• Title/Summary/Keyword: transactivation

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Induction of apoptosis by etoposide treatment in colon cancer cell line SNU C2A (대장암 세포주 SNU C2A에서 etoposide 처리에 의한 apoptosis 유도)

  • Jung, Ji-Yeon;Na, Yun-sook;Jung, Ho-Chul;Oh, Sang-Jin
    • IMMUNE NETWORK
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    • v.1 no.3
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    • pp.221-229
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    • 2001
  • Background: Inactivation of tumor suppressor genes is believed to be important in the development of many human malignancies. Recently, several lines of evidence have indicated that the wild type p53 gene located at 17p13.3, may function as a tumor suppressor gene and that a mutant p53 gene could promote transformation by inactivating normal p53 function in a dominant negative fashion. These broad spectrum of p53 mutation in human cancers provide that mutant p53 and their protein may be potential targets of tumor diagnostic and therapeutic interventions. Method: Colony formation was performed to investigate growth suppressional ability. p53 expression pattern was examined by western blot and p53-mediated transactivation ability was assessed by CAT activity. SNU C2A cells were observed in apoptotic aspects induced by etoposide and $H_2O_2$ treatment, detecting sensitivity on agent, DNA fragmentation through agarose gel, chromatin condensation by fluorescence microscope, and cell cycle distribution by FACS. Result: 1) p53 mutant his179arg ($histidine{\rightarrow}arginine$) detected in SNU C2A cells lost transcriptional activity and growth suppression ability, showing dominant negative effect on its wild type p53. 2) Etoposide-treated SNU C2A cells induced apoptosis, exhibiting dramatic reduction of cell growth, DNA fragmentation, nuclear condensation formation of apoptotic body and increment of sub-G1 cell fraction. 3) Etoposide and $H_2O_2$-treated SNU C2A cells have no high increase of p53 expression and overexpressed p53 protein changed localization, from cytoplasm to nucleus. Also, p53-mediated transcriptional activity was increased by agents-treatment. Conclusion: SNU C2A cells coexpress wild-type and mutant p53 protein induced apoptosis in the condition on DNA damage, through localizational shift from cytoplasm to nucleus of p53 protein rather than the induction of p53 protein. SNU C2A cells derived mutant p53 his179arg abrogated both the growth supression ability and transactivational activity, showing inhibition effect on transcriptional activity of wild type p53, but did not repress the activity of wild type p53 in SNU C2A cells owing to dominant activity of wild type. These cell condition may provide new gene therapeutic implications leading effective antiproliferation of cell when mutant and wild-type p53 protein were co-expressed in cell.

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Polymorphisms and Functional Analysis of the Intact Human Papillomavirus16 E2 Gene

  • Ekalaksananan, Tipaya;Jungpol, Watcharapol;Prasitthimay, Chuthamas;Wongjampa, Weerayut;Kongyingyoes, Bunkerd;Pientong, Chamsai
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.23
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    • pp.10255-10262
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    • 2015
  • High risk human papillomavirus (HR-HPV) E2 proteins play roles in transcriptional regulation and are commonly functionally disrupted when the HPV genome integrates into host chromosomes. Some 15-40% of cancer cases, however, contain an intact E2 gene or episomal HPV. In these cases, polymorphism of the E2 gene might be involved. This study aimed to determine polymorphisms of the E2 gene in episomal HPV16 detected in high grade squamous intraepithelial lesions and squamous cell carcinomas and altered functions compared to the E2 prototype. The E2 gene was amplified and sequenced. Two expression vectors containing E2 gene polymorphisms were constructed and transfected in SiHa and C33A cells, then E6 gene as well as Il-10 and TNF-${\alpha}$ expression was determined by quantitative RT-PCR. Expression vectors and reporter vectors containing the HPV16 long control region (LCR) were co-transfected and transcriptional activity was determined. The results showed that a total of 32 nucleotides and 23 amino acids were changed in all 20 cases of study, found in the transactivation (TA) domain, hinge (H) region and DNA binding (DB) domain with 14, 5 and 13 nucleotide positions. They mostly caused amino acid change. The expressing vectors containing different E2 gene polymorphisms showed E6 mRNA suppression, TNF-${\alpha}$ mRNA suppression and IL-10 induction but no statistically significant differences when compared to the E2 prototype. Moreover, promoter activity in HPV16 LCR was not affected by E2 protein with different gene polymorphisms, in contrast to nucleotide variations in LCR that showed an effect on transcription activity. These results demonstrated that E2 gene polymorphisms of episomal HPV16 did not affect transcriptional regulation and suggested that nucleotide variation as well as epigenetic modification of the LCR might play a role in inducing malignant transformation of cells containing episomal HPV16.

Compound K improves skin barrier function by increasing SPINK5 expression

  • Park, No-June;Bong, Sim-Kyu;Lee, Sullim;Jung, Yujung;Jegal, Hyun;Kim, Jinchul;Kim, Si-Kwan;Kim, Yong Kee;Kim, Su-Nam
    • Journal of Ginseng Research
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    • v.44 no.6
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    • pp.799-807
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    • 2020
  • Background: The skin acts as a barrier to protect organisms against harmful exogenous agents. Compound K (CK) is an active metabolite of ginsenoside Rb1, Rb2 and Rc, and researchers have focused on its skin protective efficacy. In this study, we hypothesized that increased expression of the serine protease inhibitor Kazal type-5 (SPINK5) may improve skin barrier function. Methods: We screened several ginsenosides to increase SPINK5 gene promoter activity using a transactivation assay and found that CK can increase SPINK5 expression. To investigate the protective effect of CK on the skin barrier, RT-PCR and Western blotting were performed to investigate the expression levels of SPINK5, kallikrein 5 (KLK5), KLK7 and PAR2 in UVB-irradiated HaCaT cells. Measurement of transepidermal water loss (TEWL) and histological changes associated with the skin barrier were performed in a UVB-irradiated mouse model and a 1-chloro-2,4-dinitrobenzene (DNCB)-induced atopic dermatitis-like model. Results: CK treatment increased the expression of SPINK5 and decreased the expression of its downstream genes, such as KLKs and PAR2. In the UVB-irradiated mouse model and the DNCB-induced atopic dermatitis model, CK restored increased TEWL and decreased hydration and epidermal hyperplasia. In addition, CK normalized the reduced SPINK5 expression caused by UVB or DNCB, thereby restoring the expression of the proteins involved in desquamation to a level similar to normal. Conclusions: Our data showed that CK contributes to improving skin-barrier function in UVB-irradiated and DNCB-induced atopic dermatitis-like models through SPINK5. These results suggest that therapeutic attempts with CK might be useful in treating barrier-disrupted diseases.

Ethyl acetate fraction of GGEx18 modulates fatty acid β-oxidizing enzymes (In vitro 동물세포에서 GGEx18의 ethyl acetate 분획물에 의한 지방산 β-산화효소 유전자 발현의 조절)

  • Joo, Byung-Soo;Lee, Hee-Young;Lee, Hye-Rim;Yoon, Mi-Chung;Seo, Bu-Il;Kim, Beom-Hoi;Shin, Soon-Shik
    • The Korea Journal of Herbology
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    • v.27 no.2
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    • pp.53-59
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    • 2012
  • Objectives : This study was undertaken to investigate the effects of the GGEx18 ethyl acetate fraction (EF) on lipid accumulation and gene expression of fatty acid-oxidizing enzymes using 3T3-L1 adipocytes, C2C12 skeletal muscle cells, and NMu2Li liver cells. Methods : PPAR${\alpha}$, AMPK and UCPs transactivation was examined in NMu2Li hepatocytes, C2C12 myocytes, and 3T3-L1 preadipocytes using transient transfection assays. Results : 1. Compared with control, EF significantly increased the mRNA expression of VLCAD in 3T3-L1 adipocytes. 2. Compared with control, EF (0.1 ${\mu}g/ml$) significantly inhibited lipid accumulation in 3T3-L1 adipocytes. 3. EF significantly increased the mRNA expression of AMPK${\alpha}$1, AMPK${\alpha}$2 and PPAR${\alpha}$ in C2C12 skeletal muscle cells compared with control. 4. EF significantly increased the mRNA expression of genes involved in fatty acid ${\beta}$-oxidation, such as thiolase, MCAD, and CPT-1 in C2C12 skeletal muscle cells compared with control. 5. EF significantly increased the mRNA expression of UCP2 involved in energy expenditure in C2C12 skeletal muscle cells compared with control. 6. Compared with control, EF (10 ${\mu}g/ml$) significantly inhibited lipid accumulation in C2C12 skeletal muscle cells. 7. EF (10 ${\mu}g/ml$) significantly increased the mRNA expression of ACOX, HD, VLCAD and MCAD in NMu2Li liver cells compared with control. Conclusions : These results suggest that EF may prevent obesity by increasing the mRNA expression of mitochondrial fatty acid ${\beta}$-oxidizing enzymes in 3T3-L1 adipocytes, by not only regulating the fatty acid oxidation through activation of AMPK and PPAR${\alpha}$, but also increasing the UCP2 mRNA expression in C2C12 skeletal muscle cells, and by stimulating the mRNA expression of fatty acid-oxidizing enzymes in NMu2Li liver cells.

Molecular biologic mechanism of obesity by GGEx18 (경신강지환(輕身降脂丸)18의 분자생물학적인 비만조절 기전에 관한 연구)

  • Lee, Hee-Young;Yoon, Ki-Hyeon;Seo, Bu-Il;Park, Gyu-Ryeol;Yoon, Mi-Chung;Shen, Zhi-Bin;Cui, Hong-Hua;Shin, Soon-Shik
    • The Korea Journal of Herbology
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    • v.26 no.1
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    • pp.65-74
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    • 2011
  • Objectives : This study was undertaken to verify the modulation mechanism of Gyeongshingangjeehwan18 (GGEx18) in ob/ob male mice. Methods : Eight-week old mice (wild-type C57BL/6J and ob/ob) were used for all experiments. Wild-type C57BL/6J mice were used as lean control and obese ob/ob mice were randomly divided into 5 groups : obese control, GGEx15 (Ephedra sinica Stapf + Rheum palmatum L.), GGEx16 (Ephedra sinica Stapf + Laminaria japonica Aresch), GGEx17 (Rheum palmatum L. + Laminaria japonica Aresch), and GGEx18 (Ephedra sinica Stapf + Laminaria japonica Aresch + Rheum palmatum L.). After mice were treated with several kinds of GGEx for 11 weeks, the mRNA expression of peroxisome proliferator-activated receptor (PPAR) target genes and uncoupling protein (UCP) were measured. In addition, $PPAR{\alpha}$ and $PPAR{\beta}$ transactivation was examined in NMu2Li hepatocytes, C2C12 myocytes, and 3T3-L1 preadipocytes using transient transfection assays. Results : 1. Hepatic $PPAR{\alpha}$ target genes, such as ACOX and VLCAD mRNA levels were significantly increased by GGEx18 compared with obese controls. In skeletal muscle, LCAD mRNA expression was stimulated by GGEx16, GGEx17, and GGEx18, whereas MCAD mRNA expression by GGEx17 and GGEx18. $PPAR{\beta}$ target LPL mRNA levels were also increased by GGEx16, GGEx17, and GGEx18 in skeletal muscle, but adipose LPL mRNA levels were decreased. In addition, GGEx18 upregulated UCP mRNA expression in skeletal muslce. 2. $PPAR{\alpha}$ reporter gene expression was increased by GGEx18 in NMu2Li cells compared with vehicle. $PPAR{\alpha}$ and $PPAR{\beta}$ reporter activities were also increased by all GGEx treatments in C2C12 and 3T3-L1 cells. Conclusions : These results suggest that GGEx can act as $PPAR{\alpha}$ and $PPAR{\beta}$ activators, and that GGEx may regulate obesity by stimulating $PPAR{\alpha}$, $PPAR{\beta}$, and UCP activity. Of the 4 compositions, GGEx18 seems to be most effective in improving obesity and lipid disorders.

Gene Expression Pattern during Early Embryogenesis and Transcriptional Activities of Estrogen Receptor-Related Receptor(ERR) in Sea Urchin, Strongylocentrotus nudus (둥근성게(Strongylocentrotus nudus) Estrogen Receptor-Related Receptor(ERR)의 초기 발생시 유전자 발현 패턴과 전사 활성)

  • Maeng, Se-Jung;Kim, Mi-Soon;Sohn, Young-Chang
    • Development and Reproduction
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    • v.13 no.4
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    • pp.249-256
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    • 2009
  • The estrogen receptor-related receptors (ERRs) are a group of nuclear receptor superfamily of transcription factors. ERRs and estrogen receptors (ERs) have overlapping affinities for coactivators and DNA binding sites, but differ markedly in ligand binding and activation. The three mammalian ERR genes have been implicated in diverse physiological processes ranging from placental development to maintenance of bone density, whereas the molecular diversity, function, and regulation of ERRs in non-mammalian species are not well understood. In the present study, to investigate the involvement of ERR in transcription and embryogenesis in marine invertebrates, a cDNA encoding ERR (SnERR) was cloned from the gonad in Strongylocentrotus nudus, by polymerase chain reaction (PCR). The amino acid sequence of SnERR showed high homology with that of S. purpuratus (91%). A phylogenetic tree clearly showed that SnERR is a member of the ERR family and clustered in echinodermata group as supported by a high bootstrap value. We examined gene expression of SnERR during embryonic development of S. nudus using real-time PCR. During the embryonic development, the mRNA of ERR was significantly high levels in early development stages (4~64 cell) and larval stages. The SnERR slightly activated transcription through the classical estrogen response elements (EREs) in the presence of genistein. In addition, peroxisome proliferator-activated receptor $\gamma$ coactivator (PGC)-$1\alpha$ knwon as a coactivator of ERR enhanced the snERR-mediated transactivation, suggesting that the PGC-$1\alpha$ is a coactivator of SnERR.

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Oroxylin A Induces BDNF Expression on Cortical Neurons through Adenosine A2A Receptor Stimulation: A Possible Role in Neuroprotection

  • Jeon, Se-Jin;Bak, Hae-Rang;Seo, Jung-Eun;Han, So-Min;Lee, Sung-Hoon;Han, Seol-Heui;Kwon, Kyoung-Ja;Ryu, Jong-Hoon;Cheong, Jae-Hoon;Ko, Kwang-Ho;Yang, Sung-Il;Choi, Ji-Woong;Park, Seung-Hwa;Shin, Chan-Young
    • Biomolecules & Therapeutics
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    • v.20 no.1
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    • pp.27-35
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    • 2012
  • Oroxylin A is a flavone isolated from a medicinal herb reported to be effective in reducing the inflammatory and oxidative stresses. It also modulates the production of brain derived neurotrophic factor (BDNF) in cortical neurons by the transactivation of cAMP response element-binding protein (CREB). As a neurotrophin, BDNF plays roles in neuronal development, differentiation, synaptogenesis, and neural protection from the harmful stimuli. Adenosine $A2_A$ receptor colocalized with BDNF in brain and the functional interaction between $A2_A$ receptor stimulation and BDNF action has been suggested. In this study, we investigated the possibility that oroxylin A modulates BDNF production in cortical neuron through the regulation of $A2_A$ receptor system. As expected, CGS21680 ($A2_A$ receptor agonist) induced BDNF expression and release, however, an antagonist, ZM241385, prevented oroxylin A-induced increase in BDNF production. Oroxylin A activated the PI3K-Akt-GSK-$3{\beta}$ signaling pathway, which is inhibited by ZM241385 and the blockade of the signaling pathway abolished the increase in BDNF production. The physiological roles of oroxylin A-induced BDNF production were demonstrated by the increased neurite extension as well as synapse formation from neurons. Overall, oroxylin A might regulate BDNF production in cortical neuron through $A2_A$ receptor stimulation, which promotes cellular survival, synapse formation and neurite extension.

Inhibitory Effect of Triticum aestivum Ethanol Extract on Lipid Accumulation in 3T3-L1 Preadipocytes (3T3-L1 세포에서 소맥엽 에탄올추출물의 지질생성 억제효과)

  • Lee, Sun-Hee;Xin, Mingjie;Luyen, Bui Thi Thuy;Cha, Ji-Yun;Im, Ji-Young;Kwon, Se-Uk;Lim, Sung-Won;Suh, Joo-Won;Kim, Young-Ho;Kim, Dae-Ki;Lee, Young-Mi
    • YAKHAK HOEJI
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    • v.55 no.6
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    • pp.478-484
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    • 2011
  • Non-alcoholic fatty liver disease is known to be frequently associated with obesity and type 2 diabetes. We examined the effects of EtOH extracts from Triticum aestivum on lipid accumulation during the differentiation of 3T3-L1 preadipocytes to screening the candidate materials in preventing non-alcoholic fatty liver disease. The lipid level in adipocytes was determined by Oil Red O staining. The treatment of 50% ethanol, but not water and 100% ethanol extracts, from Triticum aestivum at concentration of 0.5 $mg/ml$ inhibited lipid accumulation in 3T3-L1 cells, revealing no cell toxicity. Thus, the fractions of $CH_2Cl_2$, EtOAc and BuOH were separated from 50% EtOH extract to characterize anti-adipogenic effect. The $CH_2Cl_2$ fraction at concentration of $50{\mu}g/ml$ effectively inhibited the lipid accumulation in the adipocytes compared to those of EtOAc and BuOH at concentration of $50{\mu}g/ml$. The intracellular triglyceride accumulation also was significantly reduced by treatment of $CH_2Cl_2$ fraction in concentration-dependent manner. Western blot analysis showed that the $CH_2Cl_2$ fraction attenuated the intracelluar level of fatty acid synthase(FAS) accompanied by attenuated expression of Peroxidase proliferator-activated receptor ${\gamma}$ ($PPAR{\gamma}$) adipogenic transcription factor. These results suggest that $CH_2Cl_2$ fraction from 50% EtOH extract of Triticum aestivum may has the potent anti-adipogenic effects by inhibiting the transactivation of $PPAR{\gamma}$.

THE RELATIONSHIP OF P63 EXPRESSION WITH CELL PROLIFERATION AND APOPTOSIS IN DMBA-INDUCED HAMSTER BUCCAL POUCH CARCINOGENESIS (DMBA 유도 햄스터 협낭 발암모델에서 세포증식 및 사멸과 p63 발현의 관계 분석)

  • Park, Jee-Hyun;Lee, Won-Deok;Min, Chul-Gi;Kang, Jin-Han;Myung, Hoon;Lee, Jong-Ho;Kim, Myung-Jin
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.31 no.3
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    • pp.219-227
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    • 2005
  • Purpose: Abnormalities in the p53 gene are regarded as the most consistent genetic abnormalities detected in head and neck squamous cell carcinogenesis. Two new members of the p53 gene family, p73 and p63 have recently been identified. They share considerable sequence homology with p53 in the transactivation, DNA binding, and oligomerization domains, indicating possible involvement in carcinogenesis. Disruption of the homeostatic balance between proliferation and apoptosis is widely believed to contribute to human oral carcinogenesis. The aim of this study was to analyze expression of p63 in squamous cell carcinogenesis and to compare with immunochemical markers representing cell proliferation and apoptosis. Materials and Methods: Using the Syrian hamster oral cancer model, the fraction of apoptotic (apoptotic index-AI), proliferating (mitotic index-MI) and p63 expressing keratinocytes were examined at normal, dysplastic and malignant oral epithelium using the TUNEL assay, PCNA and p63 immunostaining. Results: p63 significantly increased between normal and dysplastic epithelium and between dysplastic and malignant epithelium. PCNA significantly increased between normal and dysplastic epithelium and between normal and malignant epithelium. However, increase between dysplastic and malignant epithelium, though still increasing, was not statistically significant. The percentage of TUNEL positive cells increased from normal to dysplastic epithelium and returned to normal keratinocyte level in the malignant epithelium. However, differences between tissue types were not significant. The ratio of MI:AI increased significantly only in the dysplastic-malignant epithelial transition. The increase of p63 expression closely reflected the change in the MI:AI ratio during oral carcinogenesis. Conclusion: The p63 may be associated with the regulation of epithelial proliferation and apoptosis in DMBA-induced hamster buccal pouch squamous cell carcinogenesis. Further study is required to investigate which p63 isoforms are involved in hamster buccal pouch carcinogenesis.

Skin Rejuvenation by Novel Synthetic Compound Containing Retinoidal Activity (레티노이드 효과를 가지는 합성물에 의한 피부재생 효과)

  • Rho Ho Sik;Baek Heung Soo;Kim Sujong;Kim Sunam;Kim Duck Hee;Chang Ih Seop;Lee Ok-Sub
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.30 no.3 s.47
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    • pp.405-408
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    • 2004
  • Several hydroxamic acid derivatives are synthesized to observe retinoidal effect and transactivation potential for $RAR{\alpha}/{\gamma]$ is screened. Among the synthesized compounds, N-(4-N-hydroxycarbamoyl )phenyl) [4-(tert-butyl )phenyl] carboxamide (2f) showed the best compatibility for potent $RAR{\alpha}/{\gamma].$ The acidic hydroxy of hydroxamic acid was easily deprotonated to form an enolate. A formed enolate has a similar role like that of all-trans-retinoic acid. This is the first example of the hydroxamic acid derivative with retinoidal activity. The retinoidal activity of 2f was further confirmed by enhancing activity for the expression of retinoid-responsive genes. To evaluate the possibility for anti.-aging agent, effect on the expression of MMP-1 was measured comparing with all-trans-retinoic acid and retinol. At 10 uM treatment, compound 2f inhibited the expression of MMP-1. These results suggest that new hydroxamic acid derivative 2f could be used as a promising anti-aging agent.