scholarly journals Tongxinluo Exerts Inhibitory Effects on Pyroptosis and Amyloid-β Peptide Accumulation after Cerebral Ischemia/Reperfusion in Rats

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Bing Wang ◽  
Zhongkuan Lyu ◽  
Yuanjin Chan ◽  
Qiyue Li ◽  
Li Zhang ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Ischemia Reperfusion ◽  
Amyloid Β ◽  
Amyloid Β Peptide ◽  
Protective Effects ◽  
Glymphatic System ◽  
Pyrin Domain ◽  
Cerebral Ischemia Reperfusion ◽  
Potential Possibility ◽  
Important Pathway

Amyloid-β peptide (Aβ) accumulation is a detrimental factor in cerebral ischemia/reperfusion (I/R) injuries accounting for dementia induced by ischemic stroke. In addition to blood brain barrier (BBB), the glymphatic system mediated by aquaporin-4 (AQP-4) on astrocytic endfeet functions as an important pathway for the clearance of Aβ in the brain. Cerebral I/R induced astrocytic pyroptosis potentially causes the AQP-4 polarization loss and dysfunctional BBB-glymphatic system exacerbating the accumulation of Aβ. Furthermore, Aβ toxicity has been identified as a trigger of pyroptosis and BBB damage, suggesting an amplified effect of Aβ accumulation after cerebral I/R. Therefore, based on our previous work, this study was designed to explore the intervention effects of Tongxinluo (TXL) on astrocytic pyroptosis and Aβ accumulation after cerebral I/R in rats. The results showed that TXL intervention obviously alleviated the degree of pyroptosis by downregulating expression levels of cleaved caspase-11/1, N-terminal gasdermin D, nucleotide-binding oligomerization domain-like receptors pyrin domain containing 3 (NLRP3), interleukin-6 (IL-6), and cleaved IL-1β and abated astrocytic pyroptosis after cerebral I/R. Moreover, TXL intervention facilitated to restore AQP-4 polarization and accordingly relieve Aβ accumulation around astrocytes in ischemic cortex and hippocampus as well as the formation of toxic Aβ (Aβ1–42 oligomer). Our study indicated that TXL intervention could exert protective effects on ischemic brain tissues against pyroptotic cell death, inhibit astrocytic pyroptosis, and reduce toxic Aβ accumulation around astrocytes in cerebral I/R injuries. Furthermore, our study provides biological evidence for the potential possibility of preventing and treating poststroke dementia with TXL in clinical practice.

Protective Effect of Astragaloside on Focal Cerebral Ischemia/Reperfusion Injury in Rats

2010 ◽  
Vol 38 (03) ◽  
pp. 517-527 ◽  
Author(s):  
Yan-Yan Yin ◽  
Wei-Ping Li ◽  
Hui-Ling Gong ◽  
Fen-Fang Zhu ◽  
Wei-Zu Li ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Cerebral Ischemia ◽  
Water Content ◽  
Neurological Deficit ◽  
Focal Cerebral Ischemia ◽  
Ischemia Reperfusion ◽  
Content Increase ◽  
Protective Effects ◽  
Neurological Deficit Score ◽  
Cerebral Ischemia Reperfusion

This study was to observe the neurological protective effects of astragalosides (AST) on focal cerebral ischemia-reperfusion (I/R) injury in rats and to explore its possible mechanism. Male SD rats received right middle cerebral artery occlusion for 120 min and AST (40 mg/kg) was orally administered. The rats were decapitated 1, 3, 7, and 14 days after reperfusion. The neurological deficit score, infarct volume and water content of brain were measured; the activity of superoxide dismutase (SOD), lactate dehydrogenase (LDH) and nitric oxide synthase (NOS), and the content of malondialdehyde (MDA), lactate (LD) and nitric oxide (NO) of brain tissue were detected too. The expression of inducible nitric synthase (iNOS), nerve growth factor (NGF) and tropomyosin receptor kinase A (TrkA) mRNA were measured by RT-PCR or real-time PCR. AST could significantly reduce the neurological deficit score; infract volume and water content, increase SOD and LDH activities, decrease NOS activity and MDA, LD and NO content. AST treatment could down-regulate expression of iNOS mRNA, while, NGF and TrkA mRNA were up-regulated. Our data suggest that AST have the protective effects on focal cerebral ischemia in rats at the different reperfusion time points, the mechanism may be related to the antioxidation, regulated the expressions of iNOS, NGF and TrkA mRNA.

scholarly journals Destructive Effects of Pyroptosis on Homeostasis of Neuron Survival Associated with the Dysfunctional BBB-Glymphatic System and Amyloid-Beta Accumulation after Cerebral Ischemia/Reperfusion in Rats

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Zhongkuan Lyu ◽  
Yuanjin Chan ◽  
Qiyue Li ◽  
Qiang Zhang ◽  
Kaili Liu ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Amyloid Beta ◽  
Neuronal Damage ◽  
Ischemia Reperfusion ◽  
Artery Occlusion ◽  
Neurological Deficits ◽  
Specific Marker ◽  
Nissl Staining ◽  
Glymphatic System ◽  
Cerebral Ischemia Reperfusion

Neuroinflammation-related amyloid-beta peptide (Aβ) accumulation after cerebral ischemia/reperfusion (I/R) accounts for cerebral I/R injuries and poststroke dementia. Recently, pyroptosis, a proinflammatory cell death, has been identified as a crucial pathological link of cerebral I/R injuries. However, whether pyroptosis acts as a trigger of Aβ accumulation after cerebral I/R has not yet been demonstrated. Blood-brain barrier (BBB) and glymphatic system mediated by aquaporin-4 (AQP-4) on astrocytic endfeet are important pathways for the clearance of Aβ in the brain, and pyroptosis especially occurring in astrocytes after cerebral I/R potentially damages BBB integrity and glymphatic function and thus influences Aβ clearance and brain homeostasis. In present study, the method of middle cerebral artery occlusion/reperfusion (MCAO/R) was used for building models of focal cerebral I/R injuries in rats. Then, we used lipopolysaccharide and glycine as the agonist and inhibitor of pyroptosis, respectively, Western blotting for detections of pyroptosis, AQP-4, and Aβ1-42 oligomers, laser confocal microscopy for observations of pyroptosis and Aβ locations, and immunohistochemical stainings of SMI 71 (a specific marker for BBB integrity)/AQP-4 and Nissl staining for evaluating, respectively, BBB-glymphatic system and neuronal damage. The results showed that pyroptosis obviously promoted the loss of BBB integrity and AQP-4 polarization, brain edema, Aβ accumulation, and the formation of Aβ1-42 oligomers and thus increased neuronal damage after cerebral I/R. However, glycine could inhibit cerebral I/R-induced pyroptosis by alleviating cytomembrane damage and downregulating expression levels of cleaved caspase-11/1, N-terminal gasdermin D, NLRP3 (nucleotide-binding domain, leucine-rich repeat containing protein 3), interleukin-6 (IL-6) and IL-1β and markedly abate above pathological changes. Our study revealed that pyroptosis is a considerable factor causing toxic Aβ accumulation, dysfunctional BBB-glymphatic system, and neurological deficits after cerebral I/R, suggesting that targeting pyroptosis is a potential strategy for the prevention of ischemic stroke sequelae including dementia.

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