Gut microbiota and inflammatory factor characteristics in major depressive disorder patients with anorexia.

BACKGROUND: This study aimed to explore the gut microbiota and inflammatory factor characteristics in major depressive disorder (MDD) patients with anorexia and to analyze the correlation between gut microbiota and inflammatory factors, anorexia, and HAMD scores. METHODS: 46 MDD patients and 46 healthy controls (HC) were included in the study. The 46 MDD patients were divided into two groups according to whether they had anorexia:20 MDD without anorexia (MDA0 group) and 26 MDD with anorexia (MDA1 group). We used the Hamilton Depression Scale-24 (HAMD-24) to evaluate the depression status of all participants and 16 S ribosomal RNA (16 S rRNA)sequencing to evaluate the composition of the gut microbiota. Inflammatory factors in peripheral blood such as C-reactive protein (CRP) were detected using enzyme-linked immunosorbent assay (ELISA). Spearman's correlation analysis was used to evaluate the correlation between gut microbiota and inflammatory factors, HAMD scores, and anorexia. RESULTS: 1). CRP was significantly higher in the MDA0, MDA1, than HC. 2). An analysis of α-diversity shows: the Simpson and Pielou indices of the HC group are higher than the MDA1 group (P < 0.05). 3). The ß-diversity analysis shows differences in the composition of microbial communities between the MDA0, MDA1, and HC group. 4). A correlation analysis showed that Blautia positively correlated with anorexia, HAMD scores, and CRP level, whereas Faecalibacterium, Bacteroides, Roseburia, and Parabacteroides negatively correlated with anorexia, HAMD scores, and CRP level. 5). The receiver operating characteristic (ROC) curve was drawn using the differential bacterial genera between MDD patients with or without anorexia as biomarkers to identify whether MDD patients were accompanied with anorexia, and its area under curve (AUC) was 0.85. The ROC curve was drawn using the differential bacterial genera between MDD patients with anorexia and healthy controls as biomarkers to diagnose MDD patients with anorexia, with its AUC was 0.97. CONCLUSION: This study suggested that MDD patients with anorexia had a distinct gut microbiota compared to healthy individuals, with higher level of CRP. Blautia was more abundant in MDD patients with anorexia and positively correlated with CRP, HAMD scores, and anorexia. The gut microbiota might have influenced MDD and anorexia through the inflammatory factor CRP.

Facile fabrication of reinforced sub-micron fibrous media with hierarchical structure compounded thermally for effective air purification in application.

Air pollution has steadily worsened in recent years, and the coronavirus disease 2019 has been spreading since 2020. The electrospun fibrous filters present superior filtration performance, while the low mechanical property and yield of them limit their applications, which must be addressed urgently. Herein, polyacrylonitrile (PAN) sub-micron fibrous membrane with hierarchical structure was easily manufactured using free surface electrospinning in mass production for air purification. The "sandwich" structured fibrous filter was thermally bonded with bi-component nonwoven through traditional bonding procedures, due to melting and bonding of the cortex of bi-component fibers, in which the electrospun fibrous web as the mid layer with tortuous channels showed superior filtration performance for aerosol particles with diameter of 260 nm, which could effectively intercept different-sized particles suspended in the air. In addition, the impact of the processing parameters on the characteristics and filtration mechanisms of thermally bonded composite materials was thoroughly investigated. The results showed that composite material with "dendrites" and "axon" morphologies presented the best formability, outstanding peeling strength and breaking strength, and steady filtration performance, following an easy through-air bonding procedure, making it useful for post-processing in air purification. The reinforced composite filter, which is thermally bonded with sub-micron fibers with high yield and nonwoven, is save-energy and has a low operation cost, indicating its promising commercial possibilities.

Abnormal gut microbiota and bile acids in patients with first-episode major depressive disorder and correlation analysis.

AIM: Gut microbiota and its metabolite bile acids may play a significant role in the occurrence and development of major depressive disorder (MDD). Therefore, this study analyzes gut microbiota and bile acids, as well as their correlation in patients. METHODS: Thirty-one patients with MDD and 29 healthy controls (HCs) were enrolled in this study. We collected their both blood and feces. Plasma bile acid content was determined by liquid chromatography-mass spectrometry and gut microbiota was detected by 16SrRNA gene sequencing and subsequently analyzed. We also analyzed the correlation between different gut microbiota, bile acids, and Hamilton Depression (HAMD) score. RESULTS: The α-diversity analysis found that Simpson and Pielou evenness index was much higher in HCs than in the patients with MDD. The ß-diversity of the two groups were differences by nonmetric multidimensional scaling analysis. Linear discriminant analysis effect size analysis identified 16 different strains. Bile acids detection showed that 23-nordeoxycholic acid in patients with MDD was significantly higher than in HCs, whereas taurolithocholic acid (TLCA), glycolithocholic acid (GLCA), and lithocholic acid 3-sulfate were significantly lower. Spearman correlation analysis showed that Turicibacteraceae, Turicibacterales, and Turicibacter were positively related with TLCA, GLCA, glycodeoxycholic acid (GDCA), and taurodeoxycholic acid, and were negatively correlated with HAMD score. At the same time, TLCA, GLCA, and GDCA were negatively correlated with HAMD score. CONCLUSIONS: Gut microbiota and bile acids metabolism are disturbances in MDD, and there exists a correlation between gut microbiota and bile acids metabolism. Moreover, their interaction may be related to the pathophysiological mechanism of MDD.

Injuries in Left Corticospinal Tracts, Forceps Major, and Left Superior Longitudinal Fasciculus (Temporal) as the Quality Indicators for Major Depressive Disorder.

At present, the etiology and pathogenesis of major depressive disorder (MDD) are still not clear. Studies have found that the risk of first-degree relatives of MDD is 2-3 times that of the general population. Diffusion tensor imaging (DTI) has been previously used to explore the pathogenesis of MDD. The purpose of this study is to explore the etiology of MDD by DTI and further to explore the correlation between its clinical characteristics and the structural changes of white matter in the brain. The study included 27 first-episode, drug-naive patients with MDD, 16 first-degree relatives without MDD, and 28 healthy control subjects with no family history of MDD (HC). Results showed that the fractional anisotropy (FA) differences among the three groups were mainly in the left anterior thalamic radiation (LATR), right anterior thalamic radiation (RATR), left corticospinal tracts (LCST), forceps major (FMa), right inferior longitudinal fasciculus (RILF), and left superior longitudinal fasciculus (temporal) (LSLF(T)). Among the 6 sites, LCST, FMa, and LSLF(T) showed significant differences between MDD and First-degree relatives compared to HC. MDD patients had significant emotional symptoms, somatic symptoms, and cognitive impairment. FMa FA was significantly positively correlated with delayed memory score (r = 0.43, P = 0.031), and RILF FA was significantly negatively correlated with the FSS score (r = -0.42, P = 0.028). These results revealed that the white matter characteristics of MDD-susceptible patients were LCST, FMa, and LSLF(T) lesions, all of which may be quality indicators of MDD.

Aortic Valve Replacement with Bovine Pericardium in Patients with Aortic Valve Regurgitation.

This study aimed to analyze the early and mid-term outcomes of aortic valve replacement with bovine pericardium in the treatment of aortic valve regurgitation.From January 2015 to March 2018, 36 patients (19 men; mean ± standard deviation [SD] age, 46.70 ± 16.60 years) underwent aortic valve replacement with bovine pericardium. The bovine pericardium was intraoperatively measured and shaped using an Ozaki template, according to the shape and size of the individual patient's aortic valve leaflets. Additional procedures were performed, including ventricular septal defect repair in 5 cases, mitral valve reconstruction in 6 cases, tricuspid valve reconstruction in 6 cases, and coronary artery bypass grafting in 3 cases.There were no perioperative deaths. One elderly patient with postoperative respiratory failure recovered after symptomatic treatment. One patient with frequent ventricular tachycardia after intraoperative cardiac re-jump underwent intra-aortic balloon counterpulsation (IABP), and the IABP device was successfully removed on the second postoperative day. Within the first 6 months of follow-up, there were no death events, no reoperation events, and no additional thromboembolic events. Follow-up echocardiography was performed for 6 months, with average left ventricular ejection fraction of 62.01 ± 3.21%, mean transvalvular pressure gradient of 11.17 ± 4.90 mmHg, and mean aortic valve velocity of 1.60 ± 0.58 m/s. Compared with the preoperative transthoracic echocardiography findings, the results at the six-month follow-up were statistically significant (P < 0.05). Mild aortic valve regurgitation occurred in 2 patients (5.56%), whereas other patients had no or only minimal aortic valve regurgitation (n = 34, 94.44%). Moderate aortic valve regurgitation occurred in one patient at 9 months after the initial operation. This was found to be due to infective endocarditis, and a biological valve was finally implanted.Aortic valve replacement with bovine pericardium in the treatment of aortic valve regurgitation is feasible, and good early and mid-term results are achieved. Long-term results need to be followed up in the future.

Single Stage Hybrid Repair for DeBakey Type I Aortic Dissection in High Risk Patients.

OBJECTIVES: To evaluate the efficacy of the less invasive hybrid zone 0 (Z0) total aortic arch repair (HAR, ascending repair + complete debranching + thoracic endovascular aortic repair [TEVAR]) without deep hypothermic circulatory arrest in management of DeBakey type I aortic dissection (IAD). The adverse outcome was defined as a single composite endpoint comprising peri-operative mortality, permanent neurological deficit, and renal failure necessitating haemodialysis at discharge. METHODS: A retrospective review of prospectively collected data was conducted of 120 consecutive patients (mean EuroSCORE = 11.6%) with IAD undergoing HAR (urgent/emergency, n = 97, 80.8%) involving reconstruction of the ascending aorta (zone 0) and total arch exclusion with TEVAR during a 7.5 year period. Multivariable analysis of 27 potential pre-operative and intra-operative risk factors was performed to examine the early composite endpoint and short and long-term overall mortality. RESULTS: The total early (30 day or in hospital) mortality was 9.2% (n = 11). The incidence of the composite endpoint was 11.7% (n = 14). On multivariable analysis, malperfusion syndromes were predictors of the composite endpoint (odds ratio [OR], 4.789; 95% CI 1.362-16.896; p = .015), and previous cerebrovascular accident (OR, 13.74; 95% CI 2.330-81.039; p = .004) and myocardial ischaemia time (OR, 1.038; 95% CI 1.015-1.061; p = .001) predicted short and long-term overall mortality. The overall survival was 84.7% during a median follow up of 3.4 years. Freedom from late aortic adverse events was 93.1% at 5 years, including secondary aortic intervention and endoleak. The maximum diameters of the true lumen increased significantly in stented thoracic (14.4 ± 6.5 mm to 29.7 ± 5.3 mm, p < .001), lower thoracic (14.2 ± 6 mm to 21.6 ± 7.2 mm, p < .001) and abdominal (11.7 ± 4.8 mm to 17.4 ± 4.1 mm, p < .001) aorta. Complete thrombosis of the peri-stent false lumen was achieved in 88.2% of CT scans (82/93) performed a mean of 12 ± 17 months (median 5 months; 25-75% quartile, 2-12 months) post-operatively. CONCLUSIONS: IAD was treated safely and durably by Z0 HAR, and peri-operative mortality and morbidity were not substantially higher despite the older age and high risk of patients.

Functional connectivity between the thalamus and the primary somatosensory cortex in major depressive disorder: a resting-state fMRI study.

BACKGROUND: Studies have confirmed that the thalamus and the primary somatosensory cortex (SI) are associated with cognitive function. These two brain regions are closely related in structure and function. The interactions between SI and the thalamus are of crucial significance for the cognitive process. Patients with major depressive disorder (MDD) have significant cognitive impairment. Based on these observations, we used resting-state functional magnetic resonance imaging (rs-fMRI) to investigate whether there is an abnormality in the SI-thalamic functional connection in MDD. Furthermore, we explored the clinical symptoms related to this abnormality. METHODS: We included 31 patients with first-episode major depressive disorder and 28 age-, gender-, and education-matched healthy controls (HC). The SI-thalamic functional connectivity was compared between the MDD and HC groups. The correlation analyses were performed between areas with abnormal connectivity and clinical characteristics. RESULTS: Compared with healthy subjects, the MDD patients had enhanced functional connectivity between the thalamus and SI (p < 0.05, corrected). Brain areas with significantly different levels of connectivity had a negative correlation with the Assessment of Neuropsychological Status total score (r = - 0.383, p = 0.033), delayed memory score (r = - 0.376, p = 0.037) and two-digit continuous operation test score (r = - 0.369, p = 0.041) in MDD patients. CONCLUSIONS: These results demonstrate that SI-thalamic functional connectivity is abnormal and associated with the core clinical symptoms in MDD. The SI-thalamic functional connectivity functions as a neurobiological feature and potential biomarker for MDD.

Angiotensin II Induces an Increase in Matrix Metalloproteinase 2 Expression in Aortic Smooth Muscle Cells of Ascending Thoracic Aortic Aneurysms Through JNK, ERK1/2, and p38 MAPK Activation.

In this study, we hypothesized that angiotensin II (Ang II) induces matrix metalloproteinase 2 (MMP-2) upregulation in aneurysmal smooth muscle cells (ASMCs) derived from ascending thoracic aortic aneurysms (ATAAs). We compared MMP-2 protein levels in ascending aortic specimens using Western blot and plasma concentrations by enzyme-linked immunosorbent assay between ATAA (n = 40) and coronary heart disease patients (n = 40). Additionally, the protein level of angiotensinogen (AGT) in the ascending aorta and the plasma concentration of Ang II were detected by Western blot and radioimmunoassay, respectively, in ATAA and coronary heart disease patients. In ATAA patients, Ang II and MMP-2 plasma levels were significantly increased (P < 0.05). Additionally, AGT and MMP-2 protein levels in the aorta of ATAA patients were higher (P < 0.01). Enhanced AGT suggested that the amount of Ang II in aneurysmal aorta specimens may be also increased, which was confirmed by immunofluorescent staining for Ang II. Moreover, we investigated the effect of Ang II on MMP-2 upregulation by ASMCs and determined the Ang II receptors and intracellular signaling pathways that are involved. Our results showed that treatment with Ang II significantly increased the expression of MMP-2 through the Ang II type 1 receptor (AT1R) and activated the 3 major mitogen-activated protein kinases (MAPKs), JNK, ERK1/2, and p38 MAPK. In conclusion, these results indicate that Ang II can induce MMP-2 expression elevation through AT1R and MAPK pathways in ASMCs and suggest that there is therapeutic potential for angiotensin receptor blocker drugs and MAPK inhibitors in the prevention and treatment of ATAAs.

Characteristics of Oral-Gut Microbiota in Model Rats with CUMS-Induced Depression.

Purpose: The diversity and composition of the oral and gut microbiota of depressed rats were analyzed to explore the microbiological etiology of major depressive disorder (MDD). Methods: The depressed rat model was established by inducing chronic unpredictable mild stress (CUMS). After the establishment of the model, body weight measurements and behavioral tests were conducted. The diversity and composition of oral and gut microbiota were analyzed using 16SrRNA sequencing. Results: There were significant differences in the alpha and beta diversity of the oral microbiota of rats in the CUMS and control groups. The top three most abundant genera in the oral microbiota were Rothia, Psychrobacter, and Streptococcus. Linear discriminant analysis effect size (LEfSe) analysis showed that the abundance of Rothia decreased and that of Psychrotrophs increased in the CUMS group, and the differences were statistically significant. The top three most abundant genera in the gut microbiota were Lactobacillus, Ruminococcus and Oscillospira. LEfSe analysis showed that the abundance of Ruminococcus decreased in the CUMS group, and the difference was statistically significant. Spearman correlation analysis was performed to analyze the differential microbiota and depression-like behavior, which showed that differential microbiota significantly correlated with body weight, total distance traveled, average speed, and number of rearing. Spearman correlation analysis of oral and gut differential microbiota demonstrated a strong positive correlation between Facklamia in the oral cavity and Enterococcus, Streptococcus in the intestine (r=0.64-0.73, P<0.01); along with a strong negative correlation between Desulfovibrio in the oral cavity and Enterococcus, Turicibacter in the intestine(r=-0.51--0.72, P<0.05). Conclusion: Significant differences were observed in the diversity and composition of oral and gut microbiota between the CUMS depression model and control groups. Modulating the oral and gut microbiota may have positive effects on MDD.

Characteristics of gut microbiota and its correlation with hs-CRP and somatic symptoms in first-episode treatment-naive major depressive disorder.

OBJECTIVE: Most patients with major depressive disorder (MDD) have somatic symptoms, but little studies pay attention in the microbial-inflammatory mechanisms of these somatic symptoms. Our study aimed to investigate alterations in gut microbiota and its correlation with inflammatory marker levels and somatic symptoms in first-episode treatment-naive MDD. METHODS: Subjects contained 160 MDD patients and 101 healthy controls (HCs). MDD patients were divided into MDD with somatic symptoms group (MDDS) and MDD without somatic symptoms group (MDDN) based on Somatic Self-rating Scale (SSS). 16S ribosomal RNA sequencing were performed to analyze the composition of the fecal microbiota. The inflammatory factors were measured using enzyme linked immunosorbent assay (ELISA). Correlation among the altered gut microbiota, inflammatory factor and severity of clinical symptoms were analysized. RESULTS: Relative to HCs, MDD patients had higher levels of high-sensitivity C-reactive protein (hs-CRP) as well as disordered α-diversity and ß-diversity of gut microbiota. Linear discriminant effect size (LEfSe) analysis showed that MDD patients had higher proportions of Bifidobacterium, Blautia, Haemophilus and lower proportions of Bacteroides, Faecalibacterium, Roseburia, Dialister, Sutterella, Parabacteroides, Bordetella, and Phascolarctobacterium from the genus aspect. Furthermore, correlation analysis showed Bacteroides and Roseburia had negative correlations with the hs-CRP, HAMD-24, the total and factor scores of SSS in all participants. Further, compared with MDDN, the Pielous evenness was higher in MDDS. Random Forest (RF) analysis showed 20 most important genera discriminating MDD-S and MDDN, HCs. The ROC analysis showed that the AUC was 0.90 and 0.81 combining these genera respectively. CONCLUSION: Our study manifested MDD patients showed disordered gut microbiota and elevated hs-CRP levels, and altered gut microbiota was closely associated with hs-CRP, depressive symptoms, and somatic symptoms.

Immunoregulatory role of the gut microbiota in inflammatory depression.

Inflammatory depression is a treatment-resistant subtype of depression. A causal role of the gut microbiota as a source of low-grade inflammation remains unclear. Here, as part of an observational trial, we first analyze the gut microbiota composition in the stool, inflammatory factors and short-chain fatty acids (SCFAs) in plasma, and inflammatory and permeability markers in the intestinal mucosa of patients with inflammatory depression (ChiCTR1900025175). Gut microbiota of patients with inflammatory depression exhibits higher Bacteroides and lower Clostridium, with an increase in SCFA-producing species with abnormal butanoate metabolism. We then perform fecal microbiota transplantation (FMT) and probiotic supplementation in animal experiments to determine the causal role of the gut microbiota in inflammatory depression. After FMT, the gut microbiota of the inflammatory depression group shows increased peripheral and central inflammatory factors and intestinal mucosal permeability in recipient mice with depressive and anxiety-like behaviors. Clostridium butyricum administration normalizes the gut microbiota, decreases inflammatory factors, and displays antidepressant-like effects in a mouse model of inflammatory depression. These findings suggest that inflammatory processes derived from the gut microbiota can be involved in neuroinflammation of inflammatory depression.

Gut bacteria-driven homovanillic acid alleviates depression by modulating synaptic integrity.

The gut-brain axis is implicated in depression development, yet its underlying mechanism remains unclear. We observed depleted gut bacterial species, including Bifidobacterium longum and Roseburia intestinalis, and the neurotransmitter homovanillic acid (HVA) in individuals with depression and mouse depression models. Although R. intestinalis does not directly produce HVA, it enhances B. longum abundance, leading to HVA generation. This highlights a synergistic interaction among gut microbiota in regulating intestinal neurotransmitter production. Administering HVA, B. longum, or R. intestinalis to mouse models with chronic unpredictable mild stress (CUMS) and corticosterone (CORT)-induced depression significantly improved depressive symptoms. Mechanistically, HVA inhibited synaptic autophagic death by preventing excessive degradation of microtubule-associated protein 1 light chain 3 (LC3) and SQSTM1/p62 proteins, protecting hippocampal neurons' presynaptic membrane. These findings underscore the role of the gut microbial metabolism in modulating synaptic integrity and provide insights into potential novel treatment strategies for depression.

Surface plasmon modes in graphene wedge and groove waveguides.

Surface plasmon modes at terahertz-infrared waveband in subwavelength graphene wedge and groove waveguides are investigated, which can be categorized into perfect electric conductor and perfect magnetic conductor symmetric modes with different propagation characteristics. The electromagnetic near-fields are localized strongly in different regions for these two kinds of modes. Moreover, these modes can be interpreted by the folded graphene ribbon modes. The brim width of the waveguides and the Fermi energy of the graphene strongly influence the dispersion and propagation distances of the plasmon modes, which can be used for tuning the plasmon modes in graphene wedge and groove waveguides efficiently.

Association analysis of gut microbiota and efficacy of SSRIs antidepressants in patients with major depressive disorder.

BACKGROUND: Relevant studies have shown that gut microbiome plays an important role in the occurrence, development and treatment of major depressive disorder (MDD). Many studies have also shown that, selective serotonin reuptake inhibitors (SSRIs) antidepressants can improve the symptoms of depression by changing the distribution of gut microbiome, Here we investigated whether a distinct gut microbiome was associated with Major depressive disorder (MDD), and how it was modulated by SSRIs antidepressants. METHOD: In this study, we analyzed the gut microbiome composition of 62 patients with first-episode MDD and 41 matched healthy controls, before SSRIs antidepressants treatment, using 16S rRNA gene sequencing. MDD patients characterized as treatment-resistant (TR) or responders (R) to antidepressants by score reduction rate were ≥50 % after SSRIs antidepressants treatment for eight weeks. RESULTS: LDA effect size (LEfSe) analysis found that there were 50 different bacterial groups among the three groups, of which 19 genera were mainly at the genus level. The relative abundance of 12 genera increased in the HCs group, 5 genera in the R group increased in relative abundance, and 2 genera in the TR group increased in relative abundance. The correlation analysis of 19 bacterial genera and the score reduction rate showed that Blautia, Bifidobacterium and Coprococcus with higher relative abundance in the treatment effective group were related to the efficacy of SSRIs antidepressants. CONCLUSIONS: Patients with MDD have a distinct gut microbiome that changes after SSRIs antidepressants treatment. Dysbiosis could be a new therapeutic target and prognostic tool for the treatment of patients with MDD.

Gut microbiota composition in depressive disorder: a systematic review, meta-analysis, and meta-regression.

Studies investigating gut microbiota composition in depressive disorder have yielded mixed results. The aim of our study was to compare gut microbiome between people with depressive disorder and healthy controls. We did a meta-analysis and meta-regression of studies by searching PubMed, Web of Science, Embase, Scopus, Ovid, Cochrane Library, ProQuest, and PsycINFO for articles published from database inception to March 07, 2022. Search strategies were then re-run on 12 March 2023 for an update. We undertook meta-analyses whenever values of alpha diversity and Firmicutes, Bacteroidetes (relative abundance) were available in two or more studies. A random-effects model with restricted maximum-likelihood estimator was used to synthesize the effect size (assessed by standardized mean difference [SMD]) across studies. We identified 44 studies representing 2091 patients and 2792 controls. Our study found that there were no significant differences in patients with depressive disorder on alpha diversity indices, Firmicutes and Bacteroidetes compared with healthy controls. In subgroup analyses with regional variations(east/west) as a predictor, patients who were in the West had a lower Chao1 level (SMD -0.42[-0.74 to -0.10]). Subgroup meta-analysis showed Firmicutes level was decreased in patients with depressive disorder who were medication-free (SMD -1.54[-2.36 to -0.72]), but Bacteroidetes level was increased (SMD -0.90[0.07 to 1.72]). In the meta-regression analysis, six variables cannot explain the 100% heterogeneity of the studies assessing by Chao1, Shannon index, Firmicutes, and Bacteroidetes. Depleted levels of Butyricicoccus, Coprococcus, Faecalibacterium, Fusicatenibacter, Romboutsia, and enriched levels of Eggerthella, Enterococcus, Flavonifractor, Holdemania, Streptococcus were consistently shared in depressive disorder. This systematic review and meta-analysis found that psychotropic medication and dietary habit may influence microbiota. There is reliable evidence for differences in the phylogenetic relationship in depressive disorder compared with controls, however, method of measurement and method of patient classification (symptom vs diagnosis based) may affect findings. Depressive disorder is characterized by an increase of pro-inflammatory bacteria, while anti-inflammatory butyrate-producing genera are depleted.

Abnormal cortical-striatal-thalamic-cortical circuit centered on the thalamus in MDD patients with somatic symptoms: Evidence from the REST-meta-MDD project.

OBJECTIVE: Somatic symptoms are common comorbidities of major depressive disorder (MDD), and negatively impact the course and severity of the disease. In order to enrich the understanding of the pathological mechanism and clarify the neurobiological basis of somatic symptoms in depression, we attempted to explore the changes of brain structure and function in a large sample between depression with and without somatic symptoms. METHODS: Structure magnetic resonance imaging (MRI) data were collected from 342 patients with somatic symptoms (SD), 208 patients without somatic symptoms (NSD), and 510 healthy controls (HCs) based on the REST-meta-MDD project. We analyzed the whole brain VBM maps of the three groups, and combined with weight degree centrality (DC) index, we investigated whether the brain regions with gray matter volume (GMV) and gray matter density (GMD) abnormalities in MDD patients with somatic symptoms had corresponding brain functional abnormalities. RESULTS: Between depression with and without somatic symptoms, we found that there are extensive GMV and GMD differences involving cortical regions such as the temporal lobe, occipital lobe, and insula, as well as subcortical brain regions such as thalamus and striatum. The comparison results of weight DC signals of GMV and GMD abnormal clusters between the SD and NSD groups were basically consistent with the GMV and GMD abnormal clusters. CONCLUSION: The results indicate that the structure and function of cortical-striatal-thalamic-cortical (CSTC) circuit centered on the thalamus were abnormal in MDD patients with somatic symptoms. This may be the neurobiological basis of somatic symptoms in MDD.

A resting state fMRI study of major depressive disorder with and without anxiety.

BACKGROUND: The neurobiology of the Major depressive disorder (MDD) with anxiety is still unclear. The present study aimed to explore the brain correlates of MDD with and without anxiety in men and women during resting-state fMRI. METHODS: Two hundred and fifty-four patients with MDD (MDD with anxiety, N = 152) and MDD without anxiety, N = 102) and 228 healthy controls (HCs) participated in this study. We compared the fALFF(fractional amplitude of low-frequency fluctuations) and ReHo(regional homogeneity) of ACC(anterior cingulate cortex) and insula among these three groups. We also compared gender difference between MDD with anxiety and MDD without anxiety. RESULTS: We found that the fALFF values within the ACC and insula were significantly lower in MDD with anxiety compared to without anxiety and HCs. However, we did not find differences in ReHo values among the three groups. In women, we found significant differences in fALFF values between MDD with and without anxiety. These differences were not observed in men. CONCLUSIONS: It is possible that MDD with anxiety show less spontaneous BOLD-fMRI signal intensity within the ACC and insula compared to MDD without anxiety, especially in women. The fALFF within the ACC and insula can be a potential biomarker for severe MDD phenotype.

Characteristics and Mediating Effect of Gut Microbiota With Experience of Childhood Maltreatment in Major Depressive Disorder.

Gut microbiota and childhood maltreatment are closely related to depressive symptoms. This study aimed to analyze the characteristics of gut microbiota in major depressive disorder (MDD) patients with childhood maltreatment experience and explore the correlation between gut microbiota, childhood maltreatment, and depressive symptoms. A total of 37 healthy controls (HCs) and 53 patients with MDD were enrolled, including 18 MDD patients without childhood maltreatment experience and 35 MDD patients with childhood maltreatment experience. The Hamilton's Depression Scale (HAMD-24) and Childhood Trauma Questionnaire-Short Form (CTQ-SF) were used to evaluate their depressive symptoms and childhood maltreatment experience, respectively. The composition of gut microbiota was evaluated using 16S rRNA sequencing. Spearman's correlation analysis was used to evaluate the correlation between different gut microbiota, depressive symptoms and childhood maltreatment. The mediation analysis was used to evaluate the mediating effect of gut microbiota. In the α-diversity analysis, we found that the Simpson index and Pielou's Evenness index differed significantly between MDD patients without childhood maltreatment experience and HCs. In the ß-diversity analysis, principal coordinate analysis (PCoA) showed significant differences between MDD patients without childhood maltreatment experience, MDD patients with childhood maltreatment experience and HCs. Twenty-seven different bacteria were identified through Linear discriminant analysis effect size (LEfSe) analysis at different levels of classification. The analysis of the correlation showed that Blautia, Bifidobacterium, Bacteroides, Roseburia, and Phascolarctobacterium were significantly correlated with HAMD and CTQ-SF scores. The mediation analysis showed that childhood maltreatment had a significant direct effect on the patients' depressive symptoms, and Blautia, Bifidobacterium, Roseburia had a significant mediating effect. The findings of this study suggested that MDD patients with childhood maltreatment experience had different gut microbiota, which might have a mediating effect on the influence of childhood maltreatment on depressive symptoms.

Altered Cingulum Functioning in Major Depressive Disorder Patient With Suicide Attempts: A Resting-State Functional Magnetic Resonance Imaging Study.

Background: Major depressive disorder (MDD) with suicide attempts (SA) poses a significant public health issue. This study aims to identify neurobiological markers for MDD with SA on resting-state brain functional magnetic resonance imaging (rs-fMRI). Methods: Fifty-one unmedicated adult MDD participants, 27 with SA on the Beck Scale for Suicidal Ideation and 24 without SA, underwent rs-fMRI scanning. A group of 30 healthy controls (HC) matched for age, gender, and education-level with MDD were chosen. A whole brain analysis of regional homogeneity (ReHo) was performed on subjects to identify regions where brain activity was associated with SA. Multiple comparison analysis was performed for ReHo. Pearson's correlation analysis was performed between HAMD-SA scores and ReHo. The statistical significance level was set at p < 0.05. Results: We examined whether there were significant differences among the three groups in whole brain ReHo during resting state. Subjects with SA showed significant increase of ReHo in the right Cingulum Post in comparison with those without SA. Subjects with SA showed significant decrease of ReHo in the right Cingulate Gyrus/Precuneus in comparison with HC. The mean ReHo from the significant brain region was associated with HAMD-SA (item 3 of the HAMD) scores (r = 0.349, P = 0.012) but was not associated with HAMD-24 scores. Conclusion: These results indicate that SA is associated with altered resting-state brain activity. The pattern of elevated activity in the cingulum functioning may be related to SA. Identifying cingulum activity associated with SA may help to elucidate its pathogenesis and etiology.

EEG microstates as markers of major depressive disorder and predictors of response to SSRIs therapy.

BACKGROUND: Major depressive disorder (MDD) is associated with abnormal neural activities and brain connectivity. EEG microstate is a voltage topology map that reflects transient activations of the brain network. A limited number of studies on EEG microstate in MDD have focused on differences between patients and healthy controls. However, EEG microstate changes in MDD patients before and after drug treatment have not been evaluated. We assessed EEG microstate characteristics and evaluated changes in brain network dynamics in MDD patients before and after drug treatment. Moreover, we evaluated the neuro-electrophysiological mechanisms of antidepressant therapies. METHODS: 64-channel resting EEG was obtained from 101 patients with first-episode untreated depression (0 week) and 45 healthy controls (HC) from January to December 2020. MDD patients were treated with selective serotonin reuptake inhibitors (SSRI). EEG data for 51 MDD patients who had completed an 8-week follow-up was collected. After pre-processing, EEG data from different groups were subjected to microstate analysis, and the atomize and agglomerate hierarchical clustering (AAHC) was into 4 microstates. Next, EEG signals from each patient were fitted using templates of 4 microstates. Finally, microstate indices were collected and analyzed. RESULTS: Global clustering generated 4 microstates (A, B, C, D) in all subjects, which explained 65-84% of the global variance. Compared to HC, the duration of microstate D reduced while those of microstates A and B increased in MDD patients. After the 8-week treatment period, the duration and coverage of microstate D increased, the frequency of microstate A and transition probability of microstate D to A reduced, while transition probability of microstate B to D and D to B increased in MDD patients. There were no differences in microstate features between HC and MDD at 8 weeks. In patients with first-episode untreated depression, lower average durations of microstate D, relatively higher frequencies of microstate C and lower transition probabilities of microstate D to B correlated with better effects after 8 weeks. The higher occurrence and proportion of microstate C at 8 weeks was positively correlated with the HAMD score and reduction rate. The same observation was reached for the transition probability of microstate A to C. However, the transition probability of microstate D to B showed a negative correlation with the HAMD score at 8 weeks. CONCLUSION: Microstate D is a potential electrophysiological trait of MDD and can predict treatment outcomes of SSRIs. Therefore, EEG microstate analysis may not only be an objective method for evaluating treatment outcomes of depression, but is also a potential new approach for exploring the neuro-electrophysiological mechanisms of antidepressant therapy. Public title: Multidimensional diagnosis, individualized treatment and management techniques based on clinic-pathological characteristics of depressive disorder; Registration number: ChiCTR1900026600; Date of registration: 2019-10-15; URL: http://www.chictr.org.cn/index.aspx.