Amygdala neuronal dyshomeostasis via 5-HT receptors mediates mood and cognitive defects in Alzheimer's disease.

Behavioral changes or neuropsychiatric symptoms (NPSs) are common features in dementia and are associated with accelerated cognitive impairment and earlier deaths. However, how NPSs are intertwined with cognitive decline remains elusive. In this study, we identify that the basolateral amygdala (BLA) is a key brain region that is associated with mood disorders and memory decline in the AD course. During the process from pre- to post-onset in AD, the dysfunction of parvalbumin (PV) interneurons and pyramidal neurons in the amygdala leads to hyperactivity of pyramidal neurons in the basal state and insensitivity to external stimuli. We further demonstrate that serotonin (5-HT) receptors in distinct neurons synergistically regulate the BLA microcircuit of AD rather than 5-HT levels, in which both restrained inhibitory inputs by excessive 5-HT1AR signaling in PV interneurons and depolarized pyramidal neurons via upregulated 5-HT2AR contribute to aberrant neuronal hyperactivity. Downregulation of these two 5-HT receptors simultaneously enables neurons to resist ß-amyloid peptides (Aß) neurotoxicity and ameliorates the mood and cognitive defects. Therefore, our study reveals a crucial role of 5-HT receptors for regulating neuronal homeostasis in AD pathogenesis, and this would provide early intervention and potential targets for AD cognitive decline.

Construction of a lncRNA-associated competing endogenous RNA regulatory network after traumatic brain injury in mouse.

Traumatic brain injury (TBI) is a major public health problem worldwide which causes high mortality and disability. Functioning as microRNA (miRNA) sponges, long non-coding RNA (lncRNA) regulates the expression of protein-coding genes in a competing endogenous RNA (ceRNA) network. However, the lncRNA-associated ceRNA in TBI remains unclear. In this study, we processed the raw SRR files of mice cortex samples of sham injury (n = 3) and TBI groups (n = 3) to count files. Then, the expression profiles of lncRNAs and mRNAs were identified, and 86 differentially expressed (DE) lncRNAs and 1201 DEmRNAs between sham and TBI groups were identified. The DEmRNAs were used to perform enrichment analyses. Next, a lncRNA-miRNA-mRNA regulatory ceRNA network was constructed. The network consisted of 23 mRNAs, 5 miRNAs and 2 lncRNAs. The expression alternations of the 5 miRNAs were validated via qRT-PCR. The subnetwork of hub lncRNA Neat1 was extracted. We identified a potential inflammatory associated regulatory axis: Neat1/miR-31-5p/Myd88 axis. The PPI network based on DEmRNA involved in ceRNA network was constructed PPI networks to identify the hub genes. Finally, DElncRNAs and DEmRNAs were selected randomly and validated by qRT-PCR. In conclusion, with the lncRNA-miRNA-mRNA ceRNA network provided above, we can improve our understanding of the regulatory mechanisms and interaction among lncRNAs, miRNAs and mRNAs in TBI process.

Construction of competitive endogenous RNA network reveals regulatory role of long non-coding RNAs in intracranial aneurysm.

BACKGROUND: Rupture of intracranial aneurysm (IA) is the main cause of devastating subarachnoid hemorrhage, which urges our understanding of the pathogenesis and regulatory mechanisms of IA. However, the regulatory roles of long non-coding RNAs (lncRNAs) in IA is less known. RESULTS: We processed the raw SRR files of 12 superficial temporal artery (STA) samples and 6 IA samples to count files. Then the differentially expressed (DE) mRNAs, miRNAs, and lncRNAs between STAs and IAs were identified. The enrichment analyses were performed using DEmRNAs. Next, a lncRNA-miRNA-mRNA regulatory network was constructed using integrated bioinformatics analysis. In summary, 341 DElncRNAs, 234 DEmiRNAs, and 2914 DEmRNAs between the STA and IA. The lncRNA-miRNA-mRNA regulatory network of IA contains 91 nodes and 146 edges. The subnetwork of hub lncRNA PVT1 was extracted. The expression level of PVT1 was positively correlated with a majority of the mRNAs in its subnetwork. Moreover, we found that several mRNAs (CCND1, HIF1A, E2F1, CDKN1A, VEGFA, COL1A1 and COL5A2) in the PVT1 subnetwork served as essential components in the PI3K-Akt signaling pathway, and that some of the non-coding RNAs (ncRNAs) (PVT1, HOTAIR, hsa-miR-17, hsa-miR-142, hsa-miR-383 and hsa-miR-193b) interacted with these mRNAs. CONCLUSION: Our annotations noting ncRNA's role in the pathway may uncover novel regulatory mechanisms of ncRNAs and mRNAs in IA. These findings provide significant insights into the lncRNA regulatory network in IA.

Lactate-induced M2 polarization of tumor-associated macrophages promotes the invasion of pituitary adenoma by secreting CCL17.

Background: Lactate greatly contributes to the regulation of intracellular communication within the tumor microenvironment (TME). However, the role of lactate in pituitary adenoma (PA) invasion is unclear. In this study, we aimed to clarify the effects of lactate on the TME and the effects of TME on PA invasion. Methods: To explore the correlation between TME acidosis and tumor invasion, LDHA and LAMP2 expression levels were quantified in invasive (n = 32) and noninvasive (n = 32) PA samples. The correlation between immune cell infiltration and tumor invasion was evaluated in 64 PAs. Critical chemokine and key signaling pathway components were detected by qPCR, Western blotting, siRNA knockdown, and specific inhibitors. The functional consequences of CCR4 signaling inhibition were evaluated in vitro and in vivo. Results: Lactate was positively associated with PA invasion. Of the 64 PA tissues, invasive PAs were related to high infiltration of M2-like tumor-associated macrophages (TAMs) (P < 0.05). Moreover, lactate secreted from PA cells facilitated M2 polarization via the mTORC2 and ERK signaling pathways, while activated TAMs secreted CCL17 to promote PA invasion via the CCL17/CCR4/mTORC1 axis. According to univariate analysis of clinical data, high CCL17 expression was associated with larger tumor size (P = 0.0438), greater invasion (P = 0.0334), and higher susceptibility to postoperative recurrence (P = 0.0195) in human PAs. Conclusion: This study illustrates the dynamics between PA cells and immune TME in promoting PA invasion via M2 polarization. CCL17 levels in the TME are related to the PA invasiveness and clinical prognosis, and the CCL17/CCR4/mTOCR1 axis may serve as potential therapeutic targets for Pas.

Hippocampal Lnx1-NMDAR multiprotein complex mediates initial social memory.

Social interaction and communication are evolutionary conserved behaviours that are developed in mammals to establish partner cognition. Deficit in sociability has been represented in human patients and animal models of neurodevelopmental disorders, which are connected with genetic variants of synaptic glutamate receptors and associated PDZ-binding proteins. However, it remains elusive how these key proteins are specialized in the cellular level for the initial social behaviour during postnatal developmental stage. Here we identify a hippocampal CA3 specifically expressed PDZ scaffold protein Lnx1 required for initial social behaviour. Through gene targeting we find that Lnx1 deficiency led to a hippocampal subregional disorder in neuronal activity and social memory impairments for partner discrimination observed in juvenile mice which also show cognitive defects in adult stage. We further demonstrate that Lnx1 deletion causes NMDA receptor (NMDAR) hypofunction and this is attributable to decreased GluN2B expression in PSD compartment and disruption of the Lnx1-NMDAR-EphB2 complex. Specific restoration of Lnx1 or EphB2 protein in the CA3 area of Lnx1-/- mice rescues the defective synaptic function and social memory. These findings thus reveal crucial roles of postsynaptic NMDAR multiprotein complex that regulates the formation of initial social memory during the adolescent period.

Transcriptome Analyses Reveal Systematic Molecular Pathology After Optic Nerve Crush.

The function of glial cells in axonal regeneration after injury has been the subject of controversy in recent years. Thus, deeper insight into glial cells is urgently needed. Many studies on glial cells have elucidated the mechanisms of a certain gene or cell type in axon regeneration. However, studies that manipulate a single variable may overlook other changes. Here, we performed a series of comprehensive transcriptome analyses of the optic nerve head over a period of 90 days after optic nerve crush (ONC), showing systematic molecular changes in the optic nerve head (ONH). Furthermore, using weighted gene coexpression network analysis (WGCNA), we established gene module programs corresponding to various pathological events at different times post-ONC and found hub genes that may be potential therapeutic targets. In addition, we analyzed the changes in different glial cells based on their subtype markers. We revealed that the transition trend of different glial cells depended on the time course, which provides clues for modulating glial function in further research.

Prognostic and Predictive Value of a Long Non-coding RNA Signature in Glioma: A lncRNA Expression Analysis.

The current histologically based grading system for glioma does not accurately predict which patients will have better outcomes or benefit from adjuvant chemotherapy. We proposed that combining the expression profiles of multiple long non-coding RNAs (lncRNAs) into a single model could improve prediction accuracy. We included 1,094 glioma patients from three different datasets. Using the least absolute shrinkage and selection operator (LASSO) Cox regression model, we built a multiple-lncRNA-based classifier on the basis of a training set. The predictive and prognostic accuracy of the classifier was validated using an internal test set and two external independent sets. Using this classifier, we classified patients in the training set into high- or low-risk groups with significantly different overall survival (OS, HR = 8.42, 95% CI = 4.99-14.2, p < 0.0001). The prognostic power of the classifier was then assessed in the other sets. The classifier was an independent prognostic factor and had better prognostic value than clinicopathological risk factors. The patients in the high-risk group were found to have a favorable response to adjuvant chemotherapy (HR = 0.4, 95% CI = 0.25-0.64, p < 0.0001). We built a nomogram that integrated the 10-lncRNA-based classifier and four clinicopathological risk factors to predict 3 and 5 year OS. Gene set variation analysis (GSVA) showed that pathways related to tumorigenesis, undifferentiated cancer, and epithelial-mesenchymal transition were enriched in the high-risk groups. Our classifier built on 10-lncRNAs is a reliable prognostic and predictive tool for OS in glioma patients and could predict which patients would benefit from adjuvant chemotherapy.

Maf1 regulates dendritic morphogenesis and influences learning and memory.

Maf1, a general transcriptional regulator and mTOR downstream effector, is highly expressed in the hippocampus and cortex, but the function of Maf1 in neurons is not well elucidated. Here, we first demonstrate that Maf1 plays a central role in the inhibition of dendritic morphogenesis and the growth of dendritic spines both in vitro and in vivo. Furthermore, Maf1 downregulation paradoxically leads to activation of AKT-mTOR signaling, which is mediated by decreased PTEN expression. Moreover, we confirmed that Maf1 could regulate the activity of PTEN promoter by luciferase reporter assay, and proved that Maf1 could bind to the promoter of PTEN by ChIP-PCR experiment. We also demonstrate that expression of Maf1 in the hippocampus affects learning and memory in mice. Taken together, we show for the first time that Maf1 inhibits dendritic morphogenesis and the growth of dendritic spines through AKT-mTOR signaling by increasing PTEN expression.

Paroxetine ameliorates prodromal emotional dysfunction and late-onset memory deficit in Alzheimer's disease mice.

BACKGROUND: Neuropsychiatric symptoms (NPS) such as depression, anxiety, apathy, and irritability occur in prodromal phases of clinical Alzheimer's disease (AD), which might be an increased risk for later developing AD. Here we treated young APP/PS1 AD model mice prophylactically with serotonin-selective re-uptake inhibitor (SSRI) paroxetine and investigated the protective role of anti-depressant agent in emotional abnormalities and cognitive defects during disease progress. METHODS: To investigate the protective role of paroxetine in emotional abnormalities and cognitive defects during disease progress, we performed emotional behaviors of 3 months old APP/PS1 mouse following oral administration of paroxetine prophylactically starting at 1 month of age. Next, we tested the cognitive, biochemical and pathological, effects of long term administration of paroxetine at 6 months old. RESULTS: Our results showed that AD mice displayed emotional dysfunction in the early stage. Prophylactic administration of paroxetine ameliorated the initial emotional abnormalities and preserved the eventual memory function in AD mice. CONCLUSION: Our data indicate that prophylactic administration of paroxetine ameliorates the emotional dysfunction and memory deficit in AD mice. These neuroprotective effects are attributable to functional restoration of glutamate receptor (GluN2A) in AD mice.

Integrated Transcriptome Analyses and Experimental Verifications of Mesenchymal-Associated TNFRSF1A as a Diagnostic and Prognostic Biomarker in Gliomas.

Gliomas are the most prevalent malignant primary brain tumors with poor outcome, and four different molecular subtypes (Mesenchymal, Proneural, Neural, and Classical) are popularly applied in scientific researches and clinics of gliomas. Public databases contain an abundant genome-wide resource to explore the potential biomarker and molecular mechanisms using the informatics analysis. The aim of this study was to discover the potential biomarker and investigate its effect in gliomas. Weighted gene co-expression network analysis (WGCNA) was used to construct the co-expression modules and explore the biomarker among the dataset CGGA mRNAseq_693 carrying 693 glioma samples. Functional annotations, ROC, correlation, survival, univariate, and multivariate Cox regression analyses were implemented to investigate the functional effect in gliomas, and molecular experiments in vitro were performed to study the biological effect on glioma pathogenesis. The brown module was found to be strongly related to WHO grade of gliomas, and KEGG pathway analysis demonstrated that TNFRSF1A was enriched in MAPK signaling pathway and TNF signaling pathway. Overexpressed TNFRSF1A was strongly related to clinical features such as WHO grade, and functioned as an independent poor prognostic predictor of glioma patients. Notably, TNFRSF1A was preferentially upregulated in the Mesenchymal subtype gliomas (Mesenchymal-associated). Knockdown of TNFRSF1A inhibited proliferation and migration of glioma cell lines in vitro. Our findings provide a further understanding of the progression of gliomas, and Mesenchymal-associated TNFRSF1A might be a promising target of diagnosis, therapy, and prognosis of gliomas.

Prognosis of colorectal cancer patients is associated with the novel log odds of positive lymph nodes scheme: derivation and external validation.

Background and aim: To construct proper and externally validate cut-off points for log odds of positive lymph nodes scheme (LODDS) staging scheme in colorectal cancer (CRC). Patients and methods: The X-tile approach was used to find the cut-off points for the novel LODDS staging scheme in 240,898 patients from the Surveillance, Epidemiology and End Results (SEER) database and externally validated in 1,878 from the international multicenter cohort. Kaplan-Meier plot and multivariate Cox proportional hazard models were performed to investigate the role of the novel LODDS classification. Results: The prognostic cut-off values were determined as -2.18, and -0.23 (P< 0.001). Patients had 5-year cancer-specific survival rates of 83.8%, 57.4% and 24.4% with increasing LODDS (P< 0.001) in the SEER database. Five-year overall survival rates were 77.2%, 55.0% and 26.7% with increasing LODDS (P< 0.001) in the external international multicenter cohort. Multivariate survival analysis identified both the LODDS classification, the patient's age, the T category, the M status, and the tumor grade as independent prognostic factors in both two independent databases. The analyses of the subgroup of patients stratified by tumor location (colon or rectum), number of retrieved lymph node (< 12 or ≥ 12), TNM stage III, lymph node-negative also confirmed the LODDS as independent prognostic factors (P< 0.001) in both two independent databases. Conclusions: The novel LODDS classification was an independent prognostic factor for patients with CRCs and should be calculated for additional risk group stratification with pN scheme.

Young-Onset Early Colorectal Cancer Had Similar Relative Survival to but Better Overall Survival Than Conventional Early Colorectal Cancer: A Large Population-Based Study.

Background: There existed limited evidence about prognosis of young-onset early colorectal cancer (ECRC). In the present study, we aimed to compare prognosis between patients with young-onset ECRCs and patients with conventional ECRCs. Method: Patients with surgically resected, histologically diagnosed ECRCs were retrieved from the Surveillance, Epidemiology, and End Results (SEER) database. Young-onset ECRC was defined as ECRC occurring in patients aged <50 years. Five-years relative survival was calculated at the time of diagnosed year and linear regression was performed to analyze the association between 5-years relative survival and age. The multivariate Cox regression, multivariate competing risk model, and propensity score matching (PSM) and univariate analysis weighted by the inverse probability of treatment weight (IPTW) were used to compare overall survival (OS) between young-onset ECRCs and conventional ECRCs. Results: A total of 51,197 ECRCs were retrieved from SEER database, including 4,634 young-onset ECRCs and 46,563 conventional ECRCs. Five-years relative survival was found to be moderately associated with different age groups (R = -0.725, P = 0.0034). Patients with young-onset ECRCs (96.7%) had similar 5-years relative survival compared with conventional ECRCs (96.3%). However, multivariate Cox regression [HR (hazard ratio), 0.18; 95% CI: 0.16-0.20; P < 0.001] showed better OS in young-onset ECRCs. After PSM, we still found favored prognosis for young-onset ECRCs under univariate Cox regression (HR, 0.18; 95% CI: 0.16-0.21; P < 0.001). Similar results could also be found in the univariate Cox regression weighted by IPTW (HR, 0.17; 95% CI: 0.17-0.18; P < 0.001). Conclusions: Patients with young-onset ECRCs had similar relative survival but better OS compared with conventional ECRCs.

Transcriptome analyses reveal molecular mechanisms underlying phenotypic differences among transcriptional subtypes of glioblastoma.

Using molecular signatures, previous studies have defined glioblastoma (GBM) subtypes with different phenotypes, such as the proneural (PN), neural (NL), mesenchymal (MES) and classical (CL) subtypes. However, the gene programmes underlying the phenotypes of these subtypes were less known. We applied weighted gene co-expression network analysis to establish gene modules corresponding to various subtypes. RNA-seq and immunohistochemical data were used to validate the expression of identified genes. We identified seven molecular subtype-specific modules and several candidate signature genes for different subtypes. Next, we revealed, for the first time, that radioresistant/chemoresistant gene signatures exist only in the PN subtype, as described by Verhaak et al, but do not exist in the PN subtype described by Phillips et al PN subtype. Moreover, we revealed that the tumour cells in the MES subtype GBMs are under ER stress and that angiogenesis and the immune inflammatory response are both significantly elevated in this subtype. The molecular basis of these biological processes was also uncovered. Genes associated with alternative RNA splicing are up-regulated in the CL subtype GBMs, and genes pertaining to energy synthesis are elevated in the NL subtype GBMs. In addition, we identified several survival-associated genes that positively correlated with glioma grades. The identified intrinsic characteristics of different GBM subtypes can offer a potential clue to the pathogenesis and possible therapeutic targets for various subtypes.

Identification of biomarkers and construction of a microRNA-mRNA regulatory network for ependymoma using integrated bioinformatics analysis.

Ependymomas (EPNs) are one of the most common types of malignant neuroepithelial tumors. In an effort to identify potential biomarkers involved in the pathogenesis of EPN, the mRNA expression profiles of the GSE25604, GSE50161, GSE66354, GSE74195 and GSE86574 datasets, in addition to the microRNA (miRNA/miR) expression profiles of GSE42657 were downloaded from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) and differentially expressed miRNAs (DEMs) between EPN and normal brain tissue samples were identified using the Limma package in R and GEO2R, respectively. Functional and pathway enrichment analyses were conducted using the Database for Annotation, Visualization and Integrated Discovery. A protein-protein interaction network was constructed using the Search Tool for Retrieval of Interacting Genes database, which was visualized using Cytoscape. The targeted genes of DEMs were predicted using miRWalk2.0 and a miRNA-mRNA regulatory network was constructed. Following analysis, a total of 948 DEGs and 129 DEMs were identified. Functional enrichment analysis revealed that 609 upregulated DEGs were significantly enriched in 'PI3K-Akt signaling pathway', while 339 downregulated DEGs were primarily involved in 'cell junction' and 'retrograde endocannabinoid signaling'. In addition, 6 hub genes [cyclin dependent kinase 1, CD44 molecule (Indian blood group) (CD44), proliferating cell nuclear antigen (PCNA), MYC, synaptotagmin 1 (SYT1) and kinesin family member 4A] and 6 crucial miRNAs [homo sapiens (hsa)-miR-34a-5p, hsa-miR-449a, hsa-miR-106a-5p, hsa-miR-124-3p, hsa-miR-128-3p and hsa-miR-330-3p] were identified as biomarkers and potential therapeutic targets for EPN. Furthermore, a microRNA-mRNA regulatory network was constructed to highlight the interactions between DEMs and their target DEGs; this included the hsa-miR-449a-SYT1, hsa-miR-34a-5p-SYT1, hsa-miR-330-3p-CD44 and hsa-miR-124-3p-PCNA pairs, whose expression levels were confirmed using reverse transcription-quantitative polymerase chain reaction. In conclusion, the present study may provide important data for the investigation of the molecular mechanisms of EPN pathogenesis.

A combination of glioma in vivo imaging and in vivo drug delivery by metal-organic framework based composite nanoparticles.

The success of glioma chemotherapy is hampered by low intratumoral drug concentration and severe toxicity in normal organs. Glioma diagnosis and total tumor resection depend on enhanced magnetic resonance imaging (MRI) results which provide the best solution for recognizing tumor mass anatomical details with high spatial resolution. Zeolite imidazole frameworks (ZIFs) have pore channel tunability, large specific surface area and porosity, and have broad application prospects in adsorption, catalysis and drug loading. However, there are few reports on post-synthesis ZIF-8 based multifunctional nanocomposites as a theranostic agent for in vivo diagnostic and therapeutic applications simultaneously. In this study, we synthesized a low toxicity bimetallic zeolitic imidazolate framework (Mn-ZIF-8) with good dispersibility and high specific surface area, which could be used for potential high drug loading. Meanwhile, we used Mn-ZIF-8 for the first time for in vivo MRI. T1-weighted MR signals at tumor sites continuously increased over time after injecting Mn-ZIF-8 intravenously. Moreover, 12 hours after injecting Mn-ZIF-8 into a nude mouse bearing U87-MG tumor, a relatively high accumulation of Mn2+ in tumors was observed, probably due to the EPR effect of cancerous tumors. Targeted delivery significantly improves the therapeutic efficacy of Mn-ZIF-8/5-Fu in U87-MG tumor-bearing mice, resulting in 80% survival rate over 40 days of treatment. Mn-ZIF-8/5-Fu has excellent in vivo biocompatibility at a given dose, which induces minimal side effects on the functions of important organs. Therefore, efficient 5-Fu loaded Mn-ZIF-8 with favorable in vivo biocompatibility, pH responsiveness and T1-weighted contrast MRI of tumors can be used as a promising framework for diagnostic and therapeutic applications in the case of glioma simultaneously.

Effect of α7nAChR on learning and memory dysfunction in a rat model of diffuse axonal injury.

Diffuse axonal injury (DAI) is the predominant effect of severe traumatic brain injury and significantly contributes to cognitive deficits. The mechanisms that underlie these cognitive deficits are often associated with complex molecular alterations. α7nAChR, one of the abundant and widespread nicotinic acetylcholine receptors (nAChRs) in the brain, plays important physiological functions in the central nervous system. However, the relationship between temporospatial alterations in the α7nAChR and DAI-related learning and memory dysfunction are not completely understood. Our study detected temporospatial alterations of α7nAChR in vulnerable areas (hippocampus, internal capsule, corpus callosum and brain stem) of DAI rats and evaluated the development and progression of learning and memory dysfunction via the Morris water maze (MWM). We determined that α7nAChR expression in vulnerable areas was mainly reduced at the recovery of DAI in rats. Moreover, the escape latency of the injured group increased significantly and the percentages of the distance travelled and time spent in the target quadrant were significantly decreased after DAI. Furthermore, α7nAChR expression in the vulnerable area was significantly positively correlated with MWM performance after DAI according to regression analysis. In addition, we determined that a selective α7nAChR agonist significantly improved learning and memory dysfunction. Rats in the α7nAChR agonist group showed better learning and memory performance than those in the antagonist group. These results demonstrate that microstructural injury-induced alterations of α7nAChR in the vulnerable area are significantly correlated with learning and memory dysfunctions after DAI and that augmentation of the α7nAChR level by its agonist contributes to the improvement of learning and memory function.

Examining the biomarkers and molecular mechanisms of medulloblastoma based on bioinformatics analysis.

Medulloblastoma (MB) is the most common malignant brain tumor in children. The aim of the present study was to predict biomarkers and reveal their potential molecular mechanisms in MB. The gene expression profiles of GSE35493, GSE50161, GSE74195 and GSE86574 were downloaded from the Gene Expression Omnibus (GEO) database. Using the Limma package in R, a total of 1,006 overlapped differentially expressed genes (DEGs) with the cut-off criteria of P<0.05 and |log2fold-change (FC)|>1 were identified between MB and normal samples, including 540 upregulated and 466 downregulated genes. Furthermore, the Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were also performed using the Database for Annotation, Visualization and Integrated Discovery (DAVID) online tool to analyze functional and pathway enrichment. The Search Tool for Retrieval of Interacting Genes database was subsequently used to construct a protein-protein interaction (PPI) network and the network was visualized in Cytoscape. The top 11 hub genes, including CDK1, CCNB1, CCNB2, PLK1, CDC20, MAD2L1, AURKB, CENPE, TOP2A, KIF2C and PCNA, were identified from the PPI network. The survival curves for hub genes in the dataset GSE85217 predicted the association between the genes and survival of patients with MB. The top 3 modules were identified by the Molecular Complex Detection plugin. The results indicated that the pathways of DEGs in module 1 were primarily enriched in cell cycle, progesterone-mediated oocyte maturation and oocyte meiosis; and the most significant functional pathways in modules 2 and 3 were primarily enriched in mismatch repair and ubiquitin-mediated proteolysis, respectively. These results may help elucidate the pathogenesis and design novel treatments for MB.

A neuronal molecular switch through cell-cell contact that regulates quiescent neural stem cells.

The quiescence of radial neural stem cells (rNSCs) in adult brain is regulated by environmental stimuli. However, little is known about how the neurogenic niche couples the external signal to regulate activation and transition of quiescent rNSCs. Here, we reveal that long-term excitation of hippocampal dentate granule cells (GCs) upon voluntary running leads to activation of adult rNSCs in the subgranular zone and thereby generation of newborn neurons. Unexpectedly, the role of these excited GC neurons in NSCs depends on direct GC-rNSC interaction in the local niche, which is through down-regulated ephrin-B3, a GC membrane-bound ligand, and attenuated transcellular EphB2 kinase-dependent signaling in the adjacent rNSCs. Furthermore, constitutively active EphB2 kinase sustains the quiescence of rNSCs during running. These findings thus elucidate the physiological significance of GC excitability on adult rNSCs under external environments and indicate a key-lock switch regulation via cell-cell contact for functional transition of rNSCs.

Inhibition of miRNA-21 promotes retinal ganglion cell survival and visual function by modulating Müller cell gliosis after optic nerve crush.

BACKGROUND: Müller cell gliosis not only plays an important physiological role by maintaining retinal neuronal homeostasis but is also associated with multiple pathological events in the retina, including optic nerve crush (ONC) injury. Modulating Müller cell gliosis contributes to the creation of a permissive environment for neuronal survival. However, the underlying mechanism of Müller cell gliosis has remained elusive. OBJECTIVE: To investigate the underlying mechanism of Müller cell gliosis after ONC. METHODS: Rats with ONC injury were transfected with miRNA-21 (miR-21) agomir (overexpressing miR-21) or antagomir (inhibiting miR-21) via intravitreous injection. Immunofluorescence and western blotting were performed to confirm the effects of miR-21 on Müller cell gliosis. The retinal nerve fiber layer (RNFL) thickness was measured using optical coherence tomography and the positive scotopic threshold response (pSTR) was recorded using electroretinogram. RESULTS: In the acute phase (14 days) after ONC, compared with the crushed group, inhibiting miR-21 promoted Müller cell gliosis, exhibiting thicker processes and increased GFAP expression. In the chronic phase (35 days), inhibiting miR-21 ameliorated Müller cell gliosis, which exhibited thicker and denser processes and increased GFAP expression. Retinal ganglion cell (RGC) counts in retinas showed that the number of surviving RGCs increased significantly in the antagomir group. The thickness of the RNFL increased significantly, and pSTR showed significant preservation of the amplitudes in the antagomir group. CONCLUSIONS: Inhibition of miR-21 promotes RGC survival, RNFL thickness and the recovery of RGC function by modulating Müller cell gliosis after ONC.