Conformationally restricted novel pyrazole derivatives: synthesis of 1,8-disubstituted 5,5-dimethyl-4,5-dihydro-1H-benzo[g]indazoles as a new class of PDE4 inhibitors

A number of novel 1,8-disubstituted 5,5-dimethyl-4,5-dihydro-1H-benzo[g]indazoles based on a conformationally restricted pyrazole framework have been designed as potential inhibitors of PDE4. All these compounds were readily prepared by using simple chemistry strategy. The in vitro PDE4B inhibitory properties and molecular modeling studies of some of the compounds synthesized along with the X-ray single crystal data of a representative compound is presented.     

Acyl derivatives of boswellic acids as inhibitors of NF-κB and STATs

Boswellic acid acylates including their epimers were synthesized and screened against a panel of human cancer cell lines. They exhibited a range of cytotoxicity against various human cancer cell lines thereby leading to the development of a possible SAR. One of the identified lead compounds was found to be an inhibitor of the NF-κB and STAT proteins, warranting further investigations to be developed into a potential anticancer lead.     

Usual populations, unusual individuals: insights into the behavior and management of asian elephants in fragmented landscapes

Background

A dearth in understanding the behavior of Asian elephants (Elephas maximus) at the scale of populations and individuals has left important management issues, particularly related to human-elephant conflict (HEC), unresolved. Evaluation of differences in behavior and decision-making among individual elephants across groups in response to changing local ecological settings is essential to fill this gap in knowledge and to improve our approaches towards the management and conservation of elephants.

Methodology/Principal Findings

We hypothesized certain behavioral decisions that would be made by Asian elephants as reflected in their residence time and movement rates, time-activity budgets, social interactions and group dynamics in response to resource availability and human disturbance in their habitat. This study is based on 200 h of behavioral observations on 60 individually identified elephants and a 184-km² grid-based survey of their natural and anthropogenic habitats within and outside the Bannerghatta National Park, southern India during the dry season. At a general population level, the behavioral decisions appeared to be guided by the gender, age and group-type of the elephants. At the individual level, the observed variation could be explained only by the idiosyncratic behaviors of individuals and that of their associating conspecific individuals. Recursive partitioning classification trees for residence time of individual elephants indicated that the primary decisions were taken by individuals, independently of their above-mentioned biological and ecological attributes.

Conclusions/Significance

Decision-making by Asian elephants thus appears to be determined at two levels, that of the population and, more importantly, the individual. Models based on decision-making by individual elephants have the potential to predict conflict in fragmented landscapes that, in turn, could aid in mitigating HEC. Thus, we must target individuals, in addition to populations, in our efforts to manage and conserve this threatened species, particularly in human-dominated landscapes.     

Delving into somatic variation in sporadic melanoma

Melanoma, the most aggressive form of skin cancer, has increased in incidence more rapidly than any other cancer. The completion of the human genome project and advancements in genomics technologies has allowed us to investigate genetic alterations of melanoma at a scale and depth that is unprecedented. Here, we survey the history of the different approaches taken to understand the genomics of melanoma - from early candidate genes, to gene families, to genome-wide studies. The new era of whole-exome and whole-genome sequencing has paved the way for an in-depth understanding of melanoma biology, identification of new therapeutic targets, and development of novel personalized therapies for melanoma.     

The cruciferous phytoalexins rapalexin A, brussalexin A and erucalexin: chemistry and metabolism in Leptosphaeria maculans

The interactions of the cruciferous phytoalexins rapalexin A (1), brussalexin A (2) and erucalexin (3) with the fungal plant pathogen Leptosphaeria maculans were analyzed and their inhibitory activities against this pathogen were determined. The reaction of L. maculans to N-methyl S-(indolyl-3-methyl)carbamodithioate, an analogue of brussalexin A, was also investigated. Rapalexin A was resistant to metabolism and was the most inhibitory of all compounds tested, suggesting that increasing concentrations of rapalexin A in Brassica species would improve their disease resistance to L. maculans. By contrast, erucalexin was quickly detoxified by reduction to yield 3-dihydroerucalexins. The relative configurations of the diastereomeric mixture of dihydroerucalexins were established by 1D (1)H nuclear Overhauser enhancement spectroscopy (NOE). Brussalexin A was chemically unstable decomposing mainly to indolyl-3-methanol, a product with anti-cancer properties. For this reason, brussalexin A might be of interest to use as a prodrug.     

Paradoxical role of C1561T glutamate carboxypeptidase II (GCPII) genetic polymorphism in altering disease susceptibility

Although olfaction could play a crucial role in underwater habitats by allowing fish to sense a variety of nonvolatile chemical signals, the importance of olfaction in species-rich cichlids is still controversial. In particular, examining whether cichlids rely on olfaction for reproduction is of primary interest to understand the mechanisms of speciation. In the present study, we explored the V1R (also known as ora) genes, which are believed to encode reproductive pheromone receptors in fish, in the genomes of Lake Victoria cichlids. By screening a bacterial artificial chromosome library, we identified all six intact V1R genes (V1R1 to V1R6) that have been reported in other teleost fish. Furthermore, RT-PCR and in situ hybridization analyses showed that all of the V1R genes were expressed in the olfactory epithelium, indicating that these receptors are functional in cichlids. These observations indicate that cichlids use V1R-mediated olfaction in some ways for their social behaviors.     

Identification of adenovirus serotype 5 hexon regions that interact with scavenger receptors

Most of an intravenous dose of species C adenovirus serotype 5 (Ad5) is destroyed by liver Kupffer cells. In contrast, another species C virus, Ad6, evades these cells to mediate more efficient liver gene delivery. Given that this difference in Kupffer cell interaction is mediated by the hypervariable (HVR) loops of the virus hexon protein, we genetically modified each of the seven HVRs of Ad5 with a cysteine residue to enable conditional blocking of these sites with polyethylene glycol (PEG). We show that these modifications do not affect in vitro virus transduction. In contrast, after intravenous injection, targeted PEGylation at HVRs 1, 2, 5, and 7 increased viral liver transduction up to 20-fold. Elimination or saturation of liver Kupffer cells did not significantly affect this increase in the liver transduction. In vitro, PEGylation blocked uptake of viruses via the Kupffer cell scavenger receptor SRA-II. These data suggest that HVRs 1, 2, 5, and 7 of Ad5 may be involved in Kupffer cell recognition and subsequent destruction. These data also demonstrate that this conditional genetic-chemical mutation strategy is a useful tool for investigating the interactions of viruses with host tissues.     

Temperature can entrain egg laying rhythm of Drosophila but may not be a stronger zeitgeber than light

In Drosophila multiple circadian oscillators and behavioral rhythms are known to exist, yet most previous studies that attempted to understand circadian entrainment have focused on the activity/rest rhythm and to some extent the adult emergence rhythm. Egg laying behavior of Drosophila females also follows circadian rhythmicity and has been seen to deviate substantially from the better characterized rhythms in a few aspects. Here we report the findings of our study aimed at evaluating how circadian egg laying rhythm in fruit flies Drosophila melanogaster entrains to time cues provided by light and temperature. Previous studies have shown that activity/rest rhythm of flies entrains readily to light/dark (LD) and temperature cycles (TC). Our present study revealed that egg laying rhythm of a greater percentage of females entrains to TC compared to LD cycles. Therefore, in the specific context of our study this result can be taken to suggest that egg laying clocks of D. melanogaster entrains to TC more readily than LD cycles. However, when TC were presented along with out-of-phase LD cycles, the rhythm displayed two peaks, one occurring close to lights-off and the other near the onset of low temperature phase, indicating that upon entrainment by TC, LD cycles may be able to exert a greater influence on the phase of the rhythm. These results suggest that temperature and light associatively entrain circadian egg laying clocks of Drosophila.     

Regulation and function of the two-pore-domain (K2P) potassium channel Trek-1 in alveolar epithelial cells

Hyperoxia can lead to a myriad of deleterious effects in the lung including epithelial damage and diffuse inflammation. The specific mechanisms by which hyperoxia promotes these pathological changes are not completely understood. Activation of ion channels has been proposed as one of the mechanisms required for cell activation and mediator secretion. The two-pore-domain K(+) channel (K2P) Trek-1 has recently been described in lung epithelial cells, but its function remains elusive. In this study we hypothesized that hyperoxia affects expression of Trek-1 in alveolar epithelial cells and that Trek-1 is involved in regulation of cell proliferation and cytokine secretion. We found gene expression of several K2P channels in mouse alveolar epithelial cells (MLE-12), and expression of Trek-1 was significantly downregulated in cultured cells and lungs of mice exposed to hyperoxia. Similarly, proliferation cell nuclear antigen (PCNA) and Cyclin D1 expression were downregulated by exposure to hyperoxia. We developed an MLE-12 cell line deficient in Trek-1 expression using shRNA and found that Trek-1 deficiency resulted in increased cell proliferation and upregulation of PCNA but not Cyclin D1. Furthermore, IL-6 and regulated on activation normal T-expressed and presumably secreted (RANTES) secretion was decreased in Trek-1-deficient cells, whereas release of monocyte chemoattractant protein-1 was increased. Release of KC/IL-8 was not affected by Trek-1 deficiency. Overall, deficiency of Trek-1 had a more pronounced effect on mediator secretion than exposure to hyperoxia. This is the first report suggesting that the K(+) channel Trek-1 could be involved in regulation of alveolar epithelial cell proliferation and cytokine secretion, but a direct association with hyperoxia-induced changes in Trek-1 levels remains elusive.