Study on the Mechanism of Anti-Cerebral Ischemia-Reperfusion Injury of Ai Pian Based on Network Pharmacology and Metabolomics.

Microglial activation and induced inflammation play important roles in cerebral ischemia‒reperfusion injury (CIRI). Tanshinone IIA (Tan IIA) is a natural extract from Chinese herbal medicines that has anti-inflammatory, antioxidant, antiapoptotic and neuroprotective properties and has a protective effect against CIRI. This study aimed to investigate the effects of Tan IIA on microglial activation and inflammation under CIRI and the underlying molecular mechanism. Experimental investigations were conducted using rat and cellular models of CIRI induced by middle cerebral artery occlusion (MCAO) and oxygen‒glucose deprivation/reperfusion (OGD/R), respectively. The neuroprotective effects of Tan IIA on CIRI rats were evaluated through neurological deficit scores, TTC staining, and H&E staining. Immunofluorescence staining and ELISA were used to detect microglial activation and the expression of inflammatory molecules. In this study, treatment with Tan IIA significantly improved neurological deficits, reduced infarct size, and ameliorated pathological damage to the cerebral cortex in CIRI rats. It also decreased the expression of microglial marker Iba-1 and activation marker TSPO, as well as the expression of pro-inflammatory factors TNF-α, IL-1β and IL-6. In terms of molecular mechanisms, the expression of PANX1 and TGM2 is upregulated in this disease, and TGM2 binds to PANX1. The overexpression of PANX1 or TGM2 attenuated the inhibitory effect of Tan IIA on OGD/R-induced microglial activation and inflammation. Overall, Tan IIA inhibits the expression of PANX1 by downregulating TGM2 expression, thereby suppressing microglial activation and inflammation and alleviating CIRI. These findings provide new insights into the role of Tan IIA in the treatment of CIRI.

Background The dried roots of the Astragalus propinquus Schischkin (RAP) plant, as a traditional Chinese medicine, has been widely used to treat stroke, cerebral ischemia, qi deficiency, and hypertension. Buyang Huanwu decoction is traditionally used to treat stroke in China for more than 200 years and has a significant effect on cerebral ischemia, and RAP is monarch medicine of Buyang Huanwu decoction. Therefore, this study was designed to observe the regulatory effect of RAP on transmembrane iron transporters and ferroptosis-related factors in cerebral ischemia-reperfusion injury (CIRI) in rats. Methods Middle cerebral artery occlusion (MCAO) was used to block blood flow in the blood supply area of the middle cerebral artery in seventy male SD rats to induce focal CIRI to establish a rat model of CIRI. RAP was administered to explore the regulatory effect of RAP on iron transmembrane transport under the condition of CIRI. The infarct size was measured using 2,3,5-triphenyl-tetrazolium chloride (TTC) staining, the pathological structure of brain tissue was observed by HE staining, and neuronal injury was evaluated by Nissl staining after treatment. Then, changes in the iron transporters ferritin (Fn), ferritin heavy chain (FHC), ferritin light chain (FLC), transferrin (Tf), transferrin receptor (TfR), divalent metal transporter 1 (DMT1), L-type calcium channel (LTCC), transient receptor potential canonical 6 (TRPC6), and ferroportin 1 (FPN1) were observed by immunohistochemistry staining (IHC) and Western blotting. The expression of key factors of ferroptosis, including the membrane sodium-dependent cystine/glutamate antiporter System Xc− (System Xc−) light chain subunit (XCT) and heavy chain subunit (SLC3A2), glutathione peroxidase 4 (GPX4), nuclear factor erythroid 2-related factor (NRF2), heme oxygenase-1 (HO-1), and iron-responsive element-binding protein 2 (IREB2) in the brain tissues of rats was assessed by Western blotting. RAP decreased the infarct size and neuronal injury after CIRI in rats. Similarly, RAP treatment regulated the expression of iron transporters. As such, RAP was able to reduce the expression of Fn, FHC, FLC, Tf, TfR, DMT1, and TRPC6 and increase the expression of FPN1 through a Tf/TfR-independent pathway after CIRI in rats. Conclusion RAP stimulation inhibited ferroptosis by regulating the expression of the key ferroptosis factors XCT, SLC3A2, GPX4, NRF2, HO-1, and IREB2. In conclusion, RAP regulates transmembrane iron transport and ferroptosis to improve CIRI.

Cerebral ischemia-reperfusion injury (CIRI) occurs frequently clinically as a complication following cardiovascular resuscitation resulting in neuronal damage specifically to the hippocampal CA1 region with consequent cognitive impairment. Apoptosis and oxidative stress were proposed as major risk factors associated with CIRI development. Previously, glycosides obtained from Cistanche deserticola (CGs) were shown to play a key role in counteracting CIRI; however, the underlying mechanisms remain to be determined. This study aimed to investigate the neuroprotective effect of CGs on subsequent CIRI in rats. The model of CIRI was established for 2 hr and reperfusion for 24 hr by middle cerebral artery occlusion (MCAO) model. The MCAO rats were used to measure the antioxidant and anti-apoptotic effects of CGs on CIRI. Neurological function was evaluated by the Longa neurological function score test. 2,3,5-Triphenyltetrazolium chloride (TTC) staining was used to detect the area of cerebral infarction. Nissl staining was employed to observe neuronal morphology. TUNEL staining was used to detect neuronal apoptosis, while Western blot determined protein expression levels of factors for apoptosis-related and PI3K/AKT/Nrf2 signaling pathway. Data demonstrated that CGs treatment improved behavioral performance, brain injury, and enhanced antioxidant and anti-apoptosis in CIRI rats. In addition, CGs induced activation of PI3K/AKT/Nrf2 signaling pathway accompanied by inhibition of the expression of apoptosis-related factors. Evidence indicates that CGs amelioration of CIRI involves activation of the PI3K/AKT/Nrf2 signaling pathway associated with increased cellular viability suggesting these glycosides may be considered as an alternative compound for CIRI treatment.

To investigate the neuroprotective mechanism of mild hypothermia (MH) in ameliorating cerebral ischemia reperfusion (IR) injury. The Pulsinelli’s four-vessel ligation method was utilized to establish a rat model of global cerebral IR injury. To investigate the role of S100A8 in MH treatment of cerebral IR injury, hippocampus-specific S100A8 loss or gain of function was achieved using an adeno-associated virus system. We examined the effect of S100A8 over-expression or knock-down on the function of the SH-SY5Y cell line subjected to oxygen-glucose deprivation reoxygenation (OGDR) injury under MH treatment and delved into the underlying mechanisms. MH significantly ameliorates IR-induced neurological injury in the brain. Similarly to MH, knock-down of S100A8 significantly reduced neuronal oxidative stress, attenuated mitochondrial damage, inhibited apoptosis, and improved cognitive function in IR rats. Conversely, over-expression of S100A8 attenuated MH’s protective effect and aggravated brain IR injury. In vitro, low expression of S100A8 significantly inhibited the decline in mitochondrial membrane potential induced by OGDR, reduced oxidative stress response, and decreased cell apoptosis, acting as a protective agent nearly equivalent to MH in SH-SY5Y cells. However, over-expression of S100A8 significantly inhibited these protective effects of MH. Mechanistically, MH down-regulated S100A8 expression, enhancing mitochondrial function via activation of the CAMKK2/AMPK signaling pathway. Moreover, with MH treatment, the administration of CAMKK2 and AMPK inhibitors STO-609 and Dorsomorphin significantly increased oxidative stress, mitochondrial damage, and cell apoptosis, thereby diminishing MH’s neuroprotective effect against cerebral IR injury. Our study identified S100A8 as a master regulator that enables MH to ameliorate neurological injury during the early stage of cerebral IR injury by enhancing mitochondrial function. By targeting the S100A8-initiated CAMKK2/AMPK signaling pathway, we may unlock a novel therapeutic intervention or develop a refined MH therapeutic strategy against cerebral IR injury.

The objective of this study was to investigate the protective effect of notoginsenoside R1 (NGR1) on cerebral ischemia-reperfusion injury (CIRI) in rats, and its molecular mechanism, to provide new insights into the diagnosis and treatment of CIRI. Sixty Sprague-Dawley rats were randomly divided into four groups including the sham-operation group (Sham), cerebral ischemia-reperfusion model group (CIR), NGR1 treatment group (NGR1), and nimodipine positive control group (NDC) with 15 rats each. Bilateral common carotid arteries occlusion was used to establish the rat CIRI model. The area of cerebral infarction at the end of reperfusion was calculated by triphenyl tetrazolium chloride staining. Apoptosis of hippocampal neurons in each group was detected by Annexin V/propidium iodide double staining. Hippocampal expression of brain-derived neurotrophic factor (BDNF) mRNA, and Bcl-2 and Bax protein at the end of reperfusion were measured by RT-qPCR and western blot analysis, respectively. Data were analyzed by SPSS software analysis to ensure statistical significance. At the end of reperfusion, the area of cerebral infarction in the NGR1 and NDC groups was significantly smaller than that of the CIR group. Apoptosis analysis showed that compared with the CIR group, the apoptosis rate of hippocampal neurons was significantly decreased in the NGR1 and NDC groups. RT-qPCR and western blot analysis showed that at the end of reperfusion, higher levels of BDNF mRNA and the anti-apoptotic factor, Bcl-2, and lower levels of the pro-apoptotic factor, Bax, in the hippocampus were found in the NGR1 and NDC groups compared with the CIR group. The protective effect of NGR1 on CIRI was significantly stronger than that of nimodipine. In conclusion, NGR1 can reduce the area of cerebral infarction, reduce apoptosis of hippocampal neurons, and protect rats from CIRI. Those effects were achieved by activating the expression of BDNF and Bcl-2, and by inhibiting the expression of Bax.

Therapeutic Effect Analysis of Sinomenine on Rat Cerebral Ischemia–Reperfusion Injury

In the present study, the protective effects and regulatory mechanism of polysaccharide peptide (PSP) were investigated in rats with cerebral ischemia-reperfusion (IR) injury. Neuroblastoma N2a cells were divided into five groups: Negative control; IR injury; PSP low dose treatment; PSP middle dose treatment; and PSP high dose treatment. In vitro, the cell viability was detected by an MTT assay. ELISA was performed to determine the activity of lactate dehydrogenase (LDH) and caspase-3. A cerebral IR injury model in vivo was established, and hematoxylin and eosin (H&E) staining, western blotting, neurological deficit score and cerebral infarction were assessed. The cell viability was markedly improved following treatment with PSP and the activity of LDH and caspase-3 was decreased following PSP administration (P<0.05). The in vivo studies determined that the neurological deficit score and cerebral infarction volume were reduced with the concentration of PSP increasing between 150 and 250 mg/kg. The H&E staining indicated that PSP was able to protect the nerve cells against the cerebral IR injury. In addition, PSP upregulated the decreased silent information regulator protein 1, peroxisome proliferator-activated receptor γ coactivator-1α and apoptosis regulator B-cell lymphoma 2 expression induced by cerebral IR injury. The protein expression level of caspase-3 and apoptosis regulator apoptosis regulator Bcl-2-like protein 4 was downregulated following PSP administration. These results suggested that PSP may improve nerve cell viability, enhance the neuroprotective role in cerebral IR injury and provide a novel approach for the treatment of cerebral IR injury.

o explore the protective effect of chrysin on cerebral ischemia-reperfusion injury (CIRI) in rats and mechanisms. Fifty-four rats were divided into sham-operated, model and treatment groups. The treatment group was treated with 100 mg/kg chrysin for five days. Then, the CIRI model was established by middle cerebral artery occlusion in model and treatment groups. After modeling, compared with model group, in treatment group the neurological deficit score, brain water content and brain infarction percentage were decreased, the brain tissue superoxide dismutase level was increased, the malondialdehyde level was decreased, the nuclear factor-erythroid 2 related factor 2 and heme oxygenase-1 protein expression levels were increased, and the LC3-II and Beclin-1 protein levels were decreased (all p&lt;0.05). The chrysin pretreatment may alleviate the CIRI in rats by reduction of brain tissue oxidative stress and inhibition of excessive autophagy, the significant causes of morbidity and mortality in neurological disorders.

Differentially expressed genes induced by β-caryophyllene in a rat model of cerebral ischemia-reperfusion injury

To investigate the antioxidant effect of DJ-1 (Park7) in rats with cerebral ischemia/reperfusion (IR) injury and its potential mechanism. A total of 108 SD rats were randomly divided into sham-operated group, middle cerebral artery occlusion (MCAO) group, Scramble group, DJ-1 siRNA group, negative control (NC) group and DJ-1 overexpression group. Except for those in the sham group, all the rats were subjected to MCAO to establish models of cerebral IR injury. In DJ-1 siRNA and DJ-1 overexpression group, a DJ-1 siRNA and an adeno-associated virus vector carrying DJ-1 gene was injected into the lateral ventricle of the rats, respectively. In each group, neurological scores and brain water content were determined after the operation, and pathological changes of the brain tissue and neuronal injury in the cortical infarction area were assessed using HE and Nissl staining. Oxidative stress in the brain tissues was analyzed by detecting superoxide dismutase (SOD) and malondialdehyde (MDA). The expression levels of DJ-1, Nrf2, Ho-1 and NQO1 in the brain tissue were detected with Western blotting, and the expression and nucleation of Nrf2 was determined by immunofluorescence staining. Compared with those in MCAO group, the neurological scores (P < 0.001) and brain water content (P < 0.001) were significantly increased in DJ-1 siRNA group. Intracerebral injection of DJ-1 siRNA following MCAO obviously aggravated neuron injury in cerebral ischemia region, further reduced SOD activity and increased MDA content (P < 0.001), and significantly lowered the expression levels of Nrf2 and its downstream proteins HO-1 and NQO1 (P < 0.001). Intracerebral injection of the adenoviral vector for DJ-1 (P=0.003) overexpression significantly upregulated the levels of Nrf2 (P=0.006) and its downstream proteins HO-1 (P=0.004) and NQO1 (P=0.014). As an important neuroprotective factor, DJ-1 alleviates oxidative stress induced by cerebral IR injury in rats by activating the Nrf2 pathway.

Study on the pharmacodynamic effect of Rhizoma Dioscoreae polysaccharides on cerebral ischemia-reperfusion injury in rats and the possible mechanism

BackgroundThis study aims to investigate the regulation of herbal polysaccharide, Coriolus versicolor polysaccharides (CVP), on neuronal apoptosis in a rat cerebral ischemia-reperfusion injury (CIRI) model. We also intend to explore the mechanisms and effectiveness of CVP in the treatment of neuronal apoptosis in CIRI rats, including neurological function, cerebral infarction volume, inflammatory factors, and the p38 mitogen-activated protein kinase (p38MAPK) signaling pathway as well as its downstream protein cleaved-Caspase-3.MethodsA CIRI model was established in rats using the Longa method of middle cerebral artery occlusion. Neurological function scores and cerebral infarction volumes were measured in CIRI rats. Annexin V-fluorescein isothiocyanate (FITC) were used to measure neuronal apoptosis in CIRI rats. The levels of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in CIRI rats were determined using enzyme-linked immunosorbent assay (ELISA). A western blot assay was used to measure the protein expression levels of p38MAPK, phospho-p38MAPK (p-p38MAPK), Bcl-2, Bax and cleaved-Caspase-3 in brain tissue of CIRI rats.ResultsCVP can effectively improve the neurological function of rats after 6, 12, 24, and 48 h of CIRI. It can also improve the behavioral test, reduce the cerebral infarction volume and inhibit the apoptosis of nerve cells in CIRI rats. The protein expression levels of p-p38MAPK and cleaved-Caspase-3 exhibited a decreasing trend following CVP administration.ConclusionsCVP can significantly reduce the pathological characteristics of CIRI in rats and inhibit the apoptosis of nerve cells around the lesions. The mechanism of its effectiveness is related to inhibiting the activation of the p38MAPK signaling pathway.

Objective To explore the potential mechanism of acupuncture and moxibustion in the treatment of cerebral ischemia reperfusion injury (CIRI) using network pharmacology. Methods Firstly, the potential targets of acupuncture and moxibustion for CIRI were screened from the GEO database, and then the disease targets of CIRI were screened through data cleaning. Finally, the intersection between the disease targets of acupuncture and moxibustion for CIRI and the disease targets of CIRI were obtained, so as to obtain the key targets of acupuncture and moxibustion for CIRI. The Gene Ontology (GO) and The Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis were performed on these key targets. Results A total of 18804 potential CIRI targets, 370 CIRI disease targets and 152 key targets were obtained. GO and KEGG enrichment analysis of the key targets were performed to obtain the most significantly enriched GO entries and key pathways of the targets in cellular components, molecular functions and biological processes. Conclusion Acupuncture and moxibustion may treat CIRI by regulating calcium ion transport, postsynaptic organization and circadian entrainment.

Utilizing network pharmacology, molecular docking, and animal models to explore the therapeutic potential of the WenYang FuYuan recipe for cerebral ischemia-reperfusion injury through AGE-RAGE and NF-κB/p38MAPK signaling pathway modulation

To observe the effect of electroacupuncture (EA) and EA combined with intracerebral injection of vascular endothelial growth factor (VEGF) on endoplasmic reticulum stress (ERS) related proteins and genes as activating transcription factor (ATF 6), inositol requiring enzyme-1 (IRE 1), CCAAT/enhancer binding protein homologous protein (CHOP), X box-binding protein-1 (XBP 1) of cerebral ischemia reperfusion injury (CIRI) rats, so as to study its repair effect for CIRI. Forty male SD rats were equally and randomly divided into 5 groups: sham operation, model, EA, VEGF and EA+VEGF groups (n=8). The CIRI model was established by occlusion of the middle cerebral artery (MCAO) with thread embolism method. For rats of the sham operation group, the right common carotid artery was isolated without MCAO. EA (2 Hz/100 Hz, 1-3 mA) was applied to "Baihui" (GV 20), left "Quchi" (LI 11) and left "Zusanli" (ST 36) for 30 min, once a day for 14 days. For rats of the VEGF and EA+VEGF groups, 10 µL VEGF (0.025 µg/µL) was injected into the lateral ventricle 24 h after successful modeling. The rats' neurological function was assessed by using the modified neurological severity score (mNSS), and the histopathological changes of cerebral tissue were observed by Nissl staining method. The expression levels of ERS related proteins and genes ATF 6, IRE 1, XBP 1 and CHOP were determined by western blot (WB) and fluorescent quantitative PCR, separately. After modeling, the level of mNSS was significantly higher in the model group than in the sham operation group (P<0.05), and the number of Nissl bodies was markedly lower in the model group than in the sham operation group (P<0.05). Following the treatment, the mNSS was significantly lower in the EA, VEGF and EA+VEGF groups than in the model group (P<0.05), and the numbers of Nissl bodies were obviously higher in the EA, VEGF and EA+VEGF groups than in the model group (P<0.05), suggesting an improvement of neurological dysfunction and a repair of the injured cerebral tissue after the treatment. The levels of CIRI-induced increase of mNSS and CIRI-induced decrease of the number of Nissl bodies in the EA+VEGF group were respectively remarkably lower or higher than those of the simple EA and simple VEGF groups (P<0.05). WB and PCR showed that the expression levels of ATF 6, IRE 1, XBP1 and CHOP proteins and genes were notably higher in the model group than in the sham operation group (P<0.05), and considerably lower in the EA, VEGF and EA+VEGF groups than in the model group (P<0.05). Comparison among the three treatment groups showed that after the treatment, the expression levels of ATF 6, IRE 1, XBP1 and CHOP proteins and genes were obviously lower in the EA+VEGF group than in the EA and VEGF groups (P<0.05). EA and EA plus intracerebral microinjection of VEGF can improve neurological function and promote cerebral tissue repair in CIRI rats, which is associated with their effects in down-regulating the expression of ERS related proteins ATF 6, IRE 1, XBP1 and CHOP. The effect of EA+VEGF is superior to that of simple EA and simple VEGF.