Catecholamine pathway polymorphisms and antidepressant response

The Predictive Role of ADRA2A rs1800544 and HTR3B rs3758987 Polymorphisms in Motion Sickness Susceptibility

Motion sickness is a common central nervous system response, the primary sign of which is vomiting. Its susceptibility varies between individuals. To find predictive factors, we investigated the association of ADRA2A rs1800544 and HTR3B rs3758987 with motion sickness susceptibility and examined their mRNA changes during actual voyages. A total of 315 healthy college students were enrolled for SNP genotyping by the PCR-RFLP method. Blood samples were collected from another 42 subjects during two separate voyages to detect their mRNA expression changes at three time points. The frequency of the rs1800544 GG genotype in the susceptibility group was significantly higher (52.26%), and allele G increased the risk of motion sickness (OR = 1.585, 95% CI = 1.136-2.208). In the logistic regression model, the rs3758987 CC+TC genotype and rs1800544 GG genotype increased the risk of motion sickness-induced vomiting (OR = 2.105, 95% CI = 1.112-3.984; OR = 1.992, 95% CI = 1.114-3.571). The ADRA2A mRNA baseline was lower in the GG carriers and the HTR3B mRNA baseline was lower in the TC/CC carriers before sailing, then increased significantly within 24 h and then decreased after a long-term voyage. People carrying the rs1800544 GG genotype seem more susceptible to motion sickness. In combination with the incidence of vomiting during the actual-voyage experiments, our results indicate the involvement of rs1800544 and rs3758987 in motion sickness-induced vomiting.

Relationship between genetic variation in the α2A-adrenergic receptor and the cardiovascular effects of dexmedetomidine in the Chinese Han population

There are differences in individual cardiovascular responses to the administration of dexmedetomidine, a highly selective α_2A-adrenergic receptor (ADRA2A) agonist. The aim of this study was to investigate ADRA2A gene polymorphisms in the Chinese Han population and their association with the cardiovascular response to intravenous dexmedetomidine infusion. Sixty elective surgery patients of Chinese Han nationality were administered 1 µg/kg dexmedetomidine intravenously over 10 min as a premedication. ADRA2A C-1291G and A1780G polymorphism status was determined in these patients, and their relationships to changes in blood pressure and heart rate after dexmedetomidine administration were analyzed. There were neither significant differences in systolic or diastolic blood pressure changes in individuals with different A1780G and C-1291G genotypes after dexmedetomidine administration, nor in heart rates among the different A1780G genotypes. However, there were significant differences in changes in heart rates in patients with different C-1291G genotypes. There were no significant differences in the sedative effects of dexmedetomidine among different A1780G and C-1291G genotypes. Logistic regression revealed that the C-1291G polymorphism was associated with differential decreases in heart rate after intravenous infusion of dexmedetomidine. These findings indicate that the ADRA2A C-1291G polymorphism can affect heart rate changes in patients after intravenous infusion of dexmedetomidine.

Systems Approach to Identify Common Genes and Pathways Associated with Response to Selective Serotonin Reuptake Inhibitors and Major Depression Risk

Despite numerous studies on major depressive disorder (MDD) susceptibility, the precise underlying molecular mechanism has not been elucidated which restricts the development of etiology-based disease-modifying drug. Major depressive disorder treatment is still symptomatic and is the leading cause of (~30%) failure of the current antidepressant therapy. Here we comprehended the probable genes and pathways commonly associated with antidepressant response and MDD. A systematic review was conducted, and candidate genes/pathways associated with antidepressant response and MDD were identified using an integrative genetics approach. Initially, single nucleotide polymorphisms (SNPs)/genes found to be significantly associated with antidepressant response were systematically reviewed and retrieved from the candidate studies and genome-wide association studies (GWAS). Also, significant variations concerning MDD susceptibility were extracted from GWAS only. We found 245 (Set A) and 800 (Set B) significantly associated genes with antidepressant response and MDD, respectively. Further, gene set enrichment analysis revealed the top five co-occurring molecular pathways (p ≤ 0.05) among the two sets of genes: Cushing syndrome, Axon guidance, cAMP signaling pathway, Insulin secretion, and Glutamatergic synapse, wherein all show a very close relation to synaptic plasticity. Integrative analyses of candidate gene and genome-wide association studies would enable us to investigate the putative targets for the development of disease etiology-based antidepressant that might be more promising than current ones.