Exosome Transplantation From Patients With Schizophrenia Causes Schizophrenia-Relevant Behaviors in Mice: An Integrative Multi-omics Data Analysis

Exosomes are involved in the pathophysiology of neuropsychiatric diseases, but the role of exosomes in schizophrenia (SCZ) is unclear. Here, we demonstrate that transplantation of serum exosomes from SCZ patients into mice caused behavioral abnormalities such as deficits in prepulse inhibition and sociability, hyperactivity, and anxiogenesis. A comparative bioinformatics analysis suggested shared and distinct differentially expressed genes (DEGs) and enriched molecular pathways in the brains of SCZ exosome-recipient mice, methylazoxymethanol acetate-treated rats, and SCZ patients, which correlates evidence of altered prefrontal–hippocampal functional coherence in SCZ. A large proportion of SCZ-relevant DEGs in the exosome-recipient mice were targets of DE exosomal miRNAs in SCZ patients. Furthermore, we identified 20 hub genes for SCZ risk genes, including BDNF and NRG1, which were DE miRNA targets in SCZ. Collectively, our study suggests that SCZ exosome transplantation caused SCZ-relevant behaviors in mice, and epigenetic regulation may contribute to the phenotypes in the SCZ exosome-recipient mice. Our results may provide a potential animal model and novel therapeutic targets for SCZ.     

Differential expression of gut miRNAs in idiopathic Parkinson's disease

ObjectiveIn the present work, we aimed to investigate the expression of microRNAs (miRNAs) in routine colonic biopsies obtained from patients with idiopathic Parkinson's disease (PD) and to address their value as a diagnostic biomarker for PD and their mechanistic contribution to PD onset and progression.MethodsPatients with PD (n = 13) and healthy controls (n = 17) were prospectively recruited to undergo routine colonic biopsies for cancer screening. Total RNA was extracted from the biopsy material and the expression of miRNAs was quantified by Illumina High-Throughput Sequencing.ResultsStatistical analysis revealed a significant submucosal enrichment of the miRNA hsa-miR-486–5p in colonic biopsies from PD patients compared to the control subjects. The expression of miR-486–5p correlated with age and disease severity as measured by the UPDRS and Hoehn & Yahr scale. miRNA gene target analysis identified 301 gene targets that are affected by miR-486–5p. A follow-up associated target identification and pathway enrichment analysis further determined their role in distinct biological processes in the enteric nervous system (ENS).InterpretationOur work demonstrates an enrichment of submucosal miR-486–5p in routine colonic biopsies from PD patients. Our results will support the examination of miR-486–5p as a PD biomarker and help to understand the significance of the miR-486–5p gene targets for PD onset and progression. In addition, our data will support the investigation of the molecular and cellular mechanisms of GI dysfunction in PD.     

Altered microRNA regulation in Huntington's disease models

Huntington's disease (HD) is a genetic neurodegenerative disease caused by abnormal CAG expansion. MicroRNAs (miRNAs) are short RNA molecules regulating gene expression, and are implicated in a variety of diseases including HD. However, the profiles and regulation of miRNAs in HD are not fully understood. Here, we analyzed the miRNA expression and miRNA regulators in two transgenic models of HD, YAC128 and R6/2 mice, and in a 3-nitropropionic acid (3NP)-induced striatal degeneration rat model. After characterizing the phenotypes by behavioral tests and histological analyses, we profiled striatal miRNAs using a miRNA microarray and we measured the key molecules involved in miRNA biogenesis and function. YAC128 mice showed upregulation-dominant miRNA expressions at 5 months and downregulation-dominant expressions at 12 months. Concomitantly, the expressions of Drosha-DGCR8, Exportin-5, and Dcp1 were increased at 5 months, and the expression of Dicer was decreased at 12 months. In 10-week-old R6/2 mice, downregulation was dominant in the miRNA expressions and the level of Drosha decreased concomitantly. Nine miRNAs (miR-22, miR-29c, miR-128, miR-132, miR-138, miR-218, miR-222, miR-344, and miR-674*) were commonly down-regulated in both the 12-month-old YAC128 and 10-week-old R6/2 mice. Meanwhile, 3NP rats showed dynamic changes in the miRNA profiles during disease development and a few miRNAs with altered expression. Our results show that transgenic HD mice have abnormal miRNA biogenesis. This information should aid in future studies on therapeutic application of miRNAs in HD.     

Amygdalar expression of proteins associated with neuroplasticity in major depression and suicide

Introduction

Doublecortin (DCX) and polysialilated neural cell adhesion molecule (PSA-NCAM), two proteins associated with immature neuronal phenotypes and elevated neuroplasticity in the adult brain, have recently been identified in the mammalian amygdala, and evidence from rodent studies suggests that stress may modify their expression in this brain region. The purpose of the present study was to investigate whether the expression of proteins involved in neuroplasticity is altered in the amygdala of individuals with depression.

Methods

Basolateral amygdala (BLA) and central amygdala (CeA) postmortem human brain samples were collected from individuals with a history of depression (n = 22 and 25, respectively) and psychiatrically healthy controls (CTRL; n = 14). Proteins associated with neuroplasticity were quantified using Western blotting.

Results

Immunoblots revealed that depressed subjects displayed increased expression of DCX (p = 0.033) and PSA-NCAM (p = 0.027) in the BLA as compared to CTRLs. Subsequent analyses revealed that this effect was due primarily to a subset of depressed subjects who had not died by suicide (DNS). DNS subjects displayed higher DCX than CTRLs (p < 0.001) and depressed suicides (p = 0.001), and higher PSA-NCAM than CTRLs (p = 0.007). Conversely, within the CeA, DNS subjects displayed a tendency toward lower DCX expression than CTRLs (p = 0.062), and higher BDNF levels than DS subjects (p = 0.045).

Conclusion

These results suggest that the BLA and CeA display contrasting patterns of neuroplasticity in depression, and that greater impairment of amygdalar neuroplasticity may be associated with increased risk of suicide.     

Patterns of microRNA expression in normal and early Alzheimer’s disease human temporal cortex: white matter versus gray matter

MicroRNA (miRNA) expression was assessed in human cerebral cortical gray matter (GM) and white matter (WM) in order to provide the first insights into the difference between GM and WM miRNA repertoires across a range of Alzheimer's disease (AD) pathology. RNA was isolated separately from GM and WM portions of superior and middle temporal cerebral cortex (N = 10 elderly females, postmortem interval < 4 h). miRNA profiling experiments were performed using state-of-the-art Exiqon^© LNA-microarrays. A subset of miRNAs that appeared to be strongly expressed according to the microarrays did not appear to be conventional miRNAs according to Northern blot analyses. Some well-characterized miRNAs were substantially enriched in WM as expected. However, most of the miRNA expression variability that correlated with the presence of early AD-related pathology was seen in GM. We confirm that downregulation of a set of miRNAs in GM (including several miR-15/107 genes and miR-29 paralogs) correlated strongly with the density of diffuse amyloid plaques detected in adjacent tissue. A few miRNAs were differentially expressed in WM, including miR-212 that is downregulated in AD and miR-424 which is upregulated in AD. The expression of certain miRNAs correlates with other miRNAs across different cases, and particular subsets of miRNAs are coordinately expressed in relation to AD-related pathology. These data support the hypothesis that patterns of miRNA expression in cortical GM may contribute to AD pathogenetically, because the aggregate change in miRNA expression observed early in the disease would be predicted to cause profound changes in gene expression.     

<Emphasis Type="Italic">ERBB4</Emphasis> polymorphism and family history of psychiatric disorders on age-related cortical changes in healthy children

Genetic variations in ERBB4 were associated with increased susceptibility for schizophrenia (SCZ) and bipolar disorders (BPD). Structural imaging studies showed cortical abnormalities in adolescents and adults with SCZ or BPD. However, less is known about subclinical cortical changes or the influence of ERBB4 on cortical development. 971 healthy children (ages 3–20 years old; 462 girls and 509 boys) were genotyped for the ERBB4-rs7598440 variants, had structural MRI, and cognitive evaluation (NIH Toolbox ®). We investigated the effects of ERBB4 variants and family history of SCZ and/or BPD (FH) on cortical measures and cognitive performances across ages 3–20 years using a general additive model. Variations in ERBB4 and FH impact differentially the age-related cortical changes in regions often affected by SCZ and BPD. The ERBB4-TT-risk genotype children with no FH had subtle cortical changes across the age span, primarily located in the left temporal lobe and superior parietal cortex. In contrast, the TT-risk genotype children with FH had more pronounced age-related changes, mainly in the frontal lobes compared to the non-risk genotype children. Interactive effects of age, FH and ERBB4 variations were also found on episodic memory and working memory, which are often impaired in SCZ and BPD. Healthy children carrying the risk-genotype in ERBB4 and/or with FH had cortical measures resembling those reported in SCZ or BPD. These subclinical cortical variations may provide early indicators for increased risk of psychiatric disorders and improve our understanding of the effect of the NRG1–ERBB4 pathway on brain development.     

Down-regulation of inflammation-protective microRNAs 146a and 212 in monocytes of patients with postpartum psychosis

BackgroundPostpartum psychosis (PP) is thought to belong to the bipolar spectrum. Recently we described an immune activation signature in monocytes of patients with PP using gene expression profiling. Immune activation genes are regulated by microRNAs (miRNAs). We therefore profiled miRNA expression in monocytes of PP patients to identify differentially expressed miRNAs between PP and the healthy state.MethodsIn a profiling study we carried out miRNA profiling using TaqMan array human microRNA A cards v2.0 and monocytes of 8 PP patients. Data were analyzed against monocytes of healthy postpartum women (CP). Nine miRNAs were selected and tested using individual Q-PCR in a larger validation study on monocytes of 20 PP patients, 20 CP and 20 healthy non-postpartum women (HC).ResultsIn the validation study miR-146a expression was significantly down-regulated in the monocytes of first onset PP patients as compared to CP and HC; miR-212 expression was significantly down-regulated in PP patients with prior bipolar disorder. In silico miR-146a targeted 4 genes of the previously described monocyte activation signature in bipolar disorder; miR-212 targeted 2 of such genes. In a correlation study decreased expression of miR-146a in monocytes was related to decreased natural T regulator cells in PP patients; decreased miR-212 was correlated to increased Adrenomedulin and decreased IL-6 expression in monocytes and to higher Th2 cell levels.ConclusionsThis study identified changes in miR-146a and -212 expression in PP. Since these miRNAs are linked to inflammation, the study strengthens the view that PP is an inflammation-like condition.     

Bioinformatics and microarray analysis of microRNA expression profiles of murine embryonic stem cells,neural stem cells induced from ESCs and isolated from E8·5 mouse neural tube

Abstract

To better understand whether microRNAs (miRNAs) are involved in the self-renewal of stem cells and fate determination of neural stem cells and to identify the miRNA expression patterns of different neural stem cells (NSC) in vitro and in vivo, we examined miRNA expression profiles of murine embryonic stem cells (ESC), NSC induced from ESC and isolated from E8·5 mouse neural tube (E8·5-NSC) using microarray technique. It was found that a total of 40 miRNAs had similar expression level in all the three cells [false discovery rate (FDR)=0, fold change <3·0]. Moreover, q-PCR showed that some members of miR-106b and miR-17–92 families were expressed in the ESC, NSC induced from ESC (ESC-NSC) and hematopoietic stem cells (HSC). Bioinformatical analysis showed that 'stemness genes' (p21/CDKN1A, p57/CDKN1C and PTEN) were putative targets of miR-106b and miR-17–92 families. A total of 95 miRNAs were found to experience significant change (FDR=0, fold change >5·0) when the ESC differentiated into NSC. On the basis of miRNA, mRNA expression variance and predicted target genes of miRNA, we formulated a bioinformatical model for miRNA control of ESC-NSC differentiation. Then, the miRNA expression pattern was compared between NSC obtained in vitro and in vivo, and it was found that only 8% of miRNAs were different between the two NSCs. This study suggested that miR-106b and miR-17–92 families may promote the renewal of stem cells by targeting PTEN, p21/CDKN1A and p57/CDKN1C. Some miRNAs may play a key role in gene re-programming during ESC-NSC differentiation, and a substantial homogeneity exists between NSCs derived in vitro and those in vivo.     

A preliminary analysis of association between the down-regulation of microRNA-181b expression and symptomatology improvement in schizophrenia patients before and after antipsychotic treatment

Despite the growing evidences on the relation of altered expression of miRNAs and schizophrenia, most schizophrenia subjects have an extensive antipsychotic treatment history and the pharmacological effects on miRNA expression are largely unknown. This study aimed to investigate the change of plasma microRNA-181b level and improvement of symptomatology before and after six-week antipsychotic treatment in schizophrenia patients, and explore their association. A total of 20 schizophrenia patients absent of antipsychotics and 20 age-and gender-matched normal controls were enrolled, and tested for 9 schizophrenia-associated microRNA (miR-30e, miR-34a, miR-181b, miR-195, miR-346, miR-432, miR-7, miR-132 and miR-212) expression levels in plasma using quantitative RT-PCR and for symptomatology improvement using Positive And Negative Syndrome Scale (PANSS) before and after treatment (olanzapine, quetiapine, ziprasidone and risperidone) for the patients only. Compared with the normal control group, the expression levels of miRNA-181b, miRNA-30e, miRNA-34a and miRNA-7 of the patients group were significantly higher (p < 0.05). Compared with those before treatment in the patient group, the symptomatology scores were significantly lower (p < 0.001), and the expression level of microRNA-181b was significantly down-regulated after treatment (p < 0.05). The change of miRNA-181b expression was positively correlated with the improvement of negative symptoms and lack of response symptoms (r = 0.502 and 0.557, P < 0.05, accounting for 20.2% and 26.4% respectively), and their therapeutic effects with OR being 11.283 and 5.119 respectively. We conclude that miRNA-181b, miRNA-30e, miRNA-34a and miRNA-7 are probably involved in pathogenesis of SZ, and the significant down-regulation of miRNA-181b expression predicts improvement of negative symptoms to treatment, and thus can serve as a potential plasmamolecular marker for antipsychotic responses.     

Circulating miR-126 and miR-130a levels correlate with lower disease risk,disease severity,and reduced inflammatory cytokine levels in acute ischemic stroke patients

To investigate the correlations of five angiogenesis-related miRNA (miR-126, miR-130a, miR-222, miR-218, and miR-185) expression levels with risk, severity, and inflammatory cytokines levels in acute ischemic stroke (AIS) patients. A total of 148 AIS patients and 148 age- and gender-matched controls were consecutively enrolled. Blood samples were collected from AIS patients and controls, and plasma was separated for miRNAs and cytokine level detection. Plasma levels of miRNAs were evaluated by real-time qPCR method, and inflammatory cytokine levels were detected using an enzyme-linked immunosorbent assay (ELISA). Plasma miR-126 and miR-130a expression levels in AIS patients were lower than those of controls, while the levels of miR-222, miR-218, and miR-185 were elevated in AIS patients compared with controls. After pooling the five miRNA expression levels together, the area under the curve (AUC) for predicting AIS risk was 0.840 (95% CI 0.795–0.885) with a sensitivity of 83.8% and a specificity of 69.6% at the best cut-off point. Plasma miR-126 (r?=???0.402, P?<?0.001) and miR-130a (r?=???0.161, P?=?0.050) levels were negatively correlated with NIHSS scores, while plasma miR-218 level was positively correlated with NIHSS scores (r?=?0.471, P?<?0.001). Most importantly, plasma miR-126 expression was negatively correlated with TNF-α (r?=???0.168, P?=?0.041), IL-1β (r?=???0.246, P?=?0.003), and IL-6 (r?=???0.147, P?=?0.035) levels, while miR-130a expression was negatively correlated with TNF-α (r?=???0.287, P?<?0.001), IL-1β (r?=???0.168, P?=?0.041), and IL-6 (r?=???0.239, P?=?0.003) expression levels and positively associated with IL-10 level (r?=?0.261, P?=?0.001). Circulating miR-126 and miR-130a levels correlate with lower disease risk, decreased disease severity, and reduced inflammatory cytokine levels in AIS patients.     

Genome-Wide Sequencing Reveals MicroRNAs Downregulated in Cerebral Cavernous Malformations

Cerebral cavernous malformations (CCM) are vascular lesions associated with loss-of-function mutations in one of the three genes encoding KRIT1 (CCM1), CCM2, and PDCD10. Recent understanding of the molecular mechanisms that lead to CCM development is limited. The role of microRNAs (miRNAs) has been demonstrated in vascular pathologies resulting in loss of tight junction proteins, increased vascular permeability and endothelial cell dysfunction. Since the relevance of miRNAs in CCM pathophysiology has not been elucidated, the primary aim of the study was to identify the miRNA-mRNA expression network associated with CCM. Using small RNA sequencing, we identified a total of 764 matured miRNAs expressed in CCM patients compared to the healthy brains. The expression of the selected miRNAs was validated by qRT-PCR, and the results were found to be consistent with the sequencing data. Upon application of additional statistical stringency, five miRNAs (let-7b-5p, miR-361-5p, miR-370-3p, miR-181a-2-3p, and miR-95-3p) were prioritized to be top CCM-relevant miRNAs. Further in silico analyses revealed that the prioritized miRNAs have a direct functional relation with mRNAs, such as MIB1, HIF1A, PDCD10, TJP1, OCLN, HES1, MAPK1, VEGFA, EGFL7, NF1, and ENG, which are previously characterized as key regulators of CCM pathology. To date, this is the first study to investigate the role of miRNAs in CCM pathology. By employing cutting edge molecular and in silico analyses on clinical samples, the current study reports global miRNA expression changes in CCM patients and provides a rich source of data set to understand detailed molecular machinery involved in CCM pathophysiology.     

microRNAs miR-124, let-7d and miR-181a regulate Cocaine-induced Plasticity

MicroRNAs play key regulatory roles in cellular processes including neurogenesis, synapse development and plasticity in the brain. Psychostimulants induces strong neuroadaptive changes through a surfeit of gene regulatory mechanisms leading to addiction. MicroRNA profiling for identifying miRNAs regulating cocaine-induced, plasticity-related genes revealed significant regulation of a set of miRNAs upon cocaine administration, especially let-7d, miR-181a and the brain-specific miR-124. These miRNAs target many genes involved in cocaine addiction. Precursor and mature miRNA quantification by qRT-PCR showed that miR-124 and let-7d are significantly downregulated, whereas miR-181a is induced in the mesolimbic dopaminergic system under chronic cocaine administration. Results were confirmed by in situ hybridization, Northern blots, FISH analysis and RNase protection assay. Using lentiviral-mediated miRNA expression, we show a significant downregulation of BDNF and D3R both at mRNA and protein levels by miR-124 and let-7d, respectively. Our data suggest that miR-124, let-7d and miR-181a may be involved in a complex feedback loop with cocaine-responsive plasticity genes, highlighting the possibility that some miRNAs are key regulators of the reward circuit and may be implicated in addiction.     

miR-98 and let-7g* protect the blood–brain barrier under neuroinflammatory conditions

Pathologic conditions in the central nervous system, regardless of the underlying injury mechanism, show a certain level of blood–brain barrier (BBB) impairment. Endothelial dysfunction is the earliest event in the initiation of vascular damage caused by inflammation due to stroke, atherosclerosis, trauma, or brain infections. Recently, microRNAs (miRNAs) have emerged as a class of gene expression regulators. The relationship between neuroinflammation and miRNA expression in brain endothelium remains unexplored. Previously, we showed the BBB-protective and anti-inflammatory effects of glycogen synthase kinase (GSK) 3β inhibition in brain endothelium in in vitro and in vivo models of neuroinflammation. Using microarray screening, we identified miRNAs induced in primary human brain microvascular endothelial cells after exposure to the pro-inflammatory cytokine, tumor necrosis factor-α, with/out GSK3β inhibition. Among the highly modified miRNAs, let-7 and miR-98 were predicted to target the inflammatory molecules, CCL2 and CCL5. Overexpression of let-7 and miR-98 in vitro and in vivo resulted in reduced leukocyte adhesion to and migration across endothelium, diminished expression of pro-inflammatory cytokines, and increased BBB tightness, attenuating barrier ‘leakiness'' in neuroinflammation conditions. For the first time, we showed that miRNAs could be used as a therapeutic tool to prevent the BBB dysfunction in neuroinflammation.