A novel NR3C2 polymorphism and the increased thyroid-stimulating hormone concentration are associated with venlafaxine treatment outcome in Chinese Han MDD patients

Genetic Landscape of Major Depressive Disorder: Assessment of Potential Diagnostic and Antidepressant Response Markers

BACKGROUND

The clinical heterogeneity in major depressive disorder (MDD), variable treatment response, and conflicting findings limit the ability of genomics toward the discovery of evidence-based diagnosis and treatment regimen. This study attempts to curate all genetic association findings to evaluate potential variants for clinical translation.

METHODS

We systematically reviewed all candidates and genome-wide association studies for both MDD susceptibility and antidepressant response, independently, using MEDLINE, particularly to identify replicated findings. These variants were evaluated for functional consequences using different in silico tools and further estimated their diagnostic predictability by calculating positive predictive values.

RESULTS

A total of 217 significantly associated studies comprising 1200 variants across 545 genes and 128 studies including 921 variants across 412 genes were included with MDD susceptibility and antidepressant response, respectively. Although the majority of associations were confirmed by a single study, we identified 31 and 18 replicated variants (in at least 2 studies) for MDD and antidepressant response. Functional annotation of these 31 variants predicted 20% coding variants as deleterious/damaging and 80.6% variants with regulatory effect. Similarly, the response-related 18 variants revealed 25% coding variant as damaging and 88.2% with substantial regulatory potential. Finally, we could calculate the diagnostic predictability of 19 and 5 variants whose positive predictive values ranges from 0.49 to 0.66 for MDD and 0.36 to 0.66 for response.

CONCLUSIONS

The replicated variants presented in our data are promising for disease diagnosis and improved response outcomes. Although these quantitative assessment measures are solely directive of available observational evidence, robust homogenous validation studies are required to strengthen these variants for molecular diagnostic application.

Depression and Autoimmune Hypothyroidism—Their Relationship and the Effects of Treating Psychiatric and Thyroid Disorders on Changes in Clinical and Biochemical Parameters Including BDNF and Other Cytokines—A Systematic Review

Various autoimmune diseases, including autoimmune hypothyroidism (AHT), are associated with a higher risk of developing mood disorders throughout life. Depression is accompanied by the changes in the levels of inflammatory and trophic factors, including interleukins (IL-1beta, IL-2, IL-6), interferon alpha (IFN-alpha), tumor necrosis factor alpha (TNF-alpha), C-reactive protein (CRP), and brain derived neurotrophic factor (BDNF). Disclosure of the relationship between the coexistence of depression and AHT indicates that the pathomechanism of depression may be related to the changes in the immune system, it is also possible that both conditions may be caused by the same immune processes. The above hypothesis is indirectly supported by the observations that the treatment with both antidepressants and levothyroxine leads to a decrease in the levels of proinflammatory cytokines with an increase in BDNF concentrations, simultaneously correlating with an improvement in the clinical parameters. However, so far there are no long-term studies determining the causal relationship between depression, thyroid autoantibodies, and cytokine profile, which could bring us closer to understanding the interrelationships between them and facilitate the use of an adequate pharmacotherapy, not necessarily psychiatric. We consider the above issues to be insufficiently investigated but of great importance. This article is an overview of the available literature as well as an introduction to our research project.

Subclinical thyroid dysfunction and major depressive disorder

PURPOSE

This review attempts to investigate the link between subclinical thyroid dysfunction (SCH) and major depressive disorder (MDD). It has been speculated that SCH may be related to MDD through an autoimmune mechanism.

METHODS

A comprehensive literature search was conducted in the PubMed database for relevant research and review articles.

RESULTS

There appears to be an association between an autoimmune mechanism, possibly involving the thyroid gland, and depressive disorders, but the available evidence is so far inconclusive.

CONCLUSION

Lifetime prevalence of depression is significantly higher in patients with SCH, a finding reflecting a possible effect of SCH in lowering the threshold for the emergence of MDD. The relationship between SCH and MDD is, however, not clear, with large and well-designed studies investigating possible links between reference-range thyroid hormone levels and MDD having as yet found no relation between the two.

Molecular Mechanisms Associated with Antidepressant Treatment on Major Depression

Major depressive disorder (MDD) is a complex and multifactorial psychiatric disorder that causes serious health, social, and economic concerns worldwide. The main treatment of the symptoms is through antidepressant (AD) drugs. However, not all patients respond properly to these drugs. Omic sciences are widely used to analyze not only biomarkers for the AD response but also their molecular mechanism. In this review, we aimed to focus on omics data to better understand the molecular mechanisms involving AD effects on MDD. We consistently found, from preclinical to clinical data, that glutamatergic transmission, immune/inflammatory processes, energy metabolism, oxidative stress, and lipid metabolism were associated with traditional and potential new ADs. Despite efforts of studies investigating biomarkers of response to ADs, which could contribute to personalized treatment, there is no biomarker panel available for clinical application. From clinical genomic studies, we found that the main findings contribute to the development of pharmacogenomic tests for AD efficacy for each patient. Several studies pointed at DRD2, PXDNL, CACNA1E, and CACNA2D1 genes as potential targets for MDD treatment and the efficacy and rapid-antidepressant effect of ketamine. Finally, more in-depth studies of the molecular targets pointed here are needed to determine the clinical relevance and provide further evidence for precision MDD treatment.

Association between SLC17A7 gene polymorphisms and venlafaxine for major depressive disorder in a Chinese Han population: a prospective pharmacogenetic case-control study

Objective:

Venlafaxine is a common antidepressant and its therapeutic effect varies among people with different genetic backgrounds. The aim of this study was to investigate whether single nucleotide polymorphisms (SNPs) in the SLC17A7 gene are associated with the treatment outcome of venlafaxine in a Chinese Han population with major depressive disorder.

Methods:

This prospective pharmacogenetic case-control study that involved genotyping of four SNPs of SLC17A7 was conducted on 175 major depressive disorder patients of Chinese Han origin, aged 18 to 65 years, participated in the study from April 2005 to September 2006. Comparisons of allele and genotype frequencies of all SNPs were performed between the responder/remission group and the nonresponder/nonremission group. This study was approved by the Institutional Ethics Committee of Sichuan University (approval No. 20151112-265).

Results:

The allele and genotype frequencies of the four candidate SNPs in SCL17A7 showed no significant difference between responders and nonresponders. Meanwhile, no significant difference was detected in the four investigated SLC17A7 SNPs between patients who did and did not exhibit remission. Although one of the investigated SLC17A7 variants (rs1578944) demonstrated a significant association ( P =0.022) with a response to venlafaxine after 6 weeks of treatment in the survival analysis, the association was unclear after a Bonferroni multiple comparisons test was conducted.

Conclusion:

No significant association exists between the four candidate SNPs (rs1043558, rs1320301, rs1578944, and rs74174284) in SLC17A7 and venlafaxine treatment in the Chinese Han population.

Association of Polygenetic Risk Scores Related to Cell Differentiation and Inflammation with Thyroid Cancer Risk and Genetic Interaction with Dietary Intake

The incidence of thyroid cancer continues to increase steadily, and this increasing incidence cannot be attributed solely to the overdiagnosis of microcarcinoma or technical advancements in detection methods and may also depend on environmental and genetic factors. However, the impacts and interactions of genetic and environmental factors remain controversial, and they may differ in Eastern and Western countries. The study's purpose was to identify single nucleotide polymorphisms of genes related to cell differentiation and inflammation to influence thyroid cancer incidence and determine interactions with lifestyles in a large city hospital-based cohort. Genetic variants were selected by genome-wide association study with thyroid cancer participants (case; n = 495) and controls without cancers (n = 56,439). SNPs having gene-gene interactions were selected by generalized multifactor dimensionality reduction. Polygenic risk scores (PRSs) were generated by summing the number of selected SNP risk alleles. PRSs of the best model included 6 SNPs, that is, DIRC3_rs6759952, GAP43_rs13059137, NRG1_rs7834206, PROM1_rs72616195, LRP1B_rs1369535, and LOC100507065_rs11175834. Participants with a high-PRS had a higher thyroid cancer risk by 3.9-fold than those with a low-PRS. The following variables were related to an increased thyroid cancer risk; female (OR = 4.21), high white blood cell count (OR = 4.03), and high energy (OR = 7.00), low alcohol (OR = 4.11), and high seaweed (OR = 4.02) intakes. These variables also interacted with PRS to influence thyroid cancer risk. Meat/noodle diet patterns interacted with PRSs to increase thyroid cancer risk (p = 0.0023). In conclusion, women with a high-PRS associated with cell differentiation and inflammation were at an elevated thyroid cancer risk. Daily energy, seaweeds, and alcohol intake interacted with PRS for thyroid cancer risk. These results could be applied to personalized nutrition plans to reduce the risk of thyroid cancer.

No Association Between SLC6A4 Gene Polymorphisms With Treatment Remission to Venlafaxine in Han Chinese Depressive Patients

OBJECTIVE

Major depressive disorder (MDD) is a heterogeneous psychiatric disorder and considered to be one of the most common mental diseases worldwide. The antidepressant venlafaxine, as a serotonin noradrenaline reuptake inhibitor, is applied to MDD relief. Solute carrier family 6 member 4 (SLC6A4) has been reported to promote the reuptake of serotonin and to be closely correlated to depression. The present study examined whether rs6354 and rs1487971 in SLC6A4 are associated with remission after venlafaxine treatment in MDD patients.

METHODS

This study consisted of 195 Han Chinese patients with MDD, who accepted a 6-week treatment with venlafaxine. Two SLC6A4 single-nucleotide polymorphisms (SNPs) were selected from database of SNP and genotyped by matrix-assisted laser desorption/ionization time of flight mass spectrometer in MassARRAY Analyzer 4 platforms. The 17-item Hamilton Depression Scale was used to access the severity of major depression. Allele and genotype frequencies between patients in remission and nonremission were calculated with online software SHEsis.

RESULTS

No significant differences in allele or genotype frequencies were observed in rs6354 and rs1487971. There were no significant associations between 2 SNPs and venlafaxine treatment outcome.

CONCLUSIONS

It suggested that rs6354 or rs1487971 within SLC6A4 appears not to be involved in the venlafaxine treatment outcome in Han Chinese patients with MDD.