The CRHR1 gene,trauma exposure,and alcoholism risk: a test of G × E effects

The corticotropin‐releasing hormone type I receptor (CRHR1) gene has been implicated in the liability for neuropsychiatric disorders, particularly under conditions of stress. On the basis of the hypothesized effects of CRHR1 variation on stress reactivity, measures of adulthood traumatic stress exposure were analyzed for their interaction with CRHR1 haplotypes and single‐nucleotide polymorphisms (SNPs) in predicting the risk for alcoholism. Phenotypic data on 2533 non‐related Caucasian individuals (1167 alcoholics and 1366 controls) were culled from the publically available Study of Addiction: Genetics and Environment genome‐wide association study. Genotypes were available for 19 tag SNPs. Logistic regression models examined the interaction between CRHR1 haplotypes/SNPs and adulthood traumatic stress exposure in predicting alcoholism risk. Two haplotype blocks spanned CRHR1. Haplotype analyses identified one haplotype in the proximal block 1 (P = 0.029) and two haplotypes in the distal block 2 (P = 0.026, 0.042) that showed nominally significant (corrected P < 0.025) genotype × traumatic stress interactive effects on the likelihood of developing alcoholism. The block 1 haplotype effect was driven by SNPs rs110402 (P = 0.019) and rs242924 (P = 0.019). In block 2, rs17689966 (P = 0.018) showed significant and rs173365 (P = 0.026) showed nominally significant, gene × environment (G × E) effects on alcoholism status. This study extends the literature on the interplay between CRHR1 variation and alcoholism, in the context of exposure to traumatic stress. These findings are consistent with the hypothesized role of the extra hypothalamic corticotropin‐releasing factor system dysregulation in the initiation and maintenance of alcoholism. Molecular and experimental studies are needed to more fully understand the mechanisms of risk and protection conferred by genetic variation at the identified loci .     

Does COMT genotype influence the effects of d‐amphetamine on executive functioning?

In a widely cited study, Mattay et al. reported that amphetamine (0.25 mg/kg oral, or 17 mg for a 68 kg individual) impaired behavioral and brain indices of executive functioning, measured using the Wisconsin Card Sorting Task (WCST) and N‐Back working memory task, in 6 individuals homozygous for the met allele of the val158met polymorphism in the catechol‐O‐methyltransferase (COMT) gene, whereas it improved executive functioning in 10 individuals homozygous for the more active val allele. We attempted to replicate their behavioral findings in a larger sample, using similar executive functioning tasks and a broader range of amphetamine doses. Over four sessions, n = 200 healthy normal adults received oral placebo, d‐amphetamine 5, 10, and 20 mg (average of 0.07, 0.15 and 0.29 mg/kg), under counterbalanced double‐blind conditions and completed WCST and N‐back tests of executive functioning. Amphetamine had typical effects on blood pressure and processing speed but did not affect executive functioning. COMT genotype (val158met) was not related to executive functioning under placebo or amphetamine conditions, even when we compared only the homozygous val/val and met/met genotypes at the highest dose of amphetamine (20 mg). Thus, we were not able to replicate the behavioral interaction between COMT and amphetamine seen in Mattay et al. We discuss possible differences between the studies and the implications of our findings for the use of COMT genotyping to predict clinical responses to dopaminergic drugs, and the use of intermediate phenotypes in genetic research.     

Association study of 37 genes related to serotonin and dopamine neurotransmission and neurotrophic factors in cocaine dependence

Cocaine dependence is a neuropsychiatric disorder in which both environmental and genetic factors are involved. Several processes, that include reward and neuroadaptations, mediate the transition from use to dependence. In this regard, dopamine and serotonin neurotransmission systems are clearly involved in reward and other cocaine‐related effects, whereas neurotrophic factors may be responsible for neuroadaptations associated with cocaine dependence. We examined the contribution to cocaine dependence of 37 genes related to the dopaminergic and serotoninergic systems, neurotrophic factors and their receptors through a case–control association study with 319 single nucleotide polymorphisms selected according to genetic coverage criteria in 432 cocaine‐dependent patients and 482 sex‐matched unrelated controls. Single marker analyses provided evidence for association of the serotonin receptor HTR2A with cocaine dependence [rs6561333; nominal P‐value adjusted for age = 1.9e?04, odds ratio = 1.72 (1.29–2.30)]. When patients were subdivided according to the presence or absence of psychotic symptoms, we confirmed the association between cocaine dependence and HTR2A in both subgroups of patients. Our data show additional evidence for the involvement of the serotoninergic system in the genetic susceptibility to cocaine dependence.     

Variability in the Essential‐Oil Composition of Sideritis scardica Griseb. from Native Bulgarian Populations

The essential‐oil composition of six native populations of Sideritis scardica from Bulgaria was studied by GC‐FID and GC/MS analyses. Altogether, 37 components, representing 73.1 to 79.2% of the total oil content were identified. Among them, α‐pinene (4.4–25.1%), β‐pinene (2.8–18.0%), oct‐1‐en‐3‐ol (2.3–8.0%), phenylacetaldehyde (0.5–9.5%), β‐bisabolene (1.3–11.0%), benzyl benzoate (1.1–14.3%), and m‐camphorene ( 1 ; 0.3–12.4%) were the main compounds. All samples were characterized by low contents of oxygenated mono‐ and sesquiterpenes (≤1.6 and 2.3%, resp.). Principal component analysis (PCA) and cluster analysis (CA) showed a significant variability in the chemical composition of the studied samples as well as a correlation between the oil profiles and the ecological conditions of the natural habitats of S. scardica.     

Permeation through Phospholipid Bilayers,Skin‐Cell Penetration,Plasma Stability,and CD Spectra of α‐ and β‐Oligoproline Derivatives

After a survey of the special role, which the amino acid proline plays in the chemistry of life, the cell‐penetrating properties of polycationic proline‐containing peptides are discussed, and the widely unknown discovery by the Giralt group (J. Am. Chem. Soc. 2002 , 124, 8876) is acknowledged, according to which fluorescein‐labeled tetradecaproline is slowly taken up by rat kidney cells (NRK‐49F). Here, we describe details of our previously mentioned (Chem. Biodiversity 2004 , 1, 1111) observation that a hexa‐β³‐Pro derivative penetrates fibroblast cells, and we present the results of an extensive investigation of oligo‐L ‐ and oligo‐D ‐α‐prolines, as well as of oligo‐β²h‐ and oligo‐β³h‐prolines without and with fluorescence labels ( 1 – 8 ; Fig. 1). Permeation through protein‐free phospholipid bilayers is detected with the nanoFAST biochip technology (Figs. 2–4). This methodology is applied for the first time for quantitative determination of translocation rates of cell‐penetrating peptides (CPPs) across lipid bilayers. Cell penetration is observed with mouse (3T3) and human foreskin fibroblasts (HFF; Figs. 5 and 6–8, resp.). The stabilities of oligoprolines in heparin‐stabilized human plasma increase with decreasing chain lengths (Figs. 9–11). Time‐ and solvent‐dependent CD spectra of most of the oligoprolines (Figs. 13 and 14) show changes that may be interpreted as arising from aggregation, and broadening of the NMR signals with time confirms this assumption.     

Synthesis and Evaluation of Biphenyl Compounds as Kinesin Spindle Protein Inhibitors

Kinesin spindle protein (KSP), an ATP‐dependent motor protein, plays an essential role in bipolar spindle formation during the mitotic phase (M phase) of the normal cell cycle. KSP has emerged as a novel target for antimitotic anticancer drug development. In this work, we synthesized a range of new biphenyl compounds and investigated their properties in vitro as potential antimitotic agents targeting KSP expression. Antiproliferation (MTT (=3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl‐2H‐tetrazolium bromide)) assays, combined with fluorescence‐assisted cell sorting (FACS) and Western blot studies analyzing cell‐cycle arrest confirmed the mechanism and potency of these biphenyl compounds in a range of human cancer cell lines. Structural variants revealed that functionalization of biphenyl compounds with bulky aliphatic or aromatic groups led to a loss of activity. However, replacement of the urea group with a thiourea led to an increase in antiproliferative activity in selected cell lines. Further studies using confocal fluorescence microscopy confirmed that the most potent biphenyl derivative identified thus far, compound 7 , exerts its pharmacologic effect specifically in the M phase and induces monoaster formation. These studies confirm that chemical scope remains for improving the potency and treatment efficacy of antimitotic KSP inhibition in this class of biphenyl compounds.     

Cyclopaldic Acid,Seiridin, and Sphaeropsidin A as Fungal Phytotoxins,and Larvicidal and Biting Deterrents against Aedes aegypti (Diptera: Culicidae): Structure?Activity Relationships

Aedes aegypti L. is the major vector of the arboviruses responsible for dengue fever, one of the most devastating human diseases. From a preliminary screening of fungal phytotoxins, cyclopaldic acid ( 1 ), seiridin ( 2 ), sphaeropsidin A ( 4 ), and papyracillic acid ( 5 ) were evaluated for their biting deterrent and larvicidal activities against Ae. aegypti L. Because compounds 1, 2, 4 , and 5 exhibited mosquito biting deterrent activities and 1 and 4 demonstrated larvicidal activities, further structure? activity relationship studies were initiated on these toxins. In biting‐deterrence bioassays, 1, 2, 4 , and 5 , 3,8‐didansylhydrazone of cyclopaldic acid, 1F , 5‐azidopentanoate of cyclopaldic acid A, 1G , the reduced derivative of cyclopaldic acid, 1 H , isoseiridin ( 3 ), 2′‐O‐acetylseiridin ( 2A ), 2′‐oxoseiridin ( 2C ), 6‐O‐acetylsphaeropsidin A ( 4A ), 8,14‐methylensphaeropsidin A methyl ester ( 4B ), and sphaeropsidin B ( 4C ) showed activities higher than the solvent control. Sphaeropsidin B ( 4C ) was the most active compound followed by 2A , while the other compounds were less active. Biting‐deterrence activity of compound 4C was statistically similar to DEET. In the larvicidal screening bioassays, only compounds 1 and 4 demonstrated larvicidal activities. Based on LD₅₀ values, compound 4 (LD₅₀ 36.8 ppm) was significantly more active than compound 1 (LD₅₀ 58.2 ppm). However, the activity of these compounds was significantly lower than permethrin.