DUSP14 rescues cerebral ischemia/reperfusion (IR) injury by reducing inflammation and apoptosis via the activation of Nrf-2

NRF2 inhibitors: Recent progress, future design and therapeutic potential

Nuclear factor erythroid 2-related factor 2 (NRF2) is a crucial transcription factor involved in oxidative stress response, which controls the expression of various cytoprotective genes. Recent research has indicated that constitutively activated NRF2 can enhance patients' resistance to chemotherapy drugs, resulting in unfavorable prognosis. Therefore, the development of NRF2 inhibitors has emerged as a promising approach for overcoming drug resistance in cancer treatment. However, there are limited reports and reviews focusing on NRF2 inhibitors. This review aims to provide a comprehensive analysis of the structure and regulation of the NRF2 signaling pathway, followed by a comprehensive review of reported NRF2 inhibitors. Moreover, the current design strategies and future prospects of NRF2 inhibitors will be discussed, aiming to establish a foundation for the development of more effective NRF2 inhibitors.

Inhibiting TRIM8 alleviates adipocyte inflammation and insulin resistance by regulating the DUSP14/MAPKs pathway

Obesity is a low-grade chronic inflammation induced by the pathological expansion of adipocytes which allows the development of obesity-associated metabolic diseases like type 2 diabetes mellitus (T2D) and non-alcoholic fatty liver disease (NAFLD). However, mechanisms regulating adipocyte inflammation remain poorly understood. Here, we observed that TRIM8 was upregulated in adipocyte inflammation and insulin resistance while DUSP14 was downregulated. TRIM8 deficiency and DUSP14 over-expression decreased the level of inflammatory cytokines, increased glucose uptake content, and improved insulin signalling transduction compared to LPS treatment alone. Conversely, silencing DUSP14 increased the expression of inflammatory cytokines. It decreased the glucose uptake content and the phosphorylation level of proteins involved in insulin signalling, further impairing insulin signalling and aggravating insulin resistance. Furthermore, The decreased level of inflammatory cytokines, increased glucose uptake, and improved insulin signalling transduction caused by TRIM8 deficiency were reversed by down-regulated DUSP14. Collectively, our findings revealed that TRIM8 can regulate adipocyte inflammation and insulin resistance by regulating the MAPKs pathway which is dependent on DUSP14.

Biliverdin modulates the Nrf2/A20/eEF1A2 axis to alleviate cerebral ischemia-reperfusion injury by inhibiting pyroptosis

This study aimed to examine whether Biliverdin, which is a common metabolite of haem, can alleviate cerebral ischemia reperfusion injury (CIRI) by inhibiting pyroptosis. Here, CIRI was induced by middle cerebral artery occlusion-reperfusion (MCAO/R) in C57BL/6 J mice and modelled by oxygen and glucose deprivation/reoxygenation (OGD/R) in HT22 cells, it was treated with or without Biliverdin. The spatiotemporal expression of GSDMD-N and infarction volumes were assessed by immunofluorescence staining and triphenyltetrazolium chloride (TTC), respectively. The NLRP3/Caspase-1/GSDMD pathway, which is central to the pyroptosis process, as well as the expression of Nrf2, A20, and eEF1A2 were determined by Western-blots. Nrf2, A20, and eEF1A2 interactions were verified using dual-luciferase reporter assays, chromatin immunoprecipitation, or co-immunoprecipitation. Additionally, the role of Nrf2/A20/eEF1A2 axis in modulating the neuroprotective properties of Biliverdin was investigated using A20 or eEF1A2 gene interference (overexpression and/or silencing). 40 mg/kg of Biliverdin could significantly alleviate CIRI both in vivo and in vitro, promoted the activation of Nrf2, elevated A20 expression, but decreased eEF1A2 expression. Nrf2 can bind to the promoter of A20, thereby transcriptionally regulating the expression of A20. A20 can furthermore interacted with eEF1A2 through its ZnF4 domain to ubiquitinate and degrade it, leading to the downregulation of eEF1A2. Our studies have also demonstrated that either the knock-down of A20 or over-expression of eEF1A2 blunted the protective effect of Biliverdin. Rescue experiments further confirmed that Biliverdin could regulate the NF-κB pathway via the Nrf2/A20/eEF1A2 axis. In summary, our study demonstrates that Biliverdin ameliorates CIRI by inhibiting the NF-κB pathway via the Nrf2/A20/eEF1A2 axis. Our findings can help identify novel therapeutic targets for the treatment of CIRI.

After Ischemic Stroke, Minocycline Promotes a Protective Response in Neurons via the RNA-Binding Protein HuR, with a Positive Impact on Motor Performance

Ischemic stroke is the most common cause of adult disability and one of the leading causes of death worldwide, with a serious socio-economic impact. In the present work, we used a new thromboembolic model, recently developed in our lab, to induce focal cerebral ischemic (FCI) stroke in rats without reperfusion. We analyzed selected proteins implicated in the inflammatory response (such as the RNA-binding protein HuR, TNFα, and HSP70) via immunohistochemistry and western blotting techniques. The main goal of the study was to evaluate the beneficial effects of a single administration of minocycline at a low dose (1 mg/kg intravenously administered 10 min after FCI) on the neurons localized in the penumbra area after an ischemic stroke. Furthermore, given the importance of understanding the crosstalk between molecular parameters and motor functions following FCI, motor tests were also performed, such as the Horizontal Runway Elevated test, CatWalk™ XT, and Grip Strength test. Our results indicate that a single administration of a low dose of minocycline increased the viability of neurons and reduced the neurodegeneration caused by ischemia, resulting in a significant reduction in the infarct volume. At the molecular level, minocycline resulted in a reduction in TNFα content coupled with an increase in the levels of both HSP70 and HuR proteins in the penumbra area. Considering that both HSP70 and TNF-α transcripts are targeted by HuR, the obtained results suggest that, following FCI, this RNA-binding protein promotes a protective response by shifting its binding towards HSP70 instead of TNF-α. Most importantly, motor tests showed that reduced inflammation in the brain damaged area after minocycline treatment directly translated into a better motor performance, which is a fundamental outcome when searching for new therapeutic options for clinical practice.

Sevoflurane Post-treatment Mitigates Oxygen-glucose Deprivationinduced Pyroptosis of Hippocampal Neurons by Regulating the Mafb/DUSP14 Axis

BACKGROUND

Ischemic brain injury often results in irreversible pyroptosis of neurons. Sevoflurane (Sevo) post-treatment exerts an alleviative role in neuroinflammation.

OBJECTIVES

This work evaluated the mechanism of Sevo post-treatment in oxygen-glucose deprivation (OGD)-induced pyroptosis of rat hippocampal neurons.

METHODS

Rat hippocampal neuron cell line H19-7 cells were treated with OGD, followed by posttreatment of 2% Sevo. The expression patterns of Mafb ZIP Transcription Factor B (Mafb) and dual- specificity phosphatase 14 (DUSP14) were determined via quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting methods. H19-7 cell viability and the release of lactate dehydrogenase (LDH) were examined via the cell counting kit-8 and LDH assay kits. Levels of pyroptosis-related proteins and cytokines NOD-like receptor family, pyrin domain containing 3 (NLRP3), N-term cleaved Gasdermin-D (GSDMD-N), cleaved-caspase-1, interleukin (IL)-1β, and IL-18 were also examined. The binding relation between Mafb and the DUSP14 promoter was detected. Besides, the roles of Mafb/DUSP14 in OGD-induced pyroptosis of rat hippocampal neurons were investigated through functional rescue experiments.

RESULTS

Mafb and DUSP14 expression levels were decreased in OGD-induced hippocampal neurons. Sevo post-treatment up-regulated Mafb and DUSP14, facilitated H19-7 cell viability, inhibited LDH release, and reduced levels of NLRP3, GSDMD-N, cleaved-caspase-1, IL-1β, and IL-18. Mafb increased DUSP14 expression via binding to the DUSP14 promoter. Repressing Mafb or DUSP14 exacerbated pyroptosis of hippocampal neurons.

CONCLUSION

Sevo post-treatment increased Mafb and DUSP14 expressions, which repressed OGDinduced pyroptosis of hippocampal neurons.

Inflammatory Responses After Ischemic Stroke

Ischemic stroke generates an immune response that contributes to neuronal loss as well as tissue repair. This is a complex process involving a range of cell types and effector molecules and impacts tissues outside of the CNS. Recent reviews address specific aspects of this response, but several years have passed and important advances have been made since a high-level review has summarized the overall state of the field. The present review examines the initiation of the inflammatory response after ischemic stroke, the complex impacts of leukocytes on patient outcome, and the potential of basic science discoveries to impact the development of therapeutics. The information summarized here is derived from broad PubMed searches and aims to reflect recent research advances in an unbiased manner. We highlight valuable recent discoveries and identify gaps in knowledge that have the potential to advance our understanding of this disease and therapies to improve patient outcomes.

Microwave assisted extraction, characterization of a polysaccharide from Salvia miltiorrhiza Bunge and its antioxidant effects via ferroptosis-mediated activation of the Nrf2/HO-1 pathway

A microwave-assisted extraction procedure for the crude Salvia miltiorrhiza polysaccharides (SMPs) obtained from Salvia miltiorrhiza Bunge was optimized. Four independent variables were studied: microwave power, extraction time, solvent-to-solid ratio, and concentration of ethanol, with optimal settings of 1200 W, 12 min, 38, and 86 %, respectively. The SMPs were successively purified by DEAE Sepharose Fast Flow and Sephadex G-100 chromatography to produce a novel polysaccharide termed SMP1. The SMP1 was composed of glucose, galactose, and fructose in a molar ratio of 1:1.67:1.12 with an average molecular weight of 6087 Da. Pharmacological studies showed that SMP1 protected from OGD/R-induced ferroptosis and lipid peroxidation by activating Nrf2/HO-1 pathway in PC12 cells. Our research systematically indicated that polysaccharide could inhibit ferroptosis to alleviate oxidative stress injury, which laid the foundation for the future clinical application of Salvia miltiorrhiza polysaccharide.

Gomisin J attenuates cerebral ischemia/reperfusion injury by inducing anti-apoptotic, anti-inflammatory, and antioxidant effects in rats

Ischemic stroke is one of the leading causes of morbidity and mortality in humans. Cerebral ischemia-reperfusion (CIR) injury serves as a leading cause of stroke. Schisandra chinensis is a well-known Chinese traditional medicine. In this study, we explored the role of Gomisin J (GJ), a compound of S. chinensis, in CIR using a middle cerebral artery occlusion/reperfusion rat model and the possible mechanisms. We identified that GJ reduced neurological scores, cerebral infarction, and water content in the I/R rat brain. Importantly, GJ rescued I/R treatment-reduced neuron survival in the hippocampus, inhibited apoptosis of ischemic tissues in I/R rats, increased B-cell lymphoma-extra-large (Bcl-XL) expression, and reduced the levels of cleaved caspase-3, Bax, cyclooxygenase-2, nuclear factor kappa-B, and nitric oxide in I/R rat brain tissues. Furthermore, GJ treatment enhanced nuclear factor E2 related factor 2 (Nrf2) translocation, heme oxygenase-1 (HO-1) expression, superoxide dismutase and glutathione peroxidase activities, and glutathione level. Overall, GJ treatment GJ attenuates CIR injury by inducing anti-apoptotic, antioxidant, and anti-inflammatory effects in vivo.

HIF‑1α in cerebral ischemia (Review)

Cerebral ischemic injury may lead to a series of serious brain diseases, death or different degrees of disability. Hypoxia-inducible factor-1α (HIF-1α) is an oxygen-sensitive transcription factor, which mediates the adaptive metabolic response to hypoxia and serves a key role in cerebral ischemia. HIF-1α is the main molecule that responds to hypoxia. HIF-1α serves an important role in the development of cerebral ischemia by participating in numerous processes, including metabolism, proliferation and angiogenesis. The present review focuses on the endogenous protective mechanism of cerebral ischemia and elaborates on the role of HIF-1α in cerebral ischemia. In addition, it focuses on cerebral ischemia interventions that act on the HIF-1α target, including biological factors, non-coding RNA, hypoxic-ischemic preconditioning and drugs, and expands upon the measures to strengthen the endogenous compensatory response to support HIF-1α as a therapeutic target, thus providing novel suggestions for the treatment of cerebral ischemia.

Enhancement of DUSP14 (dual specificity phosphatase 14) limits osteoarthritis progression by alleviating chondrocyte injury, inflammation and metabolic homeostasis

Osteoarthritis (OA) is a proverbial inflammatory degenerative joint disease associated with the acceleration of the aging process and is characterized by chondrocyte injury and articular cartilage degradation. Dual-specificity phosphatase 14 (Dusp14), a common member of the DUSP family, has been implicated in multiple inflammatory diseases and bone loss. Nevertheless, the function of DUSP14 in OA remains unclear. In the present study, down-regulation of DUSP14 was corroborated in anterior cruciate ligament transection (ACLT)-induced OA rats and interleukin-1β (IL-1β)-stimulated chondrocytes. Additionally, the gain of DUSP14 reversed IL-1β-induced inhibition of chondrocyte viability but attenuated cell apoptosis. Concomitantly, DUSP14 overexpression muted IL-1β-induced release of pro-inflammatory mediators NO and prostaglandin E2 (PGE2), as well as pro-inflammatory cytokine levels (IL-6 and TNF-α). Furthermore, up-regulation of DUSP14 overturned the effects of IL-1β on the inhibition of collagen II and aggrecan expression, and enhancement of A Disintegrin and Metalloproteinase with Thrombospondin Motifs 5 (ADAMTS5) and matrix metalloproteinases (MMPs; MMP3 and MMP-13). Mechanistically, DUSP14 elevation increased the p-Adenosine 5ʹ-monophosphate-activated protein activated protein kinase(AMPK), inhibitor of NF-κB (IκB) expression and decreased p-p65 NF-κB expression, indicating that DUSP14 might restore the AMPK-IκB pathway to restrain NF-κB signaling under IL-1β exposure. Notably, blockage of AMPK signaling muted the protective efficacy of DUSP14 elevation against IL-1β-induced inflammatory injury and metabolism disturbance in chondrocytes. Interestingly, histological evaluation substantiated that DUSP14 injection alleviated cartilage degradation in OA rats. Together, DUSP14 may ameliorate OA progression by affecting chondrocyte injury, inflammatory response and cartilage metabolism homeostasis, implying a promising therapeutic strategy against OA.

The Nrf2 Pathway in Ischemic Stroke: A Review

Ischemic stroke, characterized by the sudden loss of blood flow in specific area(s) of the brain, is the leading cause of permanent disability and is among the leading causes of death worldwide. The only approved pharmacological treatment for acute ischemic stroke (intravenous thrombolysis with recombinant tissue plasminogen activator) has significant clinical limitations and does not consider the complex set of events taking place after the onset of ischemic stroke (ischemic cascade), which is characterized by significant pro-oxidative events. The transcription factor Nuclear factor erythroid 2-related factor 2 (Nrf2), which regulates the expression of a great number of antioxidant and/or defense proteins, has been pointed as a potential pharmacological target involved in the mitigation of deleterious oxidative events taking place at the ischemic cascade. This review summarizes studies concerning the protective role of Nrf2 in experimental models of ischemic stroke, emphasizing molecular events resulting from ischemic stroke that are, in parallel, modulated by Nrf2. Considering the acute nature of ischemic stroke, we discuss the challenges in using a putative pharmacological strategy (Nrf2 activator) that relies upon transcription, translation and metabolically active cells in treating ischemic stroke patients.

Association between GFAP-positive astrocytes with clinically important parameters including neurological deficits and/or infarct volume in stroke-induced animals

The effect of GFAP-positive astrocytes, as positive or negative factors on stroke complications such as infarct volume and neurological deficits is currently under debate. This review was aimed to evaluate and compare the frequency of studies that showed a positive or negative relationship between astrocyte activation with the improvement of neurological deficits and/or the decrease of infarct volume. In addition, we reviewed two possible causes of differences in results including timepoint of stroke and stroke severity. Time of GFAP assessment was considered as time point and type of stroke induction and duration of stroke as stroke severity. According to our review in the most relevant English-language studies in the PubMed, Web of Science, and Google Scholar databases from 2005 to 2020, the majority of studies (77 vs. 28) showed a negative coincidence or correlation between GFAP-positive cells with neurological improvement as well as between GFAP-positive cells with infarct volume reduction. In most reviewed studies, GFAP expression was reported as a marker related to or coinciding with worse neurological function, or greater infarct volume. However, there were also studies that showed helpful effects of GFAP-positive cells on neurological function or stroke lesion. Although there are some elucidations that the difference in these findings is due to the time point of stroke and stroke severity, our review did not confirm these interpretations.

Neuroprotective effect of minocycline against acute brain injury in clinical practice: A systematic review

Acute brain injury is a leading cause of morbidity and mortality worldwide. The term is inclusive of traumatic brain injury, cerebral ischemia, subarachnoid hemorrhage, and intracerebral hemorrhage. Current pharmacologic treatments have had minimal effect on improving neurological outcomes leading to a significant interest in the development neuroprotective agents. Minocycline is a second-generation tetracycline with high blood brain barrier penetrance due to its lipophilic properties. It functions across multiple molecular pathways involved in secondary-injury cascades following acute brain injury. Animal model studies suggest that minocycline might lead to improved neurologic outcomes, but few such trials exist in humans. Clinical investigations have been limited to small randomized trials in ischemic stroke patients which have not demonstrated a clear advantage in neurologic outcomes, but also have not been sufficiently powered to draw definitive conclusions. The potential neuroprotective effect of minocycline in the setting of traumatic brain injury, subarachnoid hemorrhage, and intracerebral hemorrhage have all been limited to pilot studies with phase II/III investigations pending. The authors aim to synthesize what is currently known about minocycline as a neuroprotective agent against acute brain injury in humans.

Anagliptin Protected against Hypoxia/Reperfusion-Induced Brain Vascular Endothelial Permeability by Increasing ZO-1

BACKGROUND AND PURPOSE

Cerebral ischemia-reperfusion injury is commonly induced during the treatment of ischemic stroke and is reported to be related to the blood-brain barrier destruction and brain vascular endothelial cell dysfunction. Anagliptin is a novel antidiabetic agent recently reported to protect neurons from oxidative stress. In the present study, we aim to investigate the protective property of anagliptin against oxygen-glucose deprivation and reperfusion (OGD/R)-induced injury on endothelial cells and clarify the potential underlying mechanism.

METHODS

OGD/R modeling was established on bEnd.3 brain endothelial cells. Cell viability was detected using the MTT assay, and the mitochondrial reactive oxygen species (ROS) level was measured using the mitoses red staining assay. The endothelial monolayer permeability was determined using an FITC-dextran permeation assay. The expression levels of NOX-4 and ZO-1 were evaluated using qRT-PCR and Western blot assays. The expressions of MLC-2, p-MLC-2, and myosin light chain kinase (MLCK) were determined using Western blot.

RESULTS

First, the decreased cell viability, upregulated NOX-4, and elevated mitochondrial ROS level in the endothelial cells induced by OGD/R were reversed by treatment with anagliptin. Second, the enlarged endothelial permeability and the decreased expression level of ZO-1 in the endothelial cells induced by OGD/R were alleviated by anagliptin. Third, the downregulation of ZO-1 and enlarged brain endothelial monolayer permeability induced by OGD/R were ameliorated by an MLCK inhibitor, ML-7. Lastly, the elevated expressions of MLCK and p-MLC-2 induced by OGD/R were suppressed by anagliptin.

CONCLUSION

Anagliptin protected against hypoxia/reperfusion-induced brain vascular endothelial permeability by increasing the expression ZO-1, mediated by inhibition of the MLCK/MLC-2 signaling pathway.

Eriocitrin attenuates ischemia reperfusion-induced oxidative stress and inflammation in rats with acute kidney injury by regulating the dual-specificity phosphatase 14 (DUSP14)-mediated Nrf2 and nuclear factor-κB (NF-κB) pathways

Background

Ischemia reperfusion (IR)-induced acute kidney injury (AKI) is accompanied by increased inflammatory response and oxidative stress. Eriocitrin is a flavonoid that is mainly derived from lemon or citrate juice. It exhibits various pharmacological effects and is known to have antioxidant and anti-steatotic benefits. However, research on the effect of eriocitrin against IR-induced oxidative stress and inflammation in AKI is limited.

Methods

In this study, an OGD/R of HK-2 cell in vitro and rat model of AKI in vivo were constructed. Then the cell or rats were treated with eriocitrin at different doses (60, 30, 10 mg/kg). The levels of apoptotic were detected by flow cytometry. Inflammatory and oxidative stress factors in supernatant in vitro and tissue in vivo. Meanwhile, Western blot was used to detect the change of dual-specificity phosphatase 14 (DUSP14), Nrf2 and nuclear factor-κB (NF-κB).

Results

Eriocitrin attenuated apoptosis of the human renal tubular epithelial cell line HK-2 mediated by oxygen glucose deprivation/reperfusion via the repression of inflammation and oxidative stress in a dose-dependent manner. Eriocitrin also enhanced the levels of dual-specificity phosphatase 14 (DUSP14) and Nrf2, and decreased NF-κB phosphorylation. Furthermore, the in vivo experiments indicated that eriocitrin dose-dependently alleviated IR-induced AKI and apoptosis in rats. By elevating DUSP14, eriocitrin promoted the expression of Nrf2 and inactivated NF-κB, thereby downregulating inflammation and oxidative stress. Moreover, inhibiting DUSP14 expression with protein tyrosine phosphatase (PTP) inhibitor IV reversed the kidney-protective effects of Eriocitrin.

Conclusions

Eriocitrin protected IR-induced AKI by attenuating oxidative stress and inflammation via elevating DUSP14, thereby providing a theoretical basis for the treatment of IR-induced AKI.

Protective effects of polysaccharides on cerebral ischemia: A mini-review of the mechanisms

Cerebral ischemia, a common cerebrovascular disease, is one of the great threats to human health. Nowadays, many drugs used in the treatment of cerebral ischemia such as clot busting drugs, antiplatelet drugs, and neuroprotective drugs have limits. It is urgent finding new effective treatments for the patients. Researches have confirmed that many kinds of polysaccharides from natural resources possess therapeutic effects on cerebral ischemia, but are still lack of a comprehensively understanding. In this paper, based on the pathophysiology of cerebral ischemic injury, we summarize the latest discoveries and advancements of 29 kinds of polysaccharides, focusing on their ameliorating effects on cerebral ischemia and the underlying mechanisms. Several mechanisms are involved, mainly including antioxidant activities, anti-inflammatory activities, regulating neuron apoptosis, as well as resisting nitrosative stress injury. Besides, polysaccharides show protective effects through certain signaling pathways including PI3K/Akt, MAPK, and NF-κB, PARP-1/AIF, JNK3/c-Jun/Fas-L, and Nrf2/HO-1 signaling pathways. The main goal of this mini-review is to emphasize the important roles of polysaccharides in attenuating cerebral ischemic injury through the elucidation of mechanisms.

S100a8 silencing attenuates inflammation, oxidative stress and apoptosis in BV2 cells induced by oxygen‑glucose deprivation and reoxygenation by upregulating GAB1 expression

S100a8 serves an important role in cell differentiation and is abnormally expressed in common tumors, but there are few studies on the association between S100a8 and brain I/R injury. The present study aimed to investigate the role of S100a8 in oxygen-glucose deprivation and reoxygenation (OGD/R)-induced BV2 microglia cell injury, and to elucidate the potential underlying molecular mechanisms. BV2 cells were exposed to OGD/R to mimic ischemia/reperfusion (I/R) injury in vitro. S100a8 expression was detected via reverse transcription-quantitative PCR and western blot analyses. Following transfection with short hairpin RNAs targeting S100a8, the levels of inflammatory cytokines and oxidative stress-related factors were determined using commercial kits. Apoptosis was assessed using flow cytometric analysis and the expression levels of apoptosis-related proteins were determined using western blot analysis. Subsequently, the mRNA and protein levels of Grb2-associated binder 1 (GAB1) were assessed following S100a8 silencing. Immunoprecipitation (IP) was performed to verify the association between S100a8 and GAB1. The levels of inflammation, oxidative stress and apoptosis were assessed following GAB1 silencing, along with S100a8 silencing in BV2 cells subjected to OGD/R. The results indicated that exposure to OGD/R markedly upregulated S100a8 expression in BV2 cells. S100a8 silencing inhibited inflammation, oxidative stress and apoptosis, accompanied by changes in the expression of related proteins. The IP assay revealed a strong interaction between GAB1 and S100a8. In addition, GAB1 silencing reversed the inhibitory effects of S100a8 silencing on inflammation, oxidative stress and apoptosis in OGD/R-stimulated BV2 cells. Taken together, the results of the present study demonstrated that S100a8 silencing alleviated inflammation, oxidative stress and the apoptosis of BV2 cells induced by OGD/R, partly by upregulating the expression of GAB1. Thus, these findings may potentially provide a novel direction to develop therapeutic strategies for cerebral I/R injury.

Post-translational Modification of OTULIN Regulates Ubiquitin Dynamics and Cell Death

Linear ubiquitination has emerged as an important post-translational modification that regulates NF-κB activation, inflammation, and cell death in both immune and non-immune compartments, including the skin. The deubiquitinase OTULIN specifically disassembles linear ubiquitin chains generated by the linear ubiquitin assembly complex (LUBAC) and is necessary to prevent embryonic lethality and autoinflammatory disease. Here, we dissect the direct role of OTULIN in cell death and find that OTULIN limits apoptosis and necroptosis in keratinocytes. During apoptosis, OTULIN is cleaved by capase-3 at Asp-31 into a C-terminal fragment that restricts caspase activation and cell death. During necroptosis, OTULIN is hyper-phosphorylated at Tyr-56, which modulates RIPK1 ubiquitin dynamics and promotes cell death. OTULIN Tyr-56 phosphorylation is counteracted by the activity of dual-specificity phosphatase 14 (DUSP14), which we identify as an OTULIN phosphatase that limits necroptosis. Our data provide evidence of dynamic post-translational modifications of OTULIN and highlight their importance in cell death outcome.

A network pharmacology approach to investigate the mechanism of Shuxuening injection in the treatment of ischemic stroke

ETHNOPHARMACOLOGICAL RELEVANCE

Shuxuening injection (SXNI), a popular herbal medicine, is an extract of Ginkgo biloba leaves (GBE), and is used to treat ischemic stroke (IS) in China. However, its specific active ingredients and molecular mechanisms in IS remain unclear.

AIM OF THE STUDY

The purpose of the research is to identify the main active ingredients in GBE and explore its molecular mechanisms in the treatment of IS.

MATERIALS AND METHODS

The main active components of GBE were discerned through the Traditional Chinese Medicine Systems Pharmacology Database and Analysis (TCMSP), Traditional Chinese Medicine Integrated Database (TCMID), Bioinformatics Analysis Tool for Molecular Mechanism of Traditional Chinese Medicine (BATMAN-TCM) database, and absorption, distribution, metabolism and excretion (ADME) analysis. The targets related to IS were obtained using Genecards, Online Mendelian Inheritance in Man (OMIM), Therapeutic Target Database (TTD), and Disgenet. We discovered an intersection of genes. Subsequently, protein-protein interaction (PPI) networks were constructed with Cytoscape 3.7.1 and the String database. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed to analyze the intersection of targets via the Database for Annotation, Visualization, and Integrated Discovery (DAVID) 6.8. Built on the above analysis, we made a Compound-Target-Pathway (C-T-P) network. Autodock Vina was used for molecular docking analysis. Maestro 11.9 was used to calculate the root-mean-square deviation (RMSD). Animal experiments were performed to verify the core targets. Triphenyl tetrazolium chloride (TTC) staining was used to calculate the infarct volume in rats. Hematoxylin-eosin (HE) staining was employed to observe the morphology of hippocampal neuron cells. RT-qPCR was applied to detect relative mRNA levels, and protein expression was determined using Western blotting.

RESULTS

Molecular docking showed that PTGS2, NOS3 and CASP3 docked with small molecule compounds. According to RT-qPCR and Western blotting, mRNA and protein expression of PTGS2 and CASP3 were up-regulated (P < 0.05), and mRNA and protein levels of NOS3 were down-regulated (P < 0.05).

CONCLUSIONS

SXNI can treat IS through multiple targets and routes, and reduce the apoptosis of neuron cells in brain tissue by inhibiting inflammation and regulating the level of oxidative stress, thereby protecting rats brain tissue.

Inhibition of IL-32 Expression Ameliorates Cerebral Ischemia-Reperfusion Injury via the NOD/MAPK/NF-κB Signaling Pathway

Cerebral ischemia represents a major cause of disability, yet its precise mechanism remains unknown. In addition, ischemia-reperfusion injury which occurs during the blood recovery process increases the risk of mortality, and is not adequately addressed with current treatment. To improve therapeutic options, it is important to explore the vital substances that play a pivotal role in ischemia-reperfusion injury. This study is the first to investigate the role of IL-32, a vital pro-inflammatory factor, in models of cerebral ischemia-reperfusion injury. The results showed that IL-32 was highly expressed in both in vivo and in vitro models. The proteins of the NOD/MAPK/NF-κB pathway were also up-regulated, indicating a potential signaling pathway mechanism. Inhibition of IL-32 and blocking of the NOD/MAPK/NF-κB pathway increased cell survival, decreased the level of inflammatory factors and inflammasomes, and attenuated nitrosative stress. Taken together, the results show that inhibition of IL-32 expression ameliorates cerebral ischemia-reperfusion injury via the NOD/MAPK/NF-κB signaling pathway. The findings in this study reveal that IL-32 is a vital target of ischemia-reperfusion injury, providing a new avenue for treatment development.

Neuroprotective effects of minocycline on focal cerebral ischemia injury: a systematic review

To review the neuroprotective effects of minocycline in focal cerebral ischemia in animal models. By searching in the databases of PubMed, ScienceDirect, and Scopus, and considering the inclusion and exclusion criteria of the study. Studies were included if focal cerebral ischemia model was performed in mammals and including a control group that has been compared with a minocycline group. Written in languages other than English; duplicate data; in vitro studies and combination of minocycline with other neuroprotective agents were excluded. Neurological function of patients was assessed by National Institute of Health Stroke Scale, modified Rankin Scale, and modified Barthel Index. Neuroprotective effects were assessed by detecting the expression of inflammatory cytokines. We examined 35 papers concerning the protective effects of minocycline in focal cerebral ischemia in animal models and 6 clinical trials which had evaluated the neuroprotective effects of minocycline in ischemic stroke. These studies revealed that minocycline increases the viability of neurons and decreases the infarct volume following cerebral ischemia. The mechanisms that were reported in these studies included anti-inflammatory, antioxidant, as well as anti-apoptotic effects. Minocycline also increases the neuronal regeneration following cerebral ischemia. Minocycline has considerable neuroprotective effects against cerebral ischemia-induced neuronal damages. However, larger clinical trials may be required before using minocycline as a neuroprotective drug in ischemic stroke.