• 제목/요약/키워드: Endogenous Growth

검색결과 287건 처리시간 0.031초

VEGF-VEGFR Signals in Health and Disease

  • Shibuya, Masabumi
    • Biomolecules & Therapeutics
    • /
    • 제22권1호
    • /
    • pp.1-9
    • /
    • 2014
  • Vascular endothelial growth factor (VEGF)-VEGF receptor (VEGFR) system has been shown to play central roles not only in physiological angiogenesis, but also in pathological angiogenesis in diseases such as cancer. Based on these findings, a variety of anti-angiogenic drugs, including anti-VEGF antibodies and VEGFR/multi-receptor kinase inhibitors have been developed and approved for the clinical use. While the clinical efficacy of these drugs has been clearly demonstrated in cancer patients, they have not been shown to be effective in curing cancer, suggesting that further improvement in their design is necessary. Abnormal expression of an endogenous VEGF-inhibitor sFlt-1 has been shown to be involved in a variety of diseases, such as preeclampsia and aged macular degeneration. In addition, various factors modulating angiogenic processes have been recently isolated. Given this complexity then, extensive studies on the interrelationship between VEGF signals and other angiogenesis-regulatory systems will be important for developing future strategies to suppress diseases with an angiogenic component.

유채 하배축 분절의 신장과 세포벽 분해효소의 활성에 미치는 IAA의 효과 (Effects of IAA on the Elongation and Cell Wall Glycosidase Activities in Excised Rape (Brassica napus L. cv. Yongdang) Hypocotyl Segments)

  • Jun, Sung-Soo
    • Journal of Plant Biology
    • /
    • 제27권2호
    • /
    • pp.43-50
    • /
    • 1984
  • Effects of IAA on the elongation and cell wall hlysocidase activities were investigated in excised rape (Brassica napus L. cv. Yongdang) hypocotyl segments. IAA promoted the elongation of rape hypocotyl segments. In rape hypocotyls, the first 10-mm segments from the hook exhibited maximal elongation and the capacity of elongation was gradually decreased with increasing distance of each 10-mm from the hook. A good correlation has been obtained between the magnitude of endogenous growth and the activities of $\alpha$, $\beta$-glucosidase and $\alpha$, $\beta$-galactosidase. However, exogenous application of IAA did not seem to enhance the tissue with IAA resulted in acidification of the incubation medium. From these data, we can conclude that IAA seems to enhance elongation of the tissue segments, at least in part, by releasing hydrogen ion into cell wall, some of which may participate in the cell wall extension process, but does not seem to trigger the activation of $\alpha$, $\beta$-glucosidase and $\alpha$, $\beta$-galactosidase.

  • PDF

Cymbidium sp. Protocorm의 묘조분화시 내생 Polyamine 함량의 변화 (Change of Endogenous Polyamines During Shoot Differentiation in Cymbidium sp. Protocorms)

  • 한태진
    • Journal of Plant Biology
    • /
    • 제33권1호
    • /
    • pp.41-48
    • /
    • 1990
  • Changes in polamine titers during shoot differentiation in Cymbidium sp. (Jungfrau) protocorms were studied in order to investigate the mechanism of shoot differentiation by using auxin-inhibitors(PCIB, TIBA), hormones(GA3, ABA, BA), and phenolic compounds (2,4-dichlorophenol, catechol). The shoot differentiation and propagation of protocorms were promoted by PCIB or 2,4-dichlorophenol, and the growth of differentiated shoot were promoted by TIBA or catechol. In BA-treated protocorms, white or brown protocorms were observed. Putrescine was the most abundant polyamine during the propagation and differentiation processes. As compared with putrescine, spermidine did not show significant changes and spermine was not detected at all. Putrescine titers decreased after a temporary increase, and then again increased in the presence of GA3, ABA, 2,4-dichlorophenol, and then again increased in the presence of GA3, ABA, 2,4-dichlorophenol, catechol, or PCIB. But, in BA-treated protocorms, putrescine level was much lower than spermidine.

  • PDF

Enhanced Healing of Rat Calvarial Bone Defects with Hypoxic Conditioned Medium from Mesenchymal Stem Cells through Increased Endogenous Stem Cell Migration via Regulation of ICAM-1 Targeted-microRNA-221

  • Chang, Woochul;Kim, Ran;Park, Sang In;Jung, Yu Jin;Ham, Onju;Lee, Jihyun;Kim, Ji Hyeong;Oh, Sekyung;Lee, Min Young;Kim, Jongmin;Park, Moon-Seo;Chung, Yong-An;Hwang, Ki-Chul;Maeng, Lee-So
    • Molecules and Cells
    • /
    • 제38권7호
    • /
    • pp.643-650
    • /
    • 2015
  • The use of conditioned medium from mesenchymal stem cells may be a feasible approach for regeneration of bone defects through secretion of various components of mesenchymal stem cells such as cytokines, chemokines, and growth factors. Mesenchymal stem cells secrete and accumulate multiple factors in conditioned medium under specific physiological conditions. In this study, we investigated whether the conditioned medium collected under hypoxic condition could effectively influence bone regeneration through enhanced migration and adhesion of endogenous mesenchymal stem cells. Cell migration and adhesion abilities were increased through overexpression of intercellular adhesion molecule-1 in hypoxic conditioned medium treated group. Intercellular adhesion molecule-1 was upregulated by microRNA-221 in mesenchymal stem cells because microRNAs are key regulators of various biological functions via gene expression. To investigate the effects in vivo, evaluation of bone regeneration by computed tomography and histological assays revealed that osteogenesis was enhanced in the hypoxic conditioned medium group relative to the other groups. These results suggest that behavioral changes of endogenous mesenchymal stem cells through microRNA-221 targeted-intercellular adhesion molecule-1 expression under hypoxic conditions may be a potential treatment for patients with bone defects.

패널구조방정식을 활용한 IT기업의 R&D투자효과 연구: 특허 매개효과 중심으로 (R&D Investment Effect through Patent on IT firms using Panel Structural Equations)

  • 이종호;김태환;정우진
    • 지식경영연구
    • /
    • 제21권1호
    • /
    • pp.137-150
    • /
    • 2020
  • This study analyzes not only the direct impact of R&D investment on corporate growth for 578 private firms in 2007-2016, but also whether corporate innovation activities play a role as a mediating parameter between R&D investment and corporate growth. For this purpose, we classify companies into IT and non-IT companies and measure the mediating effect by dividing innovation activities into the number of registered patents, applied patents, and sum of them. In addition, this study is based on both the systemGMM which is considered to be effective in solving the endogenous problems caused by the cross-sectional analysis in previous studies and ML-SEM which is a new method recently, and then compares two results. According to the empirical results, innovation activities has a role as partly mediating parameter on sales growth in non-IT companies. On the other hands, in IT companies, the increase in R&D investment leads to a decrease in sales of the company, and the increase in innovation activities increases the sales of the company. However, it was confirmed that IT companies also had positive effects by adjusting the lag of the R&D. In other words, this suggests that securing patents is more important than R&D investment for direct sales growth of IT companies. It is also evidence that immediate introduction of technology is necessary to respond to the speed of technological change since the cycle time of technologies of the IT field is relatively shorter compared to that of other fields.

질소추비와 생장조정제 Inabenfide 처리가 벼 도복 및 에틸렌 발생에 미치는 영향 (Effect of Inabenfide and Nitrogen Top-Dressing on Ethylene Evolution and Lodging in Rice)

  • Lee, Sang-Chul;Takeshi, Tanabe
    • 한국작물학회지
    • /
    • 제38권5호
    • /
    • pp.383-390
    • /
    • 1993
  • 본 실험은 1992년 일본 동경농업대학 온실에서 질소 추비와 생장억제제 처리가 벼의 생육과 도복형질에 미치는 형태학적 특성과의 관계를 조사함과 동시에 내성 에틸렌 발생에 미치는 영향을 구명하기 위하여 실험을 수행한바 아래와 같은 결과를 얻었다. 1. 식물생장억제제인 Inabenfide는 초장은 감소시켰지만 수량구성요소, 엽록소 함량, $CO_2 동화량 및 분벽에는 변화가 없었다. 2. Inabenfide를 수잉기에 처리하였을 때 절간 신장을 감소시켰으나, 세 번째와 네 번째의 절간 직경과 줄기의 두께를 증가시켰다. 3. 질소추비는 대체로 초장과 $CO_2 동화률에는 뚜렷하게 영향을 나타내지 않았다. 4. 에틸렌 발생은 생장억제제에 대하여 많은 변화를 보여 주었으며 Inabenfide를 출수 15일 전에 처리하였을 때 에틸렌 발생은 무처리구보다 낮게 나타났다. 5. 질소 추비량에 따른 에틸렌 발생은 추비량이 많을 때 발생량이 높았으며 질소 추비와 에틸렌발생 사이에는 높은 상관관계가 있는 것으로 나타났다.

  • PDF

돌연변이 p53 단백질의 Silencing에 의한 사람유방암세포의 in vivo 항 종양 효과 (Silencing of Mutant p53 Leads to Suppression of Human Breast Xenograft Tumor Growth in vivo)

  • 박원익;박세라;박현주;배윤희;유현수;장혜옥;배문경;배수경
    • KSBB Journal
    • /
    • 제31권1호
    • /
    • pp.52-57
    • /
    • 2016
  • Mutant p53 (R280K) is highly expressed in MDA-MB-231 triple-negative human breast cancer cells. Currently, we reported the role of mutant p53-R280K in mediating the survival of MDA-MB-231 cells in vitro. The present study was undertaken to determine whether mutant p53-R280K affects breast cancer cell growth in vivo. To this end, we used small interfering RNA to knockdown the level of mutant p53-R280K in MDA-MB-231 cells. Silencing of mutant p53-R280K in MDA-MB-231 cells causes substantial tumor regression of established xenografts in vivo. In xenograft model for breast cancer, silencing of mutant p53-R280K in MDA-MB-231 cells significantly inhibited the tumor growth. Moreover, TUNEL assay showed more occurrence of apoptotic cells in mutant p53-R280K silenced tumors compared to control. Our data indicate that mutant p53-R280K has an important role in mediating tumor growth of MDA-MB-231 cells in vivo. Taken together, this study suggests that endogenous mutant p53-R280K could be used as a therapeutic target for breast cancer cells harboring this TP53 missense mutation.

개방화가 한국의 경제성장과 환경오염에 미치는 영향 분석 (An Analysis on the Effects of Economic Growth and Environmental Pollution by Openness)

  • 조성택;조용성
    • 국제지역연구
    • /
    • 제13권3호
    • /
    • pp.269-286
    • /
    • 2009
  • 환경과 개방화 그리고 경제성장에 대한 전통적 주장과 이를 반박하는 주장간의 논쟁은 끝나지 않고 있고, 두 가설을 검증할 수 있는 명확한 이론과 연구가 부재한 상황이다. 본 논문에서는 경제성장, 오염수준, 개방화를 설명하는 변수들을 설정하여 한국에서의 개방화와 경제성장, 오염수준과의 관계를 살펴보고 환경쿠즈네츠 곡선 가설을 검증하였다. 검증결과 한국에서는 개방화가 진전될수록 GDP가 상승하였고 개방화와 경제성장이 환경에 부정적 영향을 준다는 전통적 입장과 달리 환경수준과 개방화 및 경제성장은 정(正)의 관계로 나타났다. 즉, 개방화와 경제성장이 진행될수록 환경수준이 높아졌다. 이는 한국으로 유입되는 외국 자본의 성격이 오염집약적 산업이라기 보다는 친환경기술을 보유한 첨단기술산업임을 시사한다. 결론적으로 우리나라의 경우, 개방화와 외국자본의 유치는 환경오염을 가속화시킨다는 전통적인 가설과 달리 우리 경제를 성장시키고 환경수준을 높이는 효과를 가져온 것으로 추측된다. 아울러 교역이 증가해도 환경수준이 악화되지 않으며, 환경규제가 경제성장의 요인인 개방화를 감소시키지 않는다는 결론을 도출하였다. 이 결과는 수출경쟁력 약화 혹은 경제성장 둔화를 발생시키지 않고도 환경규제를 통해서 오염수준을 개선시킬 수 있음을 시사한다.

Efficacy of Synthesized NO-releasing Nanoparticles on the Germination and Growth of Arabidopsis thaliana

  • Nusrat Jahan Methela;Anjali Pande;Waqas Rahim;Da-Sol Lee;Bong-Gyu Mun;Geun-Mo Lee;Cho Jun-ho;Tiba Nazar Ibrahim Al Azzawi;Hak-Yoon Kim;Byung-Wook Yun
    • 한국작물학회:학술대회논문집
    • /
    • 한국작물학회 2022년도 추계학술대회
    • /
    • pp.159-159
    • /
    • 2022
  • Nitric oxide (NO) is a versatile signaling molecule, which is not only involved in plant growth and development but also regulates biological processes in response to biotic and abiotic stresses. Exogenous application of NO regulates the endogenous level of nitric oxide in response to stress conditions and therefore, NO donors are frequently used for stress alleviation. However, NO has very short half-life along with high reactivity. Therefore, conventional NO donors are often disadvantageous due to the relative instability of NO. On the contrary, development of NO releasing nanoparticles is a potential technique for enhancing the availability of NO in plants. Therefore, our aim was to synthesize such potential NO releasing nanoparticles which may be useful for application in agriculture. We have prepared Chitosan encapsulated S-nitrosoglutathione nanoparticles (GSNONP) and tried it with different concentrations for basic research in Arabidopsis thaliana. Our results suggest that lower concentration of this nanoparticle is highly effective for better growth of plants whereas higher concentration produces toxicity that leads to plant death. We observed better growth of Arabidopsis thaliana at 1µM concentration of the GSNONP compared to free GSNO.

  • PDF

관상식물 삽목발근에 있어서 NAA, IBA 및 Ethychlozate의 발근촉진효과와 그 생리학적연구 (The Promotive Effect of NAA, IBA and Ethychlozate on Rooting Cuttings of Certain Ornamental Plants and Some Physiological Studies.)

  • 정해준;곽병화
    • 자연과학논문집
    • /
    • 제1권
    • /
    • pp.115-198
    • /
    • 1987
  • The present studies were undertaken to elucidate the influence of auxins, auxin-like substance-ethychlozate ("Figaron"),and pH and sort of rooting media on rooted propagation of certainornamental woody plant cuttings, and to see possible changes in internal compositions characterizing after root-promoting treatment as the cutting stage proceeded. The experimental check-up srevealed and summarized as seen in the following;I. Effect of three different auxin treatments on rooting cuttings: 1) Promotive influence of auxin varied according to different concentration levels, hours of dipping treatment of the auxins, and kind of plants. The greatest effect was obtained for Forsythia ksreana with NAA and IBA, for Ligustrurn obtusifolium var. variegatum with NAA and ethychlozate, for Hydrangea macrophylla, Magnolia kobus, and Magnolia liliflora with NAA, lBA and ethychlozate also. The most effective level of the promotive agents was found 200mg/l for NAA, 1000mg/l for IBA, and 200mg/l for ethychlozate. For Weigela florida and Gardenia jasminoides, range of the most effective level was shown relatively wide spread. 2) NAA was more effective at its optimal level of the rooting agent than ethychiozate for Weigela florida, Viburnum awabuki, Forsythia koreana, Acer palmatum 'Nomura', Bouga invillea glabra, Elaeagnus umbellata, Prunus tomentosa, Ligustrum obtusifolium, Pyracantha coccinea, Cestrum noctu rnum, Hydrangea macrophylla, Codiaeum variegatum, Rhododen dron lateritium, and Ilex crenata var. macrophylla, and yet ethychlozate was found either as equally as effective or more so than NAA for Zebrina pendula, Hibiscus syriacus, Fatshedera lizei, Schefflera arboricola, Campsis grandiflo ra, Ixora chinensis, Euonymus japonica, and Magnolia liliflora. On the contrary, no the auxin effect was noted with Lagerstroemia indica, Trachelospermum asiaticum, and Syringa vulgaris. This probably indicates that these species are genetically different for the auxin response.II. Effect of different pH and sorts of cutting media on rooting cuttings: 1) Bougainvillea showed best in rooting for the number and dry weight at pH 6.5, more with ethychlozate than NAA, while Ligustrum did at pH 5.0 more with NAA than ethychlozate. pH 4.0 medium resulted in the best rooting for Rhododendron with NAA, more than ethychlozate. 2) Use of cutting medium with peat: perlite: vermiculite = 1:1:1 showed to give the greatest rooting percent and dry weight, apart from considering the number of roots. This apparently meant the fact that cutting medium has more to do with root growth than root differentiation. Rhododendron yet showed results with cutting media that use of peat: perlite = 2:1 mixed is more effective on rooting than using peat alone.III. Effect of auxinic treatments on rooting cuttings and change in some cutting compositions: 1) Under the climatic conditions of July having temperature $26.3\pm$$2.4^{\circ}C$for cutting bed, new roots of Magnolia started to show up generally 20 days after the cutting was made, whereas Cestrum did much earlier than that, namely 14 days after. 2) Although total carbohydrate content of Magnolia cuttings showed no marked change without auxin treatment, it did so with the treatment, especially 30 days after the start of cutting. Cestrum cuttings demonstrated a gradual in crease in total carbohydrate content as rooting took place, and the content became reduced more with auxin than with out, just about when rooting proceeded to 14 days after the start of cutting. 3) Magnolia generally showed an increase in total nitrogen content as rooting proceeded more, and Cestrum showed a decrease in total nitrogen of cuttings. The auxin treatment exhibited no pertinent relation with change in plant nitro gen when rooting is promoted with auxin treatment. 4) An abrupt drop of total sugar and reducing sugar was noticed as Magnolia rooting started, and this reduction was parti cularly outstanding with auxin treatment. Starch content also was decreased in the later stage of cutting with auxin treatment, and was rather increased without auxin. Although sugar content soon increased as cutting started with auxin treatment in the case of Cestrum, it became reduced after rooting took place. 5) Total phenol content increased with rooting, and this was especially true when rooting started. This increase was reversed somehow regardless of auxin treatment. A decrease in phenol of Magnolia was found more striking with auxin than without in the later stage of the cutting period. 6)Avena coleoptile test for auxin-like substances presented the physiologically active factor is more in easy-to-root Magnolia liliflora than hard-to-root Magnolia kobus, and the activity of auxin-like substances was much increased with auxin treatment. The increase in the growth promoting substances was markedly pronounced when rooting just started. The active growth substances decreased in the later stage of cutting, and certain inhibitory substances started appearing. Cestrum also showed physiologically similar growth promoting substances accompanying auxin-like active substances if auxin is treated, and some strong inhibitory substances seemed to appear in the later stage of cutting. 7) Mung-bean-rooting test indicated biologically that endogenous growth substances in Magnolia all promoted mung-bean rooting, and activity of the growth substances apparently stimulated mung-bean rooting with auxin more than without. Here auxin treatment seemed to give a rise to an increased activity of endogenous growth substances in cuttings. This activity was found much greater with either NAA or IBA than ethychlozate, and showed its peak of the activity when rooting first started taking place. Certain inhibitory substances for Avena coleoptile growth strongly promoted mung-bean rooting, and it was also much like in the case of Cestrum.

  • PDF