Molecular forms of butyrylcholinesterase and obesity

This study compared obese (N = 134) and unobese (N = 92) male blood donors, regarding the relative intensity (RI) and activity of different molecular forms (G1, G2, G4 and G1-ALB) of butyrylcholinesterase (BChE, EC 3.1.1.8) found in plasma, thereby searching for an association between these variables with obesity and SNPs of exons 1 and 4 of the BCHE gene. It was shown that obese and unobese individuals do not differ in the RI of each BChE band, even when classifying the sample into three genotypes of exons 1 and 4 of the BCHE gene (-116GG/539AA, -116GG/539AT, -116GA/539AT). Although the mean BChE activity of each band was significantly higher in obese than in unobese blood donors, the proportions of BChE bands were maintained, even under the metabolic stress associated to obesity, thereby leading to infer that this proportion is somehow regulated, and may therefore be important for BChE functions.     

Biochemical and genetic analysis of butyrylcholinesterase (BChE) in a family, due to prolonged neuromuscular blockade after the use of succinylcholine

Butyrylcholinesterase (BChE) is a plasma enzyme that catalyzes the hydrolysis of choline esters, including the muscle-relaxant succinylcholine and mivacurium. Patients who present sustained neuromuscular blockade after using succinylcholine usually carry BChE variants with reduced enzyme activity or an acquired BChE deficiency. We report here the molecular basis of the BCHE gene underlying the slow catabolism of succinylcholine in a patient who underwent endoscopic nasal surgery. We measured the enzyme activity of BChE and extracted genomic DNA in order to study the promoter region and all exons of the BCHE gene of the patient, her parents and siblings. PCR products were sequenced and compared with reference sequences from GenBank. We detected that the patient and one of her brothers have two homozygous mutations: nt1615 GCA > ACA (Ala539Thr), responsible for the K variant, and nt209 GAT > GGT (Asp70Gly), which produces the atypical variant A. Her parents and two of her brothers were found to be heterozygous for the AK allele, and another brother is homozygous for the normal allele. Sequence analysis of exon 1 including 5'UTR showed that the proband and her brother are homozygous for -116GG. The AK/AK genotype is considered the most frequent in hereditary hypocholinesterasemia (44%). This work demonstrates the importance of defining the phenotype and genotype of the BCHE gene in patients who are subjected to neuromuscular block by succinylcholine, because of the risk of prolonged neuromuscular paralysis.     

Gestational diabetes mellitus (GDM) decreases butyrylcholinesterase (BChE) activity and changes its relationship with lipids

Many conditions interfere with butyrylcholinesterase (BChE) activity, e.g., pregnancy or presence of the BCHE gene variant −116A can decrease activity whereas obesity and types I and II diabetes mellitus can increase activity. In this study, we examined BChE activity, −116A and 1615A BCHE gene variants, and anthropometric and biochemical variables associated with diabetes in patients with gestational diabetes mellitus (GDM) and in healthy pregnant women. BChE activity was measured spectrophotometrically using propionylthiocholine as substrate and genotyping of the −116 and 1615 sites of the BCHE gene was done with a TaqMan SNP genotyping assay. Three groups were studied: 150 patients with GDM, 295 healthy pregnant women and 156 non-pregnant healthy women. Mean BChE activity was significantly lower in healthy pregnant women than in women from the general population and was further reduced in GDM patients. BChE activity was significantly reduced in carriers of −116A in GDM patients and healthy pregnant women. Although GDM patients had a significantly higher mean body mass index (BMI) and triglycerides than healthy pregnant women, they had lower mean BChE activity, suggesting that the lowering effect of GDM on BChE activity was stronger than the characteristic enhancing effect of increased BMI and triglycerides.     

Glutathione S-transferase mu 1 (GSTM1) and theta 1 (GSTT1) genetic polymorphisms and atopic asthma in children from Southeastern Brazil

Xenobiotics can trigger degranulation of eosinophils and mast cells. In this process, the cells release several substances leading to bronchial hyperactivity, the main feature of atopic asthma (AA). GSTM1 and GSTT1 genes encode enzymes involved in the inactivation of these compounds. Both genes are polymorphic in humans and have a null variant genotype in which both the gene and corresponding enzyme are absent. An increased risk for disease in individuals with the null GST genotypes is therefore, but this issue is controversial. The aim of this study was to investigate the influence of the GSTM1 and GSTT1 genotypes on the occurrence of AA, as well as on its clinical manifestations. Genomic DNA from 86 patients and 258 controls was analyzed by polymerase chain reaction. The frequency of the GSTM1 null genotype in patients was higher than that found in controls (60.5% versus 40.3%, p = 0.002). In individuals with the GSTM1 null genotype the risk of manifested AA was 2.3-fold higher (95%CI: 1.4-3.7) than for others. In contrast, similar frequencies of GSTT1 null and combined GSTM1 plus GSTT1 null genotypes were seen in both groups. No differences in genotype frequencies were perceived in patients stratified by age, gender, ethnic origin, and severity of the disease. These results suggest that the inherited absence of the GSTM1 metabolic pathway may alter the risk of AA in southeastern Brazilian children, although this must be confirmed by further studies with a larger cohort of patients and age-matched controls from the distinct regions of the country.     

Characterization of 12 silent alleles of the human butyrylcholinesterase (BCHE) gene.

The silent phenotype of human butyrylcholinesterase (BChE), present in most human populations in frequencies of approximately 1/100,000, is characterized by the complete absence of BChE activity or by activity <10% of the average levels of the usual phenotype. Heterogeneity in this phenotype has been well established at the phenotypic level, but only a few silent BCHE alleles have been characterized at the DNA level. Twelve silent alleles of the human butyrylcholinesterase gene (BCHE) have been identified in 17 apparently unrelated patients who were selected by their increased sensitivity to the muscle relaxant succinylcholine. All of these alleles are characterized by single nucleotide substitutions or deletions leading to distinct changes in the structure of the BChE enzyme molecule. Nine of the nucleotide substitutions result in the replacement of single amino acid residues. Three of these variants, BCHE*33C, BCHE*198G, and BCHE*201T, produce normal amounts of immunoreactive but enzymatically inactive BChE protein in the plasma. The other six amino acid substitutions, encoded by BCHE*37S, BCHE*125F, BCHE*170E, BCHE*471R, and BCHE*518L, seem to cause reduced expression of BChE protein, and their role in determining the silent phenotype was confirmed by expression in cell culture. The other four silent alleles, BCHE*271STOP, BCHE*500STOP, BCHE*FS6, and BCHE*I2E3-8G, encode BChES truncated at their C-terminus because of premature stop codons caused by nucleotide substitutions, a frame shift, or altered splicing. The large number of different silent BCHE alleles found within a relatively small number of patients shows that the heterogeneity of the silent BChE phenotype is high. The characterization of silent BChE variants will be useful in the study of the structure/function relationship for this and other closely related enzymes.     

Possible influence of BCHE locus of butyrylcholinesterase on stature and body mass index

Butyrylcholinesterase activity has been shown to be positively associated with weight and body mass index (BMI). The present study was carried out to search for an association between variants of the BCHE gene and weight, stature, and BMI on the basis of means and variances compared between nonusual variants and their respective usual controls. Individuals bearing the atypical mutation (N = 52) did not differ from their usual phenotype controls (N = 104) in these parameters. The BCHE*U/BCHE*K individuals (N = 222) presented a significantly higher BMI variance than their BCHE*U/BCHE*U controls (N = 222, F = 1.40, P = 0.012). This higher BMI variance does not seem to be an isolated effect of the K mutation, but appears to be the result of an interaction between the K allele and the usual allele, since no such difference in variance was detected between BCHE*K/BCHE*K individuals (N = 23) and their BCHE*U/BCHE*U (N = 23) controls. These data may suggest a relation between variability in the BCHE locus itself and BMI. Individuals with the BCHE UF phenotype (N = 45) showed a significantly higher mean stature (about 3 cm more; P = 0.02) than their controls with the usual phenotype (N = 135). A role in cell proliferation has been proposed for BCHE, and since growth depends on the number of mitoses, it is not unexpected that variants of this enzyme may influence body stature in different ways. This study reports the first data on the relation of BCHE alleles to anthropometric characters.     

Association of a serotonin transporter gene (SLC6A4) 5-HTTLPR polymorphism with body mass index categories but not type 2 diabetes mellitus in Mexicans

The serotonergic system has been hypothesized to contribute to the biological susceptibility to type 2 diabetes mellitus (T2DM) and body-mass index (BMI) categories. We investigate a possible association of 5-HTTLPR polymorphism (L and S alleles) in the promoter region of the serotonin transporter gene (SLC6A4) with the development of T2DM and/or higher BMI by analyzing a sample of 138 individuals diagnosed with T2DM and 172 unrelated controls from the Mexican general population. In the total sample genotypes were distributed according to Hardy-Weinberg equilibrium, and S allele frequency was 0.58. There was no statistical association between 5-HTTLPR polymorphism and the development of T2DM in this Mexican population sample (p = 0.12). Nevertheless, logistic regression analysis of the L allele and increased BMI disclosed an association, after adjusting for age, sex and T2DM (p = 0.02, OR 1.74, 95% CI: 1.079–2.808).     

Characterization of PRLR and PPARGC1A genes in buffalo (Bubalus bubalis)

More than 40 million households in India depend at least partially on livestock production. Buffaloes are one of the major milk producers in India. The prolactin receptor (PRLR) gene and peroxisome proliferators activated receptor-γ coactivator 1-alpha (PPARGC1A) gene are reportedly associated with milk protein and milk fat yields in Bos taurus. In this study, we sequenced the PRLR and PPARGC1A genes in the water buffalo Bubalus bubalis. The PRLR and PPARGC1A genes coded for 581 and 819 amino acids, respectively. The B. bubalis PRLR gene differed from the corresponding Bos taurus at 21 positions and four differences with an additional arginine at position 620 in the PPARGC1A gene were found in the amino acid sequence. All of the changes were confirmed by cDNA sequencing. Twelve buffalo-specific single nucleotide polymorphisms (SNPs) were identified in both genes, with five of them being non-synonymous.     

建鲤IGFBP 3 基因多态性对生长的影响

胰岛素样生长因子结合蛋白3(insulin-like growth factor binding protein,IGFBP3)是调节动物生长和代谢的重要基因.本实验查找了建鲤(Cyprinus carpio var.jian)IGFBP3s基因上的SNP位点.使用PCRRFLP检测了其中5个位点(IGFBP3a-I3...     

Butyrylcholinesterase Genetic Variants: Association with Cocaine Dependence and Related Phenotypes

Objective

The search for genetic vulnerability factors in cocaine dependence has focused on the role that neuroplasticity plays in addiction. However, like many other drugs, the ability of an individual to metabolize cocaine can also influence susceptibility to dependence. Butyrylcholinesterase (BChE) metabolizes cocaine, and genetic variants of the BChE gene (BCHE) alter its catalytic activity. Therefore, we hypothesize that cocaine users with polymorphisms in BCHE can show diverse addictive behaviors due to differences in effective plasma concentrations of cocaine. Those polymorphisms might also influence users to prefer one of the two main preparations (crack or powder cocaine), despite having equal access to both. The present work investigates polymorphisms in BCHE and if those genetic variants constitute risk factors for cocaine dependence and for crack cocaine use.

Methods

A total of 1,436 individuals (698 cocaine-dependent patients and 738 controls) were genotyped for three single nucleotide polymorphisms (SNPs) in BCHE: rs1803274, rs4263329, and rs4680662.

Results

For rs4263329, a nominal difference was found between cases and controls. For rs1803274 (the functional SNP), a statistically significant difference was found between patients who used crack cocaine exclusively and those who used only powder cocaine (P = 0.027; OR = 4.36; 95% CI = 1.18–16.04). Allele frequencies and genotypes related to other markers did not differ between cases and controls or between the two cocaine subgroups.

Conclusions

Our findings suggest that the AA genotype of rs1803274 is a risk factor for crack cocaine use, which is more addictive than powder cocaine use. Further studies are needed in order to confirm this preliminary result and clarify the role of BCHE and its variants in cocaine dependence.     

Single nucleotide polymorphisms in the FTO gene and their association with growth and meat quality traits in rabbits

Fat mass and obesity associated (FTO) gene is an excellent candidate to affect the fatness and growth-related traits in pig and cattle. The aim of this study was to reveal the association between FTO and growth and meat quality traits in rabbits. A total of eight coding SNPs were detected, and four SNPs of them in exon 3 were further genotyped for association analysis in 442 rabbits from three breeds, including 248 New Zealand rabbits, 92 Ira rabbits, and 102 Champagne rabbits. Because there were significant differences for the allele and genotype frequencies among breeds, the association analysis was independently conducted in each breed only for these SNPs with minor allele frequency > 5.0%. The results revealed that non-synonymous SNP c.499G > A (p.A167T) was significantly associated with body weight (BW) at 35, 70, and 84 days of age in New Zealand rabbits (P < 0.01). The CC genotype of synonymous SNP c.660T > C was significantly associated with higher BW84, average daily weight gain, and intramuscular fat content of longissimus lumborum than TT and TC genotypes in Ira rabbits (P < 0.05). There were no associations between the four SNPs and growth and meat quality traits in Champagne rabbits. Meanwhile, FTO SNPs were not associated with meat pH value. Our data indicated that FTO gene could be a candidate gene associated with growth and meat quality traits in rabbits. However, the breed-specific effect should be carefully taken into consideration.     

Nucleotide diversity and molecular evolution of the WAG-2 gene in common wheat (Triticum aestivum L) and its relatives

In this work, we examined the genetic diversity and evolution of the WAG-2 gene based on new WAG-2 alleles isolated from wheat and its relatives. Only single nucleotide polymorphisms (SNP) and no insertions and deletions (indels) were found in exon sequences of WAG-2 from different species. More SNPs and indels occurred in introns than in exons. For exons, exons+introns and introns, the nucleotide polymorphism π decreased from diploid and tetraploid genotypes to hexaploid genotypes. This finding indicated that the diversity of WAG-2 in diploids was greater than in hexaploids because of the strong selection pressure on the latter. All dn/ds ratios were < 1.0, indicating that WAG-2 belongs to a conserved gene affected by negative selection. Thirty-nine of the 57 particular SNPs and eight of the 10 indels were detected in diploid species. The degree of divergence in intron length among WAG-2 clones and phylogenetic tree topology suggested the existence of three homoeologs in the A, B or D genome of common wheat. Wheat AG-like genes were divided into WAG-1 and WAG-2 clades. The latter clade contained WAG-2, OsMADS3 and ZMM2 genes, indicating functional homoeology among them.     

Lack of association of ghrelin precursor gene variants and percentage body fat or serum lipid profiles

Ghrelin has been recognized for its involvement in food intake, control of energy homeostasis, and lipid metabolism. However, the roles of genetic variations in the ghrelin precursor gene (GHRL) on body compositions and serum lipids are not clear in humans. Our study investigated five single-nucleotide polymorphisms (SNPs) within GHRL to determine their relationship with body fat percentage (BF), trunk fat percentage (TF), lower body (legs) fat percentage (LF), and serum lipids in 1,464 subjects, which were recruited from the genetically homogeneous population of Newfoundland and Labrador (NL), Canada. Serum glucose, insulin, total cholesterol, high-density lipoprotein-cholesterol, low-density lipoprotein-cholesterol, and triglycerides were determined. Five SNPs are rs35684 (A/G: a transition substitution in exon 1), rs4684677 (A/T: a missense mutation), rs2075356 (C/T: intron), rs26802 (G/T: intron), and rs26311 (A/G: near the 3' untranslated region) of GHRL were genotyped using TaqMan validated or functionally tested SNP genotyping assays. Our study found no significant evidence of an allele or genotype association between any of the variant sites and body compositions or serum lipids. Furthermore, haplotype frequencies were not found to be significantly different between lean and obese subjects. In summary, the results of our study do not support a significant role for genetic variations in GHRL in the differences of body fat and serum lipid profiles in the NL population.     

CYP1A1 genotypes and haplotypes and risk of oral cancer: A case-control study in South Indians

The CYP1A1 gene encodes for the enzyme, aryl hydrocarbon hydroxylase, which is involved in the biotransformation of various aromatic tobacco precarcinogens. In the present study, the association between CYP1A1 gene polymorphisms (IVS1-728G > A, Thr461Asn and Ile462Val), and the risk of oral cancer, was examined among 157 patients with oral cancer and 132 age-matched controls, in a south Indian population. The strength of the association between CYP1A1 variants and oral cancer was estimated by logistic regression. It was found that Thr461Asn was not polymorphic. Both IVS1-728G > A and Ile462Val frequencies were consistent with Hardy-Weinberg equilibrium in the control group. There were no significant differences in genotype or haplotype frequencies between controls and cases with oral cancer. Hence, CYP1A1 SNPs can be considered as not being associated with oral cancer at either the genotype or haplotype levels in the population studied.     

Genes implicated in serotonergic and dopaminergic functioning predict BMI categories

Objective: This study addressed the hypothesis that variation in genes associated with dopamine function (SLC6A3, DRD2, DRD4), serotonin function (SLC6A4, and regulation of monoamine levels (MAOA) may be predictive of BMI categories (obese and overweight + obese) in young adulthood and of changes in BMI as adolescents transition into young adulthood. Interactions with gender and race/ethnicity were also examined. Methods and Procedures: Participants were a subsample of individuals from the National Longitudinal Study of Adolescent Health (Add Health), a nationally representative sample of adolescents followed from 1995 to 2002. The sample analyzed included a subset of 1,584 unrelated individuals with genotype data. Multiple logistic regressions were conducted to evaluate the associations between genotypes and obesity (BMI > 29.9) or overweight + obese combined (BMI ≥ 25) with normal weight (BMI = 18.5–24.9) as a referent. Linear regression models were used to examine change in BMI from adolescence to young adulthood. Results: Significant associations were found between SLC6A4 5HTTLPR and categories of BMI, and between MAOA promoter variable number tandem repeat (VNTR) among men and categories of BMI. Stratified analyses revealed that the association between these two genes and excess BMI was significant for men overall and for white and Hispanic men specifically. Linear regression models indicated a significant effect of SLC6A4 5HTTLPR on change in BMI from adolescence to young adulthood. Discussion: Our findings lend further support to the involvement of genes implicated in dopamine and serotonin regulation on energy balance.