scholarly journals The Role of Caspase-12 in Retinal Bystander Cell Death and Innate Immune Responses against MCMV Retinitis

2021 ◽  
Vol 22 (15) ◽  
pp. 8135
Author(s):  
Xinyan Zhang ◽  
Jinxian Xu ◽  
Brendan Marshall ◽  
Zheng Dong ◽  
Sylvia B. Smith ◽  
...  
Keyword(s):  
Cell Death ◽  
Caspase 3 ◽  
P53 Protein ◽  
Plaque Assay ◽  
Tunel Staining ◽  
Mrna Levels ◽  
Bystander Cell ◽  
Caspase 12 ◽  
Infected Cells ◽  
Bystander Cell Death

(1) Background: caspase-12 is activated during cytomegalovirus retinitis, although its role is presently unclear. (2) Methods: caspase-12−/− (KO) or caspase-12+/+ (WT) mice were immunosup eyes were analyzed by plaque assay, TUNEL assay, immunohistochemical staining, western blotting, and real-time PCR. (3) Results: increased retinitis and a more extensive virus spread were detected in the retina of infected eyes of KO mice compared to WT mice at day 14 p.i. Compared to MCMV injected WT eyes, mRNA levels of interferons α, β and γ were significantly reduced in the neural retina of MCMV-infected KO eyes at day 14 p.i. Although similar numbers of MCMV infected cells, similar virus titers and similar numbers of TUNEL-staining cells were detected in injected eyes of both KO and WT mice at days 7 and 10 p.i., significantly lower amounts of cleaved caspase-3 and p53 protein were detected in infected eyes of KO mice at both time points. (4) Conclusions: caspase-12 contributes to caspase-3-dependent and independent retinal bystander cell death during MCMV retinitis and may also play an important role in innate immunity against virus infection of the retina.

scholarly journals La Crosse Virus Infection of Human Keratinocytes Leads to Interferon-Dependent Apoptosis of Bystander Non-Infected Cells In Vitro

Viruses ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 253 ◽  
Author(s):  
Maria Cruz ◽  
Griffith Parks
Keyword(s):  
Cell Death ◽  
Neutralizing Antibodies ◽  
Human Keratinocytes ◽  
Target Cells ◽  
Hacat Cells ◽  
La Crosse Virus ◽  
Bystander Cell ◽  
Infected Cells ◽  
Bystander Cell Death

Resident cells in the skin serve as the first innate line of defense against insect-borne pathogens, but the role of these cell types in promoting or limiting arbovirus replication is not completely understood. Here, we have examined the outcome of infection of cultured human keratinocyte cells with La Crosse virus (LACV), using a spontaneously transformed cell line, HaCaT. In single cycle infections, keratinocyte HaCaT cells supported rapid and high level LACV replication, resulting in high virus yields and extensive caspase-dependent cell death. By contrast, multi-cycle LACV replication in HaCaT cells was restricted by an antiviral response elicited by the production of both IFN-β and IFN-λ. During low multiplicity LACV infections, HaCaT cell death was seen in non-infected bystander cells. Media from LACV-infected cells induced caspase-dependent killing of naïve non-infected HaCaT cells, and this bystander cell death was relieved by IFN-β neutralizing antibodies or by an inhibitor of JAK-STAT signaling. Naïve HaCaT cells showed dose-dependent killing by treatment with exogenous IFN-β but not IFN-λ. Our data suggest a model whereby keratinocytes produce IFNs which limit virus spread through both antiviral signaling and by induction of bystander cell death of potential new target cells for infection.

Increased cell death in osteopontin-deficient cardiac fibroblasts occurs by a caspase-3-independent pathway

2004 ◽  
Vol 287 (4) ◽  
pp. H1730-H1739 ◽  
Author(s):  
Ron Zohar ◽  
Baoqian Zhu ◽  
Peter Liu ◽  
Jaro Sodek ◽  
C. A. McCulloch
Keyword(s):  
Cell Death ◽  
Caspase 3 ◽  
Cardiac Fibroblasts ◽  
Chromatin Condensation ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Tunel Staining ◽  
Wild Type ◽  
Nuclear Fragmentation ◽  
A Cell

Reperfusion-induced oxidative injury to the myocardium promotes activation and proliferation of cardiac fibroblasts and repair by scar formation. Osteopontin (OPN) is a proinflammatory cytokine that is upregulated after reperfusion. To determine whether OPN enhances fibroblast survival after exposure to oxidants, cardiac fibroblasts from wild-type (WT) or OPN-null (OPN−/−) mice were treated in vitro with H2O2to model reperfusion injury. Within 1 h, membrane permeability to propidium iodide (PI) was increased from 5 to 60% in OPN−/−cells but was increased to only 20% in WT cells. In contrast, after 1–8 h of treatment with H2O2, the percent of terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL)-stained cells was more than twofold higher in WT than OPN−/−cells. Electron microscopy of WT cells treated with H2O2showed chromatin condensation, nuclear fragmentation, and cytoplasmic and nuclear shrinkage, which are consistent with apoptosis. In contrast, H2O2-treated OPN−/−cardiac fibroblasts exhibited cell and nuclear swelling and membrane disruption that are indicative of cell necrosis. Treatment of OPN−/−and WT cells with a cell-permeable caspase-3 inhibitor reduced the percentage of TUNEL staining by more than fourfold in WT cells but decreased staining in OPN−/−cells by ∼30%. Although the percentage of PI-permeable WT cells was reduced threefold, the percent of PI-permeable OPN−/−cells was not altered. Restoration of OPN expression in OPN−/−fibroblasts reduced the percentage of PI-permeable cells but not TUNEL staining after H2O2treatment. Thus H2O2-induced cell death in OPN-deficient cardiac fibroblasts is mediated by a caspase-3-independent, necrotic pathway. We suggest that the increased expression of OPN in the myocardium after reperfusion may promote fibrosis by protecting cardiac fibroblasts from cell death.

scholarly journals The importance of serum serotonin levels in the measurement of radiation-induced bystander cell death in HaCaT cells

2012 ◽  
Vol 88 (10) ◽  
pp. 770-772 ◽  
Author(s):  
Fiona M. Lyng ◽  
Maxime Desplanques ◽  
Kishore Kumar Jella ◽  
Amaya Garcia ◽  
Brendan McClean
Keyword(s):  
Cell Death ◽  
Hacat Cells ◽  
Bystander Cell ◽  
Radiation Induced ◽  
Bystander Cell Death ◽  
Serum Serotonin

scholarly journals Hyperglycemia Enhances DNA Fragmentation after Transient Cerebral Ischemia

2001 ◽  
Vol 21 (5) ◽  
pp. 568-576 ◽  
Author(s):  
Ping-An Li ◽  
Ingrid Rasquinha ◽  
Qing Ping He ◽  
Bo K. Siesjö ◽  
Katalin Csiszár ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Cell Death ◽  
Cytochrome C ◽  
Dna Fragmentation ◽  
Caspase 3 ◽  
Cingulate Cortex ◽  
Tunel Staining ◽  
Dna Fragments ◽  
Cytochrome C Release ◽  
Klenow Polymerase

Previous histopathologic results have suggested that one mechanism whereby hyperglycemia (HG) leads to exaggerated ischemic damage involves fragmentation of DNA. DNA fragmentation in normoglycemia (NG) and HG rats subjected to 30 minutes of forebrain ischemia was studied by terminal deoxynucleotidyl transferase mediated DNA nick-labeling (TUNEL) staining, by pulse-field gel electrophoresis (PFGE), and by ligation-mediated polymerase chain reaction (LM-PCR). High molecular weight DNA fragments were detected by PFGE, whereas low molecular weight DNA fragments were detected using LM-PCR techniques. The LM-PCR procedure was performed on DNA from test samples with blunt (without Klenow polymerase) and 3′-recessed ends (with Klenow polymerase). In addition, cytochrome c release and caspase-3 activation were studied by immunocytochemistry. Results show that HG causes cytochrome c release, activates caspase-3, and exacerbates DNA fragments induced by ischemia. Thus, in HG rats, but not in control or NGs, TUNEL-stained cells were found in the cingulate cortex, neocortex, thalamus, and dorsolateral crest of the striatum, where neuronal death was observed by conventional histopathology, and where both cytosolic cytochrome c and active caspase-3 were detected by confocal microscopy. In the neocortex, both blunt-ended and stagger-ended fragments were detected in HG, but not in NG rats. Electron microscopy (EM) analysis was performed in the cingulate cortex, where numerous TUNEL-positive neurons were observed. Although DNA fragmentation was detected by TUNEL staining and electrophoresis techniques, EM analysis failed to indicate apoptotic cell death. It is concluded that HG triggers a cell death pathway and exacerbates DNA fragmentation induced by ischemia.

scholarly journals The Effect of Kynurenic Acid on Apoptosis in Hepatocellular Carcinoma

Proceedings ◽  
2019 ◽  
Vol 40 (1) ◽  
pp. 6
Author(s):  
Atalay ◽  
Imamoglu
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cell Death ◽  
Glutamate Receptors ◽  
Hepg2 Cells ◽  
Kynurenic Acid ◽  
Caspase 3 ◽  
Mrna Levels ◽  
Antitumor Effects ◽  
Glutamate Antagonists ◽  
Effector Caspase

Kynurenic Acid (KYNA) is a metabolite of tryptophan pathway and also an endogenous antagonist of glutamate receptors. Several studies indicated that glutamate antagonists have anti-proliferative potential. Moreover, subunits of the NMDA receptor which is one of the glutamate receptors have been shown to be found in human hepatocellular carcinoma cell line (HepG2). In this study, the antitumor effects of KYNA in HepG2 cells were investigated for the first time at the molecular level. The effects of KYNA on the viability of HepG2 cells were determined by MTT analyses. Effects of KYNA on mRNA transcriptions of apoptosis related genes Bax, Bcl-2 and Caspase-3 were analyzed by qRT-PCR. mRNA expression analysis revealed that the mRNA levels of effector Caspase-3 and pro-apoptotic Bax/Bcl-2 ratio were not increased in HepG2 cells treated with KYNA. In conclusion, our findings showed that KYNA does not exert its anti-proliferative effects on HepG2 cells through caspase-mediated apoptotic cell death, but it may perform this anti-proliferative effect through a different mechanism of death. Further studies are needed to find out potential cell death mechanisms that may play a role in anti-proliferative activity of KYNA on HepG2 cells.

Abstract 3877: The Magnitude and Temporal Dependence of Apoptosis Early After Myocardial Ischemia with or without Reperfusion

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Christopher French ◽  
A.K.M. Tarikuz Zaman ◽  
Jeffrey L Spees ◽  
Douglas J Taatjes ◽  
Burton E Sobel
Keyword(s):  
Cell Death ◽  
Caspase 3 ◽  
Apoptotic Cell ◽  
Supply And Demand ◽  
Coronary Artery Occlusion ◽  
Artery Occlusion ◽  
Ischemic Myocardium ◽  
Tunel Staining ◽  
Group Averaging ◽  
Myocardial Oxygen Supply

It has been hoped and conjectured that in addition to improving the balance between myocardial oxygen supply and demand amelioration of apoptosis could preserve jeopardized ischemic myocardium destined to undergo necrosis (cell death). Assessment of apoptosis in experimental animals has been based generally on TUNEL assays. Unfortunately, TUNEL positivity occurs with oncotic, mitotic, and autophagic, as well as apoptotic cell death. Accordingly, we characterized the extent of apoptosis after transient or persistent ischemia with highly specific methods. Coronary artery occlusion with and without subsequent revascularization was induced in three groups of 10 week old C57BL/6 mice: those subjected to 1 hr or 4 hr transient ligation followed by 24 hr of reperfusion (1HTLR24H, 4HTLR24H); or 24 hr persistent ligation (24HPL). Apoptosis was quantified throughout the LV by TUNEL, single stranded DNA (ssDNA), and caspase 3 immunohistochemistry, electron microscopy (EM), and caspase 3 and 8 activities assessed biochemically. TUNEL staining markedly exceeded and did not correlate with ssDNA, caspase 3 staining, or apoptosis defined by EM in any group. It was lowest in the 1HTLR24H group (averaging 38.6 of cells ± 3.1% [SEM], n = 9) greater in the 4HTLR24H group (48.5 ± 3.1%, n = 9), and significantly greater than both in the 24HPL group (67.2 ± 4.3%, n = 9, p < 0.01). ssDNA staining was minimal and similar in all three groups and significantly less than TUNEL staining (p < 0.01) (1HTLR24H, 1.0 ± 0.2%, n = 9; 4HTLR24H, 0.8 ± 0.1%, n = 9; 24HPL, 2.9 ± 1.6%, n = 9). Caspase 3 activity/mg protein (1HTLR24H, 15.3 ± 12, n = 3; 4HTLR24H, 58.5 ± 4, n = 3; 24HPL, 56.5 ± 10, n = 3) was similar to that in normal hearts (53.2 ± 11, n = 4), as was caspase 8 activity. No cleaved caspase 3 was seen immunohistochemically, and only rare, definitively identified apoptotic cells were seen by EM in hearts from any group. Apoptosis is de minimus early after transitory or persistent ischemia contrary to its overestimated, large extent as judged from TUNEL. Thus, antiapoptotic interventions per se are not likely to preserve substantial amounts of jeopardized ischemic myocardium early after ischemic insults.

scholarly journals Late-emerging strains of HIV induce T-cell homeostasis failure by promoting bystander cell death and immune exhaustion in naïve CD4 and all CD8 T-cells

2014 ◽  
Vol 83 (1) ◽  
pp. 69-73 ◽  
Author(s):  
Catherine N. Kibirige ◽  
Frederick A. Menendez ◽  
Hao Zhang ◽  
Tricia L. Nilles ◽  
Susan Langan ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Death ◽  
T Cell ◽  
Cd8 T Cells ◽  
Bystander Cell ◽  
T Cell Homeostasis ◽  
Cell Homeostasis ◽  
Immune Exhaustion ◽  
Bystander Cell Death

scholarly journals Gap Junctions Mediate Bystander Cell Death in Developing Retina

2003 ◽  
Vol 23 (16) ◽  
pp. 6413-6422 ◽  
Author(s):  
Karen Cusato ◽  
Alejandra Bosco ◽  
Renato Rozental ◽  
Cinthya A. Guimarães ◽  
Benjamin E. Reese ◽  
...  
Keyword(s):  
Cell Death ◽  
Gap Junctions ◽  
Bystander Cell ◽  
Bystander Cell Death

scholarly journals Gasdermine E-Dependent Mitochondrial Pyroptotic Pathway in Dermatomyositis: A Possible Mechanism of Perifascicular Atrophy

2020 ◽  
Vol 79 (5) ◽  
pp. 551-561
Author(s):  
Meirong Liu ◽  
Ling Li ◽  
Tingjun Dai ◽  
Ying Hou ◽  
Wei Li ◽  
...  
Keyword(s):  
Cell Death ◽  
Caspase 3 ◽  
Immunohistochemical Analysis ◽  
Positive Staining ◽  
Mrna Levels ◽  
Mitochondrial Apoptosis ◽  
Histologic Feature ◽  
Caspase 9 ◽  
Perifascicular Atrophy ◽  
And Control

Abstract Different mechanisms have been proposed to explain the pathological basis of perifascicular atrophy (PFA), a pathognomonic histologic feature of dermatomyositis (DM); however, the detailed mechanisms remain to be elucidated. There is mitochondrial dysfunction in PFA and expression of mitochondrial apoptosis molecules has been reported in DM. Overexpression of gasdermin E (GSDME) can turn mitochondrial apoptosis to mitochondrial pyroptosis, a newly characterized form of programmed cell death. We determined the expression of proteins involved in the caspase-3- and GSDME-dependent mitochondrial pyroptotic pathway, including BAX, BAK, cytochrome C, caspase-9, caspase-3, GSDME, and IL-1α, in biopsied muscles from DM and control patients. Immunohistochemical analysis showed that those markers were expressed in most fibers in PFA in DM. GSDME-positive and IL-1α-positive staining was mainly localized around punched-out vacuoles or sarcolemma. These markers were significantly upregulated at the protein and mRNA levels in DM versus controls. Our results suggest that caspase-3- and GSDME-dependent mitochondrial pyroptosis are involved in the pathogenetic mechanisms of PFA in DM and that targeting GSDME-dependent mitochondrial pyroptosis may be an effective therapeutic approach for this condition.

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