ErbB4 Receptors in the Medial Habenula Regulate Contextual Fear Memory.

The Medial Habenular (MHb) and the Lateral Habenular nuclei are 2 main parts of the habenular complex (Hb). Recent studies showed that MHb plays an important role in memory, and in the expression of ErbB4. However, the expression of MHb ErbB4 receptor and its role in fear memory is not well understood. In this study, western blotting and quantitative real-time polymerase chain reaction were used to assess the protein and mRNA levels of ErbB4 in the process of contextual fear conditioning. A pharmacological approach was used to block and stimulate the ErbB4 receptor. Contextual fear conditioning tests induced a significant increase on the expression of ErbB4 at various times in the Hb and the MHb. Moreover, the blockade and stimulation of MHb ErbB4 receptors did not affect the fear formation but impaired and improved the contextual-dependent fear expression. Furthermore, in vitro electrophysiological recordings showed that the blockade of the MHb ErbB4 receptor reduced the presynaptic gamma-amino butyric acid release. ErbB4 is a susceptible gene for schizophrenia and the above findings may provide new insights into the mechanisms of fear-related responses.

Dorsomedial prefrontal cortex 5-HT6 receptors regulate anxiety-like behavior.

The dorsomedial prefrontal cortex (dmPFC) plays a very important role in decision-related and anxiety-related information processing. It has enriched 5-HT6 receptors; however, the precise role of dmPFC 5-HT6 receptors in anxiety remains to be fully investigated. In this study, we injected dmPFC with the 5-HT6 receptor agonist EMD 386088 and antagonist SB 271046 using stereotactic technology. 5-HT6 receptor activation in mice increased time spent in the center area on the open-field test, increased exploration of the open arms on the elevated plus maze test, and increased ratio on the social interaction test. 5-HT6 receptor inactivation induced the opposite effects. In brain slices, EMD 386088 decreased both spontaneous inhibitory postsynaptic currents (sIPSC) and spontaneous excitatory postsynaptic currents (sEPSC), while SB 271046 only increased sEPSC. These effects of EMD 386088 and SB 271046 could be reversed by the GABAA receptor antagonist bicuculline (BMI) and positive allosteric modulator clonazepam (CLZ), respectively. Our results suggest that neurotransmission in the dmPFC by 5-HT6 receptor activation and inhibition may play an important role in anxiety-like behavior, and may provide new insight into the pathological mechanism and potential target of anxiety disorders.

Basilar artery hypoplasia associated with changes of brainstem potential, transcranial Doppler and perfusion-weighted imaging.

OBJECTIVE: The aim of this study was to observe brainstem hemodynamic alterations associated with basilar artery hypoplasia (BAH). METHODS: Nine hundred and fifty-two consecutive patients received emergency multimodal computed tomography; magnetic resonance imaging and magnetic resonance angiogram during the period of January 2011 to December 2014 were included. The vascular risk factors, brainstem auditory evoked potential (BAEP), blink reflex (BR), transcranial Doppler (TCD) and dynamic susceptibility contrast-enhanced perfusion-weighted imaging were completed. RESULTS: There was significant difference in the abnormal rates of TCD and BAEP between BAH and non-BAH patients. A positive correlation between basilar artery diameter and systolic velocity among BAH patients was suggested. V-wave value was used to predict posterior circulation infarction (PCI) with the sensitivity of 0.933 and specificity of 0.50 with the cutoff value of 5.97 s. Abnormal BR rate was also significantly different in BAH and non-BAH patients. The latency of R2 was used to predict PCI with the sensitivity of 0.933 and specificity of 0.50 with the cutoff value of 46.4 ms. The incidence of hypoperfusion was higher in BAH than non-BAH group and it was significant difference. CONCLUSION: BAH is closely associated with hemodynamic alterations within the pons, which might contribute to vascular vertigo due to regional hypoperfusion.

Vertebral Artery Hypoplasia and Posterior Circulation Infarction in Patients with Isolated Vertigo with Stroke Risk Factors.

BACKGROUND: We aimed in this study to investigate the prevalence of vertebral artery hypoplasia (VAH) in a population with isolated vertigo in association with stroke risk factors, to determine whether VAH is an independent risk factor for posterior circulation infarction (PCI). METHODS: We sequentially enrolled 245 patients with isolated vertigo with at least 1 vascular risk factor, who were divided into PCI and non-PCI groups, according to present signs of acute infarction on diffusion-weighted magnetic resonance imaging. All patients underwent magnetic resonance angiography and cervical contrast-enhanced magnetic resonance angiography to screen for VAH. Univariate and multivariate logistic regression analyses were performed to identify the significant risk factors for PCI. RESULTS: VAH was found in 64 of 245 patients (26%). VAH (odds ratio [OR] = 2.70, 95%confidence interval [CI] 1.17-6.23, P = .020), median stenosis of the posterior circulation (OR = 7.09, 95%CI = 2.54-19.79, P < .001), and diabetes mellitus (OR = 3.13, 95%CI 1.38-7.12, P = .006) were independent risk factors for PCI. The predominant Trial of Org 10172 in Acute Stroke Treatment subtype in our patients with isolated vertigo with PCI complicated by VAH was mainly small-artery occlusion. CONCLUSIONS: Our findings suggest that VAH is an independent risk factor for PCI in patients with isolated vertigo with confirmed risk from stroke.

MicroRNA-132 targets PEA-15 and suppresses the progression of astrocytoma in vitro.

Gliomas are highly malignant tumors, the most common of which are astrocytomas. A growing number of studies suggest that dysregulation of miRNAs is a frequent event contributing to the pathogenesis of gliomas. In this study, we found that over-expression of miR-132 inhibited cell proliferation and migration and triggered apoptosis, while knockdown of miR-132 showed opposite effects. PEA-15 was identified as a direct target of miR-132. Reintroduction of PEA-15 without 3'UTR region reversed the inhibitory effects of miR-132 on cell proliferation, migration, and apoptosis. MiR-132 was inversely correlated with the PEA-15 expression. CREB (cAMP response element binding protein) and KLF (Krüppel-like factor 8) were conformed as transcription factors of miR-132, which bidirectionally regulate the expression of miR-132. Our study suggests that miR-132 is an important tumor suppressor of astrocytoma progression by targeting PEA-15, while CREB and KLF can modulate the expression of miR-132, thus providing new insight into the molecular mechanisms underlying astrocytoma progression in vitro.

Pulmonary Hypertension Induces Serotonin Hyperreactivity and Metabolic Reprogramming in Coronary Arteries via NOX1/4-TRPM2 Signaling Pathway.

BACKGROUND: Clinical evidence revealed abnormal prevalence of coronary artery (CA) disease in patients with pulmonary hypertension (PH). The mechanistic connection between PH and CA disease is unclear. Serotonin (5-hydroxytryptamine), reactive oxygen species, and Ca2+ signaling have been implicated in both PH and CA disease. Our recent study indicates that NOXs (NADPH [nicotinamide adenine dinucleotide phosphate] oxidases) and TRPM2 (transient receptor potential cation channel subfamily M member 2) are key components of their interplay. We hypothesize that activation of the NOX-TRPM2 pathway facilitates the remodeling of CA in PH. METHODS: Left and right CAs from chronic hypoxia and monocrotaline-induced PH rats were collected to study vascular reactivity, gene expression, metabolism, and mitochondrial function. Inhibitors or specific siRNA were used to examine the pathological functions of NOX1/4-TRPM2 in CA smooth muscle cells. RESULTS: Significant CA remodeling and 5-hydroxytryptamine hyperreactivity in the right CA were observed in PH rats. NOX1/4-mediated reactive oxygen species production coupled with TRPM2-mediated Ca2+ influx contributed to 5-hydroxytryptamine hyperresponsiveness. CA smooth muscle cells from chronic hypoxia-PH rats exhibited increased proliferation, migration, apoptosis, and metabolic reprogramming in an NOX1/4-TRPM2-dependent manner. Furthermore, the NOX1/4-TRPM2 pathway participated in mitochondrial dysfunction, involving mitochondrial DNA damage, reactive oxygen species production, elevated mitochondrial membrane potential, mitochondrial Ca2+ accumulation, and mitochondrial fission. In vivo knockdown of NOX1/4 alleviated PH and suppressed CA remodeling in chronic hypoxia rats. CONCLUSIONS: PH triggers an increase in 5-hydroxytryptamine reactivity in the right CA and provokes metabolic reprogramming and mitochondrial disruption in CA smooth muscle cells via NOX1/4-TRPM2 activation. This signaling pathway may play an important role in CA remodeling and CA disease in PH.

Reduced CircSMOC1 Level Promotes Metabolic Reprogramming via PTBP1 (Polypyrimidine Tract-Binding Protein) and miR-329-3p in Pulmonary Arterial Hypertension Rats.

BACKGROUND: Pulmonary arterial hypertension maintains rapid cell proliferation and vascular remodeling through metabolic reprogramming. Recent studies suggested that circRNAs play important role in pulmonary vascular remodeling and pulmonary arterial smooth muscle cells proliferation. However, the relationship between circRNA, cell proliferation, and metabolic reprogramming in pulmonary arterial hypertension has not been investigated. METHODS: RNA-seq and qRT-PCR reveal the differential expression profile of circRNA in pulmonary arteries of pulmonary arterial hypertension rat models. Transfection was used to examine the effects of circSMOC1 on pulmonary artery smooth muscle cells, and the roles of circSMOC1 in vivo were investigated by adenoassociated virus. Mass spectrometry, RNA pull-down, RNA immunoprecipitation, and dual-luciferase reporter assay were performed to investigate the signaling pathway of circSMOC1 regulating the metabolic reprogramming. RESULTS: CircSMOC1 was significantly downregulated in pulmonary arteries of pulmonary arterial hypertension rats. CircSMOC1 knockdown promoted proliferation and migration and enhanced aerobic glycolysis of pulmonary artery smooth muscle cells. CircSMOC1 overexpression in vivo alleviates pulmonary vascular remodeling, right ventricular pressure, and right heart hypertrophy. In the nucleus, circSMOC1 directly binds to PTBP1 (polypyrimidine tract-binding protein), competitively inhibits the specific splicing of PKM (pyruvate kinase M) premRNA, resulting in the upregulation of PKM2 (pyruvate kinase M2), the key enzyme of aerobic glycolysis, to enhance glycolysis. In the cytoplasm, circSMOC1 acted as a miR-329-3p sponge, and its reduction in pulmonary arterial hypertension suppressed PDHB (pyruvate dehydrogenase E1 subunit beta) expression, leading to the impairment of mitochondrial oxidative phosphorylation. CONCLUSIONS: circSMOC1 is crucially involved in the metabolic reprogramming of pulmonary artery smooth muscle cells through PTBP1 and miR-329-3p to regulate pulmonary vascular remodeling in pulmonary arterial hypertension.

The emerging role of the MiR-1272-ADAM9-CDCP1 signaling pathway in the progression of glioma.

Glioma is a primary, malignant, and aggressive brain tumor in adults. To develop new therapeutic strategies for glioma, we must determine its underlying mechanisms. In the present study, we aimed to investigate the potential role of miR-1272-ADAM9-CDCP1 signaling in the progression of glioma. We found that ectopic expression of miR-1272 produced significant inhibitory effects on cell proliferation and migration and was associated with cell cycle G0/G1 arrest in A172 and SHG44 glioma cells. Using the luciferase reporter assay, we identified ADAM9 as a target of miR-1272. The expression of ADAM9 was markedly decreased or increased after overexpression or inhibition, respectively, of miR-1272 in glioma cells. Moreover, overexpression of ADAM9 reversed the inhibitory effects of miR-1272 on glioma cell progression. Furthermore, CDCP1 served as a potential downstream molecule of miR-1272/ADAM9 signaling in glioma and promoted the proliferation and migration of glioma. Results derived from clinical samples and online databases confirmed correlations between the expression of ADAM9 and CDCP1 and both the severity and prognosis of glioma. In conclusion, these results suggest that miR-1272 and CDCP1 may act as novel regulators in glioma. The miR-1272/ADAM9/CDCP1 pathway may serve as a potential candidate pathway for the prevention of glioma.

MicroRNA-26b-3p/ANTXR1 signaling modulates proliferation, migration, and apoptosis of glioma.

Glioma is a common malignant human brain tumor. The progression of glioma is associated with dysregulation of various microRNAs. Previous studies have demonstrated that microRNA-26b-3p (miR-26b-3p) is correlated with the pathogenesis of various tumors, but the functional role of miR-26b-3p and its underlying mechanisms in glioma are not clear. Here, we found that overexpression of miR-26b-3p repressed cell migration and proliferation and promoted apoptosis. In contrast, the opposite effects were observed when miR-26b-3p was inhibited in glioma cells. Anthrax toxin receptor 1 (ANTXR1) was confirmed to be a downstream molecule of miR-26b-3p. Reintroduction of ANTXR1 with an ORF region rescued the suppressive effects of miR-26b-3p on proliferation and migration, and inhibited the apoptosis of glioma cells. Moreover, the downstream target of miR-26b-3p, ANTXR1, was increased in glioma tissues and was inversely correlated with miR-26b-3p. MiR-26b-3p and ANTXR1 were correlated with the severity of glioma. Taken together, these results demonstrate that miR-26b-3p is a critical modulator of glioma via its downstream molecule, ANTXR1. Further, the miR-26b-3p/ANTXR1 axis may serve as a treatment or diagnostic target in glioma.

MicroRNA-6807-3p promotes the tumorigenesis of glioma by targeting downstream DACH1.

Accumulated evidence reveals that microRNAs play vital roles in various tumors, including gliomas. MiRNAs have been shown to participate in multiple cellular functions, including cell proliferation, migration and apoptosis. Here, we investigate the potential role of a novel miRNA, miR-6807-3p, in glioma. A quantitative reverse transcription-polymerase chain reaction (RT-qPCR) and western blot were applied to detect the expression of miR-6807-3p and its target molecule in glioma specimens and cultured cells. The direct targets of miR-6807-3p were predicted by bioinformatics software and were further verified by a luciferase reporter assay. The effects of miR-6807-3p on glioma cell proliferation, migration, cell apoptosis and the cell cycle of glioma cells were analyzed by the Cell-Counting Kit-8 (CCK-8) assay, a cell migration assay and flow cytometry assays. MiR-6807-3p was found to promote tumor growth and migration and inhibits apoptosis and cell cycle arrest in vitro, thus playing a tumor oncogenic role in the progression of glioma. Expression levels of miR-6807-3p were greatly upregulated in glioma specimens, and dachshund homolog 1 (DACH1) was ascertained as a direct target of miR-6807-3p, modulated by the expression of miR-6807-3p in glioma cells. Aberrant expression of DACH1 was associated with the clinical survival of glioma patients. Furthermore, overexpression of DACH1 rescued the promotive effects of miR-6807-3p in glioma. Based on these findings, a novel miR-6807-3p may act as a glioma enhancer by targeting DACH1.

MicroRNA-671-3p promotes proliferation and migration of glioma cells via targeting CKAP4.

BACKGROUND AND OBJECTIVE: Glioma is one of the most aggressive and malignant cancers originating from the human brain. Increasing evidence suggests that aberrant expression of microRNAs (miRNAs) frequently occurs in glioma and miRNAs are critical regulators of glioma. miR-671 has recently been revealed to be a novel miRNA that plays a vital role in human glioblastoma multiforme. However, the functional role and underlying mechanisms of miR-671-3p require further analysis. MATERIALS AND METHODS: Western blot and fluorescence quantitative PCR were used to assess the expression of cytoskeleton-associated protein 4 (CKAP4) and miR-671-3p, respectively. A Cell Counting Kit-8 (CCK-8) assay and a Boyden chamber assay were used to detect the proliferative and migratory abilities of glioma cells. A luciferase assay was used to determine the target gene of miR-671-3p. Apoptosis was analyzed by flow cytometry. RESULTS: Our results revealed that overexpression of miR-671-3p promoted cell proliferation and migration in vitro. Meanwhile, forced expression of miR-671-3p reduced apoptosis. In contrast, inhibition of miR-671-3p had the opposite effects. We also identified CKAP4 to be a direct target of miR-671-3p. The expression levels of CKAP4 were decreased in clinical samples and inversely correlated with miR-671-3p expression levels. Ectopic expression of CKAP4 reversed the promotive activity of miR-671-3p in the proliferation and migration and enhanced apoptosis. CONCLUSION: Our study demonstrates that miR-671-3p is a predominant positive regulator of glioma progression, thus providing new insights into the molecular mechanisms of glioma development. The findings suggest that the miR-6713p/CKAP4 axis may serve as a potential therapeutic target or biomarker in glioma.

Vertebral artery hypoplasia, posterior circulation infarction and relative hypoperfusion detected by perfusion magnetic resonance imaging semiquantitatively.

Vertebral artery hypoplasia (VAH) has been considered a risk factor of posterior circulation infarction (PCI), especially in the territory of the posterior inferior cerebellar artery (PICA). But whether VAH is an independent risk factor for PCI remains uncertain and how VAH participates in the evolvement of PCI is still not clear either. Therefore, this study aims to examine whether VAH is an independent risk factor for PCI and evaluate the effect of VAH on the cerebral perfusion in the territory of the PICA detected by perfusion magnetic resonance imaging (MRI) semiquantitatively. Both univariate and multivariate analyses showed that VAH, hypertension and smoking were more frequent in patients with PCI than in patients without PCI. Perfusion MRI analysis found that there were remarkable differences in the frequency of the relative cerebral blood flow (rCBF) value ≤0.85 and the relative time to peak (rTTP) values between VAH patients without PCI and non-VAH patients without PCI. Our results indicated that VAH may be an independent risk factor for PCI, especially in the presence of hypertension and smoking and that a relative hypoperfusion associates with VAH that may contribute to the evolvement of the infarction in the PICA territory.