scholarly journals Real-Time Induction of Macrophage Apoptosis, Pyroptosis, and Necroptosis by Enterococcus faecalis OG1RF and Two Root Canal Isolated Strains

Author(s):  
Danlu Chi ◽  
Xinwei Lin ◽  
Qingzhen Meng ◽  
Jiali Tan ◽  
Qimei Gong ◽  
...  

To investigate the effects of two Enterococcus faecalis root canal isolated strains (CA1 and CA2) and of the OG1RF strain on apoptosis, pyroptosis, and necroptosis in macrophages. The virulence factors of E. faecalis CA1 and CA2 pathogenic strains were annotated in the Virulence Factors Database (VFDB). E. faecalis CA1, CA2, and OG1RF strains were used to infect RAW264.7 macrophages (MOI, 100:1). We assessed the viability of intracellular and extracellular bacteria and of macrophages at 2, 6, and 12 h post-infection. We used a live cell imaging analysis system to obtain a dynamic curve of cell death after infection by each of the three E. faecalis strains. At 6 and 12 h post-infection, we quantified the mRNA expression levels of PANoptosis-related genes and proteins by RT-qPCR and western blot, respectively. We identified ultrastructural changes in RAW264.7 cells infected with E. faecalis OG1RF using transmission electron microscopy. We found 145 and 160 virulence factors in the CA1 and CA2 strains, respectively. The extracellular CA1 strains grew faster than the CA2 and OG1RF strains, and the amount of intracellular viable bacteria in the OG1RF group was highest at 6 and 12 h post-infection. The macrophages in the CA1 infection group were the first to reach the maximum PI-positivity in the cell death time point curve. We found the expressions of mRNA expression of caspase-1, GSDMD, caspase-3, MLKL, RIPK3, NLRP3, IL-1β and IL-18 and of proteins cleaved caspase-1, GSDMD, cleaved caspase-3 and pMIKL in the macrophages of the three infection groups to be upregulated (P<0.05). We detected ultrastructural changes of apoptosis, pyroptosis, and necroptosis in macrophages infected with E. faecalis. The three E. faecalis strains induced varying degrees of apoptosis, pyroptosis, and necroptosis that were probably associated with PANoptosis in macrophages. The E. faecalis CA1 strain exhibited faster growth and a higher real-time MOI, and it induced higher expression levels of some PANoptosis-related genes and proteins in the infected macrophages than the other strains tested.

2018 ◽  
Vol 51 (4) ◽  
pp. 1982-1995 ◽  
Author(s):  
Yuji Kaneko ◽  
Julian P. Tuazon ◽  
Xunming Ji ◽  
Cesario V. Borlongan

Background/Aims: The endogenous neurotrophic peptides pituitary adenylate cyclase-activating polypeptides (PACAP-27/38) protect against stroke, but the molecular mechanism remains unknown. Methods: Primary rat neural cells were exposed to PACAP-27 or PACAP-38 before induction of experimental acute ischemic stroke via oxygen-glucose deprivation-reperfusion (OGD/R) injury. To reveal PACAP’s role in neuroprotection, we employed fluorescent live/dead cell viability and caspase 3 assays, optical densitometry of mitochondrial dehydrogenase and cell growth, glutathione disulfide luciferase activity, ELISA for high mobility group box1 extracellular concentration, ATP bioluminescence, Western blot analysis of PACAP, NMDA subunits, apoptosis regulator Bcl-2, social interaction hormone oxytocin, and trophic factor BDNF, and immunocytochemical analysis of PACAP. Results: Both PACAP-27 and PACAP-38 (PACAP-27/38) increased cell viability, decreased oxidative stress-induced cell damage, maintained mitochondrial activity, prevented the release of high mobility group box1, and reduced cytochrome c/caspase 3-induced apoptosis. PACAP-27/38 increased the protein expression levels of BDNF, Bcl-2, oxytocin, and precursor PACAP. N-methyl-D-aspartate receptor (NMDAR)-induced excitotoxicity contributes to the cell death associated with stroke. PACAP-27/38 modulated the protein expression levels of NMDAR subunits. PACAP-27/38 increased the protein expression levels of the GluN1 subunit, and decreased that of the GluN2B and GluN2D subunits. PACAP-27, but not PACAP-38, increased the expression level of the GluN2C subunit. Conclusion: This study provides evidence that PACAP regulated NMDAR subunits, affording neuroprotection after OGD/R injury.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Rochelle A. Flores ◽  
Cherry P. Fernandez-Colorado ◽  
Fahmida Afrin ◽  
Paula Leona T. Cammayo ◽  
Suk Kim ◽  
...  

Abstract R. anatipestifer (RA) is one of the most harmful bacterial pathogens affecting the duck industry, and infection is associated with the production of proinflammatory cytokines, including IL-17A. Another proinflammatory cytokine, IL-23, is critical for the development of Th17 cells, which produce IL-17. However, IL-23 roles have not been studied in this infection. Here, we describe the identification and mRNA expression analysis of duck IL-23p19 (duIL-23p19) in splenic lymphocytes and macrophages stimulated with killed RA and in spleens of RA-infected ducks. Expression of duIL-23p19 transcript identified in this study was relatively high in livers of healthy ducks and was upregulated in mitogen-activated splenic lymphocytes as well as in splenic lymphocytes and macrophages stimulated with killed RA. In spleens of RA-infected ducks, expression levels of duIL-23p19 transcript were unchanged at all time points except on days 4 and 7 post-infection; however, duIL-17A and IL-17F expression levels were upregulated in both spleens of RA-infected ducks and splenic lymphocytes and macrophages stimulated with killed RA. In sera collected at 24 h after this infection, duIL-23p19 expression levels were unchanged, whereas IL-17A significantly upregulated. These results suggest that IL-23p19 does not play a critical role in the IL-17A response in early stages of RA-infected ducks.


2009 ◽  
Vol 27 (15_suppl) ◽  
pp. e15071-e15071
Author(s):  
H. Kuramochi ◽  
K. Hayashi ◽  
G. Nakajima ◽  
H. Kamikozuru ◽  
M. Yamamoto

e15071 Background: Oxaliplatin has been widely used for the treatment of colorectal cancer. The mechanism of action of platinum compounds such as oxaliplatin is to bind to a DNA molecule in the form of a platinum-DNA-adduct. Excision repair cross complementation group 1 (ERCC1), which plays a major role in the nucleotide excision pathway, has a polymorphism in codon 118, and is reported to be associated with a resistance to platinum-based therapy. Thymidylate synthase (TS) and dehydropyrimidine dehydrogenase (DPD) are key enzymes of 5-FU metabolism and are well known to be associated with a response to 5-FU-based therapy. Methods: Twenty-one colorectal cancer patients (male:female = 7:14; median age, 65) treated with a combination of oxaliplatin and S-1 as a first-line therapy were analyzed for ERCC1 codon 118 polymorphism and the mRNA expression levels of TS, ERCC1, and DPD. Formalin-fixed paraffin- embedded surgical specimens were used and t-RNA and DNA were extracted. The mRNA expression levels were measured using real-time RT-PCR, and the polymorphism was analyzed using the allelic discrimination method together with real-time PCR. Results: No correlation was observed between ERCC1 codon118 polymorphism and any response to the chemotherapy. ERCC1 mRNA levels tended to be higher in the patients with wild-type homozygous alleles in codon 118 than in those with at least one mutant allele(1.19 vs.0.68: p= 0.15). Patients with both high TS and ERCC1 mRNA levels showed a significantly lower response rate than the others (25% vs. 67%, p=0.02). No relationship was seen between DPD mRNA expression levels and the response. Conclusions: The mRNA expression levels of TS and ERCC1 appear to be useful markers for the treatment of S-1 and oxaliplatin. No particular usefulness of ERCC1 codon 118 polymorphism was verified. No significant financial relationships to disclose.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 5564-5564
Author(s):  
Kimiyoshi Sakaguchi ◽  
Hiroyoshi Takahashi

Abstract Introduction Advances in chemotherapy have improved the outcome of childhood acute lymphoblastic leukemia (ALL). However, leukemia cells in refractory ALL are often resistant to anti-leukemic agents. Although recent studies have focused on the epigenetic changes in refractory leukemia, the relationship between the demethylating agent 2′-deoxy-5-azacytidine (decitabine, DAC) and ALL remains unclear. Here, we examine the combined effects of DAC and anti-leukemic agents such as clofarabine (CLO) and etoposide (ETO) on the ALL cell line CCRF-CEM. Methods and results In vitro drug sensitivity was measured using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay. We cultured CCRF-CEM cells for 72 hours with or without DAC, and then removed DAC (when present) prior to culturing CCRF-CEM cells for 48 hours with ETO or CLO, or without chemotherapeutic drugs. After culturing for 48 hours, we removed the chemotherapeutic drugs and measured in vitro drug sensitivity using MTT assay. The MTT assay was performed in triplicate. We then evaluated the inhibitory concentration at 50% (IC50). IC50 for ETO, ETO+DAC, CLO, and CLO+DAC was 3.36, 0.625, 4.96, and 1.92, respectively. The combination Index (CI) was produced with Calcusyn® software, which uses the methodology of Chou and Talalay to perform formal synergy analyses. A CI < 1 indicated a synergistic effect. The CI was 0.026 for ETO+DAC and 0.431 for CLO+DAC. We assayed with Annexin-V, PI staining, and caspase-3/7 to detect apoptosis. We observed apoptosis rates of 31.6%, 53.3%, 31.2%, and 52.6% for ETO, ETO+DAC, CLO, and CLO+DAC, respectively. We observed greater caspase-3/7 activity with DAC+CLO and DAC+ETO than with CLO and ETO. Using real-time reverse transcription polymerase chain reaction (RT-qPCR) in CCRF-CEM cells, we examined mRNA expression levels for the pro-apoptotic genes BAK, BID, BAX, BAD, BIM, PUMA, ATM, TP53, and NOXA, as well as those for the anti-apoptotic genes BCL2, BCL2L1, and XIAP. The expression level of each target gene was calculated by normalizing it to the housekeeping gene GAPDH. The RT-qPCR was performed in triplicate. We used Student’s t test to compare the data. We observed DAC increased mRNA expression levels of BAX and NOXA, but decreased those for BAK, BID, PUMA, BCL2L1, ATM, TP53, and XIAP. We then analyzed the methylation status of pro- and anti-apoptotic genes after 48 hours incubation with or without DAC. Methylation status of BAK, NOXA, BCL2L1 and XIAP incubation with DAC was 1.3%, 3.3%, 2.5% and 72.9%, respectively. Methylation status of BAK, NOXA, BCL2L1 and XIAP incubation without DAC was 1.9%, 3.6%, 0.7% and 92.3%, respectively. There was no significant difference. Discussion Our results showed that DAC synergistically enhances CLO and ETO cytotoxicity, and this cytotoxic effect depends on caspase-3/7 activity. We examined mRNA expression levels of pro- and anti-apoptotic genes. We hypothesized that DAC would increase mRNA expression levels of most pro-apoptotic genes, and decrease mRNA levels of most anti-apoptotic genes. We found that DAC decreased some pro-apoptotic genes, such as BAK, BID, PUMA, ATM, and TP53, which disproves our hypothesis. Our present findings are similar to those of Shin et al., who reported that DAC decreased BID mRNA expression levels. However, they provided no explanation for this activity. Our results show that DAC did not demethylate the CpG of BAK, NOXA, BCL2L1, or XIAP. Thus, DAC must demethylate the CpG of other genes. Nevertheless, many genes are involved in apoptosis, and it remains unclear which genes are demethylated by DAC. Disclosures: Sakaguchi: Yakult Honsha Company: Research Funding; Japan Leukemia Research Fund: Research Funding; Japan Society for the Promotion of Science: Research Funding; Sanofi: Research Funding; Teijin Pharma: Research Funding.


2016 ◽  
Vol 94 (9) ◽  
pp. 1015-1022 ◽  
Author(s):  
T.R. Anju ◽  
P.R. Akhilraj ◽  
C.S. Paulose

Neonatal hypoglycemia limits glucose supply to cells leading to long-term consequences in brain function. The present study evaluated antioxidant and cell death factors’ alterations in cerebral cortex of 1-month-old rats exposed to neonatal hypoglycemia. Gene expression studies by real-time PCR were carried out using gene-specific TaqMan probes. Fluorescent dyes were used for immunohistochemistry and nuclear staining and imaged by confocal microscope. Total antioxidant level and expression of antioxidant enzymes — superoxide dismutase (SOD) and gluthathione peroxide (GPx) — mRNA was significantly reduced along with high peroxide level in the cerebral cortex of 1-month-old rats exposed to neonatal hypoglycemia. Real-time PCR analysis showed an upregulation of Bax, caspase 3, and caspase 8 gene expression. Confocal imaging with TOPRO-3 staining and immunohistochemistry with caspase 3 antibody indicated cell death activation. The reduced free radical scavenging capability coupled with the expression of key factors involved in cell death pathway points to the possibility of oxidative stress in the cortex of 1-month-old rats exposed to neonatal hypoglycemia. The observed results indicate the effects of neonatal hypoglycemia in determining the antioxidant capability of cerebral cortex in a later stage of life.


2020 ◽  
Author(s):  
Xinyan Zhang ◽  
Linlin Zhang ◽  
Yidan Bi ◽  
Ting Xi ◽  
Zhan Zhang ◽  
...  

Abstract Background:Cytomegalovirus (CMV) could induce autophagy early upon infection, which might have an impact on virus replication and the survival of host cells. The purpose ofthe present study was to determine how autophagy effects virus replication and whether it is associated with caspase-3 dependent apoptosis duringmurine cytomegalovirus (MCMV) infection. Methods:The eyecup isolated from adultC57BL/6J mice (6-8 weeks old) and mouse embryo fibroblast cells (MEFs) were cultured and infected with MCMV K181 strain, following by treated with 3-methyladenine (3-MA)or rapamycin to block or activate autophagy.Immunofluorescence staining and western blot were used to detect the expression of early antigen (EA) of MCMV, autophagy and cell death related factors. Plaque assay was performed to detect the virus titer in different groups. TUNEL assay was used to measure the percentage of cell death.Results: Results showed that autophagy was induced at 24,72 and 96hours post infection (hpi)with MCMV in MEFs. In the eyecup culture, it also showed that autophagy was induced at 4 and 7days post infection (dpi).In addition, caspase-3 dependent apoptosis and receptor-interacting kinase 1/ receptor-interacting kinase 3/mixed lineage kinase domain-like protein (RIPK1/RIPK3/MLKL) dependent necroptosis were induced by MCMV infection in eyecup.In MEFs, caspase-3 dependent apoptosis was inhibited, whileRIPK1/RIPK3/MLKL dependent necroptosis was activated with MCMV infection. Once treatment with 3-MA, there were significantly less active virus particles released in MEFs and eyecup, also EA expression was significantly inhibited in the eyecup. However, treatment with rapamycin have no such significant influence on either virus titer or EA expression in MEFs and eyecup. Furthermore, cleaved caspase-3 was elevated, while RIPK1/RIPK3/MLKL pathway was inhibited with treatment of 3-MA both in MEFs and eyecup. Conclusion:Inhibition of autophagy by 3-MA could both restrict virus replication and promote caspase-3 dependent apoptosis in the eyecup and MEFs with MCMV infection.It can be explained that on the early periodof MCMV infection, suppressed autophagy process directly reduced virus release.Thereafter, caspase-3 dependent apoptosis was activated and resulted in decreased virus replication.


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