2-(2,2,2-Trifluoroethyl)-5,6-dichlorobenzimidazole derivatives as potent androgen receptor antagonists

The synthesis and in vivo SAR of N-benzyl, N-aceto, and N-ethylene ether derivatives of 2-(2,2,2-trifluoroethyl)-5,6-dichloro-benzimidazole as novel androgen receptor antagonists are described. SAR studies led to the discovery of 4-bromo-benzyl benzimidazole 17 as a more potent androgen receptor antagonist in the rat prostate (ID(50)=0.13mg/day), compared with bicalutamide (ID(50)=0.23mg/day).     

In vitro characterization of trimegestone: a new potent and selective progestin

Trimegestone (TMG) is a novel 19-norpregnane progestin under development for hormone replacement therapy and oral contraception. The objective of the current study was to characterize the potency and steroid receptor selectivity of TMG in several in vitro assays and to compare its activity to that of medroxyprogesterone acetate (MPA). TMG and MPA had a similar competitive binding affinity for human and rabbit progesterone receptor (PR). However, TMG had a significantly higher affinity for rat PR (IC(50) = 3.3 nM) than MPA (IC(50) = 53.3 nM). In T47D cells, both compounds increased alkaline phosphatase activity and cell proliferation with comparable potencies (EC(50s) of 0.1 nM and of 0.02 nM, respectively). To further characterize the progestational activity and steroid receptor selectivity, we established an immortalized human endometrial stromal cell line (HESC-T). This cell line lacks endogenous estrogen receptor (ER) and PR but does have functional glucocorticoid receptors (GR). When ER is transiently expressed in the cells, 17beta-estradiol (E(2)) induces PR, allowing the study of PR-regulated genes. In HESC-T cells expressing exogenous ER, and therefore PR, both TMG and MPA increased HRE-tk-luciferase activity tenfold with an EC(50) of 0.2 nM. In HESC-T cells without exogenous ER, and therefore no PR, TMG did not induce HRE-tk-luciferase activity, whereas MPA induced the reporter activity with an EC(50) of about 10 nM. This MPA-induced reporter activity is believed to be mediated through GR. The steroid receptor selectivity of TMG was further evaluated using the HRE-tk-luciferase assay in the human lung carcinoma cell line A549, which contains GR but no PR. In these cells TMG had no effect on luciferase activity, whereas MPA increased the reporter activity in a dose-dependent manner with an EC(50) of approximately 30 nM. Furthermore, HRE-tk-luciferase assay in mouse fibroblast cell line L929, which expresses androgen receptor (AR) but no PR, showed that TMG had weak antiandrogenic activity whereas MPA had androgenic activity. In summary, data from several in vitro assays demonstrate that TMG is a potent progestin with a better receptor selectivity profile than MPA.     

Synthesis and SAR of tetracyclic pyrroloquinolones as phosphodiesterase 5 inhibitors

The synthesis of the fused tetracyclic pyrroloquinolones 9a-i in four steps is described. The PDE5 inhibitory activities of these compounds, their selectivities against PDE1, PDE2, PDE3, PDE4 and PDE6, the preclinical pharmacokinetic assessments and the in vivo efficacy in increasing intracavernosal pressure are presented and discussed.     

A selective androgen receptor modulator with minimal prostate hypertrophic activity restores lean body mass in aged orchidectomized male rats

Androgens are required for the maintenance of normal sexual activity in adulthood and for enhancing muscle growth and lean body mass in adolescents and adults. Androgen receptor (AR) ligands with tissue selectivity (selective androgen receptor modulators, or SARMs) have potential for treating muscle wasting, hypogonadism of aging, osteoporosis, female sexual dysfunction, and other indications. JNJ-37654032 is a nonsteroidal AR ligand with mixed agonist and antagonist activity in androgen-responsive cell-based assays. It is an orally active SARM with muscle selectivity in orchidectomized rat models. It stimulated growth of the levator ani muscle with ED(50) 0.8 mg/kg, stimulating maximal growth at a dose of 3mg/kg. In contrast, it stimulated ventral prostate growth to 21% of its full size at 3mg/kg. At the same time, JNJ-37654032 reduced prostate weight in intact rats by 47% at 3mg/kg, while having no inhibitory effect on muscle. Using magnetic resonance imaging to monitor body composition, JNJ-37654032 restored about 20% of the lean body mass lost following orchidectomy in aged rats. JNJ-37654032 reduced follicle-stimulating hormone levels in orchidectomized rats and reduced testis size in intact rats. JNJ-37654032 is a potent prostate-sparing SARM with the potential for clinical benefit in muscle-wasting diseases.     

Local Knowledge and Conservation of Seagrasses in the Tamil Nadu State of India

Local knowledge systems are not considered in the conservation of fragile seagrass marine ecosystems. In fact, little is known about the utility of seagrasses in local coastal communities. This is intriguing given that some local communities rely on seagrasses to sustain their livelihoods and have relocated their villages to areas with a rich diversity and abundance of seagrasses. The purpose of this study is to assist in conservation efforts regarding seagrasses through identifying Traditional Ecological Knowledge (TEK) from local knowledge systems of seagrasses from 40 coastal communities along the eastern coast of India. We explore the assemblage of scientific and local traditional knowledge concerning the 1. classification of seagrasses (comparing scientific and traditional classification systems), 2. utility of seagrasses, 3. Traditional Ecological Knowledge (TEK) of seagrasses, and 4. current conservation efforts for seagrass ecosystems. Our results indicate that local knowledge systems consist of a complex classification of seagrass diversity that considers the role of seagrasses in the marine ecosystem. This fine-scaled ethno-classification gives rise to five times the number of taxa (10 species = 50 local ethnotaxa), each with a unique role in the ecosystem and utility within coastal communities, including the use of seagrasses for medicine (e.g., treatment of heart conditions, seasickness, etc.), food (nutritious seeds), fertilizer (nutrient rich biomass) and livestock feed (goats and sheep). Local communities are concerned about the loss of seagrass diversity and have considerable local knowledge that is valuable for conservation and restoration plans. This study serves as a case study example of the depth and breadth of local knowledge systems for a particular ecosystem that is in peril.     

Rat uterine complement C3 expression as a model for progesterone receptor modulators: characterization of the new progestin trimegestone

Progestins have a wide variety of activities in female reproduction. There are also pharmacological applications for progestins, including hormone replacement therapy and contraception. Here we report the development and characterization of the rat uterine complement component C3 mRNA as a molecular target for the evaluation of the antiestrogenic activity of progestins in the uterus. In this assay, ethinyl estradiol (EE) is used to stimulate C3 expression and progestins are then evaluated for their ability to inhibit this expression. The three reference progestins, progesterone (P4), levonorgestrel (LNG), and medroxyprogesterone acetate (MPA) blocked the increase in C3 mRNA levels induced by EE. Dexamethasone (DEX) and 17alpha-methyl testosterone did not inhibit the estrogen induced C3 mRNA levels; in fact, DEX caused a further increase in C3 mRNA levels. Finally, the antiprogestin RU486 was able to block the MPA inhibition of C3 message. RU486, like DEX, caused an increase in C3 mRNA levels above that of estrogen treatment alone. The model was also used to evaluate trimegestone (TMG), a new steroidal progestin, that has been shown to be a potent and selective progesterone receptor agonist. The activity of TMG in the rat uterine decidualization and ovulation inhibition assays was similar to MPA. However, in the C3 model, TMG caused a dose-dependent inhibition of the EE induced C3 message and was approximately five-fold more potent in this model than MPA (EC(50) of 4.7 microg/kg and 26.5 microg/kg, respectively). Therefore, TMG was a more potent antagonist of estrogenic activity in the uterine endometrium than any of the reference progestins tested and therefore may be more effective in protecting the endometrium in hormone replacement therapy.     

Leukotriene B4 receptors BLT1 and BLT2: expression and function in human and murine mast cells

Leukotriene B4 (LTB4) is a potent activator and chemoattractant for leukocytes and is implicated in several inflammatory diseases. The actions of LTB4 are mediated by two cell surface receptors, BLT1, which is predominantly expressed in peripheral blood leukocytes, and BLT2, which is expressed more ubiquitously. Recently, BLT1 expression and LTB4-dependent chemotaxis have been reported in immature mast cells (MCs). We now show the first evidence for BLT2 mRNA expression, in addition to BLT1, in murine bone marrow-derived MCs (mBMMCs) and in a human MC line (HMC-1). Protein expression of BLT1 was confirmed by mAb staining in HMC-1 cells and shown to be predominantly intracellular. Both HMC-1 cells and mBMMCs migrated to LTB4 in a dose-dependent manner in chemotaxis assays. Migration to LTB4 could be inhibited by either a BLT1- or BLT2-selective antagonist. Significant dose-dependent migration of mBMMCs also was observed to 12-(S)-hydroxyeicosotetraenoic acid, a BLT2-selective agonist, demonstrating functional BLT2 activity in these cells. Stimulation of mBMMCs with LTB4 induced transient, dose-dependent, ERK phosphorylation and changes in Akt phosphorylation. Dose-dependent ERK phosphorylation also was observed in response to 12-(S)-hydroxyeicosotetraenoic acid, indicating signaling downstream of BLT2. Pretreatment of mBMMCs with stem cell factor significantly down-regulated expression of BLT1 and BLT2 mRNA and inhibited their migration to LTB4. This study demonstrates expression of functional LTB4 receptors, both BLT1 and BLT2, in murine and human MCs and a regulatory role for stem cell factor in their expression. These receptors may mediate recruitment and accumulation of MCs in response to LTB4 production in areas of inflammation.     

Serendipitous discovery of novel imidazolopyrazole scaffold as selective androgen receptor modulators

A novel imidazolopyrazole derivative has been fortuitously discovered as potent selective androgen receptor modulator with in vivo efficacy.     

Culturable Bacterial Flora Associated with the Dinoflagellate Green Noctiluca miliaris During Active and Declining Bloom Phases in the Northern Arabian Sea

A massive algal bloom of the dinoflagellate Noctiluca miliaris (green) was located in the Northern Arabian Sea by IRS-P4-2 (OCM-II) for microbiological studies, during two consecutive cruises of February-March 2009. Culturable bacterial load during bloom were ～2–3-fold higher in comparison to non-bloom waters and ranged from 3.20?×?10⁵ to 6.84?×?10⁵?cfu?ml^?1. An analysis of the dominant heterotrophs associated with Noctiluca bloom resulted in phylogenetic and a detailed metabolic characterization of 70 bacterial isolates from an overlapping active and declining bloom phase location near north-central Arabian Sea. The active phase flora was dominated by Gram-positive forms (70.59 %), a majority of which belonged to Bacillus (35.29 %) of Firmicutes. As the bloom declined, Gram-negative forms (61.11 %) emerged dominant, and these belonged to a diverse γ-proteobacterial population consisting of Shewanella (16.67 %) and equal fractions of a Cobetia–Pseudomonas-Psychrobacter–Halomonas population (36.11 %). A Unifrac-based principal coordinate analysis of partial 16S rDNA sequences showed significant differences among the active and declining phase flora and also with reported endocytic flora of Noctiluca (red). A nonparametric multidimensional scaling (NMDS) of antibiogram helped differentiation among closely related strains. The organic matter synthesized by N. miliaris appears to be quickly utilized and remineralized as seen from the high efficiency of isolates to metabolize various complex and simple C/N substrates such as carbohydrates, proteins/amino acids, lipids, sulfide production from organic matter, and solubilize phosphates. The ability of a large fraction of these strains (50–41.67 %) to further aerobically denitrify indicates their potential for nitrogen removal from these high-organic microniches of the Noctiluca bloom in the Arabian Sea, also known for high denitrification activity. The results indicate that culturable euphotic bacterial associates of Noctiluca are likely to play a critical role in the biogeochemical ramifications of these unique seasonally emerging tropical open-water blooms of the Northern Arabian Sea.     

GO Explorer: A gene-ontology tool to aid in the interpretation of shotgun proteomics data

Background  

Spectral counting is a shotgun proteomics approach comprising the identification and relative quantitation of thousands of proteins in complex mixtures. However, this strategy generates bewildering amounts of data whose biological interpretation is a challenge.