• Fisheries and Aquatic Sciences
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• 제17권3호
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• pp.377-380
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• 2014

RNA interference (RNAi)-mediated transcriptional knock-down of Crassostrea gigas big defensin 1 and 2 genes (Cg-BigDef1 and Cg-BigDef2) was investigated. The cDNA sequences of Cg-BigDef1 and Cg-BigDef2 were identical, excluding an additional fragment of 20 nucleotides in Cg-BigDef1; thus, a long double-stranded RNA (dsRNA) targeting the mRNA of Cg-BigDef2 effectively downregulated both Cg-BigDef2 and Cg-BigDef1. In addition, long dsRNA targeting green fluorescent protein (GFP) did not affect transcription of the two big defensin genes. These results suggest that the transcriptional downregulation of Cg-BigDef1 and Cg-BigDef2 was mediated by sequence-specific RNA interference (RNAi). Despite injection of long dsRNA targeting Cg-BigDef2 into only the adductor muscle, knock-down of Cg-BigDef1 and Cg-BigDef2 was observed in the adductor muscle, hemocytes, mantle, and gills, suggestive of systemic spread of RNAi in C. gigas. Furthermore, the inhibitory effect of dsRNA persisted until 72 h post-injection, indicative of a long-lasting RNAi-mediated knock-down of target genes.

• The Plant Pathology Journal
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• 제29권1호
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• pp.17-30
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• 2013

Barley stripe mosaic virus (BSMV) induces massive actin filament thickening at the infection front of infected Nicotiana benthamiana leaves. To determine the mechanisms leading to actin remodeling, fluorescent protein fusions of the BSMV triple gene block (TGB) proteins were coexpressed in cells with the actin marker DsRed: Talin. TGB ectopic expression experiments revealed that TGB3 is a major elicitor of filament thickening, that TGB2 resulted in formation of intermediate DsRed:Talin filaments, and that TGB1 alone had no obvious effects on actin filament structure. Latrunculin B (LatB) treat-ments retarded BSMV cell-to-cell movement, disrupted actin filament organization, and dramatically decreased the proportion of paired TGB3 foci appearing at the cell wall (CW). BSMV infection of transgenic plants tagged with GFP-KDEL exhibited membrane proliferation and vesicle formation that were especially evident around the nucleus. Similar membrane proliferation occurred in plants expressing TGB2 and/or TGB3, and DsRed: Talin fluorescence in these plants colocalized with the ER vesicles. TGB3 also associated with the Golgi apparatus and overlapped with cortical vesicles appearing at the cell periphery. Brefeldin A treatments disrupted Golgi and also altered vesicles at the CW, but failed to interfere with TGB CW localization. Our results indicate that actin cytoskeleton interactions are important in BSMV cell-to-cell movement and for CW localization of TGB3.

• Journal of Microbiology and Biotechnology
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• 제30권9호
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• pp.1430-1435
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• 2020

Bacterial cellulose (BC) has outstanding physical and chemical properties, including high crystallinity, moisture retention, and tensile strength. Currently, the major producer of BC is Komagataeibacter xylinus. However, due to limited tools of expression, this host is difficult to engineer metabolically to improve BC productivity. In this study, a regulated expression system for K. xylinus with synthetic ribosome binding site (RBS) was developed and used to engineer a BC biosynthesis pathway. A synthetic RBS library was constructed using green fluorescent protein (GFP) as a reporter, and three synthetic RBSs (R4, R15, and R6) with different strengths were successfully isolated by fluorescence-activated cell sorting (FACS). Using synthetic RBS, we optimized the expression of three homologous genes responsible for BC production, pgm, galU, and ndp, and thereby greatly increased it under both static and shaking culture conditions. The final titer of BC under static and shaking conditions was 5.28 and 3.67 g/l, respectively. Our findings demonstrate that reinforced metabolic flux towards BC through quantitative gene expression represents a practical strategy for the improvement of BC productivity.

• 생명과학회지
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• 제28권2호
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• pp.162-169
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• 2018

세포기질에 존재하는 많은 종류의 단백질들은 N-말단에 존재하는 짧은 펩타이드들에 의해서 trans-golgi network(TGN)의 세포질쪽 막에 타기팅될때 중요한 역할을 수행한다고 보고되고 있다. 본 연구실에서도 이전에 바다달팽이인 군소에서 클로닝된 phosphodiesterase 4의 long-form의 경우 N-말단에 존재하는 20개의 아미노산 서열만으로도 충분히 HEK293T세포의 TGN의 세포질막에 타기팅 되게 하며, 이 펩타이드가 sulfatide와 PI4P에 결합성이 있다는 사실을 in vitro에서 확인하였다. 그래서, 본 연구에서는 sulfatide결합성과 TGN막 타기팅과의 연관성을 연구하고자 하였다. 이를 위해 우선 이전 문헌을 통해 sulfatide결합 펩타이드를 찾았고, 이를 GFP단백질과 융합하여 재조합 단백질(mHSBP-EGFP)을 만들어 세포내 타기팅을 실험해 보았다. 이러한 연구를 수행한 결과, mHSBP-EGFP가 HEK293T세포에서 TGN에 타기팅 되고, sulfatide결합이 망가진 돌연변이는 타기팅이 사라짐을 확인하였다. 또한, mHSBP-EGFP가 TGN에 타기팅 되는 것은 억제제인 antimycin A와 PAO와 adenosine에 의해 억제됨을 확인할 수 있었다. 이러한 사실을 통해, PAO와 adenosine에 민감한 인산화효소들, 그중에 PI4KII의 활성이 mHSBP-EGFP를 TGN으로 위치하게 하는데 중요한 역할을 수행한다고 추론할 수 있다.

• Journal of Pharmaceutical Investigation
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• 제31권4호
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• pp.241-256
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• 2001

Alginate microspheres, containing fluorescein isothiocyanate-bovine serum albumin (FITC-BSA) or green fluorescent protein (GFP) were prepared and used as a model drug to develop the oral vaccine delivery system. The alginate microspheres were coated with poly-L-lysine or chitosan. Two methods, w/o-emulsion and spray, were used to prepare alginate microspheres. To optimize preparation conditions, effects of several factors on the particle size and particle morphology of microsphere, and loading efficiency of model antigen were investigated. In both preparation methods, the particle size and the loading efficiency were enhanced when the concentration of sodium alginate increased. In the w/o-emulsion preparation method, as the concentration of Span 80 was increased from 0.5% to 2%, the particle size was decreased, but the loading efficiency was increased. The higher the emulsification speed was, the smaller the particle size and loading efficiency were. The concentration of calcium chloride did not show any effect on the particle size and loading efficiency. In the spray preparation method, the particle size was increased as the nozzle pressure $(from\;1\;kgf/m^2\;to\;3\;kgf/m^2)$ and spray rate was raised. Increasing calcium chloride concentration (<7%) decreased the particle size, in contrast to no effect of calcium chloride concentration on the w/o-emulsion preparation method. Alginate microspheres prepared by two methods were different in the particle size and loading efficiency, the particle size of microspheres prepared by the spray method was about $2-6\;{\mu}m$, larger than that prepared by the w/o emulsion method $(about\;2{\mu}m)$, and the loading efficiency was also higher with spray method. Furthermore, drying process for the microspheres prepared by the spray was simpler and easier, compared with the w/o emulsion preparation. Therefore, the spray method was chosen to prepare alginate microspheres for further experiments. Release pattern of FITC-BSA in alginate microspheres was evaluated in simulated intestinal fluid and PBS (phosphate buffered saline). Dissolution rate of FITC-BSA from alginate/chitosan microsphere was lower than that from alginate microsphere and alginate/poly-L-lysine microsphere. By confocal laser scanning microscope, it was revealed that alginate/FITC-poly-L-lysine microspheres were present in close apposition epithelium of the Peyer's patches of rabbits following inoculation into lumen of intestine, which proved that microspheres could be taken up by Peyer's patch. In conclusion, it is suggested that alginate microsphere prepared by spray method, showing a particle size of & $10\;{\mu}m$ and a high loading efficiency, can be used as a model drug for the development of oral vaccine delivery system.

• Journal of Animal Science and Technology
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• 제50권6호
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• pp.807-818
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• 2008

본 시험은 외인성 유산균의 장내 생존성과 유산균 첨가수준 및 급여빈도가 육계 생산성에 미치는 영향을 조사함으로써 유산균의 적정 급여방법을 구명하기 위하여 실시되었다. 시험 1에서는 외인성 유산균의 장내 체류 시간을 조사하기 위하여 5주령 육계(Abor Acre) 100수에서 사료 내 1.0×104cfu/g 수준으로 GFP 유전자가 도입된 유산균을 급여하였다. GFP 유산균을 육계에게 급여한 결과 급여 3일차까지는 일정한 수 이상의 유산균이 관찰되었으나 그 이후 급격히 감소되는 것을 확인하였다. 시험 2에서는 유산균 적정 첨가 수준을 구명하기 위하여 1일령 육계 수평아리(Abor Acre) 480수를 공시하여 4처리 4반복, 반복당 30수씩 임의 배치하여 5주간 사양시험을 실시하였다. 시험처리는 항생제 무첨가구를 대조구로 하였으며, 음수 내 유산균을 5.0×10cfu/mL, 5.0×103 cfu/mL, 및 5.0×105cfu/mL 수준으로 첨가하여 유산균 처리구를 두었다. 5주 종료 체중은 5.0×103cfu/mL 첨가 급여시 1,919g으로 가장 높았으며(P<0.05), 증체량은 5.0×103cfu/mL 및 5.0×105cfu/mL 첨가 급여시 대조구에 비해 유의하게 증가하였다(P<0.05). 회장 및 맹장 내 유산균 수에 있어서는 첨가수준별로 차이는 있었으나 유산균 첨가 급여시 회장 및 맹장 내 유산균 수가 유의하게 증가하였으며(P<0.05), 그 변화 양상은 회장과 맹장에서 유사하게 나타났다. 단백질 및 지방 이용율이 유의하게 증가하였다(P<0.05), 건물 및 조회분에 있어서는 처리간 차이가 관찰되지 않았다. 시험 3에서는 유산균 적정 급여 빈도를 구명하기 위하여 1일령 육계 수평아리(Abor Acre) 600수를 공시하여 5처리 4반복, 반복당 30수씩 임의 배치하여 5주간 사양시험을 실시하였다. 시험처리는 항생제 무첨가구를 대조구로 하였으며, 유산균이 5.0×103cfu/mL 수준으로 첨가된 음수를 1일, 2일, 3일 및 5일 간격으로 급여한 유산균 처리구를 두었다. 5주 종료체중 및 증체량에 있어서 유산균을 매일 또는 격일로 급여시 유의하게 증가하였다(P<0.05). 사료섭취량 및 사료요구율은 처리구간 차이가 없었다. 회장과 맹장내 유산균의 수는 유산균 급여시 전체적으로 증가하는 경향을 보였으며, 특히 매일 및 격일 급여시 유의하게 증가하였다(P< 0.05). Coliform bacteria 및 Salmonella 수에 있어서는 처리구간 차이가 없었다. 본 시험 결과, 유산균의 음수 내 첨가 급여는 육계 생산성 및 장내 미생물 균총에 긍정적인 영향을 미쳤으며, 유산균의 적정 첨가 수준은 음수 1ml 당 유산균 5.0×103cfu이었으며, 급여 빈도에 있어서는 매일 급여하는 것이 효과적인 것으로 판단된다.

• BMB Reports
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• 제37권6호
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• pp.720-725
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• 2004

A number of signaling molecules contain small pleckstrin homology (PH) domains capable of binding phosphoinositides or proteins. Phospholipase C (PLC)-${\gamma}1$ has two putative PH domains, an $NH_2$-terminal (PH1) and a split PH domain ($nPH_2$ and $cPH_2$). We previously reported that the split PH domain of PLC-${\gamma}1$ binds to phosphatidylinositol 4-phosphate (PI(4)P) and phosphatidylinositol 4,5-bisphosphate (PI(4,5)$P_2$) (Chang et al., 2002). To identify the amino acid residues responsible for binding with PI(4)P and PI(4,5)$P_2$, we used site-directed mutagenesis to replace each amino acid in the variable loop-1 (VL-1) region of the PLC-${\gamma}1$ $nPH_2$ domain with alanine (a neutral amino acid). The phosphoinositide-binding affinity of these mutant molecules was analyzed by Dot-blot assay followed by ECL detection. We found that two PLC-${\gamma}1$ nPH2 domain mutants, P500A and H503A, showed reduced affinities for phosphoinositide binding. Furthermore, these mutant PLC-${\gamma}1$ molecules showed reduced PI(4,5)$P_2$ hydrolysis. Using green fluorescent protein (GFP) fusion protein system, we showed that both $PH_1$ and $nPH_2$ domains are responsible for membrane-targeted translocation of PLC-${\gamma}1$ upon serum stimulation. Together, our data reveal that the amino acid residues $Pro^{500}$ and $His^{503}$ are critical for binding of PLC-${\gamma}1$ to one of its substrates, PI(4,5)$P_2$ in the membrane.

• Experimental and Molecular Medicine
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• 제50권12호
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• pp.12.1-12.14
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• 2018

Osteoporosis develops with high prevalence in both postmenopausal women and hypogonadal men. Osteoporosis results in significant morbidity, but no cure has been established. Mesenchymal stem cells (MSCs) critically contribute to bone homeostasis and possess potent immunomodulatory/anti-inflammatory capability. Here, we investigated the therapeutic efficacy of using an infusion of MSCs to treat sex hormone-deficient bone loss and its underlying mechanisms. In particular, we compared the impacts of MSC cytotherapy in the two genders with the aim of examining potential gender differences. Using the gonadectomy (GNX) model, we confirmed that the osteoporotic phenotypes were substantially consistent between female and male mice. Importantly, systemic MSC transplantation (MSCT) not only rescued trabecular bone loss in GNX mice but also restored cortical bone mass and bone quality. Unexpectedly, no differences were detected between the genders. Furthermore, MSCT demonstrated an equal efficiency in rectifying the bone remodeling balance in both genders of GNX animals, as proven by the comparable recovery of bone formation and parallel normalization of bone resorption. Mechanistically, using green fluorescent protein (GFP)-based cell-tracing, we demonstrated rapid engraftment but poor inhabitation of donor MSCs in the GNX recipient bone marrow of each gender. Alternatively, MSCT uniformly reduced the $CD3^+T$-cell population and suppressed the serum levels of inflammatory cytokines in reversing female and male GNX osteoporosis, which was attributed to the ability of the MSC to induce T-cell apoptosis. Immunosuppression in the microenvironment eventually led to functional recovery of endogenous MSCs, which resulted in restored osteogenesis and normalized behavior to modulate osteoclastogenesis. Collectively, these data revealed recipient sexually monomorphic responses to MSC therapy in gonadal steroid deficiency-induced osteoporosis via immunosuppression/anti-inflammation and resident stem cell recovery.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제28권5호
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• pp.375-395
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• 2006

Purpose: Lingual nerve (LN) damage may be caused by either tumor resection or injury such as wisdom tooth extraction, Although autologous nerve graft is sometimes used to repair the damaged nerve, it has the disadvantage of necessity of another operation for nerve harvesting. Moreover, the results of nerve grafting is not satisfactory. The nerve growth factor (NGF) is well-known to play a critical role in peripheral nerve regeneration and its local delivery to the injured nerve has been continuously tried to enhance nerve regeneration. However, its application has limitations like repeated administration due to short half life of 30 minutes and an in vivo delivery model must allow for direct and local delivery. The aim of this study was to construct a well-functioning $rhNGF-{\beta}$ adenovirus for the ultimate development of improved method to promote peripheral nerve regeneration with enhanced and extended secretion of hNGF from the injured nerve by injecting $rhNGF-{\beta}$ gene directly into crush-injured LN in rat model. Materials and Methods: $hNGF-{\beta}$ gene was prepared from fetal brain cDNA library and cloned into E1/E3 deleted adenoviral vector which contains green fluorescence protein (GFP) gene as a reporter. After large scale production and purification of $rhNGF-{\beta}$ adenovirus, transfection efficiency and its expression at various cells (primary cultured Schwann cells, HEK293 cells, Schwann cell lines, NIH3T3 and CRH cells) were evaluated by fluorescent microscopy, RT-PCR, ELISA, immunocytochemistry. Furthermore, the function of rhNGF-beta, which was secreted from various cells infected with $rhNGF-{\beta}$ adenovirus, was evaluated using neuritogenesis of PC-12 cells. For in vivo evaluation of efficacy of $rhNGF-{\beta}$ adenovirus, the LNs of 8-week old rats were exposed and crush-injured with a small hemostat for 10 seconds. After the injury, $rhNGF-{\beta}$ adenovirus($2{\mu}l,\;1.5{\times}10^{11}pfu$) or saline was administered into the crushed site in the experimental (n=24) and the control group (n=24), respectively. Sham operation of another group of rats (n=9) was performed without administration of either saline or adenovirus. The taste recovery and the change of fungiform papilla were studied at 1, 2, 3 and 4 weeks. Each of the 6 animals was tested with different solutions (0.1M NaCl, 0.1M sucrose, 0.01M QHCl, or 0.01M HCl) by two-bottle test paradigm and the number of papilla was counted using SEM picture of tongue dorsum. LN was explored at the same interval as taste study and evaluated electro-physiologically (peak voltage and nerve conduction velocity) and histomorphometrically (axon count, myelin thickness). Results: The recombinant adenovirus vector carrying $rhNGF-{\beta}$ was constructed and confirmed by restriction endonuclease analysis and DNA sequence analysis. GFP expression was observed in 90% of $rhNGF-{\beta}$ adenovirus infected cells compared with uninfected cells. Total mRNA isolated from $rhNGF-{\beta}$ adenovirus infected cells showed strong RT-PCR band, however uninfected or LacZ recombinant adenovirus infected cells did not. NGF quantification by ELISA showed a maximal release of $18865.4{\pm}310.9pg/ml$ NGF at the 4th day and stably continued till 14 days by $rhNGF-{\beta}$ adenovirus infected Schwann cells. PC-12 cells exposed to media with $rhNGF-{\beta}$ adenovirus infected Schwann cell revealed at the same level of neurite-extension as the commercial NGF did. $rhNGF-{\beta}$ adenovirus injected experimental groups in comparison to the control group exhibited different taste preference ratio. Salty, sweet and sour taste preference ratio were significantly different after 2 weeks from the beginning of the experiment, which were similar to the sham group, but not to the control group.

• 생명과학회지
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• 제27권12호
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• pp.1445-1451
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• 2017

미토콘드리아는 산화적 인산화와 연결된 전자전달을 통하여 에너지 생산에 중추적인 역할을 갖는다. 이 외에도 미토콘드리아는 신진대사, 세포자멸, 신호전달 그리고 활성산소 생성 등의 다양한 기능을 수행한다. 따라서, 미토콘드리아의 기능장애는 여러 인체질환에 영향을 준다는 것이 명백하다. 또한, 미토콘드리아 DNA의 돌연변이는 에너지 신진대사에 결함이 있는 여러 유전성 질환의 원인을 제공한다. 불행하게도 아직 이러한 유전성 미토콘드리아 DNA 질환의 치료법은 전무한 상태이다. 이러한 관점에서, 결함 미토콘드리아를 정상 미토콘드리아로 치환하는 최근의 시도는 큰 주목을 받고 있다. 본 연구에서는 녹색형광단백질로 표지된 미토콘드리아를 원심분리에 기반하여 생화학적으로 분리하고, 분리된 미토콘드리아를 동물복제에 쓰이는 미세주입 기법으로 소 난자에 전달 하였다. 이러한 미토콘드리아가 미세주입된 난자에서 단위발생을 유도하여 배반포 단계까지의 초기 발생과정에서 미토콘드리아 미세주입의 영향을 분석하였다. 미토콘드리아에 표지된 녹색형광단백질을 형광현미경으로 분석함으로써 미세주입으로 난자에 전달된 미토콘드리아는 빠르게 세포질에서 분산되고, 이 후 발생되는 딸세포에게 전달됨이 확인되었다. 따라서, 본 연구에서 수행된, 미세주입을 이용한 미토콘드리아의 전달은 최근 활발히 연구되는 미토콘드리아 치환 기법, 유전성 미토콘드리아 DNA 질환 치료법 및 동물복제 등에 유용한 모델로의 기여가 기대된다.