Excitatory Synaptic Transmission in Ischemic Stroke: A New Outlet for Classical Neuroprotective Strategies.

Stroke is one of the leading causes of death and disability in the world, of which ischemia accounts for the majority. There is growing evidence of changes in synaptic connections and neural network functions in the brain of stroke patients. Currently, the studies on these neurobiological alterations mainly focus on the principle of glutamate excitotoxicity, and the corresponding neuroprotective strategies are limited to blocking the overactivation of ionic glutamate receptors. Nevertheless, it is disappointing that these treatments often fail because of the unspecificity and serious side effects of the tested drugs in clinical trials. Thus, in the prevention and treatment of stroke, finding and developing new targets of neuroprotective intervention is still the focus and goal of research in this field. In this review, we focus on the whole processes of glutamatergic synaptic transmission and highlight the pathological changes underlying each link to help develop potential therapeutic strategies for ischemic brain damage. These strategies include: (1) controlling the synaptic or extra-synaptic release of glutamate, (2) selectively blocking the action of the glutamate receptor NMDAR subunit, (3) increasing glutamate metabolism, and reuptake in the brain and blood, and (4) regulating the glutamate system by GABA receptors and the microbiota-gut-brain axis. Based on these latest findings, it is expected to promote a substantial understanding of the complex glutamate signal transduction mechanism, thereby providing excellent neuroprotection research direction for human ischemic stroke (IS).

The Cardiotoxicity Induced by Arsenic Trioxide is Alleviated by Salvianolic Acid A via Maintaining Calcium Homeostasis and Inhibiting Endoplasmic Reticulum Stress.

Arsenic trioxide (ATO) has been verified as a breakthrough with respect to the management of acute promyelocytic leukemia (APL) in recent decades but associated with some serious adverse phenomena, particularly cardiac functional abnormalities. Salvianolic acid A (Sal A) is a major effective component in treating ATO-induced cardiotoxicity. Therefore, the objective of our study was to assess whether Sal A had protective effects by the regulation of calcium homeostasis and endoplasmic reticulum (ER) stress. For the in vivo study, BALB/c mice were treated with ATO and/or Sal A via daily tail vein injections for two weeks. For the in vitro study, we detected the effects of ATO and/or Sal A in real time using adult rat ventricular myocytes (ARVMs) and an IonOptix MyoCam system. Our results showed that Sal A pretreatment alleviated cardiac dysfunction and Ca2+ overload induced by ATO in vivo and vitro. Moreover, Sal A increased sarcoplasmic reticulum (SR) Ca2+-ATPase (SERCA) activity and expression, alleviated [Ca2+]ER depletion, and decreased ER stress-related protein expression. Sal A protects the heart from ATO-induced injury and its administration correlates with the modulation of SERCA, the recovery of Ca2+ homeostasis, and the down-regulation of ER stress-mediated apoptosis.

Analysis of common and characteristic actions of Panax ginseng and Panax notoginseng in wound healing based on network pharmacology and meta-analysis.

In recent years, an increasing number of reports have explored the wound healing mechanism of these two traditional Chinese herbal medicines- Panax ginseng and Panax notoginseng, but there is no systematic research on the related core functions and different mechanisms in the treatment of wound healing up to now. Based on network pharmacology and meta-analysis, the present work aimed to comprehensively review the commonality and diversity of P. ginseng and P. notoginseng in wound healing. In this study, a wound healing-related "ingredients-targets" network of two herbs was constructed. Thereafter, meta-analysis of the multiple target lists by Metascape showed that these two medicines significantly regulated blood vessel development, responses to cytokines and growth factors and oxygen levels, cell death, cell proliferation and differentiation, and cell adhesion. To better understand the discrepancy between these two herbs, it was found that common signaling pathways including Rap1, PI3K/AKT, MAPK, HIF-1 and Focal adhesion regulated the functions listed above. In parallel, the different pathways including renin-angiotensin system, RNA transport and circadian rhythm, autophagy, and the different metabolic pathways may also explained the discrepancies in the regulation of the above-mentioned functions, consistent with the Traditional Chinese Medicine theory about the effects of P. ginseng and P. notoginseng.

ß-Sitosterol blocks the LEF-1-mediated Wnt/ß-catenin pathway to inhibit proliferation of human colon cancer cells.

OBJECTIVES: This study aimed to investigate the LEF-1-mediated Wnt/ß-catenin pathway for its biological functions and prognostic value in colon cancer (CC). Furthermore, the potential molecular mechanism of ß-sitosterol in CC was investigated in vitro. METHODS: Clinical information and gene expression profiles from CC patients were obtained based on Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases. In addition, we applied R software "Limma" package for the differential analysis of LEF-1 between cancer and para-carcinoma tissue samples. Kaplan-Meier (KM) survival analysis was adopted for analyzing whether LEF-1 was of prognostic significance. Moreover, gene set enrichment analysis (GSEA) was adopted for pathway enrichment analysis and visualization. In addition, CCK8, plate cloning, scratch and high-content screening (HCS) imaging assays were performed to examine the therapeutic efficacy of ß-sitosterol in human CC HCT116 cells. siRNA technology was employed to knock down LEF1 expression in HCT116 cells. qRT-PCR and Western-blot (WB) analysis were carried out to analyze the HCT-116 mRNA and protein expression levels, respectively. RESULTS: LEF-1 was up-regulated within CC and acted as an oncogenic gene. LEF-1 up-regulation predicted the dismal prognostic outcome and activated the Wnt/ß-catenin pathway. ß-sitosterol effectively suppressed HCT116 cells proliferation and invasion. For the mechanism underlying ß-sitosterol, ß-sitosterol was found to significantly down-regulate LEF-1 gene and protein expression and disrupt Wnt/ß-catenin pathway transmission in HCT116 cells. After suppressing LEF-1 expression, its downstream targets including C-myc, Survivin and CCND1 were also down-regulated. CONCLUSION: According to our results, LEF-1 down-regulation can effectively block Wnt/ß-catenin pathway, inhibit CC cell growth and migration. Collectively, ß-sitosterol can be used to treat CC, which can provide anti-tumor activity by targeting LEF-1.

Scutellarin attenuates oxidative stress and neuroinflammation in cerebral ischemia/reperfusion injury through PI3K/Akt-mediated Nrf2 signaling pathways.

Cerebral ischemia/reperfusion injury (CIRI) seriously threatens human life and health. Scutellarin (Scu) exhibits neuroprotective effects, but little is known about its underlying mechanism. Therefore, we explored its protective effect on CIRI and the underlying mechanism. Our results demonstrated that Scu rescued HT22 cells from cytotoxicity induced by oxygen and glucose deprivation/reoxygenation (OGD/R). Scu also showed antioxidant activity by promoting nuclear factor erythroid 2-related factor 2 (Nrf2) nuclear translocation, upregulating heme oxygenase-1 (HO-1) expression, increasing superoxide dismutase (SOD) activity, and inhibiting reactive oxygen species (ROS) generation in vitro. Additionally, Scu reduced nuclear factor-kappa B (NF-κB) activity and the levels of pro-inflammatory factors. Interestingly, these effects were abolished by Nrf2 inhibition. Furthermore, Scu reduced infarct volume and blood-brain barrier (BBB) permeability, improved sensorimotor functions and depressive behaviors, and alleviated oxidative stress and neuroinflammation in rats subjected to middle cerebral artery occlusion/reperfusion (MCAO/R). Mechanistically, Scu-induced Nrf2 nuclear accumulation and inactivation of NF-κB were accompanied by an enhanced level of phosphorylated protein kinase B (p-AKT) both in vitro and in vivo. Pharmacologically inhibiting the phosphatidylinositol-3-kinase/protein kinase B (PI3K/AKT) pathway blocked Scu-induced Nrf2 nuclear translocation and inactivation of NF-κB, as well as its antioxidant and anti-inflammatory activities. In summary, these results suggest that Scu exhibits antioxidant, anti-inflammatory, and neuroprotective effects in CIRI through Nrf2 activation mediated by the PI3K/Akt pathway.

Protective Effects of Biscoclaurine Alkaloids on Leukopenia Induced by 60Co-γ Radiation.

OBJECTIVE: Leukopenia, a common complication of tumor chemoradiotherapy, contributes serious damage to the hematopoietic, gastrointestinal, and immune systems of the body and can cause delay, discontinuation, or even failure to tumor treatment, thereby greatly threatening human health. The present study aims to investigate the protective effects of biscoclaurine alkaloids (BA) on leukopenia. METHODS: This study was conducted on 60 Kunming mice, which were randomly divided into six groups containing 10 animals each. A hematology analyzer was used to count white blood cells (WBC) in the peripheral blood cell. Mice serum was collected, and the granulocyte-macrophage colony-stimulating factor, vascular cell adhesion molecule 1 (VCAM-1), and interferon-γ (IFN-γ) were detected by enzyme-linked immunosorbent assays. Pathological changes were detected through hematoxylin and eosin staining in the liver and spleen of mice. The spleen and liver ultrastructures were observed via electron microscopy. RESULTS: Results showed that BA ameliorated WBC, PLT reduction in the peripheral blood and significantly increased the levels of IFN-γ and VCAM-1 in mice serum. BA reduced ionizing radiation-induced injuries to spleen, mitigated the reduction of superoxide dismutase (SOD), and significantly decreased the malonaldehyde (MDA) and xanthine oxidase (XOD) levels in the liver. CONCLUSION: BA enhanced the immune and hematopoietic functions and ameliorated the oxidative stress induced by 60Co-γ radiation, revealing its therapeutic potential both as a radioprotector and as a radiation mitigator for leukopenia induced by 60Co-γ radiation.

Calenduloside E Ameliorates Myocardial Ischemia-Reperfusion Injury through Regulation of AMPK and Mitochondrial OPA1.

Calenduloside E (CE) is a natural triterpenoid saponin isolated from Aralia elata (Miq.) Seem., a well-known traditional Chinese medicine. Our previous studies have shown that CE exerts cardiovascular protective effects both in vivo and in vitro. However, its role in myocardial ischemia/reperfusion injury (MIRI) and the mechanism involved are currently unknown. Mitochondrial dynamics play a key role in MIRI. This study investigated the effects of CE on mitochondrial dynamics and the signaling pathways involved in myocardial ischemia/reperfusion (MI/R). The MI/R rat model and the hypoxia/reoxygenation (H/R) cardiomyocyte model were established in this study. CE exerted significant cardioprotective effects in vivo and in vitro by improving cardiac function, decreasing myocardial infarct size, increasing cardiomyocyte viability, and inhibiting cardiomyocyte apoptosis associated with MI/R. Mechanistically, CE restored mitochondrial homeostasis against MI/R injury through improved mitochondrial ultrastructure, enhanced ATP content and mitochondrial membrane potential, and reduced mitochondrial permeability transition pore (MPTP) opening, while promoting mitochondrial fusion and preventing mitochondrial fission. However, genetic silencing of OPA1 by siRNA abolished the beneficial effects of CE on cardiomyocyte survival and mitochondrial dynamics. Moreover, we demonstrated that CE activated AMP-activated protein kinase (AMPK) and treatment with the AMPK inhibitor, compound C, abolished the protective effects of CE on OPA1 expression and mitochondrial function. Overall, this study demonstrates that CE is effective in mitigating MIRI by modulating AMPK activation-mediated OPA1-related mitochondrial fusion.

Araloside C protects H9c2 cardiomyoblasts against oxidative stress via the modulation of mitochondrial function.

Araloside C (AsC) has potential cardioprotective properties. However, the underlying mechanism of AsC-mediated cardioprotection, especially the role of mitochondrial function, remains largely unknown. Here, we used H9c2 cardiomyocytes to study the cardioprotective mechanisms of AsC through H2O2-induced oxidative stress. Cell viability, lactate dehydrogenase release, mitochondrial functions and bioenergetics were evaluated. Western blot analysis was used to measure the protein expression levels of apoptosis and the phosphorylation of AMP-activated protein kinase (AMPK). Results revealed that AsC increased cell viability, improved mitochondrial membrane potential disruption, decreased mitochondrial reactive oxygen species level, elevated cellular ATP levels and alleviated impaired mitochondrial respiration in H2O2-induced H9c2 cardiomyoblasts injury. Furthermore, AsC modulated apoptosis-associated protein expression and AMPK pathway in H9c2 cells under oxidative stress. In conclusion, AsC potentially protects H9c2 cardiomyoblasts against oxidative stress by regulating mitochondrial function and AMPK activation. AsC may be an effective therapeutic agent for the prevention of oxidative stress in cardiac injury.

An integrated characterization of contractile, electrophysiological, and structural cardiotoxicity of Sophora tonkinensis Gapnep. in human pluripotent stem cell-derived cardiomyocytes.

BACKGROUND: Cardiotoxicity remains an important concern in drug discovery and clinical medication. Meanwhile, Sophora tonkinensis Gapnep. (S. tonkinensis) held great value in the clinical application of traditional Chinese medicine, but cardiotoxic effects were reported, with matrine, oxymatrine, cytisine, and sophocarpine being the primary toxic components. METHODS: In this study, impedance and extracellular field potential (EFP) of human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) were recorded using the cardio non-labeled cell function analysis and culture system (Cardio-NLCS). The effects of matrine, oxymatrine, cytisine, and sophocarpine (2, 10, 50 µM) on cell viability; level of lactate dehydrogenase (LDH), creatine kinase MB isoenzyme (CK-MB), and cardiac troponin I (CTn-I); antioxidant activities; production of reactive oxygen species (ROS) and malondialdehyde (MDA); and disruption of intracellular calcium homeostasis were also added into the integrated assessment. RESULTS: The results showed that matrine and sophocarpine dose-dependently affected both impedance and EFP, while oxymatrine and cytisine altered impedance significantly. Our study also indicated that cardiotoxicity of matrine, oxymatrine, cytisine, and sophocarpine was related to the disruption of calcium homeostasis and oxidative stress. Four alkaloids of S. tonkinensis showed significant cardiotoxicity with dose dependence and structural cardiotoxicity synchronized with functional changes of cardiomyocytes. CONCLUSIONS: This finding may provide guidance for clinical meditation management. Furthermore, this study introduced an efficient and reliable approach, which offers alternative options for evaluating the cardiotoxicity of the listed drugs and novel drug candidates.

Shuxuening injection protects against myocardial ischemia-reperfusion injury through reducing oxidative stress, inflammation and thrombosis.

BACKGROUND: Shuxuening injection (SXNI) has a good effect on cardiovascular and cerebrovascular diseases. Here, our study aims to investigate whether SXNI have the protective effect on myocardial ischemia-reperfusion injury (MIRI) and elucidate the mechanism of SXNI's cardiac protection. METHODS: In this experiment, the coronary arteries of Sprague-Dawley (SD) rats were ligated for the induction of a MIRI model. TTC staining and haematoxylin-eosin (HE), as well as troponin I (TnI), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), creatine kinase (CK) and CK-MB levels, were used to detect the protective effect of SXNI. In rat cardiac tissue, superoxide dismutase, catalase, glutathione and malondialdehyde (MDA) activities and glucose-regulated protein 78 (GRP78), calreticulin (CRT), CCAAT/enhancer binding protein homologous protein (CHOP) and caspase-12 expression levels were detected. In rat serum, the levels of inflammatory factors, including high-sensitivity C-reactive protein, monocyte chemoattractant protein-1, tumour necrosis factor-α, interleukin-6 (IL-6) and IL-1ß, were measured by Elisa. In the rat arterial tissue, Toll-like receptor 4 (TLR4)/nuclear factor kappa B (NF-κB) expression was measured by western blot. In the rat plasma, ELISA was used to assay the levels of coagulation and plasmin system indicators, including platelet activating factor, endothelin, tissue factor (TF), plasminogen inhibitor, thromboxane B2, plasma fibrinogen. RESULTS: The results showed that SXNI can reduce the infarct size of myocardial tissue, decrease the myocardial enzyme and TnI levels and decrease the degree of myocardial damage compared with the model group. Additionally, SXNI can increase the activity of antioxidant enzymes, reduce the MDA level and decrease the GRP78, CRT, CHOP and caspase-12 expression levels. SXNI also decreased the levels of inflammatory cytokines in rat serum, lowered the level of procoagulant molecules in plasma and reduced the TLR4/NF-κB expression. CONCLUSIONS: SXNI has protective effect on MIRI mainly by inhibiting oxidative stress and endoplasmic reticulum stress (ERS), thereby regulating TLR4/NF-κB pathway to reduce inflammation, and lowing procoagulant-related factors levels to reduce the risk of thrombosis.