Discovery and evaluation of inhibitors of human ceramidase

The ceramide/sphingosine-1-phosphate (S1P) rheostat has been hypothesized to play a critical role in regulating tumor cell fate, with elevated levels of ceramide inducing death and elevated levels of S1P leading to survival and proliferation. Ceramidases are key enzymes that control this rheostat by hydrolyzing ceramide to produce sphingosine and may also confer resistance to drugs and radiation. Therefore, ceramidase inhibitors have excellent potential for development as new anticancer drugs. In this study, we identify a novel ceramidase inhibitor (Ceranib-1) by screening a small molecule library and describe the synthesis of a more potent analogue (Ceranib-2). In a cell-based assay, both compounds were found to inhibit cellular ceramidase activity toward an exogenous ceramide analogue, induce the accumulation of multiple ceramide species, decrease levels of sphingosine and S1P, inhibit the proliferation of cells alone and in combination with paclitaxel, and induce cell-cycle arrest and cell death. In vivo, Ceranib-2 was found to delay tumor growth in a syngeneic tumor model without hematologic suppression or overt signs of toxicity. These data support the selection of ceramidases as suitable targets for anticancer drug development and provide the first nonlipid inhibitors of human ceramidase activity.     

Lack of genetic association of cholesteryl ester transfer protein polymorphisms with late onset Alzheimers disease

Dysregulation of cholesterol homeostasis may be associated with the pathogenesis of coronary artery disease (CAD) and Alzheimers disease (AD). Recently, several single nucleotide polymorphisms (SNPs) in cholesteryl ester transfer protein (CETP) were associated with altered plasma CETP concentrations, cholesterol concentrations and CAD. Hence, these CETP SNPs represent excellent candidates for evaluating association with AD. To date, one study has evaluated the association between a single CETP SNP and AD. In this study, we examined three CETP SNPs to evaluate the genetic association of CETP with late onset AD on two study cohorts: the Religious Orders Study (ROS) series, including 85 AD and 70 non-AD individuals, and the University of Kentucky (UKY) series, including 78 AD and 84 non-AD individuals. Significant association between CETP genotypes or haplotypes and late onset AD was not detected in these two study cohorts. Moreover, the CETP genotypes and haplotypes were not significantly associated with AD when the populations were stratified for the presence or absence of apolipoprotein E4 (apoE4). In summary, CETP genetic variants were not associated with AD in two series.     

Food omega-3 fatty acid intake of individuals (total, linolenic acid, long-chain) and their blood pressure: INTERMAP study

Findings from short-term randomized trials indicate that dietary supplements of omega-3 polyunsaturated fatty acids (PFA) lower blood pressure of hypertensive persons, but effect size in nonhypertensive individuals is small and nonsignificant. Data are lacking on food omega-3 PFA and blood pressure in general populations. The International Study of Macro- and Micro-nutrients and Blood Pressure (INTERMAP) is an international cross-sectional epidemiologic study of 4680 men and women ages 40 to 59 from 17 population-based samples in China, Japan, United Kingdom, and United States. We report associations of food omega-3 PFA intake (total, linolenic acid, long-chain) of individuals with blood pressure. Systolic and diastolic blood pressure were measured 8 times at 4 visits. With several models to control for possible confounders (dietary, other), linear regression analyses showed inverse relationship of total omega-3 PFA from food (percent kilocalories, from four 24-hour dietary recalls) to systolic and diastolic blood pressures. With adjustment for 17 variables, estimated systolic blood pressure/diastolic blood pressure differences with 2 standard deviation higher (0.67% kcal) omega-3 PFA were -0.55/-0.57 mm Hg (Z-score -1.33, -2.00); for 2238 persons without medical or dietary intervention, -1.01/-0.98 mm Hg (Z -1.63, -2.25); for 2038 nonhypertensive persons from this sub-cohort, -0.91/-0.92 mm Hg (Z -1.80, -2.38). For linolenic acid (largely from vegetable foods), blood pressure differences were similar, eg, for the 2238 "nonintervened" individuals, -0.97/-0.87 mm Hg (Z -1.52, -1.95); blood pressure differences were -0.32/-0.45 mm Hg for long-chain omega-3 PFA (largely from fish). In summary, food omega-3 PFA intake related inversely to blood pressure, including in nonhypertensive persons, with small estimated effect size. Food omega-3 PFA may contribute to prevention and control of adverse blood pressure levels.     

Genetic association of low density lipoprotein receptor and Alzheimer's disease

The low density lipoprotein receptor (LDLR) is an attractive candidate gene for genetic association with Alzheimer's disease (AD) because: (i) the LDLR is an apolipoprotein E (apoE) receptor, alleles of which have been associated with AD, (ii) LDLR resides at chromosome 19p13.3 within a region linked to AD, and (iii) LDLR modulates the homeostasis of cholesterol, which itself appears associated with AD. Therefore, we evaluated whether LDLR haplotypes alter the odds of AD by performing an association study examining three LDLR single nucleotide polymorphisms (SNPs) in 118 AD patients and 133 non-AD subjects. LDLR genotypes were obtained by TaqMan allelic discrimination assays. Although individual LDLR SNPs were not associated with AD, analyses of unambiguous haplotypes suggested the hypothesis that the 211 LDLR haplotype was associated with reduced odds of AD. We then evaluated this hypothesis in a second study cohort, i.e., the Religious Orders Study. These results supported the hypothesis that the 211 LDLR haplotype is associated with reduced odds of AD. Moreover, these data suggested further associations between LDLR variants and AD. Thus, LDLR variants appear significantly associated with AD and merit additional study.     

A randomized trial of brief interventions for problem and pathological gamblers

Limited research exists regarding methods for reducing problem gambling. Problem gamblers (N = 180) were randomly assigned to assessment only control, 10 min of brief advice, 1 session of motivational enhancement therapy (MET), or 1 session of MET plus 3 sessions of cognitive-behavioral therapy. Gambling was assessed at baseline, at 6 weeks, and at a 9-month follow-up. Relative to assessment only, brief advice was the only condition that significantly decreased gambling between baseline and Week 6, and it was associated with clinically significant reductions in gambling at Month 9. Between Week 6 and Month 9, MET plus cognitive-behavioral therapy evidenced significantly reduced gambling on 1 index compared with the control condition. These results suggest the efficacy of a very brief intervention for reduction of gambling among problem and pathological gamblers who are not actively seeking gambling treatment.