scholarly journals ChIP-on-chip analysis of thyroid hormone-regulated genes and their physiological significance

Oncotarget ◽  
2016 ◽  
Vol 7 (16) ◽  
pp. 22448-22459 ◽  
Author(s):  
I-Hsiao Chung ◽  
Hsuan Liu ◽  
Yang-Hsiang Lin ◽  
Hsiang-Cheng Chi ◽  
Ya-Hui Huang ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Physiological Significance ◽  
On Chip ◽  
Chip Analysis

scholarly journals Integrating Biosensors in Organs-on-Chip Devices: A Perspective on Current Strategies to Monitor Microphysiological Systems

Biosensors ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 110 ◽  
Author(s):  
Erika Ferrari ◽  
Cecilia Palma ◽  
Simone Vesentini ◽  
Paola Occhetta ◽  
Marco Rasponi
Keyword(s):  
Imaging Techniques ◽  
Biological Models ◽  
Electromechanical Properties ◽  
Human Organs ◽  
Tissue Constructs ◽  
Microphysiological Systems ◽  
Metabolic Activities ◽  
On Chip ◽  
Chip Analysis

Organs-on-chip (OoC), often referred to as microphysiological systems (MPS), are advanced in vitro tools able to replicate essential functions of human organs. Owing to their unprecedented ability to recapitulate key features of the native cellular environments, they represent promising tools for tissue engineering and drug screening applications. The achievement of proper functionalities within OoC is crucial; to this purpose, several parameters (e.g., chemical, physical) need to be assessed. Currently, most approaches rely on off-chip analysis and imaging techniques. However, the urgent demand for continuous, noninvasive, and real-time monitoring of tissue constructs requires the direct integration of biosensors. In this review, we focus on recent strategies to miniaturize and embed biosensing systems into organs-on-chip platforms. Biosensors for monitoring biological models with metabolic activities, models with tissue barrier functions, as well as models with electromechanical properties will be described and critically evaluated. In addition, multisensor integration within multiorgan platforms will be further reviewed and discussed.

A Microfluidic Platform for On-Chip Analysis of Circulating Tumor Cells

2021 ◽  
Author(s):  
Jeff Darabi ◽  
Joseph Schober
Keyword(s):  
Cancer Cells ◽  
Tumor Cells ◽  
Circulating Tumor Cells ◽  
Whole Blood ◽  
Peripheral Blood ◽  
Automated Image Analysis ◽  
Rare Cancer ◽  
On Chip ◽  
Chip Analysis ◽  
Selection Of

Abstract Studies have shown that primary tumor sites begin shedding cancerous cells into peripheral blood at early stages of cancer, and the presence and frequency of circulating tumor cells (CTCs) in blood is directly proportional to disease progression. The challenge is that the concentration of the CTCs in peripheral blood may be extremely low. In the past few years, several microfluidic-based concepts have been investigated to isolate CTCs from whole blood. However, these devices are generally hampered by complex fabrication processes and very low volumetric throughputs, which may not be practical for rapid clinical applications. This paper presents a high-performance yet simple magnetophoretic microfluidic chip for the enrichment and on-chip analysis of rare CTCs from blood. Microscopic and flow cytometric assays developed for selection of cancer cell lines, selection of monoclonal antibodies, and optimization of bead coupling are discussed. Additionally, on-chip characterization of rare cancer cells using high resolution immunofluorescence microscopy and modeling results for prediction of CTC capture length are presented. The device has the ability to interface directly with on-chip pre and post processing modules such as mixing, incubation, and automated image analysis systems. These features will enable us to isolate rare cancer cells from whole blood and detect them on the chip with subcellular resolution.

Chromosome conformation capture-on-chip analysis of long-range cis-interactions of the SOX9 promoter

2013 ◽  
Vol 21 (8) ◽  
pp. 781-788 ◽  
Author(s):  
Marta Smyk ◽  
Przemyslaw Szafranski ◽  
Michał Startek ◽  
Anna Gambin ◽  
Paweł Stankiewicz
Keyword(s):  
Long Range ◽  
Chromosome Conformation Capture ◽  
Chromosome Conformation ◽  
On Chip ◽  
Chip Analysis

Advanced 3D Packaging of Chips and Materials Integrity: Stress-Induced Effects and Mechanical Properties of New Ultra Low-k Dielectrics for On-Chip Interconnect Stacks

2013 ◽  
Vol 592-593 ◽  
pp. 563-568
Author(s):  
Christoph Sander ◽  
Martin Gall ◽  
Kong Boon Yeap ◽  
Ehrenfried Zschech
Keyword(s):  
Computing Time ◽  
Orientation Dependence ◽  
Chip Design ◽  
Simulation Methodology ◽  
3D Packaging ◽  
Internal Mechanical Stress ◽  
On Chip ◽  
Physics Based Simulation ◽  
Low K ◽  
Chip Analysis

Managing the emerging internal mechanical stress in chips particularly if they are 3D-tscked is a key task to maintain performance and reliability of microelectronic products. Hence, a strong need of a physics-based simulation methodology/flow emerges. This physics-based simulation, however, requires materials parameters with high accuracy. A full-chip analysis can then be performed, balancing the need for local resolution and computing time. Therefore, effective composite-type materials data for several regions of interest are needed. Advanced techniques to measure FEA-and design-relevant properties such as local and effective Youngs modulus and effective CTE values were developed and described in this paper. These data show a clear orientation dependence, caused by the chip design.

Effects of intrathyroidal metabolism of thyroxine on thyroid hormone secretion: increased degradation of thyroxine in mouse thyroids stimulated chronically with thyrotrophin

1984 ◽  
Vol 105 (1) ◽  
pp. 57-65 ◽  
Author(s):  
Ken Kubota ◽  
Hidemasa Uchimura ◽  
Tomoaki Mitsuhashi ◽  
Shoo Cheng Chiu ◽  
Nobuaki Kuzuya ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Hormone Secretion ◽  
Plasma Concentrations ◽  
Experimental Period ◽  
Physiological Significance ◽  
The Media ◽  
Bovine Tsh ◽  
Tsh Levels ◽  
Mouse Thyroid

Abstract. Mice were infused continuously with graded doses of bovine TSH (bTSH) and changes in plasma concentrations of bTSH and T4 were measured. Then mice infused with 100 mU TSH per day were sacrificed on days 0, 1, 3 and 5 and their thyroids were excised to determine in vitro secretion of T4, T3 and rT3 during 3 h of incubation. At the end of the incubation, thyroidal contents of T4, T3 and rT3 were also determined after pronase digestion. Plasma bTSH levels were increased on day 1 to a level of 110 μU/ml and remained unchanged thereafter. Plasma T4 concentrations increased approximately 2-fold on day 1, but decreased to initial levels on days 3 and 5. Changes in T4 secretion in vitro paralleled those in plasma T4 concentrations; T4 secretion increased 2-fold on day 1, and decreased to the pre-TSH levels on days 3 and 5. In contrast, T3 secretion increased throughout the experimental period. The T3/T4 ratio in thyroidal secretion in vitro was the same as that in thyroidal contents on days 0 and 1 of TSH infusion, but the former was significantly greater than the latter on days 3 and 5. PTU (5.9 × 10−5 m), a known inhibitor of T4 deiodination, added to the incubation media did not affect T4 secretion on days 0 and 1, but increased T4 secretion on days 3 and 5 to the level of day 1, but did not affect T3 secretion. In the presence of PTU, the T3/T4 ratio in thyroidal secretion did not differ from that in thyroidal contents throughout the experimental period. Secretion of rT3 was increased on days 3 and 5 and PTU augmented this increase. Thyroidal content of rT3 was much increased on days 3 and 5. In contrast, methimazole (10−3 m), which does not inhibit in vitro T4 deiodination, added to the incubation media did not affect T4, T3 and rT3 secretion in vitro. When [125I]T4 was added to the media and incubated with mouse thyroid, no labelled products of T4-deiodination were observed to appear in the media even in mice infused with TSH for 5 days. These results suggest that intrathyroidal metabolism of T4 has physiological significance in controlling thyroid hormone secretion at least in TSH-stimulated thyroids.

ChIP-on-Chip Analysis Using Dominant Negative Form of PAX5 Fusion Gene Revealed Genes Associated with Tumorigenesis Were Directly Regulated by PAX5 in a Human B Cell Line, NALM6

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3585-3585
Author(s):  
Norihiko Kawamata ◽  
Fabienne Isken ◽  
Stefanie Goellner ◽  
C. Müller-Tidow ◽  
H. Phillip Koeffler
Keyword(s):  
B Cell ◽  
Specific Antibody ◽  
Target Genes ◽  
Chimeric Protein ◽  
Dominant Negative ◽  
Wild Type ◽  
Dominant Negative Form ◽  
On Chip ◽  
Chip Analysis ◽  
Negative Form

Abstract PAX5 is a transcriptional factor playing an important role in B-cell development. Overexpression of PAX5 induced by translocation to the enhancer region of immunoglobulin heavy chain gene occurs in non-Hodgkin lymphomas (NHL), suggesting that PAX5 can be also associated with development of NHL. To identify genes associated with tumorigenesis in malignancies overexpressing PAX5, we performed ChIP-on-chip analysis using PAX5 specific antibody. Non-specifically immunoprecipitated DNA by antibodies can cause false positive results using ChIP-on-chip analysis (background). To reduce the background in ChIP-on chip analysis, we used a dominant negative form of PAX5 and a wild-type PAX5 specific antibody for our ChIP-on-chip analysis. We have previously found a PAX5 chimeric protein expressed in acute lymphoblastic leukemia in which the C-terminal end of PAX5 was replaced by C20ORF112 protein (Kawamata N et al, Proc Natl Acad Sci U S A. Aug. 12, 2008). We have also found that this chimeric protein behaved in a dominant negative fashion over the wild-type PAX5 and suppressed expression of target genes of wild-type PAX5. PAX5 chimeric protein can compete with wild-type PAX5 for binding on the promoter region of direct down-stream target genes. To identify the genes directly regulated by PAX5 in human B-cells, we transfected the dominant-negative form of PAX5 chmeric protein, PAX5-C20ORF112 (PAX5-C20S) into NALM6 human B-cell leukemia cells which constitutively express abundant PAX5. Transfected cells were collected and chromatin immunoprecipitation (ChIP) assay was performed using PAX5 C-terminal specific antibody which can recognize only wild-type PAX5, but not the chimeric PAX5 protein, PAX5C20S. As a control, we also performed ChIP assay using NALM6 cells transfected with an empty vector. Immunoprecipitated DNA was recovered and amplified using the whole genome amplification technique. The DNAs were hybridized with oligonucleotide probes containing the promoter regions of the human genome. The levels of hybridized DNA were quantified and genes directly bound by PAX5 were identified. Comparison between NALM6 cells transfected with the empty vector and PAX5C20S significantly reduced the background and allowed identification of genes directly regulated by PAX5 in NALM6, including BUB1B, SSSCA1, CEP68, and BAG1. BUB1B, CEP68 and SSSCA1 are proteins involved in mitosis; BAG1 is a protein associated with apoptosis. Dysregulation of these genes by overexpressed PAX5 may be associated with development of B-cell malignancies.

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