scholarly journals Autophagy Is Involved in Mesenchymal Stem Cell Death in Coculture with Chondrocytes

Cartilage ◽  
2020 ◽  
pp. 194760352094122
Author(s):  
Carlo Alberto Paggi ◽  
Amel Dudakovic ◽  
Yao Fu ◽  
Catalina Galeano Garces ◽  
Mario Hevesi ◽  
...  
Keyword(s):  
Cell Death ◽  
Rna Sequencing ◽  
Human Mscs ◽  
Chondrocyte Proliferation ◽  
Apoptotic Pathway ◽  
Primary Chondrocytes ◽  
Cartilage Formation ◽  
Cell Death Pathways

Objective Cartilage formation is stimulated in mixtures of chondrocytes and human adipose–derived mesenchymal stromal cells (MSCs) both in vitro and in vivo. During coculture, human MSCs perish. The goal of this study is to elucidate the mechanism by which adipose tissue–derived MSC cell death occurs in the presence of chondrocytes. Methods Human primary chondrocytes were cocultured with human MSCs derived from 3 donors. The cells were cultured in monoculture or coculture (20% chondrocytes and 80% MSCs) in pellets (200,000 cells/pellet) for 7 days in chondrocyte proliferation media in hypoxia (2% O2). RNA sequencing was performed to assess for differences in gene expression between monocultures or coculture. Immune fluorescence assays were performed to determine the presence of caspase-3, LC3B, and P62. Results RNA sequencing revealed significant upregulation of >90 genes in the 3 cocultures when compared with monocultures. STRING analysis showed interconnections between >50 of these genes. Remarkably, 75% of these genes play a role in cell death pathways such as apoptosis and autophagy. Immunofluorescence shows a clear upregulation of the autophagic machinery with no substantial activation of the apoptotic pathway. Conclusion In cocultures of human MSCs with primary chondrocytes, autophagy is involved in the disappearance of MSCs. We propose that this sacrificial cell death may contribute to the trophic effects of MSCs on cartilage formation.

scholarly journals Human Monocyte Recognition of Adenosine-Based Cyclic Dinucleotides Unveils the A2a GαsProtein-Coupled Receptor Tonic Inhibition of Mitochondrially Induced Cell Death

2014 ◽  
Vol 35 (2) ◽  
pp. 479-495 ◽  
Author(s):  
Marie Tosolini ◽  
Frédéric Pont ◽  
Delphine Bétous ◽  
Emmanuel Ravet ◽  
Laetitia Ligat ◽  
...  
Keyword(s):  
Cell Death ◽  
Mammalian Cells ◽  
Mitochondrial Permeability Transition ◽  
Human Monocyte ◽  
Inverse Agonist ◽  
Apoptotic Pathway ◽  
Cyclic Dinucleotides ◽  
Agonist Ligands

Cyclic dinucleotides are important messengers for bacteria and protozoa and are well-characterized immunity alarmins for infected mammalian cells through intracellular binding to STING receptors. We sought to investigate their unknown extracellular effects by adding cyclic dinucleotides to the culture medium of freshly isolated human blood cellsin vitro. Here we report that adenosine-containing cyclic dinucleotides induce the selective apoptosis of monocytes through a novel apoptotic pathway. We demonstrate that these compounds are inverse agonist ligands of A2a, a Gαs-coupled adenosine receptor selectively expressed by monocytes. Inhibition of monocyte A2a by these ligands induces apoptosis through a mechanism independent of that of the STING receptors. The blockade of basal (adenosine-free) signaling from A2a inhibits protein kinase A (PKA) activity, thereby recruiting cytosolic p53, which opens the mitochondrial permeability transition pore and impairs mitochondrial respiration, resulting in apoptosis. A2a antagonists and inverse agonist ligands induce apoptosis of human monocytes, while A2a agonists are antiapoptotic.In vivo, we used a mock developing human hematopoietic system through NSG mice transplanted with human CD34+cells. Treatment with cyclic di-AMP selectively depleted A2a-expressing monocytes and their precursors via apoptosis. Thus, monocyte recognition of cyclic dinucleotides unravels a novel proapoptotic pathway: the A2a Gαsprotein-coupled receptor (GPCR)-driven tonic inhibitory signaling of mitochondrion-induced cell death.

scholarly journals Loss of Heterochromatin Protein 1 (HP1) chromodomain function in mammalian cells by intracellular antibodies causes cell death

2002 ◽  
Vol 115 (9) ◽  
pp. 1803-1813 ◽  
Author(s):  
Ilaria Filesi ◽  
Alessio Cardinale ◽  
Sjaak van der Sar ◽  
Ian G. Cowell ◽  
Prim B. Singh ◽  
...  
Keyword(s):  
Cell Death ◽  
Mammalian Cells ◽  
Wide Spectrum ◽  
Human Fibroblasts ◽  
Protein S ◽  
Single Chain ◽  
Heterochromatin Protein 1 ◽  
Apoptotic Pathway

The chromodomain (CD) is a highly conserved motif present in a variety of animal and plant proteins, and its probable role is to assemble a variety of macromolecular complexes in chromatin. The importance of the CD to the survival of mammalian cells has been tested. Accordingly, we have ablated CD function using two single-chain intracellular Fv (scFv) fragments directed against non-overlapping epitopes within the HP1 CD motif. The scFv fragments can recognize both CD motifs of HP1 and Polycomb (Pc) in vitro and, when expressed intracellularly, interact with and dislodge the HP1 protein(s) from their heterochromatin localization in vivo. Mouse and human fibroblasts expressing anti-chromodomain scFv fragments show a cell-lethal phenotype and an apoptotic morphology becomes apparent soon after transfection. The mechanism of cell death appears to be p53 independent, and the cells are only partly rescued by incubation with the wide spectrum caspase inhibitor Z-VAD fmk. We conclude that expression of anti-chromodomain intracellular antibodies is sufficient to trigger a p53-independent apoptotic pathway that is only partly dependent on the known Z-VAD-inhibitable caspases, suggesting that CD function is essential for cell survival.

scholarly journals DOP86 An IFN-STAT1-MLKL axis drives programmed necrosis of Paneth cells in Crohn’s ileitis

2020 ◽  
Vol 14 (Supplement_1) ◽  
pp. S125-S126
Author(s):  
L HARTMANN ◽  
B Siegmund ◽  
C Weidinger ◽  
C Becker ◽  
M F Neurath ◽  
...  
Keyword(s):  
Cell Death ◽  
Intestinal Inflammation ◽  
Paneth Cell ◽  
Signalling Pathways ◽  
Caspase 8 ◽  
Programmed Necrosis ◽  
Cell Death Pathways ◽  
Small Intestinal

Abstract Background Interferons (IFNs) are immune-modulatory cytokines expressed by epithelial and mucosal cells in response to viral and bacterial infection. Just recently, we discovered a correlation between IFN-λ expression and disease activity, including small intestinal inflammation and Paneth cell dysfunction, in human Crohn’s disease patients. On a molecular level, we uncovered that IFN-λ mediates epithelial cell death, in particular, Paneth cell death by a programmed necrosis, dependent on STAT1 activation and controlled by caspase-8. These results suggested that IFN-λ can be considered as a pathogenic cytokine in Crohn′s ileitis and should be considered as a new and promising target for future therapeutic intervention for this particular subtype of IBD. Our central question is now by which pathways interferon-regulated programmed necrosis of epithelial cells contributes to intestinal inflammation and how these mechanisms could be targeted for future therapeutic intervention. Methods We use a mouse model for Crohn’s Disease like inflammation and Paneth cell death that has a specific deletion of Caspase-8 in intestinal epithelial cells (Casp8∆IEC). We stimulate small intestinal organoids derived from Casp8∆IEC mice with IFNs in vitro and we overexpress IFN-λ in these mice in vivo by hydrodynamic tail vein injection of an IFN-λ expression vector. Furthermore, we use JAK-inhibitors to impede pharmacologically cell death pathways in the pathogenesis of intestinal inflammation in vitro and in vivo. Results We uncovered that gene expression of the cell death mediators Mlkl and Caspase-8 is dependent on IFN-λ-mediated JAK-STAT1 signalling. The non-specific pan JAK-inhibitor Tofacitinib is able to attenuate gene expression of Mlkl and Caspase-8 in vitro as well as in vivo. It prevents non-apoptotic as well as apoptotic cell death of small intestinal organoids stimulated with IFN-λ and is sufficient to prevent small intestinal tissue destruction in Casp8∆IEC mice challenged with IFN-λ. Additionally, we use the selective JAK1-inhibitor Filgotinib to limit the targeted JAK-STAT signalling pathways to only JAK1-STAT1 signalling and thus reduce side effects of the inhibitor on other signalling pathways. This had a similar effect as Tofacitinib suggesting that IFN controls MLKL-mediated cell death via JAK1. Conclusion In summary, our results indicate that targeting IFN-λ-mediated JAK-STAT1 signalling by the small-molecules Tofacitinib and Filgotinib impedes induction of Mlkl and Caspase-8-mediated cell death pathways. Therefore, JAK1 inhibitors such as Filgotinib might represent a promising novel therapy that may be sufficient to achieve efficacy particularly in Crohn′s ileitis patients who display elevated IFN-l serum levels.

scholarly journals Novel estradiol analogue induces apoptosis and autophagy in esophageal carcinoma cells

2014 ◽  
Vol 19 (1) ◽  
Author(s):  
Elize Wolmarans ◽  
Thandi Mqoco ◽  
Andre Stander ◽  
Sandra Nkandeu ◽  
Katherine Sippel ◽  
...  
Keyword(s):  
Cell Death ◽  
Esophageal Carcinoma ◽  
Ex Vivo ◽  
Apoptotic Cell ◽  
Critical Role ◽  
Carcinoma Cells ◽  
In Vivo Studies ◽  
Apoptotic Pathway

AbstractCancer is the second leading cause of death in South Africa. The critical role that microtubules play in cell division makes them an ideal target for the development of chemotherapeutic drugs that prevent the hyperproliferation of cancer cells. The new in silico-designed estradiol analogue 2-ethyl-3-O-sulfamoylestra-1,3,5(10)16-tetraene (ESE-16) was investigated in terms of its in vitro antiproliferative effects on the esophageal carcinoma SNO cell line at a concentration of 0.18 μM and an exposure time of 24 h. Polarization-optical differential interference contrast and triple fluorescent staining (propidium iodide, Hoechst 33342 and acridine orange) revealed a decrease in cell density, metaphase arrest, and the occurrence of apoptotic bodies in the ESE-16-treated cells when compared to relevant controls. Treated cells also showed an increase in the presence of acidic vacuoles and lysosomes, suggesting the occurrence of autophagic processes. Cell death via autophagy was confirmed using the Cyto-ID autophagy detection kit and the aggresome detection assay. Results showed an increase in autophagic vacuole and aggresome formation in ESE-16 treated cells, confirming the induction of cell death via autophagy. Cell cycle progression demonstrated an increase in the sub-G1 fraction (indicative of the presence of apoptosis). In addition, a reduction in mitochondrial membrane potential was also observed, which suggests the involvement of apoptotic cell death induced by ESE-16 via the intrinsic apoptotic pathway. In this study, it was demonstrated that ESE-16 induces cell death via both autophagy and apoptosis in esophageal carcinoma cells. This study paves the way for future investigation into the role of ESE-16 in ex vivo and in vivo studies as a possible anticancer agent.

Influence of autophagy, apoptosis and their interplay in filaricidal activity of C-cinnamoyl glycosides

Parasitology ◽  
2019 ◽  
Vol 146 (11) ◽  
pp. 1451-1461 ◽  
Author(s):  
Priya Roy ◽  
Anirban Sengupta ◽  
Nikhilesh Joardar ◽  
Arindam Bhattacharyya ◽  
Nimai Chandra Saha ◽  
...  
Keyword(s):  
Cell Death ◽  
Decisive Role ◽  
Autophagic Flux ◽  
Apoptotic Pathway ◽  
Setaria Cervi ◽  
Cell Death Pathways ◽  
Marker Proteins ◽  
Apoptotic Protein ◽  
Causative Factors

AbstractThe present work aims to explore the mechanism of action of C-cinnamoyl glycoside as an antifilarial agent against the bovine filarial nematode Setaria cervi. Both apoptosis and autophagy programmed cell death pathways play a significant role in parasitic death. The generation of reactive oxygen species, alteration of the level of antioxidant components and disruption of mitochondrial membrane potential may be the causative factors that drive the parasitic death. Monitoring of autophagic flux via the formation of autophagosome and autophagolysosome was detected via CYTO ID dye. The expression profiling of both apoptotic and autophagic marker proteins strongly support the initial findings of these two cell death processes. The increased interaction of pro-autophagic protein Beclin1 with BCL-2 may promote apoptotic pathway by suppressing anti-apoptotic protein BCL-2 from its function. This in turn partially restrains the autophagic pathway by engaging Beclin1 in the complex. But overall positive increment in autophagic flux was observed. Dynamic interaction and regulative balance of these two critical cellular pathways play a decisive role in controlling disease pathogenesis. Therefore, the present experimental work may prosper the chance for C-cinnamoyl glycosides to become a potential antifilarial therapeutic in the upcoming day after detail in vivo study and proper clinical trial.

scholarly journals Mechanism of cell death mediated by a BF2-chelated tetraaryl-azadipyrromethene photodynamic therapeutic: Dissection of the apoptotic pathway in vitro and in vivo

2011 ◽  
Vol 130 (3) ◽  
pp. 705-715 ◽  
Author(s):  
Aisling E. O'Connor ◽  
Margaret M. Mc Gee ◽  
Yury Likar ◽  
Vladimir Ponomarev ◽  
John J. Callanan ◽  
...  
Keyword(s):  
Cell Death ◽  
Apoptotic Pathway

scholarly journals Light-Activated Protoporphyrin IX-Based Polysilsesquioxane Nanoparticles Induce Ferroptosis in Melanoma Cells

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2324
Author(s):  
Hemapriyadarshini Vadarevu ◽  
Ridhima Juneja ◽  
Zachary Lyles ◽  
Juan L. Vivero-Escoto
Keyword(s):  
Cell Death ◽  
Protoporphyrin Ix ◽  
Annexin V ◽  
Special Focus ◽  
Apoptosis Resistance ◽  
Cell Death Mechanism ◽  
Cell Death Pathways ◽  
A Cell

The use of nanoparticle-based materials to improve the efficacy of photodynamic therapy (PDT) to treat cancer has been a burgeoning field of research in recent years. Polysilsesquioxane (PSilQ) nanoparticles with remarkable features, such as high loading of photosensitizers, biodegradability, surface tunability, and biocompatibility, have been used for the treatment of cancer in vitro and in vivo using PDT. The PSilQ platform typically shows an enhanced PDT performance following a cell death mechanism similar to the parent photosensitizer. Ferroptosis is a new cell death mechanism recently associated with PDT that has not been investigated using PSilQ nanoparticles. Herein, we synthesized a protoporphyrin IX (PpIX)-based PSilQ platform (PpIX-PSilQ NPs) to study the cell death pathways, with special focus on ferroptosis, during PDT in vitro. Our data obtained from different assays that analyzed Annexin V binding, glutathione peroxidase activity, and lipid peroxidation demonstrate that the cell death in PDT using PpIX-PSilQ NPs is regulated by apoptosis and ferroptosis. These results can provide alternative approaches in designing PDT strategies to enhance therapeutic response in conditions stymied by apoptosis resistance.

scholarly journals microRNA-377 Signaling Modulates Anticancer Drug-Induced Cardiotoxicity in Mice

2021 ◽  
Vol 8 ◽  
Author(s):  
John Henderson ◽  
Praveen K. Dubey ◽  
Mallikarjun Patil ◽  
Sarojini Singh ◽  
Shubham Dubey ◽  
...  
Keyword(s):  
Cell Death ◽  
Rna Sequencing ◽  
Molecular Mechanisms ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Drug Induced ◽  
Chemotherapy Agent

Doxorubicin (DOX, an anthracycline) is a widely used chemotherapy agent against various forms of cancer; however, it is also known to induce dose-dependent cardiotoxicity leading to adverse complications. Investigating the underlying molecular mechanisms and strategies to limit DOX-induced cardiotoxicity might have potential clinical implications. Our previous study has shown that expression of microRNA-377 (miR-377) increases in cardiomyocytes (CMs) after cardiac ischemia-reperfusion injury in mice, but its specific role in DOX-induced cardiotoxicity has not been elucidated. In the present study, we investigated the effect of anti-miR-377 on DOX-induced cardiac cell death, remodeling, and dysfunction. We evaluated the role of miR-377 in CM apoptosis, its target analysis by RNA sequencing, and we tested the effect of AAV9-anti-miR-377 on DOX-induced cardiotoxicity and mortality. DOX administration in mice increases miR-377 expression in the myocardium. miR-377 inhibition in cardiomyocyte cell line protects against DOX-induced cell death and oxidative stress. Furthermore, RNA sequencing and Gene Ontology (GO) analysis revealed alterations in a number of cell death/survival genes. Intriguingly, we observed accelerated mortality and enhanced myocardial remodeling in the mice pretreated with AAV9-anti-miR-377 followed by DOX administration as compared to the AAV9-scrambled-control-pretreated mice. Taken together, our data suggest that in vitro miR-377 inhibition protects against DOX-induced cardiomyocyte cell death. On the contrary, in vivo administration of AAV9-anti-miR-377 increases mortality in DOX-treated mice.

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