Abstract TP266: Phenothiazines Enhance Mild Hypothermia-induced Neuroprotection via PI3K/Akt Regulation in Experimental Ischemia/Reperfusion Injury

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Hong An ◽  
Joshua Wright ◽  
Yunxia Duan ◽  
Di Wu ◽  
Xunming Ji ◽  
...  

Introduction: Hypothermia is an effective neuroprotectant against stroke, but its application is limited by delayed onset, prolonged duration, and significant complications. Mild hypothermia is more clinically practical but offers weaker neuroprotection. This study investigated whether the neuroprotective effects of mild hypothermia can be enhanced by phenothiazine neuroleptics (chlorpromazine and promethazine), which were reported to have depressive or hibernation-like roles on the CNS. We also worked to elucidate the role of the PI3K/Akt signaling pathway in this protective mechanism. Methods: A total of 131 adult male Sprague-Dawley rats were randomly divided into 6 groups: sham, stroke without treatment (2-hour right middle cerebral artery occlusion), and 4 treatment groups with 1) mild hypothermia (anal temperature 33-35 0 C), 2) phenothiazines (1mg/kg chlorpromazine & 1mg/kg promethazine, anal temperature 37.8-38.3 0 C), 3) combination of mild hypothermia and phenothiazines, and 4) both therapies with the addition of a p-Akt antagonist (LY294002 was injected into the lateral ventricle 30 minutes before ischemia). Infarct volume, neurological deficit, and apoptotic cell death were determined 24h post reperfusion. Expression of p-Akt, cleaved Caspase-3, pro-apoptotic (AIF & Bax) and anti-apoptotic proteins (Bcl-2 & Bcl-xL) was assessed by Western blot at 6h and 24h after reperfusion. Results: The combination of hypothermia and phenothiazines decreased (P<0.01) infarct volume and neurological deficit. This change was associated with a reduction (P<0.01) of apoptotic cell death. Each treatment alone did not induce significant neuroprotection. The combination therapy, but not each alone, promoted (P<0.01) the expression of p-Akt, accompanied with increased expression of anti-apoptotic proteins and decreased expression of pro-apoptotic proteins. The neuroprotective effects were blocked by p-Akt inhibition. Conclusion: Mild hypothermia-induced neuroprotection was enhanced by phenothiazines in an experimental ischemia/reperfusion injury model. This study supports the involvement of the PI3K/Akt signaling pathway. This novel therapeutic strategy could be developed as an effective treatment for acute ischemic stroke.

Author(s):  
Xueying Tong ◽  
Jiajuan Chen ◽  
Wei Liu ◽  
Hui Liang ◽  
Hezhong Zhu

AbstractCardiovascular diseases rank the top cause of morbidity and mortality worldwide and are usually associated with blood reperfusion after myocardial ischemia/reperfusion injury (MIRI), which often causes severe pathological damages and cardiomyocyte apoptosis. LSINCT5 expression in the plasma of MI patients (n = 53), healthy controls (n = 42) and hypoxia-reoxygenation (HR)-treated cardiomyocyte AC16 cells was examined using qRT-PCR. The effects of LSINCT5 on cell viability and apoptosis were detected by MTT and flow cytometry, respectively. The expression of apoptosis-related proteins Bcl2, Bax and caspase 3 were tested by Western blot. The interaction between LSINCT5 and miR-222 was predicted by bioinformatic analysis. Moreover, changes in viability and apoptosis of AC16 cells co-transfected with siLSINCT5 and miR-222 inhibitor after HR treatment were examined. At last, the expression of proteins in PI3K/AKT pathway, namely PTEN, PI3K and AKT, was examined to analyze the possible pathway participating in LSINCT5-mediated MI/RI. Our study showed that LSINCT5 expression was upregulated in the plasma of MI patients and HR-treated AC16 cells. LSINCT5 overexpression significantly decreased cell viability and apoptosis. Luciferase reporter gene assay and RNA pulldown assay showed that LSINCT5 was a molecular sponge of miR-222. MiR-222 silencing in AC16 cells simulated the phenotypes of MIRI patients and HR-treated cells, indicating that LSINCT5 functions via miR-222 to regulate proliferation and apoptosis of HR-treated AC16 cells. We also showed that proteins of PI3K/AKT signaling pathway were affected in HR-treated AC16 cells, and LSINTC5 knockdown rescued these effects. LncRNA LSINCT5 was upregulated during MI pathogenesis, and LSINCT5 regulated MIRI possibly via a potential LSINCT5/miR-222 axis and PI3K/AKT signaling pathway. Our findings may provide novel evidence for MIRI prevention.


2021 ◽  
Vol 12 (1) ◽  
pp. 210-217
Author(s):  
Yibiao Wang ◽  
Min Xu

Abstract Background This study aimed to explore the role of miR-380-5p in cerebral ischemia/reperfusion (CIR) injury-induced neuronal cell death and the potential signaling pathway involved. Methodology Human neuroblastoma cell line SH-SY5Y cells were used in this study. Oxygen and glucose deprivation/reperfusion (OGD/R) model was used to mimic ischemia/reperfusion injury. CCK-8 assay and flow cytometry were used to examine cell survival. Quantitative real time PCR (RT-qPCR) assay and Western blotting were used to measure the change of RNA and protein expression, respectively. TargetScan and Luciferase assay was used to confirm the target of miR-380-5p. Malondialdehyde (MDA) superoxide dismutase (SOD) and glutathione peroxidase (GSHPx) were measured using commercial kits. Results miR-380-5p was downregulated in SH-SY5Y cells after OGD/R. Cell viability was increased by miR-380-5p, while cell apoptosis was reduced by miR-380-5p mimics. MDA was reduced by miR-380-5p mimics, while SOD and GSHPx were increased by miR-380-5p. Results of TargetScan and luciferase assay have showed that BACH1 is the direct target of miR-380-5p. Expression of NRF2 was upregulated after OGD/R, but was not affected by miR-380-5p. mRNA expression of HO-1 and NQO1 and ARE activity were increased by miR-380-5p. Overexpression of BACH1 reversed the antioxidant and neuroprotective effects of miR-380-5p. Conclusion miR-380-5p inhibited cell death induced by CIR injury through target BACH1 which also facilitated the activation of NRF2, indicating the antioxidant and neuroprotective effects of miR-380-5p.


Stroke ◽  
2016 ◽  
Vol 47 (suppl_1) ◽  
Author(s):  
Kaiyin Liu ◽  
Lipeng Cai ◽  
Changya Peng ◽  
Xiaokun Geng ◽  
Xunming Ji ◽  
...  

Introduction: Neuroprotective effects of normobaric oxygen (NBO) and ethanol (EtOH) has been shown. In a clinically relevant autologous embolus rat stroke model in which reperfusion was established by tissue-type plasminogen activator (rt-PA), the present study further evaluated whether low concentration NBO enhanced therapeutic effect of mild hypothermia (Hypo) or EtOH through a reduction in apoptosis and whether EtOH can substitute for hypothermia. Hypothesis: Hypo and EtOH has been shown to have neuroprotective effects through similar mechanisms. We assessed the hypothesis that low concentration NBO, whose neuroprotective effects are currently debated, has benefit in our stroke models, and we further assessed the hypothesis that EtOH can substitute for Hypo in the presence of tPA and NBO. Methods: At 1 hour of middle cerebral artery occlusion (MCAO) by an autologous embolus, rats (96 total, 12 in each treatment group) received rt-PA and other treatments of either EtOH (1.0 g/kg) or Hypo (33 °C for 3 hours) in combination with NBO (60% for 3 hours). Apoptotic cell death was measured by ELISA. Western immunoblotting was performed for pro- (AIF, Caspase-3, Bax) and anti-apoptotic (Bcl-2) protein expression at 3 and 24 hours of reperfusion. Results: Compared to ischemic rats treated only with rt-PA, animals with NBO, hypothermia or EtOH had significantly reduced apoptotic cell death by 32.5%, 43.1% and 36.0% respectively. However, combination therapy that included NBO+EtOH or NBO+Hypo with rt-PA exhibited a much larger decline (p<0.01) in the cell death by 71.1% and 73.6%, respectively. Similarly, NBO+EtOH or NBO+Hypo treatment in addition to rt-PA enhanced beneficial effects on both pro- and anti-apoptotic protein expressions as compared to other options. Conclusions: Neuroprotection after reperfusion with rt-PA in ischemic stroke induced by thromboembolism are enhanced by combination treatment with either EtOH or Hypo in the presence of 60% NBO through reduced apoptosis. Since the effects produced by EtOH and Hypo are comparable, their mechanism of action may not only be similar but also could be interchangeable. Since EtOH administration does not lead to temperature decrease, EtOH may a better alternative than Hypo.


Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2884 ◽  
Author(s):  
Eun-Jung In ◽  
Yuno Lee ◽  
Sushruta Koppula ◽  
Tae-Yeon Kim ◽  
Jun-Hyuk Han ◽  
...  

Necroptosis, or caspase-independent programmed cell death, is known to be involved in various pathological conditions, such as ischemia/reperfusion injury, myocardial infarction, atherosclerosis, and inflammatory bowel diseases. Although several inhibitors of necroptosis have been identified, none of them are currently in clinical use. In the present study, we identified a new compound, 4-({[5-(4-aminophenyl)-4-ethyl-4H-1,2,4-triazol-3-yl]sulfanyl}methyl)-N-(1,3-thiazol-2-yl) benzamide (NTB451), with significant inhibitory activity on the necroptosis induced by various triggers, such as tumor necrosis factor-α (TNF-α) and toll-like receptor (TLR) agonists. Mechanistic studies revealed that NTB451 inhibited phosphorylation and oligomerization of mixed lineage kinase domain like (MLKL), and this activity was linked to its inhibitory effect on the formation of the receptor interacting serine/threonine-protein kinase 1 (RIPK1)-RIPK3 complex. Small interfering RNA (siRNA)-mediated RIPK1 knockdown, drug affinity responsive target stability assay, and molecular dynamics (MD) simulation study illustrated that RIPK1 is a specific target of NTB451. Moreover, MD simulation showed a direct interaction of NTB451 and RIPK1. Further experiments to ensure that the inhibitory effect of NTB451 was restricted to necroptosis and NTB451 had no effect on nuclear factor-κB (NF-κB) activation or apoptotic cell death upon triggering with TNF-α were also performed. Considering the data obtained, our study confirmed the potential of NTB451 as a new necroptosis inhibitor, suggesting its therapeutic implications for pathological conditions induced by necroptotic cell death.


2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Shuai Yang ◽  
Bin Hu ◽  
Zongming Wang ◽  
Changming Zhang ◽  
Haosen Jiao ◽  
...  

Abstract Activation of the cannabinoid CB1 receptor induces neuroprotection against brain ischemia/reperfusion injury (IRI); however, the mechanism is still unknown. In this study, we used oxygen-glucose deprivation/reoxygenation (OGD/R)-induced injury in neuronal cells and middle cerebral artery occlusion (MCAO)-induced brain IRI in rats to mimic ischemic brain injury, and hypothesized that the CB1 receptor agonist arachidonyl-2-chloroethylamide (ACEA) would protect ischemic neurons by inhibiting mitochondrial fission via dynamin-related protein 1 (Drp1). We found that OGD/R injury reduced cell viability and mitochondrial function, increased lactate dehydrogenase (LDH) release, and increased cell apoptosis, and mitochondrial fission. Notably, ACEA significantly abolished the OGD/R-induced neuronal injuries described above. Similarly, ACEA significantly reversed MCAO-induced increases in brain infarct volume, neuronal apoptosis and mitochondrial fission, leading to the recovery of neurological functions. The neuroprotective effects of ACEA were obviously blocked by coadministration of the CB1 receptor antagonist AM251 or by the upregulation of Drp1 expression, indicating that ACEA alleviates brain IRI via the CB1–Drp1 pathway. Our findings suggest that the CB1 receptor links aberrant mitochondrial fission to brain IRI, providing a new therapeutic target for brain IRI treatment.


2020 ◽  
Vol 20 (5) ◽  
pp. 396-406 ◽  
Author(s):  
Liangtong Li ◽  
Xiangzi Li ◽  
Zhe Zhang ◽  
Li Liu ◽  
Tongtong Liu ◽  
...  

Background: The effects of hydrogen-rich water on PI3K/AKT-mediated apoptosis were studied in rats subjected to myocardial ischemia-reperfusion injury (MIRI). Methdos: Sixty rats were divided randomly into a hydrogen-rich water group and a control group. The hearts were removed and fixed in a Langendorff device. Hearts from the control group were perfused with K-R solution, and hearts from the hydrogen-rich water group was perfused with K-R solution + hydrogen-rich water. The two treatment groups were then divided randomly into pre-ischemic period, ischemic period and reperfusion period groups(10 rats per group), which were subjected to reverse perfusion for 10 min, normal treatment for 20 min, and reperfusion for 20 min, respectively. The mRNA and protein expression levels of PI3K, AKT, p-AKT, FoxO1, Bim and Caspase-3 in each group were detected by RT-qPCR, immunohistochemistry (IHC) and Western blotting. Caspase-3 activity was detected by spectrophotometry. Results: Among the hydrogen-rich water group, the PI3K/AKT signaling pathway was significantly activated, and FoxO1, Bim, and Caspase-3 mRNA and protein levels were significantly decreased in ischemia-reperfusion subgroup compared with the preischemic and ischemic subgroups. In the ischemia-reperfusion hydrogen-rich water group, PI3K, AKT and p-AKT mRNA and protein expression levels were increased while the FoxO1, Bim and Caspase-3 expression levels were significantly decreased compared with those in the corresponding control group (p<0.05). Conclusion: Hydrogen-rich water can activate the PI3K/AKT signaling pathway, alleviate ischemia-reperfusion injury in isolated rat hearts, and inhibit cardiomyocyte apoptosis.


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