In Vitro Systems for Coupling RNAP II Transcription to Splicing and Polyadenylation

High resolution X-ray crystal structures of multisubunit RNA polymerases (RNAP) have contributed to our understanding of transcriptional mechanisms. They also provided a powerful guide for the design of experiments aimed at further characterizing the molecular stages of the transcription reaction. Our laboratory used tandem-affinity peptide purification in native conditions to isolate human RNAP II variants that had site-specific mutations in structural elements located strategically within the enzyme's catalytic center. Both in vitro and in vivo analyses of these mutants revealed novel features of the catalytic mechanisms involving this enzyme.Key words: RNA polymerase II, transcriptional mechanisms, mutational analysis, mRNA synthesis.

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Academic collaborative models fostering the translation of physiological in vitro systems from basic research into drug discovery

Drug Discovery Today ◽

10.1016/j.drudis.2021.02.024 ◽

2021 ◽

Author(s):

Alessandra Silvestri ◽

Francisca Vicente ◽

María J. Vicent ◽

Bahne Stechmann ◽

Wolfgang Fecke

Keyword(s):

Drug Discovery ◽

Basic Research ◽

Collaborative Models ◽

In Vitro Systems

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Human Oligodendrocytes and Myelin In Vitro to Evaluate Developmental Neurotoxicity

International Journal of Molecular Sciences ◽

10.3390/ijms22157929 ◽

2021 ◽

Vol 22 (15) ◽

pp. 7929

Author(s):

Megan Chesnut ◽

Thomas Hartung ◽

Helena Hogberg ◽

David Pamies

Keyword(s):

Large Scale ◽

In Vitro Models ◽

Environmental Chemicals ◽

Developmental Neurotoxicity ◽

In Vivo Studies ◽

Regulatory Guidelines ◽

In Vitro Systems ◽

Human Oligodendrocytes

Neurodevelopment is uniquely sensitive to toxic insults and there are concerns that environmental chemicals are contributing to widespread subclinical developmental neurotoxicity (DNT). Increased DNT evaluation is needed due to the lack of such information for most chemicals in common use, but in vivo studies recommended in regulatory guidelines are not practical for the large-scale screening of potential DNT chemicals. It is widely acknowledged that developmental neurotoxicity is a consequence of disruptions to basic processes in neurodevelopment and that testing strategies using human cell-based in vitro systems that mimic these processes could aid in prioritizing chemicals with DNT potential. Myelination is a fundamental process in neurodevelopment that should be included in a DNT testing strategy, but there are very few in vitro models of myelination. Thus, there is a need to establish an in vitro myelination assay for DNT. Here, we summarize the routes of myelin toxicity and the known models to study this particular endpoint.

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Protein-templated gold nanoclusters as specific bio-imaging probes for the detection of Hg(ii) ions in in vivo and in vitro systems: discriminating between MDA-MB-231 and MCF10A cells

The Analyst ◽

10.1039/d0an02108c ◽

2021 ◽

Author(s):

Subhajit Chakraborty ◽

Atanu Nandy ◽

Subhadip Ghosh ◽

Nirmal Kumar Das ◽

Sameena Parveen ◽

...

Keyword(s):

Breast Cancer ◽

Human Serum Albumin ◽

Gold Nanoclusters ◽

Selective Detection ◽

Imaging Probes ◽

Bio Imaging ◽

In Vitro Systems ◽

Mcf10a Cells

Sub-nanomolar selective detection of Hg(ii) ions by protein (Human Serum Albumin, HSA) templated gold nanoclusters (AuNCs), both in in vitro as well as in vivo environments and specific endocytose behaviour towards breast cancer (BC) cell lines.

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The Use of In Vitro Systems for Evaluating Haematotoxicity

Alternatives to Laboratory Animals ◽

10.1177/026119299602400212 ◽

1996 ◽

Vol 24 (2) ◽

pp. 211-231

Author(s):

Laura Gribaldo ◽

Juan Bueren ◽

Ahmed Deldar ◽

Peter Hokland ◽

Clive Meredith ◽

...

Keyword(s):

In Vitro Systems

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STUDIES ON THE ANTITHROMBOTIC ACTION OF A LOW MOLECULARWEIGHT HEPARIN OBTAINED FROM BEEF MUCOSAL ORIGIN AND PEROXIDATIVE CLEAVAGE

10.1055/s-0038-1644164 ◽

1987 ◽

Author(s):

P Bianchini ◽

R Nonn ◽

J Fareed ◽

J M Walenga ◽

A Kumar

Keyword(s):

Molecular Weight ◽

Structural Integrity ◽

Factor Xa ◽

Inhibitory Effects ◽

Heparin Cofactor Ii ◽

At Iii ◽

Antithrombotic Effects ◽

In Vitro Systems ◽

Mean Molecular Weight

We have studied a low molecular weight heparin (LMWH) obtained by acontrolled peroxidative depolymerization of beef mucosal heparin (OP 2123, Opocrin, Corlo, Italy). This product was found to be significantly different from other LMWHs in that it exhibits the same COO-/SO2- ratios as unfractionated heparin, contains reducing end groups composed of 2-sulfated iduronic acid or 6-disulfated glucosamine and retains an identical structural integrity as that of native heparin. As opposed to most other LMWHs the oligosaccharide components of OP 2123 consist of homogeneous progressive units. In addition, the relative amount of AT-IIIaffinity components in OP 2123 were 20-30% less than other LMWHs. OP 2123 has a mean molecular weight of 6200 daltons with a potency of 90 anti-factor Xa U/mg and 68 USP U/mg. This agent produced strong antithrombotic actions in a rabbit stasis model against both an activated prothrombin complex and a prothrombin complex concentrate/Russell's viper venomcombination (ED50:(IV) 30-70 ug/kg;(SC) 0.6-1.5 mg/kg). The antithrombotic effects were comparable to other LMWHs in normal rabbits: however, in AT III depleted rabbits (immunodepleted and y thrombin depleted), OP 2123 produced stronger antithrombotic effects than most other LMWHs. The in vitro systems in contrast to other LMWHs, CP 2123 produced stronger inhibitory effects in AT III depleted plasma as measured by fibrinopeptide A generation and amidolytic anti-factor Xa and anti-factor Ila methods. The relative heparin cofactor II activity as measured by amidolytic method was also found to be higher than with most LMWHs. These results suggest that OP 2123, unlike most LMWHs, non AT III mediated actions play a major role in themendiation of the antithrombotic actions.

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