scholarly journals ADAM8 Activates NLRP3 Inflammasome to Promote Cerebral Ischemia-Reperfusion Injury

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Hongwei Lu ◽  
Yaqin Meng ◽  
Xinrui Han ◽  
Wei Zhang
Keyword(s):  
Cerebral Ischemia ◽  
Inflammatory Response ◽  
Nlrp3 Inflammasome ◽  
Transmembrane Protein ◽  
Ischemia Reperfusion ◽  
Cortical Cell ◽  
Ischemic Injury ◽  
Neurological Deficits ◽  
Cerebral Ischemic Injury ◽  
Cerebral Ischemic

Stroke is the leading cause of death and disability in humans. Strokes are classified as either ischemic or hemorrhagic. Ischemic stroke accounts for 70–80% of the cases. Inflammation is a key factor in ischemic brain injury. Studies have shown that inflammatory response induced by NLRP3 inflammasome is one of the root causes of brain damage in mice with cerebral ischemia. However, its specific mechanism in cerebral ischemia is still unclear. ADAM8 (a disintegrin and metalloproteases 8) is a transmembrane protein with different functions. It plays an important role in tumors and neuroinflammation-related diseases. However, the role and molecular mechanism of ADAM8 in cerebral ischemia injury are still unclear. This study aims to evaluate the role of ADAM8 in cerebral ischemic injury and explore its signal transduction mechanism. This experiment shows that ADAM8 can significantly cause neurological deficits in MCAO mice and can substantially cause ipsilateral cerebral edema and cerebral infarction in MCAO mice. In addition, ADAM8 can significantly induce cortical cell apoptosis in MCAO mice, leading to the loss of neurons and the expression of proinflammatory factors COX2, iNOS, TNFα, and IL-6. Importantly, we confirmed that ADAM8 mediates the inflammatory response by promoting the activation of NLRP3 inflammasome, microglia, and astrocytes. These results indicate that ADAM8 may be a candidate drug target for the prevention and treatment of the cerebral ischemic injury.

scholarly journals Curcumin Protects Neuron against Cerebral Ischemia-Induced Inflammation through Improving PPAR-Gamma Function

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Zun-Jing Liu ◽  
Wei Liu ◽  
Lei Liu ◽  
Cheng Xiao ◽  
Yu Wang ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Neuronal Damage ◽  
Infarct Volume ◽  
Critical Role ◽  
Ischemic Injury ◽  
Ppar Gamma ◽  
Neurological Deficits ◽  
Protective Effects ◽  
Cerebral Ischemic Injury ◽  
Cerebral Ischemic

Cerebral ischemia is the most common cerebrovascular disease worldwide. Recent studies have demonstrated that curcumin had beneficial effect to attenuate cerebral ischemic injury. However, it is unclear how curcumin protects against cerebral ischemic injury. In the present study, using rat middle cerebral artery occlusion model, we found that curcumin was a potent PPARγagonist in that it upregulated PPARγexpression and PPARγ-PPRE binding activity. Administration of curcumin markedly decreased the infarct volume, improved neurological deficits, and reduced neuronal damage of rats. In addition, curcumin suppressed neuroinflammatory response by decreasing inflammatory mediators, such as IL-1β, TNF-α, PGE2, NO, COX-2, and iNOS induced by cerebral ischemia of rats. Furthermore, curcumin suppressed IκB degradation that was caused by cerebral ischemia. The present data also showed that PPARγinteracted with NF-κB-p65 and thus inhibited NF-κB activation. All the above protective effects of curcumin on cerebral ischemic injury were markedly attenuated by GW9662, an inhibitor of PPARγ. Our results as described above suggested that PPARγinduced by curcumin may play a critical role in protecting against brain injury through suppression of inflammatory response. It also highlights the potential of curcumin as a therapeutic agent against cerebral ischemia.

N-Myc Downstream-Regulated Gene 2 (Ndrg2): A Critical Mediator of Estrogen-Induced Neuroprotection Against Cerebral Ischemic Injury

2021 ◽  
Author(s):  
Lixia Zhang ◽  
Yulong Ma ◽  
Min Liu ◽  
Miao Sun ◽  
Jin Wang ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Neuroprotective Effect ◽  
Ischemic Injury ◽  
Artery Occlusion ◽  
Male Mice ◽  
Neuroprotective Effects ◽  
Female Mice ◽  
Ndrg2 Expression ◽  
Cerebral Ischemic Injury ◽  
Cerebral Ischemic

Abstract Growing evidence indicates that estrogen plays a pivotal role in neuroprotection against cerebral ischemia, but the molecular mechanism of this protection is still elusive. N-myc downstream‐regulated gene 2 (Ndrg2), an estrogen-targeted gene, has been shown to exert neuroprotective effects against cerebral ischemia in male mice. However, the role of Ndrg2 in the neuroprotective effect of estrogen remains unknown. In this study, we first detected NDRG2 expression levels in the cortex and striatum in both female and male mice with western blot analyses. We then detected cerebral ischemic injury by constructing middle cerebral artery occlusion and reperfusion (MCAO-R) models in Ndrg2 knockout or conditional knockdown female mice. We further implemented estrogen, ERα or ERβ agonist replacement in the ovariectomized (OVX) Ndrg2 knockouts or conditional knockdowns female mice, then tested for NDRG2 expression, glial fibrillary acidic protein (GFAP) expression, and extent of cerebral ischemic injury. We found that NDRG2 expression was significantly higher in female than in male mice in both the cortex and striatum. Ndrg2 knockouts and conditional knockdowns showed significantly aggravated cerebral ischemic injury in female mice. Estrogen and ERβ replacement treatment (DPN) led to NDRG2 upregulation in both the cortex and striatum of OVX mice. Estrogen and DPN also led to GFAP upregulation in OVX mice. However, the effect of estrogen and DPN in activating astrocytes was lost in Ndrg2 knockouts OVX mice and primary cultured astrocytes, but partially retained in conditional knockdowns OVX mice. Most importantly, we found that the neuroprotective effects of E2 and DPN against cerebral ischemic injury were lost in Ndrg2 knockouts OVX mice but partially retained in conditional knockdowns OVX mice. These findings demonstrate that estrogen alleviated cerebral ischemic injury via ERβ upregulation of Ndrg2, which could activate astrocytes, indicating that Ndrg2 is a critical mediator of E2-induced neuroprotection against cerebral ischemic injury.

scholarly journals Deletion of Aldose Reductase Leads to Protection against Cerebral Ischemic Injury

2007 ◽  
Vol 27 (8) ◽  
pp. 1496-1509 ◽  
Author(s):  
Amy CY Lo ◽  
Alvin KH Cheung ◽  
Victor KL Hung ◽  
Chung-Man Yeung ◽  
Qing-Yu He ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Aldose Reductase ◽  
Therapeutic Potential ◽  
Ischemic Injury ◽  
Adenosine Diphosphate ◽  
Polyol Pathway ◽  
Neurological Deficits ◽  
Cerebral Ischemic Injury ◽  
Cerebral Ischemic ◽  
Transient Focal Ischemia

Previously, we reported that transgenic mice overexpressing endothelin-1 in astrocytes showed more severe neurological deficits and increased infarct after transient focal ischemia. In those studies, we also observed increased level of aldose reductase (AR), the first and rate-limiting enzyme of the polyol pathway, which has been implicated in osmotic and oxidative stress. To further understand the involvement of the polyol pathway, the mice with deletion of enzymes in the polyol pathway, AR, and sorbitol dehydrogenase (SD), which is the second enzyme in this pathway, were challenged with similar cerebral ischemic injury. Deletion of AR-protected animals from severe neurological deficits and large infarct, whereas similar protection was not observed in mice with SD deficiency. Most interestingly, AR−/− brains showed lowered expression of transferrin and transferrin receptor with less iron deposition and nitrotyrosine accumulation. The protection against oxidative stress in AR−/− brain was also associated with less poly(adenosine diphosphate-ribose) polymerase (PARP) and caspase-3 activation. Pharmacological inhibition of AR by Fidarestat also protected animals against cerebral ischemic injury. These findings are the first to show that AR contributes to iron- and transferrin-related oxidative stress associated with cerebral ischemic injury, suggesting that inhibition of AR but not SD may have therapeutic potential against cerebral ischemic injury.

scholarly journals Prolonged Fasting Improves Endothelial Progenitor Cell-Mediated Ischemic Angiogenesis in Mice

2016 ◽  
Vol 40 (3-4) ◽  
pp. 693-706 ◽  
Author(s):  
Bao Xin ◽  
Chun-Long Liu ◽  
Hong Yang ◽  
Cheng Peng ◽  
Xiao-Hui Dong ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Endothelial Progenitor Cell ◽  
Progenitor Cell ◽  
Ischemic Injury ◽  
Prolonged Fasting ◽  
Endothelial Progenitor ◽  
Ischemic Brain ◽  
Cerebral Ischemic Injury ◽  
Cerebral Ischemic

Background/Aims: Prolonged fasting (PF) was shown to be of great potency to promote optimal health and reduce the risk of many chronic diseases. This study sought to determine the effect of PF on the endothelial progenitor cell (EPC)-mediated angiogenesis in the ischemic brain and cerebral ischemic injury in mice. Methods: Mice were subjected to PF or periodic PF after cerebral ischemia, and histological analysis and behavioral tests were performed. Mouse EPCs were isolated and examined, and the effects of EPC transplantation on cerebral ischemic injury were investigated in mice. Results: It was found that PF significantly increased the EPC functions and angiogenesis in the ischemic brain, and attenuated the cerebral ischemic injury in mice that was previously subjected to cerebral ischemia. Periodic PF might reduce cortical atrophy and improve long-term neurobehavioral outcomes after cerebral ischemia in mice. The eNOS and MnSOD expression and intracellular NO level were increased, and TSP-2 expression and intracellular O2- level were reduced in EPCs from PF-treated mice compared to control. In addition, transplanted EPCs might home into ischemic brain, and the EPCs from PF-treated mice had a stronger ability to promote angiogenesis in ischemic brain and reduce cerebral ischemic injury compared to the EPCs from control mice. The EPC-conditioned media from PF-treated mice exerted a stronger effect on cerebral ischemic injury reduction compared to that from control mice. Conclusion: Prolonged fasting promoted EPC-mediated ischemic angiogenesis and improved long-term stroke outcomes in mice. It is implied that prolonged fasting might potentially be an option to treat ischemic vascular diseases.

scholarly journals Tetrandrine alleviates cerebral ischemia/reperfusion injury by suppressing NLRP3 inflammasome activation via Sirt-1

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9042
Author(s):  
Jun Wang ◽  
Ming Guo ◽  
Ruojia Ma ◽  
Maolin Wu ◽  
Yamei Zhang
Keyword(s):  
Cerebral Ischemia ◽  
Nlrp3 Inflammasome ◽  
Molecular Mechanisms ◽  
Infarct Volume ◽  
Ischemia Reperfusion ◽  
Sirtuin 1 ◽  
Neurological Deficits ◽  
Inflammasome Activation ◽  
Cerebral Ischemia Reperfusion ◽  
Nlrp3 Inflammasome Activation

Background & Aims Tetrandrine (Tet) has been reported to have anti-inflammatory effects and protect from the ischemic strokes. The NLRP3 inflammasome plays a key role in cerebral ischemia/reperfusion (I/R)-induced inflammatory lesions. However, the molecular mechanisms of Tet related to the progression of cerebral ischemia are still unclear. Therefore, the aim of this study was to investigate the possible effects of Tet on cerebral ischemia and the related mechanisms involved in NLRP3 inflammasome. Methods C57BL/6J mice used as a cerebral I/R injury model underwent middle cerebral artery occlusion (MCAO) for 2 h following reperfusion for 24 h. Tet (30 mg/kg/day, i.p.) was administered for seven days and 30 min before and after MCAO. Their brain tissues were evaluated for NLRP3 inflammasome and Sirtuin-1 (Sirt-1) expression. An intracerebroventricular injection of Sirt-1 siRNA was administered to assess the activation of the NLRP3 inflammasome. Results Tet significantly reduced the neurological deficits, infarction volume, and cerebral water content in MCAO mice. Moreover, it inhibited I/R-induced over expression of NLRP3, cleaved caspase-1, interleukin (IL)-1β, IL-18, and Sirt-1. Sirt-1 knockdown with siRNA greatly blocked the Tet-induced reduction of neurological severity score and infarct volume, and reversed the inhibition of NLRP3 inflammasome activation. Conclusion Our results demonstrate that Tet has benefits for cerebral I/R injury, which are partially related to the suppression of NLRP3 inflammasome activation via upregulating Sirt-1.

scholarly journals Low-density lipoprotein receptor (LDLR) regulates NLRP3-mediated neuronal pyroptosis following cerebral ischemia/reperfusion injury

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Rui Sun ◽  
Mengna Peng ◽  
Pengfei Xu ◽  
Feihong Huang ◽  
Yi Xie ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Cerebral Ischemia ◽  
Ischemia Reperfusion ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Neurological Deficits ◽  
Density Lipoprotein Receptor ◽  
Cerebral Ischemic

Abstract Background Inflammatory response has been recognized as a pivotal pathophysiological process during cerebral ischemic stroke. NLRP3 inflammasome, involved in the regulation of inflammatory cascade, can simultaneously lead to GSDMD-executed pyroptosis in cerebral ischemia. Low-density lipoprotein receptor (LDLR), responsible for cholesterol uptake, was noted to exert potential anti-inflammatory bioactivities. Nevertheless, the role of LDLR in neuroinflammation mobilized by cerebral ischemia/reperfusion (I/R) has not been investigated. Methods Ischemic stroke mice model was accomplished by middle cerebral artery occlusion. Oxygen-glucose deprivation was employed after primary cortical neuron was extracted and cultured. A pharmacological inhibitor of NLRP3 (CY-09) was administered to suppress NLPR3 activation. Histological and biochemical analysis were performed to assess the neuronal death both in vitro and in vivo. In addition, neurological deficits and behavioral deterioration were evaluated in mice. Results The expression of LDLR was downregulated following cerebral I/R injury. Genetic knockout of Ldlr enhanced caspase-1-dependent cleavage of GSDMD and resulted in severe neuronal pyroptosis. LDLR deficiency contributed to excessive NLRP3-mediated maturation and release of IL-1β and IL-18 under in vitro and in vivo ischemic conditions. These influences ultimately led to aggravated neurological deficits and long-term cognitive dysfunction. Blockade of NLRP3 substantially retarded neuronal pyroptosis in Ldlr−/− mice and cultured Ldlr−/− neuron after experimental stroke. Conclusions These results demonstrated that LDLR modulates NLRP3-mediated neuronal pyroptosis and neuroinflammation following ischemic stroke. Our findings characterize a novel role for LDLR as a potential therapeutic target in neuroinflammatory responses to acute cerebral ischemic injury.

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