scholarly journals Metformin Protects Neurons against Oxygen-Glucose Deprivation/Reoxygenation -Induced Injury by Down-Regulating MAD2B

2016 ◽  
Vol 40 (3-4) ◽  
pp. 477-485 ◽  
Author(s):  
Xianfang Meng ◽  
Guangpin Chu ◽  
Zhihua Yang ◽  
Ping Qiu ◽  
Yue Hu ◽  
...  

Background/Aims: Metformin, the common medication for type II diabetes, has protective effects on cerebral ischemia. However, the molecular mechanisms are far from clear. Mitotic arrest deficient 2-like protein 2 (MAD2B), an inhibitor of the anaphase-promoting complex (APC), is widely expressed in hippocampal and cortical neurons and plays an important role in mediating high glucose-induced neurotoxicity. The present study investigated whether metformin modifies the expression of MAD2B and to exert its neuroprotective effects in primary cultured cortical neurons during oxygen-glucose deprivation/reoxygenation (OGD/R), a widely used in vitro model of ischemia/reperfusion. Methods: Primary cortical neurons were cultured, deprived of oxygen-glucose for 1 h, and then recovered with oxygen-glucose for 12 h and 24 h. Cell viability was measured by detecting the levels of lactate dehydrogenase (LDH) in culture medium. The levels of MAD2B, cyclin B and p-histone 3 were measured by Western blot. Results: Cell viability of neurons was reduced under oxygen-glucose deprivation/reoxygenation (OGD/R). The expression of MAD2B was increased under OGD/R. The levels of cyclin B1, which is a substrate of APC, were also increased. Moreover, OGD/R up-regulated the phosphorylation levels of histone 3, which is the induction of aberrant re-entry of post-mitotic neurons. However, pretreatment of neurons with metformin alleviated OGD/R-induced injury. Metformin further decreased the expression of MAD2B, cyclin B1 and phosphorylation levels of histone 3. Conclusion: Metformin exerts its neuroprotective effect through regulating the expression of MAD2B in neurons under OGD/R.

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Hong-yi Qi ◽  
Li Li ◽  
Jie Yu ◽  
Lu Chen ◽  
Yong-liang Huang ◽  
...  

Chinese herbal medicine formula Tao Hong Si Wu decoction (THSWD) is traditionally used in China for cerebrovascular diseases. However, the molecular mechanisms of THSWD associated with the cerebral ischemia reperfusion injury are largely unknown. The current study applied the two-dimensional gel electrophoresis-based proteomics to investigate the different protein profiles in PC12 cells with and without the treatment of THSWD. Twenty-six proteins affected by THSWD were identified by MALDI-TOF mass spectrometry. Gene ontology analysis showed that those proteins participated in several important biological processes and exhibited diverse molecular functions. In particular, six of them were found to be phase II antioxidant enzymes, which were regulated by NF-E2-related factor-2 (Nrf2). Quantitative PCR further confirmed a dose-dependent induction of the six phase II enzymes by THSWD at the transcription level. Moreover, the individual ingredients of THSWD were discovered to synergistically contribute to the induction of phase II enzymes. Importantly, THSWD’s protection against oxygen-glucose deprivation-reperfusion (OGD-Rep) induced cell death was significantly attenuated by antioxidant response element (ARE) decoy oligonucleotides, suggesting the protection of THSWD may be likely regulated at least in part by Nrf2-mediated phase II enzymes. Thus, our data will help to elucidate the molecular mechanisms underlying the neuroprotective effect of THSWD.


2021 ◽  
Vol 23 (3) ◽  
pp. 420-436
Author(s):  
Hyuk Sung Kwon ◽  
Ye Eun Kim ◽  
Hyun-Hee Park ◽  
Jeong-Woo Son ◽  
Hojin Choi ◽  
...  

Background and Purpose Previous studies have revealed the diverse neuroprotective effects of GV1001. In this study, we investigated the effects of GV1001 on focal cerebral ischemia-reperfusion injury (IRI) in rats and oxygen-glucose deprivation/reoxygenation (OGD/R)-induced injury in neural stem cells (NSCs) and cortical neurons. Methods Focal cerebral IRI was induced by transient middle cerebral artery occlusion (MCAO). Brain diffusion-weighted imaging (DWI) was performed 2 hours after occlusion, and a total of 37 rats were treated by reperfusion with GV1001 or saline 2 hours after occlusion. Fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging, immunohistochemistry, and neurobehavioral function analyses were performed. Additionally, OGD/R-injured NSCs and cortical neurons were treated with different GV1001 concentrations. Cell viability, proliferation, migration, and oxidative stress were determined by diverse molecular analyses. Results In the stroke model, GV1001 protected neural cells against IRI. The most effective dose of GV1001 was 60 μM/kg. The infarct volume on FLAIR 48 hours after MCAO compared to lesion volume on DWI showed a significantly smaller ratio in the GV1001-treated group. GV1001-treated rats exhibited better behavioral functions than the saline-treated rats. Treatment with GV1001 increased the viability, proliferation, and migration of the OGD/R-injured NSCs. Free radicals were significantly restored by treatment with GV1001. These neuroprotective effects of GV1001 have also been demonstrated in OGD/R-injured cortical neurons. Conclusions The results suggest that GV1001 has neuroprotective effects against IRI in NSCs, cortical neurons, and the rat brain. These effects are mediated through the induction of cellular proliferation, mitochondrial stabilization, and anti-apoptotic, anti-aging, and antioxidant effects.


2012 ◽  
Vol 82 (4) ◽  
pp. 267-274 ◽  
Author(s):  
Zahide Cavdar ◽  
Mehtap Y. Egrilmez ◽  
Zekiye S. Altun ◽  
Nur Arslan ◽  
Nilgun Yener ◽  
...  

The main pathophysiology in cerebral ischemia is the structural alteration in the neurovascular unit, coinciding with neurovascular matrix degradation. Among the human matrix metalloproteinases (MMPs), MMP-2 and -9, known as gelatinases, are the key enzymes for degrading type IV collagen, which is the major component of the basal membrane that surrounds the cerebral blood vessel. In the present study, we investigated the effects of resveratrol on cytotoxicity, reactive oxygen species (ROS), and gelatinases (MMP-2 and -9) in human cerebral microvascular endothelial cells exposed to 6 hours of oxygen-glucose deprivation and a subsequent 24 hours of reoxygenation with glucose (OGD/R), to mimic ischemia/reperfusion in vivo. Lactate dehydrogenase increased significantly, in comparison to that in the normoxia group. ROS was markedly increased in the OGD/R group, compared to normoxia. Correspondingly, ROS was significantly reduced with 50 μM of resveratrol. The proMMP-2 activity in the OGD/R group showed a statistically significant increase from the control cells. Resveratrol preconditioning decreased significantly the proMMP-2 in the cells exposed to OGD/R in comparison to that in the OGD/R group. Our results indicate that resveratrol regulates MMP-2 activity induced by OGD/R via its antioxidant effect, implying a possible mechanism related to the neuroprotective effect of resveratrol.


2014 ◽  
Vol 4 (1) ◽  
Author(s):  
Xiao-Ya Gao ◽  
Jian-Ou Huang ◽  
Ya-Fang Hu ◽  
Yong Gu ◽  
Shu-Zhen Zhu ◽  
...  

Abstract Co-treatment of neuroprotective reagents may improve the therapeutic efficacy of hypothermia in protecting neurons during ischemic stroke. This study aimed to find promising drugs that enhance the neuroprotective effect of mild hypothermia (MH). 26 candidate drugs were selected based on different targets. Primary cultured cortical neurons were exposed to oxygen-glucose deprivation and reoxygenation (OGD/R) to induce neuronal damage, followed by either single treatment (a drug or MH) or a combination of a drug and MH. Results showed that, compared with single treatment, combination of MH with brain derived neurotrophic factor, glibenclamide, dizocilpine, human urinary kallidinogenase or neuroglobin displayed higher proportion of neuronal cell viability. The latter three drugs also caused less apoptosis rate in combined treatment. Furthermore, co-treatment of those three drugs and MH decreased the level of reactive oxygen species (ROS) and intracellular calcium accumulation, as well as stabilized mitochondrial membrane potential (MMP), indicating the combined neuroprotective effects are probably via inhibiting mitochondrial apoptosis pathway. Taken together, the study suggests that combined treatment with hypothermia and certain neuroprotective reagents provide a better protection against OGD/R-induced neuronal injury.


2016 ◽  
Vol 44 (05) ◽  
pp. 927-941 ◽  
Author(s):  
Qichun Zhang ◽  
Huimin Bian ◽  
Liwei Guo ◽  
Huaxu Zhu

Berberine exerts neuroprotective and modulates hypoxia inducible factor-1-alpha (HIF-1[Formula: see text]. Based on the role of HIF-1[Formula: see text] in hypoxia preconditioning and association between HIF-1[Formula: see text] and sphingosine-1-phosphate (S1P), we hypothesized that berberine preconditioning (BP) would ameliorate the cerebral injury induced by ischemia through activating the system of HIF-1[Formula: see text] and S1P. Adult male rats with middle cerebral artery occlusion (MCAO) and rat primary cortical neurons treated with oxygen and glucose deprivation (OGD) with BP at 24[Formula: see text]h (40[Formula: see text]mg/kg) and 2[Formula: see text]h (10[Formula: see text][Formula: see text]mol/L), respectively, were used to determine the neuroprotective effects. The HIF-1[Formula: see text] accumulation, and S1P metabolism were assayed in the berberine-preconditioned neurons, and the HIF-1[Formula: see text]-mediated transcriptional modulation of sphingosine kinases (Sphk) 1 and 2 was analyzed using chromatin immunoprecipitation and real-time polymerase chain reaction. BP significantly prevented cerebral ischemic injury in the MCAO rats at 24[Formula: see text]h and 72[Formula: see text]h following ischemia/reperfusion. In OGD-treated neurons, BP enhanced HIF-1[Formula: see text] accumulation with activation of PI3K/Akt, and induced S1P production by activating Sphk2 via the promotion of HIF-1[Formula: see text]-mediated Sphk2 transcription. In conclusion, BP activated endogenous neuroprotective mechanisms associated with the S1P/HIF-1 pathway and helped protect neuronal cells against hypoxia/ischemia.


2017 ◽  
Vol 127 (1) ◽  
pp. 98-110 ◽  
Author(s):  
Qian Zhai ◽  
Feng Li ◽  
Xiyao Chen ◽  
Ji Jia ◽  
Sisi Sun ◽  
...  

Abstract Background Microglia can not only detrimentally augment secondary injury but also potentially promote recovery. However, the mechanism underlying the regulation of microglial phenotypes after stroke remains unclear. Methods Mice were subjected to middle cerebral artery occlusion for 60 min. At 3 days after reperfusion, the effects of activation and suppression of triggering receptor expressed on myeloid cells 2 on immunocyte phenotypes (n = 5), neurobehavioral scores (n = 7), infarct volumes (n = 8), and neuronal apoptosis (n = 7) were analyzed. In vitro, cultured microglia were exposed to oxygen–glucose deprivation for 4 h. Inflammatory cytokines, cellular viability (n = 8), neuronal apoptosis (n = 7), and triggering receptor expressed on myeloid cells 2 expression (n = 5) were evaluated in the presence or absence of triggering receptor expressed on myeloid cell-specific small interfering RNA or triggering receptor expressed on myeloid cells 2 overexpression lentivirus. Results Triggering receptor expressed on myeloid cells 2 expression in the ischemic penumbra peaked at 3 days after ischemia–reperfusion injury (4.4 ± 0.1-fold, P = 0.0004) and was enhanced in interleukin-4/interleukin-13–treated microglia in vitro (1.7 ± 0.2-fold, P = 0.0119). After oxygen–glucose deprivation, triggering receptor expressed on myeloid cells 2 conferred neuroprotection by regulating the phenotypic conversion of microglia and inflammatory cytokine release. Intraperitoneal administration of triggering receptor expressed on myeloid cells 2 agonist heat shock protein 60 or unilateral delivery of a recombinant triggering receptor expressed on myeloid cells 2 lentivirus into the cerebral ventricle induced a significant neuroprotective effect in mice (apoptotic neurons decreased to 31.3 ± 7.6%; infarct volume decreased to 44.9 ± 5.3%). All values are presented as the mean ± SD. Conclusions Activation or up-regulation of triggering receptor expressed on myeloid cells 2 promoted the phenotypic conversion of microglia and decreased the number of apoptotic neurons. Our study suggests that triggering receptor expressed on myeloid cells 2 is a novel regulator of microglial phenotypes and may be a potential therapeutic target for stroke.


2021 ◽  
Vol 18 (10) ◽  
pp. 2037-2043
Author(s):  
Hong Zhu ◽  
Dan Ren ◽  
Lan Xiao ◽  
Ting Zhang ◽  
Ruomeng Li ◽  
...  

Purpose: To investigate whether the cytoprotective effect of anthocyanin (Anc) on oxygen-glucose deprivation/reperfusion (OGD/R)-induced cell injury is related to apoptosis signal-regulating kinase 1 (ASK1)/c-Jun N-terminal kinase (JNK)/p38 signaling pathway. Methods: PC12 cells were pre-treated with various concentrations of Anc (10, 50, and 100 μg/mL) in OGD/R-induced cell injury model. The 3-(4, 5)-dimethylthiahiazo (-z-y1)-3, 5-di-phenytetrazoliumromide (MTT) assay was used to assess cell viability. Cell apoptosis was measured by lactic acid dehydrogenase (LDH) release assay and flow cytometry. Western blot was employed to determine the protein expressions of BCL-2, BAX, caspase-3, p-ASK1 (Thr845), p-JNK, and p-p38. Results: The results indicate that Anc increased the viability of PC12 cells after OGD/R exposure (p < 0.05), and also efficiently rescued OGD/R-induced apoptosis (p < 0.05). Mechanistic studies showed that these protective roles of Anc are related to the inhibition of ASK1/JNK/p38 signaling pathway. Conclusion: The results indicate Anc protects against OGD/R-induced cell injury by enhancing cell viability and inhibiting cell apoptosis. The underlying mechanism of action is partly via inactivation of ASK1/JNK/p38 signaling pathway. Thus, Anc has promise as a potential natural agent to prevent and treat cerebral ischemia-reperfusion injury.


2020 ◽  
Author(s):  
Mingmin Huang ◽  
Shaoru Chen ◽  
Kening Zheng ◽  
Qu Liu ◽  
Kening Li ◽  
...  

Abstract Background: Ginsenoside Rc (Rc) is one of the major active components of Panax ginseng Meyer. Studies have shown that Rc has remarkable effect in protection of nervous system. However, the potential molecular mechanism of its neuroprotective effect remains unclear. Our study aim to investigate the neuroprotective effect of Rc on neuron damage and explore the potential mechanism on its regulation of TNF-α and DRP-1.Methods: Oxygen-glucose deprivation reperfusion (OGD/R) cell neuron damage modle was induced by Na2S2O4 and EBSS solution. After preventive administration, cell viability and cell toxicity were detected to evaluate the putative neuroprotective properties of Rc. Network pharmacology and molecular docking simulation studies were performed to predict the potential targets and pharmacological mechanism. Furthermore, the prediction was validated via western blot assay and specific antagonist. Results: In OGD/R injured cells, Rc significantly improved cell viability (Rc middle dose vs. OGD/R model: 67.3±2.33% vs. 55.7±1.14%, P<0.05) and obviously decreased cell toxicity (Rc middle dose vs. OGD/R model: 147±39.7% vs. 232±29.4%, P<0.01). Analysis of network pharmacology and molecular docking indicated that the key targets of Rc are TNF-α and DRP-1. Subsequently molecular biological studies showed a significant increase on expression of TNF-α and DRP-1 in model group. Conversely, administration of Rc reversed the alteration significantly and presented a dose dependence. By adding antagonist, we validated that Rc had an indirect regulation on TNF-α and DRP-1. Conclusions: Rc possess protective properties against OGD-induced neuron damage by regulating the expression of TNF-α and DRP-1.


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