Phosphodiesterase 4 Inhibitor Roflupram Suppresses Inflammatory Responses Using Reducing Inflammasome in Microglia After Spinal Cord Injury.

Context: Neuroinflammation after spinal cord injury (SCI) can lead to long-term damage in neural tissue, which can cause the destruction and dysfunction of the neurological system. Roflupram (ROF), a selective phosphodiesterase 4 inhibitor, may play a protective role against neuropathological diseases, but the specific role of ROF in SCI treatment is unknown. Objective: The study intended to investigate the anti-inflammatory mechanism and therapeutic effects of ROF to determine if it can attenuate lipopolysaccharide (LPS)-induced microglia that induces neuroinflammation and decrease neural-tissue damage following an SCI. Design: The research team performed an animal study. Setting: The study took place at the Fourth Affiliated Hospital of Harbin Medical University in Harbin, China. Animals: The animals were female C57BL/6 mice, aged 8 weeks and weighing approximately 20 g. Intervention: For the in-vitro study, the research team divided BV2 microglial cells into three groups: (1) the control group, which received no LPS stimuli and no ROF treatment, (2) the LPS group, which received LPS stimuli but no ROF treatment, and (3) LPS+ROF group, which received both LPS stimuli and ROF treatment. For the in-vivo study, the research team randomly divided the mice into three groups: (1) the sham group, for which the team didn't induce SCI and which received no ROF treatment (2) the SCI group, for which the team induced SCI but which received no ROF treatment, and (3) the SCI+ROF group, for which the team induced SCI and which received the ROF treatment. Outcome Measures: The research team evaluated: (1) the cell viability of the BV2 microglia cells after five doses of ROF and the RNA levels of inflammatory-activation-related factors, the inflammatory pathway; (2) in-vitro inhibition of inflammation in LPS-activated microglia; (3) the anti-neuroinflammatory role of ROF after SCI induction in vitro; and (4) the role of ROF in neural-structure protection and locomotor-function recovery in vitro. Results: In the in-vitro study, the ROF attenuated microglial inflammation through the inhibition of the NLRP3 inflammasome in vitro, reduced neuroinflammation, and protected against neuronal loss. In the in-vivo study with mice, the ROF: (1) improved the functional recovery of locomotor skills after induction of SCI; (2) acted in an anti-inflammatory role in SCI, restraining microglial inflammation by inhibition of the "nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3" (NLRP3) inflammasome and reduction of caspase-1-dependent, interleukin-1 beta (IL)-1ß; and (3) reduced neuronal death and protected against tissue loss, improving functional recovery after an SCI. Conclusions: The current study demonstrated that ROF can reduce the levels of inflammation in the tissue after spinal cord injury by modulating the AMPK/NLRP3 signaling pathway, thereby promoting the recovery of motor function in mice. ROF is a promising drug for prevention of neural-tissue damage following neural injury.

Zileuton Ameliorates Neuronal Ferroptosis and Functional Recovery After Spinal Cord Injury.

Context: Ferroptosis is a novel type of cell-death pattern characterized by iron-dependent, oxidative stress, and lipid peroxidation. Neurological pathology, especially in spinal cord injury (SCI), may involve a trace amount of ferroptosis. However, it's uncertain whether zileuton (ZIL), a selective 5-lipoxygenase (5-LO) inhibitor, can inhibit ferroptosis in SCI. Objective: The study intended to investigate the etiology of neuronal ferroptosis and the ameliorative effects of ZIL against it for SCI mice. Design: The research team performed an animal study. Setting: The study took place at the Fourth Affiliated Hospital of Harbin Medical University in Harbin, China. Animals: The animals were adult, male, C57BL/6 mice, about 20 to 25 g in weight. Intervention: The research team: (1) stimulated HT22 cells, an immortalized mouse hippocampal neuronal cell line treated with erastin, and mice induced spinal cord trauma using a moderate hit, and (2) treated the cells and mice with ZIL. Outcome measures: The research team measured: (1) motor function, (2) neurological damage, (3) iron content, (4) lipid oxidation, and (5) neuroinflammation and glial response. Results: ZIL administration attenuated ferroptosis and lipid peroxidation in the HT22 cells. Moreover, ZIL mitigated the ferroptosis and inflammation in the injured spinal cords. Hence, ZIL can decrease neurological damage and improve recovery of motor function, indicating an ameliorative role for ZIL in SCI. Conclusions: ZIL has anti-ferroptosis and anti-oxidative effects in neurons, which can contribute to recovery of motor function after induction of SCI. ZIL is a promising drug for inhibiting ferroptosis and protecting neurological functions after induction of SCI.

MiR-34a Inhibits Cell Proliferation and Induces Apoptosis in Human Nasopharyngeal Carcinoma by Targeting lncRNA MCM3AP-AS1.

INTRODUCTION: MCM3AP-AS1 has been characterized as an oncogenic lncRNA in several types of cancer, while its role in nasopharyngeal carcinoma (NPC) is unknown. This study aimed to investigate the role of MCM3AP-AS1 in NPC. PATIENTS AND METHODS: Paired NPC tissues and non-tumor tissues were collected from 55 NPC patients. Expression of MCM3AP-AS1 and miR-34a in paired tissues was analyzed by RT-qPCR. Interactions between MCM3AP-AS1 and miR-34a were analyzed by overexpression experiments. The roles of MCM3AP-AS1 and miR-34a in regulating NPC cell proliferation and apoptosis were explored by cell proliferation assay and cell apoptosis assay, respectively. RESULTS: Our bioinformatics analysis showed that MCM3AP-AS1 may be targeted by miR-34a, which is a well-studied tumor suppressor miRNA. In this study, we showed that miR-34a was downregulated and MCM3AP-AS1 was upregulated in NPC. An inverse correlation between the expression of MCM3AP-AS1 and miR-34a was found across NPC tissue samples. High expression level of MCM3AP-AS1 and low levels of miR-34a in NPC tissues predicted the poor survival. In NPC cells, overexpression of MCM3AP-AS1 did not affect the expression of miR34a, while overexpression of miR-34a led to downregulated MCM3AP-AS1. Cell proliferation and apoptosis assay showed that overexpression of miR-34a reduced the enhancing effects of overexpressing MCM3AP-AS1 on cell proliferation and the inhibitory effects on cell apoptosis. CONCLUSION: MiR-34a inhibits cell proliferation and induces apoptosis in human NPC by targeting MCM3AP-AS1.

High-Dose Static and Dynamic Intensity-Modulated Radiotherapy Combined with Chemotherapy for Patients with Locally Advanced Nasopharyngeal Carcinoma Improves Survival and Reduces Brainstem Toxicity.

BACKGROUND Intensity-modulated radiotherapy (IMRT) is the standard treatment for patients with nasopharyngeal cancer (NPC). However, the dose-volume criteria for adjacent anatomically normal organs at risk (OARs) remain controversial. The aim of this study was to evaluate the effects of higher than conventional doses of static and dynamic IMRT on the locoregional control of NPC, patient survival, and brainstem radiation toxicity. MATERIAL AND METHODS Patients (n=186) with stage III and stage IVa NPC underwent high-dose static and dynamic IMRT treatment (68-76.96 Gy) with or without chemotherapy for 34-57 days. Overall survival (OS), the presence of distant metastases, and brainstem toxicity were assessed. One-year, three-year, and five-year follow-up was performed. RESULTS High-dose IMRT alone or in combination with chemotherapy resulted in a 100% objective response rate and significantly improved OS rates, with one-year, three-year, and five-year OS rates of 94.1%, 89.8%, and 88.2%, respectively. The local recurrence rate (17.6%), and distant metastasis to the lung, liver, and bone (17.2%), and mortality (n=22) were reduced. Chemotherapy was the only factor that was significantly correlated with patient survival. Brainstem toxicity was reduced in patients treated with static IMRT (0.07%) and dynamic IMRT (0.08%). There were 26 additional factors that were not found to significantly affect brainstem toxicity. CONCLUSIONS High-dose static or dynamic IMRT combined with chemotherapy improved survival and reduces distal metastasis with a very low occurrence of brainstem toxicity in patients with locally advanced NPC. These findings might provide therapeutic guidance for clinicians when planning optimal dose-volume IMRT parameters.

A polysaccharide from Polygonatum sibiricum attenuates amyloid-ß-induced neurotoxicity in PC12 cells.

One of the pathological hallmarks of Alzheimer's disease (AD) is the progressive accumulation of beta-amyloid (Aß) in the form of senile plaques, and Aß induced neurotoxicity has been identified as a major cause of the onset of AD. In this study, we investigated the protective effects of a polysaccharide (PS-WNP) from Polygonatum sibiricum against the Aß(25-35)-induced neurotoxicity in PC12 cells and explored the underlying mechanism. The results showed that pretreatment with PS-WNP significantly attenuated cell death and the elevated Bax/Bcl-2 ratio evoked by Aß(25-35), and subsequently inhibited mitochondrial dysfunction and cytochrome c release into the cytosol. Moreover, PS-WNP significantly inhibited Aß(25-35) induced caspase-3 activation and enhanced the protein levels of phosphorylated Akt (p-Akt) in PC12 cells. Additionally, pretreatment with the PI3K inhibitor (LY294002) completely abolished the protective effects of PS-WNP against Aß(25-35)-induced neuronal cell apoptosis. These observations unambiguously suggested that the protective effect of PS-WNP against Aß(25-35)-induced apoptosis in PC12 cells was associated with the enhancement of PI3K/Akt signaling pathway.

A novel NF-κB/MMP-3 signal pathway involves in the aggressivity of glioma promoted by Bmi-1.

Matrix metalloproteinase 3 (MMP-3) is implicated in the pathogenesis and progression of glioma. However, whether MMP-3 participates in the regulation of metastasis and its mechanisms in glioma is mostly unknown. In the present study, glioma cells were stably transfected with Bmi-1 small interfering RNA (siRNA) to knockdown off Bmi-1 or were transiently transfected with Bmi-1 complementary DNA (cDNA) to upregulate the Bmi-1 level and to evaluate their effects on invasion and expression analysis for molecules involved in invasion. Knockdown of Bmi-1 dramatically reduced a nuclear factor kappa B (NF-κB) and MMP-3 expression and activity in T98G cells. When the T98G cells were upregulated in the Bmi-1 levels, the T98G cells were treated with 10 µM BAY 11-7028 to inhibit the NF-κB activity. The invasion induced by upregulation of Bmi-1 was severely abolished by BAY 11-7028 in Bmi-1 overexpression cells. The T98G cell metastatic potential was increased by overexpression of Bmi-1; completely at the same time, the NF-κB activity and MMP-3 expression was also increased. Taken together, these findings suggest that Bmi-1 promotes glioma cell migration and invasion via NF-κB-mediated upregulation of MMP-3.

Harmine mediated neuroprotection via evaluation of glutamate transporter 1 in a rat model of global cerebral ischemia.

Global cerebral ischemia (GCI) causes energy deficiency results in excessive release of glutamate from neurons. Astrocytic glutamate transporters play a predominant role in keeping extracellular glutamate concentrations below excitotoxic levels. Glutamate transporter 1 (GLT-1) may account for more than 90% of glutamate uptake in adult forebrain. Preclinical findings implicate that Harmine present neuroprotection effects in a rat model of amyotrophic lateral sclerosis disease, and the beneficial effects were specifically due to up-regulation of GLT-1. However, no experiments have explored the potential of Harmine to provide neuroprotection in the setting of GCI. The current study was designed to determine whether Harmine could attenuate cerebral infarction as well as improve neuronal survival after GCI. Furthermore, to test whether the mechanisms were associated with up-regulating of GLT-1, we used a GLT-1 specific inhibitor dihydrokainate (DHK) and analysis the expression of GLT-1 mRNA and protein in cortex of brain. We also examined whether Harmine treatment affected astrocytes activation via immunofluorescence. Our results showed that post-GCI administration of Harmine could attenuate cerebral infarct volume and decrease neurons death. It also caused significantly elevation of GLT-1 mRNA and protein and remarkably attenuation of astrocyte activation. We provide novel clues in understanding the mechanisms of which Harmine exerts its neuroprotective activity in neurological disorders.

Cortical GABAergic neurons are more severely impaired by alkalosis than acidosis.

BACKGROUND: Acid-base imbalance in various metabolic disturbances leads to human brain dysfunction. Compared with acidosis, the patients suffered from alkalosis demonstrate more severe neurological signs that are difficultly corrected. We hypothesize a causative process that the nerve cells in the brain are more vulnerable to alkalosis than acidosis. METHODS: The vulnerability of GABAergic neurons to alkalosis versus acidosis was compared by analyzing their functional changes in response to the extracellular high pH and low pH. The neuronal and synaptic functions were recorded by whole-cell recordings in the cortical slices. RESULTS: The elevation or attenuation of extracellular pH impaired these GABAergic neurons in terms of their capability to produce spikes, their responsiveness to excitatory synaptic inputs and their outputs via inhibitory synapses. Importantly, the dysfunction of these active properties appeared severer in alkalosis than acidosis. CONCLUSIONS: The severer impairment of cortical GABAergic neurons in alkalosis patients leads to more critical neural excitotoxicity, so that alkalosis-induced brain dysfunction is difficultly corrected, compared to acidosis. The vulnerability of cortical GABAergic neurons to high pH is likely a basis of severe clinical outcomes in alkalosis versus acidosis.

Overexpression of the long non-coding RNA MEG3 impairs in vitro glioma cell proliferation.

Gliomas are the most common type of primary brain tumor in the central nervous system of adults. Maternally Expressed Gene 3 (MEG3) is an imprinted gene located at 14q32 that encodes a non-coding RNA (ncRNA) associated with tumorigenesis. However, little is known about whether and how MEG3 regulates glioma development. In the present study we assayed the expression of MEG3 in glioma tissue samples by real-time polymerase chain reaction assay, and defined the biological functions and target genes by CCK-8 assay, flow cytometry, and RNA immunoprecipitation. We first demonstrated that MEG3 expression was markedly decreased in glioma tissues compared with adjacent normal tissues. Moreover, ectopic expression of MEG3 inhibited cell proliferation and promoted cell apoptosis in U251 and U87 MG human glioma cell lines. We further verified that MEG3 was associated with p53 and that this association was required for p53 activation. These data suggest an important role of MEG3 in the molecular etiology of glioma and implicate the potential application of MEG3 in glioma therapy.