Recombinant disintegrin targets alpha(v) beta(3) integrin and leads to mediator production

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Glycosomal Targets for Anti-Trypanosomatid Drug Discovery

Glycosomes are peroxisome-related organelles found in all kinetoplastid protists, including the human pathogenic species of the family Trypanosomatidae: Trypanosoma brucei, Trypanosoma cruzi and Leishmania spp. Glycosomes are unique in containing the majority of the glycolytic/gluconeogenic enzymes, but they also possess enzymes of several other important catabolic and anabolic pathways. The different metabolic processes are connected by shared co-factors and some metabolic intermediates, and their relative importance differs between the parasites or their distinct life-cycle stages, dependent on the environmental conditions encountered. By genetic or chemical means, a variety of glycosomal enzymes participating in different processes have been validated as drug targets. For several of these enzymes, as well as others that are likely crucial for proliferation, viability or virulence of the parasites, inhibitors have been obtained by different approaches such as compound libraries screening or design and synthesis. The efficacy and selectivity of some initially obtained inhibitors of parasite enzymes were further optimized by structure-activity relationship analysis, using available protein crystal structures. Several of the inhibitors cause growth inhibition of the clinically relevant stages of one or more parasitic trypanosomatid species and in some cases exert therapeutic effects in infected animals. The integrity of glycosomes and proper compartmentalization of at least several matrix enzymes is also crucial for the viability of the parasites. Therefore, proteins involved in the assembly of the organelles and transmembrane passage of substrates and products of glycosomal metabolism offer also promise as drug targets. Natural products with trypanocidal activity by affecting glycosomal integrity have been reported.

THE RETINAL TARGETS OF CENTRIFUGAL NEURONS AND THE RETINAL NEURONS PROJECTING TO THE ACCESSORY OPTIC-SYSTEM

In birds, neurons of the isthmo-optic nucleus (ION), as well as ''ectopic'' neurons, send axons to the retina, where they synapse on cells in the inner nuclear layer (INL). Previous work has shown that centrifugal axons can be divided into two anatomically distinct types depending on their mode of termination: either ''convergent'' or ''divergent'' (Ramon y Cajal, 1889; Maturana and Frenk, 1965). We show that cytochrome-oxidase histochemistry specifically labels ''convergent'' centrifugal axons and target neurons which appear to be amacrine cells, as well as three ''types'' of ganglion cells: two types found in the INL (displaced ganglion cells) and one in the ganglion cell layer. Labeled target amacrine cells have distinct darkly labeled ''nests'' of boutons enveloping the somas, are associated with labeled centrifugal fibers, and are confined to central retina. Lesions of the isthmo-optic tract abolish the cytochrome-oxidase labeling in the centrifugal axons and in the target amacrine cells but not in the ganglion cells. Cytochromeoxidase-labeled ganglion cells in the INL are large; one type is oval and similar to the classical displaced ganglion cells of Dogiel, which have been reported to receive centrifugal input; the other type is rounder. Rhodamine beads injected into the accessory optic system results in retrograde label in both types of cells, showing that two distinct types of displaced ganglion cells project to the accessory optic system in chickens. The ganglion cells in the ganglion cell layer that label for cytochrome oxidase also project to the accessory optic system. These have proximal dendrites that ramify in the outer inner plexiform layer. Neither the target amacrine cells nor either of the displaced ganglion cells are immunoreactive for the inhibitory transmitter gamma aminobutyric acid. At least some of the target amacrine cells may, however, be cholinoceptive: we found that the antibody to the alpha-7 subunit of the nicotinic ACh receptor labels a population of cells in the INL that are similar in location, size, and the presence of labeled bouton-like structures to those we find labeled with cytochrome oxidase. This antibody also labels neurons in the ION proper but not ectopic cells. In conclusion, it appears that cytochrome oxidase may be a marker for ''convergent'' centrifugal axons and at least one of their target cells in the INL.

Stem cell factor: a hemopoietic cytokine with important targets in asthma

We review evidence that Stem Cell Factor (SCF) plays an important role in the pathophysiology of asthma. SCF is produced by a wide variety of cells present in asthmatic lung, including mast cells and eosinophils. Its receptor, c-kit, is broadly expressed on mature mast cells and eosinophils. SCF promotes recruitment of mast cell progenitors into tissues, as well as their local maturation and activation. It also promotes eosinophil survival, maturation and functional activation. SCF enhances IgE-dependent release of mediators from mast cells, including histamine, leukotrienes, cytokines (TNF-alpha, IL-5, GM-CSF) and chemokines (RANTES/CCL5, MCP-1/CCL2, TARC/CCL17 e MDC/CCL22); it is required for IL-4 production in mast cells. SCF, acting in concert with IgE, also upregulates the expression and function of CC chemokine receptors in mast cells. Structural and resident airway cells express increased levels of SCF in the bronchus of asthmatic patients. In a murine model of asthma, allergen exposure increased production of SCF by epithelial cells and alveolar macrophages, which was transient and paralleled by histamine release. SCF induced long-lived airway hyperreactivity, which was prevented by local neutralization of SCF, as well as by inhibitors of the production or activity of cysteinyl-leukotrienes. Together, these observations suggest that SCF has an important role in asthma.

Molecular expression profile reveals potential biomarkers and therapeutic targets in canine endometrial lesions

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Characterization of Trypanosoma cruzi Sirtuins as Possible Drug Targets for Chagas Disease

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A glycolytic phenotype is associated with prostate cancer progression and aggressiveness: a role for monocarboxylate transporters as metabolic targets for therapy

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Current advances in antitubercular drug discovery: potent prototypes and new targets

Tuberculosis (TB) is an infectious disease caused by bacterium of the Mycobacterium genus, mainly by Mycobacterium tuberculosis (MTB). The World Health Organization aims to substantially reduce the number of cases in the coming years; however, the increased number of multidrug-resistant (MDR) and extremely drug-resistant (XDR) forms of the bacterium and the lack of treatment for latent tuberculosis are challenges to be overcome. In this review, we have identified the most potent compounds described in the literature during recent years with MIC values < 7 µM, low toxicity and a high selective index. In addition, emerging targets in MTB are presented to provide new perspectives for the discovery of new antitubercular drugs. This review aims to summarize the current advances in and promote insights into antitubercular drug discovery.