• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.4
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• pp.1055-1060
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• 2004

Apoptosis is the ability of cells to self-destruct by the activation of an intrinsic cellular suicide program when the cells are no longer needed or when they are seriously damaged. Morphologically, apoptosis is characterized by the appearance of membrane blebbing, cell shrinkage, chromatin condensation, DNA cleavage, and the fragmentation of the cell membrane-bound apoptotic bodies. Siegesbeckia glabrescens Makino (Siegesbeckiae Herba, SG) has been widely used as treatments for arthritis, and fever, as well as detoxification properties. The present studies were undertaken to evaluate if SG has an anti-apoptotic property. Cell viability was measured by XTT and tryphan blue stain. Morphological characteristic of human aortic smooth muscle cells(HASMC) were visualized with a phase-contrast microscope. SG significantly reduced HASMC, but not human umbilical vein endothelial cell(HUVEC), viability in a dose-dependent manner. Confluent untreated cells at 24hrs showed normal morphology, flat with a uniform polygonal shape. SG-treated cells (0.5㎎/㎖) at 24hrs showed apoptotic morphology. Cells became irregular with elongated lamellipodia, and exhibited condensed chromatin in nuclei with occasional endoucleation. There was an increase in the number of apoptotic cells rounding-up and being detached from the substrate. TUNEL staining of SG-treated cells showed dark-brown stains in nuclei and cytosol. Caspases are central components of the machinery responsible for apoptosis and are generally divided into two categories; the initiator caspases, which include caspases-2,-8,-9, and -10, and the effector caspases, which include caspases-3,-6, and -7. SG decreased anti-caspase-3 protein expression, which means activation of caspases-3 activity. It has been reported that there is a link between NO formation and apoptosis. NO production was accelerated by SG treatment in HASMC. L-NNA, NOS inhibitor, inhibited SG-induced apoptosis. These results, therefore, indicated that both caspases-3 and NO production are involved in apoptosis in smooth muscle cells. According to these results, SG may have a potential effect in the treatment of hypertensive atherosclerosis.

• Journal of Life Science
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• v.25 no.11
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• pp.1235-1243
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• 2015

Hwangheuk-san (HHS) is a Korean multi-herb formula comprising four medicinal herbs. HHS, which was recorded in “Dongeuibogam,” has been used to treat patients with inflammation syndromes and digestive tract cancer for hundreds of years. However, little is known about its anti-tumor efficacy. The present study investigated the pro-apoptotic effect and mode of action of HHS against AGS human gastric carcinoma cells. HHS inhibited the cell growth of AGS cells in a dose-dependent manner, which was associated with the induction of apoptotic cell death, as evidenced by the formation of apoptotic bodies, chromatin condensation, and an accumulation of cells in the sub-G1 phase. HHS-induced apoptotic cell death was associated with the up-regulation of pro-apoptotic Bax protein expression, down-regulation of antiapoptotic Bcl-2 protein, and the release of cytochrome c from mitochondria to the cytosol. The treatment of AGS cells with HHS significantly elevated the generation of reactive oxygen species (ROS). Additionally, apoptosis-inducing concentrations of HHS induced the activation of both caspase-9 and -8, initiator caspases of the mitochondrial-mediated intrinsic and death receptor-mediated extrinsic pathways, respectively, and caspase-3, accompanied by proteolytic degradation of poly (ADP-ribose)-polymerase. However, ROS scavenger and pan-caspases inhibitor significantly blocked HHS-induced growth inhibition and apoptosis. Taken together, these findings suggest that HHS induces apoptosis through ROS- and caspase-dependent mechanisms and that HHS may be a potential chemotherapeutic agent for the control of human gastric cancer.

• Journal of Life Science
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• v.25 no.8
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• pp.849-860
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• 2015

The anti-cancer activities of Rhus verniciflua Stokes (GC), Ulmus davidiana var. japonica Nakai (UGP) and arsenium sublimatum (SS) extracts, which have been used Oriental medicine therapy for various diseases, were investigated. The treatment of GC, UGP and SS alone, and combined treatment with GC, UGP and SS did not affect the cell viability in the mouse normal cell lines (RAW 264.7 macrophages and C2C12 myoblasts). However, co-treatment with GC, UGP and SS markedly induces apoptosis in human gastric cancer AGS cells, but not in other various cancer cell lines (human lung cancer A549, colon cancer HCT116, liver cancer Hep3B and bladder T24 cells) as evidenced by formation of apoptotic bodies, chromatin condensation, and accumulation of annexin-V positive cells. Co-treatment with GC, UGP and SS effectively induced the expression levels of Fas and Fas ligand, and inhibited the levels IAP family proteins such as XIAP, cIAP-1 and survivin, and anti-apoptotic Bcl-xL proteins compared with treatment with either agent alone. Combined treatment also significantly induced the loss of mitochondrial membrane potential, which was associated with the activation of caspases (-3, -8, and -9) and degradation of poly (ADP-ribose) polymerase. However, the cytotoxic effects induced by co-treatment with GC, UGP and SS were significantly attenuated by pan-caspases inhibitor, z-VAD-fmk, indicating an important role for caspases. These results indicated that the caspases were key regulators of apoptosis in response to co-treatment of GC, UGP and SS in human gastric cancer AGS cells and further studies will be needed to identify the active compounds.

• Journal of Microbiology and Biotechnology
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• v.19 no.11
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• pp.1355-1363
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• 2009

In the present study, the neuroprotective effects of astaxanthin on $H_2O_2$-mediated apoptotic cell death, using cultured mouse neural progenitor cells (mNPCs), were investigated. To cause apoptotic cell death, mNPCs were pretreated with astaxanthin for 8 h and followed by treatment of 0.3 mM $H_2O_2$. Pretreatment of mNPCs with astaxanthin significantly inhibited $H_2O_2$-mediated apoptosis and induced cell growth in a dose-dependent manner. In Western blot analysis, astaxanthin-pretreated cells showed the activation of p-Akt, p-MEK, p-ERK, and Bcl-2, and the reduction of p-P38, p-SAPK/JNK, Bax, p-GSK3b, cytochrome c, caspase-3, and PARP. Because $H_2O_2$ triggers caspases activation, this study examined whether astaxanthin can inhibit caspases activation in $H_2O_2$-treated mNPCs. After $H_2O_2$ treatment, caspases activities were prominently increased, but astaxanthin pretreatment significantly inhibited $H_2O_2$-mediated caspases activation. Astaxanthin pretreatment also significantly recovered the ATP production ability of $H_2O_2$-treated cells. These findings indicate that astaxanthin inhibits $H_2O_2$-mediated apoptotic features in mNPCs. Inhibition assays with SB203580 ($10\;{\mu}M$, a specific inhibitor of p38) and PD98059 ($10\;{\mu}M$, a specific inhibitor of MEK) clearly showed that astaxanthin can inhibit $H_2O_2$-mediated apoptotic death via modulation of p38 and MEK signaling pathways.

• BMB Reports
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• v.46 no.12
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• pp.588-593
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• 2013

Apoptosis, programmed cell death, is a process involved in the development and maintenance of cell homeostasis in multicellular organisms. It is typically accompanied by the activation of a class of cysteine proteases called caspases. Apoptotic caspases are classified into the initiator caspases and the executioner caspases, according to the stage of their action in apoptotic processes. Although caspase-3, a typical executioner caspase, has been studied for its mechanism and substrates, little is known of caspase-6, one of the executioner caspases. To understand the biological functions of caspase-6, we performed proteomics analyses, to seek for novel caspase-6 substrates, using recombinant caspase-6 and HepG2 extract. Consequently, 34 different candidate proteins were identified, through 2-dimensional electrophoresis/MALDI-TOF analyses. Of these identified proteins, 8 proteins were validated with in vitro and in vivo cleavage assay. Herein, we report that HAUSP, Kinesin5B, GEP100, SDCCAG3 and PARD3 are novel substrates for caspase-6 during apoptosis.

• BMB Reports
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• v.35 no.1
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• pp.24-27
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• 2002

Apoptotic cell death is an active process mediated by various signaling pathways, which include the caspase cascade and the stress-activated protein kinase pathways. The caspase cascade is activated by two distinct routes: one from cell surface and the other from mitochondria. Activation of the route from cell surface requires the cellular components that include membrane receptors, adaptor proteins such as TRADD and FADD, and caspase-8, while activation of the other from mitochondria requires Apaf-1, caspase-9, and cytosolic cytochrome c. On the other hand, persistent stimulation of the stress-activated protein kinase pathway is also shown to mediate apoptosis in many cell types. Gene-targeting studies with jnk- or jip-null mice, in particular, strongly suggest that this signaling pathway plays a pivotal role in the cellular machinery for apoptosis.

• BMB Reports
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• v.42 no.2
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• pp.96-100
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• 2009

Aromatic (ar)-turmerone from turmeric oil displays anti-tumorigenesis activity that includes inhibited cell proliferation. This study investigated ar-turmerone-mediated apoptotic protein activation in human lymphoma U937 cells. Ar-turmerone treatment inhibited U937 cell viability in a concentration-dependent fashion, with inhibition exceeding 84%. Moreover, the treatment produced nucleosomal DNA fragmentation and the percentage of sub-diploid cells increased in a concentration-dependent manner; both are hallmarks of apoptosis. The apoptotic effect of ar-turmerone was associated with the induction of Bax and p53 proteins, rather than Bcl-2 and p21. Activation of mitochondrial cytochrome c and caspase-3 demonstrated that the activation of caspases accompanied the apoptotic effect of ar-turmerone, which mediated cell death. These results suggest that the apoptotic effect of ar-turmerone on U937 cells may involve caspase-3 activation through the induction of Bax and p53, rather than Bcl-2 and p21.

• BMB Reports
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• v.35 no.1
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• pp.94-105
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• 2002

Apoptotic cell death is a fundamental and highly regulated biological process in which a cell is instructed to actively participate in its own demise. This process of cellular suicide is activated by developmental and environmental cues and normally plays an essential role in eliminating superfluous, damaged, and senescent cells of many tissue types. In recent years, a number of experimental studies have provided evidence of widespread neuronal and glial apoptosis following injury to the central nervous system (CNS). These studies indicate that injury-induced apoptosis can be detected from hours to days following injury and may contribute to neurological dysfunction. Given these findings, understanding the biochemical signaling events controlling apoptosis is a first step towards developing therapeutic agents that target this cell death process. This review will focus on molecular cell death pathways that are responsible for generating the apoptotic phenotype. It will also summarize what is currently known about the apoptotic signals that are activated in the injured CNS, and what potential strategies might be pursued to reduce this cell death process as a means to promote functional recovery.

• Herbal Formula Science
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• v.14 no.2
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• pp.21-32
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• 2006

The purpose of this study was to investigate the effect of Imyosan on apoptosis in human colorectal cancer HCT116 cells. Phellodendron amurense Rupr. and Atratylodes lancea D.C. compose Imyosan. First of all, to study the cytotoxic effect of methanol extract of Imyosan (IMS-MeOH) on HCT116 cells, the cells were treated with various concentrations of IMS-MeOH and then cell viability was determined by XTT reduction method. IMS-MeOH reduced viability of HCT116 cells in a dose and time-dependent manner. To confirm the induction of apoptosis, the c1eavage of poly ADP-ribose polymerase (PARP), a substrate for caspase-3 and a typical sign of apoptosis, and the activation of caspase-3, procaspase-8 and procaspase-9 were examined by western blot analysis. IMS-MeOH decreased procaspase-3, procaspase-8 and procaspase-9 levels in a dose-dependent manner and induced the clevage of PARP. IMS-MeOH triggered the mitochondrial apoptotic signaling by increasing the release of cytochrome c from mitochondria to cytosol. Furthermore, IMS-MeOH also downregulated the anti-apoptotic Bcl-2 and upregulated the pro-apoptotic-Bax. Therefore, these results suggest that IMS-MeOH induced HCT1l6 cell death through the mitochondrial pathway. To explore whether the activities of caspases was required for induction of apoptosis by IMS-MeOH, caspase-3, -8, -9 activity measured by using substrates, respectively. IMS-MeOH increased caspase-3, -8, -9 activity. Co-treatment with inhibitors of caspase-3, -8, -9 and IMS-MeOH significantly blocked IMS-MeOH-triggered apoptosis in HCT1l6 cells. These results suggest that IMS-MeOH induces caspases-mediated apoptosis.

• BMB Reports
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• v.52 no.2
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• pp.119-126
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• 2019

The tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) initiates the extrinsic apoptotic pathway through formation of the death-inducing signaling complex (DISC), followed by activation of effector caspases. TRAIL receptors are composed of death receptors (DR4 and DR5), decoy receptors (DcR1 and DcR2), and osteoprotegerin. Among them, only DRs activate apoptotic signaling by TRAIL. Since the levels of DR expressions are higher in cancer cells than in normal cells, TRAIL selectively activates apoptotic signaling pathway in cancer cells. However, multiple mechanisms, including down-regulation of DR expression and pro-apoptotic proteins, and up-regulation of anti-apoptotic proteins, make cancer cells TRAIL-resistant. Therefore, many researchers have investigated strategies to overcome TRAIL resistance. In this review, we focus on protein regulation in relation to extrinsic apoptotic signaling pathways via ubiquitination. The ubiquitin proteasome system (UPS) is an important process in control of protein degradation and stabilization, and regulates proliferation and apoptosis in cancer cells. The level of ubiquitination of proteins is determined by the balance of E3 ubiquitin ligases and deubiquitinases (DUBs), which determine protein stability. Regulation of the UPS may be an attractive target for enhancement of TRAIL-induced apoptosis. Our review provides insight to increasing sensitivity to TRAIL-mediated apoptosis through control of post-translational protein expression.