Association of indoleamine 2,3 dioxygenase, brain derived neurotrophic factor and cellular senescence in type 2 diabetes mellitus with depression: a clinical approach

BACKGROUND AND AIM

Type 2 diabetes mellitus (T2DM) and depression are often linked. Several studies have reported the role of molecular markers either in diabetes or depression. The present study aimed at molecular level profiling of Indoleamine-2,3-dioxygenase (IDO), brain-derived neurotrophic factor (BDNF) and cellular senescence in patients with type 2 diabetes with and without depression compared to individuals with healthy controls.

METHODS

A total of 120 individuals diagnosed with T2DM were enlisted for the study, with a subset of participants with and without exhibiting depression. The gene expression analysis was done using quantitative real-time PCR.

RESULTS

Indoleamine 2,3 dioxygenase (p < 0.001) and senescence genes (p < 0.001) were significantly upregulated, while brain derived neurotrophic factor (p < 0.01) was significantly downregulated in T2DM patients comorbid with and without depression when compared to healthy controls.

CONCLUSION

Indoleamine 2,3 dioxygenase, Brain derived neurotrophic factor and cellular senescence may play a role in the progression of the disease. The aforementioned discoveries offer significant contributions to our understanding of the molecular mechanisms that underlie T2DM with depression, potentially aiding in the advancement of prediction and diagnostic methods for this particular ailment.

Ginsenoside Rk3 Regulates Tryptophan Metabolism along the Brain-Gut Axis by Targeting Tryptophan Hydroxylase and Remodeling the Intestinal Microenvironment to Alleviate Depressive-Like Behavior in Mice

Depression is a neuropsychiatric disease that significantly impacts the physical and mental health of >300 million people worldwide and places a major burden on society. Ginsenosides are the main active ingredient in ginseng and have been proven to have various pharmacological effects on the nervous system. Herein, we investigated the antidepressant effect of ginsenoside Rk3 and its underlying mechanism in a murine model of depression. Rk3 significantly improved depression-like behavior in mice, ameliorated the disturbance of the hypothalamus-pituitary-adrenal axis, and alleviated neuronal damage in the hippocampus and prefrontal cortex of mice. Additionally, Rk3 improved the abnormal metabolism of tryptophan in brain tissue by targeting tryptophan hydroxylase, thereby reducing neuronal apoptosis and synaptic structural damage in the mouse hippocampus and prefrontal cortex. Furthermore, Rk3 reshaped the composition of the gut microbiota of mice and regulated intestinal tryptophan metabolism, which alleviated intestinal barrier damage. Thus, this study provides valuable insights into the role of Rk3 in the tryptophan metabolic cycle along the brain-gut axis, suggesting that Rk3 may have the potential for treating depression.

Differentially expressed genes of esophageal tissue in male acute and chronic sleep deprivation mice

Gastroesophageal reflux disease (GERD) is associated with sleep disturbances. However, mechanisms underlying these interactions remain unclear. Male acute and chronic sleep deprivation (SD) mice were used for this study. Mice in the chronic SD group exhibited anxiety- and depression-like behaviors. We further performed high-throughput genome sequencing and bioinformatics analysis to screen for featured differentially expressed genes (DEGs) in the esophageal tissue. The acute SD group, comprised 25 DEGs including 14 downregulated and 11 upregulated genes. Compared with the acute SD group, more DEGs were present in the chronic SD group, with a total of 169 DEGs, including 88 downregulated and 81 upregulated genes. Some DEGs that were closely related to GERD and associated esophageal diseases were significantly different in the chronic SD group. Quantitative real-time polymerase chain reaction verified the downregulation of Krt4, Krt13, Krt15 and Calml3 and upregulation of Baxl1 and Per3. Notably, these DEGs are involved in biological processes, which might be the pathways of the neuroregulatory mechanisms of DEGs expression.

FGF2 gene's antisense protein, NUDT6, plays a depressogenic role by promoting inflammation and suppressing neurogenesis without altering FGF2 signalling

Fibroblast growth factor-2 (FGF2) is involved in the regulation of affective behaviour and shows antidepressant effects through the Akt and extracellular signal regulated kinase (ERK) 1/2 pathways. Nudix hydrolase 6 (NUDT6) protein is encoded from FGF2 gene's antisense strand and its role in the regulation of affective behaviour is unknown. Here, we overexpressed NUDT6 in the hippocampus and investigated its behavioural effects and the underlying molecular mechanisms affecting the behaviour. We showed that increasing hippocampal NUDT6 results in depression-like behaviour in rats without changing FGF2 levels or activating its downstream effectors, Akt and ERK1/2. Instead, NUDT6 acted by inducing inflammatory signalling, specifically by increasing S100 calcium binding protein A9 (S100A9) levels, activating nuclear factor-kappa B-p65 (NF-κB-p65), and elevating microglia numbers along with a reduction in neurogenesis. Our results suggest that NUDT6 could play a role in major depression by inducing a proinflammatory state. This is the first report of an antisense protein acting through a different mechanism of action than regulation of its sense protein. The opposite effects of NUDT6 and FGF2 on depression-like behaviour may serve as a mechanism to fine-tune affective behaviour. Our findings open up new venues for studying the differential regulation and functional interactions of sense and antisense proteins in neural function and behaviour, as well as in neuropsychiatric disorders. KEY POINTS: Hippocampal overexpression of nudix hydrolase 6 (NUDT6), the antisense protein of fibroblast growth factor-2 (FGF2), increases depression-like behaviour in rats. Hippocampal NUDT6 overexpression triggers a neuroinflammatory cascade by increasing S100 calcium binding proteinA9 (S100A9) expression and nuclear NF-κB-p65 translocation in neurons, in addition to microglial recruitment and activation. Hippocampal NUDT6 overexpression suppresses neurogenesis. NUDT6 exerts its actions without altering the levels or downstream signalling pathways of FGF2.

Heritable Composite Phenotypes Defined by Combinations of Conduct Problem, Depression, and Temperament Features: Contributions to risk for Alcohol Problems

The genetic architectures underlying symptoms of conduct problems and depression have largely been examined separately and without incorporating temperament, despite evidence for their genetic overlap. We examined how symptoms and temperament dimensions were transmitted together in families to identify highly heritable composite phenotypes, and how these composite phenotypes predicted alcohol outcomes in young adulthood. Participants (N = 486) were drawn from the third generation of families oversampled for alcohol use disorder in the first generation. Conduct problems, depression, and temperament were reported at 11-19 years old and alcohol outcomes at 18-26 years old. Using principal components of heritability analysis, we found seven highly heritable composite phenotypes, five of which predicted alcohol outcomes: three characterized by co-occurring conduct problems and depression and two by conduct problems. Novel composite phenotypes that were characterized by both conduct problems and depression showed different types of symptoms, temperament features, and genetic underpinnings. Children manifesting differing composite phenotypes might benefit from distinct treatments based on their unique etiologies.

Epigenetic mechanisms in depression: Implications for pathogenesis and treatment

The risk of depression is influenced by both genetic and environmental factors. It has been suggested that epigenetic mechanisms may mediate the risk of depression following exposure to adverse life events. Epigenetics encompasses stable alterations in gene expression that are controlled through transcriptional, post-transcriptional, translational, or post-translational processes, including DNA modifications, chromatin remodeling, histone modifications, RNA modifications, and non-coding RNA (ncRNA) regulation, without any changes in the DNA sequence. In this review, we explore recent research advancements in the realm of epigenetics concerning depression. Furthermore, we evaluate the potential of epigenetic changes as diagnostic and therapeutic biomarkers for depression.

The causal relationship between depression and obstructive sleep apnea: A bidirectional Mendelian randomization study

OBJECTIVE

Numerous studies have reported the close association of depression with obstructive sleep apnea (OSA). However, the causal nature and direction remain unclear. This study aimed to identify the genetic causal relationship between depression and OSA using Mendelian randomization (MR).

METHODS

Based on publicly available genome-wide association studies data of depression and OSA, we conducted a bidirectional two-sample MR study. The inverse-variance weighted (IVW) was used as the main analysis method. Moreover, multivariable MR was performed to further explore the underlying genetic causality of OSA and depression after adjusting for several potential mediators.

RESULTS

The univariable MR analysis revealed a significant causality of depression on the susceptibility of OSA (ORivw = 1.29, 95%CI:1.11,1.50; p < 0.001). This relationship was evidenced by the phenotypes for broad depression (ORivw = 3.30, 95%CI: 1.73, 6.29; p < 0.001), probable major depression (ORivw = 18.79, 95%CI: 5.69, 61.99; p < 0.001), and ICD-10 major depression (ORivw = 23.67, 95%CI: 4.13, 135.74; p < 0.001). In the reverse direction, no significant causal effect of OSA on depression was found. After adjusting for smoking, alcohol use, obesity, type 2 diabetes, insomnia, age, gender, and codeine, most of these results suggested that depression remained significantly and positively associated with OSA.

CONCLUSION

These findings may contribute to the understanding of the etiology of depression and OSA and also suggest the clinical significance of controlling depression for the prevention of OSA.

Appraising the causal association among depression, anxiety and intracranial aneurysms: Evidence from genetic studies

BACKGROUND

The risk of intracranial aneurysms (IAs) is increased in individuals with depression and anxiety. This indicates that depression and anxiety may contribute to the development of physical disorders. Herein, to investigate the association between genetic variants related to depression and anxiety and the risk of IA, two-sample Mendelian randomization was performed.

METHODS

The genome-wide association study (GWAS) comprised genome-wide genotype data of 2248 clinically well-characterized patients with anxiety and 7992 ethnically matched controls from four European countries. Sex-specific summary-level outcome data were obtained from the GWAS of IA, including 23 cohorts with a total of 10,754 cases and 306,882 controls of European and East Asian ancestry. To improve validity, five varying Mendelian randomization techniques were used in the analysis, namely Mendelian randomization-Egger, weighted median, inverse variance weighted, simple mode, and weighted mode.

RESULTS

The inverse variance weighted results indicated the causal effect of depression on IA (P = 0.03, OR = 1.32 [95 % CI, 1.03-1.70]) and unruptured IA (UIA) (P = 0.02, OR = 1.68 [95 % CI, 1.08-2.61]). However, the causal relationship between depression and subarachnoid hemorrhage (SAH) was not found (P = 0.16). We identified 43 anxiety-associated single-nucleotide polymorphisms as genetic instruments and found no causal relationship between anxiety and IA, UIA, and SAH.

LIMITATIONS

Potential pleiotropy, possible weak instruments, and low statistical power limited our findings.

CONCLUSION

Our MR study suggested a possible causal effect of depression on the increased risk of UIAs. Future research is required to investigate whether rational intervention in depression treatment can help to decrease the societal burden of IAs.

Association of oral behaviours and psychological factors with selected genotypes in pain-related TMD

OBJECTIVES

To investigate frequency of single nucleotide polymorphisms (SNPs) in pain-related temporomandibular disorders (TMDp) and to determine whether specific SNPs, psychological, psychosomatic and behavioural characteristics are predictive for pain existence and intensity (low pain intensity (LPI)/high pain intensity (HPI)).

METHODS

Genomic DNA was extracted from buccal mucosa swabs (85 TMDp;85 controls) for evaluating frequency of selected SNPs: catechol-O-methyltransferase (rs4680, rs4818), opiorphin (rs1387964), alpha subunit of voltage-gated sodium channel Nav1.1 (rs6432860) and voltage-gated sodium channel Nav1.9 (rs33985936). Participants completed questionnaires on somatosensory amplification, anxiety and depression symptoms and oral behaviours (OB).

RESULTS

Sleep-related OB frequency was higher in TMDp patients compared to controls (p = 0.008). Compared to LPI, HPI patients had higher depression (p = 0.020) and anxiety scores (p = 0.017). TMDp group showed higher frequency of CC genotype (rs1387964) than controls (12.9% vs. 3.5%, p = 0.025). Following adjustments for age, sex and sleep-related OB, the significance of the recessive model (CC vs. TC + TT) between TMDp patients and controls was retained (OR = 5.783; 95%CI: 1.454-23.004). Frequency of GG genotype (rs4680 and rs4818) was higher in HPI compared to LPI patients (40% vs. 11.4%, p = 0.006; 24% vs. 3%; p = 0.012, respectively). The difference remained significant after adjusting for age, sex, depression, anxiety and sleep-related OB (rs4680: OR = 3.621; 95%CI: 1.580-8.297; rs4818: OR = 4.919, 95%CI: 1.641-14.746).

CONCLUSION

This study has demonstrated that rs1387964 CC genotype was associated with TMDp while rs4680 GG and rs4818 GG genotypes contributed to HPI.

[Mechanism of Jiaotai Pills in treatment of depression by UHPLC-TOF-MS combined with network pharmacology and experimental validation]

This study aims to analyze the constituents of Jiaotai Pills migrating to the blood in normal rats by UHPLC-TOF-MS technique and reveal the underlying mechanism of Jiaotai Pills in the treatment of depression by network pharmacology and animal experiments. UHPLC-TOF-MS technique was used to detect the constituents of Jiaotai Pills in the blood of rats after intragastric administration. The intersection target of the constituents and depression was screened by DisGeNET and SwissTargetPrediction database, and the protein-protein interaction(PPI) network was constructed. Key targets were imported into the DAVID platform for Gene Ontology(GO) analysis and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway annotation. Combined with constituents, targets, and pathways, the "constituent-target-pathway" network was constructed by Cytoscape 3.9.1 software, through which the key targets and pathways of Jiaotai Pills against depression were predicted. The depression model of chronic unpredictable mild stress(CUMS) was established on rats. After that, behavioral experiments were conducted. The expression of inflammatory factors in serum and the neurotransmitters in the brain were detected by ELISA, and the expression of key targets in the hippocampus was detected by Western blot. The results showed that a total of 17 constituents of Jiaotai Pills were identified in the blood, including 10 alkaloids. There were 124 intersection targets between constituents of Jiaotai Pills and depression disorder. A total of 52 core targets were screened according to PPI results, including NLRP3 and caspase-1, etc. KEGG enrichment analysis mainly involved 15 typical pathways such as NOD-like receptor pathway. The results of animal experiments showed that Jiaotai Pills significantly improved the depression-like behavior of CUMS depressive model on rats, decreased the levels of IL-1β, TNF-α and IL-6 in serum, and increased the expression of neurotransmitters such as 5-hydroxytryptamine(5-HT), dopamine(DA), and norepinephrine(NE) in the brain. Besides, Jiaotai Pills also down-regulated the expression of NLRP3 and caspase-1 proteins in the hippocampus and inhibited the NLRP3-mediated NOD-like receptor signaling pathway. In conclusion, Jiaotai Pills may play a role in the treatment of depression by inhibiting the NLRP3 inflammasome and the NOD-like receptor pathway mediated by NLRP3.

Offspring's own serotonin transporter genotype, independently from the maternal one, increases anxiety- and depression-like behavior and alters neuroplasticity markers in rats

INTRODUCTION

Developmental changes due to early life variations in the serotonin system affect stress-related behavior and neuroplasticity in adulthood. These outcomes can be caused both by offspring's own and maternal serotonergic genotype. We aimed to dissociate the contribution of the own genotype from the influences of mother genotype.

METHODS

Sixty-six male homozygous (5-HTT-/-) and heterozygous (5-HTT+/-) serotonin transporter knockout and wild-type rats from constant 5-HTT genotype mothers crossed with varying 5-HTT genotype fathers were subjected to tests assessing anxiety- and depression-like behaviors. Additionally, we measured plasma corticosterone levels and mRNA levels of BDNF, GABA system and HPA-axis components in the prelimbic and infralimbic cortex. Finally, we assessed the effect of paternal 5-HTT genotype on these measurements in 5-HTT+/- offspring receiving their knockout allele from their mother or father.

RESULTS

5-HTT-/- offspring exhibited increased anxiety- and depression-like behavior in the elevated plus maze and sucrose preference test. Furthermore, Bdnf isoform VI expression was reduced in the prelimbic cortex. Bdnf isoform IV and GABA related gene expression was also altered but did not survive false discovery rate (FDR) correction. Finally, 5-HTT+/- offspring from 5-HTT-/- fathers displayed higher levels of anxiety- and depression-like behavior and changes in GABA, BDNF and HPA-axis related gene expression not surviving FDR correction.

LIMITATIONS

Only male offspring was tested.

CONCLUSIONS

Offspring's own 5-HTT genotype influences stress-related behaviors and Bdnf isoform VI expression, independently of maternal 5-HTT genotype. Paternal 5-HTT genotype separately influenced these outcomes. These findings advance our understanding of the 5-HTT genotype dependent susceptibility to stress-related disorders.

Polygenic risk for depression predicting temperament trajectories over 15 years - A general population study

BACKGROUND

A great number of case-control and population-based studies have shown that depression patients differ from healthy controls in their temperament traits. We investigated whether polygenic risk for depression predicts trajectories of temperament traits from early adulthood to middle age.

METHODS

Participants came from the population-based Young Finns Study (n = 2212). The calculation for Polygenic risk for depression (PRS) was based on the most recent genome-wide association study. Temperament traits of Harm Avoidance, Novelty Seeking, Reward Dependence, and Persistence were assessed with the Temperament and Character Inventory in 1997, 2001, 2007, and 2012 (participants being 24-50-year-olds). As covariates, we used depressive symptoms as assessed by a modified version of the Beck Depression Inventory, psychosocial family environment from parent-filled questionnaires, and socioeconomic factors from adulthood.

RESULTS

High PRS predicted higher Persistence from early adulthood to middle age (p = 0.003) when controlling for depressive symptoms, psychosocial family environment, and socioeconomic factors. PRS did not predict trajectories of Novelty Seeking (p = 0.063-0.416 in different models) or Reward Dependence (p = 0.531-0.736). The results remained unaffected when participants with diagnosed affective disorders were excluded. Additionally, we found an interaction between PRS and depressive symptoms when predicting the Harm Avoidance subscale Anticipatory Worry, indicating that the association of Anticipatory Worry with depressive symptoms is stronger in individuals with higher (vs. lower) PRS.

LIMITATIONS

There was some attrition due to the long follow-up.

CONCLUSIONS

High polygenic risk for major depression may predict differences in temperament trajectories among those who have not developed any severe affective disorders.

Association between social isolation and depression: Evidence from longitudinal and Mendelian randomization analyses

BACKGROUND

Increasing evidence shows that social isolation and depression are likely to interact with each other, yet the direction and causality of the association are not clear. This study aims to examine the possible reciprocity in the relationship between social isolation and depression.

METHODS

This study fitted a cross-lagged panel model (CLPM) by using data from the English Longitudinal Study of Aging (ELSA, 2014-2019, n = 6787) to examine the temporal relationship between social isolation and depressive symptoms in older adults. We then conducted two-sample bidirectional Mendelian randomization (MR) analyses by using independent genetic variants associated with multiple social isolation phenotypes (n = 448,858-487,647) and with depression (n = 215,644-2,113,907) as genetic instruments from genome-wide association studies to assess the causality between social isolation and onset of depression.

RESULTS

The CLPM in the ELSA cohort showed a significant and positive lagged effect of social isolation on depressive symptoms (β = 0.037, P < .001). The reverse cross-lagged path from depressive symptoms to social isolation was also statistically significant (β = 0.039, P < .001). In two-sample bidirectional MR, the genetically predicted loneliness and social isolation combined phenotype (LNL-ISO) was positively associated with occurrence of depression (OR = 1.88, 95 % CI: 1.41-2.50, P < .001), vice versa (OR = 1.16, 95 % CI:1.13-1.20, P < .001).

LIMITATIONS

The self-report nature of the assessments and missing data are study limitations.

CONCLUSIONS

These findings suggest a bidirectional relationship between social isolation and depression. It is important to develop interventions that highlight the reciprocal consequences of improving either mental health or social connection in older adults.

Blood RNA-sequencing analysis in acrylamide-induced neurotoxicity and depressive symptoms in rats

Acrylamide (ACR) is a by-product of the Maillard reaction, which occurs when food reacts at high temperatures. Occupational exposure is a risk factor for chronic ACR toxicity. ACR may cause neurotoxicity and depressive symptoms with high concentration in the blood; however, the underlying mechanism remains unknown. We showed the rats developed neurotoxic symptoms after being fed with ACR for 28 days, such as reduced activity and hind limb muscle weakness. We investigated whether ACR exposure causes gene expression differences by blood RNA sequencing and analyzed the differential expression of depressive symptoms-associated genes. The result indicated that IFN-γ the key regulator of neurotoxicity and depressive symptoms was induced by ACR. ACR induced the ubiquitin-mediated proteolysis pathway and JAK/STAT pathways gene expression. ACR upregulated the expression of IFN-γ, inducing neuroinflammation and neurotoxicity. ACR also upregulated the expression of JAK2, STAT1, PI3K, AKT, IκBα, UBE2D4, NF-κB, TNF-α, and iNOS in rat brain tissues and Neuro-2a cells. Thus, IFN-γ induction by ACR may induce depressive symptoms, and the ubiquitin-mediated proteolysis pathway and JAK/STAT pathways may involve in ACR neurotoxicity and depressive symptoms.

Circulating mitochondrial long non-coding 7S RNA in primary health care patients with depression/anxiety

BACKGROUND

The significant role of long non-coding 7S RNA in controlling mitochondrial transcription highlights its importance in mitochondrial function. Considering the suggested connection between mitochondrial dysfunction and the onset of mental disorders, this study aimed to explore the potential involvement of 7S RNA in the context of depression/anxiety.

RESULTS

A total of 181 patients in primary health care (age 20-64 years) with depression/anxiety and 59 healthy controls were included in the study. 7S RNA was measured using quantitative real-time PCR in plasma samples collected before (baseline) and after 8 weeks of treatment (mindfulness or cognitive-based behavioral therapy). Upon adjustment for age and sex, the baseline plasma levels of 7S RNA were significantly higher in patients than in healthy controls (p < 0.001). Notably, post-treatment, there was a significant reduction in 7S RNA levels (p = 0.03). These changes in 7S RNA were related to the treatment response, as indicated by HADS-D (Hospital Anxiety and Depression Scale) scores (ß = -0.04, p = 0.04), even after accounting for baseline scores and other cofounders.

CONCLUSION

The findings of this study indicate an association between plasma 7S RNA levels and depression/anxiety, as well as treatment response. While further confirmatory analyses are necessary, plasma 7S RNA holds promise as a potential predictive biomarker for both depression/anxiety and the treatment response within these disorders.

Exploring the causal relationships and mediating factors between depression, anxiety, panic, and atrial fibrillation: A multivariable Mendelian randomization study

BACKGROUND

Atrial fibrillation is a significant cardiovascular disease, and the increased risk of its occurrence may be influenced by mental disorders. Currently, the causal relationship between them remains controversial. Our aim is to ascertain the relationship between atrial fibrillation and mental disorders including depression, anxiety, and panic, as well as the risk factors mediating this relationship, through the judgment of genetic susceptibility.

METHODS

We utilized the summarized statistics from nine large-scale genome-wide association studies (in European populations), including depression (PGC, N = 807,553), anxiety (FinnGen, N = 429,209), panic (PGC, N = 230,878), diabetes (UK Biobank, N = 655,666), smoking (IEU, 607,291), hypertension (UK biobank, N = 463,010), obstructive sleep apnea (IEU, N = 476,853), obesity (UK biobank, N = 463,010), and AF (IEU, N = 1,030,836). By applying bidirectional two-sample Mendelian randomization and multivariable Mendelian randomization to depression, anxiety, panic, and AF, we analyzed their causal relationships and the independent influence of specific risk factors. Furthermore, a two-step MR approach was used to assess the mediating effects of diabetes, smoking, hypertension, obstructive sleep apnea, and obesity.

RESULTS

Results from the Two-Sample Mendelian Randomization Inverse Variance Weighted Random Effects Model show: the occurrence of genetically predicted depression is related to an increased risk of atrial fibrillation (AF) (OR: 1.073; [95 % CI: 1.005-1.146] P < 0.05), and panic is more significantly associated than depression (OR: 1.017; [95 % CI: 1.008-1.027] P < 0.001), while anxiety has no causal relationship with the occurrence of AF (OR: 1.023; [95 % CI: 0.960-1.092], P > 0.05), and AF is not significantly related to the occurrence of depression, anxiety, or panic (P > 0.05). After correcting for the other two risk factors using multivariable Mendelian randomization, depression remains significantly related to the occurrence of AF (β: 0.075; 95 % CI: [0.006, 0.144], P < 0.05), while panic and anxiety are not related to the occurrence of AF. Among them, the risk factors for AF occurrence, hypertension and obesity, are mediators between depression and AF, with mediation proportions of 74.9 % and 14.3 %, respectively. The mediating effects of diabetes, smoking, and obstructive sleep apnea were found to be not statistically significant. The above results are robust after sensitivity analysis.

CONCLUSION

Our results identified that the genetic susceptibility to depression is an independent risk factor for the occurrence of AF, and that hypertension and obesity can mediate this process. Panic also poses some risk to the onset of AF. This demonstrates that controlling hypertension and obesity for emotional management is of great importance in preventing the occurrence of AF.

Single-cell RNA-sequencing of cellular heterogeneity and pathogenic mechanisms in paraquat-induced Parkinson's disease with depression

Parkinson's disease (PD) is among the most prevalent neurodegenerative diseases, and approximately one third of patients with PD are estimated to have depression. Paraquat (PQ) exposure is an important environmental risk factor for PD. In this study, we established a mouse model of PQ-induced PD with depression to comprehensively investigate cellular heterogeneity and the mechanisms underlying the progression of depression in the context of PD. We utilized single-cell RNA-seq (scRNA-seq) to acquire the transcriptomic atlas of individual cells from model mice and characterize the gene expression profiles in each differentially expressed cell type. We identified a specific glutamatergic neuron cluster responsible for the development of heterogeneous depression-associated changes and established a comprehensive gene expression atlas. Furthermore, functional enrichment and cell trajectory analyses revealed that the mechanisms underlying the progression of PD with depression were associated with specific glutamatergic neurons. Together, our findings provide a valuable resource for deciphering the cellular heterogeneity of PD with depression. The suggested connection between intrinsic transcriptional states of neurons and the progression of depression can provide insight into potential biomarkers and specific targets for anti-depression treatment in patients with PD. SYNOPSIS: Our results obtained using model mice confirm the core effects of PQ exposure on glutamatergic neurons and their potential role in the development of PD with depression.

Biomarkers of Depression among Adolescent Girls: BDNF and Epigenetics

Alterations in brain-derived neurotrophic factor (BDNF) expression have been suggested to mediate the influence of environmental factors on the emergence of depression through epigenetic modifications. However, research on this subject in the developmental population is lacking and the pathophysiology of adolescent depression remains unclear. We aimed to investigate the alterations in BDNF expression and global DNA methylation in depression among adolescent girls. Thirty female inpatients with the initial diagnosis of depression were assessed before and after the period of antidepressant treatment and compared with thirty age-matched healthy controls. The assessment involved BDNF and proBDNF serum levels, the BDNF gene exon IV promoter methylation, and global DNA methylation. The methylation level in the BDNF gene exon IV promoter was significantly lower in the studied group compared with the control and correlated negatively with the severity of depression. The test distinguished the studied group from the controls with a sensitivity of 37% and specificity of 90%. The differences were no longer present after the period of antidepressant treatment. No differences in the global DNA methylation, BDNF, and proBDNF levels were found. We concluded that decreased methylation in the BDNF exon IV promoter could be considered as a biomarker of a depression state among adolescent girls.

Cohort profile: BioMD-Y (biopsychosocial factors of major depression in youth) - a biobank study on the molecular genetics and environmental factors of depression in children and adolescents in Munich

PURPOSE

BioMD-Y is a comprehensive biobank study of children and adolescents with major depression (MD) and their healthy peers in Germany, collecting a host of both biological and psychosocial information from the participants and their parents with the aim of exploring genetic and environmental risk and protective factors for MD in children and adolescents.

PARTICIPANTS

Children and adolescents aged 8-18 years are recruited to either the clinical case group (MD, diagnosis of MD disorder) or the typically developing control group (absence of any psychiatric condition).

FINDINGS TO DATE

To date, four publications on both genetic and environmental risk and resilience factors (including FKBP5, glucocorticoid receptor activation, polygenic risk scores, psychosocial and sociodemographic risk and resilience factors) have been published based on the BioMD-Y sample.

FUTURE PLANS

Data collection is currently scheduled to continue into 2026. Research questions will be further addressed using available measures.

Differential effect of chronic mild stress on anxiety and depressive-like behaviors in three strains of male and female laboratory mice

Major depressive disorder is the most common psychiatric disorder worldwide. To understand mechanisms and search for new approaches to treating depression, animal models are crucial. Chronic mild stress (CMS) is the most used animal model of depression. Although CMS is considered a robust model of depression, conflicting results have been reported for emotion-related behaviors, which the intrinsic characteristics of each rodent strain could explain. To further shed light on the impact of genetic background on the relevant parameters commonly addressed in depression, we examined the effect of 4-weeks CMS on anxiety and depression-related behaviors and body weight gain in three strain mice (BALB/c, C57BL/6, and CD1) of both sexes. CMS reduced body weight gain in C57BL/6NCrl and CD1 male mice. C57BL/6 animals exhibited a more pronounced anxious-like behavior than CD1 and BALB/c mice in the light-dark box (LDB) and the elevated plus maze (EPM) tests, whereas BALB/c animals exhibited the more robust depressive-like phenotype in the splash test (ST), tail suspension test (TST) and forced-swimming test (FST). Under CMS, exposure did not affect anxiety-related behaviors in any strain but induced depression-like behaviors strain-dependently. CMS C57BL/6 and CD1 mice of both sexes showed depression-like behaviors, and CMS BALB/c male mice exhibited reduced depressive behaviors in the FST. These results suggest a differential effect of stress, with the C57BL/6 strain being more vulnerable to stress than the CD1 and BALB/c strain mice. Furthermore, our findings emphasize the need for researchers to consider mouse strains and behavioral tests in their CMS experimental designs.

Evaluation of the Observational Associations and Shared Genetics Between Glaucoma With Depression and Anxiety

Purpose

Glaucoma, a leading cause of blindness worldwide, is suspected to exhibit a notable association with psychological disturbances. This study aimed to investigate epidemiological associations and explore shared genetic architecture between glaucoma and mental traits, including depression and anxiety.

Methods

Multivariable logistic regression and Cox proportional hazards regression models were employed to investigate longitudinal associations based on UK Biobank. A stepwise approach was used to explore the shared genetic architecture. First, linkage disequilibrium score regression inferred global genetic correlations. Second, MiXeR analysis quantified the number of shared causal variants. Third, specific shared loci were detected through conditional/conjunctional false discovery rate (condFDR/conjFDR) analysis and characterized for biological insights. Finally, two-sample Mendelian randomization (MR) was conducted to investigate bidirectional causal associations.

Results

Glaucoma was significantly associated with elevated risks of hospitalized depression (hazard ratio [HR] = 1.54; 95% confidence interval [CI], 1.01-2.34) and anxiety (HR = 2.61; 95% CI, 1.70-4.01) compared to healthy controls. Despite the absence of global genetic correlations, MiXeR analysis revealed 300 variants shared between glaucoma and depression, and 500 variants shared between glaucoma and anxiety. Subsequent condFDR/conjFDR analysis discovered 906 single-nucleotide polymorphisms (SNPs) jointly associated with glaucoma and depression and two associated with glaucoma and anxiety. The MR analysis did not support robust causal associations but indicated the existence of pleiotropic genetic variants influencing both glaucoma and depression.

Conclusions

Our study enhances the existing epidemiological evidence and underscores the polygenic overlap between glaucoma and mental traits. This observation suggests a correlation shaped by pleiotropic genetic variants rather than being indicative of direct causal relationships.

Genetics, epigenetics, and neurobiology of childhood-onset depression: an umbrella review

Depression is a serious and persistent psychiatric disorder that commonly first manifests during childhood. Depression that starts in childhood is increasing in frequency, likely due both to evolutionary trends and to increased recognition of the disorder. In this umbrella review, we systematically searched the extant literature for genetic, epigenetic, and neurobiological factors that contribute to a childhood onset of depression. We searched PubMed, EMBASE, OVID/PsychInfo, and Google Scholar with the following inclusion criteria: (1) systematic review or meta-analysis from a peer-reviewed journal; (2) inclusion of a measure assessing early age of onset of depression; and (3) assessment of neurobiological, genetic, environmental, and epigenetic predictors of early onset depression. Findings from 89 systematic reviews of moderate to high quality suggest that childhood-onset depressive disorders have neurobiological, genetic, environmental, and epigenetic roots consistent with a diathesis-stress theory of depression. This review identified key putative markers that may be targeted for personalized clinical decision-making and provide important insights concerning candidate mechanisms that might underpin the early onset of depression.

Correlations of Expression Levels of Lung Cancer Marker Gene Eno2 and Genes of Carcinogenesis and Apoptosis in the Hypothalamus of Mice with Depression-Like Behavior

We experimentally demonstrated that chronic social stress during the development of a depression-like state enhances lung metastasis and modifies the expression of many carcinogenesis- and apoptosis-related genes in the hypothalamus of mice, including genes involved in lung cancer pathogenesis in humans. Analysis of the expression of genes encoding the major clinical markers of lung cancer in the hypothalamus of mice with depression-like behavior revealed increased expression of the Eno2 gene encoding neuron-specific enolase, a blood marker of lung cancer progression in humans. It was shown that the expression of this gene in the hypothalamus correlated with the expression of many carcinogenesis- and apoptosis-related genes. The discovered phenomenon may have a fundamental significance and requires further studies.