scholarly journals Tissue Kallikrein Alleviates Cerebral Ischemia-Reperfusion Injury by Activating the B2R-ERK1/2-CREB-Bcl-2 Signaling Pathway in Diabetic Rats

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Ruifeng Shi ◽  
Kunxiong Yuan ◽  
Bin Hu ◽  
Hongfei Sang ◽  
Lizhi Zhou ◽  
...  

Diabetes mellitus (DM) substantially increases the risk of ischemic stroke and reduces the tolerance to ischemic insults. Tissue kallikrein (TK) has been demonstrated to protect neurons from ischemia/reperfusion (I/R) injury in orthoglycemic model by activating the bradykinin B2 receptor (B2R). Considering the differential effects of B2R or bradykinin B1 receptor (B1R) on cardioprotection and neuroprotection in I/R with or without diabetes, this study was designed to investigate the role of TK during cerebral I/R injury in streptozotocin-induced diabetic rats. Intravenous injection of TK inhibited apoptosis in neurons, alleviated edema and inflammatory reactions after focal cerebral I/R, significantly reduced the infarct volume, and improved functional recovery. These beneficial effects were accompanied by activation of the extracellular signal-regulated kinase 1/2 (ERK1/2), cAMP response element-binding (CREB), and Bcl-2 signal proteins. Inhibition of the B2R or ERK1/2 pathway abated the effects of TK, whereas an antagonist of B1R enhanced the effects. These findings reveal that the neuroprotective effect of TK against cerebral I/R injury in streptozotocin-induced diabetic rats mainly involves the enhancement of B2R and ERK1/2-CREB-Bcl-2 signaling pathway activity.

2021 ◽  
Vol 12 ◽  
Author(s):  
Wenjun Yan ◽  
Dongqing Ren ◽  
Xiaoxue Feng ◽  
Jinwen Huang ◽  
Dabin Wang ◽  
...  

Background: The incidence of cerebral ischemia disease leading cause of death in human population worldwide. Treatment of cerebral ischemia remains a clinical challenge for researchers and mechanisms of cerebral ischemia remain unknown. During the cerebral ischemia, inflammatory reaction and oxidative stress plays an important role. The current investigation scrutinized the neuroprotective and anti-inflammatory role of pterostilbene against cerebral ischemia in middle cerebral artery occlusion (MCAO) rodent model and explore the underlying mechanism.Methods: The rats were divided into following groups viz., normal, sham, MCAO and MCAO + pterostilbene (25 mg/kg) group, respectively. The groups received the oral administration of pterostilbene for 30 days followed by MCAO induction. The neurological score, brain water content, infarct volume and Evan blue leakage were estimated. Hepatic, renal, heart, inflammatory cytokines and inflammatory mediators were estimated.Results: Pterostilbene treatment significantly (p < 0.001) improved the body weight and suppressed the glucose level and brain weight. Pterostilbene significantly (p < 0.001) reduced the hepatic, renal and heart parameters. Pterostilbene significantly (p < 0.001) decreased the level of glutathione (GSH), glutathione peroxidase (GPx), superoxide dismutase (SOD) and decreased the level of malonaldehyde (MDA), 8-Hydroxy-2′-deoxyguanosine (8-OHdG). Pterostilbene significantly (p < 0.001) inflammatory cytokines and inflammatory parameters such as cyclooxygenase-2 (COX-2), inducible nitric oxidase synthase (iNOS) and prostaglandin (PGE2). Pterostilbene significantly (p < 0.001) down-regulated the level of metalloproteinases (MMP) such as MMP-2 and MMP-9. Pterostilbene suppressed the cellular swelling, cellular disintegration, macrophage infiltration, monocyte infiltration and polymorphonuclear leucocyte degranulation in the brain.Conclusion: In conclusion, Pterostilbene exhibited the neuroprotective effect against cerebral ischemia in rats via anti-inflammatory mechanism.


1997 ◽  
Vol 17 (10) ◽  
pp. 1048-1056 ◽  
Author(s):  
Jaroslaw Aronowski ◽  
Roger Strong ◽  
James C. Grotta

During reperfusion after ischemia, deleterious biochemical processes can be triggered that may antagonize the beneficial effects of reperfusion. Research into the understanding and treatment of reperfusion injury (RI) is an important objective in the new era of reperfusion therapy for stroke. To investigate RI, permanent and reversible unilateral middle cerebral artery/common carotid artery (MCA/CCA) occlusion (monitored by laser Doppler) of variable duration in Long-Evans (LE) and spontaneously hypertensive (SH) rats and unilateral MCA and bilateral CCA occlusion in selected LE rats was induced. In LE rats, infarct volume after 24 hours of permanent unilateral MCA/CCA occlusion was 31.1 ± 34.6 mm3 and was only 28% of the infarct volume after 120 to 300 minutes of reversible occlusion plus 24 hours of reperfusion, indicating that 72% of the damage of ischemia/reperfusion is produced by RI. When reversible ischemia was prolonged to 480 and 1080 minutes, infarct volume was 39.6 mm3 and 16.6 mm3, respectively, being indistinguishable from the damage produced by permanent ischemia and significantly smaller than damage after 120 to 300 minutes of ischemia. Reperfusion injury was not seen in SH rats or with bilateral CCA occlusion in LE rats, in which perfusion is reduced more profoundly. Reperfusion injury was ameliorated by the protein synthesis inhibitor cycloheximide or spin-trap agent N-tert-butyl-alpha-phenylnitrone pretreatment.


Stroke ◽  
2015 ◽  
Vol 46 (suppl_1) ◽  
Author(s):  
Kota Kurisu ◽  
Takeo Abumiya ◽  
Hideki Nakamura ◽  
Daisuke Shimbo ◽  
Ken Kazumata ◽  
...  

Background and Purpose: We previously presented the robust neuroprotective effects of post-ischemic trans-arterial regional hypothermia therapy in I/R injury model rats (ISC 2014, San Diego). This treatment showed a significant suppression of infarct volume and inflammatory reaction at 24hrs after reperfusion. To characterize the neuroprotective effects in terms of microvascular integrity, we investigated microvascular morphological changes and inflammatory reactions by a time course analysis within 24hrs. Methods: At reperfusion onset, 2hr-MCAO rats were divided into cold saline group (10°C, 20ml/kg of trans-arterial infusion from the recanalized artery for 15mins), warm saline group (37°C, in the same manner as cold saline group), and control group (recanalization only). Microvascular morphological changes were examined by vWF Immunohistochemistry (IHC) and transmission electron microscopy (TEM), and inflammatory reactions were examined by Western blotting and IHC at the time point of 0hr, 2hrs, 6hrs, and 24hrs of reperfusion. Results: IHC analysis and TEM observation revealed that astrocyte end-feet swelling occurred at 2hrs and progressed to 6hrs, and microvascular narrowing due to the swelling occurred at 6hrs in control group. This microvascular morphological change was attenuated in cold saline group. While endothelial ICAM1 overexpression started at 6hrs in control group, MPO, MMP9, and Iba-1 overexpression occurred only at 24hrs in the same group. These inflammatory reactions were also inhibited in cold saline group. Conclusions: Post-ischemic trans-arterial regional hypothermia therapy attenuated astrocyte end-feet swelling from 2hrs and the swelling induced microvascular narrowing at 6hrs. The treatment also inhibited endothelial ICAM-1 overexpression at 6hrs, and subsequently inhibited inflammatory reactions at 24hrs. The maintenance of microvascular morphological and functional integrity may be the primary cause of the neuroprotective effects by the regional hypothermia.


2016 ◽  
Vol 94 (11) ◽  
pp. 1187-1192 ◽  
Author(s):  
Mengyang Shui ◽  
Xiaoyan Liu ◽  
Yuanjun Zhu ◽  
Yinye Wang

Hydrogen sulfide (H2S), the third gas transmitter, has been proven to be neuroprotective in cerebral ischemic injury, but whether its effect is mediated by regulating autophagy is not yet clear. The present study was undertaken to explore the underlying mechanisms of exogenous H2S on autophagy regulation in cerebral ischemia. The effects and its connection with autophagy of NaHS, a H2S donor, were observed through neurological deficits and cerebral infarct volume in middle cerebral artery occlusion (MCAO) mice; autophagy-related proteins and autophagy complex levels in the ischemic hemisphere were detected with Western blot assay. Compared with the model group, NaHS significantly decreased infarct volume and improved neurological deficits; rapamycin, an autophagy activator, abolished the effect of NaHS; NaHS decreased the expression of LC3-II and up-regulated p62 expression in the ischemic cortex 24 h after ischemia. However, NaHS did not significantly influence Beclin-1 expression. H2S has a neuroprotective effect on ischemic injury in MCAO mice; this effect is associated with its influence in down-regulating autophagosome accumulation.


2020 ◽  
Author(s):  
Xiaowei Sun ◽  
Hao Liu ◽  
Zhongren Sun ◽  
Beng Zhang ◽  
Xinyu Wang ◽  
...  

Abstract Background: Acupuncture treatment possesses the neuroprotection potential to attenuate cerebral ischemia-reperfusion (I/R) injury. Endoplasmic reticulum (ER) stress has been suggested to be involved in the pathogenic mechanism of cerebral I/R injury. Whether acupuncture protects against cerebral I/R injury via regulating ER stress remains unclear. This study aimed to evaluate the role of ER stress in the neuroprotection of acupuncture against cerebral I/R injury and its underlying mechanisms. Methods: Cerebral I/R injury was induced by middle cerebral artery occlusion (MCAO) in rats. Acupuncture was carried out at Baihui (GV 20), Hegu (L14), and Taichong (Liv3) acupoints in rats immediately after reperfusion. The infarct volumes, neurological score, ER stress, autophagy and apoptosis were determined. Results: Acupuncture treatment decreased infarct volume, neurological score and suppressed ER stress via inactivation of ATF-6, PERK, and IRE1 pathways in MCAO rats. Attributing to ER stress suppression, 4-PBA (ER stress inhibitor) promoted the beneficial effect of acupuncture against cerebral I/R injury. Whereas, ER stress activator tunicamycin significantly counteracted the neuroprotective effects of acupuncture. In addition, acupuncture restrained autophagy via regulating ER stress in MCAO rats. Finally, ER stress took part in the neuroprotective effect of acupuncture against apoptosis in cerebral I/R injury. Conclusions: Our findings suggest that acupuncture offers neuroprotection against cerebral I/R injury, which is attributed to repressing ER stress-mediated autophagy and apoptosis.


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Danyun Fu ◽  
Haitong Liu ◽  
Jiang Zhu ◽  
Hongjiao Xu ◽  
Junyan Yao

Background. Cerebral ischemia-reperfusion (I/R) injury is the main cause of acute brain injury, which is a life-threatening disease due to the lack of effective treatments. [D-Ala2, D-Leu5] enkephalin (DADLE) is a synthetic delta-opioid receptor agonist that is reported to confer neuroprotective effect; however, the underlying mechanism is still being explored. The purpose of the present study is to determine whether DADLE administrated intracerebroventricularly could attenuate the cerebral I/R injury, to determine if this is through inhibiting the toll-like receptor 4 (TLR4)/nuclear factor kappa B (NF-κB) signaling pathway and therefore inhibiting neuroinflammation in an ischemic stroke model. Methods. Rats were subjected to 120 minutes of ischemia by transient middle cerebral artery occlusion (MCAO). At 45 minutes after ischemia, DADLE or control vehicle (artificial cerebrospinal fluid, ACSF) was given to the rats intracerebroventricularly. Neurological deficit, cerebral infarct volume, and histopathological changes were assessed at 24 hours after reperfusion. Brain inflammation was assessed by measuring tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in the ischemic penumbra by ELISA. The expression of TLR4 was determined by immunohistochemistry staining and western blotting. The expression of NF-κB was investigated by western blotting. Results. Compared with the vehicle-treatment (ACSF), DADEL improved neurological deficit ( 9.6 ± 2.1 versus 13.8 ± 1.9 ), reduced cerebral infarct volume ( 18.74 ± 3.30 % versus 10.57 ± 2.50 % ), and increased the number of normal neurons ( 29.72 ± 8.53 % versus 51.37 ± 9.18 % ) after cerebral I/R injury in rats (all P < 0.05 ). Expressions of inflammatory molecules including TNF-α and IL-6 were highly expressed in the vehicle-treated rats, whereas treatment with DADLE downregulated these expressions ( P < 0.05 ). Additionally, cerebral I/R injury significantly increased the TLR4 and NF-κB expression in vehicle-control group, which was markedly inhibited by DADLE ( P < 0.05 ). Conclusions. DADLE, administrated intracerebroventricularly at 45 minutes after cerebral ischemia, significantly ameliorated I/R-induced brain damage in rats. This kind of neuroprotective effect appears to be related to the downregulation of TLR4-mediated inflammatory responses.


2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Chi Xiao ◽  
Man-Li Xia ◽  
Jue Wang ◽  
Xin-Ru Zhou ◽  
Yang-Yun Lou ◽  
...  

Luteolin has been reported to attenuate ischemia/reperfusion (I/R) injury in the diabetic heart through endothelial nitric oxide synthase- (eNOS-) related antioxidative response. Though the nuclear factor erythroid 2-related factor 2 (Nrf2) is regarded as a key endogenous factor to reduce diabetic oxidative stress, whether luteolin reduces cardiac I/R injury in the diabetic heart via enhancing Nrf2 function needs to be clarified. We hypothesized that pretreatment with luteolin could alleviate cardiac I/R injury in the diabetic heart by affecting the eNOS/Nrf2 signaling pathway. The diabetic rat was produced by a single injection of streptozotocin (65 mg/kg, i.p.) for 6 weeks, and then, luteolin (100 mg/kg/day, i.g.), eNOS inhibitor L-NAME, or Nrf2 inhibitor brusatol was administered for the succedent 2 weeks. After that, the isolated rat heart was exposed to 30 min of global ischemia and 120 min of reperfusion to establish I/R injury. Luteolin markedly ameliorated cardiac function and myocardial viability; upregulated expressions of heme oxygenase-1, superoxide dismutase, glutathione peroxidase, and catalase; and reduced myocardial lactate dehydrogenase release, malondialdehyde, and 8-hydroxydeoxyguanosine in the diabetic I/R heart. All these ameliorating effects of luteolin were significantly reversed by L-NAME or brusatol. Luteolin also markedly reduced S-nitrosylation of Kelch-like ECH-associated protein 1 (Keap1) and upregulated Nrf2 and its transcriptional activity. This effect of luteolin on Keap1/Nrf2 signaling was attenuated by L-NAME. These data reveal that luteolin protects the diabetic heart against I/R injury by enhancing eNOS-mediated S-nitrosylation of Keap1, with subsequent upregulation of Nrf2 and the Nrf2-related antioxidative signaling pathway.


2019 ◽  
Vol 39 (1) ◽  
Author(s):  
Si Shi ◽  
Shaoqing Lei ◽  
Chaoliang Tang ◽  
Kai Wang ◽  
Zhongyuan Xia

AbstractBackground and aims: Diabetic kidney is more sensitive to ischemia/reperfusion (I/R) injury, which is associated with increased oxidative stress and impaired nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling. Melatonin, a hormone that is secreted with the rhythm of the light/dark cycle, has antioxidative effects in reducing acute kidney injury (AKI). However, the molecular mechanism of melatonin protection against kidney I/R injury in the state of diabetes is still unknown. In the present study, we hypothesized that melatonin attenuates renal I/R injury in diabetes by activating silent information regulator 2 associated protein 1 (SIRT1) expression and Nrf2/HO-1 signaling. Methods: Control or streptozotocin (STZ)-induced Type 1 diabetic rats were treated with or without melatonin for 4 weeks. Renal I/R injury was achieved by clamping both left and right renal pedicles for 30 min followed by reperfusion for 48 h. Results: Diabetic rats that were treated with melatonin undergoing I/R injury prevented renal injury from I/R, in aspects of the histopathological score, cell apoptosis, and oxidative stress in kidney, accompanied with decreased expressions of SIRT1, Nrf2, and HO-1 as compared with those in control rats. All these alterations were attenuated or prevented by melatonin treatment; but these beneficial effects of melatonin were abolished by selective inhibition of SIRT1 with EX527. Conclusion: These findings suggest melatonin could attenuate renal I/R injury in diabetes, possibly through improving SIRT1/Nrf2/HO-1 signaling.


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