316 results on '"Yoon-Jeong Choi"'
Search Results
302. Anti-fibrogenic effect of umbilical cord–derived mesenchymal stem cell–conditioned media in human esophageal fibroblasts
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Yoon Jeong Choi, Jee Hyun Kim, Yeonju Lee, Hee Jang Pyeon, In Kyung Yoo, and Jun Hwan Yoo
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Esophageal fibrosis ,Mesenchymal stem cells ,Umbilical cord ,Conditioned medium ,Medicine ,Science - Abstract
Abstract Esophageal fibrosis can develop due to caustic or radiation injuries. Umbilical cord–derived mesenchymal stem cells (UC-MSCs) are known to mitigate fibrosis in various organs. However, the potential effects of UC-MSCs on human esophageal fibrosis remain underexplored. This study investigated the anti-fibrogenic properties and mechanisms of UC-MSC-derived conditioned media (UC-MSC-CM) on human esophageal fibroblasts (HEFs). HEFs were treated with TGF-β1 and then cultured with UC-MSC-CM, and the expression levels of extracellular matrix (ECM) components, RhoA, myocardin related transcription factor A (MRTF-A), serum response factor (SRF), Yes-associated protein (YAP), and transcriptional coactivator with PDZ-binding motif (TAZ) were measured. UC-MSC-CM suppressed TGF-β1-induced fibrogenic activation in HEFs, as evidenced by the downregulation of ECM. UC-MSC-CM diminished the expression of RhoA, MRTF-A, and SRF triggered by TGF-β1. In TGF-β1-stimulated HEFs, UC-MSC-CM decreased the nuclear localization of MRTF-A and YAP. Additionally, UC-MSC-CM diminished the TGF-β1-induced nuclear expressions of YAP and TAZ, while concurrently enhancing the cytoplasmic presence of phosphorylated YAP. Furthermore, UC-MSC-CM reduced TGF-β1-induced phosphorylation of Smad2. These findings suggest that UC-MSC-CM may inhibit TGF-β1-induced fibrogenic activation in HEFs by targeting the Rho-mediated MRTF/SRF and YAP/TAZ pathways, as well as the Smad2 pathway. This indicates its potential as a stem cell therapy for esophageal fibrosis.
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- 2024
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303. READER'S FORUM.
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Sanghee Lee, Soonshin Hwang, Woowon Jang, Yoon Jeong Choi, Chung, Chooryung J., and Kyung-Ho Kim
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THREE-dimensional imaging ,RADIOPACITY ,BONE density - Published
- 2019
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304. Ideal metal-decorated three dimensional covalent organic frameworks for reversible hydrogen storage.
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Yoon Jeong Choi, Jung Woo Lee, Jung Hoon Choi, and Jeung Ku Kang
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NUCLEAR physics , *SURFACE chemistry , *NUCLEAR energy , *NONMETALS , *HYDROGEN , *SEPARATION (Technology) - Abstract
The most stable H2 adsorption on pure covalent organic frameworks (COFs) occurs near O atoms, but its binding energy (∼0.05 eV) is not sufficient to satisfy the minimum value (0.24 eV) required for practical applications. Meanwhile, Li and Mg ion-decorated COFs have hydrogen adsorption energies of 0.28 and 0.30 eV, respectively, and their saturated hydrogen storage capacities exceed the DOE target (6.5 wt %). Also the effect of some counterions on hydrogen storage has been explored. Moreover, doped ions prefer to exist as isolated elements on COFs, which is another advantage to realize hydrogen storage media. [ABSTRACT FROM AUTHOR]
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- 2008
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305. Umbilical Cord/Placenta-Derived Mesenchymal Stem Cells Inhibit Fibrogenic Activation in Human Intestinal Myofibroblasts via Inhibition of Myocardin-Related Transcription Factor A.
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Yoon Jeong Choi, Jun Bon Koo, Hee Yeon Kim, Jin Won Seo, Eun Jeong Lee, Woo Ram Kim, Joo Young Cho, Ki Baik Hahm, Sung Pyo Hong, Duk Hwan Kim, and Jun-hwan Yoo
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MESENCHYMAL stem cells , *TRANSCRIPTION factors , *SERUM response factor , *INFLAMMATORY bowel diseases , *CROHN'S disease , *FIBRONECTINS - Abstract
Background/Aims The lack of anti-fibrotic agents targeting intestinal fibrosis is a large unmet need in inflammatory bowel diseases, including Crohn's disease and ulcerative colitis. Previous studies have found that perinatal tissue (umbilical cord [UC], placenta [PL]) derived mesenchymal stem cells (MSCs) reduce fibrosis in several organs. However, their effects on human intestinal fibrosis are poorly understood. This study investigated the anti- fibrogenic properties and mechanisms of MSCs derived from UC and PL (UC/PL-MSCs) on human primary intestinal myofibroblasts (HIMFs). Methods The HIMFs were treated with transforming growth factor-β1 (TGF-β1) and co-cultured with UC/PL-MSCs. We used a small molecular inhibitor CCG-100602 to examine whether serum response factor (SRF) and its transcriptional cofactor myocardin-related transcription factor A (MRTF-A) are involved in TGF-β1-induced fibrogenic activation in HIMFs. The anti-fibrogenic mechanism of UC/PL-MSCs on HIMFs was analyzed by detecting the expression of RhoA, MRTF-A, and SRF in HIMFs. Results UC/PL-MSCs reduced TGF-β1-induced procollagen1A1, fibronectin, and α-smooth muscle actin expression in HIMFs. This anti-fibrogenic effect was more apparent in the UC-MSCs. TGF-β1 stimulation increased the expressions of RhoA, MRTF-A, and SRF in the HIMFs. TGF-β1 induced the synthesis of procollagen1A1, fibronectin, and α-smooth muscle actin through a MRTF-A/SRF dependent mechanism. Co-culture with the UC/PL-MSCs down regulated fibrogenesis by inhibition of RhoA, MRTF-A, and SRF expression. Conclusions UC/PL-MSCs suppress TGF-β1-induced fibrogenic activation in HIMFs by blocking the Rho/MRTF/SRF pathway and could be considered as a novel candidate for stem cell-based therapy of intestinal fibrosis. [ABSTRACT FROM AUTHOR]
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- 2019
306. Genetic polymorphisms linked to extreme postorthodontic external apical root resorption in Koreans
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Jing Liu, Kwanwoo Park, Yoon Jeong Choi, Ji Hyun Lee, and Jung-Yul Cha
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Genetic polymorphisms ,External apical root resorption ,Orthodontic treatment ,Dentistry ,RK1-715 - Abstract
Abstract Background External apical root resorption (EARR) is a common undesirable outcome of orthodontic treatment, this study aimed to identify genetic polymorphisms associated with the susceptibility to extreme orthodontic-induced EARR in a Korean population using extreme phenotype analysis sampling. Methods Genomic DNA was isolated from the saliva of 77 patients who underwent orthodontic treatment involving two maxillary premolar extractions. The patients were divided into two groups based on EARR values measured on periapical radiographs: The significant resorption group (SG, EARR ≥ 4 mm) and the normal group (NG, EARR
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- 2024
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307. READER'S FORUM.
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Jung Jin Park, Young-Chel Park, Kee-Joon Lee, Jung-Yul Cha, Ji Hyun Tahk, and Yoon Jeong Choi
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MAXILLARY expansion ,CORRECTIVE orthodontics - Published
- 2017
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308. Human umbilical cord/placenta mesenchymal stem cell conditioned medium attenuates intestinal fibrosis in vivo and in vitro
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Yoon Jeong Choi, Woo Ram Kim, Duk Hwan Kim, Jee Hyun Kim, and Jun Hwan Yoo
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Intestinal fibrosis ,Conditioned medium ,Mesenchymal stem cells ,Umbilical cord ,Placenta ,Medicine (General) ,R5-920 ,Biochemistry ,QD415-436 - Abstract
Abstract Background A significant unmet need in inflammatory bowel disease is the lack of anti-fibrotic agents targeting intestinal fibrosis. This study aimed to investigate the anti-fibrogenic properties and mechanisms of the conditioned medium (CM) from human umbilical cord/placenta-derived mesenchymal stem cells (UC/PL-MSC-CM) in a murine intestinal fibrosis model and human primary intestinal myofibroblasts (HIMFs). Methods UC/PL-MSC-CM was concentrated 15-fold using a 3 kDa cut-off filter. C57BL/6 mice aged 7 weeks old were randomly assigned to one of four groups: (1) control, (2) dextran sulfate sodium (DSS), (3) DSS + CM (late-phase treatment), and (4) DSS + CM (early-phase treatment). Chronic DSS colitis and intestinal fibrosis was induced by three cycles of DSS administration. One DSS cycle consisted of 7 days of oral DSS administration (1.75%, 2%, and 2.5% DSS), followed by 14 days of drinking water. UC/PL-MSC-CM was intraperitoneally administered in the late phase (from day 50, 10 times) or early phase (from day 29, 10 times) of DSS cycles. HIMFs were treated with TGF-β1 and co-treated with UC/PL-MSC-CM (10% of culture media) in the cellular model. Results In the animal study, UC/PL-MSC-CM reduced submucosa/muscularis propria thickness and collagen deposition, which improved intestinal fibrosis in chronic DSS colitis. The UC/PL-MSC-CM significantly reduced the expressions of procollagen1A1 and α-smooth muscle actin, which DSS significantly elevated. The anti-fibrogenic effect was more apparent in the UC-MSC-CM or early-phase treatment model. The UC/PL-MSC-CM reduced procollagen1A1, fibronectin, and α-smooth muscle actin expression in HIMFs in the cellular model. The UC/PL-MSC-CM downregulated fibrogenesis by suppressing RhoA, MRTF-A, and SRF expression. Conclusions Human UC/PL-MSC-CM inhibits TGF-β1-induced fibrogenic activation in HIMFs by blocking the Rho/MRTF/SRF pathway and chronic DSS colitis-induced intestinal fibrosis. Thus, it may be regarded as a novel candidate for stem cell-based therapy of intestinal fibrosis.
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- 2024
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309. Can medication-related osteonecrosis of the jaw be attributed to specific microorganisms through oral microbiota analyses? A preliminary study
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Heon-Young Kim, Young-Soo Jung, Wonse Park, Yoon Jeong Choi, and Jun-Young Kim
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Medication-related osteonecrosis of the jaw ,Microbiome ,Oral bacteria ,Metagenomics ,Dentistry ,RK1-715 - Abstract
Abstract Background Medication-related osteonecrosis of the jaw (MRONJ) can cause significant pain and loss of aesthetics and function if not treated properly. However, diagnosis still relies on detailed intraoral examinations and imaging. Prognosis varies even among patients with similar stages or conditions of MRONJ, emphasizing the need for a deeper understanding of its complex mechanisms. Thus, this study aimed to identify the oral microbiota of patients with MRONJ. Methods This single-center prospective cohort study included patients with confirmed MRONJ who visited the Department of Oral and Maxillofacial Surgery at Yonsei University Dental Hospital between 2021 and 2022. Oral swab samples were collected from the affected and unaffected sides of each patient. The composition and enumeration of the microbial communities were analyzed, and the diversity was compared to verify ecological changes in the groups using a next-generation sequencing-based 16S metagenomic analysis. A statistical analysis was performed using Wilcoxon signed-rank test with SPSS version 22, and values of P less than 0.05 were considered statistically significant. Results The final study sample included 12 patients. The mean age was 82.67 ± 5.73 (range, 72–90) years. Changes in microbial composition were observed at different taxonomic levels (phylum, genus, and species). The identified microorganisms were commonly associated with periodontitis, gingival disease, and endodontic infection, suggesting a multifactorial etiology of MRONJ. Conclusions Although this study is based on a small number of cases, it shows that MRONJ is not caused by a specific microorganism but can rather be caused by a variety of factors. By addressing these findings in large-scale studies, the significance of oral microbiome in pathogenesis can be further elucidated and can facilitate the development of effective therapeutic interventions for patients with MRONJ.
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- 2024
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310. TO-GO: a Java-based Gene Ontology navigation environment.
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Ungsik Yu, Yoon Jeong Choi, Jung Kyoon Choi, and Sangsoo Kim
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- 2005
311. PhD DISSERTATION ABSTRACT.
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Yoon-Jeong Choi
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THEATER education , *CROSS-cultural communication , *COMMUNICATION , *ENGLISH as a foreign language , *CULTURE , *TEACHING - Abstract
Explores intercultural communication (ICM) through drama using six central concepts of ICM, otherness, outsidedness, duality, dialecticality and dialogicality. Examination of these concepts in the context of intercultural drama in teaching English as an international language; Characteristics of intercultural drama in relation to those concepts; Dynamics of cultural drama.
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- 2004
312. The effect of genetic polymorphisms on treatment duration following premolar extraction
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Jiyon Yu, Yoon Jeong Choi, Sung-Hwan Choi, Han-Sung Jung, Ji Hyun Lee, and Jung-Yul Cha
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Medicine ,Science - Abstract
Abstract To elucidate genetic factors affecting orthodontic treatment duration, we employed targeted next-generation sequencing on DNA from the saliva of 117 patients undergoing orthodontic treatment after premolar extraction. The clinical characteristics of patients are summarized, and the association of clinical variables with treatment duration was assessed. Patients whose treatment duration deviated from the average were classified into an extreme long group or an extreme short group. We identified nine single nucleotide polymorphisms (SNPs) of six genes that significantly differed in the two groups via targeted sequencing. The frequency of the CC genotypes of WNT3A, SPP1 (rs4754, rs9138), and TNFSF11, TT genotype of SPP1 (rs1126616), and GG genotype of SFRP2 was significantly higher in the extreme long group than in the short group. In the extreme short group, the TC genotype of SPP1, AA genotype of P2RX7, CT genotype of TNFSF11, and AG genotype of TNFRSF11A tended to exhibit higher frequency than in the long group. Taken together, we identified genetic polymorphisms related to treatment duration in Korean orthodontic patients undergoing premolar extraction. Our findings could lead to further studies predicting the prolongation of the orthodontic treatment duration, and will be of great aid to patients as well as orthodontists.
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- 2021
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313. Effect of the Number of Micro-Osteoperforations on the Rate of Tooth Movement and Periodontal Response in Mice
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Tselmuun Erdenebat, Dong-Joon Lee, Su-Jung Kim, Yoon Jeong Choi, Eun-Jung Kim, Eun-Hack Choi, Jing Liu, Chung-Ju Hwang, Han-Sung Jung, and Jung-Yul Cha
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micro-osteoperforation ,orthodontic tooth movement ,micro-CT ,root resorption ,cementum ,bone formation ,Physiology ,QP1-981 - Abstract
Accelerated tooth movement can be achieved using micro-osteoperforations (MOPs) to stimulate regeneration of the alveolar bone during minimally invasive surgical trauma. However, there is currently no standardized protocol and limited reports regarding the side effects of MOPs based on biological evidence. This study sought to evaluate the biological effects of the number of MOPs on orthodontic tooth movement (OTM) and the potential risk for root resorption. Male CD1 mice were divided into 4 groups based on the number of MOPs, as follows: Sham; 0MOP+OTM; 2MOP+OTM; and 4MOP+OTM groups. Tooth movement distance and the number of osteoclasts were higher whereas bone volume and trabecular number were lower in the 4MOP+OTM group compared to those of the 0MOP+OTM group. Immunofluorescent assay analysis indicated that the 4MOP+OTM group was positively associated with rapid cementum regeneration and periodontal ligament tissue formation. Our findings revealed that the MOP procedure affected tooth movement and did not significantly contribute to root resorption, whereas it may promote constitutive activation of cementogenesis.
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- 2022
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314. Evaluation of the Hemodynamics of a Tissue-engineered Hybrid Graft.
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Kuk Hui Son, Yong Hu Fang, Yoon Jeong Choi, Insup Noh, Jae Kyung Won, Yongdoo Park, Sung Ho Lee, Kyung Sun, and Ho Sung Son
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HEMODYNAMICS , *BLOOD circulation , *TISSUES , *POLYTEF , *MUSCLE cells - Abstract
We evaluated the hemodynamics of tissue-engineered hybrid graft in vivo. The hybrid expanded polytetrafluoroethylene (ePTFE) scaffold was fabricated by coating the ePTFE graft with poly (lactide-co-glycolide) (PLGA) solution. This scaffold was turned into an engineered hybrid graft by culturing smooth muscle cells on its surface. Both the ePTFE ( n = 6) and the engineered hybrid grafts ( n = 8) were implanted in the carotid arteries of mongrel dogs. The length of intima in the engineered hybrid graft was greater than the ePTFE. The neoarterial thickness in the engineered hybrid group was greater, and the foreign body reaction was more severe. We compared the hemodynamics (diameter, flow rate, pulsatile index, mean velocity, shear stress, resistance index, and systolic/diastolic ratio) of the native arteries in the distal anastmosis. The shear rate in the engineered hybrid group was higher immediately after implantation, and the resistance index was lower, but there was no significant difference after 4 weeks. The engineered grafts demonstrated similar hemodynamics with the ePTFE grafts after 4 weeks implantation. [ABSTRACT FROM AUTHOR]
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- 2010
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315. BBS7–SHH Signaling Activity Regulates Primary Cilia for Periodontal Homeostasis
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Pi En Chang, Shujin Li, Hyun-Yi Kim, Dong-Joon Lee, Yoon Jeong Choi, and Han-Sung Jung
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BBS7 gene ,shh signaling pathway ,primary cilia ,periodontal homeostasis ,occlusal hypofunction ,Biology (General) ,QH301-705.5 - Abstract
Objectives: Mechanical stimuli are essential for the maintenance of periodontal ligament (PDL) homeostasis. Although there are several studies on atrophic changes in PDL due to occlusal hypofunction, the underlying mechanism is still unknown. Here, we aimed to explore the changes of gene expression in occlusal hypofunctional PDL and elucidate the related role in maintaining the PDL homeostasis.Methods: To investigate the transcriptomic difference between control and hypofunctional PDL tissue from patients, RNA sequencing was performed on 34 human teeth. The atrophic changes in PDL were evaluated by histological analysis. The effect of the Bardet-Biedl syndrome 7 (BBS7) knockdown was evaluated by the RT-qPCR, Western blot, wound healing, and tubule formation assay.Results: We detected that the expression of BBS7 was downregulated in occlusal hypofunctional PDL through RNA sequencing. Dynamic changes, including the number of periodontal ligament cells, alignment of collagen fibers, diameter of blood vessels, appearance of primary cilia, and torturous oxytalan fibers, were observed following occlusal hypofunction. Furthermore, Sonic hedgehog signaling (Shh) activity was closely associated with BBS7 expression in PDL cells. In addition, the cell migration and angiogenesis were also suppressed by BBS7 knockdown in vitro.Conclusion: We suggest that BBS7 plays an essential role in maintaining Shh signaling activity for PDL homeostasis.
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- 2021
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316. Açaí Berries Inhibit Colon Tumorigenesis in Azoxymethane/Dextran Sulfate Sodium-Treated Mice
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Yoon Jin Choi, Yoon Jeong Choi, Nayoung Kim, Ryoung Hee Nam, Seonmin Lee, Hye Seung Lee, Ha-Na Lee, Young-Joon Surh, and Dong Ho Lee
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açaí berry ,colorectal neoplasms ,anti-inflammatory ,proapoptotic ,Diseases of the digestive system. Gastroenterology ,RC799-869 - Abstract
Background/AimsThe aim of this study was to investigate the protective effect of açaí against azoxymethane (AOM)/dextran sulfate sodium (DSS)-induced colorectal cancer development.Methods : The effect of açaí on tumorigenesis was assessed by evaluating tumor incidence, multiplicity and invasiveness in the mouse colon. The levels of myeloperoxidase (MPO) and proinflammatory cytokines (tumor necrosis factor α [TNF-α], interleukin [IL]-1β, and IL-6) were measured via enzyme-linked immunosorbent assay. Protein levels of cyclooxygenase 2 (COX-2), proliferating cell nuclear antigen (PCNA), B-cell lymphoma 2 (Bcl-2), Bcl-2-associated death promoter (Bad) and cleaved-caspase-3 were assessed by immunoblotting.Results : Administration of pellets containing 5% açaí powder reduced the incidences of both colonic adenoma and cancer (adenoma, 23.1% vs 76.9%, respectively, p=0.006; cancer, 15.4% vs 76.9%, respectively, p=0.002). In the açaí-treated mice, the MPO, TNF-α, IL-1β and IL-6 levels in the colon were significantly down-regulated. Açaí inhibited PCNA and Bcl-2 expression and increased Bad and cleaved-caspase-3 expression. In vitro studies demonstrated that açaí treatment reduced lipopolysaccharide-induced expression of TNF-α, IL-1β, IL-6 and COX-2 in murine macrophage RAW 264.7 cells.Conclusion : sAçaí demonstrated protective effects against AOM/DSS-induced colon carcinogenesis, which suggests that the intake of açaí may be beneficial for the prevention of human colon cancer.
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- 2017
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