• Biomedical Science Letters
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• v.13 no.4
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• pp.279-285
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• 2007

Although retinoic acid has been known as either anti-inflammatory or pro-inflammatory molecule, depending on the cell type, its exact role in mature human neutrophils has not been fully explored. In this study, we investigate the effects of retinoic acid on neutrophil apoptosis and the associated mechanism and found that 9-cis retinoic acid (9CRA) significantly inhibits the spontaneous apoptosis of neutrophils. Its effect is increased by co-treatment with $TNF-\alpha$ (P<0.05). The 9CRA-induced inhibition is blocked by the following enzyme inhibitors: Ly 294002, phosphoinoside (PI)-3 kinase inhibitor, U73122, a phospholipase C (PLC) inhibitor, PP2, Src family protein inhibitor, SB202190, p38 MAPK inhibitor, and BAY-11-7085, NF-kB inhibitor. This study also demonstrates that all-trans retinoic acid suppresses spontaneous apoptosis, similar to the mechanism of inhibition exhibited by 9CRA. Phosphorylation of p38 MAPK decreases by 9CRA treatment. $Ik-B{\alpha}$ is degraded until 30 minutes after a time-dependent 9CRA treatment, but degradation can be inhibited by Ly 294002. These results indicate that 9CRA decreases p38 MAPK activation, induces NF-kB activation via PI-3 kinase, and also blocks cleavage of caspase 3. As these findings suggest, 9CRA has a molecular mechanism which may help pro-inflammatory response by blocking neutrophil apoptosis.

• Journal of Microbiology and Biotechnology
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• v.32 no.6
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• pp.792-799
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• 2022

As a vital problem in reproductive health, recurrent spontaneous abortion (RSA) affects about 1% of women. We performed this study with an aim to explore the molecular mechanism of interleukin-23 (IL-23) and find optimal or effective methods to improve RSA. First, ELISA was applied to evaluate the expressions of IL-23 and its receptor in HTR-8/SVneo cells after IL-23 treatment. CCK-8, TUNEL, wound healing and transwell assays were employed to assess the proliferation, apoptosis, migration and invasion of HTR-8/SVneo cells, respectively. Additionally, the expressions of apoptosis-, migration-, epithelial-mesenchymal transition- (EMT-) and p38 MAPK signaling pathway-related proteins were measured by western blotting. To further investigate the relationship between IL-23 and p38 MAPK signaling pathway, HTR-8/SVneo cells were treated for 1 h with p38 MAPK inhibitor SB239063, followed by a series of cellular experiments on proliferation, apoptosis, migration and invasion, as aforementioned. The results showed that IL-23 and its receptors were greatly elevated in IL-23-treated HTR-8/SVneo cells. Additionally, IL-23 demonstrated suppressive effects on the proliferation, apoptosis, migration, invasion and EMT of IL-23-treated HTR-8/SVneo cells. More importantly, the molecular mechanism of IL-23 was revealed in this study; that is to say, IL-23 inhibited the proliferation, apoptosis, migration, invasion and EMT of IL-23-treated HTR-8/SVneo cells via activating p38 MAPK signaling pathway. In conclusion, IL-23 inhibits trophoblast proliferation, migration, and EMT via activating p38 MAPK signaling pathway, suggesting that IL-23 might be a novel target for the improvement of RSA.

• Tuberculosis and Respiratory Diseases
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• v.54 no.5
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• pp.495-509
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• 2003

Background : Neutrophil-mediated inflammation is usually self-limiting, because neutrophils have a remarkably short life span. Prolonged neutrophil survival, which is caused by decreased spontaneous apoptosis, leads to persistent inflammation in sepsis. Because many inflammatory cytokines, which generate signals that delay apoptosis, are regulated by nuclear factor-${\kappa}B$ transcription factor, we hypothesized that nuclear factor-${\kappa}B$ might be related to the reduced neutrophil apoptosis observed in sepsis. Methods : Neutrophils of healthy volunteers and sepsis patients were freshly isolated from venous blood. Neutrophil apoptosis was assayed with two approaches : by counting apoptotic cells under a microscope and by flow cytometry using Annexin V. The activity of nuclear factor-${\kappa}B$ was assessed by immunofluorescent staining or electrophoretic mobility shift assay. Expression of X-linked inhibitor of apoptosis was measured by western blot assay. Results : We confirmed reduced spontaneous neutrophil apoptosis in patients with sepsis. The number of apoptotic neutrophils in patients with sepsis increased to the level of that in healthy controls after cycloheximide treatment, suggesting that decreased spontaneous neutrophil apoptosis is dependent on de novo protein synthesis. In patients with sepsis, basal neutrophil nuclear factor-${\kappa}B$ was activated compared to the level in healthy controls. Moreover, a blockade of nuclear factor-${\kappa}B$ activity reversed the decreased spontaneous neutrophil apoptosis in sepsis patients. Meanwhile, X-linked inhibition of apoptosis expression, which is regulated by nuclear factor-${\kappa}B$, decreased 24 hours after incubation in healthy persons, but persisted for 24 hours in patients with sepsis. Conclusion : These observations suggest that the reduced spontaneous neutrophil apoptosis observed in patients with sepsis may be related to the induction of survival protein by nuclear factor-${\kappa}B$.

• Biomedical Science Letters
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• v.21 no.2
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• pp.122-125
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• 2015

House dust mite (HDM) as a major allergen and damage-associated molecular pattern (DAMP) such as S100A8 and S100A9 trigger the pathogenesis and severity of allergic disease such as asthma. Regulation of neutrophil apoptosis is an important immune response and its dysregulation is involved in pathogenesis of allergic diseases. In this study, we examined the effects of HDM, S100A8 and S100A9 on spontaneous apoptosis of normal neutrophils. We considered the importance of the difference between in vitro and in vivo results and developed a new in vitro system consisting of a combination of immune cells and T helper (Th) cytokines. Extract of Dermatophagoides pteronyssinus (DP), S100A8, and S100A9 inhibited neutrophil apoptosis in culture of neutrophils alone without other leukocytes. DP and S100A8 more strongly suppressed neutrophil apoptosis in combinations of neutrophils, eosinophils, lymphocytes or monocytes than in a culture of neutrophils alone. Anti-apoptotic effect of S100A9 in the mixture of immune cells was similar to that in neutrophils. DP, S100A8, and S100A9 blocked neutrophil apoptosis, regardless of pretreatment with a T helper (Th) 1 cytokine (IFN-$\gamma$), Th2 cytokines (IL-4 and IL-10), a Th9 cytokine (IL-9), a Th17 cytokine (IL-17), a Treg-producing cytokine (TGF-$\beta$). These findings may enable elucidation of allergy pathogenesis due to HDM and DAMP.

• Proceedings of the KSAR Conference
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• 2002.06a
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• pp.4-4
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• 2002

Male germ cell apoptosis has been extensively explored in rodent. In contrast, very little is known about their susceptibility to apoptosis stimuli of developing germ cell stages at the time when germ cell depletion after busulfan treatment occurs. Furthermore, it is still unanswered how spermatogonial stem cells are resistant to busulfan treatment. Spontaneous apoptosis of germ cells was observed in the testis of adult mice and experimentally induced busulfan treated mice increased this apoptosis to such an extent that there was a decrease in the weight of the testis. (omitted)

• Biomedical Science Letters
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• v.22 no.4
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• pp.211-214
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• 2016

House dust mite is an essential allergen in the pathogenesis of allergic diseases. Abnormal regulation of neutrophil apoptosis is an important pathogenic process in allergic diseases. In the present study, we investigated the effects of house dust mites on spontaneous apoptosis of neutrophils and its associated mechanisms. Extract of Dermatophagoides pteronissinus (DP) inhibited neutrophil apoptosis in a time-dependent manner. Cycloheximide (CHX), an inhibitor of translation, increased apoptosis of DP-treated neutrophils as well as control cells. The pro-apoptotic effect of CHX was blocked by DP in neutrophils. In addition, DP increased the phosphorylation of Bad in a time-dependent manner, indicating that it exerted an inhibitory effect on the function of Bad. These results suggest that DP has anti-apoptotic effects of neutrophils and may regulate protein synthesis and activation of Bad. Moreover, these findings may shed light on elucidation of allergy pathogenesis due to house dust mites.

• Journal of Life Science
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• v.16 no.1
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• pp.30-36
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• 2006

Neutrophils are short-lived leukocytes that play a vital role in immune responses to bacteria, yeast, and fungi. This study was performed to investigate the effect of 4-O-methyl-ascochlorin (MAC), an anti-tumor, antibiotic, and anti-fungal prenyl-phenol compound on the spontaneous apoptosis of human neutrophils. MAC time- and dose-dependently accelerated the spontaneous apoptosis of human neutrophils. The effect of MAC on neutrophil apoptosis was blocked by pre-treatment of the neutrophils with specific inhibitors of pancaspase (zVAD-fmk), caspase-8 (zIETD-fmk), or caspase-3 (zDEVD-fmk). The cleavage of procaspase-8 and procaspase-3 was increased by MAC. Mitochondrial permeability, which was measured by the retention of $DiOC_6(3)$, was dose-de-pendently increased by MAC but the change of mitochondrial permeability was not blocked by pretreatment of neutrophils with zIETD-fmk. These results suggest that MAC induces neutrophil apoptosis by caspase-8-dependent but mitochondria-independent manner.

• Toxicological Research
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• v.17 no.4
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• pp.241-248
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• 2001

Exposure to 2-Bromopropane has been known to cause degeneration of male germ cells. However the mechanism underlying this process is poorly understood. The objective of this study was to determine whether or not the exposure of male Sprague-Dawley rats to 2-BP induces apoptosis in male germ cells. Male rats(N=3 or 4 in each group) were orally administered either with the corn oil vehicle (10 ml/kg body weight) or with 2-BP (3,500 mg/kg) once a day for 3 days. The presence of apoptosis was determined by TUNEL detection in situ and by an increase in DNA fragmentation. A low spontaneous incidence of apoptosis was observed in vehicle control animals, especially in pre-meiotic germ cells of stages I-VI and stages XII-XIV the seminiferous tubules. In 2-BP exposure rats, the incidence of apoptosis markedly increased at 4 h, reached a peak at 8 h (about 7-fold over control), and then decreased rapidly to control level by 48 h after the last administration. Although apoptosis induced by 2-BP occurred in all stages of germ cells, it was most pronounced in spermatogonia and early spermatocytes in stages I-VI and stages XII-XIV. Taken together, our results suggest that apoptosis is involved in the toxicity of testicular germ cells resulting in oligospermia or azoospermia after exposure to 2-BP.

• Radiation Oncology Journal
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• v.17 no.3
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• pp.203-208
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• 1999

Purpose : To evaluate whether spontaneous apoptosis has prognostic value among patients with squamous cell carcinoma of lung. Materials and Methods : Material from 19 patients who received thoracic irradiation between 1990 and 1994 was analyzed. Their stages were II (1), IIIa (8), IIIb (5), and IV (5). Patients were observed from 5 to 67 months (median : 17 months). The spontaneous apoptosis index (AI) and p53 mutation were measured by immunohistochemical stains. Results : AI was found to range from 0 to $1\%$ (median $0.4\%$). Patients with low AI ($AI{\leq}$median) had a much higher distant metastasis rate at diagnosis than patients with high AI. By analysis of prognostic factors for survival, M stage was significant in univariate analysis. AI, chemotherapy, M stage, T stage, and stage were significant in multivariate analysis. The correlation between the AI and p53 mutation was not seen. Conclusion : AI was related with distant metastasis at diagnosis and not with p53 mutation. Also low AI group tended to have shorter survival time than high AI group.

• Biomedical Science Letters
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• v.18 no.3
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• pp.307-309
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• 2012

(S)-(+)-3(3,4-dihydroxy-phenyl)-acrylic acid 2,2-dimethyl-8-oxo3,4-dihydro-2H,8H-pyrano[3,2-g]Chromen-3-yl-ester (Compound 6, C6) is synthesized from (S)-(+)-decursin and attenuates the pathophysiologic progression of asthma in a ovalbumin-induced asthmatic mouse model. In the present study, we examined the effect of C6 on spontaneous apoptosis of eosinophils and neutrophils of normal and asthmatic subjects. C6 increased the apoptosis of asthmatic eosinophils in a dose-dependent manner, but it inhibited neutrophil apoptosis. C6 has no effect on apoptosis of normal eosinophils and neutrophils. LY294002, an inhibitor of PI3K, rottlerin, an inhibitor of $PKC{\delta}$, Ro-31-8425, an inhibitor of classical PKC inhibitor, PD98059, an inhibitor of MEK, and BAY 11-7085, an inhibitor of NF-${\kappa}B$, blocked the inhibitory effect on apoptosis of asthmatic neutrophils due to C6. These results indicate that C6 may be valuable as a therapeutic agent for the treatment of asthma.