scholarly journals Dexmedetomidine Protects Neural Stem Cells from Ketamine-Induced Injury

2018 ◽  
Vol 47 (4) ◽  
pp. 1377-1388 ◽  
Author(s):  
Pan Lu ◽  
Shan Lei ◽  
Weisong Li ◽  
Yang Lu ◽  
Juan Zheng ◽  
...  

Background/Aims: Ketamine inhibits the proliferation of neural stem cells (NSCs) and disturbs normal neurogenesis. Dexmedetomidine provides neuroprotection against volatile anesthetic-induced neuroapoptosis and cognitive impairment in the developing brain. Whether it may protect NSCs from ketamine-induced injury remains unknown. In this study, we investigated the protective effects of dexmedetomidine on ketamine-exposed NSCs and explored the mechanisms potentially involved. Methods: Primary NSC cultures were characterized using immunofluorescence. Cell viability was determined using a Cell Counting Kit 8 assay. Proliferation and apoptosis were assessed with BrdU incorporation and TUNEL assays, respectively. Protein levels of cleaved caspase-3, phosphorylated protein kinase B (p-Akt), and glycogen synthase kinase-3β (p-GSK-3β) were quantified using western blotting. Results: Ket-amine significantly decreased NSC viability and proliferation and increased their apoptosis. Dexmedetomidine increased NSC proliferation and decreased their apoptosis in a dose-dependent manner. Furthermore, dexmedetomidine pretreatment notably augmented the viability and proliferation of ketamine-exposed NSCs and reduced their apoptosis. Moreover, dexmedetomidine lessened caspase-3 activation and increased p-Akt and p-GSK-3β levels in NSCs exposed to ketamine. The protective effects of dexmedetomidine on ketamine-exposed NSCs could be partly reversed by the PI3K inhibitor LY294002. Conclusions: Collectively, these findings indicate that dexmedetomidine may protect NSCs from ketamine-induced injury via the PI3K/Akt/GSK-3β signaling pathway.

2017 ◽  
Vol 43 (4) ◽  
pp. 1547-1561 ◽  
Author(s):  
Chun Guo ◽  
Rui-Juan Yang ◽  
Ke Jang ◽  
Xiao-ling Zhou ◽  
Yu-zhen Liu

Background/Aims: Quercetin, a flavonoid found in onions and other vegetables, has potential inhibitory effects on bone resorption in vivo and in vitro. In our previous study, we found that quercetin treatment reversed lipopolysaccharide (LPS)-induced inhibition of osteoblast differentiation through the mitogen-activated protein kinase (MAPK) pathway in MC3T3-E1 cells. In this study, we investigated the underlying mechanisms of pretreatment with quercetin on apoptosis and the inhibition of osteoblast differentiation in MC3T3-E1 cells induced by LPS. Methods: MC3T3-E1 osteoblasts were treated with quercetin for 2 h; cells were then incubated with LPS in the presence of quercetin for the indicated times. Cell viability was measured using the Cell Counting Kit-8 (CCK-8) assay, and cell apoptosis was evaluated using Hoechst 33258 staining. The mRNA expression levels of osteoblast-specific genes, Bax and caspase-3 were determined by real-time quantitative polymerase chain reaction (qPCR). Protein levels of osteoblast-specific genes, caspase-3, Bax, cytochrome c, Bcl-2, Bcl-XL, phosphorylated MAPKs and Wnt/β-catenin were measured using Western blot assays. The MAPK and Wnt/β-catenin signalling pathways were blocked prior to pretreatment with quercetin. Results: Pretreatment with quercetin significantly restored LPS-suppressed bone mineralization and the mRNA and protein expression levels of osteoblast-specific genes such as Osterix (OSX), runt-related transcription factor 2 (Runx2), alkaline phosphatase (ALP) and osteocalcin (OCN) in a dose-dependent manner. Pretreatment with quercetin also inhibited osteoblast apoptosis, significantly restored the down-regulated expression of Bcl-2 and Bcl-XL and decreased the upregulated expression of caspase-3, Bax, and cytochrome c in MC3T3-E1 cells induced by LPS. Furthermore, pretreatment with quercetin not only decreased the abundance of phosphorylated p38 MAPK and increased the abundance of phosphorylated extracellular signal regulated kinase (ERK), but also triggered the Wnt/β-catenin pathway through enhancing expression of Wnt3 and β-catenin. Pretreatment with MAPK inhibitors or the Wnt/β-catenin inhibitor XAV939 blocked the protective effects of quercetin against LPS-induced apoptosis and the inhibition of osteoblast differentiation. Conclusions: Our findings suggest that pretreatment with quercetin may be a potential drug for preventing abnormal human bone loss induced by LPS in bacteria-induced bone diseases.


2021 ◽  
Vol 12 ◽  
Author(s):  
Liping Cao ◽  
Zhenghong Li ◽  
Yi Ren ◽  
Mengmeng Wang ◽  
Zhizhou Yang ◽  
...  

Xuebijing (XBJ), the only drug approved for the sepsis and multiple organ dysfunction, and its protective effects against acute liver injury (ALI) and its mechanism. The aim of this study was to evaluate the protective effect of XBJ on cecal ligation and perforation (CLP)-induced mouse ALI model and LPS-induced RAW264.7 cell ALI model. Mice were pretreated with XBJ before the CLP model was established, and serum and liver tissues were collected at the end of the experiment to assess the levels of inflammatory factors and liver injury. Results showed that XBJ pretreatment reduced liver/body weight, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities in serum, and inhibited levels of pro-inflammatory factors in serum. Cells were treatment with XBJ and modeled by LPS modeling increased cell viability in the XBJ-treated group compared to the model group and XBJ also decreased serum pro-inflammatory factors in a dose-dependent manner. Western blot detected that XBJ also up-regulated the phosphorylated levels of glycogen synthase kinase-3β (p-GSK-3β) and cAMP-response element-binding protein (p-CREB) and down-regulated the phosphorylated level of nuclear factor kappa-B (p-NF-κB) in liver and cell. After overexpression of GSK-3β in cells, the mechanism was further investigated using CO-IP analysis. The binding of p-NF-κB and p-CREB to CREB-binding protein (CBP) was increased and decreased, respectively, indicating that GSK-3β regulated inflammation by regulating the binding of p-NF-κB and p-CREB to CBP. The present studies suggested that the hepatoprotective effect of XBJ may be through up-regulation of GSK-3β (Ser9) and increasing the binding of p-CREB to CBP, thereby alleviating the inflammatory response.


2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Qunwen Pan ◽  
Yan Wang ◽  
Qing Lan ◽  
Weiquan Wu ◽  
Zhenxuan Li ◽  
...  

Mesenchymal stem cells (MSCs) show protective effects on ischemia/reperfusion- (I/R-) induced endothelial cell (EC) injury and vascular damage. Stem cell-released exosomes (EXs) could modulate target cell functions by delivering their cargos, and exert therapeutic effects as their mother cells. miR-126 is an important regulator of EC functions and angiogenesis. In this study, we determined whether EXs released from MSC-EXs provided beneficial effects on hypoxia/reoxygenation- (H/R-) injured ECs by transferring miR-126. MSCs were transfected with a miR-126 mimic or miR-126 short hairpin RNA to obtain miR-126-overexpressing MSC-EXs (MSC-EXsmiR-126) and miR-126 knockdown MSC-EXs (MSC-EXsSimiR-126). For functional studies, H/R-injured ECs were coincubated with various MSC-EXs. The viability, migration, tube formation ability, and apoptosis of ECs were measured. miR-126 and proangiogenic/growth factor (VEGF, EGF, PDGF, and bFGF) expressions were detected by qRT-PCR. Akt, p-Akt, p-eNOS, and cleaved caspase-3 expressions were examined by western blot. The PI3K inhibitor (LY294002) was used in pathway analysis. We found that overexpression/knockdown of miR-126 increased/decreased the proliferation of MSCs, as well as miR-126 expression in their derived MSC-EXs. MSC-EXsmiR-126 were more effective in promoting proliferation, migration, and tube formation ability of H/R-injured ECs than MSC-EXs. These effects were associated with the increase in p-Akt/Akt and p-eNOS, which could be abolished by LY294002. Besides, MSC-EXsmiR-126 were more effective than MSC-EXs in reducing the apoptosis of ECs, coupled with the decrease in cleaved caspase-3. Moreover, compared to MSC-EXs, MSC-EXsmiR-126 significantly upregulated the level of VEGF, EGF, PDGF, and bFGF in H/R-injured ECs. Downregulation of miR-126 in MSC-EXs inhibited these effects of MSC-EXs. The results suggest that MSC-EXs could enhance the survival and angiogenic function of H/R-injured ECs via delivering miR-126 to ECs and subsequently activate the PI3K/Akt/eNOS pathway, decrease cleaved caspase-3 expression, and increase angiogenic and growth factors.


2021 ◽  
Vol 12 ◽  
Author(s):  
Shiqing Zhang ◽  
Xiaoli Jiang ◽  
Ying Wang ◽  
Kaili Lin ◽  
Zhang Zhang ◽  
...  

An-Gong-Niu-Huang Wan (AGNHW), a famous formula in traditional Chinese medicine, has been clinically used for centuries for treating cerebral diseases, but the protective effects of pre-treatment with AGNHW on cerebral ischemia have not yet been reported. The present study aimed to test such protective effects and elucidate the underlying mechanisms on cerebral ischemia in rats by phenotypic approaches (i.e. including the neurological functional score, cerebral infarct area, neuron apoptosis, and brain oxidative stress status) and target-based approaches (i.e. involving the GSK-3β/HO-1 pathway). AGNHW was administered orally at the doses of 386.26, 772.52, and 1545.04 mg/kg respectively for 7 days to male Sprague-Dawley rats and then cerebral ischemia was induced by middle cerebral artery occlusion (MCAO) for 1.5 h. Pre-treatment with AGNHW significantly ameliorated ischemic damage to the brain in a dose-dependent manner, including reduction of the neurological deficit score and infarct area. AGNHW pre-treatment increased the number of Nissl+ cells, NeuN+ and DCX+ cells, and decreased the number of Tunel+ cells. Moreover, AGNHW reversed the up-regulation of ROS and MDA induced by cerebral ischemia. AGNHW pre-treatment increased the expression of p-GSK-3β(Ser9)/GSK-3β (glycogen synthase kinase-3β) ratio and heme oxygenase-1 (HO-1). These results firstly revealed that short-term pre-treatment of AGNHW could significantly protect the rats from injury caused by cerebral ischemia-reperfusion, which support further clinical studies for disease prevention. The in vivo protective effect of AGNWH pre-treatment could be associated with its antioxidant properties by the activation of GSK-3β-mediated HO-1 pathway.


2013 ◽  
Vol 218 (1) ◽  
pp. 49-59 ◽  
Author(s):  
Hyunju Chung ◽  
Endan Li ◽  
Yumi Kim ◽  
Sehee Kim ◽  
Seungjoon Park

Ghrelin, an endogenous ligand for the GH secretagogue receptor (GHS-R) receptor 1a (GHS-R1a), has been implicated in several physiologic processes involving the hippocampus. The aim of this study was to investigate the molecular mechanisms of ghrelin-stimulated neurogenesis using cultured adult rat hippocampal neural stem cells (NSCs). The expression of GHS-R1a was detected in hippocampal NSCs, as assessed by western blot analysis and immunocytochemistry. Ghrelin treatment increased the proliferation of cultured hippocampal NSCs assessed by BrdU incorporation. The exposure of cells to the receptor-specific antagonist d-Lys-3-GHRP-6 abolished the proliferative effect of ghrelin. By contrast, ghrelin showed no significant effect on cell differentiation. The expression of GHS-R1a was significantly increased by ghrelin treatment. The analysis of signaling pathways showed that ghrelin caused rapid activation of ERK1/2 and Akt, which were blocked by the GHS-R1a antagonist. In addition, ghrelin stimulated the phosphorylation of Akt downstream effectors, such as glycogen synthase kinase (GSK)-3β, mammalian target of rapamycin (mTOR), and p70S6K. The activation of STAT3 was also caused by ghrelin treatment. Furthermore, pretreatment of cells with specific inhibitors of MEK/ERK1/2, phosphatidylinositol-3-kinase (PI3K)/Akt, mTOR, and Jak2/STAT3 attenuated ghrelin-induced cell proliferation. Taken together, our results support a role for ghrelin in adult hippocampal neurogenesis and suggest the involvement of the ERK1/2, PI3K/Akt, and STAT3 signaling pathways in the mediation of the actions of ghrelin on neurogenesis. Our data also suggest that PI3K/Akt-mediated inactivation of GSK-3β and activation of mTOR/p70S6K contribute to the proliferative effect of ghrelin.


Author(s):  
Merve Erkisa ◽  
Nazlihan Aztopal ◽  
Elif Erturk ◽  
Engin Ulukaya ◽  
Veysel T. Yilmaz ◽  
...  

Background: Cancer stem cells (CSC) are subpopulation within the tumor that acts a part in the initiation, progression, recurrence, resistance to drugs and metastasis of cancer. It is well known that epigenetic changes lead to tumor formation in cancer stem cells and show drug resistance. Epigenetic modulators and /or their combination with different agents have been used in cancer therapy. Objective: In our study we scope out the effects of combination of a histone deacetylases inhibitor, valproic acid (VPA), and Cu(II) complex [Cu(barb-κN)(barb-κ2N,O)(phen-κN,N’)]·H2O] on cytotoxicity/apoptosis in a stem-cell enriched population (MCF-7s) obtained from parental breast cancer cell line (MCF-7). Methods: Viability of the cells was measured by the ATP assay. Apoptosis was elucidated via the assessment of caspase-cleaved cytokeratin 18 (M30 ELISA) and a group of flow cytometry analysis (caspase 3/7 activity, phosphatidylserine translocation by annexin V-FITC assay, DNA damage and oxidative stress) and 2ˈ,7ˈ–dichlorofluorescein diacetate staining. Results: The VPA combined with Cu(II) complex showed anti proliferative activity on MCF-7s cells in a dose- and time-dependently. Treatment with combination of 2.5 mM VPA and 3.12 μM Cu(II) complex induces oxidative stress in a time-dependent manner, as well as apoptosis that is evidenced by the increase in caspase 3/7 activity, positive annexin-V-FITC, and increase in M30 levels. Conclusion: The results suggest that the combination therapy induces apoptosis following increased oxidative stress, thereby making it a possible promising therapeutic strategy that further analysis is required.


Biomolecules ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 181 ◽  
Author(s):  
Wang Liao ◽  
Yuqiu Zheng ◽  
Wenli Fang ◽  
Shaowei Liao ◽  
Ying Xiong ◽  
...  

Alzheimer’s disease (AD) is a devastating neurodegenerative disease with limited treatment options and no cure. Beta-amyloid (Aβ) is a hallmark of AD that has potent neurotoxicity in neural stem cells (NSCs). Dual specificity phosphatase 6 (DUSP6) is a member of the mitogen-activated protein kinases (MAPKs), which is involved in regulating various physiological and pathological processes. Whether DUSP6 has a protective effect on Aβ-induced NSC injury remains to be explored. C17.2 neural stem cells were transfected with DUSP6-overexpressed plasmid. NSCs with or without DUSP6 overexpression were administrated with Aβ25–35 at various concentrations (i.e., 0, 2.5, 5 μM). DUSP6 expression after Aβ treatment was detected by Real-Time Polymerase Chain Reaction (RT-PCR) and Western blot and cell vitality was examined by the CCK8 assay. The oxidative stress (intracellular reactive oxygen species (ROS) and malondialdehyde (MDA)), endoplasmic reticulum stress (ER calcium level) and mitochondrial dysfunction (cytochrome c homeostasis) were tested. The expression of p-ERK1/2 and ERK1/2 were assayed by Western blot. Our results showed that Aβ decreased the expression of DUSP6 in a dose-dependent manner. The overexpression of DUSP6 increased the cell vitality of NSCs after Aβ treatment. Oxidative stress, ER stress, and mitochondrial dysfunction induced by Aβ could be restored by DUSP6 overexpression. Additionally, the Aβ-induced ERK1/2 activation was reversed. In summary, DUSP6 might have a neuroprotective effect on Aβ-induced cytotoxicity, probably via ERK1/2 activation.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 2309-2309
Author(s):  
Jian Huang ◽  
Peter S. Klein

Abstract Abstract 2309 Hematopoietic stem cells (HSCs) maintain the ability to self-renew and to differentiate into all lineages of the blood. The signaling pathways regulating hematopoietic stem cell (HSCs) self-renewal and differentiation are not well understood. We are very interested in understanding the roles of glycogen synthase kinase-3 (Gsk3) and the signaling pathways regulated by Gsk3 in HSCs. In our previous study (Journal of Clinical Investigation, December 2009) using loss of function approaches (inhibitors, RNAi, and knockout) in mice, we found that Gsk3 plays a pivotal role in controlling the decision between self-renewal and differentiation of HSCs. Disruption of Gsk3 in bone marrow transiently expands HSCs in a b-catenin dependent manner, consistent with a role for Wnt signaling. However, in long-term repopulation assays, disruption of Gsk3 progressively depletes HSCs through activation of mTOR. This long-term HSC depletion is prevented by mTOR inhibition and exacerbated by b-catenin knockout. Thus GSK3 regulates both Wnt and mTOR signaling in HSCs, with opposing effects on HSC self-renewal such that inhibition of Gsk3 in the presence of rapamycin expands the HSC pool in vivo. In the current study, we found that suppression of the mammalian target of rapamycin (mTOR) pathway, an established nutrient sensor, combined with activation of canonical Wnt/ß-catenin signaling, allows the ex vivo maintenance of human and mouse long-term HSCs under cytokine-free conditions. We also show that combining two clinically approved medications that activate Wnt/ß-catenin signaling and inhibit mTOR increases the number of long-term HSCs in vivo. Disclosures: No relevant conflicts of interest to declare.


2020 ◽  
Author(s):  
Huanhuan Sha ◽  
Peipei Peng ◽  
Bing Li ◽  
Guohua Wei ◽  
Juan Wang ◽  
...  

Abstract Background: Recently, the number of neonatal patients receiving surgery under general anesthesia has increased. Ketamine disrupts the proliferation and differentiation of developing neural stem cells (NSCs). Therefore, the safe use of ketamine in pediatric anesthesia has been an issue of increasing concern among anesthesiologists and the children’s parents. Dexmedetomidine (DEX) is widely used in sedation, as an antianxiety agent and for analgesia. DEX has recently been shown to provide neuroprotection against anesthetic-induced neurotoxicity in the developing brain. The aim of this in vivo study was to investigate whether DEX exerted neuroprotective effects on the proliferation and differentiation of NSCs in the subventricular zone (SVZ) following neonatal ketamine exposure. Methods: Postnatal day 7 (PND-7) male Sprague-Dawley rats were equally divided into the following 5 groups: Control group (n=8), Ketamine group (n=8), 1 μg/kg DEX+Ketamine group (n=8), 5 μg/kg DEX+Ketamine group (n=8) and 10 μg/kg DEX+Ketamine group (n=8). The proliferation and differentiation of NSCs in the SVZ were assessed using immunostaining with BrdU incorporation. The levels of Nestin and β-tubulin III in the SVZ were measured using Western blot analyses. Apoptosis was assessed by detecting the levels of the cleaved caspase-3 protein using Western blotting. Results: Neonatal ketamine exposure significantly inhibited NSC proliferation and astrocytic differentiation in the SVZ, and neuronal differentiation was markedly increased. Furthermore, pretreatment with moderate (5 μg/kg) or high doses (10 μg/kg) of DEX reversed the ketamine-induced disturbances in the proliferation and differentiation of NSCs. Meanwhile, neonatal ketamine exposure significantly decreased the expression of Nestin and increased the expression of β-tubulin III in the SVZ compared with the Control group. Treatment with 10 μg/kg DEX notably reversed the ketamine-induced changes in the levels of Nestin and β-tubulin III. In addition, a pretreatment with 10 μg/kg DEX before ketamine anesthesia prevented apoptosis in the SVZ induced by neonatal ketamine exposure. Conclusions: Based on our findings, DEX may exert neuroprotective effects on the proliferation and differentiation of NSCs in the SVZ of neonatal rats in a repeated ketamine anesthesia model.


2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Xiyao Pang ◽  
Yanqiu Wang ◽  
Jintao Wu ◽  
Zhou Zhou ◽  
Tao Xu ◽  
...  

Yunnan Baiyao is a traditional Chinese herbal remedy that has long been used for its characteristics of wound healing, bone regeneration, and anti-inflammation. However, the effects of Yunnan Baiyao on the odonto/osteogenic differentiation of stem cells from apical papilla (SCAPs) and the potential mechanisms remain unclear. The aim of this study was to investigate the odonto/osteogenic differentiation effects of Yunnan Baiyao on SCAPs and the underlying mechanisms involved. SCAPs were isolated and cocultured with Yunnan Baiyao conditioned media. The proliferation ability was determined by cell counting kit 8 and flow cytometry. The differentiation capacity and the involvement of NF-κB pathway were investigated by alkaline phosphatase assay, alizarin red staining, immunofluorescence assay, real-time RT-PCR, and western blot analyses. Yunnan Baiyao conditioned medium at the concentration of 50 μg/mL upregulated alkaline phosphatase activity, induced more mineralized nodules, and increased the expression of odonto/osteogenic genes/proteins (e.g., OCN/OCN, OPN/OPN, OSX/OSX, RUNX2/RUNX2, ALP/ALP, COL-I/COL-I, DMP1, DSP/DSPP) of SCAPs. In addition, the expression of cytoplasmic phos-IκBα, phos-P65, and nuclear P65 was significantly increased in Yunnan Baiyao conditioned medium treated SCAPs in a time-dependent manner. Conversely, the differentiation of Yunnan Baiyao conditioned medium treated SCAPs was obviously inhibited when these stem cells were cocultured with the specific NF-κB inhibitor BMS345541. Yunnan Baiyao can promote the odonto/osteogenic differentiation of SCAPs via the NF-κB signaling pathway.


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