scholarly journals Preconditioning with L-alanyl-L-glutamine in a Mongolian Gerbil model of acute cerebral ischemia/reperfusion injury

2011 ◽  
Vol 26 (suppl 1) ◽  
pp. 14-20 ◽  
Author(s):  
Vilma Leite de Sousa Pires ◽  
José Reniclebson Feitosa de Souza ◽  
Sergio Botelho Guimarães ◽  
Antonio Ribeiro da Silva Filho ◽  
José Huygens Parente Garcia ◽  
...  

PURPOSE: To investigate the effect of L-alanyl-L-glutamine (L-Ala-Gln) preconditioning in an acute cerebral ischemia/reperfusion (I/R) model in gerbils. METHODS: Thirty-six Mongolian gerbils (Meriones unguiculatus), (60-100g), were randomized in 2 groups (n=18) and preconditioned with saline 2.0 ml (Group-S) or 0.75g/Kg of L-Ala-Gln, (Group-G) administered into the femoral vein 30 minutes prior to I/R. Each group was divided into three subgroups (n=6). Anesthetized animals (urethane, 1.5g/Kg, i.p.) were submitted to bilateral occlusion of common carotid arteries during 15 minutes. Samples (brain tissue and arterial blood) were collected at the end of ischemia (T0) and after 30 (T30) and 60 minutes (T60) for glucose, lactate, myeloperoxidase (MPO), thiobarbituric acid reactive substances (TBARS), glutathione (GSH) assays and histopathological evaluation. RESULTS: Glucose and lactate levels were not different in studied groups. However glycemia increased significantly in saline groups at the end of the reperfusion period. TBARS levels were significantly different, comparing treated (Group-G) and control group after 30 minutes of reperfusion (p<0.05) in cerebral tissue. Pretreatment with L-Ala-Gln promoted a significant increase in cerebral GSH contents in Group-G at T30 (p<0.001) time-point compared with Group-S. At T30 and T60, increased levels of GSH occurred in both time-points. There were no group differences regarding MPO levels. Pyknosis, presence of red neurons and intracellular edema were significantly smaller in Group-G. CONCLUSION: Preconditioning with L-Ala-Gln in gerbils submitted to cerebral ischemia/reperfusion reduces oxidative stress and degeneration of the nucleus (pyknosis) and cell death (red neurons) in the cerebral tissue.

2020 ◽  
Vol 11 ◽  
Author(s):  
Shu-Ying Xu ◽  
He-Qun Lv ◽  
Wen-Qian Li ◽  
Hao Hong ◽  
Yong-Jun Peng ◽  
...  

Background: Electroacupuncture (EA) treatment in ischemic stroke has been highlighted recently; however, the specific mechanism is still elusive. Autophagy is considered a new target for cerebral ischemia/reperfusion (I/R), but whether it plays a role of protecting or causing rapid cell apoptosis remains unclear. Studies have reported that the reduction in lysine 16 of histone H4 acetylation coheres with autophagy induction. The primary purpose of the study was to explore whether EA could alleviate I/R via autophagy-mediated histone H4 lysine 16 acetylation in the middle cerebral artery occlusion (MCAO) rat model.Methods: One hundred and twenty male Sprague-Dawley rats were divided into five groups: control group, MCAO group, MCAO+EA group, MCAO+EA+hMOF siRNA group, and MCAO+EA+Sirt1 inhibitor group. EA was applied to “Baihui” (Du20) and “Renzhong” (Du26) at 5 min after modeling and 16 h after the first EA intervention. The structure and molecular markers of the rat brain were evaluated.Results: EA significantly alleviated I/R injury by upregulating the expressions of Sirt1, Beclin1, and LC3-II and downregulating the expressions of hMOF and H4K16ac. In contrast, the Sirt1 inhibitor lowered the increase in Sirt1, Beclin1, and LC3-II and enhanced the level of hMOF and H4K16ac expressions associated with EA treatment. Besides, ChIP assay revealed that the binding of H4K16ac in the Beclin1 promoter region of the autophagy target gene was significantly raised in the MCAO+EA group and MCAO+EA+hMOF siRNA group.Conclusions: EA treatment inhibited the H4K16ac process, facilitated autophagy, and alleviated I/R injury. These findings suggested that regulating histone H4 lysine 16 acetylation-mediated autophagy may be a key mechanism of EA at Du20 and Du26 to treat I/R.


2015 ◽  
Vol 35 (4) ◽  
pp. 536-542 ◽  
Author(s):  
Fang Hua ◽  
Huiling Tang ◽  
Jun Wang ◽  
Megan C Prunty ◽  
Xiaodong Hua ◽  
...  

Toll-like receptor 4 (TLR4) contributes to cerebral ischemia/reperfusion (I/R) injury and is a potential target for the treatment of ischemic stroke. This experiment is to evaluate the effect of an exogenous TLR4 antagonist, TAK-242, against acute cerebral I/R injury. A mouse model of cerebral I/R was induced by transient middle cerebral artery occlusion. TAK-242 (3 mg/kg body weight) was injected intraperitoneally 1 hour after ischemia. Our results showed that the concentration of TAK-242 in plasma increased to 52.0 ng/mL 3 hours after injection, was maintained at 54.1 ng/mL 8 hours after injection, and decreased to 22.6 ng/mL 24 hours after injection. The concentration of TAK-242 in brain tissue increased to 26.1 ng/mL in ischemic hemisphere and 14.2 ng/mL in nonischemic hemisphere 3 hours after injection, and was maintained at the similar levels 24 hours after injection. We found that TAK-242 significantly reduced cerebral infarction compared with vehicle control, improved neurologic function, inhibited the phosphorylation of downstream protein kinases in TLR4 signaling pathway, and downregulated the expression of inflammatory cytokines. We conclude that TAK-242 is able to cross blood-brain barrier, blocks TLR4 signaling, mediates the expression of inflammatory cytokines, and protects the brain from acute damage induced by I/R.


2020 ◽  
Vol 98 (12) ◽  
pp. 855-860
Author(s):  
Yaping Zhang ◽  
Nan Ding ◽  
Hanlu Yi ◽  
Yudong Zhao ◽  
Zankai Ye ◽  
...  

The objective was to identify the differential expressed miRNA during cerebral ischemia–reperfusion injury (CIRI) process, thereby assisting in elucidating the mechanism of CIRI development and providing a potential target for CIRI prevention and treatment. Six mice were randomly assigned to two groups: control group and CIRI model group. A global cerebral IR model by four-vessel occlusion was prepared among the CIRI model group. Brain tissues were collected 48 h after reperfusion. Total RNA was extracted for each sample. miRNA microarrays were employed to detect the differentially expressed miRNA between the CIRI group and the control group. One differentially expressed miRNA was selected for verification by PCR. Compared with the control group, 69 miRNAs were significantly differential expressed in samples of the CIRI group, among which 50 miRNAs were upregulated and 19 miRNAs were downregulated. The real-time qPCR results indicated that the results of the miRNA microarray were reliable. A number of miRNAs were significantly regulated in the CIRI model, which suggested that miRNA was closely associated with the pathological alterations after ischemia. These identified miRNAs may provide directions and targets for the future pathological research of CIRI.


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