Natural products: a continuing source of novel drug leads.

The various types of biosensors such as enzyme-based, tissue-based, immunosensors, DNA biosensors, thermal and piezoelectric biosensors have been deliberated here to highlight their indispensable applications in multitudinous fields. Some of the popular fields implementing the use of biosensors are food industry to keep a check on its quality and safety, to help distinguish between the natural and artificial; in the fermentation industry and in the saccharification process to detect precise glucose concentrations; in metabolic engineering to enable in vivo monitoring of cellular metabolism. Biosensors and their role in medical science including early stage detection of human interleukin-10 causing heart diseases, rapid detection of human papilloma virus, etc. are important aspects. Fluorescent biosensors play a vital role in drug discovery and in cancer. Biosensor applications are prevalent in the plant biology sector to find out the missing links required in metabolic processes. Other applications are involved in defence, clinical sector, and for marine applications.

Biosensors and their applications - A review.

Of the thousands of novel compounds that a drug discovery project team invents and that bind to the therapeutic target, typically only a fraction of these have sufficient ADME/Tox properties to become a drug product. Understanding ADME/Tox is critical for all drug researchers, owing to its increasing importance in advancing high quality candidates to clinical studies and the processes of drug discovery. If the properties are weak, the candidate will have a high risk of failure or be less desirable as a drug product. This book is a tool and resource for scientists engaged in, or preparing for, the selection and optimization process. The authors describe how properties affect in vivo pharmacological activity and impact in vitro assays. Individual drug-like properties are discussed from a practical point of view, such as solubility, permeability and metabolic stability, with regard to fundamental understanding, applications of property data in drug discovery and examples of structural modifications that have achieved improved property performance. The authors also review various methods for the screening (high throughput), diagnosis (medium throughput) and in-depth (low throughput) analysis of drug properties. * Serves as an essential working handbook aimed at scientists and students in medicinal chemistry * Provides practical, step-by-step guidance on property fundamentals, effects, structure-property relationships, and structure modification strategies * Discusses improvements in pharmacokinetics from a practical chemist's standpoint

Drug-Like Properties: Concepts, Structure Design and Methods from ADME to Toxicity Optimization

Control of the establishment of cell polarity is an essential function in tissue morphogenesis and renewal that depends on spatial cues provided by the extracellular environment. The molecular role of cell–cell or cell–extracellular matrix (ECM) contacts on the establishment of cell polarity has been well characterized. It has been hypothesized that the geometry of the cell adhesive microenvironment was directing cell surface polarization and internal organization. To define how the extracellular environment affects cell polarity, we analyzed the organization of individual cells plated on defined micropatterned substrates imposing cells to spread on various combinations of adhesive and nonadhesive areas. The reproducible normalization effect on overall cell compartmentalization enabled quantification of the spatial organization of the actin network and associated proteins, the spatial distribution of microtubules, and the positioning of nucleus, centrosome, and Golgi apparatus. By using specific micropatterns and statistical analysis of cell compartment positions, we demonstrated that ECM geometry determines the orientation of cell polarity axes. The nucleus–centrosome orientations were reproducibly directed toward cell adhesive edges. The anisotropy of the cell cortex in response to the adhesive conditions did not affect the centrosome positioning at the cell centroid. Based on the quantification of microtubule plus end distribution we propose a working model that accounts for that observation. We conclude that, in addition to molecular composition and mechanical properties, ECM geometry plays a key role in developmental processes.

https://www.pnas.org/content/pnas/103/52/19771.full.pdf

Anisotropy of cell adhesive microenvironment governs cell internal organization and orientation of polarity

Recognition of some of the limitations of target-based drug discovery has recently led to the renaissance of a more holistic approach in which complex biological systems are investigated for phenotypic changes upon exposure to small molecules. The subsequent identification of the molecular targets that underlie an observed phenotypic response--termed target deconvolution--is an important aspect of current drug discovery, as knowledge of the molecular targets will greatly aid drug development. Here, the broad panel of experimental strategies that can be applied to target deconvolution is critically reviewed.

Target deconvolution strategies in drug discovery

Traditional screening paradigms often focus on single targets. To facilitate drug discovery in the more complex physiological environment of a cell or organism, powerful cellular imaging systems have been developed. The emergence of these detection technologies allows the quantitative analysis of cellular events and visualization of relevant cellular phenotypes. Cellular imaging facilitates the integration of complex biology into the screening process, and addresses both high-content and high-throughput needs. This review describes how cellular imaging technologies contribute to the drug discovery process.

Cellular imaging in drug discovery

Type II diabetes and its associated complications are a major health concern of the developed world. One of the hallmarks of diabetes is insulin resistance, where secreted insulin no longer has any effect on its target tissues, namely, liver, muscle, and fat. An important therapeutic strategy is to modulate blood glucose levels using pharmacological agents. Glycogen synthase kinase-3 (GSK3) is a serine-threonine protein kinase that plays important roles in regulating glucose metabolism. It is a key negative regulator of insulin action and is an important contributing factor to insulin resistance in liver, muscle, and adipose tissue. We describe the development of a cell-based assay designed to measure glucose production in rat hepatoma cell line H4IIE liver cells in response to treatment with small molecule inhibitors, including GSK3 inhibitors. The assay is set up in a 96-well format, and glucose production is assessed using a convenient fluorescence-based readout. This disease-relevant cellular assay is...

A cellular assay for measuring the modulation of glucose production in H4IIE cells.

Glycogen synthase kinase-3 (GSK3) is a serine-threonine protein kinase that exists as two isozymes, GSK3α and GSK3β. It plays important roles in regulating cell structure, function, and survival, and dysregulation of its function is linked to disorders such as Alzheimer's disease and type II diabetes. In resting cells, GSK3 is active and regulates the function of many downstream targets, including β-catenin. We describe the development of a cell-based assay designed to measure the activity of GSK3 by directly measuring the accumulation of β-catenin in Chinese hamster ovary clone K1 (CHOK1) cells. β-Catenin levels were assessed using an antibody-based staining protocol with a luminometric readout. The assay is set up in a 96-well format. The use of GSK3 inhibitors demonstrated that this assay could be used to compare the effects of various small molecules on GSK3 inhibition in CHOK1 cells.

Karen Yeow

Papers

Cellular imaging in drug discovery

A cellular assay for measuring the modulation of glucose production in H4IIE cells.

A Cellular Assay for Measuring the Inhibition of Glycogen Synthase Kinase-3 via the Accumulation of β-Catenin in Chinese Hamster Ovary Clone K1 Cells