• 제목/요약/키워드: cellular structures

검색결과 352건 처리시간 0.026초

Single-Molecule Imaging Reveals the Mechanism Underlying Histone Loading of Schizosaccharomyces pombe AAA+ ATPase Abo1

  • Kang, Yujin;Cho, Carol;Lee, Kyung Suk;Song, Ji-Joon;Lee, Ja Yil
    • Molecules and Cells
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    • 제44권2호
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    • pp.79-87
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    • 2021
  • Chromatin dynamics is essential for maintaining genomic integrity and regulating gene expression. Conserved bromodomain-containing AAA+ ATPases play important roles in nucleosome organization as histone chaperones. Recently, the high-resolution cryo-electron microscopy structures of Schizosaccharomyces pombe Abo1 revealed that it forms a hexameric ring and undergoes a conformational change upon ATP hydrolysis. In addition, single-molecule imaging demonstrated that Abo1 loads H3-H4 histones onto DNA in an ATP hydrolysis-dependent manner. However, the molecular mechanism by which Abo1 loads histones remains unknown. Here, we investigated the details concerning Abo1-mediated histone loading onto DNA and the Abo1-DNA interaction using single-molecule imaging techniques and biochemical assays. We show that Abo1 does not load H2A-H2B histones. Interestingly, Abo1 deposits multiple copies of H3-H4 histones as the DNA length increases and requires at least 80 bp DNA. Unexpectedly, Abo1 weakly binds DNA regardless of ATP, and neither histone nor DNA stimulates the ATP hydrolysis activity of Abo1. Based on our results, we propose an allosteric communication model in which the ATP hydrolysis of Abo1 changes the configuration of histones to facilitate their deposition onto DNA.

Transcriptional Regulatory Role of NELL2 in Preproenkephalin Gene Expression

  • Ha, Chang Man;Kim, Dong Hee;Lee, Tae Hwan;Kim, Han Rae;Choi, Jungil;Kim, Yoonju;Kang, Dasol;Park, Jeong Woo;Ojeda, Sergio R.;Jeong, Jin Kwon;Lee, Byung Ju
    • Molecules and Cells
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    • 제45권8호
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    • pp.537-549
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    • 2022
  • Preproenkephalin (PPE) is a precursor molecule for multiple endogenous opioid peptides Leu-enkephalin (ENK) and Met-ENK, which are involved in a wide variety of modulatory functions in the nervous system. Despite the functional importance of ENK in the brain, the effect of brain-derived factor(s) on PPE expression is unknown. We report the dual effect of neural epidermal growth factor (EGF)-like-like 2 (NELL2) on PPE gene expression. In cultured NIH3T3 cells, transfection of NELL2 expression vectors induced an inhibition of PPE transcription intracellularly, in parallel with downregulation of protein kinase C signaling pathways and extracellular signal-regulated kinase. Interestingly, these phenomena were reversed when synthetic NELL2 was administered extracellularly. The in vivo disruption of NELL2 synthesis resulted in an increase in PPE mRNA level in the rat brain, suggesting that the inhibitory action of intracellular NELL2 predominates the activation effect of extracellular NELL2 on PPE gene expression in the brain. Biochemical and molecular studies with mutant NELL2 structures further demonstrated the critical role of EGF-like repeat domains in NELL2 for regulation of PPE transcription. These are the first results to reveal the spatio-specific role of NELL2 in the homeostatic regulation of PPE gene expression.

Avenanthramide-C Shows Potential to Alleviate Gingival Inflammation and Alveolar Bone Loss in Experimental Periodontitis

  • Su-Jin Kim;Se Hui Lee;Binh Do Quang;Thanh-Tam Tran;Young-Gwon Kim;Jun Ko;Weon-Young Choi;Sun Young Lee;Je-Hwang Ryu
    • Molecules and Cells
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    • 제46권10호
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    • pp.627-636
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    • 2023
  • Periodontal disease is a chronic inflammatory disease that leads to the gradual destruction of the supporting structures of the teeth including gums, periodontal ligaments, alveolar bone, and root cementum. Recently, interests in alleviating symptoms of periodontitis (PD) using natural compounds is increasing. Avenanthramide-C (Avn-C) is a polyphenol found only in oats. It is known to exhibit various biological properties. To date, the effect of Avn-C on PD pathogenesis has not been confirmed. Therefore, this study aimed to verify the protective effects of Avn-C on periodontal inflammation and subsequent alveolar bone erosion in vitro and in vivo. Upregulated expression of catabolic factors, such as matrix metalloproteinase 1 (MMP1), MMP3, interleukin (IL)-6, IL-8, and COX2 induced by lipopolysaccharide and proinflammatory cytokines, IL-1β, and tumor necrosis factor α (TNF-α), was dramatically decreased by Avn-C treatment in human gingival fibroblasts and periodontal ligament cells. Moreover, alveolar bone erosion in the ligature-induced PD mouse model was ameliorated by intra-gingival injection of Avn-C. Molecular mechanism studies revealed that the inhibitory effects of Avn-C on the upregulation of catabolic factors were mediated via ERK (extracellular signal-regulated kinase) and NF-κB pathway that was activated by IL-1β or p38 MAPK and JNK signaling that was activated by TNF-α, respectively. Based on this study, we recommend that Avn-C may be a new natural compound that can be applied to PD treatment.

Current strategies using 3D organoids to establish in vitro maternal-embryonic interaction

  • Islam Mohamed Saadeldin;Seif Ehab;Ahmed Elsayed Noreldin;Ayman Abdel-Aziz Swelum;Seonggyu Bang;Hyejin Kim;Ki Young Yoon;Sanghoon Lee;Jongki Cho
    • Journal of Veterinary Science
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    • 제25권3호
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    • pp.40.1-40.19
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    • 2024
  • Importance: The creation of robust maternal-embryonic interactions and implantation models is important for comprehending the early stages of embryonic development and reproductive disorders. Traditional two-dimensional (2D) cell culture systems often fail to accurately mimic the highly complex in vivo conditions. The employment of three-dimensional (3D) organoids has emerged as a promising strategy to overcome these limitations in recent years. The advancements in the field of organoid technology have opened new avenues for studying the physiology and diseases affecting female reproductive tract. Observations: This review summarizes the current strategies and advancements in the field of 3D organoids to establish maternal-embryonic interaction and implantation models for use in research and personalized medicine in assisted reproductive technology. The concepts of endometrial organoids, menstrual blood flow organoids, placental trophoblast organoids, stem cell-derived blastoids, and in vitro-generated embryo models are discussed in detail. We show the incorportaion of organoid systems and microfluidic technology to enhance tissue performance and precise management of the cellular surroundings. Conclusions and Relevance: This review provides insights into the future direction of modeling maternal-embryonic interaction research and its combination with other powerful technologies to interfere with this dialogue either by promoting or hindering it for improving fertility or methods for contraception, respectively. The merging of organoid systems with microfluidics facilitates the creation of sophisticated and functional organoid models, enhancing insights into organ development, disease mechanisms, and personalized medical investigations.

Internet of Things for in Home Health based Monitoring System: Modern Advances, Challenges and Future Directions

  • Omer Iqbal;Tayyeba Iftakhar;Saleem Zubair Ahmad
    • International Journal of Computer Science & Network Security
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    • 제24권8호
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    • pp.191-204
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    • 2024
  • IOT has carried out important function in converting the traditional fitness care corporation. With developing call for in population, traditional healthcare structures have reached their outmost functionality in presenting sufficient and as plenty as mark offerings. The worldwide is handling devastating developing antique population disaster and the right want for assisted-dwelling environments is turning into inevitable for senior citizens. There furthermore a determination by means of the use of way of countrywide healthcare organizations to increase crucial manual for individualized, right blanketed care to prevent and manipulate excessive coronial situations. Many tech orientated packages related to Health Monitoring have been delivered these days as taking advantage of net boom everywhere on globe, manner to improvements in cellular and in IOT generation. Such as optimized indoor networks insurance, community shape, and fairly-low device fee performances, advanced tool reliability, low device energy consumption, and hundreds higher unusual common usual performance in network safety and privacy. Studies have highlighted fantastic advantages of integrating IOT with health care location and as era is improving the rate also cannot be that terrific of a problem. However, many challenges in this new paradigm shift notwithstanding the fact that exist, that need to be addressed. So the out most purpose of this research paper is 3 essential departments: First, evaluation of key elements that drove the adoption and boom of the Internet of factors based totally domestic some distance off monitoring; Second, present fashionable improvement of IOT in home a long manner off monitoring shape and key building gadgets; Third, communicate future very last effects and distinct guidelines of such type a long way off monitoring packages going ahead. Such Research is a wonderful manner in advance now not outstanding in IOT Terminology but in standard fitness care location.

Dichlorvos가 흰쥐 심근의 미세구조에 미치는 영향 (A Study on the Ultrastructural Changes of Cardiac Muscle in Dichlorvos Treated Albino Rat)

  • 백태경;이화모;정호삼
    • Applied Microscopy
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    • 제24권3호
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    • pp.23-33
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    • 1994
  • It is well known that dichlorvos (DDVP), an organophosphate insecticide in common use, is so easily and rapidly hydrolyzed and excreted that it has usually little toxic effect on human body. In these days, however, it is widely used as an industrial and domestic insecticide and as an anthelmintic agent for animals, so that the accident of chemical poisoning occurs frequently. DDVP acts as a powerful inhibitor of carboxylic esterase, which can cause accumulation of acetylcholine at the synapses so paralysis of muscle and the transmission failure in cholinergic synapses dueing to desensitization of acetylcholin receptor may occure. Moreover accumulation of the acetylcholine brings about the elevation of the cyclic-AMP, which alters the cellular metabolisms of nucleic acid, carbohydrate, protein and lipid. Present study has undertaken to investigate the cardiotoxic effect of DDVP by electron microscopic study. A total of 30 Sprague-Dawley strain rats, weighing about 250gm were used as experimental animals. 2mg/kg/day of DDVP is intraperitonealy injected 3 times with intervals of every other day. On 1 day, 3 days, 5 days, 7 days and 14 days after drug administration, the animals were sacrified by cervical dislocation. Left ventricular cardiac muscles were resected and sliced into $1mm^3$. The specimens were embedded with Epon 812 and prepared by routine methods for electron microscopical observation. All preparations were stained with lead citrate and uranyl acetate and then observed with Hitachi-600 transmission electron microscope. The results were as follows: 1. In the cardiac muscle of DDVP treated rats, mitochondria with disorganized double membrane and mitochondrial crista, and vacuole formation in mitochondrial matrix were observed. But structures of mitochondria were recovered to normal in 14 days group. 2. In the cardiac muscle of DDVP treated rats, cisternae of sarcoplasmic reticulum were dilated and sacculated. But these changes were recovered to normal in 14 days group. 3. In the cardiac muscle of DDVP treated rats, glycogen particles around damaged myofibrils were decreased. But amount of glycogen particles were restored in 14 days group. 4. In the cardiac muscle of DDVP treated rats, disruption and discontinuation of myofilaments and disorganization of Z-disc were observed. But the structures of myofibrils were recovered to normal in 14 days group. It is consequently suggested that DDVP would induce the reversible degenerative changes on the ultrastructures in cardiac muscle of rat.

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산민달팽이 (Incilaria fruhstorferi) 눈의 미세구조 (Ultrastructure of the Eye in the Snail, Incilaria fruhstorferi)

  • 장남섭;한종민;이광주
    • Applied Microscopy
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    • 제28권3호
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    • pp.363-377
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    • 1998
  • After the investigation on the eye of Incilaria fruhstorieri with light and electron microscopes, the following results were obtained. The eye of Incilaria fruhstorferi comprises cornea, lens, vitreous body, retina, and optic nerve inward from the outside. Cornea is composed of squamous, cuboid, columnar and irregular cells, which appear to be light due to their low electron density. In their cytoplasms, glycogen granules, multivesicular body, and nucleus were observed. Vitreous body, located behind non-cellular transparent lens, is filled with long and short microvilli protruding from the retinal epithelia. Retinal epithelium, the organ to perceive objects, is divided into four parts; microvillar layer pigment layer, nuclear layer, and neutrophils layer, from the apical portion. Microvillar layer consists of the type-I photoreceptor cells and pigmented granule cells. In the apical portion of their cytoplasms, long microvilli (length, $19{\mu}m$) , short microvilli (length, $8{\mu}m$), and rolled microvilli grow thick in the irregular and mixed forms. Photoreceptor cells are classified into type-I and type-II, according to their structures. The type-I cell has the apical portion rising roundly like a fan and the lower part which looks like the helve of a fan. In the cytoplasm of the apical portion, there are clear vesicles, cored vesicles, ovoid mitochondria, and microfilaments, and in the cytoplasm of the lower part, photic vesicles with their diameters about 60nm aggregate densely. The type-II photoreceptor cell, located at the lower end of the type-I cells, has a very large ovoid nucleus 3nd no microvilli. In the cytoplasm of the type-II cell, the photic vesicles with sizes 60nm aggregate more densely than in the cytoplasm of the type-I cell. Pigmented cells are classified into type-A and type-B, according to their structures. The type-A is identified to be a large cell containing round granules (diameter, $0.5{\mu}m$) of very high electron density, while the type-B is identified as a small cell where the irregular granules (diameter, $0.6{\mu}m$) of a little lower electron density amalgamate. Nuclear layer ranges from the bottom of pigment layer to the top of the capsule, and contains three kinds of nuclei (nuclei of the type-II photoreceptor cell, pigmented granule cell, and accessory neuron). The capsules covering the outmost part of the eyeball are composed of collagenous fiber and three longitudinal muscle layers (the thickness of each longitudinal muscle layer, $0.4{\mu}m$) and thick circular muscle layer (thickness, $0.3{\mu}m$). Around the capsules, there is a neurophile layer consisting of neurons and nerve fibers. Each neuron has a relatively large ovoid nucleus for its cytoplasm, and in the karyosome, large lumps of keterochromatin form a wheel nucleus.

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열저항 효과를 고려한 $9\%$ 니켈강재식 LNG 저장탱크의 누설 안전성에 관한 연구 (On the Leakage Safety Analysis of $9\%$ Nickel Type LNG Storage Tank with Thermal Resistance Effects)

  • 김청균;조승현;서홍석;홍성호;이승림;김영규;권부길
    • 한국가스학회지
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    • 제9권1호
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    • pp.1-8
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    • 2005
  • 본 연구에서는 $9\%$ 니켈강재식 LNG저장탱크에 대한 누설 안전성을 여러 가지 단열재와 코너 프로텍션, PC 구조물 사이에 존재하는 열저항 평형온도 효과를 고려하여 유한요소법으로 해석하였다. FEM 계산결과에 따르면, 파이버 글라스 블랑켓, 펄라이트 파우더, 셀루러 글라스 단열재 등은 재질의 취약한 강도 때문에 누설 LNG에 의한 하중이 가해지면 단열재 자체가 파손되므로 누설 안전성을 보장할 수 없게 된다. 그러나, 내부탱크와 단열재가 동시에 파손되어도 $9\%$ 니켈강재로 제작된 코너 프로텍션(CP) 예응력 콘크리트(PC)구조물의 외부탱크는 LNG의 복합하중에 대하여 강도 안전성을 확보하고 있으므로, 누설 LNG를 최소한 10일 정도는 안전하게 체류시킬 수 있다. 따라서, $9\%$ 니켈강제식 LNG 저장탱크 시스템은 이들 두 가지 구조물에 의해 누설 안전성이 확보된다.

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Induction of DNA Damage in L5178Y Cells Treated with Gold Nanoparticle

  • Kang, Jin-Seok;Yum, Young-Na;Kim, Joo-Hwan;Song, Hyun-A;Jeong, Jin-Young;Lim, Yong-Taik;Chung, Bong-Hyun;Park, Sue-Nie
    • Biomolecules & Therapeutics
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    • 제17권1호
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    • pp.92-97
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    • 2009
  • As nanomaterials might enter into cells and have high reactivity with intracellular structures, it is necessary to assay possible genotoxic risk of them. One of these approaches, we investigated possible genotoxic potential of gold nanoparticle (AuNP) using L5178Y cells. Four different sizes of AuNP (4, 15, 100 or 200 nm) were synthesized and the sizes and structures of AuNP were analyzed using transmission electron microscopy (TEM), scanning electron microscopy (SEM) and stability was analyzed by a UV/Vis. Spectrophotometer. Cytotoxicity was assessed by direct cell counting, and cellular location was detected by dark field microscope at 6, 24 and 48 h after treatment of AuNP. Comet assay was conducted to examine DNA damage and tumor necrosis factor (TNF)-${\alpha}$ mRNA level was assay by real-time reverse transcription polymerase chain reaction. Synthetic AuNP (4, 50, 100 and 200 nm size) had constant characteristics and stability confirmed by TEM, SEM and spectrophotometer for 10 days, respectively. Dark field microscope revealed the location of AuNP in the cytoplasm at 6, 24 and 48 h. Treatment of 4 nm AuNP induced dose and time dependent cytotoxicity, while other sizes of AuNP did not. However, Comet assay represented that treatment of 100 nm and 200 nm AuNP significantly increased DNA damage compared to vehicle control (p <0.01). Treatment of 100 nm and 200 nm AuNP significantly increased TNF-${\alpha}$ mRNA expression compared to vehicle control (p<0.05, p<0.01, respectively). Taken together, AuNP induced DNA damage in L5178Y cell, associated with induction of oxidative stress.

생체활성 각질층 지질 - 아토피 피부염 관리를 중심으로 - (Stratum Corneum Lipids as Bioactive Materials for Atopic Dermatitis)

  • 박병덕;염종경;안성구;이승헌
    • 대한화장품학회지
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    • 제30권3호
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    • pp.345-352
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    • 2004
  • 아토피 피부염을 설명하는 데는 두 가지 패러다임이 있는데, 첫 번째는 outside-inside paradigm이고 두 번째는 inside-ouside paradigm이다. Outside-inside paradigm에 의하면 아토피 피부염을 치료하기 위한 가장 좋은 방법은 피부 장벽 기능을 회복시키는 것이다. 장벽 기능은 각질층의 특징적인 구조에 의해 유지되는데, 각질층은 층상구조의 inter-cellular lipids와 corneocyte로 구성되어 있다. 아토피 피부염 환자, 층판상 어린선 환자의 각질층 내 층상구조는 hexagonal 구조가 많이 존재하고 있음을 보였으며, 이는 Ceramide 1 타입과 long chain fatty acid의 감소 때문이라고 보여진다. 이러한 이유에서 라멜라구조를 가지며 intercellular long periodicity phase 기능을 복원할 수 있는 보습제는 각질층의 intercellular lipid의 층상구조를 복원시킬 수 있을 것이다. 또한 세라마이드와 유사세라마이드를 함유한 보습제는 손상된 피부장벽, 피부질환, 아토피 피부염을 위한 유용한 치료제로 사용할 수 있다. Inside-outside paradigm에 따르면, 아토피 피부염 등이 보조 T cell, lg E, eosinophil 등을 포함한 면역반응과 관계되는데, 특히 Th1/Th2 imbalance의 복원이 아토피 피부염을 치료하는데 효과적일 것이다. 현재 여러 종류의 면역억제제가 소개되고 있지만, 이들은 고유 면역기능을 감소시킬 우려를 가지고 있다. 따라서, 세라마이드 대사산물인 SPC와 S1P는 면역조절 기능 및 상처치유의 기능을 가짐으로써 향후 관심이 집중될 것이다.