Postnatal intracerebroventricular exposure to neuropeptide Y causes weight loss in female adult rats

We investigated the effect of repetitive postnatal (2-7 days) intracerebroventricular administration of neuropeptide Y (NPY) on food intake and body weight gain in the 3- to 120-day-old Sprague-Dawley rats. NPY caused a 32% transient increase in body weight gain with elevated circulating insulin concentrations within 24 h. This early intervention led to the persistence of hyperinsulinemia and relative hyperleptinemia with euglycemia in the 120-day-old female alone. This perturbation was associated with 50% suppression in adult female hypothalamic NPY concentrations and a 50-85% decline in NPY immunoreactivity in the paraventricular and arcuate nuclei. This change was paralleled by a approximately 20% decline in food intake and body weight gain at 60 and 120 days. However, when exogenous NPY was stereotaxically reinjected into the paraventricular nucleus of the approximately 120-day-old adult females who were pretreated with NPY postnatally, an increase in food intake and body weight gain was noted, attesting to no disruption in the NPY end-organ responsivity. We conclude that postnatal intracerebroventricular NPY has long-lasting effects that predetermine the resultant adult phenotype in a sex-specific manner.     

Cloning,expression, and initial characterization of a novel cytokine-like gene family

We report the identification and characterization of a novel cytokine-like gene family using structure-based methods to search for novel four-helix-bundle cytokines in genomics databases. There are four genes in this family, FAM3A, FAM3B, FAM3C, and FAM3D, each encoding a protein (224-235 amino acids) with a hydrophobic leader sequence. Northern analysis indicates that FAM3B is highly expressed in pancreas, FAM3D in placenta, and FAM3A and FAM3C in almost all tissues. Immunohistochemistry showed that FAM3A is expressed prominently in the vascular endothelium, particularly capillaries. We found that FAM3A and FAM3B protein were both localized to the islets of Langerhans of the endocrine pancreas. Recombinant FAM3B protein has delayed effects on beta-cell function, inhibiting basal insulin secretion from a beta-cell line in a dose-dependent manner.     

Multi-spectroscopic,thermodynamic and molecular docking studies to investigate the interaction of eplerenone with human serum albumin

The binding of small molecular drugs with human serum albumin (HSA) has a crucial influence on their pharmacokinetics. The binding interaction between the antihypertensive eplerenone (EPL) and HSA was investigated using multi-spectroscopic techniques for the first time. These techniques include ultraviolet-visible (UV-vis) spectroscopy, Fourier-transform infrared (FTIR), native fluorescence spectroscopy, synchronous fluorescence spectroscopy and molecular docking approach. The fluorescence spectroscopic study showed that EPL quenched HSA inherent fluorescence. The mechanism for quenching of HSA by EPL has been determined to be static in nature and confirmed by UV absorption and fluorescence spectroscopy. The modified Stern–Volmer equation was used to estimate the binding constant (K_b) as well as the number of bindings (n). The results indicated that the binding occurs at a single site (K_b = 2.238 × 10³ L mol⁻¹at 298 K). The enthalpy and entropy changes (∆H and ∆S) were 58.061 and 0.258 K J mol⁻¹, respectively, illustrating that the principal intermolecular interactions stabilizing the EPL–HSA system are hydrophobic forces. Synchronous fluorescence spectroscopy revealed that EPL binding to HSA occurred around the tyrosine (Tyr) residue and this agreed with the molecular docking study. The Förster resonance energy transfer (FRET) analysis confirmed the static quenching mechanism. The esterase enzyme activity of HSA was also evaluated showing its decrease in the presence of EPL. Furthermore, docking analysis and site-specific markers experiment revealed that EPL binds with HSA at subdomain IB (site III).     

Dissection of individual functions of the Sendai virus phosphoprotein in transcription.

The Sendai virus P protein is an essential component of the viral RNA polymerase (P-L complex) required for RNA synthesis. To identify amino acids important for P-L binding, site-directed mutagenesis of the P gene changed 17 charged amino acids, singly or in groups, and two serines to alanine within the L binding domain from amino acids 408 to 479. Each of the 10 mutants was wild type for P-L and P-P protein interactions and for binding of the P-L complex to the nucleocapsid template, yet six showed a significant inhibition of in vitro mRNA and leader RNA synthesis. To determine if binding was instead hydrophobic in nature, five conserved hydrophobic amino acids in this region were also mutated. Each of these P mutants also retained the ability to bind to L, to itself, and to the template, but two gave a severe decrease in mRNA and leader RNA synthesis. Since all of the mutants still bound L, the data suggest that L binding occurs on a surface of P with a complex tertiary structure. Wild-type biological activity could be restored for defective polymerase complexes containing two P mutants by the addition of wild-type P protein alone, while the activity of two others could not be rescued. Gradient sedimentation analyses showed that rescue was not due to exchange of the wild-type and mutant P proteins within the P-L complex. Mutants which gave a defective RNA synthesis phenotype and could not be rescued by P establish an as-yet-unknown role for P within the polymerase complex, while the mutants which could be rescued define regions required for a P protein function independent of polymerase function.     

Mining of expressed sequence tag libraries of cacao for microsatellite markers using five computational tools

Expressed sequence tags (ESTs) provide researchers with a quick and inexpensive route for discovering new genes, data on gene expression and regulation, and also provide genic markers that help in constructing genome maps. Cacao is an important perennial crop of humid tropics. Cacao EST sequences, as available in the public domain, were downloaded and made into contigs. Microsatellites were located in these ESTs and contigs using five softwares (MISA, TRA, TROLL, SSRIT and SSR primer). MISA gave maximum coverage of SSRs in cacao ESTs and contigs, although TRA was able to detect higher order (>5-mer) repeats. The frequency of SSRs was one per 26.9 kb in the known set of ESTs. One-third of the repeats in EST-contigs were found to be trimeric. A few rare repeats like 21-mer repeat were also located. A/T repeats were most abundant among the mononucleotide repeats and the AG/GA/TC/CT type was the most frequent among dimerics. Flanking primers were designed using Primer3 program and verified experimentally for PCR amplification. The results of the study are made available freely online database (). Seven primer pairs amplified genomic DNA isolated from leaves were used to screen a representative set of 12 accessions of cacao.     

Stress-Induced Changes in the Expression of the Clock Protein PERIOD1 in the Rat Limbic Forebrain and Hypothalamus: Role of Stress Type,Time of Day,and Predictability

Stressful events can disrupt circadian rhythms in mammals but mechanisms underlying this disruption remain largely unknown. One hypothesis is that stress alters circadian protein expression in the forebrain, leading to functional dysregulation of the brain circadian network and consequent disruption of circadian physiological and behavioral rhythms. Here we characterized the effects of several different stressors on the expression of the core clock protein, PER1 and the activity marker, FOS in select forebrain and hypothalamic nuclei in rats. We found that acute exposure to processive stressors, restraint and forced swim, elevated PER1 and FOS expression in the paraventricular and dorsomedial hypothalamic nuclei and piriform cortex but suppressed PER1 and FOS levels exclusively in the central nucleus of the amygdala (CEAl) and oval nucleus of the bed nucleus of the stria terminalis (BNSTov). Conversely, systemic stressors, interleukin-1β and 2-Deoxy-D-glucose, increased PER1 and FOS levels in all regions studied, including the CEAl and BNSTov. PER1 levels in the suprachiasmatic nucleus (SCN), the master pacemaker, were unaffected by any of the stress manipulations. The effect of stress on PER1 and FOS was modulated by time of day and, in the case of daily restraint, by predictability. These results demonstrate that the expression of PER1 in the forebrain is modulated by stress, consistent with the hypothesis that PER1 serves as a link between stress and the brain circadian network. Furthermore, the results show that the mechanisms that control PER1 and FOS expression in CEAl and BNSTov are uniquely sensitive to differences in the type of stressor. Finally, the finding that the effect of stress on PER1 parallels its effect on FOS supports the idea that Per1 functions as an immediate-early gene. Our observations point to a novel role for PER1 as a key player in the interface between stress and circadian rhythms.     

Curcumin is an inhibitor of calcium/calmodulin dependent protein kinase II

Calcium/calmodulin dependent protein kinase II (CaMKII) is involved in the mechanisms underlying higher order brain functions such as learning and memory. CaMKII participates in pathological glutamate signaling also, since it is activated by calcium influx through the N-methyl-d-aspartate type glutamate receptor (NMDAR). In our attempt to identify phytomodulators of CaMKII, we observed that curcumin, a constituent of turmeric and its analogs inhibit the Ca²⁺-dependent and independent kinase activities of CaMKII. We further report that a heterocyclic analog of curcumin I, (3,5-bis[β-(4-hydroxy-3-methoxyphenyl)ethenyl]pyrazole), named as pyrazole-curcumin, is a more potent inhibitor of CaMKII than curcumin. Microwave assisted, rapid synthesis of curcumin I and its heterocyclic analogues is also reported.