Puerarin protects the fatty liver from ischemia-reperfusion injury by regulating the PI3K/AKT signaling pathway

Abstract The incidence of non-alcoholic fatty liver (NAFLD) remains high, and many NAFLD patients suffer from severe ischemia-reperfusion injury (IRI). Currently, no practical approach can be used to treat IRI. Puerarin plays a vital role in treating multiple diseases, such as NAFLD, stroke, diabetes, and high blood pressure. However, its role in the IRI of the fatty liver is still unclear. We aimed to explore whether puerarin could protect the fatty liver from IRI. C57BL/6J mice were fed with a high‐fat diet (HFD) followed by ischemia reperfusion injury. We showed that hepatic IRI was more severe in the fatty liver compared with the normal liver, and puerarin could significantly protect the fatty liver against IRI and alleviate oxidative stress. The PI3K-AKT signaling pathway was activated during IRI, while liver steatosis decreased the level of activation. Puerarin significantly protected the fatty liver from IRI by reactivating the PI3K-AKT signaling pathway. However, LY294002, a PI3K-AKT inhibitor, attenuated the protective effect of puerarin. In conclusion, puerarin could significantly protect the fatty liver against IRI by activating the PI3K-AKT signaling pathway.

Breviscapine alleviates myocardial ischemia-reperfusion injury in diabetes rats

Purpose: To investigate the protective effect of breviscapine on myocardial ischemia-reperfusion injury (MIRI) in diabetes rats. Methods: Forty rats were divided into control, diabetes, MIRI of diabetes, and treatment groups. The MIRI of diabetes model was established in the latter two groups. Then, the treatment group was treated with 100 mg/kg breviscapine by intraperitoneal injection for 14 consecutive days. Results: After treatment, compared with MIRI of diabetes group, in treatment group the serum fasting blood glucose, fasting insulin, homeostasis model assessment of insulin resistance, and glycosylated hemoglobin levels decreased, the serum total cholesterol, triacylglycerol, and low-density lipoprotein cholesterol levels decreased, the serum high-density lipoprotein cholesterol level increased, the heart rate decreased, the mean arterial pressure, left ventricular ejection fraction, and fractional shortening increased, the serum cardiac troponin I, and creatine kinase-MB levels decreased, the myocardial tumor necrosis factor α and interleukin-6 levels decreased, the myocardial superoxide dismutase level increased, and the myocardial malondialdehyde level decreased (all P < 0.05). Conclusions: For treating MIRI of diabetes in rats, the breviscapine can reduce the blood glucose and lipid levels, improve the cardiac function, reduce the myocardial injury, and decrease the inflammatory response and oxidative stress, thus exerting the alleviating effect.

Geraniol attenuates cerebral ischemia-reperfusion injury in rats by regulating oxidative stress via Nrf2/HO-1 pathway / 中国药理学通报

Aim To investigate the regulatory effect of geraniol on Nrf2/HO-1 signaling pathway after cerebral ischemia-reperfusion(I/R)in rats. Methods In this experiment,all the male SD rats were randomly divided into nine groups receiving the following treatments:sham operation(sham); sham operation+200 mg·kg-1 geraniol; I/R; I/R+50 mg·kg-1 geraniol; I/R+100 mg/kg geraniol; I/R+200 mg·kg-1 geraniol; edaravone; I/R+ brusatol(Nrf2 inhibitor); I/R+200mg·kg-1 geraniol+brusatol. All rats received intraperitoneal injection of geraniol for five consecutive days before MCAO and again after MCAO. During the construction of cerebral I/R injury models,the blood vessels were isolated without any suture in the sham operation and the sham operation +200 mg·kg-1 geraniol groups while the blood vessels with suture in other groups. The damage of neurological function was evaluated by the modified rating scale for neurological function. The TTC,HE and Tunel staining methods were used to determine the cerebral infarction volume,the damage of the ischemic cortex and the apoptosis of cortical cells,respectively. The oxidative stress-related parameters then were measured. The protein expressions of Nrf2 and HO-1 were detected by immunohistochemical staining and the target protein expressions of the injured cortex were detected by Western blot. Results Compared with the model group,it was found that the geraniol treatment significantly repaired neural injury,reduced cerebral infarction volume,cerebral cortex damage and cell apoptosis. Meanwhile,geraniol intervention could significantly increase the expression of Nrf2/HO-1 protein in the right-sided cortex and reduce oxidative stress level. Conclusion Geraniol can attenuate cerebral injury induced by ischemia-reperfusion in rats via activating Nrf2/HO-1 signaling pathway.

Protective effect and mechanism of Longshengzhi capsules on cerebral ischemia-reperfusion injury in rats / 中国药房

OBJECTIVE To explore the protective effect and mechanism of Longshengzhi capsules on cerebral ischemia- reperfusion injury in rats. METHODS The model of middle cerebral artery occlusion （MCAO） was established by using the improved thread occlusion method. The experiment was divided into six groups： sham surgery group （only separating blood vessels without inserting thread plugs， given the same volume of normal saline）， model group （modeling， given the same volume of normal saline）， nimodipine group （positive control， modeling， dose of 20 mg/kg）， and low-dose， medium-dose， and high-dose groups of Longshengzhi capsules （modeling， doses of 0.72， 1.44 and 2.88 g/kg， respectively）， with 10 mice in each group. Each group was given corresponding medication solution/normal saline by gavage， once a day， for 7 consecutive days. One hour after the last administration， the Zea Longa scoring method was used to score the neurological deficits in each group of rats， and the ABC enzyme-linked immunosorbent assay was used to detect the serum levels of tumor necrosis factor-α （TNF-α） and interleukin-6 （IL-6） in rats； TTC staining was used to observe the volume of cerebral infarction in rats and calculate the cerebral infarction volume ratio. Hematoxylin eosin staining was used to observe the pathological changes in the brain tissue of rats. Immunohistochemical staining was used to detect the positive expression of NLRP3 protein in the brain tissue of rats. Real-time fluorescence quantitative PCR was used to detect mRNA relative expressions of Toll-like receptor 4 （TLR4） and nuclear factor-κB （NF-κB） in the brain tissue of rats. Western blot assay was adopted to detect the relative expressions of TLR4， NLRP3 and phosphorylated NF-κB （p-NF-κB） protein in the brain tissue of rats and its intracellular NF-κB protein. RESULTS Compared with the sham surgery group， the neural dysfunction score， serum levels of TNF-α and IL-6， cerebral infarction volume ratio， relative expression levels of NF-κB and TLR4 mRNA， as well as protein relative expressions of TLR4， NLRP3 and p-NF-κB in the brain tissue， and relative protein expression of intracellular NF-κB were increased significantly in the model group （P＜0.01）； the enlarged gap and significant edema were observed in cortical nerve cells of brain tissue in rats， with a large amount of inflammatory cell infiltration； the positive expression of NLRP3 protein in brain tissue of rats obviously increased. Compared with the model group， the levels of the above indicators in the medium-dose and high-dose groups of Longshengzhi capsules， as well as the Nimodipine group， were reversed to varying degrees， and most differences were statistically significant （P＜0.05 or P＜0.01）； the pathological morphology observation showed a significant improvement， and the positive expression of NLRP3 protein in the brain tissue of rats was obviously reduced. CONCLUSIONS Longshengzhi capsules may inhibit TLR4/NF-κB/NLRP3 signaling pathway and neuroinflammatory response， thereby achieving a protective effect against cerebral ischemia-reperfusion injury in rats.

Latest research and prospect of CD47 in kidney transplantation / 器官移植

CD47 is a transmembrane protein widely expressed on cell surface, which is considered as a key molecule for immune escape. With an increasing number of related studies, the role of CD47 and its ligands in immunomodulatory effects has been gradually understood. Recent studies have investigated the role of CD47 in ischemia-reperfusion injury of allogenetic kidney transplantation, rejection and xenotransplantation. Nevertheless, the specific role and the key mechanism remain elusive. In this article, the structure and function of CD47, common CD47 ligands, the relationship between CD47 and kidney transplantation, and the application of CD47 in kidney transplantation were reviewed, the latest research progress of CD47 in kidney transplantation was summarized, and the limitations of current research and subsequent research direction were analyzed, aiming to provide reference for subsequent application of CD47 in allogeneic and kidney xenotransplantation.

Down-regulating XBP1s alleviates hypoxia/reoxygenation injury of renal tubular epithelial cells by inhibiting ITPR-mediated mitochondrial dysfunction / 器官移植

Objective To evaluate the effect of spliced X-box binding protein 1 (XBP1s) on hypoxia/reoxygenation (H/R) injury of mouse renal tubular epithelial cells and unravel underlying mechanism. Methods Mouse renal tubular epithelial cells were divided into adenovirus negative control group (Ad-shNC group), targeted silencing XBP1s adenovirus group (Ad-shXBP1s group), Ad-shNC+H/R group and Ad-shXBP1s+H/R group. The apoptosis level, mitochondrial reactive oxygen activity, mitochondrial membrane potential and mitochondrial calcium ion level were detected in each group. Chromatin immunocoprecipitation followed by sequencing (ChIP-seq) was employed to analyze the binding sites of XBP1s in regulating the inositol 1,4,5-trisphosphate receptor (ITPR) family. The expression levels of XBP1s and ITPR family messenger RNA (mRNA) and protein were determined in each group. Results Compared with the Ad-shNC group, the apoptosis level was higher, mitochondrial reactive oxygen species level was increased, mitochondrial membrane potential was decreased and mitochondrial calcium ion level was elevated in the Ad-shNC+H/R group. Compared with the Ad-shNC+H/R group, the apoptosis level was lower, mitochondrial reactive oxygen species level was decreased, mitochondrial membrane potential was elevated, and mitochondrial calcium ion level was decreased in the Ad-shXBP1s+H/R group (all P<0.05). Compared with the Ad-shNC group, relative expression levels of XBP1s, ITPR1, ITPR2 and ITPR3 mRNAs and proteins were down-regulated in the Ad-shXBP1s group (all P<0.05). Compared with the Ad-shNC group, relative expression levels of XBP1s, ITPR1, ITPR2 and ITPR3 proteins were up-regulated in the Ad-shNC+H/R group. Compared with the Ad-shNC+H/R group, relative expression levels of XBP1s, ITPR1, ITPR2 and ITPR3 were down-regulated in the Ad-shXBP1s+H/R group (all P<0.05). ChIP-seq results showed that XBP1s could bind to the promoter and exon of ITPR1, the exon of ITPR2, and the exon of ITPR3. Conclusions XBP1s may affect mitochondria-associated endoplasmic reticulum membrane structure and function by directly regulating ITPR transcription and translation. Down-regulating XBP1s may inhibit ITPR expression and mitigate mitochondrial damage.

Shuangshen Ningxin Capsules Regulates Mitochondrial Fission and Fusion to Alleviate Myocardial Ischemia-reperfusion Injury in Rats / 中国实验方剂学杂志

ObjectiveTo explore whether the mechanism of Shuangshen Ningxin capsules （SSNX） in alleviating myocardial ischemia-reperfusion injury （MIRI） in rats is related to the regulation of mitochondrial fission and fusion. MethodThis study focused on Sprague Dawley （SD） rats and ligated the left anterior descending branch of the coronary artery to construct a rat model of MIRI. The rats were divided into the sham operation group， model group， SSNX group （90 mg·kg-1） and trimetazidine group （5.4 mg·kg-1）. The activity of superoxide dismutase （SOD） and the content of malondialdehyde （MDA） were detected by micro method. Changes in mitochondrial membrane potential （△Ψm） and the degree of mitochondrial permeability transition pore （mPTP） opening were detected by the chemical fluorescence method. The intracellular adenosine triphosphate （ATP） level was detected by the luciferase assay. The messenger ribonucleic acid （mRNA） and protein expression levels of mitochondrial fission and fusion related factors dynamin-related protein 1 （DRP1）， mitochondrial fission 1 protein （FIS1）， optic atrophy protein 1 （OPA1）， mitochondrial outer membrane fusion protein 1 （MFN1）， and MFN2 were detected by real-time polymerase chain reaction （real-time PCR） and Western blot. ResultCompared with the sham operation group， the model group showed a decrease in serum SOD activity and an increase in MDA content. The opening level of mPTP， the level of △Ψm and ATP content decreased， the protein expressions of mitochondrial fission factors DRP1 and FIS1 increased， and the protein expressions and mRNA transcription levels of fusion related factors OPA1 and MFN1 decreased. Compared with the model group，SSNX significantly increased serum SOD activity， reduced MDA content， increased intracellular ATP level and △Ψm， reduced the opening level of mPTP， downregulated the protein expressions of mitochondrial fission factors DRP1 and FIS1， and increased the mRNA transcription levels and protein expressions of fusion related factors OPA1 and MFN1. ConclusionSSNX inhibits the expressions of mitochondrial fission factors DRP1 and FIS1， and increases the expressions of fusion related factors OPA1 and MFN1， inhibiting mitochondrial fission and increasing mitochondrial fusion， thereby alleviating MIRI.

MiRNA Regulating Autophagy Signaling Pathway Induced by Cerebral Ischemia/Reperfusion / 中山大学学报(医学科学版)

Ischemia and hypoxia cause functional damage to brain tissues during stroke， and when blood supply is restored to brain tissues after ischemia， a large number of free radicals and calcium overload cause cerebral ischemia-reperfusion injury， which further aggravates the condition. Autophagy is a self-protection mechanism that maintains the homeostasis of the intracellular environment， but excessive autophagy causes brain tissue damage. MiRNA is a small endogenous non-coding RNA molecule that regulate various physiological activities at the gene level by binding to complementary sequences in the 3 '- UTR of its target gene mRNA， leading to translation inhibition or mRNA degradation. MiRNA not only directly acts on autophagy related proteins， but also participates in autophagy regulation induced by ischemia/reperfusion through various signaling pathways. However， there is still a lack of systematic induction and analysis of miRNA regulation of autophagy signaling pathways induced by cerebral ischemia/reperfusion. This article reviews the regulation of cellular autophagy during cerebral ischemia/ reperfusion by miRNA-124， miRNA-298， miRNA-202-5p， miRNA-142， miRNA-26b and so on through different signaling pathways， providing a systematic and theoretical approach for the study of autophagy in stroke.

Treatment of Cerebral Ischemia-reperfusion Injury by Traditional Chinese Medicine Based on PI3K/Akt Signaling Pathway： A Review / 中国实验方剂学杂志

Cerebral ischemia/reperfusion injury （CIRI） is a complex cascade reaction process in which the blood flow and oxygen supply of brain tissue in the infarcted area recover after cerebral ischemia， resulting in secondary injury of ischemic brain tissue. At present， thrombolysis as soon as possible and restoration of cerebral blood supply are still the only strategies for the treatment of stroke， but a considerable number of patients' symptoms will be more serious after reperfusion， making patients face adverse outcomes such as neurological function injury and even death and seriously affecting the quality of life and safety of patients. Therefore， an in-depth exploration of the mechanism and treatment strategy of CIRI has important clinical significance. The phosphatidylinositol 3- kinase （PI3K）/protein kinase B （Akt） signaling pathway is one of the classic anti-apoptosis/reproductive-promoting signal transduction pathways， which is responsible for cell proliferation， growth， and differentiation. It is the key cascade signaling pathway of CIRI， located at the core site in many mechanisms such as mitochondrial disorder， apoptosis， autophagy， oxidative stress， and inflammation. It is closely related to the occurrence and development of CIRI. Traditional Chinese medicine has been used in the clinical treatment of stroke and its complications for thousands of years， and the clinical effect of traditional Chinese medicine in the prevention and treatment of CIRI has been affirmed by a large number of research results in recent years. It is further clarified that the monomers， active components， and their compound prescriptions of traditional Chinese medicine can directly or indirectly regulate the PI3K/Akt signaling pathway by virtue of the biological advantages of multi-targets， multi-components， and multi-pathways and play an overall protective role in CIRI. By analyzing the related research progress of traditional Chinese medicine in China and abroad in recent years， the authors summarized the role and mechanism of regulating the PI3K/Akt signaling pathway in the prevention and treatment of CIRI， so as to provide further theoretical basis for the study of the mechanism of clinical prevention and treatment of CIRI.

Efficacy of partial and complete resuscitative endovascular balloon occlusion of the aorta in the hemorrhagic shock model of liver injury / 世界急诊医学杂志（英文）

@#BACKGROUND: Resuscitative endovascular balloon occlusion of the aorta (REBOA) can temporarily control traumatic bleeding. However, its prolonged use potentially leads to ischemia-reperfusion injury (IRI). Partial REBOA (pREBOA) can alleviate ischemic burden; however, its security and effectiveness prior to operative hemorrhage control remains unknown. Hence, we aimed to estimate the efficacy of pREBOA in a swine model of liver injury using an experimental sliding-chamber ballistic gun. METHODS: Twenty Landrace pigs were randomized into control (no aortic occlusion) (n=5), intervention with complete REBOA (cREBOA) (n=5), continuous pREBOA (C-pREBOA) (n=5), and sequential pREBOA (S-pREBOA) (n=5) groups. In the cREBOA and C-pREBOA groups, the balloon was inflated for 60 min. The hemodynamic and laboratory values were compared at various observation time points. Tissue samples immediately after animal euthanasia from the myocardium, liver, kidneys, and duodenum were collected for histological assessment using hematoxylin and eosin staining. RESULTS: Compared with the control group, the survival rate of the REBOA groups was prominently improved (all P<0.05). The total volume of blood loss was markedly lower in the cREBOA group (493.14±127.31 mL) compared with other groups (P<0.01). The pH was significantly lower at 180 min in the cREBOA and S-pREBOA groups (P<0.05). At 120 min, the S-pREBOA group showed higher alanine aminotransferase (P<0.05) but lower blood urea nitrogen compared with the cREBOA group (P<0.05). CONCLUSION: In this trauma model with liver injury, a 60-minute pREBOA resulted in improved survival rate and was effective in maintaining reliable aortic pressure, despite persistent hemorrhage. Extended tolerance time for aortic occlusion in Zone I for non-compressible torso hemorrhage was feasible with both continuous partial and sequential partial measures, and the significant improvement in the severity of acidosis and distal organ injury was observed in the sequential pREBOA.

Evolution and innovation of preservation fluid for donor liver / 器官移植

Organ preservation fluid could mitigate cold ischemia injury and maintain normal function of the grafts. At present, how to reduce a series of injury caused by cold ischemia of donor liver and improve the preservation quality of grafts are the hot and challenging spots in this field. Currently, preservation fluid in clinical practice has not achieved ideal preservation effect, especially for the protection of marginal donor organs. In the context of severe donor shortage, the key solution is still to explore the optimal preservation protocol for donor liver to prevent grafts from cold ischemia injury. In this article, the mechanism of donor liver injury during cold ischemia, the classification and evolution of donor liver preservation fluid were summarized, the development direction and challenges of donor liver preservation fluid were discussed, aiming to provide novel ideas and references for the research and development of donor liver preservation fluid.

Construction of competitive endogenous RNA network mediated by lung ischemia-reperfusion core genes / 器官移植

Objective To analyze the core genes of lung ischemia-reperfusion injury and construct a competitive endogenous RNA (ceRNA) network. Methods Original data of GSE145989 were downloaded from the Gene Expression Omnibus (GEO) database as the training set, and the GSE172222 and GSE9634 datasets were used as the validation sets, and the differentially-expressed genes (DEG) were identified. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were performed. Protein-protein interaction (PPI) network was constructed, and the core genes were screened, and the diagnostic values of these core genes and the immune infiltration levels of immune cells were evaluated. The ceRNA network was constructed and validated. The targeted drugs based on ceRNA network were assessed. Results A total of 179 DEG were identified, including 61 down-regulated and 118 up-regulated genes. GO analysis showed that DEGs were associated with multiple biological processes, such as cell migration, differentiation and regulation, etc. They were correlated with cell components, such as vesicle membrane, serosa and membrane raft, etc. They were also associated with multiple molecular functions, such as chemokine receptor, G protein-coupled receptor, immune receptor activity and antigen binding, etc. KEGG pathway enrichment analysis revealed that DEG were involved in tumor necrosis factor (TNF), Wnt, interleukin (IL)-17 and nuclear factor (NF)-κB signaling pathways, etc. PPI network suggested that CD8A, IL2RG, STAT1, CD3G and SYK were the core genes of lung ischemia-reperfusion injury. The ceRNA network prompted that miR-146a-3p, miR-28-5p and miR-593-3p were related to the expression level of CD3G. The miR-149-3p, miR-342-5p, miR-873-5p and miR-491-5p were correlated with the expression level of IL-2RG. The miR-194-3p, miR-512-3p, miR-377-3p and miR-590-3p were associated with the expression level of SYK. The miR-590-3p and miR-875-3p were related to the expression level of CD8A. The miR-143-5p, miR-1231, miR-590-3p and miR-875-3p were associated with the expression level of STAT1. There were 13 targeted drugs for CD3G, 4 targeted drugs for IL-2RG, 28 targeted drugs for SYK and 3 targeted drugs for lncRNA MUC2. No targeted drugs were identified for CD8A, STAT1 and other ceRNA network genes. Conclusions CD8A, IL2RG, STAT1, CD3G and SYK are the core genes of lung ischemia-reperfusion injury. The research and analysis of these core genes probably contribute to the diagnosis of lung ischemia-reperfusion injury and providing novel research ideas and therapeutic targets.

Down-regulation of XBP1s alleviates the senescence of renal tubular epithelial cells induced by hypoxia/reoxygenation through Sirt3/SOD2/mtROS signaling pathway / 器官移植

Objective To investigate the role and mechanism of spliced X-box binding protein 1 (XBP1s) in the senescence of primary renal tubular epithelial cells induced by hypoxia/reoxygenation (H/R). Methods Primary renal tubular epithelial cells were divided into the normal control group (NC group), H/R group, empty adenovirus negative control group (Ad-shNC group), targeted silencing XBP1s adenovirus group (Ad-shXBP1s group), empty adenovirus+H/R treatment group (Ad-shNC+H/R group) and targeted silencing XBP1s adenovirus+H/R treatment group (Ad-shXBP1s +H/R group), respectively. The expression levels of XBP1s in the NC, H/R, Ad-shNC and Ad-shXBP1s groups were measured. The number of cells stained with β-galactosidase, the expression levels of cell aging markers including p53, p21 and γH2AX, and the levels of reactive oxygen species (ROS), malondialdehyde (MDA) and superoxide dismutase (SOD) were determined in the Ad-shNC, Ad-shNC+H/R and Ad-shXBP1s+H/R groups. Chromatin immunoprecipitation was employed to verify Sirtuin 3 (Sirt3) of XBP1s transcription regulation, and the expression levels of Sirt3 and downstream SOD2 after down-regulation of XBP1s were detected. Mitochondrial reactive oxygen species (mtROS) were detected by flow cytometry. Results Compared with the NC group, the expression level of XBP1s was up-regulated in the H/R group. Compared with the Ad-shNC group, the expression level of XBP1s was down-regulated in the Ad-shXBP1s group (both P<0.001). Compared with the Ad-shNC group, the number of cells stained with β-galactosidase was increased, the expression levels of p53, p21 and γH2AX were up-regulated, the levels of ROS, MDA and mtROS were increased, the SOD activity was decreased, the expression level of Sirt3 was down-regulated, and the ratio of Ac-SOD2/SOD2 was increased in the Ad-shNC+H/R group. Compared with the Ad-shNC+H/R group, the number of cells stained with β-galactosidase was decreased, the expression levels of p53, p21 and γH2AX were down-regulated, the levels of ROS, MDA and mtROS were decreased, the SOD activity was increased, the expression level of Sirt3 was up-regulated and the ratio of Ac-SOD2/SOD2 was decreased in the Ad-shXBP1s+H/R group (all P<0.05). Conclusions Down-regulation of XBP1s may ameliorate the senescence of primary renal tubular epithelial cells induced by H/R, which probably plays a role through the Sirt3/SOD2/mtROS signaling pathway.

Research progress on association between macrophages and ischemia-reperfusion injury / 器官移植

Ischemia-reperfusion injury (IRI) is an extremely complicated pathophysiological process, which may occur during the process of myocardial infarction, stroke, organ transplantation and temporary interruption of blood flow during surgery, etc. As key molecules of immune system, macrophages play a vital role in the pathogenesis of IRI. M1 macrophages are pro-inflammatory cells and participate in the elimination of pathogens. M2 macrophages exert anti-inflammatory effect and participate in tissue repair and remodeling and extracellular matrix remodeling. The balance between macrophage phenotypes is of significance for the outcome and treatment of IRI. This article reviewed the role of macrophages in IRI, including the balance between M1/M2 macrophage phenotype, the mechanism of infiltration and recruitment into different ischemic tissues. In addition, the potential therapeutic strategies of targeting macrophages during IRI were also discussed, aiming to provide reference for alleviating IRI and promoting tissue repair.

Research progress of traditional Chinese medicine in regulating Nrf2/HO-1 signaling pathway to interfere with myocardial ischemia-reperfusion injury / 中国药房

Myocardial ischemia-reperfusion injury （MIRI） is a serious complication of revascularization in patients with myocardial infarction. The nuclear factor erythroid 2-related factor 2 （Nrf2）/heme oxygenase-1 （HO-1） signaling pathway plays an important role in the pathological process of MIRI. Currently，research has found that traditional Chinese medicine has a good effect on myocardial injury caused by ischemia-reperfusion. Based on the Nrf2/HO-1 signaling pathway，this article summarizes the action mechanism of traditional Chinese medicine formulas and monomers in intervening with MIRI. It is found that traditional Chinese medicine formulas （Yixin formula，Wenyang tongmai formula，Dingxin formula Ⅰ），monomers such as terpenoids （ginkgolides， astragaloside Ⅳ，ginsenosides），phenols （brazilin，hematoxylin A，resveratrol） and quinones （aloe，emodin） can alleviate MIRI by activating the Nrf2/HO-1 signaling pathway，inhibiting oxidative stress and inflammatory reactions，etc.

Precondicionamiento Isquémico Remoto: bases de la protección y resultados clínicos

El precondicionamiento isquémico remoto es una manera eficaz de disminuir el daño por isquemia y reperfusión en el corazón y otros órganos como cerebro o riñón, en modelos experimentales. Este consiste en realizar entre 3 y 5 ciclos de 5 minutos de isquemia seguidos del mismo tiempo de reperfusión, en un tejido alejado del que se quiere proteger, normalmente una extremidad. Estudios preclínicos en animales indican que la isquemia precondicionante inicia señales nerviosas y humorales en el tejido isquémico remoto, que en el corazón activan mecanismos de protección. La señal nerviosa se origina en fibras sensoriales que a nivel cerebral producen una activación del sistema parasimpático. El nervio vago activa ganglios cardíacos intrínsecos del corazón lo que induce protección. Además, desde el tejido isquémico se liberan a la circulación diferentes mediadores que viajan en forma libre o en vesículas lipídicas (exosomas) que inician vías de señalización protectoras en el corazón. A pesar del éxito del precondicionamiento isquémico remoto en animales de experimentación, su aplicación en seres humanos no ha tenido resultados claros. Esta discrepancia puede deberse a una diversidad de factores tales como la edad, la existencia de otras patologías, uso de fármacos u otros tratamientos que afectan la respuesta de los pacientes. Se requiere un mayor conocimiento de las bases moleculares de este mecanismo de protección para que su aplicación en clínica sea exitosa.

In experimental models, remote ischemic preconditioning effectively decreases ischemia reperfusion injury to the heart and other organs such as the brain or kidney. It consists of 3 to 5 cycles of 5 minutes of ischemia followed by 5 minutes of reperfusion, in a remote tissue, usually a limb. Preclinical studies in animals indicate that preconditioning ischemia initiates neural and humoral signals in the remote ischemic tissue, which activate protective mechanisms in the heart. The nervous signal originates in sensory fibers that activate the parasympathetic system in the brain. The vagus nerve activates the intrinsic cardiac ganglia of the heart, leading to protection from ischemic injury. Furthermore, mediators are released from the ischemic tissue into the circulation that travels freely or in lipid vesicles (exosomes) to the heart where they initiate protective signaling pathways. Despite the success of remote ischemic preconditioning in experimental animals, its application in humans has not produced clear results. This discrepancy may be due to a variety of factors such as age, the existence of other pathologic processes, or the use of drugs or other treatments that affect the patient´s response. An increased knowledge of the molecular bases of this protective mechanism is required for its clinical application to be successful.

Vitamin A could be a Therapeutic Agent in Ischemia/Reperfusion Induced Kidney Injury / La vitamina A podría ser un agente terapéutico en la lesión renal inducida por isquemia/reperfusión

ABSTRACT Introduction: Renal ischemia (I) could develop due to decreased or ceased blood flow to the kidney in some clinical conditions such as shock, sepsis, and kidney transplantation. The re-supply of blood to the kidney is called reperfusion (R). Ischemia and reperfusion periods can cause severe kidney damage. Objectives: When we examined the I/R molecular progression, antioxidant molecules such as vitamin A seem promising treatment agents. This study aimed to investigate the effects of vitamin A on renal I/R injury. Material and Methods: In the study, 40 Sprague-Dawley male rats were divided into five groups (n=8): the control group, only I/R, I/R+1000, I/R+3000, and I/R+9000 IU/kg of Vitamin A groups. Vitamin A was administrated to each group for seven days via oral gavage. Blood and kidney tissue samples were collected at the end of the experiment. We took blood samples for Superoxide dismutase (SOD), malondialdehyde (MDA), catalase (CAT), blood urea nitrogen (BUN), and creatinine (Cr) levels, and determined their values. The tissue samples were stained with hematoxylin/eosin to examine the renal changes histopathologically and stereologically under a light microscope. Results: Histopathological changes caused by I/R were decreased with vitamin A administration in a dose-dependent manner (p<0.05). Vitamin A administration decreased MDA levels and increased SOD and CAT activities (p<0.05). The most effective dose among treatment groups was 9000 IU/kg. There was no significant difference between the controls and all other groups regarding BUN and Cr concentrations. Conclusions: Consequently, administration of vitamin A after renal I/R reduced the histological damage and ameliorated the antioxidant state. These results showed that vitamin A could be a promising agent in treating I/R-induced acute kidney injury.

RESUMEN Introducción: La isquemia renal (I) puede desarrollarse debido a la disminución o interrupción del flujo sanguíneo al riñón en algunas condiciones clínicas como shock, sepsis y trasplante renal. El reabastecimiento de sangre al riñón se denomina reperfusión (R). Tanto la isquemia como los períodos de reperfusión pueden causar graves daños renales. Objetivos: Cuando examinamos la progresión molecular I/R, las moléculas antioxidantes como la vitamina A parecen agentes de tratamiento prometedores. El objetivo de este estudio fue investigar los efectos de la vitamina A sobre la lesión renal I/R. Material y Métodos: En el estudio, 40 ratas macho Sprague-Dawley se dividieron en 5 grupos (n=8) como: control, solo I/R, I/R+1000, I/R+3000 e I/R+9000 UI/kg de la Vitamina A. La vitamina A se administró a cada grupo durante 7 días por vía oral forzada. Al final del experimento se recolectaron muestras de sangre y tejido del riñón. A partir de muestras de sangre se determinaron los niveles de superóxido dismutasa (SOD), malondialdehído (MDA), catalasa (CAT), nitrógeno ureico en sangre (BUN) y creatinina (Cr). Las muestras de tejido se tiñeron con hematoxilina/eosina y los cambios en la histología renal se examinaron histopatológicamente y estereológicamente al microscopio de luz. Resultados: Los cambios histopatológicos causados por I/R disminuyeron con la administración de la vitamina A de manera dependiente de la dosis (p<0,05). La administración de la vitamina A disminuyó los niveles de MDA, aumentó las actividades de SOD y CAT (p<0,05). La dosis más eficaz entre los grupos del tratamiento fue de 9000 UI/kg. No hubo una diferencia significativa entre el grupo control y todos los demás grupos con respecto a las concentraciones de BUN y Cr. Conclusiones: Consiguientemente, la administración de la vitamina A, después de I/R renal, redujo el daño histológico y mejoró el estado antioxidante. Estos resultados mostraron que la vitamina A puede ser un agente promisorio en el tratamiento de la lesión renal aguda (LRA) inducida por I/R.

Quality control mechanism of mitochondria by 3,4-dihydroxybenzaldehyde through OGT-PINK1 pathway / 中国中药杂志

Based on the O-GlcNAc transferase(OGT)-PTEN-induced putative kinase 1(PINK1) pathway, the mechanism of 3,4-dihydroxybenzaldehyde(DBD) on mitochondrial quality control was investigated. Middle cerebral artery occlusion/reperfusion(MCAO/R) rats were established. SD rats were randomized into sham operation group(sham), model group(MCAO/R), DBD-L group(5 mg·kg~(-1)), and DBD-H group(10 mg·kg~(-1)). After 7 days of administration(ig), MCAO/R was induced in rats except the sham group with the suture method. Twenty-four h after reperfusion, the neurological function and the percentage of cerebral infarct area were measured. Based on hematoxylin and eosin(HE) staining and Nissl staining, the pathological damage of cerebral neurons was examined. Then the ultrastructure of mitochondria was observed under the electron microscope, and the co-localization of light chain-3(LC3), sequestosome-1(SQSTM1/P62), and Beclin1 was further detected by immunofluorescence staining. It has been reported that the quality of mitochondria can be ensured by inducing mitochondrial autophagy through the OGT-PINK1 pathway. Therefore, Western blot was employed to detect the expression of OGT, mitophagy-related proteins PINK1 and E3 ubiquitin ligase(Parkin), and mitochondrial kinetic proteins dynamin-like protein 1(Drp1) and optic atrophy 1(Opa1). The results showed that MCAO/R group had neurological dysfunction, large cerebral infarct area(P<0.01), damaged morphological structure of neurons, decreased number of Nissl bodies, mitochondrial swelling, disappearance of mitochondrial cristae, decrease of cells with LC3 and Beclin1, rise of cells with P62(P<0.01), inhibited expression of OGT, PINK1, and Parkin, up-regulated expression of Drp1, and down-regulated expression of Opa1 compared with the sham group(P<0.01). However, DBD improved the behavioral deficits and mitochondrial health of MCAO/R rats, as manifested by the improved morphology and structure of neurons and mitochondria and the increased Nissl bodies. Moreover, DBD increased cells with LC3 and Beclin1 and decreased cells with P62(P<0.01). In addition, DBD promoted the expression of OGT, PINK1, Parkin, and Opa1 and inhibited the expression of Drp1, enhancing mitophagy(P<0.05, P<0.01). In conclusion, DBD can trigger PINK1/Parkin-mediated brain mitophagy through the OGT-PINK1 pathway, which plays a positive role in maintaining the health of the mitochondrial network. This may be a mitochondrial therapeutic mechanism to promote nerve cell survival and improve cerebral ischemia/reperfusion injury.

Effect of Tongdu Tiaoshen electroacupuncture pretreatment on PPARγ-mediated pyroptosis of cerebral cortex in rats with cerebral ischemia reperfusion injury / 中国针灸

OBJECTIVE@#To observe the effect of Tongdu Tiaoshen (promoting the circulation of the governor vessel and regulating the spirit) electroacupuncture (EA) pretreatment on pyroptosis mediated by peroxisome proliferators-activated receptor γ (PPARγ) of the cerebral cortex in rats with cerebral ischemia reperfusion injury (CIRI) and explore the potential mechanism of EA for the prevention and treatment of CIRI.@*METHODS@#A total of 110 clean-grade male SD rats were randomly divided into a sham-operation group, a model group, an EA group, an EA + inhibitor group and an agonist group, 22 rats in each group. In the EA group, before modeling, EA was applied to "Baihui" (GV 20), "Fengfu" (GV 16) and "Dazhui" (GV 14), with disperse-dense wave, 2 Hz/5 Hz in frequency, 1 to 2 mA in intensity, lasting 20 min; once a day, consecutively for 7 days. On the base of the intervention as the EA group, on the day 7, the intraperitoneal injection with the PPARγ inhibitor, GW9662 (10 mg/kg) was delivered in the EA + inhibitor group. In the agonist group, on the day 7, the PPARγ agonist, pioglitazone hydrochloride (10 mg/kg) was injected intraperitoneally. At the end of intervention, except the sham-operation group, the modified thread embolization method was adopted to establish the right CIRI model in the rats of the other groups. Using the score of the modified neurological severity score (mNSS), the neurological defect condition of rats was evaluated. TTC staining was adopted to detect the relative cerebral infarction volume of rat, TUNEL staining was used to detect apoptosis of cerebral cortical nerve cells and the transmission electron microscope was used to observe pyroptosis of cerebral cortical neural cells. The positive expression of PPARγ and nucleotide-binding to oligomerization domain-like receptor protein 3 (NLRP3) in the cerebral cortex was detected with the immunofluorescence staining. The protein expression of PPARγ, NLRP3, cysteinyl aspartate specific protease-1 (caspase-1), gasdermin D (GSDMD) and GSDMD-N terminal (GSDMD-N) in the cerebral cortex was detected with Western blot. Using the quantitative real-time fluorescence-PCR, the mRNA expression of PPARγ, NLRP3, caspase-1 and GSDMD of the cerebral cortex was detected. The contents of interleukin (IL)-1β and IL-18 in the cerebral cortex of rats were determined by ELISA.@*RESULTS@#Compared with the sham-operation group, the mNSS, the relative cerebral infarction volume and the TUNEL positive cells rate were increased (P<0.01), pyroptosis was severe, the protein and mRNA expression levels of PPARγ, NLRP3, caspase-1 and GSDMD were elevated (P<0.01); and the protein expression of GSDMD-N and contents of IL-1β and IL-18 were increased (P<0.01) in the model group. When compared with the model group, the mNSS, the relative cerebral infarction volume and the TUNEL positive cells rate were decreased (P<0.01), pyroptosis was alleviated, the protein and mRNA expression levels of PPARγ were increased (P<0.01), the protein and mRNA expression levels of NLRP3, caspase-1 and GSDMD were decreased (P<0.01), the protein expression of GSDMD-N was reduced (P<0.01); and the contents of IL-1β and IL-18 were lower (P<0.01) in the EA group and the agonist group; while, in the EA + inhibitor group, the protein expression of PPARγ was increased (P<0.01), the protein and mRNA expression levels of NLRP3 and GSDMD were decreased (P<0.01, P<0.05), the mRNA expression of caspase-1 was reduced (P<0.01); and the contents of IL-1β and IL-18 were lower (P<0.01). When compared with the EA + inhibitor group, the mNSS, the relative cerebral infarction volume and the TUNEL positive cells rate were decreased (P<0.05, P<0.01), pyroptosis was alleviated, the protein and mRNA expression levels of PPARγ were increased (P<0.01), the protein and mRNA expression levels of NLRP3, caspase-1 and GSDMD were decreased (P<0.01), the protein expression of GSDMD-N was reduced (P<0.01); and the contents of IL-1β and IL-18 were declined (P<0.01) in the EA group. Compared with the agonist group, in the EA group, the relative cerebral infarction volume and the TUNEL positive cells rate were increased (P<0.05, P<0.01), the mRNA expression of PPARγ was decreased (P<0.01) and the protein expression of GSDMD-N was elevated (P<0.05); and the contents of IL-1β and IL-18 were higher (P<0.01).@*CONCLUSION@#Tongdu Tiaoshen EA pretreatment can attenuate the neurological impairment in the rats with CIRI, and the underlying mechanism is related to the up-regulation of PPARγ inducing the inhibition of NLRP3 in the cerebral cortex of rats so that pyroptosis is affected.

Effects of electroacupuncture pretreatment on GABAA receptor of fastigial nucleus and sympathetic nerve activity in rats with myocardial ischemia reperfusion injury / 中国针灸

OBJECTIVE@#To observe the effects of electroacupuncture (EA) pretreatment on cardiac function, sympathetic nerve activity, indexes of myocardial injury and GABAA receptor in fastigial nucleus in rats with myocardial ischemia reperfusion injury (MIRI), and to explore the neuroregulatory mechanism of EA pretreatment in improving MIRI.@*METHODS@#A total of 60 male SD rats were randomly divided into a sham operation group, a model group, an EA group, an agonist group and an agonist+EA group, 12 rats in each group. The MIRI model was established by ligation of the left anterior descending coronary artery. EA was applied at bilateral "Shenmen" (HT 7) and "Tongli" (HT 5) in the EA group and the agonist+EA group, with continuous wave, in frequency of 2 Hz and intensity of 1 mA, 30 min each time, once a day for 7 consecutive days. After intervention, the MIRI model was established. In the agonist group, the muscone (agonist of GABAA receptor, 1 g/L) was injected in fastigial nucleus for 7 consecutive days before modeling, 150 μL each time, once a day. In the agonist+EA group, the muscone was injected in fastigial nucleus 30 min before EA intervention. The data of electrocardiogram was collected by PowerLab standard Ⅱ lead, and ST segment displacement and heart rate variability (HRV) were analyzed; the serum levels of norepinephrine (NE), creatine kinase isoenzyme MB (CK-MB) and cardiac troponin I (cTnI) were detected by ELISA; the myocardial infarction area was measured by TTC staining; the morphology of myocardial tissue was observed by HE staining; the positive expression and mRNA expression of GABAA receptor in fastigial nucleus were detected by immunohistochemistry and real-time PCR.@*RESULTS@#Compared with the sham operation group, in the model group, ST segment displacement and ratio of low frequency to high frequency (LF/HF) of HRV were increased (P<0.01), HRV frequency domain analysis showed enhanced sympathetic nerve excitability, the serum levels of NE, CK-MB and cTnI were increased (P<0.01), the percentage of myocardial infarction area was increased (P<0.01), myocardial fiber was broken and interstitial edema was serious, the positive expression and mRNA expression of GABAA receptor in fastigial nucleus were increased (P<0.01). Compared with the model group, in the EA group, ST segment displacement and LF/HF ratio were decreased (P<0.01), HRV frequency domain analysis showed reduced sympathetic nerve excitability, the serum levels of NE, CK-MB and cTnI were decreased (P<0.01), the percentage of myocardial infarction area was decreased (P<0.01), myocardial fiber breakage and interstitial edema were lightened, the positive expression and mRNA expression of GABAA receptor in fastigial nucleus were decreased (P<0.01). Compared with the EA group, in the agonist group and the agonist+EA group, ST segment displacement and LF/HF ratio were increased (P<0.01), HRV frequency domain analysis showed enhanced sympathetic nerve excitability, the serum levels of NE, CK-MB and cTnI were increased (P<0.01), the percentage of myocardial infarction area was increased (P<0.01), myocardial fiber breakage and interstitial edema were aggravated, the positive expression and mRNA expression of GABAA receptor in fastigial nucleus were increased (P<0.01).@*CONCLUSION@#EA pretreatment can improve the myocardial injury in MIRI rats, and its mechanism may be related to the inhibition of GABAA receptor expression in fastigial nucleus, thereby down-regulating the excitability of sympathetic nerve.