• Title/Summary/Keyword: inhibitory receptor

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Inhibitory Effects and Molecular Mechanism of Adipocyte Differentiation by Rosae laevigata Fructus Ethanol Extracs (금앵자 에탄올 추출물에 의한 3T3-L1 지방세포의 분화억제 효과와 그 메커니즘 규명)

  • Jeong, Hyun Young;Jeong, In Kyo;Nam, So Yeon;Yun, Hee Jung;Kim, Byung Woo;Kwon, Hyun Ju
    • Microbiology and Biotechnology Letters
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    • v.44 no.1
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    • pp.89-97
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    • 2016
  • Obesity is caused by excess accumulation of body fat and contributes to various pathological disorders such as diabetes, hypertension, cardiovascular disease, and cancer. In this study, we investigated the effect of a 30% ethanol extract of Fructus Rosae laevigata (RLE) on adipogenesis in 3T3-L1 adipocytes, measured by triglyceride accumulation and expression of adipogenesis-related transcription factors during differentiation of pre-adipocytes into adipocytes. RLE decreased the intracellular triglyceride contents (assessed by Oil Red-O staining) in a dose-dependent manner. It also downregulated the expression of adipogenic transcription factors and inhibited cell proliferation during the mitotic clonal expansion phase of adipocyte differentiation by inducing G1 phase arrest. We investigated the alterations in the levels of G1 phase arrest-related proteins. The expression of p21 protein significantly increased, while the levels of Cyclin E, Cdk2, and phospho-Rb decreased in a dose-dependent manner in 3T3-L1 cells treated with RLE. These results suggest that RLE inhibits the differentiation of 3T3-L1 adipocytes by suppressing the expression of adipogenic transcription factors and inducing G1 phase arrest in the early stages of adipocyte differentiation.

Inhibition of Microbial Quorum Sensing Mediated Virulence Factors by Pestalotiopsis sydowiana

  • Parasuraman, Paramanantham;Devadatha, B;Sarma, V. Venkateswara;Ranganathan, Sampathkumar;Ampasala, Dinakara Rao;Reddy, Dhanasekhar;Kumavath, Ranjith;Kim, In-Won;Patel, Sanjay K.S.;Kalia, Vipin Chandra;Lee, Jung-Kul;Siddhardha, Busi
    • Journal of Microbiology and Biotechnology
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    • v.30 no.4
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    • pp.571-582
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    • 2020
  • Quorum sensing (QS)-mediated infections cause severe diseases in human beings. The control of infectious diseases by inhibiting QS using antipathogenic drugs is a promising approach as antibiotics are proving inefficient in treating these diseases. Marine fungal (Pestalotiopsis sydowiana PPR) extract was found to possess effective antipathogenic characteristics. The minimum inhibitory concentration (MIC) of the fungal extract against test pathogen Pseudomonas aeruginosa PAO1 was 1,000 ㎍/ml. Sub-MIC concentrations (250 and 500 ㎍/ml) of fungal extract reduced QS-regulated virulence phenotypes such as the production of pyocyanin, chitinase, protease, elastase, and staphylolytic activity in P. aeruginosa PAO1 by 84.15%, 73.15%, 67.37%, 62.37%, and 33.65%, respectively. Moreover, it also reduced the production of exopolysaccharides (74.99%), rhamnolipids (68.01%), and alginate (54.98%), and inhibited the biofilm formation of the bacteria by 90.54%. In silico analysis revealed that the metabolite of P. sydowiana PPR binds to the bacterial QS receptor proteins (LasR and RhlR) similar to their respective natural signaling molecules. Cyclo(-Leu-Pro) (CLP) and 4-Hydroxyphenylacetamide (4-HPA) were identified as potent bioactive compounds among the metabolites of P. sydowiana PPR using in silico approaches. The MIC values of CLP and 4-HPA against P. aeruginosa PAO1 were determined as 250 and 125 ㎍/ml, respectively. All the antivirulence assays were conducted at sub-MIC concentrations of CLP (125 ㎍/ml) and 4-HPA (62.5 ㎍/ml), which resulted in marked reduction in all the investigated virulence factors. This was further supported by gene expression studies. The findings suggest that the metabolites of P. sydowiana PPR can be employed as promising QS inhibitors that target pathogenic bacteria.

Effects of Octreotide on the Contractility of Isolated Rat Vas Deferens (흰쥐 정관의 수축성에 미치는 Octreotide의 영향)

  • Jang, Sun-Ae;Kwon, Oh-Cheol;Ha, Jeoung-Hee;Lee, Kwang-Youn;Kim, Won-Joon
    • Journal of Yeungnam Medical Science
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    • v.10 no.1
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    • pp.144-156
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    • 1993
  • This study was performed to investigate the effect of octreotide on the contractility of rat vas deferens. The smooth muscle strips isolated from the prostatic portion were myographied in isolated organ bath, Electric field stimulation (monophasic square wave, duration: 1 mSec, voltage : 50 V, frequency : 5 Hz or 30 Hz, train: 10 Sec) produced reproducible contraction. The contraction was composed of two component, first phasic component (FPC) and second tonic component (STC). These contractions were abolished by tetrodotoxin ($1{\mu}M$). Octreotide inhibited the field stimulation induced contractions both FPC and STC concentration-dependently. The FPC was decreased by a desentization of purinergic receptor by pretreatment of mATP, and the STC was decreased by pretreatment of reserpine(3 mg/kg, IP) 24 hours before experiments. Octreotide reduced the field stimulation induced contraction in the presence of mATP and of reserpinized muscle strips. The inhibitory effect of octreotide was more potent at 5 Hz than at 30 Hz. Octreotide did not affect basal ton and exogenous norepinephrine- or ATP-induced contraction. These results suggest that octreotide inhibit the contractility of the isolated rat vas deferens by inhibition of the release of neurotransmitters, both ATP and norepinephrine from adrenergic nerve terminal.

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PKA-Mediated Regulation of B/K Gene Transcription in PC12 Cells

  • Choi, Mi-Hyun;Kim, Ho-Shik;Choi, Sung-Ho;Kim, Mi-Young;Jang, Yoon-Seong;Jang, Young-Min;Lee, Jeong-Hwa;Jeong, Seong-Whan;Kim, In-Kyung;Kwon, Oh-Joo
    • The Korean Journal of Physiology and Pharmacology
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    • v.9 no.6
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    • pp.333-339
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    • 2005
  • B/K protein is a novel protein containing double C2-like domains. We examined the specific signaling pathway that regulates the transcription of B/K in PC12 cells. When the cells were treated with forskolin ($50{\mu}M$), B/K mRNA and protein levels were time-dependently decreased, reaching the lowest level at 3 or 4 hr, and thereafter returning to the control level. Chemicals such as dibutyryl-cAMP, cellpermeable cyclic AMP (cAMP) analogue and CGS21680, adenosine receptor $A_{2A}$ agonist, also repressed the B/K transcription. However, 1,9-dideoxyforskolin did not show inhibitory effect on B/K transcription, suggesting direct involvement of cAMP in the forskolin-induced inhibition of B/K transcription. Effect of forskolin, dibutyryl cAMP and CGS21680 was significantly reduced in PKA-deficient PC12 cell line (PC12-123.7). One cAMP-response element (CRE)-like sequence (B/K CLS) was found in the promoter region of B/K DNA, and electrophoretic mobility shift assay indicated its binding to CREM and CREB. Forskolin significantly suppressed the promoter activity in CHO-K1 cells transfected with the constructs containing B/K CLS, but not with the construct in which B/K CLS was mutated (AC:TG). Taken together, we suggest that the transcription of B/K gene in PC12 cells may be regulated by PKA-dependent mechanism.

Hexane-Soluble Fraction of the Common Fig, Ficus carica, Inhibits Osteoclast Differentiation in Murine Bone Marrow-Derived Macrophages and RAW 264.7 Cells

  • Park, Young-Ran;Eun, Jae-Soon;Choi, Hwa-Jung;Nepal, Manoj;Kim, Dae-Keun;Seo, Seung-Yong;Li, Rihua;Moon, Woo-Sung;Cho, Nam-Pyo;Cho, Sung-Dae;Bae, Tae-Sung;Kim, Byung-Il;Soh, Yun-Jo
    • The Korean Journal of Physiology and Pharmacology
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    • v.13 no.6
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    • pp.417-424
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    • 2009
  • Osteoclasts, derived from multipotent myeloid progenitor cells, play homeostatic roles in skeletal modeling and remodeling, but may also destroy bone in pathological conditions such as osteoporosis and rheumatoid arthritis. Osteoclast development depends critically on a differentiation factor, the receptor activator of NF-${\kappa}B$ ligand (RANKL). In this study, we found that the hexane soluble fraction of the common fig Ficus carica (HF6-FC) is a potent inhibitor of osteoclastogenesis in RANKL-stimulated RAW264.7 cells and in bone marrow-derived macrophages (BMMs). HF6-FC exerts its inhibitory effects by suppression of p38 and NF-${\kappa}B$ but activation of ERK. In addition, HF6-FC significantly decreased the expression of NFATc1 and c-Fos, the master regulator of osteoclast differentiation. The data indicate that components of HF6-FC may have therapeutic effects on bone-destructive processes such as osteoporosis, rheumatoid arthritis, and periodontal bone resorption.

Anti-obesity Effects of Ginsenoside Rd via AMPK and PPAR Gamma (진세노사이드 Rd의 AMPK 및 PPAR 감마의 신호전달경로를 통한 항비만효과)

  • Kim, Myung-Sunny;Lee, Myoung-Soo;Kim, Soon-Hee;Kim, Sung-Hee;Kim, Hyun-Jin;Sung, Mi-Jeong;Kim, Hye-Young;Kwon, Dae-Young;Hwang, Jin-Taek
    • KSBB Journal
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    • v.22 no.5
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    • pp.341-344
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    • 2007
  • Obesity is a major obstacle for human health, which induces various diseases such as cardiac injury and type 2 diabetes. Ginsenosides, active components of ginseng extract, exert various physiological effects. However, There are still no evidence for their anti obesity effects. In this study, we investigated the effects of ginsenoside Rd on adipocyte differentiation in 3T3-L1 cells. Our data show that ginsenoside Rd (80 uM) was effective in adipocyte differentiation inhibition. These inhibitory effects of ginsenosides on adipocyte differentiation were accompanied by PPAR gamma inhibition in rosiglitazone-treated cells. We also tested whether AMP-activated protein kinase (AMPK) activation was involved in the effects of these ginsenosides. AMPK is a master target for obesity, ginsenoside Rd significantly activated AMPK. Taken together, these results suggest that the anti obesity effects of ginsenoside Rd involve the AMPK signaling pathway and PPAR-gamma inhibition.

Effects of Joint Mobilization Techniques on the Joint Receptors (관절 가동운동(mobilization)이 관절 감수기(joint receptors)에 미치는 영향)

  • Kim, Suhn-Yeop
    • Physical Therapy Korea
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    • v.3 no.2
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    • pp.95-105
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    • 1996
  • Type I, II, III are regarded as "true" joint receptors, type IV is considered a class of pain receptor. Type I, II and III mechanoreceptors, via static and dynamic input, signal joint position, intraarticular pressure changes, and the direction, amplitude, and velocity of joint movements. Type I mechanoreceptor subserve both static and dynamic physiologic functions. Type I are found primarily in the stratum fibrosum of the joint capsule and ligaments. Type I receptors have a low threshold for activation and are allow to adapt to changes altering their firing frequency. Type II receptors have a low threshold for activation. These dynamic receptors respond to joint movement. Type II receptors are thus termed rapidly adapting. Type II joint receptors are located at the junction of the synovial membrane and fibrosum of the joint capsule and intraarticular and extraarticular fat pads. Type III receptors have been found in collateral ligaments of the joints of the extremities. Morphologically similar to Golgi tendon organ. These dynamic receptors have a high threshold to stimulation and are slowly adating. Type IV receptors possess free nerve ending that have been found in joint capsule and fat pads. They are not normally active, but respond to extreme mechanical deformation of the joint as well as to direct chemical or mechanical irritation. Small amplitude oscillatory and distraction movements(joint mobilization) techniques are used to stimulate the mechanoreceptors that may inhibit the transmission of nociceptors stimuli at the spinal cord or brain stem levels.

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Prostaglandin E2 Reverses Curcumin-Induced Inhibition of Survival Signal Pathways in Human Colorectal Carcinoma (HCT-15) Cell Lines

  • Shehzad, Adeeb;Islam, Salman Ul;Lee, Jaetae;Lee, Young Sup
    • Molecules and Cells
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    • v.37 no.12
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    • pp.899-906
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    • 2014
  • Prostaglandin $E_2$ ($PGE_2$) promotes tumor-persistent inflammation, frequently resulting in cancer. Curcumin is a diphenolic turmeric that inhibits carcinogenesis and induces apoptosis. $PGE_2$ inhibits curcumin-induced apoptosis; however, the underlying inhibitory mechanisms in colon cancer cells remain unknown. The aim of the present study is to investigate the survival role of $PGE_2$ and whether addition of exogenous $PGE_2$ affects curcumininduced cell death. HCT-15 cells were treated with curcumin and $PGE_2$, and protein expression levels were investigated via Western blot. Reactive oxygen species (ROS) generation, lipid peroxidation, and intracellular glutathione (GSH) levels were confirmed using specific dyes. The nuclear factor-kappa B ($NF-{\kappa}B$) DNA-binding was measured by electrophoretic mobility shift assay (EMSA). $PGE_2$ inhibited curcumin-induced apoptosis by suppressing oxidative stress and degradation of PARP and lamin B. However, exposure of cells to the EP2 receptor antagonist, AH6809, and the PKA inhibitor, H89, before treatment with $PGE_2$ or curcumin abolished the protective effect of $PGE_2$ and enhanced curcumin-induced cell death. $PGE_2$ activates PKA, which is required for cAMP-mediated transcriptional activation of CREB. $PGE_2$ also activated the Ras/Raf/Erk pathway, and pretreatment with PD98059 abolished the protective effect of $PGE_2$. Furthermore, curcumin treatment greatly reduced phosphorylation of CREB, followed by a concomitant reduction of $NF-{\kappa}B$ (p50 and p65) subunit activation. $PGE_2$ markedly activated nuclear translocation of $NF-{\kappa}B$. EMSA confirmed the DNA-binding activities of $NF-{\kappa}B$ subunits. These results suggest that inhibition of curcumin-induced apoptosis by $PGE_2$ through activation of PKA, Ras, and $NF-{\kappa}B$ signaling pathways may provide a molecular basis for the reversal of curcumin-induced colon carcinoma cell death.

Inhibitory Effect of Combination with Korean Red Gnseng and Morus Alba in High Fructose-induced Vascular Inflammation and Steatohepatitis (고과당식이 투여 랫드모델에서 홍삼과 상엽 복합투여에 대한 혈관염증 및 지방간염 억제 효과)

  • Lee, Yun Jung;Yoon, Jung Joo;Lee, So Min;Kho, Min Chul;Kim, Hye Yoom;Ahn, You Mee;Kho, Joung Hyun;Lee, Kee Byoung;Lee, Ho Sub;Choi, Kyung Min;Kwon, Tae Oh;Kang, Dae Gill
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.26 no.5
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    • pp.724-731
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    • 2012
  • This study was designed to elucidate whether combination with Korean red ginseng and Morus alba L. (MPM), traditional treatment for diabetes, ameliorates on high fructose-induced steatohepatitis and vascular inflammation. Animals were divided into four groups; Control receiving tap water, fructose-fed, rosiglitazone-treated fructose-fed rats, and MPM-treated fructose-fed rats both receiving supplemented with 60% fructose (n=10). The MPM or rosiglitazone groups initially received a high-fructose diet alone for 8 weeks, with supplementation with MPM or rosiglitazone, peroxisome proliferators-activated receptor gamma ($PPAR{\gamma}$) agonist, occurring during the final 6 weeks. Treatment with MPM significantly prevented the increase in c-reactive protein (CRP) levels in the high fructose group. MPM suppressed high fructose diet-induced vascular inflammation marker expression such as intracellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin. MPM also reduced intima/media thickness of thoracic aorta. Histologic observation and oil red O staining demonstrated hepatic tissue damage and lipid accumulation were severe in high fructose group. Treatment with MPM ameliorated hepatic tissue morphology with minimized steatosis. In addition, MPM attenuated hepatitis by inhibition of monocyte chemoattractant protein-1 (MCP-1) expression. MPM-fed group showed lower serum GOT and GPT levels comparing with high fructose group. MPM and rosiglitazone (positive control) significantly decreased the size of epididymal adipocytes. Taken together, the administration of MPM inhibited high fructose-induced steatohepatitis and vascular inflammation. These results suggested that MPM is useful in the prevention or treatment of metabolic syndrome-related disorders such as fatty acid metabolism and vascular homeostasis.

Inhibitory Effects of Allium sacculiferum Max. Methanol Extracts on ROS Production and Lipid Accumulation during Differentiation of 3T3-L1 Cells (참산부추(Allium sacculiferum Max.) 메탄올 추출물의 지방세포 내 ROS 생성 및 지질 축적 억제 효능)

  • Choi, Hye-Young;Kim, Gun-Hee
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.43 no.6
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    • pp.822-828
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    • 2014
  • Allium sacculiferum Max. (ASM) is a perennial plant of the Liliaceae family and grows over the entire regions of Korea. Obesity is a serious health problem worldwide and has currently become a prevalent chronic disease. Adipocytes produced by preadipocyte differentiation during adipogenesis and adipocytes combined with abnormal accumulation cause obesity. Recently, intracellular reactive oxygen species (ROS) were shown to accelerate lipid accumulation in 3T3-L1 cells. In this study, we investigated the effects of ASM methanol extracts on ROS production and lipid accumulation in 3T3-L1 adipocytes. Our results indicate that the 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity of ASM methanol extracts increased in a dose-dependent manner. ASM methanol extracts suppressed ROS production and lipid accumulation during adipogenesis. In addition, ASM methanol extracts inhibited the mRNA expression of both pro-oxidant enzymes such as glucose-6-phosphate dehydrogenase as well as the transcription factors, including sterol regulatory element-binding proteins 1c, peroxisome proliferator-activated receptor ${\gamma}$, and CCAAT/enhancer-binding protein ${\alpha}$. Our results suggest that ASM methanol extracts inhibit ROS production and lipid accumulation by controlling ROS regulatory genes and adipogenic transcription factors. Thus, ASM has potent natural antioxidant, anti-adipogenic properties and have potential in the development of a potent anti-obesity agent.