• Journal of Applied Biological Chemistry
• /
• v.66
• /
• pp.138-143
• /
• 2023

Liver fibrosis is caused by metabolic problems such as cholestasis, genetic problems, or viral infections. Inhibiting hepatic stellate cell (HSC) activation or inducing selective apoptosis of activated HSCs is used as a treatment strategy for liver fibrosis. It has been reported that when HSCs are activated, their apoptosis sensitivity to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is enhanced because the expression of death receptor 5 is elevated. Finding a natural compound that can enhance the apoptotic effect of TRAIL on HSCs is a necessary strategy for liver fibrosis treatment. It was confirmed here that mangosteen-derived gartanin increased the effect of TRAIL-induced apoptosis by increasing the expression of DR5 in a p38-dependent manner in the hepatic stellate cell line LX-2. Combined treatment with gartanin and TRAIL accelerated DNA cleavage through caspase-3 activation and enhanced antifibrotic effects in LX-2 cells.

• BMB Reports
• /
• v.40 no.5
• /
• pp.636-643
• /
• 2007

This study was designed to identify and characterize the mechanism of macrophage activation by AAP, an acidic polysaccharide fraction isolated from the roots of Angelica sinensis (Oliv.) Diels. As a result, AAP significantly enhanced nitric oxide (NO) production and cellular lysosomal enzyme activity in murine peritoneal macrophages in vitro and in vivo. Furthermore, L-NAME, a specific inhibitor of inducible nitric oxide synthase (iNOS), effectively suppressed AAP-induced NO generation in macrophages, indicating that AAP stimulated macrophages to produce NO through the induction of iNOS gene expression and the result was further confirmed by the experiment of the increase of AAP-induced iNOS transcription in a dose-dependent manner. To further investigate, AAP was shown to strongly augment toll-like receptor 4 (TLR4) mRNA expression and the pretreatment of macrophages with anti-TLR4 antibody significantly blocked AAP-induced NO release and the increase of iNOS activity, and tumor necrosis factor-$\alpha$ (TNF-$\alpha$) secretion.

• Biomolecules & Therapeutics
• /
• v.18 no.3
• /
• pp.262-270
• /
• 2010

CD95 receptor is a member of tumor necrosis factor receptor family that mediates apoptosis in many cell types when bound by CD95 ligand or cross-linked by agonistic anti-CD95 antibodies. To determine the role of neutral sphingomyelinase (nSMase) on CD95-mediatd apoptosis, human Jurkat T lymphocytes were exposed to recombinant human CD95 ligand. Treatment with CD95 ligand induced cell death in a concentration and time-dependent manner. CD95-induced cell death was suppressed by inhibitors of SMase such as AY9944 or desipramine. Transfection with human nSMase1 siRNA plasmid into CD95 ligand-treated cells significantly prevented CD95-mediated cell death. CD95-mediated elevation of intracellular ceramide level detected by FACS analysis with anti-ceramide antibody was also decreased by nSMase1 siRNA. Knock-down of nSMase1 expression also blocked cytochrome c release into cytosol and caspase-3 cleavage in CD95-treated cells. Taken together, these results suggest that nSMase1 may play an important role in CD95-mediated apoptotic cell death in Jurkat T cells.

• Herbal Formula Science
• /
• v.25 no.2
• /
• pp.145-154
• /
• 2017

Objectives : Bufalin is one of the bioactive component of 'Sum Su (蟾酥)', which is obtained from the skin and parotid venom gland of toad. Bufalin has been known to possess the inhibitory effects on cell proliferation and inducing apoptosis in various cancer cells. The tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) has concerned, because it can selectively induce apoptotic cell death in many types of malignant cells, while it is relatively non-toxic to normal cells. Here, we investigated whether bufalin can trigger TRAIL-induced apoptotic cell death in EJ human bladder cancer cells. Methods : Effects on the cell viability and apoptotic activity were quantified using MTT assay and flow cytometry analysis, respectively. To investigate the morphological change of nucleus, DAPI staining was performed. Protein expressions were measured by immunoblotting. Results : A combined treatment with bufalin (10 nM) and TRAIL (50 ng/ml) significantly promoted TRAIL-mediated growth inhibition and apoptosis in EJ cells. The apoptotic effects were associated with the up-regulation of death receptor proteins, and the down-regulation of cFLIP and XIAP. Moreover, our data showed that bufalin and TRAIL combination activated caspases and subsequently increased degradation of poly(ADP-ribose) polymerase. Conclusions : Taken altogether, the nontoxic doses of bufalin sensitized TRAIL-mediated apoptosis in EJ cells. Therefore, bufalin might be an effective therapeutic strategy for the safe treatment of TRAIL-resistant bladder cancers.

• Bulletin of the Korean Chemical Society
• /
• v.34 no.4
• /
• pp.1089-1095
• /
• 2013

The tumor necrosis factor-receptor 1 (TNFR1)-associated death domain protein (TRADD) contains an N-terminal TRAF binding domain and a C-terminal death domain. TRADD is known to interact directly with TNF receptor 2 (TNFR2) and the Fas-associated death domain protein (FADD), which are signal transducers that activate NF-${\kappa}B$ and induce apoptosis, respectively. To date, there has been no structural information on the TRADD and FADD death domain (DDs) complex. In this study, the death domains of TRADD and FADD were co-expressed and purified from Escherichia coli for structural characterization. We found that human TRADD (hTRADD) interacted strongly with mouse FADD (mFADD) via their DDs and interacted weakly with human FADD (hFADD)-DD. Moreover, the structures of the TRADD-DD:FADD-DD complexes were separately modeled from predicted structures in the protein data bank (PDB). The results of this study will have important applications in human diseases such as cancer, AIDS, degenerative and autoimmune diseases, and infectious diseases.

• The Korean Journal of Food And Nutrition
• /
• v.34 no.5
• /
• pp.441-448
• /
• 2021

This study was designed to investigate the intracellular signaling pathways and immunoenhancing effect of macrophage activation by crude polysaccharides (CPP) extracted from citrus peels. CPP did not affect the cytotoxicity of RAW264.7 cells, but showed dose-dependent effects on cell viability. Also, CPP showed high production of chemokine (nitric oxide (NO)) and cytokines (interleukin (IL)-6 and tumor necrosis factor (TNF)-α). CPP increased IL-6, TNF-α, and inducible nitric oxide synthase (iNOS) mRNA expression dose-dependently. CPP also strongly induced the phosphorylation of the ERK, p38, and IκBα pathways in RAW 264.7 cells. In anti-pattern recognition receptors (PRRs) experiments, the effect of CPP on NO production was strongly suppressed by neutralizing toll-like receptor (TLR)2, TLR4, and Dectin1 antibodies, whereas IL-6 and TNF-α production by CPP was mainly suppressed by mannose receptor (MR). Therefore, these results suggest that CPP treatment-induced NO production was regulated by the ERK, p38, and NF-κB pathways through TLR2, TLR4, and Dectin1 receptors, whereas IL-6 and TNF-α production was primarily regulated by the ERK, p38, and NF-κB pathways through MR receptors.

• Journal of Ginseng Research
• /
• v.48 no.1
• /
• pp.12-19
• /
• 2024

Skeletal muscle (SM) is the largest organ of the body and is largely responsible for the metabolism required to maintain body functions. Furthermore, the maintenance of SM is dependent on the activation of muscle satellite (stem) cells (MSCs) and the subsequent proliferation and fusion of differentiating myoblasts into mature myofibers (myogenesis). Natural compounds are being used as therapeutic options to promote SM regeneration during aging, muscle atrophy, sarcopenia, cachexia, or obesity. In particular, ginseng-derived compounds have been utilized in these contexts, though ginsenoside Rg1 is mostly used for SM mass management. These compounds primarily function by activating the Akt/mTOR signaling pathway, upregulating myogenin and MyoD to induce muscle hypertrophy, downregulating atrophic factors (atrogin1, muscle ring-finger protein-1, myostatin, and mitochondrial reactive oxygen species production), and suppressing the expressions of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in cachexia. Ginsenoside compounds are also used for obesity management, and their anti-obesity effects are attributed to peroxisome proliferator activated receptor gamma (PPARγ) inhibition, AMPK activation, glucose transporter type 4 (GLUT4) translocation, and increased phosphorylations of insulin resistance (IR), insulin receptor substrate-1 (IRS-1), and Akt. This review was undertaken to provide an overview of the use of ginseng-related compounds for the management of SM-related disorders.

• Journal of Applied Biological Chemistry
• /
• v.66
• /
• pp.186-196
• /
• 2023

Dyglomera^® is an aqueous ethanol extract derived from the fruit and pods of Dichrostachys glomerata. A previous study has revealed that Dyglomera regulates adipogenesis and lipolysis by modulating AMP-activated protein kinase (AMPK) phosphorylation and increased expression levels of lipolysis-related proteins in white adipose tissue of high fat diet-induced mice and 3T3-L1 adipocyte cells. To further investigate mechanisms of Dyglomera, additional studies were performed using 3T3-L1 cells. Results revealed that Dyglomera downregulated adipogenesis by inhibiting the protein kinase B/mammalian target of rapamycin signaling pathway and reconfirmed that it downregulated gene expression levels of proliferator-activated receptor (PPAR)-γ, CCAAT enhancer binding protein α, sterol-regulation element-binding protein-1c. Dyglomera also reduced adipokines such as tumor necrosis factor alpha, interleukin-1β, and interleukin 6 by regulating leptin expression. Moreover, Dyglomera promoted beige-and-brown adipocyte-related phenotypes and regulated metabolism by increasing mitochondrial number and expression levels of genes such as T-box protein 1, transmembrane protein 26, PR domain 16, and cluster of differentiation 40 as well as thermogenic factors such as uncoupling protein 1, proliferator-activated receptor-gamma co-activator-1α, Sirtuin 1, and PPARα through AMPK activation. Thus, Dyglomera not only can inhibit adipogenesis, but also can promote lipolysis and thermogenesis and regulate metabolism by affecting adipokine secretion from 3T3-L1 adipocytes.

• Molecular & Cellular Toxicology
• /
• v.5 no.3
• /
• pp.187-192
• /
• 2009

Toll-like receptors (TLRs) play an important role in host defense by sensing invading microbial pathogens. The stimulation of TLRs by microbial components triggers the activation of the myeloid differential factor 88 (MyD88)- and toll-interleukin-1 receptor domain-containing adapter inducing interferon-$\beta$ (TRIF)-dependent downstream signaling pathways. TLR/MyD88 signaling pathway induces the activation of nuclear factor-kappa B (NF-${\kappa}B$) and the expression of inflammatory cytokine genes, including tumor necrosis factor-alpha, interleukin (IL)-6, IL-12, and IL-$1{\beta}$. On the other hand, TLR/TRIF signaling pathway induces the delayed-activation of NF-${\kappa}B$ and interferon regulatory factor 3 (IRF3), and the expression of type I interferons (IFNs) and IFN-inducible genes. The divalent heavy metal cadmium (Cd) is clearly toxic to most mammalian organ systems, especially the immune system. Yet, the underlying toxic mechanism(s) remain unclear. Cd inhibits the MyD88-dependent pathway by ceasing the activity of inhibitor-${\kappa}B$ kinase. However, it is not known whether Cd inhibits the TRIF-dependent pathway. Presently, Cd inhibited NF-${\kappa}B$ and IRF3 activation induced by lipopolysaccharide (LPS) and polyinosinic-polycytidylic acid. Cd inhibited LPS-induced IRF3 phosphorylation and IFN-inducible genes such as interferon inducible protein-10 and regulated on activation normal T-cell expressed and secreted (RANTES). These results suggest that Cd can modulate TRIF-dependent signaling pathways of TLRs.

• Asian-Australasian Journal of Animal Sciences
• /
• v.29 no.1
• /
• pp.134-141
• /
• 2016

To investigate the role of polysaccharide from Acanthopanax senticosus (ASPS) in preventing lipopolysaccharide (LPS)-induced intestinal injury, 18 mice (at 5 wk of age) were assigned to three groups with 6 replicates of one mouse each. Mice were administrated by oral gavage with or without ASPS (300 mg/kg body weight) for 14 days and were injected with saline or LPS at 15 days. Intestinal samples were collected at 4 h post-challenge. The results showed that ASPS ameliorated LPS-induced deterioration of digestive ability of LPS-challenged mice, indicated by an increase in intestinal lactase activity (45%, p<0.05), and the intestinal morphology, as proved by improved villus height (20.84%, p<0.05) and villus height:crypt depth ratio (42%, p<0.05), and lower crypt depth in jejunum (15.55%, p<0.05), as well as enhanced intestinal tight junction proteins expression involving occludin-1 (71.43%, p<0.05). ASPS also prevented intestinal inflammation response, supported by decrease in intestinal inflammatory mediators including tumor necrosis factor ${\alpha}$ (22.28%, p<0.05) and heat shock protein (HSP70) (77.42%, p<0.05). In addition, intestinal mucus layers were also improved by ASPS, as indicated by the increase in number of goblet cells (24.89%, p<0.05) and intestinal trefoil peptide (17.75%, p<0.05). Finally, ASPS facilitated mRNA expression of epidermal growth factor (100%, p<0.05) and its receptor (200%, p<0.05) gene. These results indicate that ASPS can prevent intestinal mucosal barrier injury under inflammatory conditions, which may be associated with up-regulating gene mRNA expression of epidermal growth factor and its receptor.