high-throughput-dna-plasmid-multiplexing-transfection-using-acoustic

High-Throughput DNA Plasmid Multiplexing and Transfection Using Acoustic Nanodispensing Technology

Cell transfection, indispensable for many biological studies, requires controlling many parameters for an accurate and successful achievement. Most often ...

Université de Lille

The goal of this paper is to review the variety of approaches adopted to improve lead generation, and make the process easier for the chemist, faster and more likely to succeed in later phases of drug development. Our analysis shows that successful lead generation requires not only an accurate definition of the needs (to define the most relevant assay protocols and readouts), but most of all a good hit as a starting point. It also appears that teams where techniques are combined are more successful in that difficult game.

Facts, figures and trends in lead generation.

One approach currently being developed in anticancer drug discovery is to search for small compounds capable of occupying and blocking the hydrophobic pocket of anti-apoptotic Bcl-2 family members necessary for interacting with pro-apoptotic proteins. Such an approach led to the discovery of several compounds, such as ABT-737 (which interacts with Bcl-2, Bcl-xl, and Bcl-w) or the latest one, ABT-199, that selectively targets Bcl-2 protein. The efficacy of those compounds is, however, limited by the expression of two other anti-apoptotic Bcl-2 members, Mcl-1 and Bfl-1. Based on the role of Bfl-1 in cancer, especially in chemoresistance associated with its overexpression in B-cell malignancies, we searched for modulators of protein-protein interaction through a high-throughput screening of a designed chemical library with relaxed drug-like properties to identify small molecules targeting Bfl-1 anti-apoptotic protein. We found two compounds that display electrophilic functions, interact with Bfl-1, inhibit Bfl-1 protective activity, and promote cell death of malignant B cells. Of particular interest, we observed a synergistic effect of those compounds with ABT-737 in Bfl-1 overexpressing lymphoma cell lines. Our results provide the basis for the development of Bfl-1 specific antagonists for antitumor therapies. 

Identification of Small Inhibitory Molecules Targeting the Bfl-1 Anti-Apoptotic Protein That Alleviates Resistance to ABT-737.

Rapid and efficient structural analysis is key to the development of new monoclonal antibodies. We have developed a fast and easy process to obtain mass spectrometry profiles of antibodies from culture supernatant. Treatment of the supernatant with IdeS generates three fragments of 25 kDa that can be analyzed by liquid chromatography-mass spectrometry time-of-flight (LC-MS TOF) in one run: LC, Fd, and Fc/2. This process gives rapid access to isoform and glycoform profiles. To specifically measure the fucosylation yield, we included a one-pot treatment with EndoS that removes the distal glycan heterogeneity. Our process was successfully compared with high-performance capillary electrophoresis with laser-induced fluorescence detection (HPCE-LIF), currently considered as the "gold standard" method. 

Characterization of monoclonal antibodies by a fast and easy liquid chromatography-mass spectrometry time-of-flight analysis on culture supernatant.

Insulin-degrading enzyme (IDE) is a protease that cleaves insulin and other bioactive peptides such as amyloid-β. Knockout and genetic studies have linked IDE to Alzheimer's disease and type-2 diabetes. As the major insulin-degrading protease, IDE is a candidate drug target in diabetes. Here we have used kinetic target-guided synthesis to design the first catalytic site inhibitor of IDE suitable for in vivo studies (BDM44768). Crystallographic and small angle X-ray scattering analyses show that it locks IDE in a closed conformation. Among a panel of metalloproteases, BDM44768 selectively inhibits IDE. Acute treatment of mice with BDM44768 increases insulin signalling and surprisingly impairs glucose tolerance in an IDE-dependent manner. These results confirm that IDE is involved in pathways that modulate short-term glucose homeostasis, but casts doubt on the general usefulness of the inhibition of IDE catalytic activity to treat diabetes.

Catalytic site inhibition of insulin-degrading enzyme by a small molecule induces glucose intolerance in mice.

For the last 15 years, kinetic target-guided syntheses, including in situ click chemistry, have been used as alternative methods to find ligands to therapeutically relevant proteins. In this review, a comprehensive survey of biological targets used in kinetic target-guided synthesis covers historical and recent examples. The chemical reactions employed and practical aspects, including controls, library sizes and product detection, are presented. A particular focus is on the reagents and warhead selection and design with a critical overview of the challenges encountered. As protein supply remains a key success factor, it appears that increased efforts should be taken toward miniaturization in order to expand the scope of this strategy and qualify it as a fully fledged drug discovery tool. 

Kinetic target-guided synthesis in drug discovery and chemical biology: a comprehensive facts and figures survey.

Multi-drug-resistant tuberculosis (TB) is a major public health problem, concerning about half a million cases each year. Patients hardly adhere to the current strict treatment consisting of more than 10 000 tablets over a 2-year period. There is a clear need for efficient and better formulated medications. We have previously shown that nanoparticles made of cross-linked poly-β-cyclodextrins (pβCD) are efficient vehicles for pulmonary delivery of powerful combinations of anti-TB drugs. Here, we report that in addition to being efficient drug carriers, pβCD nanoparticles are endowed with intrinsic antibacterial properties. Empty pβCD nanoparticles are able to impair Mycobacterium tuberculosis (Mtb) establishment after pulmonary administration in mice. pβCD hamper colonization of macrophages by Mtb by interfering with lipid rafts, without inducing toxicity. Moreover, pβCD provoke macrophage apoptosis, leading to depletion of infected cells, thus creating a lung microenvironment detrimental to Mtb persistence. Taken together, our results suggest that pβCD nanoparticles loaded or not with antibiotics have an antibacterial action on their own and could be used as a carrier in drug regimen formulations effective against TB.

Benoit Deprez

Institut Pasteur de Lille,
Institut National de la Santé et de la Recherche Médicale (Inserm) U1177,
Drugs and Molecules for Living Systems,
Institut Pasteur de Lille, Institut National de la Santé et de la Recherche Médicale (Inserm) U1177, Drugs and Molecules for Living Systems

Université de Lille

High-Throughput DNA Plasmid Multiplexing and Transfection Using Acoustic Nanodispensing Technology