Up-regulation of serotonin receptor 2B mRNA and protein in the peri-infarcted area of aged rats and stroke patients

DDCM: A Computational Strategy for Drug Repositioning Based on Support-Vector Regression Algorithm

Computational drug-repositioning technology is an effective tool for speeding up drug development. As biological data resources continue to grow, it becomes more important to find effective methods to identify potential therapeutic drugs for diseases. The effective use of valuable data has become a more rational and efficient approach to drug repositioning. The disease-drug correlation method (DDCM) proposed in this study is a novel approach that integrates data from multiple sources and different levels to predict potential treatments for diseases, utilizing support-vector regression (SVR). The DDCM approach resulted in potential therapeutic drugs for neoplasms and cardiovascular diseases by constructing a correlation hybrid matrix containing the respective similarities of drugs and diseases, implementing the SVR algorithm to predict the correlation scores, and undergoing a randomized perturbation and stepwise screening pipeline. Some potential therapeutic drugs were predicted by this approach. The potential therapeutic ability of these drugs has been well-validated in terms of the literature, function, drug target, and survival-essential genes. The method's feasibility was confirmed by comparing the predicted results with the classical method and conducting a co-drug analysis of the sub-branch. Our method challenges the conventional approach to studying disease-drug correlations and presents a fresh perspective for understanding the pathogenesis of diseases.

Dapoxetine prevents neuronal damage and improves functional outcomes in a model of ischemic stroke through the modulation of inflammation and oxidative stress

Stroke is a medical emergency that is associated with substantial mortality and functional disability in adults. The most popular class of antidepressants, selective serotonin reuptake inhibitors SSRIs, have recently been shown in studies to have positive effects on post-stroke motor and cognitive function. Thus, we hypothesized that dapoxetine (DAP), a short-acting SSRI, would be effective against cerebral ischemia/reperfusion injury. Adult male Wister rats (200-250 g) were subjected to a sham operation or bilateral common carotid artery occlusion (BCCAO) for 30 min followed by 24 h of reperfusion to induce global cerebral ischemia/reperfusion (I/R) injury. Rats were treated with vehicle or DAP (30 or 60 mg/kg, i.p.) 1 h before BCCAO. The neurobehavioral performance of rats was assessed. The infarct volume, histopathological changes, oxidative stress parameters, and apoptotic and inflammatory mediators were determined in the brain tissues of euthanized rats. Our results confirmed that DAP significantly ameliorated cerebral I/R-induced neurobehavioral deficits, reduced cerebral infarct volume, and histopathological damage. Moreover, DAP pretreatment reduced lipid peroxidation, caspase-3, and inflammatory mediators (TNF-α and iNOS) compared to I/R-injured rats. Thus, DAP pretreatment potentially improves neurological function, and cerebral damage in cerebral ischemic rats may be partly related to the reduction in the inflammatory response, preservation of oxidative balance, and suppression of cell apoptosis in brain tissues.

Molecular mechanisms underlying major depressive disorder and post-stroke affective disorders

Two of the most common and incapacitating mental health disorders around the world are major depressive disorder (MDD) and post-stroke depression (PSD). MDD is thought to result from abnormal connectivity between the monoaminergic, glutamatergic, GABAergic, and/or cholinergic pathways. Additional factors include the roles of hormonal, immune, ageing, as well as the influence of cellular, molecular, and epigenetics in the development of mood disorders. This complexity of factors has been anticipated by the Swiss psychiatrists Paul Kielholz and Jules Angst who introduced a multimodal treatment of MDD. Depression is the predominant mood disorder, impacting around one-third of individuals who have experienced a stroke. MDD and PSD share common underlying biological mechanisms related to the disruption of monoaminergic pathways. The major contributor to PSD is the stroke lesion location, which can involve the disruption of the serotoninergic, dopaminergic, glutamatergic, GABAergic, or cholinergic pathways. Additionally, various other disorders such as mania, bipolar disorder, anxiety disorder, and apathy might occur post-stroke, although their prevalence is considerably lower. However, there are differences in the onset of MDD among mood disorders. Some mood disorders develop gradually and can persist for a lifetime, potentially culminating in suicide. In contrast, PSD has a rapid onset because of the severe disruption of neural pathways essential for mood behavior caused by the lesion. However, PSD might also spontaneously resolve several months after a stroke, though it is associated with higher mortality. This review also provides a brief overview of the treatments currently available in medical practice.

Alterations of learning and memory are accompanied by alterations in the expression of 5-HT receptors, glucocorticoid receptor and brain-derived neurotrophic factor in different brain regions of an animal model of depression generated by neonatally male treatment with clomipramine in male rats

Depressive illness has been associated with impaired cognitive processes accompanied by reduced neurotrophin levels, especially brain-derived neurotrophic factor (BDNF), and dysfunctions in the hypothalamic-pituitary-adrenal (HPA) axis. In addition, depression is characterized by a decreased functioning of the serotonergic system due to changes in the activity or expression of its receptors including, most significantly, 5-HT1A, 5-HT2A, and 5-HT3 in brain regions that regulate mood, emotions, and memory, such as the prefrontal cortex, hippocampus, and amygdala. In this regard, rats treated with clomipramine (CMI) in the neonatal stage show depression-like behaviors that persist into adulthood; hence, this constitutes an adequate model of depression for exploring various molecular aspects associated with the etiology of this disorder. This, study, then, was designed to analyze the long-term effects of early postnatal exposure to CMI on the expression of 5-HT1A, 5-HT2A, and 5-HT3 receptors, as well as BDNF and GR in the following brain regions: PFC, amygdala, hippocampus, and hypothalamus, which could be related to alterations in memory and learning, as evaluated using the novel object recognition (NOR) and Morris water maze (MWM). Expression of the 5-HT1A, 5-HT2A, and 5-HT3 receptors, BDNF, and the glucocorticoid receptor (GR) was assessed by RT-qPCR in the four aforementioned brain regions, all of which play important roles in the control of memory and mood. Findings show that neonatal treatment with CMI causes alterations in memory and learning, as indicated by alterations in the results of the MWM and NOR tests. Expression of the 5-HT1A receptor increased in the hippocampus, amygdala, and hypothalamus, but decreased in the PFC, while the 5-HT2A and BDNF receptors decreased their expression in the PFC, amygdala, and hippocampus. There was no change in the expression of the 5-HT3 receptor. In addition, expression of GR in the hippocampus and PFC was low, but increased in the hypothalamus. Taken together, these data show that neonatal CMI treatment produces permanent molecular changes in brain regions related to learning and memory that could contribute to explaining the behavioral alterations observed in this model.

Targeting serotonin receptor 2B inhibits TGFβ induced differentiation of human vascular smooth muscle cells

Vascular Smooth Muscle Cells (VSMCs) are known to be the key drivers of intimal thickening which contribute to early progression of atherosclerosis. VSMCs are the major producers of extracellular matrix within the vessel wall and in response to atherogenic stimuli they could modify the type of matrix proteins produced. Serotonin receptor 2B (5-HT_2B receptor/HTR2B) has been implicated in several chronic fibrotic and vascular diseases. Although studies have successfully demonstrated the efficacy of HTR2B blockade in attenuating fibrotic disease, the role of 5-HT2B receptor in TGFβ mediated VSMC differentiation remain largely unknown. In the present study, we investigated the potential of targeting the 5-HT2B receptor to prevent TGFβ induced VSMCs differentiation. Our results showed that 5-HT2B receptors are expressed in human atherosclerotic lesion and HTR2B expression positively correlated to the VSMCs markers. We show that AM1125, a selective 5-HT2B receptor inhibitor, significantly inhibits TGFβ1 induced production of collagen and CTGF. The investigation of underlying mechanisms indicated that 5-HT2B receptor antagonism blocks phospho-Smad2 mediated downstream signaling of TGFβ1 in vascular smooth muscle cells. Collectively, the HTR2B/TGF-β1/Phospho-Smad2 pathway plays a critical role in the regulation of VSMCs differentiation. Our findings might serve 5-HT2B receptor as a therapeutic target to limit TGF-β1 induced VSMC differentiation.

Targeting inflammation: a potential approach for the treatment of depression

Major depressive disorder (MDD) or Depression is one of the serious neuropsychiatric disorders affecting over 280 million people worldwide. It is 4th important cause of disability, poor quality of life, and economic burden. Women are more affected with the depression as compared to men and severe depression can lead to suicide. Most of the antidepressants predominantly work through the modulation on the availability of monoaminergic neurotransmitter (NTs) levels in the synapse. Current antidepressants have limited efficacy and tolerability. Moreover, treatment resistant depression (TRD) is one of the main causes for failure of standard marketed antidepressants. Recently, inflammation has also emerged as a crucial factor in pathological progression of depression. Proinflammatory cytokine levels are increased in depressive patients. Antidepressant treatment may attenuate depression via modulation of pathways of inflammation, transformation in structure of brain, and synaptic plasticity. Hence, targeting inflammation may be emerged as an effective approach for the treatment of depression. The present review article will focus on the preclinical and clinical studies that targets inflammation. In addition, it also concentrates on the therapeutic approaches' that targets depression via influence on the inflammatory signaling pathways. Graphical abstract demonstrate the role of various factors in the progression and neuroinflammation, oxidative stress. It also exhibits the association of neuroinflammation, oxidative stress with depression.

Microglia Involves in the Immune Inflammatory Response of Poststroke Depression: A Review of Evidence

Poststroke depression (PSD) does not exist before and occurs after the stroke. PSD can appear shortly after the onset of stroke or be observed in the weeks and months after the acute or subacute phase of stroke. The pathogenesis of PSD is unclear, resulting in poor treatment effects. With research advancement, immunoactive cells in the central nervous system, particularly microglia, play a role in the occurrence and development of PSD. Microglia affects the homeostasis of the central nervous system through various factors, leading to the occurrence of depression. The research progress of microglia in PSD has been summarized to review the evidence regarding the pathogenesis and treatment target of PSD in the future.

A sudden and severe depressive episode after a left cingulate gyrus stroke: a case report of post-stroke depression and review of literature

Post-stroke depression is a frequent complication of cerebrovascular lesions and mainly occurs within the first 6 months after stroke. Stroke patients who develop depression have slower recovery, greater disability, and higher mortality rates. The pathophysiology of post-stroke depression is not yet clearly defined, but studies suggest contributions from both psychosocial factors and stroke-related factors, such as lesions affecting the frontal-subcortical circuits. Early treatment has a positive impact on post-stroke rehabilitation outcome and survival. We present the case of an 82-year-old man with no psychiatric history who was brought to the psychiatric emergency department after two suicide attempts in the span of 7 days. He was severely depressed, with feelings of hopelessness, insomnia, and suicidal ideation. He had suffered a stroke the week before, affecting the anterior portion of the left cingulate gyrus, causing right hemiparesis and paresthesia. The psychiatric symptoms developed immediately after the stroke and were not present before the event. He was admitted to the psychiatry ward, treated with sertraline 100 mg/day and quetiapine 50 mg/day and discharged within 28 days, after full remission of symptoms. Our case strengthens the association between lesions located to the frontal-subcortical circuits and post-stroke depression. Physicians should be vigilant regarding the occurrence of depression in stroke patients, especially those who suffer lesions affecting the frontal-subcortical circuits and related regions.

Fluoxetine regulates eEF2 activity (phosphorylation) via HDAC1 inhibitory mechanism in an LPS-induced mouse model of depression

BACKGROUND

Selective serotonin reuptaker inhibitors, including fluoxetine, are widely studied and prescribed antidepressants, while their exact molecular and cellular mechanism are yet to be defined. We investigated the involvement of HDAC1 and eEF2 in the antidepressant mechanisms of fluoxetine using a lipopolysaccharide (LPS)-induced depression-like behavior model.

METHODS

For in vivo analysis, mice were treated with LPS (2 mg/kg BW), fluoxetine (20 mg/kg BW), HDAC1 activator (Exifone: 54 mg/kg BW) and NH125 (1 mg/kg BW). Depressive-like behaviors were confirmed via behavior tests including OFT, FST, SPT, and TST. Cytokines were measured by ELISA while Iba-1 and GFAP expression were determined by immunofluorescence. Further, the desired gene expression was measured by immunoblotting. For in vitro analysis, BV2 cell lines were cultured; treated with LPS, exifone, and fluoxetine; collected; and analyzed.

RESULTS

Mice treated with LPS displayed depression-like behaviors, pronounced neuroinflammation, increased HDAC1 expression, and reduced eEF2 activity, as accompanied by altered synaptogenic factors including BDNF, SNAP25, and PSD95. Fluoxetine treatment exhibited antidepressant effects and ameliorated the molecular changes induced by LPS. Exifone, a selective HDAC1 activator, reversed the antidepressant and anti-inflammatory effects of fluoxetine both in vivo and in vitro, supporting a causing role of HDAC1 in neuroinflammation allied depression. Further molecular mechanisms underlying HDAC1 were explored with NH125, an eEF2K inhibitor, whose treatment reduced immobility time, altered pro-inflammatory cytokines, and NLRP3 expression. Moreover, NH125 treatment enhanced eEF2 and GSK3β activities, BDNF, SNAP25, and PSD95 expression, but had no effects on HDAC1.

CONCLUSIONS

Our results showed that the antidepressant effects of fluoxetine may involve HDAC1-eEF2 related neuroinflammation and synaptogenesis.

miR-22 and cerebral microbleeds in brainstem and deep area are associated with depression one month after ischemic stroke

In this study, we aimed to explore the relationship among miR-22, deep cerebral microbleeds (CMBs), and post-stroke depression (PSD) 1 month after ischemic stroke. We consecutively recruited 257 patients with first-ever and recurrent acute cerebral infarction and performed PSD diagnosis in accordance with the Diagnostic and Statistical Manual IV criteria for depression. Clinical information, assessments of stroke severity, and imaging data were recorded on admission. We further detected plasma miR-22 using quantitative PCR and analyzed the relationship among miR-22, clinical data, and PSD using SPSS 23.0 software. Logistic regression showed that deep (OR=1.845, 95%CI: 1.006-3.386, P=0.047) and brain stem CMBs (OR=2.652, 95%CI: 1.110–6.921, P=0.040), as well as plasma miR-22 levels (OR=2.094, 95%CI: 1.066–4.115, P=0.032) were independent risk factors for PSD. In addition, there were significant differences in baseline National Institutes of Health Stroke Scale scores (OR=1.881, 95%CI: 1.180–3.011, P=0.007) and Widowhood scores (OR=1.903, 95%CI: 1.182–3.063, P=0.012). Analysis of the receiver operating curve (AUC=0.723, 95%CI: 0.562–0.883, P=0.016) revealed that miR-22 could predict PSD one month after ischemic stroke. Furthermore, plasma miR-22 levels in brainstem and deep CMBs patients showed an upward trend (P=0.028) relative to the others. Patients with acute ischemic stroke, having brainstem and deep cerebral microbleeds, or a higher plasma miR-22 were more likely to develop PSD. These findings indicate that miR-22 might be involved in cerebral microvascular impairment and post-stroke depression.

Optimizing functional outcome endpoints for stroke recovery studies

Novel therapeutic intervention that aims to enhance the endogenous recovery potential of the brain during the subacute phase of stroke has produced promising results. The paradigm shift in treatment approaches presents new challenges to preclinical and clinical researchers alike, especially in the functional endpoints domain. Shortcomings of the "neuroprotection" era of stroke research are yet to be fully addressed. Proportional recovery observed in clinics, and potentially in animal models, requires a thorough reevaluation of the methods used to assess recovery. To this end, this review aims to give a detailed evaluation of functional outcome measures used in clinics and preclinical studies. Impairments observed in clinics and animal models will be discussed from a functional testing perspective. Approaches needed to bridge the gap between clinical and preclinical research, along with potential means to measure the moving target recovery, will be discussed. Concepts such as true recovery of function and compensation and methods that are suitable for distinguishing the two are examined. Often-neglected outcomes of stroke, such as emotional disturbances, are discussed to draw attention to the need for further research in this area.

Echinochrome A Attenuates Cerebral Ischemic Injury through Regulation of Cell Survival after Middle Cerebral Artery Occlusion in Rat

Of late, researchers have taken interest in alternative medicines for the treatment of brain ischemic stroke, where full recovery is rarely seen despite advanced medical technologies. Due to its antioxidant activity, Echinochrome A (Ech A), a natural compound found in sea urchins, has acquired attention as an alternative clinical trial source for the treatment of ischemic stroke. The current study demonstrates considerable potential of Ech A as a medication for cerebral ischemic injury. To confirm the effects of Ech A on the recovery of the injured region and behavioral decline, Ech A was administered through the external carotid artery in a rat middle cerebral artery occlusion model after reperfusion. The expression level of cell viability-related factors was also examined to confirm the mechanism of brain physiological restoration. Based on the results obtained, we propose that Ech A ameliorates the physiological deterioration by its antioxidant effect which plays a protective role against cell death, subsequent to post cerebral ischemic stroke.

Multiple Combination of Angelica gigas Extract and Mesenchymal Stem Cells Enhances Therapeutic Effect

Alternative medicines attract attention because stroke is rarely expected to make a full recovery with the most advanced medical technology. Angelica gigas (AG) is a well-known herbal medicine as a neuroprotective agent. The present study introduced mesenchymal stem cells (MSCs) to identify for the advanced treatment of the cerebrovascular disease. The objective of this research is validation of the enhanced effects of multiple combined treatment of AG extract with MSCs on stroke through angiogenesis. Our results confirmed that AG extract with MSCs improved the neovascularization increasing expression of angiogenesis-regulated molecules. The changes of brain and the behavioral ability showed the increased effects of AG extract with MSCs. As a result, AG extract and MSCs may synergistically increase the therapeutic potential by enhancing neovascularization. This mixed approach provides a new experimental protocol of herbal medicine therapy for the treatment of a variety of diseases including stroke, trauma, and spinal cord injury.

Exploration of 27 plasma immune markers: a cross-sectional comparison of 64 old psychiatric inpatients having unipolar major depression and 18 non-depressed old persons

BACKGROUND

The prevalence of major depression (MD) according to population studies is the same for old (65 years and older) and younger adults. In contrast, an elevated proportion of old MD patients are hospitalized compared to younger adults with MD, indicating a need to expand the characteristics of old inpatients with MD. To illustrate this point, the association between inflammation and MD in old psychiatric inpatients is sparsely investigated even though an association between inflammation and treatment resistance among younger adults with MD has been reported. In this study, we aimed to explore the plasma concentrations of 27 immune markers in old inpatients with MD, and our purpose was to expand the understanding of inflammatory mechanisms in these patients.

METHODS

Prior to electroconvulsive treatment of MD, we compared 64 inpatients with unipolar MD (mean age 75.2 years) and 18 non-depressed controls (mean age 78.0 years). Symptoms characterizing MD were assessed by the Hamilton Rating Scale of Depression (HRSD)-17, and the immune markers from peripheral blood plasma were analysed using multiplex assay technology. For statistical analysis of data, we used the independent samples median test, independent samples t-test, χ²-test, receiver operating characteristic curve analyses, stepwise discriminant analysis, and multivariate linear regression.

RESULTS

Twenty-two immune markers representing pro- and anti-inflammatory, adaptive and trophic signalling had higher concentrations in the inpatients compared to the controls. Only the four immune markers IL-1β, IL-5, IL-10 and IL-15 had concentrations below the lower detection limit in a considerable portion (above 20%) of the patient cases. A combination of the concentration in plasma of TNF, vascular endothelial growth factor (VEGF), IL-1β, IL-7 and monocyte chemotactic protein (MCP)-1, correctly classified 98.4% of the depressed patients and 83.3% of the non-depressed controls. Plasma concentration of TNF and VEGF were associated with the HRSD-17 scores (p = 0.017 and 0.005, respectively).

CONCLUSIONS

Our results indicate that several inflammatory mechanisms may be highly activated in old psychiatric inpatients with MD, and indicate that immune markers may contribute to a more comprehensive understanding of MD in old persons.

TRIAL REGISTRATION

NCT01559324 ClinicalTrials.gov.

Salvia miltiorrhiza enhances the survival of mesenchymal stem cells under ischemic conditions

Objectives

To validate the enhanced therapeutic effect of Salvia miltiorrhiza Bunge (SM) for brain ischemic stroke through the anti‐apoptotic and survival ability of mesenchymal stem cells (MSCs).

Methods

The viability and the expression level of cell apoptotic and survival‐related proteins in MSCs by treatment of SM were assessed in vitro. In addition, the infarcted brain region and the behavioural changes after treatment of MSCs with SM were confirmed in rat middle cerebral artery occlusion (MCAo) models.

Key findings

We demonstrated that SM attenuates apoptosis and improves the cell viability of MSCs. In the rat MCAo model, the recovery of the infarcted region and positive changes of behaviour are observed after treatment of MSCs with SM.

Conclusions

The therapy using SM enhances the therapeutic effect for brain ischemic stroke by promoting the survival of MSCs. This synergetic effect thereby proposes a new experimental approach of traditional Chinese medicine and stem cell‐based therapies for patients suffering from a variety of diseases.

Neuroplasticity and behavioral effects of fluoxetine after experimental stroke

The brain can undergo self-repair and has the ability to compensate for functions lost after a stroke. The plasticity of the ischemic brain is influenced by several factors including aging and pharmacotherapy. Fluoxetine is an antidepressant which enhances serotonergic neurotransmission through selective inhibition of neuronal reuptake of serotonin. In clinical practice, fluoxetine alleviates the symptoms of post-stroke depression (PSD), helps motor recovery in stroke patients. In animal experiments, chronic administration of fluoxetine induces increased excitability of mature granule cells (GCs), enhancing axonal and dendritic reorganization, as well as promoting neurogenesis or angiogenesis in the dentate gurus (DG), but the effect of fluoxetine in the subventricular zone (SVZ) remains controversial. Meanwhile, chronic treatment with fluoxetine did not reverse age-dependent suppression of proliferation cells in the DG. Interestingly, although fluoxetine has been found to enhance neurogenesis in the DG in stroke rats, this property is not consistent with the behavioral recovery. More studies into this issue will be required to reveal how to translate enhanced neuronal plasticity into behavioral benefits. This review provides an update of the current knowledge about the neurogenesis and the fate of the newly generated cells after the use of fluoxetine, as well as its ability to promote a behavioral recovery after stroke in clinical and experimental results and attempts to define the therapeutic properties of fluoxetine in regenerative neuroscience.

Association Between Cerebral Microbleeds and Depression in the General Elderly Population: A Meta-Analysis

BACKGROUND

It remains unclear whether cerebral microbleeds (CMBs) are associated with depression in the general elderly population. We thus performed a meta-analysis to evaluate the relationship between depression and CMBs.

METHODS

A systematic literature search was conducted in EBSCO, PubMed, and Web of Science for relevant studies that assessed the relationship between depression and the prevalence of CMBs.

RESULTS

Five eligible studies including 7,328 patients were pooled in meta-analysis. The prevalence of CMBs was 18.0%. The prevalence of depression was 11.1%. The pooled analysis demonstrated odds ratio for CMBs and depression to be 1.187 (95% confidence interval 1.005-1.403; p = 0.043) with no evidence of statistical heterogeneity (I² = 0.0%, p = 0.621).

CONCLUSION

Our meta-analysis of available published data indicated an increased prevalence of depression in the subjects with pre-existing CMBs. This finding supports the vascular depression hypothesis. Further studies are needed to investigate the role of CMBs in the pathogenesis and progression of depression, which might provide a potential target for the prevention and treatment.

Enhancing Plasticity of the Central Nervous System: Drugs, Stem Cell Therapy, and Neuro-Implants

Stroke represents the first cause of adult acquired disability. Spontaneous recovery, dependent on endogenous neurogenesis, allows for limited recovery in 50% of patients who remain functionally dependent despite physiotherapy. Here, we propose a review of novel drug therapies with strong potential in the clinic. We will also discuss new avenues of stem cell therapy in patients with a cerebral lesion. A promising future for the development of efficient drugs to enhance functional recovery after stroke seems evident. These drugs will have to prove their efficacy also in severely affected patients. The efficacy of stem cell engraftment has been demonstrated but will have to prove its potential in restoring tissue function for the massive brain lesions that are most debilitating. New answers may lay in biomaterials, a steadily growing field. Biomaterials should ideally resemble lesioned brain structures in architecture and must be proven to increase functional reconnections within host tissue before clinical testing.

Chronic cerebral hypoperfusion induces post-stroke dementia following acute ischemic stroke in rats

BACKGROUND

Post-stroke dementia (PSD) is one of the major consequences after stroke. Chronic cerebral hypoperfusion (CCH) can induce vascular cognitive impairment and potentiate amyloid pathology. We investigated how CCH contributes to the development of PSD after stroke in the context of neuroinflammation and amyloid pathology.

METHODS

We designed a unique animal model for PSD. We performed middle cerebral artery occlusion (MCAO) surgery in rats mimicking acute territorial infarct, which was followed by bilateral common carotid artery occlusion (BCCAo) surgery mimicking CCH. We performed behavioral tests including neurologic function test and water maze task and histological investigations including neuroinflammation, neuronal cell death, amyloid pathology, and aquaporin 4 (AQP4) distribution.

RESULTS

Spatial memory was synergistically impaired when BCCAo was superimposed on MCAO. Neuroinflammation with astroglial or microglial activation and amyloid pathology were enhanced in the ipsilateral cortex, thalamus, and hippocampus when BCCAo was superimposed on MCAO. Glymphatic pathway-related AQP4 distribution changed from perivascular to parenchymal pattern.

CONCLUSIONS

Our experimental results suggest that CCH may contribute to the development of PSD by interfering with amyloid clearance through the glymphatic pathway and concomitant neuroinflammation. Therapeutic strategy to clear brain metabolic waste through the glymphatic pathway may be a promising approach to prevent PSD after stroke.

The Role of Neuropeptide Y mRNA Expression Level in Distinguishing Different Types of Depression

Previous studies demonstrate that the protein of neuropeptide Y (NPY) is abnormal in depression patients, but the changes of NPY in different types of depression are unclear. This study was aimed to examine protein and mRNA expression levels of NPY in 159 cases with four groups including post-stroke depression (PSD) group, stroke without depression (Non-PSD) group, major depressive disorder (MDD) group and normal control (NC) group. The protein and gene expression analysis were performed by enzyme-linked immunosorbent assay (ELISA) and quantitative polymerase chain reaction-based methods. One way analysis of variance (ANOVA), chi-square tests and nonparametric test were used to evaluate general characteristics, clinical and biological materials. In order to explore the role of NPY in different types of depression, the partial correlations, binary logistic regression analysis and receiver operating characteristic (ROC) curve were calculated for PSD and MDD groups. There are significant differences of NPY protein (F_df(3) = 5.167, P = 0.002) and mRNA expression levels (χKruskal2-Wallis, df(3) = 20.541, P < 0.001) among four groups. Bonferroni multiple comparisons found that the NPY protein was significantly decreased in PSD (F_Bonferroni = −7.133, P = 0.002) and Non-PSD group (F_Bonferroni = −5.612, P = 0.018) compared with NC group. However, contrasted with MDD group, the mRNA expression was increased in PSD and Non-PSD group by nonparametric test (all P < 0.05). In binary logistic analyses, NPY mRNA expression was independent predictors of PSD (odds ratio: 1.452, 95% CI, 1.081–1.951, P = 0.013). The ROC curve showed NPY mRNA had a general prognostic accuracy (area under the curve: 0.766, 95% CI, 0.656–0.876, P < 0.001). This is the first study to explore the distinguishing function of NPY in different types of depression. It will provide help in the identification of different subtypes of depression.