Association of serotonergic pathway genes with smoking cessation in a Chinese rural male population

AVPR1A main effect and OXTR-by-environment interplay in individual differences in depression level

Background

Multiple studies of depression indicated a significant role of gene-by-environment interactions; however, they are mainly limited to the examination of modulating effect of recent stressful life events. Other environmental factors occurring at different stages of ante- and postnatal development may affect the association between multiple genes and depression. The study aimed to analyze the main and haplotype-based effect of serotonergic system and HPA-axis gene polymorphisms on depression and to detect gene-by-environment interaction models explaining individual variance in depression in mentally healthy young adults from Russia.

Methods

Depression score was assessed using Beck Depression Inventory (BDI) in 623 healthy individuals (81% women; 17-25 years) of Caucasian origin (Russians, Tatars, Udmurts) from Russia. The main- and gene-based effects of 12 SNPs in SLC6A4 (5-HTTLPR, rs1042173), HTR2A (rs7322347), OXTR (rs7632287, rs2254298, rs13316193, rs53576, rs2228485, rs237911), AVPR1A (rs3803107, rs1042615), and AVPR1B (rs33911258) genes, and gene-by-environment interactions were tested with linear regression models (PLINK v.1.9) adjusted for multiple comparisons.

Results

We observed ethnicity-specific main effect of the AVPR1A rs3803107 (P = 0.003; P_FDR = 0.047) and gene-based effect of the OXTR gene (Р = 0.005; P_perm = 0.034) on BDI-measured depression, and modifying effect of paternal care on OXTR rs53576 (P = 0.004; P_FDR = 0.012) and birth order on OXTR rs237911 (P = 0.006; P_FDR = 0.018) association with depression level.

Limitations

A hypothesis driven candidate gene approach, which examined a limited number of genetic variants in a moderately large sample, was used.

Conclusions

Our preliminary findings indicate that familial environment may play a permissive role modulating the manifestation of OXTR-based depression variance in mentally healthy subjects.

Factors Predicting 6-Month Smoking Cessation in Korean Adults

The purpose of this study was to identify factors predicting 6-month smoking cessation in Korean adult smokers. This descriptive correlation study assessed levels of urine cotinine, serum cotinine, serum serotonin, and 5-hydroxyindoleacetic acid; tobacco withdrawal symptoms; and resilience among 164 Korean adult smokers. Serum cotinine levels were negatively related to resilience at six months (r = -.42, p = .019), but were positively related to the amount of smoking (r = .32, p = .008) and with the Week 6 tobacco withdrawal symptoms score (r = .48, p = .001, n = 41). Higher resilience was associated with a higher 5-HIAA concentration. Greater therapy attendance, resilience, and withdrawal symptoms explained 35.3% of the variance in 6-month smoking cessation (Nagelkerke R² = .35, p < .001, n = 76). Efforts to increase counseling attendance rates and resilience and decrease withdrawal symptoms could be useful ways to improve smoking cessation rates.

Rs9303628 and rs2054847 of SLC6A4 are protective factors for the onset of lifelong premature ejaculation among the Chinese population

The purpose of this study was to investigate whether the polymorphisms of SLC6A4 gene affect the occurrence of lifelong premature ejaculation (LPE). In this case-control study, Agena MassARRAY was used to genotype SLC6A4 polymorphisms of 91 LPE patients and 362 controls. Then, genetic model and haplotype analysis were utilised to explore the correlation between SLC6A4 polymorphisms and LPE risk. The results showed that allele T, genotype T/T and C/T-T/T of rs9303628 were significantly correlated with a decreased risk of LPE in allele (p = .009), co-dominant (p = .025) and dominant (p = .014) model respectively. Allele T and genotype C/T-T/T of rs2054847 reduced the risk of LPE in co-dominant (p = .015) and dominant (p = .030) models respectively. Furthermore, there was a significant correlation between A_rs9303628 C_rs2054847 haplotype and the decreased the risk of LPE (p = .010). In conclusion, this study firstly proved that the presence of rs9303628 and rs2054847 in SLC6A4 gene was a protective factor for the occurrence of LPE in the Chinese Han population.