• 제목/요약/키워드: protein phosphatase inhibition

검색결과 97건 처리시간 0.026초

PTP1B Inhibitory Secondary Metabolites from Marine-Derived Fungal Strains Penicillium spp. and Eurotium sp.

  • Sohn, Jae Hak;Lee, Yu-Ri;Lee, Dong-Sung;Kim, Youn-Chul;Oh, Hyuncheol
    • Journal of Microbiology and Biotechnology
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    • 제23권9호
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    • pp.1206-1211
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    • 2013
  • The selective inhibition of PTP1B has been widely recognized as a potential drug target for the treatment of type 2 diabetes and obesity. In the course of screening for PTP1B inhibitory fungal metabolites, the organic extracts of several fungal species isolated from marine environments were found to exhibit significant inhibitory effects, and the bioassay-guided investigation of these extracts resulted in the isolation of fructigenine A (1), cyclopenol (2), echinulin (3), flavoglaucin (4), and viridicatol (5). The structures of these compounds were determined mainly by analysis of NMR and MS data. These compounds inhibited PTP1B activity with 50% inhibitory concentration values of 10.7, 30.0, 29.4, 13.4, and 64.0 ${\mu}M$, respectively. Furthermore, the kinetic analysis of PTP1B inhibition by compounds 1 and 5 suggested that compound 1 inhibited PTP1B activity in a noncompetitive manner, whereas compound 5 inhibited PTP1B activity in a competitive manner.

Beneficial Effects of Marine Bioactive Substances on Bone Health, via Osteoarthritis Inhibition and Osteoblast Differentiation

  • Nguyen, Minh Hong Thi;Qian, Zhong-Ji;Jung, Won-Kyo
    • 한국해양바이오학회지
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    • 제5권4호
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    • pp.1-7
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    • 2011
  • Bone health is maintained by balance between bone resorption and bone formation, and bone homeostasis requires balanced interactions between osteoblasts and osteoclasts. Most of drugs and functional foods for bone health have been developed as bone resorption inhibitors, which maintain bone mass by inhibiting the function of osteoclasts. The recent studies have shown beneficial effects of marine natural products on bone health. Therefore, this review is aimed to study effects of marine-derived natural substances on osteoarthritis inhibition via attenuation of MMPs and osteoblastic differentiation via activation of alkaline phosphatase (ALP), osteoclacin (OC), bone morphogenic protein-2 (BMP-2) as an important factor for bone formation, and mineralization. The present review can provide new insights in the osteoblastic differentiation of marine natural products and possibility for their application in bone health supplement.

Fraxetin Induces Heme Oxygenase-1 Expression by Activation of Akt/Nrf2 or AMP-activated Protein Kinase α/Nrf2 Pathway in HaCaT Cells

  • Kundu, Juthika;Chae, In Gyeong;Chun, Kyung-Soo
    • Journal of Cancer Prevention
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    • 제21권3호
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    • pp.135-143
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    • 2016
  • Background: Fraxetin (7,8-dihydroxy-6-methoxy coumarin), a coumarin derivative, has been reported to possess antioxidative, anti-inflammatory and neuroprotective effects. A number of recent observations suggest that the induction of heme oxygenase-1 (HO-1) inhibits inflammation and tumorigenesis. In the present study, we determined the effect of fraxetin on HO-1 expression in HaCaT human keratinocytes and investigated its underlying molecular mechanisms. Methods: Reverse transcriptase-PCR and Western blot analysis were performed to detect HO-1 mRNA and protein expression, respectively. Cell viability was measured by the MTS test. The induction of intracellular reactive oxygen species (ROS) by fraxetin was evaluated by 2′,7′-dichlorofluorescin diacetate staining. Results: Fraxetin upregulated mRNA and protein expression of HO-1. Incubation with fraxetin induced the localization of nuclear factor-erythroid-2-related factor-2 (Nrf2) in the nucleus and increased the antioxidant response element-reporter gene activity. Fraxetin also induced the phosphorylation of Akt and AMP-activated protein kinase $(AMPK){\alpha}$ and diminished the expression of phosphatase and tensin homolog, a negative regulator of Akt. Pharmacological inhibition of Akt and $AMPK{\alpha}$ abrogated fraxetin-induced expression of HO-1 and nuclear localization of Nrf2. Furthermore, fraxetin generated ROS in a concentration-dependent manner. Conclusions: Fraxetin induces HO-1 expression through activation of Akt/Nrf2 or $AMPK{\alpha}/Nrf2$ pathway in HaCaT cells.

Prostatic acid phosphatase의 전립선 암에서의 역할 (Roles of Prostatic Acid Phosphatase in Prostate Cancer)

  • 공훈영;이학종;변종회
    • 생명과학회지
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    • 제21권6호
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    • pp.893-900
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    • 2011
  • Prostatic acid phosphatase (PAP)는 전립선 암의 진단에 널리 사용되는 표지자로서 1935년 처음으로 동정되었고 인체 전립선에 가장 많이 존재하는 탈 인산화효소이다. PAP는 prostate epithelial cells에서 합성되는 전립선 특이적인 효소로서, 산성 환경에서 효소활성을 띠는 acid phosphatase 그룹에 속한다. PAP는 전립선액에 풍부히 존재하여 수정, 정자부족증, 만성통증의 감소에 관여한다. 그러나 가장 눈에 띄는 기능은 ERK1/2와 MAPK 경로에 관계된 HER-2와 PI3P의 탈 인산화를 유도하여 세포 성장 신호를 억제하고 전립선 암의 억제자로 작용하는 것이다. 최근 PAP DNA 백신을 이용하는 임상시험이 현재 진행 중이고, PAP를 이용한 immunotherapy를 통해 전립선 암을 치료하는 방법이 FDA의 승인을 받아 시행되고 있다. 이러한 PAP의 임상적 중요성에도 불구하고 현재까지 PAP의 분자적 조절기작에 대한 이해는 제한적이라 PAP에 대한 많은 연구가 필요한 실정이다. PAP는 NF-${\kappa}B$, TNF-${\alpha}$, IL-1 및 androgen과 androgen receptor에 의하여 promoter region이 조절된다고 알려졌다. 본 총설에서는 현재까지 밝혀진 PAP 유전자 및 단백질의 특징들과 더불어 전립선 암에서의 PAP의 기능, 발현 조절, 역할들을 종합하였다.

Morphine induced inhibition of the activities of accessory reproductive ducts in male rats

  • Londonkar, Ramesh L.;Sharangouda, Sharangouda;Patil, Saraswati B.
    • Advances in Traditional Medicine
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    • 제8권1호
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    • pp.67-72
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    • 2008
  • Adult male albino rats were treated with 0.5 mg and 0.75 mg morphine/100 g body weight intraperitoneally for 30 days. All the animals were autopsied on $31^{st}$ day. Epididymis and vas deferens were dissected out, weighed and processed for histological and biochemical studies. Morphine has caused a reduction in the weight of epididymis and vas deferens in both the doses of drug treated groups. The total cholesterol content is increased while protein, DNA and RNA contents and epididymal sperm counts are decreased. The acid phosphatase content is decreased 10.12 $\pm$ 0.11 in caput, 9.26 $\pm$ 0.30 in cauda of epididymis and in vas deferens 8.14 $\pm$ 0.15 in 0.5 mg treated groups and in 0.75 mg treated rats shows 9.52 $\pm$ 0.27 in caput, 9.14 $\pm$ 0.18 in cauda of epididymis and in vas deferens 7.84 $\pm$ 0.11is decreased, whereas alkaline phosphatase is increased. The surface epithelial cell height of these ducts is reduced and secretory activity is inhibited with the disruption of epithelial cell projections. The gravimetric and histometric changes of epididymis and vas deferens may be due to non-availability of androgens in morphine treated rats.

Mistletoe Lectin Induces Apoptosis and Telomerase Inhibition in Human A253 Cancer Cells through Dephosphorylation of Akt

  • Choi, Sang-Hoi;Lyu, Su-Yun;Park, Won-Bong
    • Archives of Pharmacal Research
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    • 제27권1호
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    • pp.68-76
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    • 2004
  • Mistletoe lectin has been reported to induce apoptosis in different cancer cell lines in vitro and to show antitumor activity against a variety of tumors in animal models. We previously demonstrated the Korean mistletoe lectin (Viscum album var. coloratum, VCA)-induced apoptosis by down-regulation of Bcl-2 and telomerase activity and by up-regulation of Bax through p53- and p21-independent pathway in hepatoma cells. In the present study, we observed the induction of apoptotic cell death through activation of caspase-3 and the inhibition of telomerase activity through transcriptional down-regulation of hTERT in the VCA-treated A253 cells. We also observed the inhibition of telomerase activity and induction of apoptosis resulted from dephosphorylation of Akt in the survival signaling pathways. In addition, combining VCA with the inhibitors of phosphatidylinositol 3-kinase (PI3-kinase) upstream of Akt, wortmannin and LY294002 showed an additive inhibitory effect of telomerase activity. In contrast, the inhibitor of protein phosphatase 2A (PP2A), okadaic acid inhibited VCA-induced dephosphorylation of Akt and inhibition of telomerase activity. Taken together, VCA induces apoptotic cell death through Akt signaling pathway in correlated with the inhibition of telomerase activity and the activation of caspase-3. From these results, together with our previous studies, we suggest that VCA triggers molecular changes that resulting in the inhibition of cell growth and the induction of apoptotic cell death of cancer cells, which suggest that VCA may be useful as chemotherapeutic agent for cancer cells.

감초 약침액의 항암 및 면역활성에 미치는 영향 (Antitumor and Immunomodulatory Effects of Glycyrrhizae Radix Aqua-acupuncture Solution)

  • 박경미;조경희;손윤희;임종국;남경수
    • 생약학회지
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    • 제31권1호
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    • pp.7-15
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    • 2000
  • Glycyrrhizae Radix aqua-acupuncture solution (GRAS) and Glycyrrhizae Radix water-extracted solution (GRWS) were prepared and tested for organ toxicities, antitumor activities, and immunomodulatory effects. The organ-toxicity of GRAS to male ICR mice was studied by the measurements of glutamic oxaloacetic transaminase (GOT), glutamic pyruvate transaminase (GPT), lactate dehydrogenase (LDH), and alkaline phosphatase (ALP-s) activities after injection of GRAS for 7 days. The activities of GOT, GPT, LDH, ALP-s were decreased with GRAS. It was shown to possess considerable toxicity toward various tumor cell lines. Concentration of GRAS at 1.5g/ml and 3g/ml resulted in more than 80% inhibition of growth in Ehrlich ascites tumor cells (EATC), Hepa1c1c7, and HeLa cells. Toxicity of GRAS to A549 revealed that 68% inhibition of growth. GRWS at the concentration of 3g/ml showed more than 80% inhibition of growth with EATC, Hepalclc7, A549 and HeLa. In morphological study, the number of cells were decreased, and the shape of cells was round-form in EATC, Hepalclc7, A549 and HeLa cells with GRAS. Administration of GRAS inhibited the growth of EATC in vivo. Mice given EATC at 1.5g/ml or 0.3g/ml GRAS had 16.7% to 50% survival after 21 days. GRAS increased the proliferation of T and B cells and the cytolytic activity of purified T cell. The biosyntheses of nucleic acid and protein of EATC, Hepalclc7, A549 and HeLa cells were inhibited by GRAS.

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Inhibitory Effects of Panduratin A on Periodontitis-Induced Inflammation and Osteoclastogenesis through Inhibition of MAPK Pathways In Vitro

  • Kim, Haebom;Kim, Mi-Bo;Kim, Changhee;Hwang, Jae-Kwan
    • Journal of Microbiology and Biotechnology
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    • 제28권2호
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    • pp.190-198
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    • 2018
  • Periodontitis is an inflammatory disease caused by microbial lipopolysaccharide (LPS), destroying gingival tissues and alveolar bone in the periodontium. In the present study, we evaluated the anti-inflammatory and anti-osteoclastic effects of panduratin A, a chalcone compound isolated from Boesenbergia pandurata, in human gingival fibroblast-1 (HGF-1) and RAW 264.7 cells. Treatment of panduratin A to LPS-stimulated HGF-1 significantly reduced the expression of interleukin-$1{\beta}$ and nuclear factor-kappa B (NF-${\kappa}B$), subsequently leading to the inhibition of matrix metalloproteinase-2 (MMP-2) and MMP-8 compared with that in the LPS control ($^{**}p$ < 0.01). These anti-inflammatory responses were mediated by suppressing the mitogen-activated protein kinase (MAPK) signaling and activator protein-1 complex formation pathways. Moreover, receptor activator of NF-${\kappa}B$ ligand (RANKL)-stimulated RAW 264.7 cells treated with panduratin A showed significant inhibition of osteoclastic transcription factors such as nuclear factor of activated T-cells c1 and c-Fos as well as osteoclastic enzymes such as tartrate-resistant acid phosphatase and cathepsin K compared with those in the RANKL control ($^{**}p$ < 0.01). Similar to HGF-1, panduratin A suppressed osteoclastogenesis by controlling MAPK signaling pathways. Taken together, these results suggest that panduratin A could be a potential candidate for development as a natural anti-periodontitis agent.

Changes in Human Gene Expression After Sleep Deprivation

  • Sun, Je Young;Kim, Jong Woo;Yim, Sung-Vin;Oh, Miae;Kang, Won Sub
    • 생물정신의학
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    • 제29권1호
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    • pp.9-14
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    • 2022
  • Objectives Sleep is fundamental to maintaining homeostatic control and has behavioral and psychological effects on humans. To better understand the function and pathophysiology of sleep, specific gene expressions in reference to sleep deprivation have been studied. In this study, we investigated the gene expression of peripheral blood mononuclear cells after sleep deprivation to better understand the functional consequence of sleep. Methods In eight healthy men, 24 h sleep deprivation was induced. Blood was sampled at 14:00, before and after sleep deprivation. mRNA was isolated and analyzed via microarrays. cDNAs before and after sleep deprivation were coupled to Cy3 or Cy5, respectively, and normalized cDNAs were selected with a ratio greater than two as a significant gene. Results are expressed as mean. Results Among 41174 transcripts, 38852 genes were selected as reliable, and only a small minority (< 1%) of the genes were up-or down-regulated. Total six and eleven genes were selected as significant upregulated and downregulated genes, respectively. Protein tyrosine phosphatase receptor type O was most upregulated (6.9-fold), and low-density lipoprotein receptor-related protein 5-like protein showed the most substantial inhibition (0.06-fold). Conclusions This study showed significant associations between sleep deprivation and the immune system. Acute sleep deprivation affects pathways in proinflammatory cytokines as well as metabolic pathways of glutamate and purine, neurotransmitters related to sleep and wake cycle.

Sopungsungi-won (SP) Prevents the Onset of Hyperglycemia and Hyperlipidemia in Zucker Diabetic Fatty Rats

  • Kim, Youn-Young;Kang, Hyo-Joo;Ko, Sung-Kwon;Chung, Sung-Hyun
    • Archives of Pharmacal Research
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    • 제25권6호
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    • pp.923-931
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    • 2002
  • Sopungsungi-won (SP) is a known for\mula for senile constipation and diabetes mellitus, based on traditional Korean medicine. The preventive effect of SP on the development of overt diabetes in Zucker diabetic fatty (ZDF) rats was evaluated. When administered orally through a diet for 8 weeks, diabetic conditions such as hyperglycemia, polydipsia and hypertriglyceridemia were all ameliorated in SP-treated rats. In parallel with the onset and progression of hyperglycemia in the ZDF control rats; there was a marked decline in plasma insulin concentrations from 26.1 $\mu$U/ml, at age 7 weeks, to 14.8 $\mu$U/ml at age 15 weeks. In the SP-treated rats, however, the plasma insulin concentrations did not decline, and SP at a dose of 5 g/kg significantly increased the insulin levels to 31.9 $\mu$U/ml. Early normalization of plasma insulin and a retained ability to subsequently increase plasma insulin were indicative of a pancreatic $\beta$ cell protective action by the SP for\mula. In addition, expressions of an insulin-responsive gene and corresponding protein, glucose transporter 4 (GLUT4), in skeletal \muscle, were also determined in SP- and rosiglitazone-treated ZDF rats. mRNA and protein levels of GLUT4 in SP-treated rats were upregulated in a dose dependent manner. Furthermore, when ZDF rats were treated with 2 g/kg of the SP for\mula, the activity of glucose-6-phosphatase was decreased by 49%, whereas the activity of glucokinase was increased by 196%, compared to the ZDF control rats. Taken together, these data provide evidence that the SP for\mula markedly lowered the plasma glucose levels, probably through an effect not only on improvement of insulin action, but through a combined sti\mulation of glycolysis and an inhibition of gluconeogenesis in the liver, and also suggest the validity of SP's clinical use in the treatment of type 2 diabetes mellitus following further toxicological investigation.