scholarly journals Stargazin Interaction With Serine Racemase Mediates Cerebral Ischemia/Reperfusion Injury in Rats

Author(s):  
Xiaqing Yuan ◽  
Shanshan Diao ◽  
Shujun Chen ◽  
Jiajie Lu ◽  
Haitao Shen ◽  
...  

Abstract D-Serine is thought to be involved in N-methyl-D-aspartate (NMDA)-type glutamate receptor-mediated neurotoxicity and plays a pathophysiologic role in stroke. D-Serine is synthesized by serine racemase (SR), which directly converts L-serine into D-serine. The deletion of SR has been reported to protect against cerebral ischemia damage. Additionally, SR catalytic activity is physiologically regulated by its binding to stargazin. However, whether the stargazin-SR interaction affects the level of stroke damage remains elusive. We showed that cerebral ischemia increased the interaction of stargazin and SR and decreased the levels of D-serine. Disrupting the stargazin-SR interaction by knocking down stargazin aggravated cerebral ischemic insults. We found that cerebral ischemia decreased the phosphorylation of stargazin at the Thr-321 residue, which was phosphorylated by cAMP-dependent protein kinase A (PKA). Treatment with the PKA inhibitor H89 blocked stargazin T321 phosphorylation, augmented the stargazin-SR interaction, decreased D-serine levels, and alleviated focal cerebral ischemic damage in rats subjected to middle cerebral artery occlusion and reperfusion (MCAO/R). Thus, the stargazin-SR interaction is a promising strategy in the treatment of stroke.

2021 ◽  
Vol 15 ◽  
Author(s):  
Dazhuang Yi ◽  
Qunhui Wang ◽  
Yuhao Zhao ◽  
Yu Song ◽  
Hong You ◽  
...  

AimThis study was conducted in order to reveal the alterations in the N6-methyladenosine (m6A) modification profile of cerebral ischemia–reperfusion injury model rats.Materials and MethodsRats were used to establish the middle cerebral artery occlusion and reperfusion (MCAO/R) model. MeRIP-seq and RNA-seq were performed to identify differences in m6A methylation and gene expression. The expression of m6A methylation regulators was analyzed in three datasets and detected by quantitative real-time polymerase chain reaction, western blot, and immunofluorescence.ResultsWe identified 1,160 differentially expressed genes with hypermethylated or hypomethylated m6A modifications. The differentially expressed genes with hypermethylated m6A modifications were involved in the pathways associated with inflammation, while hypomethylated differentially expressed genes were related to neurons and nerve synapses. Among the m6A regulators, FTO was specifically localized in neurons and significantly downregulated after MCAO/R.ConclusionOur study provided an m6A transcriptome-wide map of the MACO/R rat samples, which might provide new insights into the mechanisms of cerebral ischemia–reperfusion injury.


2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Chenlu Mao ◽  
Cheng Hu ◽  
Yudi Zhou ◽  
Rong Zou ◽  
Sha Li ◽  
...  

Cerebral ischemia/reperfusion (I/R) injury can induce the mitophagy of neurons in the ischemic brain. Electroacupuncture (EA) pretreatment has a protective effect on cerebral ischemia/reperfusion injury. However, its internal mechanism still needs to be further studied. The present study’s purpose is to investigate whether mitophagy is involved in neuroprotection elicited by EA pretreatment in a rat model of cerebral ischemia/reperfusion injury. The rats were pretreated with vehicle, EA at the Baihui (GV20) and Shuigou (GV26) acupoints 30 min daily, for 5 days consecutively prior to the focal cerebral ischemia injury induced by the middle cerebral artery occlusion (MCAO) model. Compared to the sham group, the neurological scores, infarction volume, number of autophagosomes, FUNDC1, p62, and the ratio of LC3-II/I were significantly increased but mitochondrial membrane potential and autophagy-related protein p-mTORC1 significantly decreased in the I/R group. However, EA pretreatment significantly reversed these trends. Overall, the results of this study demonstrated that EA pretreatment protected the cerebral ischemia/reperfusion injury which maybe correlated with mitophagy.


Author(s):  
Ya-Juan Chen ◽  
Chen Chen ◽  
Meng-Yuan Li ◽  
Qing-Qing Li ◽  
Xiu-Juan Zhang ◽  
...  

AbstractFlavonoid glycoside scutellarin (SCU) has been widely applied in the treatment of cerebral ischemic diseases in China. In this article, we conducted research on the working mechanisms of SCU in hypoxia reoxygenation (HR) injury of isolated cerebral basilar artery (BA) and erebral ischemia reperfusion (CIR) injury in rat models. In isolated rat BA rings, HR causes endothelial dysfunction (ED) and acetylcholine (ACh) induces endothelium-dependent vasodilation. The myography result showed that SCU (100 µM) was able to significantly improve the endothelium-dependent vasodilation induced by Ach. However, SCU did not affect the ACh-induced relaxation in normal BA. Further studies suggested that SCU (10–1000 µM) dose-dependently induced relaxation in isolated BA rings which were significantly blocked by the cGMP dependent protein kinase (PKG) inhibitor Rp-8-Br-cGMPs (PKGI-rp, 4 µM). Pre-incubation with SCU (500 µM) reversed the impairment of endothelium-dependent vasodilation induced by HR, but the reversing effect was blocked if PKGI-rp (4 µM) was added. The brain slice staining test in rats’ model of middle cerebral artery occlusion (MCAO) induced CIR proved that the administration of SCU (45, 90 mg/kg, iv) significantly reduced the area of cerebral infarction. The Western blot assay result showed that SCU (45 mg/kg, iv) increased brain PKG activity and PKG protein level after CIR surgery. In conclusion, our findings suggested that SCU possesses the ability of protecting brain cells against CIR injury through vascular endothelium protection and PKG signal. Graphic Abstract


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Lin Guo ◽  
Zhixuan Huang ◽  
Lijuan Huang ◽  
Jia Liang ◽  
Peng Wang ◽  
...  

Abstract Background The incidence of ischemic stroke in the context of vascular disease is high, and the expression of growth-associated protein-43 (GAP43) increases when neurons are damaged or stimulated, especially in a rat model of middle cerebral artery occlusion/reperfusion (MCAO/R). Experimental design We bioengineered neuron-targeting exosomes (Exo) conjugated to a monoclonal antibody against GAP43 (mAb GAP43) to promote the targeted delivery of quercetin (Que) to ischemic neurons with high GAP43 expression and investigated the ability of Exo to treat cerebral ischemia by scavenging reactive oxygen species (ROS). Results Our results suggested that Que loaded mAb GAP43 conjugated exosomes (Que/mAb GAP43-Exo) can specifically target damaged neurons through the interaction between Exo-delivered mAb GAP43 and GAP43 expressed in damaged neurons and improve survival of neurons by inhibiting ROS production through the activation of the Nrf2/HO-1 pathway. The brain infarct volume is smaller, and neurological recovery is more markedly improved following Que/mAb GAP43-Exo treatment than following free Que or Que-carrying exosome (Que-Exo) treatment in a rat induced by MCAO/R. Conclusions Que/mAb GAP43-Exo may serve a promising dual targeting and therapeutic drug delivery system for alleviating cerebral ischemia/reperfusion injury.


FACETS ◽  
2019 ◽  
Vol 4 (1) ◽  
pp. 52-68 ◽  
Author(s):  
Mufzala Shamim ◽  
Nazish Iqbal Khan

The present study investigated the in vivo neuroprotective role of Panax ginseng extract (PGE) pretreatment against transient cerebral ischemia in a middle cerebral artery occlusion (MCAO) model. Rats were randomly divided as follows: group I, control; group II, sham-operated; group III, where animals were subjected to MCAO surgery; and group IV, where animals were orally administered 10 mL PGE per day (200 mg/kg of body weight per day) for 30 d followed by MCAO induction at day 31. Following 24 h of reperfusion, blood and tissue (brain, liver, and kidney) samples were collected for biochemical and histopathological examination. Biochemical testing included lipid profile, liver enzymes, kidney function tests, C-reactive protein (CRP), lactate dehydrogenase (LDH), glucose, and total protein estimation. Tissue antioxidants (catalase, superoxide dismutase, and glutathione) were assessed in brain, liver, and kidney tissues. MCAO-induced histopathological changes were also examined in the tissues. Pretreatment with PGE showed significant improvement in tissue antioxidant status in brain, liver and kidney tissues. PGE treatment maintains plasma lipid profile, liver enzymes, kidney function, and CRP, LDH, and glucose levels. Histologically, monocytes and macrophage infiltration were observed in the tissues of MCAO animals, whereas PGE treatment preserved tissue architecture and minimal monocyte infiltration. PGE supplementation showed a neuroprotective effect against ischemia–reperfusion injury by effectively increasing endogenous antioxidant enzyme activity.


2021 ◽  
Vol 12 ◽  
Author(s):  
Meiyao Wang ◽  
Yan Li ◽  
Renwei Zhang ◽  
Shuaimei Zhang ◽  
Hongliang Feng ◽  
...  

Objectives: This present study aimed to examine the effects of adiponectin-transfected endothelial progenitor cells (LV-APN-EPCs) on cerebral ischemia–reperfusion injury in rats with type 2 diabetes mellitus (T2DM) and to explore the underlying mechanisms.Methods: Seventy male Sprague–Dawley rats with T2DM were randomly divided into sham, phosphate-buffered saline (PBS), LV-APN-EPCs, LV-EPCs, and EPCs groups. Transient middle cerebral artery occlusion (MCAO) was induced by the intraluminal suture method. After 1 h of reperfusion, the five interventions were performed by tail-vein injections. The modified neurological severity score (mNSS) was used to assess neurological function before and on days 1, 7, and 14 after MCAO. After 14 days, magnetic resonance imaging scanning, hematoxylin and eosin staining, terminal dUTP nick-end labeling staining, Western blotting analysis, cluster of differentiation (CD) 31 immunofluorescence, and enzyme-linked immunosorbent assay were used to evaluate infarct rate, morphological damage, cell apoptosis, and microvessel density.Results: Compared with PBS, LV-EPCs, and EPCs groups, the LV-APN-EPCs group showed significantly lower mNSS score, lower infarct rate, and less morphological damage (all P < 0.05). In addition, compared with other groups, the LV-APN-EPCs group had significantly increased levels of B cell lymphoma/leukemia-2 (Bcl-2) protein, CD31+ microvessels, endothelial nitric oxide synthase, and vascular endothelial growth factor, and decreased levels of Bcl-2-associated X protein and neuronal apoptosis in the peri-infarct cortex (all P < 0.05).Conclusion: These results suggest that LV-APN-EPCs exert protective effects against cerebral ischemia–reperfusion injury in T2DM rats by increasing angiogenesis.


2018 ◽  
Vol 96 (6) ◽  
pp. 611-617 ◽  
Author(s):  
Bo Chu ◽  
Yadong Zhou ◽  
Heng Zhai ◽  
Lei Li ◽  
Li Sun ◽  
...  

MicroRNA-146a (miR-146a) is reportedly implicated in the pathogenesis of ischemia–reperfusion (I/R) injury; however, its role in cerebral I/R injury is unclear and requires further investigation. In this study, cerebral I/R injury was established in mice via middle cerebral artery occlusion, and the expression of miR-146a was detected in the brain tissue via quantitative real-time PCR. We found that the expression of miR-146a was upregulated. Furthermore, the endogenous miR-146a was antagonized by its specific inhibitor. The results indicated that the inhibition of miR-146a deteriorated I/R-induced neurobehavioral impairment, exaggerated the infarct size, and exacerbated blood–brain barrier leakage. Cerebral I/R injury-induced generation of inflammatory cytokines, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6, was further promoted by miR-146a inhibitor. The expression of interleukin-1 receptor associated kinase 1 (IRAK1), a target of miR-146a, was upregulated upon miR-146a inhibition. In addition, the nuclear factor κB (NF-κB) signaling pathway was over-activated when miR-146a was antagonized as manifested by the increased levels of phospho-NF-κB inhibitor α and nuclear p65. In summary, our findings demonstrate that the elevation of miR-146a may be one of the compensatory responses after the cerebral I/R injury and suggest miR-146a as a potential therapeutic target for cerebral I/R injury.


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