• Journal of Ginseng Research
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• 제44권2호
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• pp.258-266
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• 2020

Background: Oxidative stress-induced cardiomyocytes apoptosis is a key pathological process in ischemic heart disease. Glutathione reductase (GR) reduces glutathione disulfide to glutathione (GSH) to alleviate oxidative stress. Ginsenoside Rb1 (GRb1) prevents the apoptosis of cardiomyocytes; however, the role of GR in this process is unclear. Therefore, the effects of GRb1 on GR were investigated in this study. Methods: The antiapoptotic effects of GRb1 were evaluated in H9C2 cells by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, annexin V/propidium iodide staining, and Western blotting. The antioxidative effects were measured by a reactive oxygen species assay, and GSH levels and GR activity were examined in the presence and absence of the GR inhibitor 1,3-bis-(2-chloroethyl)-1-nitrosourea. Molecular docking and molecular dynamics simulations were used to investigate the binding of GRb1 to GR. The direct influence of GRb1 on GR was confirmed by recombinant human GR protein. Results: GRb1 pretreatment caused dose-dependent inhibition of tert-butyl hydroperoxide-induced cell apoptosis, at a level comparable to that of the positive control N-acetyl-L-cysteine. The binding energy between GRb1 and GR was positive (-6.426 kcal/mol), and the binding was stable. GRb1 significantl reduced reactive oxygen species production and increased GSH level and GR activity without altering GR protein expression in H9C2 cells. Moreover, GRb1 enhanced the recombinant human GR protein activity in vitro, with a half-maximal effective concentration of ≈2.317 μM. Conversely, 1,3-bis-(2-chloroethyl)-1-nitrosourea co-treatment significantly abolished the GRb1's apoptotic and antioxidative effects of GRb1 in H9C2 cells. Conclusion: GRb1 is a potential natural GR agonist that protects against oxidative stress-induced apoptosis of H9C2 cells.

• Biomolecules & Therapeutics
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• 제22권6호
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• pp.510-518
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• 2014

Chronic (>24 h) exposure of arsenite, an environmental toxicant, has shown the decreased nitric oxide (NO) production in endothelial cells (EC) by decreasing endothelial NO synthase (eNOS) expression and/or its phosphorylation at serine 1179 ($eNOS-Ser^{1179}$ in bovine sequence), which is associated with increased risk of vascular diseases. Here, we investigated the acute (<24 h) effect of arsenite on NO production using bovine aortic EC (BAEC). Arsenite acutely increased the phosphorylation of $eNOS-Thr^{497}$, but not of $eNOS-Ser^{116}$ or $eNOS-Ser^{1179}$, which was accompanied by decreased NO production. The level of eNOS expression was unaltered under this condition. Treatment with arsenite also induced reactive oxygen species (ROS) production, and pretreatment with a ROS scavenger N-acetyl-L-cysteine (NAC) completely reversed the observed effect of arsenite on $eNOS-Thr^{497}$ phosphorylation. Although protein kinase C (PKC) and protein phosphatase 1 (PP1) were reported to be involved in $eNOS-Thr^{497}$ phosphorylation, treatment with PKC inhibitor, Ro318425, and overexpression of various PKC isoforms did not affect the arsenite-stimulated $eNOS-Thr^{497}$ phosphorylation. In contrast, treatment with PP1 inhibitor, calyculin A, mimicked the observed effect of arsenite on $eNOS-Thr^{497}$ phosphorylation. Lastly, we found decreased cellular PP1 activity in arsenite-treated cells, which was reversed by NAC. Overall, our study demonstrates firstly that arsenite acutely decreases NO production at least in part by increasing $eNOS-Thr^{497}$ phosphorylation via ROS-PP1 signaling pathway, which provide the molecular mechanism underlying arsenite-induced increase in vascular disease.

• Biomolecules & Therapeutics
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• 제28권5호
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• pp.443-455
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• 2020

The thioredoxin (Trx) system plays critical roles in regulating intracellular redox levels and defending organisms against oxidative stress. Recent studies indicated that Trx reductase (TrxR) was overexpressed in various types of human cancer cells indicating that the Trx-TrxR system may be a potential target for anti-cancer drug development. This study investigated the synergistic effect of auranofin, a TrxR-specific inhibitor, on sulforaphane-mediated apoptotic cell death using Hep3B cells. The results showed that sulforaphane significantly enhanced auranofin-induced apoptosis by inhibiting TrxR activity and cell proliferation compared to either single treatment. The synergistic effect of sulforaphane and auranofin on apoptosis was evidenced by an increased annexin-V-positive cells and Sub-G1 cells. The induction of apoptosis by the combined treatment caused the loss of mitochondrial membrane potential (ΔΨm) and upregulation of Bax. In addition, the proteolytic activities of caspases (-3, -8, and -9) and the degradation of poly (ADP-ribose) polymerase, a substrate protein of activated caspase-3, were also higher in the combined treatment. Moreover, combined treatment induced excessive generation of reactive oxygen species (ROS). However, treatment with N-acetyl-L-cysteine, a ROS scavenger, reduced combined treatment-induced ROS production and apoptosis. Thereby, these results deduce that ROS played a pivotal role in apoptosis induced by auranofin and sulforaphane. Furthermore, apoptosis induced by auranofin and sulforaphane was significantly increased through inhibition of the phosphoinositide 3-kinase (PI3K)/Akt pathway. Taken together, the present study demonstrated that down-regulation of TrxR activity contributed to the synergistic effect of auranofin and sulforaphane on apoptosis through ROS production and inhibition of PI3K/Akt signaling pathway.

• 한국환경보건학회지
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• 제49권6호
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• pp.344-352
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• 2023

Background: With its developed port and related industries, the concentration of fine dust is high in Busan compared to other cities in South Korea. Many studies have reported the health effects of fine dust, but there has been a lack of information regarding concentrations of volatile organic compounds among those who exposed to high levels of fine dust. Objectives: This study aimed to define an area with high concentrations of particulate matter and perform biomonitoring surveys among the residents of the area. Methods: Air quality data was collected and the mean level of each district in Busan was derived. We then defined the area with the highest concentrations of PM₁₀ as a target site. Urine samples were collected from the 400 participants and analyzed for VOCs metabolites - trans,trans-Muconic Acid (t,t-MA) and N-AcetylS-(benzyl)-L-cysteine (BMA). Interviews were conducted by trained investigators to examine demographic information. The levels of t,t-MA and BMA were compared with representative South Korean population data (Korean National Environmental Health Survey). The association of the VOC metabolites and fine dust were analyzed by general linear regression analysis. Results: The mean of PM₁₀ in the target site was 42.50 ㎍/m³ from 2018 to 2020. Among the 400 participants in the target site, 74.8% were female and the average age of the participants was 66 years. The geometric mean of t,t-MA was 71.15 ㎍/g creatinine and the BMA was 7.00 ㎍/g creatinine among the residents. The levels were higher than the geometric mean from the 4th KoNEHS. The levels of t,t-MA showed significance in BMI, smoking status, and household income. BMA showed significance in gender and age. Conclusions: Compared to the general population of South Korea, the target site's residents had higher biomonitoring levels. Based on this study, continuous screening for high risk areas, including the target site, and biomonitoring of the residents are required.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제29권5호
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• pp.272-281
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• 2003

본 연구에서는 두경부암 HN-4 세포에서 cancer chemopreventive agent인 curcumin과 resveratrol를 처리하여 HN-4 세포의 생육 억제의 원인이 apoptotic cell death에 의하여 일어나며 세포 주기 조절 단백질의 발현 및 암 전이에 관련된 MMP 활성 저해 기전에 대하여 이해하고자 하였다. HN-4 세포에 다양한 농도(10-100 ${\mu}M$) curcumin을 처리하여 세포주기 조절 단백질의 발현을 측정한 결과 cdk1과 cdk4 단백질이 농도 의존적으로 발현이 감소하였으며, resveratrol 처리에서는 cyclin A 단백질의 특이적인 감소 현상을 확인하였다. Curcumin에 의한 apoptosis 유도 기전을 조사한 결과 anti-apoptotic 기능이 있는 Bcl-2 및 Bcl-xL 단백질 발현 감소 현상은 없었으나, caspase 저해 IAP family 단백질중 cIAP1과 survivin 단백질 발현 현상이 처리 농도 의존적으로 감소하였다. Resveratrol을 처리한 경우 Bcl-2 및 survivin 단백질 발현 감소현상을 확인하였다. Curcumin과 resveratrol에 의한 apoptosis 과정은 caspase-3 의존적인 apoptosis 유도 기전을 보였다. Curcumin에 의한 apoptosis 과정은 항산화제인 NAC 처리에 의해서 저해되었다. Curcumin과 NAC 동시 처리는 cytochrome c 유리, caspase-3 활성화 및 Bax 단백질 분절 현상을 억제하였다. 그러나 resveratrol에 의한 apoptosis 과정은 NAC 처리에 의하여 억제되지 않았다. Curcumin과 resveratrol에 의한 암 전이 관련 단백질인 MMP2와 9의 활성 저해효과도 확인하였다. 결론적으로, curcumin에 의한 항암효과는 세포주기 조절 및 apoptosis 유도 및 전이 관련 단백질의 활성 억제를 통하여 야기되는 것으로 생각되어 진다.

• 생명과학회지
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• 제32권4호
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• pp.310-317
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• 2022

최근 인체에 유해한 요인으로 대기오염의 주성분인 미세먼지에 대한 관심이 증가하고 있다. 특히 직경이 2.5 ㎛ 미만인 PM_2.5는 인간의 폐 상피세포에서 자가포식을 동반한 산화적 스트레스를 유발하는 것으로 알려져 있다. 그러나 PM_2.5가 산화적 스트레스 하에서 자가포식을 증가시키는지와 이 과정이 ROS 의존적인지에 대한 연구는 충분하지 않은 실정이다. 본 연구에서는 PM_2.5가 인간 폐 상피 A594 세포에서 ROS 생성을 통해 자가포식을 촉진하는지를 조사하였다. 우리의 결과에 의하면, PM_2.5와 H₂O₂를 함께 처리한 세포에서는 각각이 단독 처리된 세포에 비하여 세포 생존력이 유의적으로 감소하였으며, 이는 전체 및 미토콘드리아 ROS 생성의 증가와 관련이 있었다. 또한, PM_2.5와 H₂O₂의 동시 처리는 Cyto-ID 염색을 통해 확인된 바와 같이 자가포식 유도의 증가와 LC3, p62 및 beclin 1과 같은 자가포식 바이오 마커 단백질의 발현을 증가시켰다. 그러나 NAC의 전처리에 의하여 ROS의 생성을 인위적으로 차단하였을 경우, PM_2.5와 H₂O₂의 동시 처리에 의한 세포 생존율의 감소와 자가포식 유도는 현저하게 억제되었다. 따라서, PM_2.5에 의해 유도된 ROS 생성이 A549 세포에서 자가포식 유도에 중요한 역할을 할 것으로 추측되며, 이는 PM_2.5에 의해 유도될 수 있는 폐 기능 손상이 산화적 스트레스 하에서 더욱 증가할 수 있음을 의미한다.