• 제목/요약/키워드: Release mechanism

검색결과 899건 처리시간 0.031초

Transition Metal Induces Apoptosis in MC3T3E1 Osteoblast: Evidence of Free Radical Release

  • Chae, Han-Jung;Chae, Soo-Wan;Kang, Jang-Sook;Yun, Dong-Hyeon;Bang, Byung-Gwan;Kang, Mi-Ra;Kim, Hyung-Min;Kim, Hyung-Ryong
    • The Korean Journal of Physiology and Pharmacology
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    • 제4권1호
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    • pp.47-54
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    • 2000
  • Transition metal ions including $Se^{2+},\;Cd^{2+},\;Hg^{2+}\;or\;Mn^{2+}$ have been thought to disturb the bone metabolism directly. However, the mechanism for the bone lesion is unknown. In this study, we demonstrated that MC3T3E1 osteoblasts, exposed to various transition metal ions; selenium, cadmium, mercury or manganese, generated massive amounts of reactive oxygen species (ROS). The released ROS were completely quenched by free radical scavengers-N-acetyl cysteine (NAC), reduced glutathione (GSH), or superoxide dismutase (SOD). First, we have observed that selenium $(10\;{\mu}M),$ cadmium $(100\;{\mu}M),$ mercury $(100\;{\mu}M)$ or manganese (1 mM) treatment induced apoptotic phenomena like DNA fragmentation, chromatin condensation and caspase-3-like cysteine protease activation in MC3T3E1 osteoblasts. Concomitant treatment of antioxidant; N-acetyl-L-cysteine (NAC), reduced-form glutathione (GSH), or superoxide dismutase (SOD), prevented apoptosis induced by each of the transition metal ions. Catalase or dimethylsulfoxide (DMSO) has less potent inhibitory effect on the apoptosis, compared with NAC, GSH or SOD. In line with the results, nitroblue tetrazolium (NBT) stain shows that each of the transition metals is a potent source of free radicals in MC3T3E1 osteoblast. Our data show that oxidative damage is associated with the induction of apoptosis in MC3T3E1 osteoblasts following $Se^{2+},\;Cd^{2+},\;Hg^{2+}\;or\;Mn^{2+}$ treatment.

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Reduction of Food Intake by Fenofibrate is Associated with Cholecystokinin Release in Long-Evans Tokushima Rats

  • Park, Mi-Kyoung;Han, Ying;Kim, Mi-Sun;Seo, Eun-Hui;Kang, Soo-Jeong;Park, So-Young;Koh, Hyeong-Jong;Kim, Duk-Kyu;Lee, Hye-Jeong
    • The Korean Journal of Physiology and Pharmacology
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    • 제16권3호
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    • pp.181-186
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    • 2012
  • Fenofibrate is a selective peroxisome proliferator-activated receptor ${\alpha}$ ($PPAR{\alpha}$) activator and is prescribed to treat hyperlipidemia. The mechanism through which $PPAR{\alpha}$ agonists reduce food intake, body weight, and adiposity remains unclear. One explanation for the reduction of food intake is that fenofibrate promotes fatty acid oxidation and increases the production of ketone bodies upon a standard experimental dose of the drug (100~300 mg/kg/day). We observed that low-dose treatment of fenofibrate (30 mg/kg/day), which does not cause significant changes in ketone body synthesis, reduced food intake in Long-Evans Tokushima (LETO) rats. LETO rats are the physiologically normal controls for Otsuka Long-Evans Tokushima Fatty (OLETF) rats, which are obese and cholecystokinin (CCK)-A receptor deficient. We hypothesized that the reduced food intake by fenofibrate-treated LETO rats may be associated with CCK production. To investigate the anorexic effects of fenofibrate in vivo and to determine whether CCK production may be involved, we examined the amount of food intake and CCK production. Fenofibrate-treated OLETF rats did not significantly change their food intake while LETO rats decreased their food intake. Treatment of fenofibrate increased CCK synthesis in the duodenal epithelial cells of both LETO and OLETF rats. The absence of a change in the food intake of OLETF rats, despite the increase in CCK production, may be explained by the absence of CCK-A receptors. Contrary to the OLETF rats, LETO rats, which have normal CCK receptors, presented a decrease in food intake and an increase in CCK production. These results suggest that reduced food intake by fenofibrate treatment may be associated with CCK production.

실험계획법을 이용한 이탈방지 스냅핏의 최적설계 (Optimum Design of Lock Snap-fit Using Design of Experiment)

  • 손인서;신동길
    • 한국산학기술학회논문지
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    • 제18권8호
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    • pp.378-385
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    • 2017
  • 본 연구는 플라스틱 부품의 체결에 널리 활용되고 있는 스냅핏의 설계에 관하여 연구하였다. 이탈방지 기능이 우수한 이탈방지 스냅핏은 형상과 체결 메카니즘이 복잡하여 기존의 이론식에 기반한 체결력과 이탈력을 해석적으로 구할 수가 없다. 따라서 본 연구에서는 이탈방지 스냅핏에 대하여 체결 메커니즘을 분석하고, 실험계획법에 기반하여 체결력 및 이탈력을 측정하고, 분산분석을 통하여 회귀식을 도출하였다. 실험계획은 중심합성계획을 사용하였다. Polybutylene terephthalate를 이용하여 시편을 제작하여 미소인장시험기를 이용하여 체결력과 이탈력을 측정하였다. 설계인자는 Length, Width, Thickness, Interference 등 4개를 선정하였으며, 2차 회귀모형을 이용하여 체결력과 이탈력에 대한 회귀식을 도출하였다. Length와 Width가 증가할수록 체결력은 낮아졌으며, Thickness와 Interference는 증가할수록 체결력이 증가하였다. 이탈력은 체결력과 반대의 결과를 나타내었다. 유한요소법을 이용하여 체결 역학에 대하여 분석하였다. Width는 체결단계에서 단면관성모멘트의 증가를 통한 보의 강성 증가 효과 보다는, 오히려 길이 증가에 따른 연성증대로 인하여 체결력을 감소시키는 것으로 나타났다. 낮은 체결력과 높은 이탈력을 위한 인자들의 영향도는 서로 상반되는 것으로 나타났다. 적정 수준의 이탈력을 유지하면서 체결력을 최소화하는 설계가 필요한 것으로 나타났다.

A1E Induces Apoptosis via Targeting HPV E6/E7 Oncogenes and Intrinsic Pathways in Cervical Cancer Cells

  • Ham, Sun Young;Bak, Ye Sol;Kwon, Tae Ho;Kang, Jeong Woo;Choi, Kang Duk;Han, Tae Young;Han, Il Young;Yang, Young;Jung, Seung Hyun;Yoon, Do Young
    • Journal of Applied Biological Chemistry
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    • 제57권2호
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    • pp.103-111
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    • 2014
  • A1E is an extract from traditional Asian medicinal plants that has therapeutic activities against cancers, metabolic disease, and other intractable conditions. However, its mechanism of action on cervical cancer has not been studied. In order to ascertain if A1E would have pronounced anti-cervical cancer effect, cervical cancer cells were incubated with A1E and apoptosis was detected by nuclear morphological changes, annexin V-FITC/PI staining, cell cycle analysis, western blotting, Reverse-transcription polymerase chain reaction, and measurement of mitochondrial membrane potential. Expression of human papiloma virus E6 and E7 oncogenes was down-regulated in A1E-treated cervical cancer cells, while p53 and retinoblastoma protein levels were enhanced. A1E also perturbed cell cycle progression at sub-G1 and altered cell cycle regulatory factors in SiHa cervical cancer cells. A1E activated apoptotic intrinsic pathway markers such as caspase-9, caspase-3 and poly ADP-ribose polymerase, and down-regulated expression of Bcl-2 and Bcl-xl. A1E induced mitochondrial membrane potential collapse and cytochrome c release, and inhibited phosphatidylinositol 3-kinase (PI3K)/Akt, key factors involved in cell survival signaling. Taken all these results, A1E induced apoptosis via activation of the intrinsic pathway and inhibition of the PI3K/Akt survival-signaling pathway in SiHa cervical cancer cells. In conclusion, A1E exerts anti-proliferative action growth inhibition on cervical cancer cells through apoptosis which demonstrates its anti-cervical cancer properties.

포중익기탕(補中益氣湯)이 알레르기 비염(鼻炎) 유발 마우스에 미치는 효과(效果) (The Effect of the Bojungikgi-tang in a Mouse Model of Allergic Rhinitis)

  • 김선민;심성용;변학성;김경준
    • 한방안이비인후피부과학회지
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    • 제18권3호
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    • pp.26-36
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    • 2005
  • Objectives: Maier symptoms of allergic rhinitis are nasal obstructions, sneezing and watery rhinorrhea. When exposed to certain allergens, the IgE covered mast cells degranulate and release inflammatory mediators and cytokines which result in a local inflammatory reaction. In many recent studies, molecular biological methods have been used to investigate the role of cytokines in pathogenesis and new therapeutic targets of allergic rhinitis. This experimental study was done to reveal the effects of the Bojungikgi-tang on the allergic rhinitis. We have studied effect of mice on OVA-induced production of IL-4, IL-5, $INF-{\gamma}$ by murine splenocytes and effect of OVA-induced Total IgE and OVA-specific IgE Meterial and Metheds: 21 BALB/c rats were divided into three groups: normal group, control group, experimental group. To induce the allergic rhinitis in control group and experimental group, rats were sentitized intraperitioneally with 0.1% ovalbumin solution 3 times at intervals of 2 weeks. Then intranasal sensitization was performed by diffusing 0.1% ovalbumin solution 3 times at intervals of 2 days for a week. After that time, rats in experimental group were oral administration treated by the Bojuogikgi-tang fer 28 days. We observed changes of IL-4, IL-5, $INF-{\gamma}$, Total IgE and OVA-specific IgE. We used independent-test statistically. Results: 1. In IL-4 study, Bojungikgi-tang treated group didn't show significant differences. 2. In IL-5 study, Bojungikgi-tang treated group shows significant differences. 3. In $INF-{\gamma}$ study, Bojungikgi-tang treated group shows significant differences. 4. In Total IgE, Bojungikgi-tang treated group shows significant differences. 5. In OVA-specific IgE, Bojungikgi-tang treated group didn't show significant differences. According to this result, Bojungikgi-tang was concluded to be effective on lowering the total IgE. Through this. Bojungikgi tang seems to reduce the symptoms of allergic rhinitis. More studies are required to know exact mechanism of Bojungikgi tang to show the anti allergenic effect.

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가미지황환이 저산소성 신경세포 손상에 미치는 영향 (Influence of Kamijihwang-hwan on the Hypoxic Damage of Cultured Cerebral Neurons from mouse and SK-N-MC cells)

  • 백은경;주성민;김근중;김대근;강정호;이영찬;이준;김영목;전병훈
    • 동의생리병리학회지
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    • 제17권4호
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    • pp.1082-1091
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    • 2003
  • To elucidate the neuroprotective effect of Kamijihwang-hwan(KSH) on nerve cells damaged by hypoxia, the cytotoxic effects of exposure to hypoxia were determined by XTT, NR, MTT and SRB asssay. The activity of catalase and SOD was measured by spectrophometry, and TNF-α and PKC activity was measured after exposure to hypoxia and treatment of Kamijihwang-hwan(KSH) water extract(KJHWE). Also the neuroprotective effect of KJHWE was researched for the elucidation of neuroprotective mechanism. The results were as follows ; Hypoxia decreased cell viability measured by XTT, NR assay when cultured cerebral neurons were exposed to 95% N2/5% CO₂ for 2~26 minutes in these cultures and KJHWE inhibited the decrease of cell viability. H₂O₂ treatment decreased cell viability measured by MTT, and SRB assay when cultured cerebral neurons were exposed to 1-80 uM for 6 hours, but KJHWE inhibited the decrease of cell viability. Hypoxia decreased catalase and SOD activity, and also TNF-α and PKC activity in these cultured cerebral neurons, but KJHWE inhibited the decrease of the catalase and SOD activity in these cultures. Hypoxia triggered the apoptosis via caspase activation and internucleosomal DNA fragmentation. Also hypoxia stimulate the release of cytochrome c form mitochondria. KJHWE inhibited the apoptosis via caspase activation induced by hypoxia. From these results, it can be suggested that brain ischemia model induced hypoxia showed neurotoxity on cultured mouse cerebral neurons, and the KJHWE has the neuroprotective effect in blocking the neurotoxity induced by hypoxia in cultured mouse cerebral neurons.

Betulinic Acid Inhibits LPS-Induced MMP-9 Expression by Suppressing NF-kB Activation in BV2 Microglial Cells

  • Lee, Jae-Won;Choi, Yong-Joon;Kim, Song-In;Lee, Sue-Young;Kang, Sang-Soo;Kim, Nam-Ho;Kwon, Yong-Soo;Lee, Hee-Jae;Chun, Wan-Joo;Kim, Sung-Soo
    • Biomolecules & Therapeutics
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    • 제19권4호
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    • pp.431-437
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    • 2011
  • Aberrant activation of microglia has been reported to cause neuronal damages by releasing a variety of pro-inflammatory cytokines. Besides where microglia become active, damages have been also observed in remote places, which is considered due to the migration of activated microglia. Therefore, an agent that could suppress abnormal activation of microglia and their subsequent migration might be valuable in activated microglia-related brain pathologies. The objective of the present study was to evaluate anti-inflammatory effects of betulinic acid on lipopolysaccharide (LPS)-stimulated BV2 microglial cells. Pretreatment of betulinic acid significantly attenuated LPS-induced NO production and protein expression of iNOS. Betulinic acid also significantly suppressed LPS-induced release and expression of cytokines such as TNF-${\alpha}$ and IL-$1{\beta}$. Furthermore, betulinic acid significantly uppressed LPS-induced MMP-9 expression, which has been suggested to play an important role in the migration of activated microglia. In order to understand the possible mechanism by which betulinic acid suppresses LPS-induced cytokine production and migration of microglia, the role of NF-kB, a major pro-inflammatory transcription factor, was examined. Betulinic acid significantly suppressed LPS-induced degradation of IKB, which retains NF-kB in the cytoplasm. Therefore, nuclear translocation of NF-kB upon LPS stimulation was significantly suppressed with betulinic acid. Taken together, the present study for the first time demonstrates that betulinic acid possesses anti-inflammatory activity through the suppression of nuclear translocation of NF-kB in BV2 microglial cells.

가미소요산의 새로운 제형에 대한 항산화 활성 및 항염증 효능평가 (Evaluation on Anti-oxidant Activity and Anti-inflammatory Effects for the New Formulation of Gamisoyosan)

  • 최혜민;김세진;김인수;이지범;김종범;문성옥;이화동
    • 대한본초학회지
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    • 제31권6호
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    • pp.1-9
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    • 2016
  • Objectives : Gamisoyosan (GMS) is a useful prescription for treating insomnia, dysmenorrhea and infertility induced by a stress. Also, GMS has been used traditionally to improve systemic circulation and biological energy production. The purpose of this study was to assess the anti-oxidant activity and anti-inflammatory effects of Gamisoyosan Formulation (Soft extract, GMS-SE). Methods : The biological activities such as anti-oxidant and anti-inflammatory effects were measured through cell line-based in vitro assay. We investigated the anti-oxidant properties of GMS-SE on the 1,1-diphenyl-2-picryhydrazyl (DPPH) radical, contents of total flavonoid and polyphenol. GMS-SE compared to butyl hydroxy anizole (BHA). Furthermore, based on this result the anti-inflammatory effects of GMS-SE have verified by mechanism from LPS- treated Raw264.7 macrophages. Results : The anti-oxidant activities of GMS-SE increased markedly, in a dose-dependent manner. The GMS-SE showed significant scavenging activity (GMS-SE $500{\mu}g/m{\ell}$ : $32.77{\pm}1.65%$, GMS-SE $1000{\mu}g/m{\ell}$ : $45.06{\pm}1.04%$ and BHA $100{\mu}g/m{\ell}$ : $39.25{\pm}2.41%$ for DPPH assay). and, The total phenolic compound and flavonoids contents of GMS-SE were $73.93{\pm}6.87{\mu}g/mg$ and $698.75{\pm}6.78{\mu}g/mg$. GMS-SE which is LPS has diminished in the LPS-induced release of inflammatory mediators (NO, iNOS, COX2 and PGE2) and pro-inflammatory cytokines (TNF-${\alpha}$, IL-6 and IL-$1{\beta}$) from the RAW264.7 macrophages. Moreover, GMS-SE inhibited the activation of phosphorylation of p38 and ERK MAPKs by induced LPS. Conclusion : The present results indicate that GMS-SE has an anti-oxidant and anti-inflammatory properties, therefore may be beneficial in diseases which related to oxidative stress-mediated inflammatory disorders.

흰쥐의 적출배뇨근에서 baclofen의 콜린성신경 억제작용 (Effect of Baclofen on the Cholinergic Nerve Stimulation in Isolated Rat Detrusor)

  • 이광윤;이근미;최은미;최형철;하정희;김원준
    • Journal of Yeungnam Medical Science
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    • 제12권2호
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    • pp.246-259
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    • 1995
  • 배뇨근의 운동성에 대한 baclofen의 억제작용의 기전을 탐구하기 위하여 다음과 같은 실험을 하였다. 흰쥐 (Sprague-Dawley)의 방광에서 적출한 배뇨근절편을 적출근편실험조에 현수하고, 등척성 장력측정기를 사용하여 그 수축력을 묘기하였다. 실험조내의 영양액의 온도는 $37^{\circ}C$로 유지시키고, 95% 산소와 5% 이산화탄소의 혼합기체를 공급하여 pH를 7.4로 유지하였다. 배뇨근절편은 전기장자극에 의해 수축하였는데, 8분간의 전기장자극 유발수축 중 최초의 급격한 수축반응은 mATP와 baclofen에 의해 약간 억제되는 경향을 보였으며, 후기 4분간의 수축반응은 콜린성 무스카린성 수용체 봉쇄제인 atropine과 $GABA_B$ 수용체 효현제인 baclofen에 의해 유의하게 억제되었다. Atropine은 배뇨근 절편의 acetylcholine 유발 수축을 길항하였고, mATP는 ATP 유발 수축을 완전히 봉쇄하였으나, baclofen 존재하에서는 acetylcholine이나 ATP 첨가에 의한 배뇨근의 수축이 영향을 받지 않았다. 이상의 결과를 종합하면, 흰쥐 방광에는 $GABA_B$ 수용체가 존재하며 baclofen은 이 수용체를 통하여 콜린성신경 말단에서의 신경전달체의 유리를 억제하여 배뇨근의 수축성을 감소시킨다고 사료된다.

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과학기술과 착취 : 자본주도형 기술 개발의 한계 (Technology and Exploitation : Limitation of Capitalist Technological Development)

  • 신은화
    • 철학연구
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    • 제146권
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    • pp.115-135
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    • 2018
  • 이 논문은 과학기술이 인간 삶의 편리함과 윤택함에 기여하기 보다는 오히려 인간을 억압하고 착취하는 수단으로 전락하는 문제를 다룬다. 이와 관련하여 필자는 노동가치론과 '기술가치론'의 상이한 주장들을 검토하면서 노동과 기술의 문제에 대해 고찰해보고자 한다. 또한 필자는 기술의 '자본주의적' 사용에 대한 마르크스의 비판적 관점을 적극 참고하면서, 특히 마르크스의 상대적 잉여가치 및 특별잉여가치 개념, 자본의 유기적 구성의 고도화에 관한 분석에 주목할 것이다. 그의 견해는 오늘날 기술의 발전이 노동자에 대한 통제 및 업무강도 강화, 고용불안 심화로 초래되는 문제를 설명하는 데 있어서 여전히 유효함을 확인받고 있다. 필자는 자본주도형 기술 개발의 한계를 성찰하는 것이 기술 그 자체의 본래적 이점을 제대로 활용하기 위해서 매우 중요한 일이라고 보며, 기술이 우리 생활에 '실질적인' 풍요로움과 안락함을 가져오도록 하는 데 중요한 몇 가지 사항들을 짚어보고자 한다. 이와 관련하여 핵심적인 것은 노동자를 착취하는 수단이 되지 않고 노동자의 이해관계와 대치되지 않는 기술의 사용가능성일 것이다. 이런 이유에서 필자는 기술의 자본주의적 사용 문제를 근본적으로 해결하는 것은 아니지만 그것의 극단적인 추구와는 다른 방향성을 나타내는 독일의 Industrie 4.0의 전개과정을 주목해볼 필요가 있다고 본다.