• Korean Circulation Journal
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• v.54 no.5
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• pp.233-252
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• 2024

Background and Objectives: Myocardial ischemia-reperfusion injury (MIRI) refers to the damage of cardiac function caused by restoration of blood flow perfusion in ischemic myocardium. However, long non-coding RNA prostate androgen regulated transcript 1 (PART1)'s role in MIRI remain unclear. Methods: Immunofluorescence detected LC3 expression. Intermolecular relationships were verified by dual luciferase reporter assay. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, flow cytometry and transferase-mediated dUTP nick-end labeling (TUNEL) assays analyzed cell viability and apoptosis. The release of lactate dehydrogenase was tested via enzyme-linked immunosorbent assay (ELISA). Left anterior descending coronary artery surgery induced a MIRI mouse model. Infarct area was detected by 2,3,5-triphenyltetrazolium chloride staining. Hematoxylin and eosin staining examined myocardial injury. ELISA evaluated myocardial marker (creatine kinase MB) level. Results: PART1 was decreased in hypoxia/reoxygenation (H/R) induced AC16 cells and MIRI mice. PART1 upregulation attenuated the increased levels of Bax, beclin-1 and the ratio of LC3II/I, and enhanced the decrease of Bcl-2 and p62 expression in H/R-treated cells. PART1 upregulation alleviated H/R-triggered autophagy and apoptosis via miR-302a-3p. Mechanically, PART1 targeted miR-302a-3p to upregulate transcription factor activating enhancer-binding protein 2C (TFAP2C). TFAP2C silencing reversed the protected effects of miR-302a-3p inhibitor on H/R treated AC16 cells. We further established TFAP2C combined to dual-specificity phosphatase 5 (DUSP5) promoter and activated DUSP5. TFAP2C upregulation suppressed H/R-stimulated autophagy and apoptosis through upregulating DUSP5. Overexpressed PART1 reduced myocardial infarction area and attenuated MIRI in mice. Conclusion: PART1 improved the autophagy and apoptosis in H/R-exposed AC16 cells through miR-302a-3p/TFAP2C/DUSP5 axis, which might provide novel targets for MIRI treatment.

• The Korea Journal of Herbology
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• v.21 no.2
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• pp.37-46
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• 2006

Objectives : The purpose of this study was to investigate the effect of Dangguibohyultang (DB) and its combination (DB-I; Astragali membraneus BUNGE : Angelica gigas NAKAI=5:1, DB-II; Astragali membraneus BUNGE:Angelica gigas NAKAI=1:1, DB-III; Astragali membraneus BUNGE:Angelica gigas NAKAI=1:5,) on apoptosis in human colorectal adenocarcinoma HCT116 cells. Methods : To study the cytotoxic effect of methanol extract of DB-I, DB-II and DB-III on HCT116 cells, the cell viability was determined by XTT reduction method and ttypan blue exclusion assay. To confirm the induction of apoptosis, the cleavage of poly ADP-ribose polymerase (PARP), a substrate for caspase-3 and a typical sign of apoptosis, and the activation of procaspase-3, -8 and -9 were examined by western blot analysis. Furthermore, DB-induced apoptosis was confirmed by DNA fragmentation. The release of cytochrome C from mitochondria to cytosol, the level of Bcl-2 and Bax, and the expressions of Raf/MEK/ERK were examined by western blot analysis. Results : DB-I and DB-II reduced proliferation of HCT116 cells in a dose-dependent manner. DB-I and DB-II decreased procaspase-3, -8, -9 levels in a dose-dependent manner and induced the clevage of PARP. DB-I and DB-II also triggered the mitochondrial apoptotic signaling by increasing the release of cytochrome C from mitochondria to cytosol, decreasing of anti-apoptotic Bcl-2, and increasing of pro-apoptotic Bax. DB-I and DB-II decreased the activation of Ras/Raf/MEK/ERK cascade in a dose-dependent manner. Conclusion : These results suggest that DB-I and DB-II induce apoptosis via mitochondrial pathway in HCT116 cells. Furthermore, Raf/MEK/ERK cascade is involved in DB-induced apoptosis. These results suggest that DB is potentially useful as a chemotherapeutic agent in human liver cancer.

• Journal of Life Science
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• v.17 no.8 s.88
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• pp.1053-1062
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• 2007

In the present work, we show that tamoxifen(Tam)-induced cytotoxicity is due to the mitochondrial-dependent pathway triggered by the intracellular $Ca^{2+}$ increase in MCF-7 human breast cancer cells. Tam induced the intracellular $Ca^{2+}$ increase. According to the experimental results with $Ca^{2+}$ channel blockers, Tam-induced $Ca^{2+}$ uptake seemed to depend on the voltage-sensitive $Ca^{2+}$ channel at the early stage, but at later stages the intracellular $Ca^{2+}$ increases are more likely due partly to the release of stored $Ca^{2+}$ and partly to the capacitative $Ca^{2+}$ or other entry pathways. Tam-induced $Ca^{2+}$ increase led to the release of cytochrome c from mitochondria into the cytosol and the change of mitochondrial membrane potential. In MCF-7 cells, caspase-7 plays a key role in the downstream of apoptosis because caspase-3 is absent. In the cells treated with Tam, caspase-7 cleavage was increased almost two-fold. There was no marked alteration in the level of anti-apoptotic Bcl-2 protein; however, the cells showed increased expression of pro-apoptotic Bax protein more than two-fold in response to Tam. These results imply that the apoptotic signaling pathway activated by Tam is likely to be mediated via the mitochondrial-dependent pathway.

• Korean Journal of Clinical Laboratory Science
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• v.52 no.3
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• pp.245-252
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• 2020

Macrophage cell death contributes to the formation of plaque, leading to the development of atherosclerosis. The accumulation of triglyceride (TG) is also associated with the pathogenesis of atherosclerosis. A previous study reported that TG induces the cell death of macrophages. This study examined whether the cytoplasmic release of cathepsin B from lysosome is associated with the TG-induced cell death of macrophage. The release of cathepsin B was increased in the TG-treated THP-1 macrophages, but the TG treatment did not affect cathepsin B expression. Furthermore, the inhibition of cathepsin B by its inhibitor, CA-074 Me, partially inhibited the TG-induced cell death of macrophage. TG-triggered macrophage cell death is mediated by the activation of caspase-1, -2, and apoptotic caspases. Therefore, this study investigated whether cathepsin B is implicated in the activation of these caspases. The inhibition of cathepsin B blocked the activation of caspase-7, -8, and -1 but did not affect the activity of caspase-3, -9, and -2. Overall, these results suggest that TG-induced cytoplasmic cathepsin B causes THP-1 macrophage cell death by activating caspase-1, leading to subsequent activation of the extrinsic apoptotic pathway.

• Journal of Life Science
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• v.29 no.12
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• pp.1393-1400
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• 2019

In the present study, we examined the effect of mitochondrial K⁺ channel opener diazoxide on the mitochondria-dependent apoptotic signaling in endothelial cells exposed to high glucose (HG) media. Endothelial cells derived from human umbilical veins were exposed to HG media containing 30 mM glucose, and the degree of apoptotic cell death associated with activation of the mitochondria-dependent apoptotic signaling pathway was determined. Exposure to HG media was seen to enhance apoptotic cell death in a time-dependent manner. In these cells, activation of caspases 3, 8, and 9 was observed, and while caspase-3 and -9 inhibitors suppressed the HG-induced apoptotic cell death, a caspase-8 inhibitor did not. The HG-treated cells exhibited disruption of mitochondrial membrane potential, formation of permeability transition pores, and cytosolic release of cytochrome c. Subsequently, diazoxide was seen to attenuate the HG-induced apoptotic cell death; caspase-9 activation was suppressed but caspase 8 was not. Diazoxide also suppressed the depolarization of mitochondrial membrane potential, the formation of mitochondrial permeability transition pores, and the release of cytochrome c. These effects were significantly inhibited by 5-hydroxydecanoate, a selective blocker of ATP-sensitive K⁺ channels (K_ATP). The present results demonstrate that diazoxide exhibits a beneficial effect to ameliorate HG-induced endothelial cell apoptosis. Opening the K_ATP could help preserve the functional integrity of mitochondria and provide an underlying mechanism to suppress HG-triggered apoptotic signaling.

• Tuberculosis and Respiratory Diseases
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• v.39 no.6
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• pp.526-535
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• 1992

Background: The oxygen radicals released by alveolar macrophages contribute to killing of microorganisms including M. tuberculosis. Macrophages are "primrd" for enhanced oxygen radical release by macrophage activator like IFN-$\gamma$ and LPS, which do not themselves cause release of oxygen radicals. Actural production of oxygen radicals is "triggered" by phagocytosis or by exposure to chemical stimuli like PMA or FMLP. There has been debates about the priming effect of alveolar macro phages because they are exposed to usual environmental particles unlike blood monocytes. Therefore we examined priming effect of IFN-$\gamma$ in human alveolar macrophages comparing with that in blood monocytes and rat alveolar macrophages. And we observed the alterations of superoxide production in both human and rat alveolar macrophages after exposure to M. tuberculosis H37Ra bacilli itself and its lysate. Methods: Bronchoalveolar lavage fluid was processed to isolate alveolar macrophages by adherence and the adherent cells were removed by cold shock method. After exposure to M. tuberculosis H37Ra strain, alveolar macrophages were incubated for 24 hours with IFN-$\gamma$. The amount of superoxide production stimulated with PMA was measured by ferricytochrome C reduction method. Results: 1) The priming effect in human alveolar macrophages was not observed even with high concentration of IFN-$\gamma$ while it was observed in blood monocytes and rat alveolar macrophages. 2) Both human and rat alveolar macrophages exposed to avirulent H37Ra strain showed triggering of superoxide release and similar results were shown with the exposure to H37Ra lysate. Conclusion: The priming effect in human alveolar macrophages is not observed because of its usual exposure to environmental particles and avirulent H37Ra strain does not inhibit the activation of alveolar macrophages.

• Journal of Life Science
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• v.25 no.9
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• pp.984-992
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• 2015

Sanguinarine is a benzophenanthridine alkaloid originally isolated from the roots of Sanguinaria canadensis. It has multiple biological activities (e.g., antioxidant and antiproliferative) and immune-enhancing potential. In this study, we explored the proapoptotic properties and modes of action of sanguinarine in human hepatocellular carcinoma HepG2 cells. Our results revealed that sanguinarine inhibited HepG2 cell growth and induced apoptosis in a dose-dependent manner. The induction of apoptosis by sanguinarine was associated with the up-regulation of Fas and Bax, the release of cytochrome c from the mitochondria to the cytosol, and the loss of the mitochondrial membrane potential. In addition, sanguinarine activated caspase-9 and -8, initiator caspases of the intrinsic and death extrinsic pathways, respectively, and caspase-3, accompanied by proteolytic degradation of poly (ADP-ribose) polymerase. Sanguinarine also triggered the generation of reactive oxygen species (ROS). The elimination of ROS by N-acetylcysteine reversed sanguinarine-induced apoptosis. Furthermore, sanguinarine induced the dephosphorylation of Akt and the phosphorylation of mitogen-activated protein kinases, including extracellular signal-regulated kinase (ERK), c-jun N-terminal kinase (JNK), and p38. The growth inhibition was enhanced by the combined treatment of sanguinarine with a phosphatidylinositol 3'-kinase (PI3K) inhibitor and an ERK inhibitor but not JNK and p38 inhibitors. Overall, our data indicate that the proapoptotic effects of sanguinarine in HepG2 cells depend on ROS production and the activation of both intrinsic and extrinsic signaling pathways, which is mediated by blocking PI3K/Akt and activating the ERK pathway. Thus, our data suggest that sanguinarine may be a natural compound with potential for use as an antitumor agent in liver cancer.

• Journal of the Korean earth science society
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• v.34 no.6
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• pp.492-506
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• 2013

The historical accounts and materials about the eruption of Mt. Baekdusan as observed by the geological survey is now showing some signs of waking from a long slumber. As a response of the volcanic eruption of Mt. Baekdusan, water release may occur from the stored water in Lake Cheonjii caldera. The volcanic flood is crucial in that it has huge potential energy that can destruct all kinds of man-made structures and that its velocity can reach up to 100 km $hr^{-1}$ to cover hundreds of kilometers of downstream of Lake Cheonji. The ultimate goal of the study is to estimate the level of damage caused by the volcanic flood of Lake Cheon-Ji caldera. As a preliminary study a scenario-based numerical analysis is performed to build hydrographs as a function of time. The analysis is performed for each scenario (breach, magma uplift, combination of uplift and breach, formation of precipitation etc.) and the parameters to require a model structure is chosen on the basis of the historic records of other volcanos. This study only considers the amount of water at the rim site as a function of time for the estimation whereas the downstream routing process is not considered in this study.

• Herbal Formula Science
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• v.15 no.2
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• pp.127-137
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• 2007

The purpose of this study was to investigate the effect of Yong-dam-sa-gan-tang (YST) on apoptosis in HepG2 cells, First of all. to study the cytotoxic effect of methanol extract of YST on HepG2 cells, the cells were treated with various concentrations of YST and then cell viability was determined by XTT reduction method and trypan blue exclusion assay. YST reduced proliferation of HepG2 cells in a dose-dependent manner. To confirm the induction of apoptosis, HepG2 cells were treated with various concentrations of YST. The cleavage of poly AD P-ribose polymerase (P ARP), a substrate for caspase-3 and a typical sign of apoptosis, and the activation of caspase-3, procaspase-8 and procaspase-8 were examined by western blot analysis. YST decreased procaspase-3, procaspase-8 and procaspase-9 levels in a dose-dependent manner and induced the clevage of PARP. YST triggered the mitochondrial apoptotic signaling by increasing the release of cytochrome c from mitochondria to cytosol. Furthermore, YST also downregulated the anti-apoptotic Bcl-2 and upregulated the pro-apoptotic-Bax. Therefore, this result suggest that YST induced HepG2 cell death through the mitochondrial pathway. Sustained activation of the Ras/Raf/MEK/ERK cascade in cells results in a cell cycle arrest and has been implicated in the differentiation of certain cell types, in many cases acting to promote differentiation. YST decreased the activation of Ras/Raf/MEK/ERK cascade in a dose-dependent manner. These results suggest that YST is potentially useful as a chemo-therapeutic agent in HepG2.

• Journal of Life Science
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• v.18 no.9
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• pp.1177-1185
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• 2008

In the present work, we show that spermine (spm)-induced cytotoxicity is due to the mitochondrial-dependent pathway triggered by the intracellular $Ca^{2+}$ increase in MCF-7 human breast cancer cells. Spm induced the intracellular $Ca^{2+}$ increase in a dose-dependent manner in the medium containing 1.5 mM $Ca^{2+}$. Even in the $Ca^{2+}$-free medium, spm could induce a minor $Ca^{2+}$ increase in a dose-dependent fashion, suggesting a probable leak from the internal storage. The cytotoxic effect of $Ca^{2+}$ could be further proved by using either BAPTA or ionophore. Spm-induced $Ca^{2+}$ increase led to the release of cytochrome c from mitochondria into the cytosol and the change of mitochondrial membrane potential. In MCF-7 cells, caspase-7 plays a key role in the downstream of apoptosis because caspase-3 is absent. In the cells treated with spm, the cleavage of caspase-7 and -12 was increased almost two-fold. The level of anti-apoptotic Bcl-2 protein decreased to 35% of the control; however, the cells showed increased expression of pro-apoptotic Bax protein about two-fold in response to spm. These results imply that the apoptotic signaling pathway activated by spm is likely to be mediated via the mitochondrial-dependent pathway.