in the developing embryo to be challenged with large numbers of apoptotic cells. As a consequence, macrophages become highly vacuolated with cleared apoptotic cells and their developmental dispersal and migration is perturbed. We also show that the requirement to deal with excess apoptosis caused by a loss of repo function leads to impaired inflammatory responses to injury. However, in contrast to migratory phenotypes, defects in wound responses cannot be rescued by preventing apoptosis from occurring within a repo mutant background. In investigating the underlying cause of these impaired inflammatory responses, we demonstrate that wound-induced calcium waves propagate into surrounding tissues, including neurons and glia of the ventral nerve cord, which exhibit striking calcium waves on wounding, revealing a previously unanticipated contribution of these cells during responses to injury. Taken together these results demonstrate important insights into macrophage biology and how repo mutants can be used to study macrophage-apoptotic cell interactions in the fly embryo.Furthermore, this work shows how these multipurpose cells can be ‘overtasked’ to the detriment of their other functions, alongside providing new insights into which cells govern macrophage responses to injury in vivo.

scholarly journals Activity of the Pore-Forming Virulence Factor Listeriolysin O Is Reversibly Inhibited by Naturally Occurring S-Glutathionylation

2017 ◽  
Vol 85 (4) ◽  
Author(s):  
Jonathan L. Portman ◽  
Qiongying Huang ◽  
Michelle L. Reniere ◽  
Anthony T. Iavarone ◽  
Daniel A. Portnoy
Keyword(s):  
Protein Function ◽  
Inhibitory Effect ◽  
Cysteine Residue ◽  
Infection Model ◽  
Listeriolysin O ◽  
Content Type ◽  
Pore Forming Proteins

ABSTRACT Cholesterol-dependent cytolysins (CDCs) represent a family of homologous pore-forming proteins secreted by many Gram-positive bacterial pathogens. CDCs mediate membrane binding partly through a conserved C-terminal undecapeptide, which contains a single cysteine residue. While mutational changes to other residues in the undecapeptide typically have severe effects, mutation of the cysteine residue to alanine has minor effects on overall protein function. Thus, the role of this highly conserved reactive cysteine residue remains largely unknown. We report here that the CDC listeriolysin O (LLO), secreted by the facultative intracellular pathogen Listeria monocytogenes, was posttranslationally modified by S-glutathionylation at this conserved cysteine residue and that either endogenously synthesized or exogenously added glutathione was sufficient to form this modification. When recapitulated with purified protein in vitro, this modification completely ablated the activity of LLO, and this inhibitory effect was fully reversible by treatment with reducing agents. A cysteine-to-alanine mutation in LLO rendered the protein completely resistant to inactivation by S-glutathionylation, and a mutant expressing this mutation retained full hemolytic activity. A mutant strain of L. monocytogenes expressing the cysteine-to-alanine variant of LLO was able to infect and replicate within bone marrow-derived macrophages indistinguishably from the wild type in vitro, yet it was attenuated 4- to 6-fold in a competitive murine infection model in vivo. This study suggests that S-glutathionylation may represent a mechanism by which CDC-family proteins are posttranslationally modified and regulated and help explain an evolutionary pressure to retain the highly conserved undecapeptide cysteine.

Lung epithelial NOX/DUOX and respiratory virus infections

2014 ◽  
Vol 128 (6) ◽  
pp. 337-347 ◽  
Author(s):  
Nathalie Grandvaux ◽  
Mélissa Mariani ◽  
Karin Fink
Keyword(s):  
Respiratory Virus ◽  
Inflammatory Responses ◽  
Current Knowledge ◽  
Conditional Knockout ◽  
In Vivo Studies ◽  
Virus Infections ◽  
Lung Epithelial ◽  
Respiratory Virus Infections

Determining the role of NADPH oxidases in the context of virus infection is an emerging area of research and our knowledge is still sparse. The expression of various isoforms of NOX/DUOX (NADPH oxidase/dual oxidase) in the epithelial cells (ECs) lining the respiratory tract renders them primary sites from which to orchestrate the host defence against respiratory viruses. Accumulating evidence reveals distinct facets of the involvement of NOX/DUOX in host antiviral and pro-inflammatory responses and in the control of the epithelial barrier integrity, with individual isoforms mediating co-operative, but surprisingly also opposing, functions. Although in vivo studies in mice are in line with some of these observations, a complete understanding of the specific functions of epithelial NOX/DUOX awaits lung epithelial-specific conditional knockout mice. The goal of the present review is to summarize our current knowledge of the role of individual NOX/DUOX isoforms expressed in the lung epithelium in the context of respiratory virus infections so as to highlight potential opportunities for therapeutic intervention.

scholarly journals HIF-1α is a key mediator of the lung inflammatory potential of lithium-ion battery particles

2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Violaine Sironval ◽  
Mihaly Palmai-Pallag ◽  
Rita Vanbever ◽  
François Huaux ◽  
Jorge Mejia ◽  
...  
Keyword(s):  
Inflammatory Responses ◽  
Hypoxia Inducible Factor ◽  
Lithium Ion ◽  
In Vitro Assays ◽  
Inhalation Toxicity ◽  
Cobalt Nickel ◽  
Occupational Settings

Abstract Background Li-ion batteries (LIB) are increasingly used worldwide. They are made of low solubility micrometric particles, implying a potential for inhalation toxicity in occupational settings and possibly for consumers. LiCoO2 (LCO), one of the most used cathode material, induces inflammatory and fibrotic lung responses in mice. LCO also stabilizes hypoxia-inducible factor (HIF) -1α, a factor implicated in inflammation, fibrosis and carcinogenicity. Here, we investigated the role of cobalt, nickel and HIF-1α as determinants of toxicity, and evaluated their predictive value for the lung toxicity of LIB particles in in vitro assays. Results By testing a set of 5 selected LIB particles (LCO, LiNiMnCoO2, LiNiCoAlO2) with different cobalt and nickel contents, we found a positive correlation between their in vivo lung inflammatory activity, and (i) Co and Ni particle content and their bioaccessibility and (ii) the stabilization of HIF-1α in the lung. Inhibition of HIF-1α with chetomin or PX-478 blunted the lung inflammatory response to LCO in mice. In IL-1β deficient mice, HIF-1α was the upstream signal of the inflammatory lung response to LCO. In vitro, the level of HIF-1α stabilization induced by LIB particles in BEAS-2B cells correlated with the intensity of lung inflammation induced by the same particles in vivo. Conclusions We conclude that HIF-1α, stabilized in lung cells by released Co and Ni ions, is a mechanism-based biomarker of lung inflammatory responses induced by LIB particles containing Co/Ni. Documenting the Co/Ni content of LIB particles, their bioaccessibility and their capacity to stabilize HIF-1α in vitro can be used to predict the lung inflammatory potential of LIB particles.

scholarly journals A novel nucleoside rescue metabolic pathway may be responsible for therapeutic effect of orally administered cordycepin

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Jong Bong Lee ◽  
Masar Radhi ◽  
Elena Cipolla ◽  
Raj D. Gandhi ◽  
Sarir Sarmad ◽  
...  
Keyword(s):  
Oral Administration ◽  
Metabolic Pathway ◽  
Oral Absorption ◽  
Therapeutic Effects ◽  
The Novel ◽  
Drug Candidates ◽  
Biopharmaceutical Properties

Abstract Although adenosine and its analogues have been assessed in the past as potential drug candidates due to the important role of adenosine in physiology, only little is known about their absorption following oral administration. In this work, we have studied the oral absorption and disposition pathways of cordycepin, an adenosine analogue. In vitro biopharmaceutical properties and in vivo oral absorption and disposition of cordycepin were assessed in rats. Despite the fact that numerous studies showed efficacy following oral dosing of cordycepin, we found that intact cordycepin was not absorbed following oral administration to rats. However, 3′-deoxyinosine, a metabolite of cordycepin previously considered to be inactive, was absorbed into the systemic blood circulation. Further investigation was performed to study the conversion of 3′-deoxyinosine to cordycepin 5′-triphosphate in vitro using macrophage-like RAW264.7 cells. It demonstrated that cordycepin 5′-triphosphate, the active metabolite of cordycepin, can be formed not only from cordycepin, but also from 3′-deoxyinosine. The novel nucleoside rescue metabolic pathway proposed in this study could be responsible for therapeutic effects of adenosine and other analogues of adenosine following oral administration. These findings may have importance in understanding the physiology and pathophysiology associated with adenosine, as well as drug discovery and development utilising adenosine analogues.

A Role of Plasminogen in Atherosclerosis and Restenosis Models in Mice

1999 ◽  
Vol 82 (S 01) ◽  
pp. 4-7 ◽  
Author(s):  
Victoria A. Ploplis ◽  
Steven Busuttil ◽  
Peter Carmeliet ◽  
Desire Collen ◽  
Edward F. Plow
Keyword(s):  
Vessel Wall ◽  
Inflammatory Responses ◽  
Leukocyte Migration ◽  
Early Event ◽  
Macrophage Migration ◽  
Murine Models ◽  
Response Models ◽  
Deficient Mice

SummaryIn addition to its preeminent role in fibrinolysis, the plasminogen system is believed to play a key role in mediating cell migration. Leukocyte migration into the vessel wall is a key and early event in the development of the lesions of atherosclerosis and restenosis, pathologies which may be viewed as specific examples of vascular inflammatory responses. The development of mice in which the plasminogen gene has been inactivated affords an opportunity to test the contribution of plasminogen in leukocyte migration during in vivo. This article summarizes recent studies conducted in murine models of the inflammatory repsonse, restenosis and atherosclerosis in which leukocyte migration, and in particular monocyte/macrophage migration, has been evaluated in plasminogen-deficient mice. Recruitment of these cells through the vessel wall in inflammatory response models and into the vessel wall in restenosis and transplant atherosclerosis models is substantially blunted. These data implicate plasminogen in the migration of leukocytes in these murine models. With the numerous correlations between components and/or activation of the plasminogen system in restenosis and atherosclerosis, these results also support a role of plasminogen in the corresponding human pathologies.

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