No leucine(7)-to-proline(7) polymorphism in the signal peptide of neuropeptide Y in Japanese population or Japanese with alcoholism

Association between neuropeptide Y gene polymorphisms and alcohol dependence: a case-control study in two independent populations

BACKGROUND

Alcohol dependence is a chronic, progressive neurobiological brain disorder. Previous research reported an inverse association between ethanol drinking and cerebral neuropeptide Y (NPY) levels. There are conflicting results of studies on NPY gene polymorphisms in association with alcohol dependence in humans.

METHODS

To assess the role of the NPY gene in alcohol dependence, we genotyped three polymorphisms--in a sample of 195 subjects from the Kota population (80 alcohol dependence and 115 controls) and 141 subjects from the Badaga population (80 alcohol dependence and 61 controls). Phenotype was defined based on the DSM-IV criteria. Genotyping was performed using sequencing. Association of the NPY gene with alcohol dependence was tested by using logistic regression and haplotype analyses and linkage disequilibrium.

RESULTS

All three polymorphisms were found to be in the Hardy-Weinberg equilibrium in both populations. The results of our study reveal a significant association between G1258A and alcohol dependence in both the Kota and Badaga populations. The linkage disequilibrium between the markers is not strong or significant. Haplotype analysis also did not show significant association between the NPY gene and alcohol dependence.

CONCLUSION

These data support the hypothesis that alcohol dependence is influenced by the NPY G1258A polymorphism in Indian populations.

Association between neuropeptide Y gene and its receptor Y1 gene and methamphetamine dependence

AIMS

Neuropeptide Y (NPY) is a 36-amino acid peptide that is widely distributed in the brain, adrenal medulla, and sympathetic nervous system. Several lines of evidence suggest a possible involvement of the NPY system in the physiological effects of several classes of abused substances including alcohol, phencyclidine, cocaine, and marijuana and in endogenous psychosis. Accordingly, it was hypothesized that the NPY system may also be involved in methamphetamine dependence or psychosis.

METHODS

The single nucleotide polymorphisms rs16147 of the NPY gene (-485C>T) and rs7687423 of the NPY receptor Y1 (NPY1R) gene were analyzed in 222 patients with methamphetamine dependence and psychosis and 288 age- and gender-matched controls.

RESULTS

Genotypic distribution of the NPY1R gene showed a significant association with methamphetamine dependence and psychosis (P = 0.04), whereas the NPY gene had no significant association with them.

CONCLUSION

It is possible that genetic variants of the NPY1R gene affect the NPY-NPY receptor type Y1 signaling system in the brain, which may result in susceptibility to methamphetamine dependence or the development of methamphetamine psychosis, but the present findings need to be confirmed on replication.

Allelic variation in the NPY gene in 14 Indian populations

NPY is a 36-aminoacid peptide expressed in several areas of the nervous system. Neuropeptide Y (NPY) receptors represent a widely diffused system that is involved in the regulation of multiple biological functions. The human NPY gene is located in chromosome 7. The functional significance of coding Leu7Pro polymorphism in the signal peptide of preproNPY is known. Six hundred and fifty four individuals of 14 ethnic Indian populations were screened for three mutations in the NPY gene, including Leu7Pro. We found that the Pro7 frequencies among the studied populations were much higher than in previous studies from other parts of the world. The highest allele frequency of Pro7 was detected in the Kota population in the Nilgiri Hill region of south India, and this may reflect a founder event in the past or genetic drift. All populations followed the Hardy-Weinberg equilibrium for the assayed markers. A total of five haplotypes were observed, only two of which were found to occur with a high frequency in all populations. No linkage disequilibrium (LD) was observed across the tested alleles in any population with the exception of Leu7Pro and Ser50Ser in the Badaga population (chi(2) = 13.969; p = 0.0001).

The T1128C polymorphism of neuropeptide Y gene in a chinese population

BACKGROUND

Several papers have shown that the T1128C polymorphism of the neuropeptide Y (NPY) gene was related to certain diseases and disorders. However, the allele frequency of the 1128C showed significant differences among some populations with different genetic backgrounds, being absent in Japanese and Korean populations. Therefore, this present study was aimed to explore whether the T1128C polymorphism of the NPY gene exists in a Chinese population.

METHODS

A total of 304 newly diagnosed inpatients with coronary heart disease (CHD) were selected as the subjects in the present study. Polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) analysis was performed to detect the T1128C polymorphism.

RESULTS

Of the 304 CHD patients, only one patient showed the T1128/C1128 genotype in the NPY gene, the others were all the T1128/T1128 genotype.

CONCLUSIONS

The T1128C polymorphism of the NPY gene is population specific and extremely low in a Chinese population.

Association analysis of the polymorphism T1128C in the signal peptide of neuropeptide Y in a Swedish hypertensive population

OBJECTIVE

The neuropeptide Y (NPY) signal peptide polymorphism T1128C has been linked to several risk factors for cardiovascular disease. The aim of the present study was to evaluate the significance of this polymorphism for cardiovascular and cerebrovascular disease outcome.

DESIGN

In a prospective study cohort, 1032 hypertensive patients (174 myocardial infarction and 170 stroke patients and 688 matched controls) were analysed for the T1128C polymorphism in the NPY gene.

METHODS

The dynamic allele specific hybridization (DASH) method was used for genotyping. Serum from the same participants was analysed for total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL) and triglycerides.

RESULTS

The frequency of the NPY T1128C polymorphism was 8.4% among patients with a myocardial infarction or stroke, as compared to 5.1% in the control group (P = 0.040). The difference remained significant after adjustment for the cardiovascular risk factors age, sex, smoking status, body mass index, systolic and diastolic blood pressure, presence of diabetes, total cholesterol, HDL, LDL and triglycerides.

CONCLUSIONS

The present study indicates that the NPY T1128C polymorphism is an independent predictor for myocardial infarction and stroke in a Swedish hypertensive population.

Association between a novel polymorphism in the promoter region of the neuropeptide Y gene and schizophrenia in humans

Hypoactivity of neuropeptide Y (NPY) is thought to be involved in the pathophysiology of schizophrenia, because post-mortem brain studies revealed a decrease of the NPY in schizophrenia, and antipsychotic treatments increase the NPY in animal brains and in cerebrospinal fluid of patients. We performed genetic analysis of the NPY gene in schizophrenia. Mutation screening of the gene detected nine single nucleotide polymorphisms, of which we typed a -485C>T variation from potential functional relevance. The -485T allele was overly represented in the disease group (P=0.0043). An in vitro promoter assay revealed that a C to T change at nt -485 significantly reduced transcriptional activity. These results suggest that the -485T allele in NPY may confer susceptibility to schizophrenia by decreasing the neuropeptide in brains.

Association of leucine 7 to proline 7 polymorphism in the preproneuropeptide Y with serum lipids in patients with coronary heart disease

Leucine 7 (Leu7) to proline 7 (Pro7) substitution in the neuropeptide Y (NPY) gene has been associated with higher serum total and low-density lipoprotein (LDL) cholesterol levels, particularly in obese subjects. We investigated the frequency of the Pro7 allele and the association of the polymorphism with serum lipid levels in patients with coronary heart disease (CHD). A total of 414 CHD patients (mean age 61 years, range 33-74) participated in the cross-sectional EUROASPIRE study. Of the subjects 39% used lipid-lowering drugs. The frequency of the Pro7 allele in CHD patients (0.082) did not differ from that in control subjects (0.071). The mean (+/-SD) serum total cholesterol concentration was higher in women with the Pro7 allele (7.57 +/- 0.57 mmol/L, n = 8) than in women with the Leu7Leu genotype (6.69 +/- 1.01 mmol/L, n = 69, P = 0.019), when subjects using lipid-lowering medication were excluded. In contrast, serum total cholesterol concentration did not significantly differ between the genotypes in men. The Leu7Pro polymorphism was not associated with serum LDL, high-density lipoprotein (HDL) cholesterol, and triglyceride concentrations. In conclusion, the Pro7 allele in the NPY gene was associated with higher serum total cholesterol concentration only in women with CHD who did not use lipid-lowering drugs.