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https://www.readbyqxmd.com/read/28532101/sonochemical-synthesis-of-fructose-1-6-bisphosphate-dicalcium-porous-microspheres-and-their-application-in-promotion-of-osteogenic-differentiation
#1
Chao Qi, Ding Zhou, Ying-Jie Zhu, Tuan-Wei Sun, Feng Chen, Chang-Qing Zhang
Human bone mesenchymal stem cells (hBMSCs) have the ability to differentiate into bone and cartilage for clinical bone regeneration. Biomaterials with an innate ability to stimulate osteogenic differentiation of hBMSCs into bone and cartilage are considered attractive candidates for the applications in bone tissue engineering and regeneration. In this paper, we synthesized fructose 1,6-bisphosphate dicalcium (Ca2FBP) porous microspheres by the sonochemical method, and investigated the ability of Ca2FBP for the promotion of the osteogenic differentiation of hBMSCs...
August 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28522548/a-multi-purpose-toolkit-to-enable-advanced-genome-engineering-in-plants
#2
Tomas Cermak, Shaun J Curtin, Javier Gil-Humanes, Radim Čegan, Thomas J Y Kono, Eva Konečná, Joseph J Belanto, Colby G Starker, Jade W Mathre, Rebecca L Greenstein, Daniel F Voytas
We report a comprehensive toolkit that enables targeted, specific modification of monocot and dicot genomes using a variety of genome engineering approaches. Our reagents, based on TALENs and the CRISPR/Cas9 system, are systematized for fast, modular cloning and accommodate diverse regulatory sequences to drive reagent expression. Vectors are optimized to create either single or multiple gene knockouts and large chromosomal deletions. Moreover, integration of geminivirus-based vectors enables precise gene editing through homologous recombination...
May 18, 2017: Plant Cell
https://www.readbyqxmd.com/read/28515784/improving-saccharomyces-cerevisiae-ethanol-production-and-tolerance-via-rna-polymerase-ii-subunit-rpb7
#3
Zilong Qiu, Rongrong Jiang
BACKGROUND: Classical strain engineering methods often have limitations in altering multigenetic cellular phenotypes. Here we try to improve Saccharomyces cerevisiae ethanol tolerance and productivity by reprogramming its transcription profile through rewiring its key transcription component RNA polymerase II (RNAP II), which plays a central role in synthesizing mRNAs. This is the first report on using directed evolution method to engineer RNAP II to alter S. cerevisiae strain phenotypes...
2017: Biotechnology for Biofuels
https://www.readbyqxmd.com/read/28515297/attenuation-of-foot-and-mouth-disease-virus-by-engineering-viral-polymerase-fidelity
#4
Devendra K Rai, Fayna Diaz-San Segundo, Grace Campagnola, Anna Keith, Elizabeth A Schafer, Anna Kloc, Teresa de Los Santos, Olve Peersen, Elizabeth Rieder
Foot-and-mouth disease virus (FMDV) RNA-dependent RNA polymerase (RdRp or 3D(pol)) catalyzes viral RNA synthesis. Its characteristic low fidelity and absence of proofreading activity allows FMDV to rapidly mutate and adapt to dynamic environments. In this study, we used the structure of FMDV 3D(pol) in combination with prior results from similar picornaviral polymerases to design point mutations that would alter replication fidelity. In particular, we targeted Trp237 within conserved polymerase motif A because of the low reversion potential inherent in the single UGG codon...
May 17, 2017: Journal of Virology
https://www.readbyqxmd.com/read/28512144/tog-tubulin-binding-specificity-promotes-microtubule-dynamics-and-mitotic-spindle-formation
#5
Amy E Byrnes, Kevin C Slep
XMAP215, CLASP, and Crescerin use arrayed tubulin-binding tumor overexpressed gene (TOG) domains to modulate microtubule dynamics. We hypothesized that TOGs have distinct architectures and tubulin-binding properties that underlie each family's ability to promote microtubule polymerization or pause. As a model, we investigated the pentameric TOG array of a Drosophila melanogaster XMAP215 member, Msps. We found that Msps TOGs have distinct architectures that bind either free or polymerized tubulin, and that a polarized array drives microtubule polymerization...
May 16, 2017: Journal of Cell Biology
https://www.readbyqxmd.com/read/28500952/isolation-and-characterization-of-lymphoid-enhancer-factor-1-positive-deciduous-dental-pulp-stem-like-cells-after-transfection-with-a-piggybac-vector-containing-lef1-promoter-driven-selection-markers
#6
Tomoya Murakami, Issei Saitoh, Masahiro Sato, Emi Inada, Miki Soda, Masataka Oda, Hisanori Domon, Yoko Iwase, Tadashi Sawami, Kazunari Matsueda, Yutaka Terao, Hayato Ohshima, Hirofumi Noguchi, Haruaki Hayasaki
OBJECTIVE: Lymphoid enhancer-binding factor-1 (LEF1) is a 48-kD nuclear protein that is expressed in pre-B and T cells. LEF1 is also an important member of the Wnt/β-catenin signaling pathway that plays important roles in the self-renewal and differentiation of embryonic stem cells. We speculated that LEF1 might function in the stem cells from human exfoliated deciduous teeth (SHED). In this study, we attempted to isolate such LEF1-positive cells from human deciduous dental pulp cells (HDDPCs) by genetic engineering technology, using the human LEF1 promoter...
May 7, 2017: Archives of Oral Biology
https://www.readbyqxmd.com/read/28467855/use-of-ice-nucleating-proteins-to-improve-the-performance-of-freeze-thaw-valves-in-microfluidic-devices
#7
Joseph C Gaiteri, W Hampton Henley, Nathan A Siegfried, Thomas H Linz, J Michael Ramsey
Currently, reliable valving on integrated microfluidic devices fabricated from rigid materials is confined to expensive and complex methods. Freeze-thaw valves (FTVs) can provide a low cost, low complexity valving mechanism, but reliable implementation of them has been greatly hindered by the lack of ice nucleation sites within the valve body's small volume. Work to date has required very low temperatures (on the order of -40 °C or colder) to induce freezing without nucleation sites, making FTVs impractical due to instrument engineering challenges...
May 11, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28464223/casting-eppcr-ceppcr-a-simple-random-mutagenesis-method-to-generate-high-quality-mutant-libraries
#8
Jianhua Yang, Anna J Ruff, Marcus Arlt, Ulrich Schwaneberg
During the last decade, directed evolution has become a standard protein engineering strategy to reengineer proteins for industrial applications under high stress conditions (e.g., high temperature, extreme pH, ionic liquids, or organic solvents). The most commonly employed method for diversity generation to improve biocatalysts for these properties is random mutagenesis by error-prone polymerase chain reaction (epPCR). However, recent reports show that epPCR often fails to produce >70% of beneficial positions/amino acid exchanges which improve enzyme properties such as organic solvent or ionic liquid resistance...
May 2, 2017: Biotechnology and Bioengineering
https://www.readbyqxmd.com/read/28463494/sort-seq-approach-to-engineering-a-formaldehyde-inducible-promoter-for-dynamically-regulated-escherichia-coli-growth-on-methanol
#9
Julia Rohlhill, Nicholas R Sandoval, Eleftherios T Papoutsakis
Tight and tunable control of gene expression is a highly desirable goal in synthetic biology for constructing predictable gene circuits and achieving preferred phenotypes. Elucidating the sequence-function relationship of promoters is crucial for manipulating gene expression at the transcriptional level, particularly for inducible systems dependent on transcriptional regulators. Sort-seq methods employing fluorescence-activated cell sorting (FACS) and high-throughput sequencing allow for the quantitative analysis of sequence-function relationships in a robust and rapid way...
May 9, 2017: ACS Synthetic Biology
https://www.readbyqxmd.com/read/28462820/short-dna-hairpins-compromise-recombinant-adeno-associated-virus-genome-homogeneity
#10
Jun Xie, Qin Mao, Phillip W L Tai, Ran He, Jianzhong Ai, Qin Su, Ye Zhu, Hong Ma, Jia Li, Shoufang Gong, Dan Wang, Zhen Gao, Mengxin Li, Li Zhong, Heather Zhou, Guangping Gao
Short hairpin (sh)RNAs delivered by recombinant adeno-associated viruses (rAAVs) are valuable tools to study gene function in vivo and a promising gene therapy platform. Our data show that incorporation of shRNA transgenes into rAAV constructs reduces vector yield and produces a population of truncated and defective genomes. We demonstrate that sequences with hairpins or hairpin-like structures drive the generation of truncated AAV genomes through a polymerase redirection mechanism during viral genome replication...
April 24, 2017: Molecular Therapy: the Journal of the American Society of Gene Therapy
https://www.readbyqxmd.com/read/28459860/nucleotide-time-alignment-for-molecular-recorders
#11
Thaddeus R Cybulski, Edward S Boyden, George M Church, Keith E J Tyo, Konrad P Kording
Using a DNA polymerase to record intracellular calcium levels has been proposed as a novel neural recording technique, promising massive-scale, single-cell resolution monitoring of large portions of the brain. This technique relies on local storage of neural activity in strands of DNA, followed by offline analysis of that DNA. In simple implementations of this scheme, the time when each nucleotide was written cannot be determined directly by post-hoc DNA sequencing; the timing data must be estimated instead...
May 2017: PLoS Computational Biology
https://www.readbyqxmd.com/read/28447733/gene-expression-profile-in-human-induced-pluripotent-stem-cells-chondrogenic-differentiation-in%C3%A2-vitro-part-b
#12
Ewelina Augustyniak, Wiktoria Maria Suchorska, Tomasz Trzeciak, Magdalena Richter
The development of human induced pluripotent stem cells (hiPSCs) is considered a turning point in tissue engineering. However, more data are required to improve understanding of key aspects of the cell differentiation process, including how specific chondrogenic processes affect the gene expression profile of chondrocyte‑like cells and the relative value of cell differentiation markers. The main aims of the present study were as follows: To determine the gene expression profile of chondrogenic‑like cells derived from hiPSCs cultured in mediums conditioned with HC‑402‑05a cells or supplemented with transforming growth factor β3 (TGF‑β3), and to assess the relative utility of the most commonly‑used chondrogenic markers as indicators of cell differentiation...
May 2017: Molecular Medicine Reports
https://www.readbyqxmd.com/read/28442664/induction-of-neural-crest-cells-from-human-dental-pulp-derived-induced-pluripotent-stem-cells
#13
Eisuke Kawano, Taku Toriumi, Shinya Iguchi, Daigo Suzuki, Shuichi Sato, Masaki Honda
We previously generated induced pluripotent stem (iPS) cells from human dental pulp cells of deciduous teeth. Neural crest cells (NCCs) play a vital role in the development of the oral and maxillofacial region. Therefore, NCCs represent a cell source for bone, cartilage, and tooth-related tissue engineering. In this study, we examined whether iPS cells are capable of differentiating into NCCs through modification of the human embryonic stem cell protocol. First, iPS cells were dissociated into single cells and then reaggregated in low-cell-adhesion plates with neural induction medium for 8 days in suspension culture to form neurospheres...
2017: Biomedical Research
https://www.readbyqxmd.com/read/28439535/a-murine-preclinical-syngeneic-transplantation-model-for-breast-cancer-precision-medicine
#14
Lorenzo Federico, Zechen Chong, Dong Zhang, Daniel J McGrail, Wei Zhao, Kang Jin Jeong, Christopher P Vellano, Zhenlin Ju, Mihai Gagea, Shuying Liu, Shreya Mitra, Jennifer B Dennison, Philip L Lorenzi, Robert Cardnell, Lixia Diao, Jing Wang, Yiling Lu, Lauren A Byers, Charles M Perou, Shiaw-Yih Lin, Gordon B Mills
We previously demonstrated that altered activity of lysophosphatidic acid in murine mammary glands promotes tumorigenesis. We have now established and characterized a heterogeneous collection of mouse-derived syngeneic transplants (MDSTs) as preclinical platforms for the assessment of personalized pharmacological therapies. Detailed molecular and phenotypic analyses revealed that MDSTs are the most heterogeneous group of genetically engineered mouse models (GEMMs) of breast cancer yet observed. Response of MDSTs to trametinib, a mitogen-activated protein kinase (MAPK) kinase inhibitor, correlated with RAS/MAPK signaling activity, as expected from studies in xenografts and clinical trials providing validation of the utility of the model...
April 2017: Science Advances
https://www.readbyqxmd.com/read/28420224/silk-fibroin-alginate-hydroxyapatite-composite-particles-in-bone-tissue-engineering-applications-in-vivo
#15
You-Young Jo, Seong-Gon Kim, Kwang-Jun Kwon, HaeYong Kweon, Weon-Sik Chae, Won-Geun Yang, Eun-Young Lee, Hyun Seok
The aim of this study was to evaluate the in vivo bone regeneration capability of alginate (AL), AL/hydroxyapatite (HA), and AL/HA/silk fibroin (SF) composites. Forty Sprague Dawley rats were used for the animal experiments. Central calvarial bone (diameter: 8.0 mm) defects were grafted with AL, AL/HA, or AL/HA/SF. New bone formation was evaluated by histomorphometric analysis. To demonstrate the immunocompatibility of each group, the level of tumor necrosis factor (TNF)-α expression was studied by immunohistochemistry (IHC) and quantitative reverse transcription polymerase chain reaction (qRT-PCR) at eight weeks post implantation...
April 18, 2017: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/28419944/electrochemical-synthesis-of-three-dimensional-porous-reduced-graphene-oxide-film-preparation-and-in-vitro-osteogenic-activity-evaluation
#16
Zizhu Tian, Lixun Huang, Xibo Pei, Junyu Chen, Tong Wang, Tao Yang, Han Qin, Lei Sui, Jian Wang
In this study, three-dimensional reduced graphene oxide (3D-rGO) porous films were fabricated using a two-step electrochemical method, including an electrochemical deposition process for the self-assembly of GO and an electrochemical bubbling-based transfer. The morphology, physical properties, and phase composition of the 3D-rGO films were characterized, and the cellular bioactivities were evaluated using pre-osteoblasts (MC3T3-E1 cells). The attachment, proliferation and differentiation of the MC3T3-E1 cells on the 3D-rGO films was analyzed by scanning electron microscopy (SEM), Cell Counting Kit-8 (CCK-8) assays and live/dead cell staining, and alkaline phosphatase (ALP) activity assays, respectively...
April 12, 2017: Colloids and Surfaces. B, Biointerfaces
https://www.readbyqxmd.com/read/28409292/effects-of-the-donor-age-on-proliferation-senescence-and-osteogenic-capacity-of-human-urine-derived-stem-cells
#17
Peng Gao, Peilin Han, Dapeng Jiang, Shulong Yang, Qingbo Cui, Zhaozhu Li
To study the effects of the donor age on the application potential of human urine-derived stem cells (hUSCs) in bone tissue engineering, by comparing proliferation, senescence and osteogenic differentiation of hUSCs originated from volunteers with different ages. The urine samples were collected from 19 healthy volunteers (6 cases from children group aged from 5 to 14, 5 cases from middle-aged group aged from 30 to 40, and 8 cases from the elder group aged from 65 to 75), and hUSCs were isolated and cultured...
April 13, 2017: Cytotechnology
https://www.readbyqxmd.com/read/28383245/exploring-the-chemistry-of-genetic-information-storage-and-propagation-through-polymerase-engineering
#18
Gillian Houlihan, Sebastian Arangundy-Franklin, Philipp Holliger
Nucleic acids are a distinct form of sequence-defined biopolymer. What sets them apart from other biopolymers such as polypeptides or polysaccharides is their unique capacity to encode, store, and propagate genetic information (molecular heredity). In nature, just two closely related nucleic acids, DNA and RNA, function as repositories and carriers of genetic information. They therefore are the molecular embodiment of biological information. This naturally leads to questions regarding the degree of variation from this seemingly ideal "Goldilocks" chemistry that would still be compatible with the fundamental property of molecular heredity...
April 18, 2017: Accounts of Chemical Research
https://www.readbyqxmd.com/read/28381166/downregulation-of-microrna-181d-had-suppressive-effect-on-pancreatic-cancer-development-through-inverse-regulation-of-knain2
#19
Guopeng Zhang, Dongbo Liu, Guoxian Long, Lei Shi, Hong Qiu, Guangyuan Hu, Guoqing Hu, Shunfang Liu
We explored the expression and function of miR-181d (microRNA-181d) in human pancreatic cancer. Quantitative real-time polymerase chain reaction was used to probe miR-181d expression in both pancreatic cancer cell lines and human pancreatic carcinoma. Pancreatic cancer cell lines, PANC-1 and AsPC-1 cells, were engineered to stably downregulate endogenous miR-181d through lentiviral transduction. The mechanistic effects of miR-181d downregulation on pancreatic cancer development were tested by proliferation, migration, fluorouracil chemosensitivity assays in vitro, and explant assay in vivo...
April 2017: Tumour Biology: the Journal of the International Society for Oncodevelopmental Biology and Medicine
https://www.readbyqxmd.com/read/28369677/direct-isolation-of-seamless-mutant-bacterial-artificial-chromosomes
#20
George T Lyozin, Yasuhiro Kosaka, Gourab Bhattacharje, H Joseph Yost, Luca Brunelli
Seamless (i.e., without unwanted DNA sequences) mutant bacterial artificial chromosomes (BACs) generated via recombination-mediated genetic engineering (recombineering) are better suited to study gene function compared to complementary DNA (cDNA) because they contain only the specific mutation and provide all the regulatory sequences required for in vivo gene expression. However, precisely mutated BACs are typically rare (∼1:1,000 to 1:100,000), making their isolation quite challenging. Although these BACs have been classically isolated by linking the mutation to additional genes, i...
April 3, 2017: Current Protocols in Molecular Biology
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