• Experimental and Molecular Medicine
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• 제50권11호
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• pp.7.1-7.12
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• 2018

Recent findings from The Cancer Genome Atlas project have provided a comprehensive map of genomic alterations that occur in hepatocellular carcinoma (HCC), including unexpected mutations in apolipoprotein B (APOB). We aimed to determine the clinical significance of this non-oncogenetic mutation in HCC. An Apob gene signature was derived from genes that differed between control mice and mice treated with siRNA specific for Apob (1.5-fold difference; P < 0.005). Human gene expression data were collected from four independent HCC cohorts (n = 941). A prediction model was constructed using Bayesian compound covariate prediction, and the robustness of the APOB gene signature was validated in HCC cohorts. The correlation of the APOB signature with previously validated gene signatures was performed, and network analysis was conducted using ingenuity pathway analysis. APOB inactivation was associated with poor prognosis when the APOB gene signature was applied in all human HCC cohorts. Poor prognosis with APOB inactivation was consistently observed through cross-validation with previously reported gene signatures (NCIP A, HS, high-recurrence SNUR, and high RS subtypes). Knowledge-based gene network analysis using genes that differed between low-APOB and high-APOB groups in all four cohorts revealed that low-APOB activity was associated with upregulation of oncogenic and metastatic regulators, such as HGF, MTIF, ERBB2, FOXM1, and CD44, and inhibition of tumor suppressors, such as TP53 and PTEN. In conclusion, APOB inactivation is associated with poor outcome in patients with HCC, and APOB may play a role in regulating multiple genes involved in HCC development.

• Biomolecules & Therapeutics
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• 제27권6호
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• pp.591-602
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• 2019

Human breast cancer cell line, MDA-MB-231, is highly invasive and aggressive, compared to less invasive cell line, MCF-7. To explore the genes that might influence the malignancy of MDA-MB-231, DNA microarray analysis was performed. The results showed that G0/G1 switch 2 (G0S2) was one of the most highly expressed genes among the genes upregulated in MDA-MB-231. Although G0S2 acts as a direct inhibitor of adipose triglyceride lipase, action of G0S2 in cancer progression is not yet understood. To investigate whether G0S2 affects invasiveness of MDA-MB-231 cells, G0S2 expression was inhibited using siRNA, which led to decreased cell proliferation, migration, and invasion of MDA-MB-231 cells. Consequently, G0S2 inhibition inactivated integrin-regulated FAK-Src signaling, which promoted Hippo signaling and inactivated ERK1/2 signaling. In addition, G0S2 downregulation decreased ${\beta}$-catenin expression, while E-cadherin expression was increased. It was demonstrated for the first time that G0S2 mediates the Hippo pathway and induces epithelial to mesenchymal transition (EMT). Taken together, our results suggest that G0S2 is a major factor contributing to cell survival and metastasis of MDA-MB-231 cells.

• Parasites, Hosts and Diseases
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• 제57권5호
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• pp.461-467
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• 2019

Avian trematodes, Urogonimus turdi (Digenea: Leucochloridiidae), were collected from the intestine of wild birds, Zoothera aurea, 2013-2017 in the Daejeon Metropolitan City, Korea. The body was ellipsoidal, attenuated and/or round ends, 1,987-2,120 long and $819-831{\mu}m$ wide. The oral sucker was subterminal, rounded anteriorly, and $308-425{\times}351-432{\mu}m$ in size; the prepharynx and esophagus were almost lacking; pharynx was well-developed, $142-179{\times}78-170{\mu}m$ in size; intestine narrow, bifurcating just after pharynx, ascending to the oral sucker before looping posteriorly and terminating near the posterior end; ventral sucker larger, in almost median, $536-673{\times}447-605{\mu}m$ and approximately 1.5 times larger than oral sucker. A phylogenetic tree constructed with 18S ribosomal RNA showed inter- and intraspecific relationships. Based on these morphological and molecular findings, we report here a U. turdi from White's thrushes in Korea.

• Journal of Ginseng Research
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• 제37권4호
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• pp.442-450
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• 2013

The aim of this study was to determine and compare the preventive effect of Korean White Ginseng and Red Ginseng on oxidative stress in $H_2O_2$-treated HepG2 cells. The roots of ginseng were extracted with 70% methanol and partitioned with butanol to obtain saponin fractions, which have been known as bioactive constituents of ginseng. 2',7'-Dichlorofluorescein diacetate (DCF-DA) assay and malondialdehyde (MDA) content were measured for evaluating intracellular reactive oxygen species (ROS) generation. Also, mRNA expressions and activities of antioxidant enzymes were analyzed to determine the antioxidant activity of saponin or non-saponin fractions of ginsengs. According to DCF-DA assay, $H_2O_2$-induced MDA release and ROS generation were significantly reduced by treatment with saponin fractions of white and red ginseng roots. Also, saponin fractions increased effectively intracellular antioxidant enzyme activities including catalase, glutathione peroxidase and superoxide dismutase in $H_2O_2$-treated HepG2 hepatoma cells. In general, red ginseng was more effective than white ginseng for reducing oxidative stress. These results indicate that administration of red ginseng may certainly contribute relatively stronger than white ginseng to prevent from damaging liver function by oxidative stress.

• Molecules and Cells
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• 제42권11호
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• pp.810-819
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• 2019

For physiological or pathological understanding of bone disease caused by abnormal behavior of osteoclasts (OCs), functional studies of molecules that regulate the generation and action of OCs are required. In a microarray approach, we found the suppression of tumorigenicity 5 (ST5) gene is upregulated by receptor activator of nuclear $factor-{\kappa}B$ ligand (RANKL), the OC differentiation factor. Although the roles of ST5 in cancer and ${\beta}-cells$ have been reported, the function of ST5 in bone cells has not yet been investigated. Knockdown of ST5 by siRNA reduced OC differentiation from primary precursors. Moreover, ST5 downregulation decreased expression of NFATc1, a key transcription factor for osteoclastogenesis. In contrast, overexpression of ST5 resulted in the opposite phenotype of ST5 knockdown. In immunocytochemistry experiments, the ST5 protein is colocalized with Src in RANKL-committed cells. In addition, ST5 enhanced activation of Src and Syk, a Src substrate, in response to RANKL. ST5 reduction caused a decrease in RANKL-evoked calcium oscillation and inhibited translocation of NFATc1 into the nucleus. Taken together, these findings provide the first evidence of ST5 involvement in positive regulation of osteoclastogenesis via Src/Syk/calcium signaling.

• Biomolecules & Therapeutics
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• 제27권3호
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• pp.290-301
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• 2019

Paeonol has neuroprotective function, which could be useful for improving central nervous system disorder. The purpose of this study was to characterize the functional mechanism involved in brain transport of paeonol through blood-brain barrier (BBB). Brain transport of paeonol was characterized by internal carotid artery perfusion (ICAP), carotid artery single injection technique (brain uptake index, BUI) and intravenous (IV) injection technique in vivo. The transport mechanism of paeonol was examined using conditionally immortalized rat brain capillary endothelial cell line (TR-BBB) as an in vitro model of BBB. Brain volume of distribution (VD) of [$^3H$]paeonol in rat brain was about 6-fold higher than that of [$^{14}C$]sucrose, the vascular space marker of BBB. The uptake of [$^3H$]paeonol was concentration-dependent. Brain volume of distribution of paeonol and BUI as in vivo and inhibition of analog as in vitro studies presented significant reduction effect in the presence of unlabeled lipophilic compounds such as paeonol, imperatorin, diphenhydramine, pyrilamine, tramadol and ALC during the uptake of [$^3H$]paeonol. In addition, the uptake significantly decreased and increased at the acidic and alkaline pH in both extracellular and intracellular study, respectively. In the presence of metabolic inhibitor, the uptake reduced significantly but not affected by sodium free or membrane potential disruption. Similarly, paeonol uptake was not affected on OCTN2 or rPMAT siRNA transfection BBB cells. Interestingly. Paeonol is actively transported from the blood to brain across the BBB by a carrier mediated transporter system.

• 한국동물생명공학회지
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• 제34권1호
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• pp.2-9
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• 2019

Because mesenchymal stem cells (MSCs) maintain distinct capacities with respect to self-renewal, differentiation ability and immunomodulatory function, they have been highly considered as the therapeutic agents for cell-based clinical application. Of particular, differentiation condition alters characteristics of MSCs, including cellular morphology, expression of gene/protein and cell surface molecule, immunological property and apoptosis. However, the previous results for differentiation-related apoptosis in MSCs have still remained controversial due to varied outcomes. Therefore, the present study aimed to disclose periodical alterations of pro- and anti-apoptosis in MSCs under differentiation inductions. The human dental pulp-derived MSCs (DP-MSCs) were differentiated into adipocytes and osteoblasts during early (1 week), middle (2 weeks) and late (3 weeks) stages, and were investigated on their apoptosis-related changes by Annexin V assay, qRT-PCR and western blotting. The ratio of apoptotic cell population was significantly (p < 0.05) elevated during the early to middle stages of differentiations but recovered up to the similar level of undifferentiated state at the late stage of differentiation. In the expression of mRNA and protein, whereas expressions of pro-apoptosis-related makers (BAX and BAK) were not altered in any kind and duration of differentiation inductions, anti-apoptosis marker (BCL2) was significantly (p < 0.05) elevated even at the early stage of differentiations. The recovery of apoptotic cell population at the late stage of differentiation is expected to be associated with the response by elevation of anti-apoptotic molecules. The present study may contribute on understanding for cellular mechanism in differentiation of MSCs and provide background data in clinical application of MSCs in the animal biotechnology to develop effective and safe therapeutic strategy.

• Biomolecules & Therapeutics
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• 제29권6호
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• pp.615-629
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• 2021

An active compound, triterpene saponin, astersaponin I (AKNS-2) was isolated from Aster koraiensis Nakai (AKNS) and the autophagy activation and neuroprotective effect was investigated on in vitro and in vivo Parkinson's disease (PD) models. The autophagy-regulating effect of AKNS-2 was monitored by analyzing the expression of autophagy-related protein markers in SH-SY5Y cells using Western blot and fluorescent protein quenching assays. The neuroprotection of AKNS-2 was tested by using a 1-methyl-4-phenyl-2,3-dihydropyridium ion (MPP⁺)-induced in vitro PD model in SH-SY5Y cells and an MPTP-induced in vivo PD model in mice. The compound-treated SH-SY5Y cells not only showed enhanced microtubule-associated protein 1A/1B-light chain 3-II (LC3-II) and decreased sequestosome 1 (p62) expression but also showed increased phosphorylated extracellular signal-regulated kinases (p-Erk), phosphorylated AMP-activated protein kinase (p-AMPK) and phosphorylated unc-51-like kinase (p-ULK) and decreased phosphorylated mammalian target of rapamycin (p-mTOR) expression. AKNS-2-activated autophagy could be inhibited by the Erk inhibitor U0126 and by AMPK siRNA. In the MPP⁺-induced in vitro PD model, AKNS-2 reversed the reduced cell viability and tyrosine hydroxylase (TH) levels and reduced the induced α-synuclein level. In an MPTP-induced in vivo PD model, AKNS-2 improved mice behavioral performance, and it restored dopamine synthesis and TH and α-synuclein expression in mouse brain tissues. Consistently, AKNS-2 also modulated the expressions of autophagy related markers in mouse brain tissue. Thus, AKNS-2 upregulates autophagy by activating the Erk/mTOR and AMPK/mTOR pathways. AKNS-2 exerts its neuroprotective effect through autophagy activation and may serve as a potential candidate for PD therapy.

• Biomolecules & Therapeutics
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• 제29권2호
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• pp.195-204
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• 2021

Cereblon (CRBN), a substrate receptor of cullin 4-RING E3 ligase (CRL4) regulates the ubiquitination and degradation of c-Jun, mediating the lipopolysaccharide-induced cellular response. However, the upstream signaling pathway that regulates this process is unknown. In this study, we describe how endoplasmic reticulum (ER) stress reversely regulates sequestosome-1 (p62)and c-Jun protein levels. Furthermore, our study reveals that expression of p62 attenuates c-Jun protein levels through the ubiquitinproteasome system. Conversely, siRNA knockdown of p62 elevates c-Jun protein levels. Immunoprecipitation and immunoblotting experiments demonstrate that p62 interacts with c-Jun and CRBN to form a ternary protein complex. Moreover, we find that CRBN knockdown completely abolishes the inhibitory effect of p62 on c-Jun. Using brefeldin A as an inducer of ER stress, we demonstrate that the p62/c-Jun axis participates in the regulation of ER stress-induced apoptosis, and that CRBN is required for this regulation. In summary, we have identified an upstream signaling pathway, which regulates p62-mediated c-Jun degradation. Our findings elucidate the underlying molecular mechanism by which p62/c-Jun axis regulates the ER stress-induced apoptosis, and provide a new molecular connection between ER stress and apoptosis.

• Journal of Microbiology and Biotechnology
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• 제31권1호
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• pp.16-24
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• 2021

Hepatitis B virus (HBV) genome P-encoded protein HBV DNA polymerase (Pol) has long been known as a reverse transcriptase during HBV replication. In this study, we investigated the impact of HBV Pol on host cellular processes, mainly apoptosis, and the underlying mechanisms. We showed a marked reduction in apoptotic rates in the HBV Pol-expressed HepG2 cells compared to controls. Moreover, a series of assays, i.e., yeast two-hybrid, GST pull-down, co-immunoprecipitation, and confocal laser scanning microscopy, identified the host factor eEF1A2 to be associated with HBV Pol. Furthermore, knockdown of eEF1A2 gene by siRNA abrogated the HBV Pol-mediated anti-apoptotic effect with apoptosis induced by endoplasmatic reticulum (ER) stress-inducer thapsigargin (TG), thus suggesting that the host factor eEF1A2 is essential for HBV Pol's anti-apoptosis properties. Our findings have revealed a novel role for HBV Pol in its modulation of apoptosis through integrating with eEF1A2.