Weijie Wang

The effect of resveratrol on beta amyloid-induced memory impairment involves inhibition of phosphodiesterase-4 related signaling

Resveratrol, a natural polyphenol found in red wine, has wide spectrum of pharmacological properties including antioxidative and antiaging activities. Beta amyloid peptides (Aβ) are known to involve cognitive impairment, neuroinflammatory and apoptotic processes in Alzheimers disease (AD). Activation of cAMP and/or cGMP activities can improve memory performance and decrease the neuroinflammation and apoptosis. However, it remains unknown whether the memory enhancing effect of resveratrol on AD associated cognitive disorders is related to the inhibition of phosphodiesterase 4 (PDE4) subtypes and subsequent increases in intracellular cAMP and/or cGMP activities. This study investigated the effect of resveratrol on Aβ1-42-induced cognitive impairment and the participation of PDE4 subtypes related cAMP or cGMP signaling. Mice microinfused with Aβ1-42 into bilateral CA1 subregions displayed learning and memory impairment, as evidenced by reduced memory acquisition and retrieval in the water maze and retention in the passive avoidance tasks; it was also significant that neuroinflammatory and pro-apoptotic factors were increased in Aβ1-42-treated mice. Aβ1-42-treated mice also increased in PDE4A, 4B and 4D expression, and decreased in PKA level. However, PKA inhibitor H89, but not PKG inhibitor KT5823, prevented resveratrols effects on these parameters. Resveratrol also reversed Aβ1-42-induced decreases in phosphorylated cAMP response-element binding protein (pCREB), brain derived neurotrophic factor (BDNF) and anti-apoptotic factor BCl-2 expression, which were reversed by H89. These findings suggest that resveratrol reversing Aβ-induced learning and memory disorder may involve the regulation of neuronal inflammation and apoptosis via PDE4 subtypes related cAMP-CREB-BDNF signaling.

Resveratrol-induced antinociception is involved in calcium channels and calcium/caffeine-sensitive pools

Resveratrol has been widely investigated for its potential health properties, although little is known about its mechanism in vivo. Previous studies have indicated that resveratrol produces antinociceptive effects in mice. Calcium channels and calcium/caffeine-sensitive pools are reported to be associated with analgesic effect. The present study was to explore the involvement of Ca2+ channel and calcium/caffeine-sensitive pools in the antinociceptive response of resveratrol. Tail-flick test was used to assess antinociception in mice treated with resveratrol or the combinations of resveratrol with MK 801, nimodipine, CaCl2, ryanodine and ethylene glycol tetraacetic acid (EGTA), respectively. The Ca2+/calmodulin-dependent protein kinase II (CaMKII) and brain-derived neurotrophic factor (BDNF) levels in the spinal cord were also investigated when treated with the above drugs. The results showed that resveratrol increased the tail flick latency in the tail-flick test, in dose-dependent manner. N-methyl-D-aspartate (NMDA) glutamate receptor antagonist MK 801 potentiated the antinociceptive effects of sub-threshold dose of resveratrol at 10 mg/kg. Ca2+ channel blocker, however, abolished the antinociceptive effects of resveratrol. In contrast to these results, EGTA or ryanodine treatment (i.c.v.) potentiated resveratrol-induced antinociception. There was a significant decrease in p-CaMKII and an increase in BDNF expression in the spinal cord when combined with MK 801, nimodipine, ryanodine and EGTA. While an increase in p-CaMKII level and a decrease in BDNF expression were observed when high dose of resveratrol combined with CaCl2. These findings suggest that resveratrol exhibits the antinociceptive effects by inhibition of calcium channels and calcium/caffeine-sensitive pools.

Attention dysfunction of postoperative patients with glioma

BackgroundAttention dysfunction has been observed among many kinds of nervous system diseases, including glioma. This study aimed to investigate the correlation between glioma localization, malignancy, postoperative recovery time and attention deficit.MethodsA total of 45 patients with glioma who underwent surgical resection and 18 healthy volunteers were enrolled. The attention network test, digital span test, color trail test II and Stroop test were used to detect the characteristics of attention deficit.ResultsOrientation network dysfunction was detected in the parietal lobe tumor group, and execution network deficit was detected in both the frontal and parietal lobe groups, while no significant difference was detected in the temporal lobe group compared to healthy controls. The high-grade glioma group (grade III-IV) exhibited more serious functional impairment than the low-grade group (grade I-II). No significant correlation was observed between postoperative recovery time and attention impairment.ConclusionsHigh-grade glioma patients suffer more severe attention impairment. In addition, the frontal and parietal lobe glioma patients suffer attention dysfunction in dissimilar manner. These findings will provide important guidance on the care of glioma patients after therapy.

Mir-758-5p Suppresses Glioblastoma Proliferation, Migration and Invasion by Targeting ZBTB20

Background/Aims: To determine the cellular functions and clinical significance of micro-758-5p (miR-758-5p) in glioblastoma (GBM) by targeting zinc finger and BTB domain-containing protein 20 (ZBTB20). Methods: Fifty-five paired GBM tissues and adjacent normal tissues, GBM cell lines (U118, LN-299, H4, A172, U87-MG, and U251), and normal human astrocyte cell line (HEB) were used. miR-758-5p mimics, ZBTB20 siRNA, and pcDNA3.1-ZBTB20 were transiently transduced into cancer cells independently or together. qRT-PCR was conducted to analyze the expression of miR-758-5p and ZBTB20. Luciferase reporter assays were performed to determine the effect of miR-758-5p on ZBTB20. Western blot was applied to measure the expression of ZBTB20, PCNA, and cleaved caspase3. Cell Counting Kit-8 (CCK8), colony formation, FACS, and Transwell assays were carried out to detect cellular proliferation, apoptosis, migration, and invasion. Xenograft experiments were implemented to evaluate tumor growth and metastasis in vivo. Results: miR-758-5p was significantly downregulated in GBM tissues and cell lines compared with that in adjacent normal tissues and HEB cells. miR-758-5p overexpression inhibited the proliferation, migration, and invasion of GBM cells and induced apoptosis by regulating the ZBTB20 expression. Pearson correlation analysis also confirmed that miR-758-5p was inversely correlated with ZBTB20 in GBM tissues. miR-758-5p suppressed tumor growth and metastasis in vivo. The restored ZBTB20 expression partially rescued the miR-758-5p-induced inhibition of GBM cell proliferation, migration, and invasion. Kaplan–Meier curve analysis revealed that a high miR-758-5p expression indicated an enhanced prognosis of patients with GBM. Conclusion: miR-758-5p suppressed GBM progression by targeting ZBTB20. The miR-758-5p/ZBTB20 axis might be a promising therapeutic target for GBM treatment.

Aminoguanidine reverses cognitive deficits and activation of cAMP/CREB/BDNF pathway in mouse hippocampus after traumatic brain injury (TBI)

ABSTRACT Primary Objective: We aim to study the effects of chronic aminoguanidine (AG) administration on learning and memory impairment after TBI and explore the potential mechanism involved in this process. Research Design: Male C57BL/6J mice were divided into 6 groups: Control, TBI + Veh, TBI+ AG (50, 100, 200 and 400 mg/kg, i.p.). Methods and Procedures: Then, we measured cyclicadenosine 3ʹ, 5ʹ-monophosphate (cAMP) content, phosphorylated form of cAMP-response element binding protein (p-CREB) level, iNOS, brain-derived neurotrophic factor (BDNF) and postsynaptic density-93/95 (PSD-93/95) expression in hippocampus. The learning and memory abilities were assessed using Morris water maze and step-down test. Main Outcomes and Results: The results demonstrate that TBI induced down-regulation of BDNF, loss of PSD-93/95, learning and memory deficits with down-regulation of cAMP content and p-CREB/CREB ratio. Administration of AG (200 and 400 mg/kg) reversed TBI induced down-regulation of BDNF and PSD-93/95, up-regulated the cAMP content and p-CREB/CREB ratio, which resulted in improvement of learning and memory ability. Conclusions: We suspect that AG (200 and 400 mg/kg) might reverse TBI-induced selective loss of postsynaptic proteins and learning and memory deficits with the activation of cAMP/CREB/BDNF signalling pathway.

The analgesic effect of trans-resveratrol is regulated by calcium channels in the hippocampus of mice

Resveratrol has been widely studied in terms of it’s potential to slow the progression of many diseases. But little is known about the mechanism of action in neuropathic pain. Neuropathic pain is the main type of chronic pain associated with tissue injury. Calcium channels and calcium/caffeine-sensitive pools are associated with analgesic pathway involving neuropathic pain. Our previous study suggested that the antinociceptive effect of resveratrol was involved in Ca2+/calmodulin-dependent signaling in the spinal cord of mice. The aim of this study was to explore the involvement of Ca2+ in analgesic effects of trans-resveratrol in neuropathic pain and signal pathway in hippocampus. Hot plate test was used to assess antinociceptive response when mice were treated with trans-resveratrol alone or in combination with Mk 801, nimodipine, CaCl2, ryanodine or EGTA. The effects of trans-resveratrol and the combination on Ca2+/calmodulin-dependent protein kinase II (CaMKII) and BDNF (brain-derived neurotrophic factor) expression in hippocampus were also investigated. The results showed that trans-resveratrol increased paw withdraw latency in the hot plate test. The effect of resveratrol was enhanced by Mk 801 and nimodipine. Central administration of Ca2+, however, abolished the antinociceptive effects of resveratrol. In contrast, centrally administered EGTA or ryanodine improved trans-resveratrol induced antinociception. There was a significant increase in p-CaMKII and BDNF expression in the hippocampus when resveratrol were combined with Mk 801, nimodipine, ryanodine and EGTA. Administration of CaCl2 blocked changes in p-CaMKII and BDNF levels in the hippocampus. These findings suggest that trans-resveratrol exerts the effects of antinociception through regulation of calcium channels and calcium/caffeine-sensitive pools.

Apollon overexpression promotes cell motility of gliomas, and predicts patients’ poor prognosis

Background: Apollon has been reported to play an oncogenic role in various human cancers. Glioma cell line SNB-78 has been reported to express an increased level of apollon and had distinct resistance against several anti-cancer drugs. Here, we aimed to investigate the clinical impact of apollon dysregulation in patients with gliomas, and its functions in malignant phenotypes of glioma cells. Methods: Apollon expression in human gliomas tissues was examined by immunohistochemistry. Associations between apollon expression and various clinicopathological factors as well as patients’ prognosis were then evaluated. Followed by the transfection of an apollon-specific small interfering RNA in glioma cells, cell migration and invasion were measured by transwell assays in vitro . Results: Immunostainings of apollon protein were mainly shown in tumor cell cytoplasm of glioma tissues, but weakly or negatively observed in nonneoplastic brain tissues. Statistically, the immunoreactive score (IRS) of apollon protein in glioma tissues was significantly higher than that in the corresponding nonneoplastic brain tissues (P=0.013). Additionally, patients with higher IRS often had advanced World Health Organization (WHO) grade (P=0.001) and shorter overall survival time (P=0.01). Further multivariate analysis identified apollon expression as an independent prognostic factor of glioma patients (P=0.03). Functionally, in vitro experiments revealed that loss of apollon could efficiently suppress migration and invasion of glioma cells. Conclusions: These findings imply that the dysregulation of apollon may be implicated into tumorigenesis and various pathological changes of human gliomas. Importantly, this protein might be a potential prognostic marker and novel therapeutic target for patients with this tumor.