Sequence analysis of five exons of SLC6A4 gene in Mexican patients with anorexia nervosa and bulimia nervosa.

BACKGROUND: Accumulating evidence indicates that alterations in the serotonin system are related to changes in eating behavior. The serotonin transporter is encoded by the SLC6A4 gene and has been an interesting candidate for anorexia nervosa- restrictive type (AN-R) and bulimia nervosa (BN). Interestingly, functional variants have been identified in the coding region that could contribute to understand the role of this gene in eating disorders. The aim was to identify genetic variants in five exons of SLC6A4 gene using Sanger-sequencing in anorexia nervosa-restrictive and bulimia nervosa patients, and a control group. METHOD: The sample consisted of 86 patients and 50 control subjects. We obtained DNA samples from all subjects and performed Sanger-sequence analysis of the 1, 2, 3, 8 and 9 exons. The sequences were compared with the reference sequence of the SLC6A4 gene. RESULTS: The sequence analysis of the five exons of the gene identified several variants. In the AN-R, we observed two novel variants (g.130delA and c.1740G > A), three synonymous variants (rs57172732, rs55908624, rs74478645) and a missense variant (L90F) reporting a probably deleterious and damaging variant. In BN, we identified two novel variants (g.295C > G and c.1725G > A), and the non-synonymous (rs28914832/I425V), reported as benign. Interestingly, we observed the 425V variant in three patients in the BN, variant that previously was reported in patients with a spectrum obsessive-compulsive disorder. CONCLUSION: The results of our study suggest that variants of the SLC6A4 gene are related with a possible damaging or gain-of-function and may be involved in the susceptibility to AN-R and BN patients. However, the present findings should be considered as preliminary until replicated in large samples.

Isolation, Identification and Partial Characterization of a Lactobacillus casei Strain with Bile Salt Hydrolase Activity from Pulque.

The aim of this study was to isolate, from pulque, Lactobacillus spp. capable of survival in simulated gastrointestinal stress conditions. Nine Gram-positive rods were isolated; however, only one strain (J57) shared identity with Lactobacillus and was registered as Lactobacillus casei J57 (GenBank accession: JN182264). The other strains were identified as Bacillus spp. The most significant observation during the test of tolerance to simulated gastrointestinal conditions (acidity, gastric juice and bile salts) was that L. casei J57 showed a rapid decrease (p ≤ 0.05) in the viable population at 0 h. Bile salts were the stress condition that most affected its survival, from which deoxycholic acid and the mix of bile salts (oxgall) were the most toxic. L. casei J57 showed bile salt hydrolase activity over primary and secondary bile salts as follows: 44.91, 671.72, 45.27 and 61.57 U/mg to glycocholate, taurocholate, glycodeoxycholate and taurodeoxycholate. In contrast, the control strain (L. casei Shirota) only showed activity over tauroconjugates. These results suggest that L. casei J57 shows potential for probiotic applications.