• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.553-553
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• 2012

The artificial shells of hard inorganic nanocomposites on individual cells would protect the cells physically and chemically, and control cell division. These emerging properties could be combined with cell-surface functionalizations for applications to cell-based sensors and assays as well as for fundamental studies on single-cell biology. In this work, individual Chlorella cells were encapsulated within a silica/titania nanocomposite shell in a biocompatible fashion that utilized a designed peptide, RKKRKKRKKRKKDDDDDDDD, as a catalytic template for formation of both $SiO_2$ and $TiO_2$ on the cell surface. The cell viability was maintained, and the division of the encapsulated Chlorella cells was controlled. The cell viability was enhanced compared with the $TiO_2$-shell formation. In addition, the incorporation of $TiO_2$ to the shell made it possible to anchor the ligands of interest to the shell via catechol chemistry. All in all, the combination of biological $SiO_2$ and abiolgical $TiO_2$ for the shell formation gave more tunability of the artificial shells compared with the $SiO_2$ or $TiO_2$ shells only.

• Molecules and Cells
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• 제44권8호
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• pp.602-612
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• 2021

DNA methylation is an important epigenetic mechanism affecting genome structure, gene regulation, and the silencing of transposable elements. Cell- and tissue-specific methylation patterns are critical for differentiation and development in eukaryotes. Dynamic spatiotemporal methylation data in these cells or tissues is, therefore, of great interest. However, the construction of bisulfite sequencing libraries can be challenging if the starting material is limited or the genome size is small, such as in Arabidopsis. Here, we describe detailed methods for the purification of Arabidopsis embryos at all stages, and the construction of comprehensive bisulfite libraries from small quantities of input. We constructed bisulfite libraries by releasing embryos from intact seeds, using a different approach for each developmental stage, and manually picking single-embryo with microcapillaries. From these libraries, reliable Arabidopsis methylome data were collected allowing, on average, 11-fold coverage of the genome using as few as five globular, heart, and torpedo embryos as raw input material without the need for DNA purification step. On the other hand, purified DNA from as few as eight bending torpedo embryos or a single mature embryo is sufficient for library construction when RNase A is treated before DNA extraction. This method can be broadly applied to cells from different tissues or cells from other model organisms. Methylome construction can be achieved using a minimal amount of input material using our method; thereby, it has the potential to increase our understanding of dynamic spatiotemporal methylation patterns in model organisms.

• BMB Reports
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• 제36권5호
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• pp.499-504
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• 2003

There has been increasing interest in studying the various effects of organophosphate insecticides in humans and experimental animals. Only a few data are available on the effect of the organophosphate insecticide, diazinon, on lipid metabolism. The aim of this study was to evaluate the effect of diazinon on plasma lipid constituents in mammalian animals. The plasma levels of total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglycerides (TG), and phospholipids (PL) were measured in albino rats that were orally treated with a single dose of diazinon at a level of $LD_{50}$ or with repeated daily doses at the levels of $\frac{1}{2}$, $\frac{1}{8}$, and $\frac{1}{32}$ $LD_{50}$ for 2, 8, and 32 days, respectively. After a 24 h post-treatment with a single $LD_{50}$ dose of diazinon, TC was not significantly changed, the HDL-C and PL levels were significantly decreased, but the LDL-C and TG levels were significantly increased. Separate daily oral administrations of diazinon at $\frac{1}{2}$ $LD_{50}$, $\frac{1}{8}$ $LD_{50}$, and $\frac{1}{32}$ $LD_{50}$ doses resulted in a significant decrease in HDL-C and PL, with no significant change in TG. The LDL-C levels were significantly increased and TC showed no significant change with $\frac{1}{2}$ $LD_{50}$ and $\frac{1}{32}$$LD_{50}$ doses of diazinon, whereas a significant decrease in the levels of TC, HDL-C, as well as LDL-C, was observed with the $\frac{1}{8}$ $LD_{50}$ dose. These data suggest that diazinon may interfere with lipid metabolism in mammals.

• Reproductive and Developmental Biology
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• 제39권4호
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• pp.105-115
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• 2015

Toll-like receptor 7 (TLR7) is critical for the triggering of innate immune response by recognizing the conserved molecular patterns of single-stranded RNA (ssRNA) viruses and mediated antigenic adaptive immunity. To understand how TLR7 distinguish pathogen-derived molecular patterns from the host self, it is essential to be able to identify TLR7 receptor interaction interfaces, such as active sites or R848-agonist binding sites. The functional interfaces of TLR7 can serve as targets for structure-based drug design in studying the TLR7 receptor's structure-function relationship. In contrast to mammalian TLR7, chicken TLR7 (chTLR7) is unknown for its important biological function. Therefore, it has been targeted to mediate contrasting evolutionary patterns of positive selection into non-synonymous SNPs across eleven species using TLR7 conservation patterns (evolutionary conserved and class-specific trace residues), where protein sequence differences to the TLR7 receptors of interest record mutation that have passed positive section across the species. In this study, we characterized the Lys609 residue on chTLR7-ECD homodimer interfaces to reflect the current tendency of evolving positive selection to be transfer into a stabilization direction of the R848-agonist/chTLR7-ECDs complex under the phylogenetically variable position across species and we suggest a potential indicator for contrasting evolutionary patterns of both the species TLR-ECDs.

• The Korean Journal of Physiology and Pharmacology
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• 제21권3호
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• pp.327-334
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• 2017

Epidemiologic interest in particulate matter (PM) is growing particularly because of its impact of respiratory health. It has been elucidated that PM evoked inflammatory signal in pulmonary epithelia. However, it has not been established $Ca^{2+}$ signaling mechanisms involved in acute PM-derived signaling in pulmonary fibroblasts. In the present study, we explored dust particles PM modulated intracellular $Ca^{2+}$ signaling and sought to provide a therapeutic strategy by antagonizing PM-induced intracellular $Ca^{2+}$ signaling in human lung fibroblasts MRC5 cells. We demonstrated that PM10, less than $10{\mu}m$, induced intracellular $Ca^{2+}$ signaling, which was mediated by extracellular $Ca^{2+}$. The PM10-mediated intracellular $Ca^{2+}$ signaling was attenuated by antioxidants, phospholipase blockers, polyADPR polymerase 1 inhibitor, and transient receptor potential melastatin 2 (TRPM2) inhibitors. In addition, PM-mediated increases in reactive oxygen species were attenuated by TRPM2 blockers, clotrimazole (CLZ) and N-(p-amylcinnamoyl) anthranilic acid (ACA). Our results showed that PM10 enhanced reactive oxygen species signal by measuring DCF fluorescence and the DCF signal attenuated by both TRPM2 blockers CLZ and ACA. Here, we suggest functional inhibition of TRPM2 channels as a potential therapeutic strategy for modulation of dust particle-mediated signaling and oxidative stress accompanying lung diseases.

• Journal of Microbiology and Biotechnology
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• 제27권2호
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• pp.357-364
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• 2017

In this study, we aimed to generate a series of versatile tagging plasmids that can be used in diverse molecular biological studies of the fungal pathogen Cryptococcus neoformans. We constructed 12 plasmids that can be used to tag a protein of interest with a GFP, mCherry, $4{\times}FLAG$, or $6{\times}HA$, along with nourseothricin-, neomycin-, or hygromycin-resistant selection markers. Using this tagging plasmid set, we explored the adenylyl cyclase complex (ACC), consisting of adenylyl cyclase (Cac1) and its associated protein Aca1, in the cAMP-signaling pathway, which is critical for the pathogenicity of C. neoformans. We found that Cac1-mCherry and Aca1-GFP were mainly colocalized as punctate forms in the cell membrane and non-nuclear cellular organelles. We also demonstrated that Cac1 and Aca1 interacted in vivo by co-immunoprecipitation, using $Cac1-6{\times}HA$ and $Aca1-4{\times}FLAG$ tagging strains. Bimolecular fluorescence complementation further confirmed the in vivo interaction of Cac1 and Aca1 in live cells. Finally, protein pull-down experiments using $aca1{\Delta}$::ACA1-GFP and $aca1{\Delta}$::ACA1-GFP $cac1{\Delta}$ strains and comparative mass spectrometry analysis identified Cac1 and a number of other novel ACC-interacting proteins. Thus, this versatile tagging plasmid system will facilitate diverse mechanistic studies in C. neoformans and further our understanding of its biology.

• International Journal of Industrial Entomology and Biomaterials
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• 제32권1호
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• pp.12-25
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• 2016

Recently, research investment in the improvement of food safety as a food source and specializing of nutritional source of edible insects is being actively conducted. Cricket especially has been attracting considerable interest in entomophagy; however, research on the safety assessment of cricket is limited. This study investigated the effects of cricket ethanol extract when orally administrated in Sprague-Dawley rats. Here, we performed a 4 wk repeated oral dose toxicity test in Sprague-Dawley rats following the Organization for Economic Cooperation and Development test guidelines 407 under Good Laboratory Practice regulation. Rats were randomly allocated 4 groups: vehicle control, 250, 500, 1,000 mg/kg test groups and administrated based on body weight for 28 d. The animals were observed for mortalities and clinical signs, body weight changes, food and water consumption. At the end of treatment period, blood and urine were collected and analyzed. Subsequently, the animals were sacrificed and subjected to gross pathological examination and organ weight measurement. The organs were preserved for histopathological examination. The results showed that there were no systemic toxicological effects related with the cricket ethanol extract in the 4 wk oral repeated dose toxicity study. It is considered that NOAEL of cricket ethanol extract is greater than 1,000 mg/kg/d and there was no target organ detected.

• Applied Microscopy
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• 제42권2호
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• pp.95-103
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• 2012

연잎효과는 연꽃의 잎에서 규명된 현상으로 표피세포에서 기원하는 미세구조에 의해 물방울이 잎 표면이나 내부조직에 침투하지 않고 경사면으로 흘러내리며 표면 위 먼지나 이물질을 함께 떨어지게 한다. 잎 표면을 항상 깨끗한 상태로 유지하는 자기정화 능력인 연잎효과에 대해서는 여러 영역에서 연구되고 다방면으로 응용되고 있으나 구조적인 측면에서 연잎을 생장단계별 또는 표피조직 부위별로 비교 조사한 연구는 거의 없는 실정이다. 이에 본 연구에서는 연잎과 줄기를 대상으로 생장단계별, 부위별 표피조직의 미세 표면구조를 연구하여 연잎효과 표면 특성을 조사하였다. 본 연구에서 조사된 연잎효과는 미세돌기와 왁스결정체가 발달한 잎의 상피조직에서만 나타나고, 왁스결정체만 발달한 하피 및 줄기의 표피조직에서는 확인되지 않았다. 이는 미세돌기의 발달이 연잎효과를 나타내는데 가장 중요한 요인이고, 왁스결정체가 돌기표면 위에 축적되면 연잎효과는 더 증가하는 것으로 밝혀졌다.

• Journal of Plant Biotechnology
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• 제43권4호
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• pp.411-416
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• 2016

NGS 기술은 전체 게놈 시퀀싱 및 reference 게놈에 alignment에 의해 돌연변이 표현형에 관련된 돌연변이 식별에 이용한다. 그러나 품종 및 계통들을 resequence 하였을 경우 기존의 reference 게놈에 구조적 변이가 보이며, reference와 맞지 않는 게놈지역에서 돌연변이들은 단순한 alignment로 찾을 수 없다. 본 리뷰에서는 NGS 기술을 이용하여 돌연변이체로부터 변이 관련 유전자를 식별하는 MutMap, MutMap-Gap 및 MutMap+ 방법을 기술하였고 지금까지의 연구현황에 대해 기술하였다. 아울러 이들 방법은 nucleotide-binding site-leucine rich repeat (NBS-LRR) 그룹들의 병 저항성 유전자와 같이 구조적 변이를 가진 유전자를 분리하는 등 유용성에 대해 고찰하였다.

• 전기화학회지
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• 제7권2호
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• pp.108-123
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• 2004

최근 근접장 광학주사현미경 (NSOM)을 이용한 재료의 표면 및 구조 분석은 생물학에서 재료과학에까지 광범위하게 응용되고 있다. 본 총설에서는 기존의 NSOM을 여러가지 현미경법 (광학, 형광, 전자 및 전기화학 현미경 관찰법)과 접목하여 구성한 다기능 NSOM (multi-functional NSOM, mf-NSOM)을 이용, 나노 재료의 고분해능 이미징에 대한 원리와 응용을 고찰하였다. 본 mf-NSOM 기술을 이용하여 실제로 Al합금 및 다결정 Ti 표면에서의 공식 (pitting)을 일으키는 취약 지역을 광학적으로 분석한 결과를 기술하였다. 또한, mf-NSOM과 레이저 기술을 통해 나노 Ag 입자를 형성하고 실시간 분석한 연구결과에 대해서도 소개하고자 한다.