Polimorfismos en el gen de la proteína transportadora de serotonina (SERT) en pacientes con hipertensión arterial pulmonar

SLC6A4 gene L/S polymorphism and susceptibility to pulmonary arterial hypertension: a meta-analysis

Objective

To investigate the association between the solute carrier family 6 member 4 (SLC6A4) gene L/S polymorphism and pulmonary arterial hypertension (PAH).

Methods

The relevant literature was retrieved from the PubMed® database and the data were extracted. STATA® version 12.0 software was used to calculate pooled odds ratios (ORs) and 95% confidence intervals (CI).

Results

Eight case–control studies qualified for inclusion in the meta-analysis. These studies included 1215 cases and 936 control subjects. There was no significant association between the SLC6A4 gene L/S polymorphism and PAH risk in the total population (LL versus SS: OR 1.83, 95% CI 0.95, 3.51; LS versus SS: OR 1.37, 95% CI 0.93, 2.02; dominant model: OR 1.38, 95% CI 0.97, 1.97; recessive model: OR 1.54, 95% CI 0.84, 2.83). Subgroup analysis based on study quality scores and Hardy–Weinberg equilibrium also showed no significant association.

Conclusion

The findings of this meta-analysis suggest that the SLC6A4 gene L/S polymorphism is unlikely to be related to PAH risk. Well-designed studies with more participants will be required to validate these results.

Interaction of neurotransmitters and neurochemicals with lymphocytes

Neurotransmitters and neurochemicals can act on lymphocytes by binding to receptors expressed by lymphocytes. This review describes lymphocyte expression of receptors for a selection of neurotransmitters and neurochemicals, the anatomical locations where lymphocytes can interact with neurotransmitters, and the effects of the neurotransmitters on lymphocyte function. Implications for health and disease are also discussed.

Analysis of Angiotensin Converting Enzyme, Endothelial Nitric Oxide Synthase & Serotonin Gene Polymorphisms among Atrial Septal Defect Subjects with and without Pulmonary Arterial Hypertension

Genetic polymorphisms are variations in DNA sequences which can influence either disease susceptibility, severity, or prognosis. Pulmonary arterial hypertension (PAH) is one of the complications that occurs in certain patients who have atrial septal defect (ASD). This study seeks to determine the association of gene polymorphisms with the pathogenesis of PAH in ASD patients. This study was conducted on 30 ASD patients with PAH, and 50 ASD patients who were not diagnosed with PAH. All respondents were Malay. Patients were selected based on stringent inclusion and exclusion criteria. Molecular analyses were done to detect the genetic polymorphisms of angiotensin converting enzyme (ACE I/D), serotonin transporter (5-HTTLPR), endothelial nitric oxide synthase (eNOS) G894T, and eNOS 4b/4a. The genotypes of these genetic polymorphisms were determined using conventional PCR and PCR-RFLP methods. The PCR products were analysed using agarose gel electrophoresis. Statistical analysis was done using SPSS Version 22. Clinical characteristics, such as the diameter of ASD, mean arterial pressure (MAP), and mean pulmonary artery pressure (mPAP) differed significantly (p < 0.05). Based on the statistical analysis, ACE I/D, eNOS G894T, and eNOS 4b/4a do not contribute to the progression of PAH amongst ASD patients (p > 0.05). However, the L allele of the 5-HTTLPR gene polymorphism may have an affect on the development of PAH in ASD patients (p < 0.05).

Methylation Analysis of the BMPR2 Gene Promoter Region in Patients With Pulmonary Arterial Hypertension

INTRODUCTION

Pulmonary arterial hypertension is characterizated by obstruction of the pulmonary arteries. The gene mainly related to pathology is the bone morphogenetic protein receptor type II (BMPR2). The aim of this study was to analyze the methylation pattern of the BMPR2 promoter region in patients and controls.

METHODS

We used Methyl Primer Express(®) v.1.0 and MatInspector softwares to analyze this region. Genomic DNA obtained from the peripheral blood of patients and controls was modified with sodium bisulphite. Methylation was analyzed using methylation-specific PCR. DNA treated with CpG methyltransferase was used as a positive control for methylation and H1299 cell culture DNA was used as positive control for gene expression.

RESULTS

We identified a CpG island, which may have been methylated, in the BMPR2 promoter region, in addition to NIT-2 (global-acting regulatory protein), sex-determining region Y) and heat shock factor transcription factor binding sites. We found no evidence of methylation in patients and controls. No methylated CpG sites were identified in H1299 cells expressing the BMPR2 gene.

CONCLUSIONS

The BMPR2 promoter region is the most suitable for study because of the high number of transcription factor binding sites that could alter gene function. No evidence of methylation was detected in this region in patients and controls.

Relationship of genetic variation in the serotonin transporter gene (SLC6A4) and congenital and acquired cardiovascular diseases

Recent reports have suggested an association between variation in the serotonin transporter and primary pulmonary hypertension and myocardial infarction. We set out to determine whether these associations were present in a population of patients who underwent SLC6A4 genotyping and to explore whether genetic variation in the serotonin transporter might be also associated with other cardiovascular functional and structural abnormalities. Included were 3473 patients who were genotyped for the SLC6A4 5HTTLPR polymorphism and a subset for rs25531 (n=816) and STin2 (n=819). An association was observed between 5HTTLPR and primary pulmonary hypertension (p=0.0130), anomalies of the cerebrovascular system (p<0.0001), and other anomalies of great veins (p=0.0359). The combined 5HTTLPR and rs25531 genotype was associated with tachycardia (p=0.0123). There was an association of the STin2 genotype with abnormal electrocardiogram (ECG) (p=0.0366) and abnormal cardiac study (0.0311). Overall, these results represent a step toward the understanding of the impact of SLC6A4 variation on cardiovascular pathology.

Association between serotonin transporter (SERT) gene polymorphism and idiopathic pulmonary arterial hypertension: a meta-analysis and review of the literature

OBJECTIVE

Idiopathic pulmonary arterial hypertension (IPAH) is a rare and often fatal disease of unknown etiology. Serotonin transporter (SERT) protein, whose genes can have two allelic forms, namely long (L) and short (S), is suspected to be related to IPAH risk. Several studies have investigated the association between SERT's different allelic forms and IPAH but showed conflicting results. A meta-analysis of published studies was performed to allow a more reliable estimate of this association.

METHODS

Relevant databases were searched to identify eligible studies published from 2000 to 2013. Odds ratios (OR) and 95% confidence intervals (CI) were determined for the gene-disease association using fixed or random effects models.

RESULTS

A total of 6 studies with 451 IPAH subjects and 664 controls were included in this meta-analysis. A significant difference was found in the comparison between IPAH subjects and controls with LL vs. SS genotypes, and the pooled odds ratio (OR) with the fixed effects model was 1.446 (95% CI=1.036-2.018, p=0.030, I(2)=38.8%). However, no statistically significant differences were observed for LL vs. LS or LL vs. LS+SS. The pooled OR indicated no significant differences in IPAH risk between carriers of SERT L and S alleles (ORL VS. S=1.327, 95% CI=0.933-1.886, p=0.115).

CONCLUSION

This meta-analysis provides evidence suggesting an association between the SERT L/S polymorphism and IPAH. Individuals with the LL genotype have an obviously higher risk of developing IPAH than those with the SS genotype.