Current Drug Discovery Technologies - Volume 4, Issue 1, 2007

Lipases play fundamental roles in biological processes since hydrolysis of triacylglycerols and cholesteryl esters is a key event in energy homeostasis of animals. Perturbations in the metabolism and the cellular retention of lipids result in common diseases such as obesity, type 2 diabetes, and atherosclerosis. The introduction of active site-directed chemical probes for enzymatic activity profiling in complex mixtures, known as activity-based proteomics, has greatly facilitated and accelerated global analysis and functional annotation of lipolytic proteins. Here we review probe design and application for discovery and discrimination of lipolytic and esterolytic enzymes. These probes are usually detected by their fluorescent or affinity tags and their protein targets are analyzed using established proteomics techniques. Moreover, microarray technologies can be applied for higher throughput screenings of enzyme or probe specificity.

Human immunodeficiency virus (HIV)-1 Nef is a regulatory protein critically involved in AIDS pathogenesis. We previously demonstrated that extracellular Nef is efficiently internalized by human primary monocyte-derived macrophages (MDMs), thereby activating a number of transcription factors including STATs, MAPKs, IRF-3, and NF-κB. Such an activation state leads to the release of inflammatory factors whose paracrine effects deserve deep consideration. Here, we demonstrate that quiescent CD4 lymphocytes undergo cell activation when cultivated in supernatants from autologous MDMs treated with extracellular wt Nef but not with its counterpart mutated in the 72PxxP75 polyproline domain. Of a pathogenetic relevance, this effect coupled with the sensitization of quiescent CD4 lymphocytes to HIV-1 infection. By microarray assay, we found that the CCL24/eotaxin-2 gene was up-regulated in MDMs treated with wt Nef but not with the 72AxxA75 mutant. In addition, the higher transcription activity correlated with a significant increase of the CCL24/Eotaxin-2 release. Finally, we observed that anti-CCL24/eotaxin-2 antibodies efficiently neutralized the stimulatory effect on CD4 lymphocytes of supernatants from MDMs treated with extracellular Nef. Overall, these data support the idea that CCL24/eotaxin-2 is part of the mechanism of CD4 lymphocyte activation paracrinally induced by Nef.

Most oncogenes encode activators of transcription factors or transcription factors themselves. Transcription factors that are induced by growth stimuli are, in contrast to transcription factors that regulate house keeping genes, tightly regulated and only active, when a stimulus (e.g. cytokines or other growth factors) is given. Examples of such transcription factors are members of the jun, fos, myc, NFkB and STAT gene families. In cancer cells this regulation is interrupted, resulting in constitutive activities of transcription factors that are normally silent. This in turn results in the increased expression of target genes that are necessary for growth and protection from apoptosis. Since inducible transcription factors are activated by specific pathways, the identification of unusual constitutively active transcription factors also identifies the involved signal transduction pathway. Inhibitors of the components of these pathways may be effective anti-cancer agents, as they interrupt the abnormal signalling and in cancer cells. We applied this strategy for two forms of cutaneous T cell lymphomas and identified several groups of agents that may be the prototypes of new drugs to fight these diseases.

An investigation of the controlled release profile of mono-layered formulations of the hormone melatonin in modified aqueous media is described. The tablets used were comprised of hydroxypropylmethylcellulose (HPMC K15M) and sodium alginate with melatonin (fully soluble in the dioctyl sulfosuccinate (DSS) containing simulated intestinal solution). Three different sets of tablets (diameters 7.5, 10.0 and 13.0 mm) were tested with respect to the influence of their sizes on the hormone's release; the general trend observed was that tablets with larger surface area values had lower % release. A decrease in the value of Wo, obtained from the ratio [H2O]/[DSS], results to the predominance of DSS conformers in the aqueous media, which are less likely to solubilize melatonin effectively.

Diabetes mellitus (DM) is a progressive disease characterized by insulin deficiency and insulin resistance or both. The fasting and post-prandial blood glucose is elevated, exposing the patient to acute and chronic complications (micro- and macro-vascular) leading to blindness, kidney failure, heart disease, stroke and amputations. Improving glycemic control has been demonstrated to lower the risk of these complications. Owing to the progressive nature of the disease, an evolving treatment strategy is necessary to maintain glycemic control. Varieties of new pharmacologic interventions are developed in past 5 years to treat people with diabetes. Several studies have been carried out covering different aspects of pharmacological interventions (newer and old drugs) along with the effects of weight loss, diet and exercise. Two categories of drugs have been used for the treatment of Diabetes Mellitus: the insulin and oral agents. Insulin analogues are molecules that differ from human insulin in amino acid sequence but bind to the insulin receptors and act similarly in function. This article provides an update of pharmacologic interventions for diabetes with practical overview of the new drug options, new insulin analogues, pharmacology, clinical efficacy, safety, dosing, cost, with specific examples of each and their background and side effects used to achieve tight glucose control. These agents have distinct characteristics that help in their selection for the treatment of type 1 and type 2 diabetes.

The availability of complete genome sequences and the wealth of large-scale biological datasets provide an unprecedented opportunity to elucidate the genetic basis of human diseases. Therapeutically relevant targets should be both ‘druggable’ and ‘disease modifying’. In this review we examine the application of computational biology towards the exploration of druggability, targetability and evolutionary conservation of human disease genes. These analyses could have a tremendous potential for systematic in silico drug target identification in the post-genomic era.

Except for few cases, chemotherapeutic toxicity is in general influenced by multiple genetic factors and nongenetic factors including age, sex and drug-drug interactions. The manifestations of adverse drug reactions differ between men and women. In particular, women experience greater toxicity from certain chemotherapeutic drugs than men. Sexrelated factors are likely to play an increasing role in drug development and therapeutic decision-making in the future. The sex-selective toxicity could be attributed to sex-related differences in pharmacokinetic and pharmacodynamic properties of these drugs. Systematic pharmacogenomic investigation into sex difference in chemotherapeutic toxicity potentially presents an opportunity to assess the effects of multiple genetic factors or gene networks on sex-related differences in the toxicity of anti-cancer drugs. A thorough understanding of the interactions between sex, drug and gene will provide valuable insights in assessing the susceptibility of an individual to chemotherapy-induced toxicity, predicting the sex-related effects for any anticancer drug and ultimately achieving the goal of personalized cancer therapy.