scholarly journals Porphyromonas gingivalis enhances FasL expression via up-regulation of NFκB-mediated gene transcription and induces apoptotic cell death in human gingival epithelial cells

Microbiology ◽  
2006 ◽  
Vol 152 (3) ◽  
pp. 797-806 ◽  
Author(s):  
Suzana Brozovic ◽  
Rashmita Sahoo ◽  
Shirish Barve ◽  
Hideki Shiba ◽  
Silvia Uriarte ◽  
...  

The interaction between epithelial cells and micro-organisms is often a crucial initiating event in infectious diseases. Infection with Porphyromonas gingivalis, a Gram-negative anaerobe, is strongly associated with severe periodontal disease. This bacterium possesses an array of virulence factors, some of which can induce apoptosis. The tumour necrosis factor (TNF) receptor family is involved in the regulation of cellular homeostasis, cell surface molecules involved in phagocytosis, Fas ligand (L) expression and activation of the caspase cascade resulting in DNA fragmentation and cell blebbing. The current study examined the role of nuclear factor-κB (NFκB) in FasL-mediated apoptotic cell death in primary human gingival epithelial cells (HGEC) induced by heat-killed P. gingivalis, probably through TLR signalling pathways. A marked up-regulation of TLR2 and Fas–FasL was detected in HGEC stimulated with P. gingivalis. Activation of NFκB by P. gingivalis in HGEC was demonstrated by an NFκB promoter luciferase assay as well as by phosphorylation of p65 as detected by Western blotting. Activation of cleaved caspase-3 and caspase-8 resulted in apoptotic cell death of HGEC. The survival proteins c-IAP-1/c-IAP-2 were decreased in HGEC exposed to P. gingivalis. HGEC apoptosis induced by P. gingivalis was inhibited by an anti-human FasL monoclonal antibody. Blockade of NFκB by helenalin resulted in down-regulation of FasL whereas a caspase-8 inhibitor did not decrease FasL. Taken together, these studies show that P. gingivalis can induce epithelial cell apoptosis through Fas–FasL up-regulation and activation of caspase-3 and caspase-8.

2017 ◽  
Vol 45 (07) ◽  
pp. 1497-1511 ◽  
Author(s):  
Shinya Okubo ◽  
Takuhiro Uto ◽  
Aya Goto ◽  
Hiroyuki Tanaka ◽  
Tsuyoshi Nishioku ◽  
...  

Berberine (BBR), an isoquinoline alkaloid, is a well-known bioactive compound contained in medicinal plants used in traditional and folk medicines. In this study, we investigated the subcellular localization and the apoptotic mechanisms of BBR were elucidated. First, we confirmed the incorporation of BBR into the cell visually. BBR showed antiproliferative activity and promptly localized to the nucleus from 5[Formula: see text]min to 15[Formula: see text]min after BBR treatment in HL-60 human promyelocytic leukemia cells. Next, we examined the antiproliferative activity of BBR (1) and its biosynthetically related compounds (2-7) in HL-60 cells. BBR exerted strongest antiproliferative activity among 1-7 and the results of structures and activity relation suggested that a methylenedioxyl group in ring A, an [Formula: see text]-alkyl group at C-9 position, and the frame of isoquinoline may be necessary for antiproliferative activity. Moreover, BBR showed the most potent antiproliferative activity in HL-60 cells among human cancer and normal cell lines tested. Next, we examined the effect of BBR on molecular events known as apoptosis induction. In HL-60 cells, BBR induced chromatin condensation and DNA fragmentation, and triggered the activation of PARP, caspase-3 and caspase-8 without the activation of caspase-9. BBR-induced DNA fragmentation was abolished by pretreatment with inhibitors against caspase-3 and caspase-8, but not against caspase-9. ERK and p38 were promptly phosphorylated after 15 min of BBR treatment, and this was correlated with time of localization to the nucleus of BBR. These results demonstrated that BBR translocated into nucleus immediately after treatments and induced apoptotic cell death by activation of caspase-3 and caspase-8.


Apmis ◽  
2001 ◽  
Vol 109 (10) ◽  
pp. 679-684 ◽  
Author(s):  
J. C. LEE ◽  
J. Y. OH ◽  
K. S. KIM ◽  
Y. W. JEONG ◽  
J. C. PARK ◽  
...  

2021 ◽  
Vol 22 (4) ◽  
pp. 2006
Author(s):  
Mi Jin Kim ◽  
Jinhong Park ◽  
Jinho Kim ◽  
Ji-Young Kim ◽  
Mi-Jin An ◽  
...  

Mercury is one of the detrimental toxicants that can be found in the environment and exists naturally in different forms; inorganic and organic. Human exposure to inorganic mercury, such as mercury chloride, occurs through air pollution, absorption of food or water, and personal care products. This study aimed to investigate the effect of HgCl2 on cell viability, cell cycle, apoptotic pathway, and alters of the transcriptome profiles in human non-small cell lung cancer cells, H1299. Our data show that HgCl2 treatment causes inhibition of cell growth via cell cycle arrest at G0/G1- and S-phase. In addition, HgCl2 induces apoptotic cell death through the caspase-3-independent pathway. Comprehensive transcriptome analysis using RNA-seq indicated that cellular nitrogen compound metabolic process, cellular metabolism, and translation for biological processes-related gene sets were significantly up- and downregulated by HgCl2 treatment. Interestingly, comparative gene expression patterns by RNA-seq indicated that mitochondrial ribosomal proteins were markedly altered by low-dose of HgCl2 treatment. Altogether, these data show that HgCl2 induces apoptotic cell death through the dysfunction of mitochondria.


2001 ◽  
Vol 79 (11) ◽  
pp. 953-958 ◽  
Author(s):  
Ellyawati Candra ◽  
Kimihiro Matsunaga ◽  
Hironori Fujiwara ◽  
Yoshihiro Mimaki ◽  
Yutaka Sashida ◽  
...  

Two steroidal saponins, tigogenin hexasaccharide-1 (TGHS-1, (25R)-5α-spirostan-3β-yl 4-O-[2-O-[3-O- (α-L-rhamnopyranosyl)-β-D-glucopyranosyl]-3-O-[4-O-(α-L-rhamnopyranosyl)-β-D-glucopyranosyl]-β-D-glucopyranosyl]- β-D-galactopyranoside) and tigogenin hexasaccharide-2 (TGHS-2, (25R)-5α-spirostan-3β-yl 4-O-[2-O-[3-O- (β-D-glucopyranosyl)-β-D-glucopyranosyl]-3-O-[4-O-(α-L-rhamnopyranosyl)-β-D-glucopyranosyl]-β-D-glucopyranosyl]- β-D-galactopyranoside), were isolated from the fresh bulbs of Camassia cusickii. In murine leukemic L1210 cells, both compounds showed cytotoxicity with an EC50 value of 0.06 µM. The morphological observation revealed that TGHS-1 and TGHS-2 induced shrinkage in cell soma and chromatin condensation, suggesting apoptotic cell death. The cell death was confirmed to be apoptosis by Annexin V binding to phosphatidylserine in the cell membrane and excluding propidium iodide. A typical apoptotic DNA ladder and the cleavage of caspase-3 were observed after treatment with TGHS-1 and TGHS-2. In the presence of both the compounds, cells with sub-G1 DNA content were detected by flow cytometric analysis, indicating that TGHS-1 and TGHS-2 (each EC50 value of 0.1 µM) are the most powerful apoptotic saponins known. These results suggest that TGHS-1 and TGHS-2 induce apoptotic cell death through caspase-3 activation.Key words: steroidal saponin, tigogenin hexasaccharide, apoptosis, DNA fragmentation, murine leukemic L1210 cells.


Stroke ◽  
2013 ◽  
Vol 44 (suppl_1) ◽  
Author(s):  
Sweena Parmar ◽  
Xiaokun Geng ◽  
Changya Peng ◽  
Murali Guthikonda ◽  
Yuchuan Ding

Objectives: Normobaric oxygenation (NBO) has been shown to provide neuroprotection in vivo and in vitro . Yet, a recent Phase 2 clinical trial investigating NBO therapy in acute ischemic stroke was terminated due to questionable therapeutic benefit. NBO therapy alone may be insufficient to produce improved outcomes. In our recent study, we demonstrated a strong neuroprotective effect of ethanol at a dose of 1.5 g/kg (equivalent to the human legal driving limit). In this study, we sought to identify whether low-dose ethanol administration enhances the neuroprotection offered by NBO and whether combined administration of NBO with ethanol is associated with reduced apoptosis. Methods: Sprague-Dawley rats were subjected to right middle cerebral artery occlusion (MCAO) for 2 h, followed by reperfusion. Ischemic animals received either an intraperitoneal injection of 1.0 g/kg ethanol, 2 h of 100% NBO, or both ethanol and NBO. The Cell Death Detection ELISA Assay (Roche) was performed to determine apoptotic cell death at 24 h after reperfusion. Levels of pro-apoptotic (Caspase-3, Bcl-2-associated X-BAX, and Apoptosis-Inducing Factor-AIF) and anti-apoptotic proteins (Bcl-2 and Bcl-xL) were determined by Western blot analysis at 3 and 24 h after reperfusion. Results: As expected, untreated ischemic rats had the highest apoptotic cell death. Combined NBO/ethanol therapy decreased cell death by 48%, as compared to 29% with ethanol and 22% with NBO. Similarly, combined NBO/ethanol therapy promoted the greatest expression of anti-apoptotic factors and the lowest expression of pro-apoptotic proteins at 3 h after reperfusion. This effect was maintained at 24 h and even more pronounced for AIF and Caspase-3. Conclusions: Given singularly, NBO and ethanol improved the degree of cell death, decreased the expression of pro-apoptotic proteins, and increased the expression of anti-apoptotic proteins. Yet, when administered together, their effects largely compounded. These results suggest a synergistic neuroprotection offered by NBO with ethanol, which may be attributed at least in part to their shared role in modulating neuronal apoptosis.


2004 ◽  
Vol 17 (1) ◽  
pp. 21-30 ◽  
Author(s):  
Anna Csiszar ◽  
Zoltan Ungvari ◽  
Akos Koller ◽  
John G. Edwards ◽  
Gabor Kaley

Previously we demonstrated that aging in coronary arteries is associated with proinflammatory phenotypic changes and decreased NO bioavailability, which, we hypothesized, promotes vascular disease by enhancing endothelial apoptosis. To test this hypothesis we characterized proapoptotic alterations in the phenotype of coronary arteries of aged (26 mo old) and young (3 mo old) F344 rats. DNA fragmentation analysis and TUNEL assay showed that in aged vessels there was an approximately fivefold increase in the number of apoptotic endothelial cells. In aged coronary arteries there was an increased expression of TNFα, TNFβ, and caspase 9 (microarray, real-time PCR), as well as increased caspase 9 and caspase 3 activity, whereas expression of TNFR1, TNFα-converting enzyme (TACE), Bcl-2, Bcl-X(L), Bid, Bax, caspase 8, and caspase 3 were unchanged. In vessel culture (18 h) incubation of aged coronary arteries with a TNF blocking antibody or the NO donor S-nitroso-penicillamine (SNAP) decreased apoptotic cell death. Incubation of young arteries with exogenous TNFα increased caspase 9 activity and elicited endothelial apoptosis, which was attenuated by SNAP. Inhibition of NO synthesis in cultured young coronary arteries also induced apoptotic cell death and potentiated the apoptotic effect of TNFα. Thus we propose that age-related upregulation of TNFα and caspase 9 and decreased bioavailability of NO promote endothelial apoptosis in coronary arteries that may lead to impaired endothelial function and ischemic heart disease in the elderly.


2004 ◽  
Vol 72 (7) ◽  
pp. 3752-3758 ◽  
Author(s):  
Yoonsuk Park ◽  
Özlem Yilmaz ◽  
Il-Young Jung ◽  
Richard J. Lamont

ABSTRACT Porphyromonas gingivalis, one of the causative agents of adult periodontitis, can invade and survive within host epithelial cells. The molecular mechanisms by which P. gingivalis induces uptake and adapts to an intracellular environment are not fully understood. In this study, we have investigated the genetic responses of P. gingivalis internalized within human gingival epithelial cells (GECs) in order to identify factors involved in invasion and survival. We compared the differential display of arbitrarily PCR-amplified gene transcripts in P. gingivalis recovered from GECs with the display of transcripts in P. gingivalis control cultures. Over 20 potential differentially expressed transcripts were identified. Among these, pepO, encoding an endopeptidase, and genes encoding an ATP-binding cassette (ABC) transporter and a cation-transporting ATPase were upregulated in GECs. To investigate the functionality of these gene products, mutants were generated by insertional inactivation. Compared to the parental strain, mutants of each gene showed a significant reduction in their invasion capabilities. In addition, GEC cytoskeletal responses to the mutants were distinct from those induced by the parent. In contrast, adhesion of the mutant strains to GECs was not affected by lack of expression of the gene products. These results suggest that PepO, a cation-transporting ATPase, and an ABC transporter are required for the intracellular lifestyle of P. gingivalis.


2009 ◽  
Vol 37 (2) ◽  
pp. 209-218 ◽  
Author(s):  
Mathieu Vinken ◽  
Elke Decrock ◽  
Elke De Vuyst ◽  
Luc Leybaert ◽  
Tamara Vanhaecke ◽  
...  

This study was set up to critically evaluate a commonly-used in vitro model of hepatocellular apoptotic cell death, in which freshly isolated hepatocytes, cultured in a monolayer configuration, are exposed to a combination of Fas ligand and cycloheximide for six hours. A set of well-acknowledged cell death markers was addressed: a) cell morphology was studied by light microscopy; b) apoptotic and necrotic cell populations were quantified by in situ staining with Annexin-V, Hoechst 33342 and propidium iodide (PI); c) apoptotic and necrotic activities were monitored by probing caspase 3-like activity and measuring the extracellular leakage of lactate dehydrogenase (LDH), respectively; and d) the expression of apoptosis regulators was investigated by immunoblotting. The initiation of apoptosis was evidenced by the activation of caspase 8 and caspase 9, and increased Annexin-V reactivity. Progression through the apoptotic process was confirmed by the activation of caspase 3 and Bid, the enhanced expression of Bax, and the occurrence of nuclear fragmentation. Late transition to a necrotic appearance was demonstrated by an increased number of PI-positive cells and augmented extracellular release of LDH. Thus, the in vitro model allows the study of the entire course of Fas-mediated hepatocellular apoptotic cell death, which is not possible in vivo. This experimental system can serve a broad range of in vitro pharmaco-toxicological purposes, thereby directly assisting in the reduction of animal experimentation.


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