| 1. |
- Yoo, Lina, et al.
(författare)
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A simple one-step assay platform based on fluorescence quenching of macroporous silicon
- 2013
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Ingår i: Biosensors & Bioelectronics. - : Elsevier BV. - 1873-4235 .- 0956-5663. ; 41, s. 477-483
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Tidskriftsartikel (refereegranskat)abstract
- We synthesized 3D macroporous silicon through a simple electrochemical dissolution process and systematically estimated its protein adsorption and effect on fluorescence emission. Compared with conventional 2D polystyrene plate, the macroporous silicon showed a superior protein adsorption capacity and significant fluorescence quenching effect. We developed a 3D macroporous silicon-based adenosine assay system through the following fabrication process: streptavidin molecules that have been immobilized on the surface of macroporous silicon are attached with biotin-linked and adenosine-specific DNA aptamer, followed by hybridization between the attached aptamer and fluorescent chemical (carboxytetramethylrhodamine/CTMR) that is conjugated with a short complementary DNA sequence. In the absence of adenosine, the aptamer-CTMR complexes remain closely attached to the surface of porous silicon, hence fluorescence being significantly quenched. Upon binding to adenosine, the DNA aptamer is subject to structure switching that leads to dissociation of CTMR from DNA aptamer, and consequently the CTMR fluorescence is restored, indicating a simple one-step assay of adenosine. Compared to the conventional 2D PS and ZnO nanorods-based assays, adenosine at much lower (sub-micromolar) concentration was successfully detected through the 3D macroporous silicon-based assay. The three-dimensionally and densely immobilized aptamer probes and effective fluorescence quenching on the surface of macroporous silicon enables adenosine to be detected at lower levels. Although the adenosine detection is reported here as a proof-of-concept, the developed macroporous silicon-based simple one-step assay platform can be applied in general to fluorescence quenching -based detection of many other biomolecules. (C) 2012 Elsevier B.V. All rights reserved.
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| 2. |
- Cho, Hyunsoo, et al.
(författare)
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YAP and TAZ Negatively Regulate Prox1 During Developmental and Pathologic Lymphangiogenesis
- 2019
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Ingår i: Circulation Research. - : Lippincott Williams & Wilkins. - 0009-7330 .- 1524-4571. ; 124:2, s. 225-242
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Tidskriftsartikel (refereegranskat)abstract
- Rationale: The Hippo pathway governs cellular differentiation, morphogenesis, and homeostasis, but how it regulates these processes in lymphatic vessels is unknown. Objective: We aimed to reveal the role of the final effectors of the Hippo pathway, YAP (Yes-associated protein) and TAZ (transcriptional coactivator with PDZ-binding motif), in lymphatic endothelial cell (LEC) differentiation, morphogenesis, and homeostasis. Methods and Results: During mouse embryonic development, LEC-specific depletion of Yap/Taz disturbed both plexus patterning and valve initiation with upregulated Prox1 (prospero homeobox 1). Conversely, LEC-specific YAP/TAZ hyperactivation impaired lymphatic specification and restricted lymphatic sprouting with profoundly downregulated Prox1. Notably, lymphatic YAP/TAZ depletion or hyperactivation aggravated or attenuated pathological lymphangiogenesis in mouse cornea. Mechanistically, VEGF (vascular endothelial growth factor)-C activated canonical Hippo signaling pathway in LECs. Indeed, repression of PROX1 transcription by YAP/TAZ hyperactivation was mediated by recruitment of NuRD (nucleosome remodeling and histone deacetylase) complex and endogenous binding activity of TEAD (TEA domain family members) to the PROX1 promoter. Furthermore, YAP/TAZ hyperactivation enhanced MYC signaling and inhibited CDKN1C, leading to cell cycle dysregulation and aberrant proliferation. Conclusions: We find that YAP and TAZ play promoting roles in remodeling lymphatic plexus patterning and postnatal lymphatic valve maintenance by negatively regulating Prox1 expression. We further show that YAP and TAZ act as plastic regulators of lymphatic identity and define the Hippo signaling-mediated PROX1 transcriptional programing as a novel dynamic checkpoint underlying LEC plasticity and pathophysiology.
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| 3. |
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| 4. |
- Ahn, Ji-Young, et al.
(författare)
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Sol-Gel Derived Nanoporous Compositions for Entrapping Small Molecules and Their Outlook toward Aptamer Screening
- 2012
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Ingår i: Analytical Chemistry. - : American Chemical Society (ACS). - 1520-6882 .- 0003-2700. ; 84:6, s. 2647-2653
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Tidskriftsartikel (refereegranskat)abstract
- This paper reports for the first time the application of sol-gel microarrays for immobilizing nonsoluble small chemicals (Bisphenol-A; BPA). Also, known problems of sol-gel adhesion to conventional microtiter well plate substrates are circumvented by anchoring the sol-gel microspots to a porous silion surface so-called, PS-SG chips. We confirmed low molecular weight chemical immobilization inside a sol-gel network using fluorescein. BPA and the BPA specific aptamer were utilized as a model pair to verify the affinity specific interaction in the PS-SG selection system. The aptamer interacted specifically with BPA in the sol-gel spots, as shown in microarrays forming the letters "L", "U", "N", and "D". Moreover, the bound aptamer was released by heat, recovered, and verified by gel electrophoresis. The developed PS-SG chip platform will be used for screening aptamers against numerous small molecules such as toxins, metabolites, or pesticide residues.
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| 5. |
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| 6. |
- Ji-Young, Ahn, et al.
(författare)
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Aptamer microarray mediated capture and mass spectrometry identification of biomarker in serum samples.
- 2010
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Ingår i: Journal of Proteome Research. - : American Chemical Society (ACS). - 1535-3893 .- 1535-3907. ; 9:11, s. 5568-5573
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Tidskriftsartikel (refereegranskat)abstract
- Sensitive detection of molecular biomarkers in clinical samples is crucially important in disease diagnostics. This paper reports the developement of an aptamer microarray platform combined with sol-gel technology to identify low-abundance targets in complex serum samples. Because of the nanoporous structure of the sol-gel, a high capacity to immobilize the affinity specific aptamers is accomplished which allows binding and detection of target molecules with high sensitivity. The captured protein is digested in situ and the obtained digest was analyzed by ESI-MS without any interference from the affinity probe. TBP (TATA Box Protein) and its specific aptamers were chosen as a model system. A proof of concept with protein concentrations ranging between nanomolar to micromolar is reported, showing a good linearity up to 400 nM when characterized in an aptamer sandwich assay. Moreover, as low as 0.001% of target protein present in total serum proteins could be identified without any pretreatment step using ESI MS/MS mass spectrometry. We believe this novel strategy could become an efficient method for aptamer-based biomarker detection linked directly to mass spectrometry readout.
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| 7. |
- Kim, Tae Kyung, et al.
(författare)
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Fabrication of Microfluidic Platform with Optimized Fluidic Network toward On-Chip Parallel Systematic Evolution of Ligands by Exponential Enrichment Process
- 2011
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Ingår i: Japanese Journal of Applied Physics. - 0021-4922. ; 50:6, s. 05-06
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents the design and fabrication of a microplatform with the optimal fluidic network for an on-chip parallel "systematic evolution of ligands by exponential enrichment" (SELEX) process. The effectiveness of the optimized fluidic network for on-chip five-plex aptamer screening was verified by measuring the airflow rate at the elution ports and visualizing the specific elution during the SELEX process. The proposed device with an optimally designed hydraulic resistance-balanced channel network could be feasible and utilized as a multiplex selection module for a parallel SELEX process. (c) 2011 The Japan Society of Applied Physics
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| 8. |
- Park, Kwang-Hyun, et al.
(författare)
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RNA activation-independent DNA targeting of the Type III CRISPR-Cas system by a Csm complex
- 2017
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Ingår i: EMBO Reports. - : Wiley-VCH Verlagsgesellschaft. - 1469-221X .- 1469-3178. ; 18:5, s. 826-840
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Tidskriftsartikel (refereegranskat)abstract
- The CRISPR-Cas system is an adaptive and heritable immune response that destroys invading foreign nucleic acids. The effector complex of the Type III CRISPR-Cas system targets RNA and DNA in a transcription-coupled manner, but the exact mechanism of DNA targeting by this complex remains elusive. In this study, an effector Csm holocomplex derived from Thermococcus onnurineus is reconstituted with a minimalistic combination of Csm1(1)2(1)3(3)4(1)5(1), and shows RNA targeting and RNA-activated single-stranded DNA (ssDNA) targeting activities. Unexpectedly, in the absence of an RNA transcript, it cleaves ssDNA containing a sequence complementary to the bound crRNA guide region in a manner dependent on the HD domain of the Csm1 subunit. This nuclease activity is blocked by a repeat tag found in the host CRISPR loci. The specific cleavage of ssDNA without a target RNA suggests a novel ssDNA targeting mechanism of the Type III system, which could facilitate the efficient and complete degradation of foreign nucleic acids.
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| 9. |
- Zhou, Jinyuan, et al.
(författare)
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Review and consensus recommendations on clinical APT-weighted imaging approaches at 3T : Application to brain tumors
- 2022
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Ingår i: Magnetic Resonance in Medicine. - : Wiley. - 1522-2594 .- 0740-3194. ; 88:2, s. 546-574
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Tidskriftsartikel (refereegranskat)abstract
- Amide proton transfer-weighted (APTw) MR imaging shows promise as a biomarker of brain tumor status. Currently used APTw MRI pulse sequences and protocols vary substantially among different institutes, and there are no agreed-on standards in the imaging community. Therefore, the results acquired from different research centers are difficult to compare, which hampers uniform clinical application and interpretation. This paper reviews current clinical APTw imaging approaches and provides a rationale for optimized APTw brain tumor imaging at 3 T, including specific recommendations for pulse sequences, acquisition protocols, and data processing methods. We expect that these consensus recommendations will become the first broadly accepted guidelines for APTw imaging of brain tumors on 3 T MRI systems from different vendors. This will allow more medical centers to use the same or comparable APTw MRI techniques for the detection, characterization, and monitoring of brain tumors, enabling multi-center trials in larger patient cohorts and, ultimately, routine clinical use.
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