scholarly journals Neuroserpin Protects Rat Neurons and Microglia-Mediated Inflammatory Response Against Oxygen-Glucose Deprivation- and Reoxygenation Treatments in an In Vitro Study

2016 ◽  
Vol 38 (4) ◽  
pp. 1472-1482 ◽  
Author(s):  
Xuelian Yang ◽  
Tetsuya Asakawa ◽  
Sha Han ◽  
Ling Liu ◽  
Wei Li ◽  
...  

Background/Aims: Neuroserpin (NSP) is known for its neuroprotective role in cerebral ischemic animal models and patients. Our laboratory conducted a series of investigations on the neuroprotection of NSP in different cells in the brain. In the present study, we further observe the effects of NSP on neurons and microglia-mediated inflammatory response following oxygen-glucose deprivation (OGD), and explore possible mechanisms related to neuroprotection of OGD in the central nervous system (CNS). Methods: Neurons and microglia from neonatal rats were treated with OGD followed by reoxygenation (OGD/R). To confirm the effects of NSP, the neuronal survival, neuronal apoptosis, and lactate dehydrogenase (LDH) release were measured in cultured neurons. Furthermore, the levels of IL-1β and nitric oxide (NO) release were also detected in cultured microglia. The possible mechanisms for the neuroprotective effect of NSP were explored using Western blot analysis. Results: NSP administration can reverse abnormal variations in neurons and microglia-mediated inflammatory response induced by OGD/R processes. The neuronal survival rate, neuronal apoptosis rate, and LDH release were significantly improved by NSP administration in neurons. Simultaneously, the release of IL-1β and NO were significantly reduced by NSP in microglia. Western blot showed that the expression of ERK, P38, and JNK was upregulated in microglia by the OGD/R treatment, and these effects were significantly inhibited by NSP. Conclusion: These data verified the neuroprotective effects of NSP on neurons and microglia-mediated inflammatory response. Inhibition of the mitogen-activated protein kinase (MAPK) signaling pathways might play a potential role in NSP neuroprotection on microglia-mediated inflammatory response, which needs further verification.

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 49 (5) ◽  
pp. 56-62
Author(s):  
Hongtao Chen ◽  
Li Zhang

Background and objective: Osteoarthritis is the most common chronic osteoarthrosis disease. There are complex factors that lead to osteoarthritis. Therefore, it is essential to investigate the molecular mechanism of osteoarthritis, especially the mechanism of articular cartilage degeneration. In this study, the mechanism of FPR1 (formyl peptide receptor 1) in LPS (lipopolysaccharide) induced chondrogenic cell ATDC5 was investigated.Materials and methods: We employed real-time quantitative polymerase chain reaction (RT-qPCR) and western blot assay to analyze the expression level of FPR1 in ATDC5 cell linesinduced by LPS at 0, 2.5, 5, and 10 μg/mL concentrations. Then we constructed the FPR1 knockdown plasmid to transfect the LPS-ATDC5. MTT assay was used to test cell viability in control, LPS, LPS+shNC and LPS+shFPR1 groups. ELISA and RT-qPCR assay were employed to examine the TNF-α (tumor necrosis factor-α)、IL-6 and IL-1β expression level. Flow cytometry and western blot assay were employed to analyze the apoptosis of LPS-ATDC5. Finally, we utilized the western blot assay to text related protein expression level of MAPK (mitogen-activated protein kinase) signaling pathway.Results: In this study, we found the expression level of FPR1 was increased in LPS-ATDC5, downregulation of FPR1 improves the survival rate and alleviates inflammatory response of LPS-ATDC5. Meanwhile, downregulation of FPR1 alleviates apoptosis of LPS-ATDC5. Finally, downregulation of FPR1 inhibits the MAPK signal pathway.Conclusion: Present study revealed that FPR1 was highly expressed in LPS-induced chondrocytes ATDC5, and the downregulation of FPR1 abated the inflammatory response and apoptosis of LPS-ATDC5 cells by regulating the MAPK signaling pathway.


2021 ◽  
Vol 18 ◽  
Author(s):  
Li-yun Kong ◽  
Yan Li ◽  
Ding-yu Rao ◽  
Bing Wu ◽  
Cheng-peng Sang ◽  
...  

Background: Previous studies have reported that mesenchymal stem cell (MSC)-derived exosomes can protect rat primary brain microvascular endothelial cells (BMECs) against oxygen–glucose deprivation and reoxygenation (OGD/R)-induced injury. Objective: To identify the key factors mediating the protective effects of MSC-derived exosomes. Methods: Rat primary BMECs were either pretreated or not pretreated with MSC-derived exosomes before exposure to OGD/R. Naïve cells were used as a control. After performing small RNA deep sequencing, quantitative reverse transcription polymerase chain reaction was performed to validate microRNA (miRNA) expression. The effects of rno-miR-666-3p on cell viability, apoptosis, and inflammation in OGD/R-exposed cells were assessed by performing the Cell Counting Kit 8 assay, flow cytometry, and enzyme-linked immunosorbent assay, respectively. Moreover, the role of rno-miR-666-3p in regulating gene expression in OGD/R-exposed cells was studied using mRNA deep sequencing. Lastly, to evaluate whether mitogen-activated protein kinase 1 (MAPK1) was the target of rno-miR-666-3p, western blotting and the dual-luciferase assay were performed. Results: MSC-derived exosomes altered the miRNA expression patterns in OGD/R-exposed BMECs. In particular, the expression levels of rno-miR-666-3p, rno-miR-92a-2-5p, and rno-miR-219a-2-3p decreased in OGD/R-exposed cells compared with those in the control; however, MSC-derived exosomes restored the expression levels of these miRNAs under OGD/R conditions. rno-miR-666-3p overexpression enhanced cell viability and alleviated the apoptosis of OGD/R-exposed cells. Moreover, rno-miR-666-3p suppressed OGD/R-induced inflammation. mRNA deep sequencing revealed that rno-miR-666-3p is closely associated with the MAPK signaling pathway. Western blotting and the dual-luciferase assay confirmed that MAPK1 is the target of rno-miR-666-3p. Conclusion: MSC-derived exosomes restore rno-miR-666-3p expression in OGD/R-exposed BMECs. Moreover, this specific miRNA exerts protective effects against OGD/R by suppressing the MAPK signaling pathway.


2021 ◽  
pp. 096032712198941
Author(s):  
H Ding ◽  
Z Wang ◽  
W Song

Objective: C1q/TNF-related protein 3 (CTRP3), a member of CTRP family, has been found to have neuroprotective effect. In the current study, we investigated the protective role of CTRP3 in hippocampal neurons exposed to oxygen-glucose deprivation/reperfusion (OGD/R). Materials and methods: The mRNA and protein levels of CTRP3 in OGD/R-stimulated hippocampal neurons were measured using qRT-PCR and western blot analysis, respectively. CCK-8 assay was performed to assess cell viability. ROS production was measured using the fluorescence probe 2′,7′-dichlorofluorescein diacetate (H2DCFDA). The activities of SOD and GPx were determined using ELISA. Cell apoptosis was assessed. Luciferase reporter assay was carried out to assess the activation of ARE). The levels of p-AMPK and Nrf2 were measured using western blot. Results: Our results showed that the expression of CTRP3 was significantly downregulated in hippocampal neuronal cells exposed to OGD/R. Overexpression of CTRP3 improved cell viability of OGD/R-induced hippocampal neurons. In addition, overexpression of CTRP3 attenuated the OGD/R-caused oxidative stress with decreased ROS production and increased activities of SOD and GPx. Moreover, CTRP3 caused a significant increase in bcl-2 expression and decreases in bax expression and caspase-3 activity. Furthermore, CTRP3 overexpression significantly upregulated the levels of p-AMPK and Nrf2, as well induced the activation of ARE in OGD-R-induced hippocampal neurons. CTRP3 upregulated the mRNA expression levels of HO-1, NQO-1 and GPx-3. Additionally, treatment with the inhibitor of AMPK partially reversed the neuroprotective effect of CTRP3 in OGD/R-exposed neurons. Conclusion: CTRP3 exerted protective effect on OGD/R-induced cerebral injury, which was regulated by AMPK/Nrf2/ARE pathway.


2020 ◽  
pp. 1-11
Author(s):  
Song Yi ◽  
Chuqin Zhang ◽  
Na Li ◽  
Yajing Fu ◽  
Hongkun Li ◽  
...  

<b><i>Objective:</i></b> Recent reports have corroborated that micro­RNAs (miRs) are related to the pathological changes of cerebral ischemia-reperfusion (CIR) induced injury. This work aimed to unearth the role and potential mechanism of miR-325-3p in regulating neuronal survival in CIR injury. <b><i>Methods:</i></b> To conduct this investigation, we established an in vitro model of CIR injury by subjecting neurons to oxygen-glucose deprivation and reoxygenation (OGD/R). Gain and loss of function of miR-325-3p and receptor-interacting serine-threonine kinase 3 (RIP3) in neurons were performed to observe its effect on cell apoptosis and the release of lactate dehydrogenase. The levels of miR-325-3p and RIP3 in neurons were detected by qRT-PCR. Western blot was employed to inspect the levels of caspase3, Bax, and Bcl-2, as well as p38 and JNK phosphorylation. The relationship between miR-325-3p and RIP3 was detected by TargetScan and validated by dual-luciferase reporter assay. <b><i>Results:</i></b> Firstly, miR-325-3p expression was obviously downregulated while RIP3 expression was upregulated in neurons following OGD/R treatment. Overexpressed miR-325-3p or downexpressed RIP3 ameliorated OGD/R-induced neuronal injury. Besides, RIP3 was a direct target mRNA of miR-325-3p. Additionally, Western blot revealed the mitogen-activated protein kinase (MAPK) pathway was involved in the regulation of miR-325-3p on OGD/R-induced neuronal injury. Furthermore, miR-325-3p was verified to hinder OGD/R-induced neuronal injury through downregulating RIP3. <b><i>Conclusion:</i></b> This study demonstrated that miR-325-3p targets RIP3 to inactivate the MAPK pathway, thereby protecting neurons against OGD/R-induced injury.


2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Zhenzhen Hu ◽  
Ya Yuan ◽  
Xiuli Zhang ◽  
Yifeng Lu ◽  
Na Dong ◽  
...  

Background. Mesenchymal stem cell-derived exosomes (MSC-exos) have been recognized as a promising therapeutic strategy for neonatal hypoxic-ischemic brain damage (HIBD). Recently, microglial pyroptosis was shown to play a vital role in the progression of neonatal HIBD. However, whether MSC-exos improve HIBD by regulating microglial pyroptosis remains unknown. Methods. Exosomes were isolated from human umbilical cord mesenchymal stem cells (huMSCs) and identified by transmission electron microscopy (TEM), western blot, and nanoparticle tracking analysis (NTA). BV-2 cells were subjected to oxygen-glucose deprivation/reoxygenation (OGD/R) to induce microglial ischemia/reperfusion (I/R) in vitro. CCK-8, ELISA, western blot, and Hoechst 33342/PI double staining were performed to detect the pyroptosis of BV-2 cells. Conditioned medium (CM) from BV-2 cells exposed to different treatments was used to investigate its effect on neuronal injury. Moreover, 3-methyladenine (3-MA) and mitochondrial division inhibitor-1 (mdi-1) were used to verify the involvement of mitophagy in the protection of MSC-exos against OGD/R-induced pyroptosis in BV-2 cells. Finally, FOXO3a siRNA was used to investigate the involvement of FOXO3a in MSC-exo-induced mitophagy and pyroptosis inhibition. Results. Exosomes from huMSCs were successfully extracted. In OGD/R-exposed BV-2 cells, MSC-exos increased cell viability and decreased the expression of NLRP3, cleaved caspase-1, and GSDMD-N as well as the release of IL-1β and IL-18. Compared with CM from OGD/R-exposed BV-2 cells treated with PBS, CM from OGD/R-exposed BV-2 cells treated with MSC-exos significantly increased the viability of SH-SY5Y cells and decreased LDH release. MSC-exos also increased the expression of TOM20 and COX IV in OGD/R-exposed BV-2 cells. Additionally, 3-MA and mdi-1 attenuated the inhibition of pyroptosis with MSC-exo treatment. Furthermore, FOXO3a siRNA partially abolished the neuroprotective effect of MSC-exos and attenuated mitophagy and pyroptosis inhibition induced by MSC-exo treatment. Conclusions. Our findings demonstrated that MSC-exos increased FOXO3a expression to enhance mitophagy, therefore protecting microglia from I/R-induced pyroptosis and alleviating subsequent neuronal injury.


2008 ◽  
Vol 28 (7) ◽  
pp. 1307-1319 ◽  
Author(s):  
Sherri L Christian ◽  
Austin P Ross ◽  
Huiwen W Zhao ◽  
Heidi J Kristenson ◽  
Xinhua Zhan ◽  
...  

Oxygen—glucose deprivation (OGD) initiates a cascade of intracellular responses that culminates in cell death in sensitive species. Neurons from Arctic ground squirrels (AGS), a hibernating species, tolerate OGD in vitro and global ischemia in vivo independent of temperature or torpor. Regulation of energy stores and activation of mitogen-activated protein kinase (MAPK) signaling pathways can regulate neuronal survival. We used acute hippocampal slices to investigate the role of ATP stores and extracellular signal-regulated kinase (ERK)1/2 and Jun NH2-terminal kinase (JNK) MAPKs in promoting survival. Acute hippocampal slices from AGS tolerated 30 mins of OGD and showed a small but significant increase in cell death with 2 h OGD at 37 C. This tolerance is independent of hibernation state or season. Neurons from AGS survive OGD despite rapid ATP depletion by 3 mins in interbout euthermic AGS and 10 mins in hibernating AGS. Oxygen—glucose deprivation does not induce JNK activation in AGS and baseline ERK1/2 and JNK activation is maintained even after drastic depletion of ATP. Surprisingly, inhibition of ERK1/2 or JNK during OGD had no effect on survival, whereas inhibition of JNK increased cell death during normoxia. Thus, protective mechanisms promoting tolerance to OGD by AGS are downstream from ATP loss and are independent of hibernation state or season.


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.


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