Interaction between inducible nitric oxide synthase and cyclooxygenase-2 after cerebral ischemia

Novel Therapeutic Effects of Euphorbia heterophylla L. Methanol Extracts in Macular Degeneration Caused by Blue Light in A2E-Laden ARPE-19 Cells and Retina of BALB/c Mice

Natural products with high antioxidant activity are considered as innovative prevention strategies to effectively prevent age-related macular degeneration (AMD) in the early stage because the generation of reactive oxygen species (ROS) leading to the development of drusen is reported as an important cause of this disease. To investigate the prevention effects of the methanol extracts of Euphorbia heterophylla L. (MEE) on AMD, its effects on the antioxidant activity, inflammatory response, apoptosis pathway, neovascularization, and retinal tissue degeneration were analyzed in N-retinylidene-N-retinylethanolamine (A2E)-landed spontaneously arising retinal pigment epithelia (ARPE)-19 cells and BALB/c mice after exposure to blue light (BL). The MEE contained 10 active components and showed high free radical scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and nitric oxide (NO) radicals. The pretreatments of high-dose MEE remarkably suppressed the production of intracellular ROS (88.2%) and NO (25.2%) and enhanced (SOD) activity (84%) and the phosphorylation of nuclear factor erythroid 2-related factor 2 (Nrf2) in A2E + BL-treated ARPE-19 cells compared to Vehicle-treated group. The activation of the inducible nitric oxide synthase (iNOS)-induced cyclooxygenase-2 (COX-2) mediated pathway, inflammasome activation, and expression of inflammatory cytokines was significantly inhibited in A2E + BL-treated ARPE-19 cells after the MEE pretreatment. The activation of the apoptosis pathway and increased expression of neovascular proteins (36% for matrix metalloproteinase (MMP)-9) were inhibited in the MEE pretreated groups compared to the Vehicle-treated group. Furthermore, the thickness of the whole retina (31%), outer nuclear layer (ONL), inner nuclear layer (INL), and photoreceptor layer (PL) were significantly increased by the MEE pretreatment of BALB/c mice with BL-induced retinal degeneration. Therefore, these results suggest that the MEE, with its high antioxidative activity, protects against BL-induced retinal degeneration through the regulation of the antioxidative system, inflammatory response, apoptosis, and neovascularization in the AMD mouse model.

Neurodegenerative effects of air pollutant Particles: Biological mechanisms implicated for Early-Onset Alzheimer's disease

BACKGROUND

Sporadic Alzheimer's disease (AD) occurs in 99% of all cases and can be influenced by air pollution such as diesel emissions and more recently, an iron oxide particle, magnetite, detected in the brains of AD patients. However, a mechanistic link between air pollutants and AD development remains elusive.

AIM

To study the development of AD-relevant pathological effects induced by air pollutant particle exposures and their mechanistic links, in wild-type and AD-predisposed models.

METHODS

C57BL/6 (n = 37) and APP/PS1 transgenic (n = 38) mice (age 13 weeks) were exposed to model pollutant iron-based particle (Fe0-Fe3O4, dTEM = 493 ± 133 nm), hydrocarbon-based diesel combustion particle (43 ± 9 nm) and magnetite (Fe3O4, 153 ± 43 nm) particles (66 µg/20 µL/third day) for 4 months, and were assessed for behavioural changes, neuronal cell loss, amyloid-beta (Aβ) plaque, immune response and oxidative stress-biomarkers. Neuroblastoma SHSY5Y (differentiated) cells were exposed to the particles (100 μg/ml) for 24 h, with assessments on immune response biomarkers and reactive oxygen species generation.

RESULTS

Pollutant particle-exposure led to increased anxiety and stress levels in wild-type mice and short-term memory impairment in AD-prone mice. Neuronal cell loss was shown in the hippocampal and somatosensory cortex, with increased detection of Aβ plaque, the latter only in the AD-predisposed mice, with the wild-type not genetically disposed to form the plaque. The particle exposures however, increased AD-relevant immune system responses, including inflammation, in both strains of mice. Exposures also stimulated oxidative stress, although only observed in wild-type mice. The in vitro studies complemented the immune response and oxidative stress observations.

CONCLUSIONS

This study provides insights into the mechanistic links between inflammation and oxidative stress to pollutant particle-induced AD pathologies, with magnetite apparently inducing the most pathological effects. No exacerbation of the effects was observed in the AD-predisposed model when compared to the wild-type, indicating a particle-induced neurodegeneration that is independent of disease state.

A New Approach for Exploring Reperfusion Brain Damage in Hypoxic Ischemic Encephalopathy

Reperfusion is an essential pathological stage in hypoxic ischemic encephalopathy (HIE). Although the Rice-Vannucci model is widely used in HIE research, it remains difficult to replicate HIE-related reperfusion brain injury. The purpose of this study is to establish a rat model of hypoxia ischemia reperfusion brain damage (HIRBD) using a common carotid artery (CCA) muscle bridge in order to investigate the mechanisms of cerebral resistance to hypoxic-ischemic and reperfusion brain damage. Random assignment of Sprague-Dawley (SD) rats to the Sham, HIRBD, and Rice-Vannucci groups. Changes in body weight, mortality rate, spontaneous alternation behavior test (SAB test), and dynamic changes in cerebral blood flow (CBF) were detected. The damaged cerebral cortices were extracted for morphological comparison, transcriptomic analysis, and quantitative real-time PCR. Harvesting the hippocampus for transmission electron microscopy (TEM) detection. As a result, CCA muscle bridge could effectively block CBF, which recovered after the muscle bridge detachment. Pathological comparison, the SAB test, and TEM analysis revealed that brain damage in Rice-Vannucci was more severe than HIRBD. Gpx1, S100a6, Cldn5, Esr1, and Gfap were highly expressed in both HIRBD and Rice-Vannucci. In conclusion, the CCA muscle bridge-established HIRBD model could be used as an innovative and dependable model to simulate pathological process of HIRBD.

Dielectrophoretic force-induced wrinkling of graphene oxide: Enhancing electrical conductivity and expanding biosensing applications

Graphene oxide (GO) has many advantages, making it suitable for various applications. However, it has low electrical conductivity, restricting its applicability to electrochemical biosensors. This study used dielectrophoretic (DEP) force to control the movement and deformation of GO nanosheets to achieve high electrical conductivity without the chemical reduction of oxygen functional groups. Subjecting the DEP force to GO nanosheets induced physical deformation leading to the formation of wrinkled structures. A computational simulation was performed to set an appropriate electrical condition for operating a positive DEP force effect of at least 1019 v2/m3, and the interdigitated microelectrode structure was selected. The resulting wrinkled GO exhibited significantly improved electrical conductivity, reaching 21.721 μS while preserving the essential oxygen functional groups. Furthermore, a biosensor was fabricated using wrinkled GO deposited via DEP force. The biosensor demonstrated superior sensitivity, exhibiting a 9.6-fold enhancement compared with reduced GO (rGO) biosensors, as demonstrated through biological experiments targeting inducible nitric oxide synthase. This study highlights the potential of using DEP force to enhance electrical conductivity in GO-based biosensing applications, opening new avenues for high-performance diagnostics.

Stimulation of Angiotensin II Type 2 Receptor Modulates Pro-Inflammatory Response in Microglia and Macrophages: Therapeutic Implications for the Treatment of Stroke

BACKGROUND

Sustained microglial activation contributes to the development of post-stroke cognitive impairment (PSCI). Compound 21 (C21), an angiotensin II type 2 receptor agonist, has shown some neurovascular protection after stroke. This study aimed to investigate the direct anti-inflammatory effects of C21 on macrophages, as well as brain innate immune cells.

METHODS

Murine microglial cell line (C8-B4) and RAW 264.7 macrophages were exposed to lipopolysaccharide (LPS) and co-treated with C21. Pro-inflammatory mediators were assessed via RT-qPCR and ELISA. Cellular reactive oxygen species (ROS) were evaluated via CellROXGreen staining, and nitrate production was assessed using Griess assay.

RESULTS

C21 suppressed LPS-induced inflammation and ROS generation in both cells. In microglia, C21 blunted LPS-induced mRNA expression of IL-1β, IL-12b, COX-1, iNOS, and IL-6. A similar pattern was observed in macrophages, where C21 suppressed LPS-induced IL-1β, TNF-α, and CXCL1 expression. These anti-inflammatory effects in microglia and macrophages were associated with increased neuroprotective gene expression, including GDNF and BDNF, in a dose-dependent manner.

CONCLUSIONS

Our findings suggest a protective effect of C21 against the inflammatory response, in both macrophages and microglia, via suppression of the release of pro-inflammatory cytokines/chemokines and the generation of ROS while stimulating the production of neurotrophic factors.

Microbiota-derived short-chain fatty acids: Implications for cardiovascular and metabolic disease

Cardiovascular diseases (CVDs) have been on the rise around the globe in the past few decades despite the existing guidelines for prevention and treatment. Short-chain fatty acids (SCFAs) are the main metabolites of certain colonic anaerobic bacterial fermentation in the gastrointestinal tract and have been found to be the key metabolites in the host of CVDs. Accumulating evidence suggest that the end-products of SCFAs (including acetate, propionate, and butyrate) interact with CVDs through maintaining intestinal integrity, anti-inflammation, modulating glucolipid metabolism, blood pressure, and activating gut-brain axis. Recent advances suggest a promising way to prevent and treat CVDs by controlling SCFAs. Hence, this review tends to summarize the functional roles carried out by SCFAs that are reported in CVDs studies. This review also highlights several novel therapeutic interventions for SCFAs to prevent and treat CVDs.

Commercial Hormone Replacement Therapy Jeopardized Proinflammatory Factors in Experimental Rat Models

BACKGROUND: Hormonal contraceptive therapy is considered the easiest and most convenient contraceptive method. Commercially, available contraceptive combination differs in their composition and concentration of combined constituents. These variations make some of these products preferred over others by consumers based on their side effects profile. AIM: The objective of the current research was to ascertain the proinflammatory influences of commercially available products. METHODS: To do so, five groups of rats (ten rats in each group) were exposed to Microgynon, Depo-Provera, marvel on, and Yasmin compared to the control non-treated group. We measured proinflammatory markers including d-dimer, TNF-α (tumor necrosis factor-alpha), IL (interleukin)-6, IL (interleukin)-1B, and c-reactive protein. RESULTS: The results confirmed that Yasmin has induced the most deleterious effects on proinflammatory markers indicated by significant elevation of IL1B. CONCLUSION: Hormone replacement therapy should be critically indicated and precautions raised inpatient with subclinical diseases, especially cardiovascular ones.

PARP inhibitor PJ34 ameliorates cognitive impairments induced by transient cerebral ischemia/reperfusion through its anti-inflammatory effects in a rat model

Cerebral ischemia is a major health threat to humankind around the world, and the reperfusion methods may provoke irreversible damages to brain tissues, causing impairment of neurological function. The goal of this study is to investigate the potential neurological protective effect of PJ34, a well-characterized poly (ADP-ribose) polymerase 1 (PARP-1) inhibitor, on cerebral ischemia-reperfusion (I/R)-induced injury of the rat model. The cerebral I/R rats were received (3, 6, or 12 mg/kg) injections of PJ34 or saline at 24 h, 6 h before middle cerebral artery occlusion (MCAO) and 1 h, 24 h, and 48 h after MCAO. All rats were subject to the neurological behavior tests by open field test and Morris water maze test. The expression of pro-inflammatory cytokines, Cyclooxygenase 2 (COX-2) and inducible nitric oxide synthase (iNOS) in cerebral tissues was also determined. Our results demonstrated that the administration of PJ34 dose-dependently ameliorated cerebral I/R-induced injury and improved neurological performance of cerebral I/R rats. We also revealed that PJ34 treatment effectively reduced COX2, iNOS, and pro-inflammatory cytokine levels in the I/R-induced injury tissues. Our finding further supports that inhibition of PARP-1 activity is beneficial for reducing post-I/R-induced brain damage via targeting inflammatory response.

Inhibition of neuroinflammatory nitric oxide signaling suppresses glycation and prevents neuronal dysfunction in mouse prion disease

Several neurodegenerative diseases associated with protein misfolding (Alzheimer's and Parkinson's disease) exhibit oxidative and nitrergic stress following initiation of neuroinflammatory pathways. Associated nitric oxide (NO)-mediated posttranslational modifications impact upon protein functions that can exacerbate pathology. Nonenzymatic and irreversible glycation signaling has been implicated as an underlying pathway that promotes protein misfolding, but the direct interactions between both pathways are poorly understood. Here we investigated the therapeutic potential of pharmacologically suppressing neuroinflammatory NO signaling during early disease progression of prion-infected mice. Mice were injected daily with an NO synthase (NOS) inhibitor at early disease stages, hippocampal gene and protein expression levels of oxidative and nitrergic stress markers were analyzed, and electrophysiological characterization of pyramidal CA1 neurons was performed. Increased neuroinflammatory signaling was observed in mice between 6 and 10 wk postinoculation (w.p.i.) with scrapie prion protein. Their hippocampi were characterized by enhanced nitrergic stress associated with a decline in neuronal function by 9 w.p.i. Daily in vivo administration of the NOS inhibitor L-NAME between 6 and 9 w.p.i. at 20 mg/kg prevented the functional degeneration of hippocampal neurons in prion-diseased mice. We further found that this intervention in diseased mice reduced 3-nitrotyrosination of triose-phosphate isomerase, an enzyme involved in the formation of disease-associated glycation. Furthermore, L-NAME application led to a reduced expression of the receptor for advanced glycation end-products and the diminished accumulation of hippocampal prion misfolding. Our data suggest that suppressing neuroinflammatory NO signaling slows functional neurodegeneration and reduces nitrergic and glycation-associated cellular stress.

The inhibition of mammalian target of rapamycin (mTOR) in improving inflammatory response after traumatic brain injury

Traumatic brain injury (TBI) provokes primary and secondary damage on endothelium and brain parenchyma, leading neurons die rapidly by necrosis. The mammalian target of rapamycin signalling pathway (mTOR) manages numerous aspects of cellular growth, and it is up-regulated after moderate to severe traumatic brain injury (TBI). Currently, the significance of this increased signalling event for the recovery of brain function is unclear; therefore, we used two different selective inhibitors of mTOR activity to discover the functional role of mTOR inhibition in a mouse model of TBI performed by a controlled cortical impact injury (CCI). Treatment with KU0063794, a dual mTORC1 and mTORC2 inhibitor, and with rapamycin as well-known inhibitor of mTOR, was performed 1 and 4 hours subsequent to TBI. Results proved that mTOR inhibitors, especially KU0063794, significantly improved cognitive and motor recovery after TBI, reducing lesion volumes. Also, treatment with mTOR inhibitors ameliorated the neuroinflammation associated with TBI, showing a diminished neuronal death and astrogliosis after trauma. Our findings propose that the involvement of selective mTORC1/2 inhibitor may represent a therapeutic strategy to improve recovery after brain trauma.

Essential oil, juice, and ethanol extract from bergamot confer improving effects against primary dysmenorrhea in rats

Primary dysmenorrhea (PD) is one of the most common gynecological disorders among young women. Bergamot is rich in natural bioactive ingredients, which could potentially ameliorate PD. We aimed to investigate whether the bergamot products (essential oil, juice, and ethanol extract) could improve PD induced by estradiol benzoate and oxytocin. The rats were supplemented with the three doses of bergamot products and positive drugs by gastric perfusion, respectively. The results demonstrated that bergamot products could alleviate PD with dose-dependence via inhibiting the growth of PGF_{2 α} /PGE₂ ratio, accumulation of MDA, and release of iNOS, and promoting the activities of T-AOC, SOD, CAT, and GSH in uterine tissues. Furthermore, bergamot products could mitigate the writhing response and histopathological alterations in uterine tissues. In addition, bergamot essential oil had greater benefits than the corresponding dose of juice and ethanol extract. PRACTICAL APPLICATIONS: An increasing number of young women suffered PD, severely impacting their life. Seeking a healthy diet therapy can effectively avoid the adverse effects of PD drugs. Bergamot as natural fruit is rich in several bioactive ingredients. This study reported the function of bergamot products for alleviating PD via regulating the levels of prostaglandins and inflammatory mediator, and the capacities of antioxidants. This research provides insights for the development of functional foods with improving effect against PD. It also offers us a theoretical basis for the reasonable application of different forms of bergamot products.

Inhibitors of Src Family Kinases, Inducible Nitric Oxide Synthase, and NADPH Oxidase as Potential CNS Drug Targets for Neurological Diseases

Neurological diseases share common neuroinflammatory and oxidative stress pathways. Both phenotypic and molecular changes in microglia, astrocytes, and neurons contribute to the progression of disease and present potential targets for disease modification. Src family kinases (SFKs) are present in both neurons and glial cells and are upregulated following neurological insults in both human and animal models. In neurons, SFKs interact with post-synaptic protein domains to mediate hyperexcitability and neurotoxicity. SFKs are upstream of signaling cascades that lead to the modulation of neurotransmitter receptors and the transcription of pro-inflammatory cytokines as well as producers of free radicals through the activation of glia. Inducible nitric oxide synthase (iNOS/NOS-II) and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 2 (NOX2), the major mediators of reactive nitrogen/oxygen species (RNS/ROS) production in the brain, are also upregulated along with the pro-inflammatory cytokines following neurological insult and contribute to disease progression. Persistent neuronal hyperexcitability, RNS/ROS, and cytokines can exacerbate neurodegeneration, a common pathognomonic feature of the most prevalent neurological disorders such as Alzheimer's disease, Parkinson's disease, and epilepsy. Using a wide variety of preclinical disease models, inhibitors of the SFK-iNOS-NOX2 signaling axis have been tested to cure or modify disease progression. In this review, we discuss the SFK-iNOS-NOX2 signaling pathway and their inhibitors as potential CNS targets for major neurological diseases.

Therapeutic potential of mangiferin in the treatment of various neuropsychiatric and neurodegenerative disorders

Xanthones are important chemical class of bioactive products that confers therapeutic benefits. Of several xanthones, mangiferin is known to be distributed widely across several fruits, vegetables and medicinal plants. Mangiferin has been shown to exert neuroprotective effects in both in-vitro and in-vivo models. Mangiferin attenuates cerebral infarction, cerebral edema, lipid peroxidation (MDA), neuronal damage, etc. Mangiferin further potentiate levels of endogenous antioxidants to confer protection against the oxidative stress inside the neurons. Mangiferin is involved in the regulation of various signaling pathways that influences the production and levels of proinflammatory cytokines in brain. Mangiferin cosunteracted the neurotoxic effect of amyloid-beta, MPTP, rotenone, 6-OHDA etc and confer protection to neurons. These evidence suggested that the mangiferin may be a potential therapeutic strategy for the treatment of various neurological disorders. The present review demonstrated the pharmacodynamics-pharmacokinetics of mangiferin and neurotherapeutic potential in several neurological disorders with underlying mechanisms.

Loss of Collapsin Response Mediator Protein 4 Attenuates 6-Hydroxydopamine-Induced Impairments in a Mouse Model of Parkinson's Disease

Parkinson's disease (PD) is a chronic neurodegenerative disorder characterized by impaired motor symptoms induced by the degeneration of dopaminergic neurons of the substantia nigra pars compacta (SNc). Many factors are speculated to operate in the mechanism of PD, including oxidative stress, mitochondrial dysfunction, abnormal protein handling, and PD induced apoptosis. Besides, researchers have recently shown that inflammatory secretions may engage neighboring cells such as astrocytes, which then induce autocrine and paracrine responses that amplify the inflammation, leading to neurodegeneration. In the present study, we analyzed the neuroprotective and anti-inflammatory effects of collapsin response mediator protein 4 (CRMP4) deletion in 6-hydroxydopamine (6-OHDA)-injected male mice, as well as its effects on motor impairments. Our findings indicated that the deletion of CRMP4 could maintain the TH-positive fibers in the striatum and the TH-positive cells in SNc, attenuate the inflammatory responses, and improve motor coordination and rotational behavior. Furthermore, based on our findings at the early time points, we hypothesized that primary differences between the Crmp4+/+ and Crmp4-/- mice may occur in microglia instead of neurons. Although further work should be carried out to clarify the specific role of CRMP4 in the pathogenesis of PD, our findings suggest that it could be a possible target for the treatment of PD.

Quantitative Proteomics Reveals the Beneficial Effects of Low Glucose on Neuronal Cell Survival in an in vitro Ischemic Penumbral Model

Understanding proteomic changes in the ischemic penumbra are crucial to rescue those salvageable cells and reduce the damage of an ischemic stroke. Since the penumbra region is dynamic with heterogeneous cells/tissues, tissue sampling from animal models of stroke for the molecular study is a challenge. In this study, cultured hippocampal HT22 cells under hypoxia treatment for 17.5 h with 0.69 mM low glucose (H+LG) could mimic ischemic penumbral cells since they had much higher cell viability and viable cell number compared to hypoxia without glucose (H-G) treatment. To validate established cell-based ischemic penumbral model and understand the beneficial effects of low glucose (LG), quantitative proteomics analysis was performed on H+LG, H-G, and normoxia with normal 22 mM glucose (N+G) treated cells. We identified 427 differentially abundant proteins (DAPs) between H-G and N+G and further identified 105 DAPs between H+LG and H-G. Analysis of 105 DAPs revealed that LG promotes cell survival by activating HIF1α to enhance glycolysis; preventing the dysregulations of extracellular matrix remodeling, cell cycle and division, and antioxidant and detoxification; as well as attenuating inflammatory reaction response, protein synthesis and neurotransmission activity. Our results demonstrated that this established cell-based system could mimic penumbral conditions and can be used for molecular studies.

Combinational effect of curcumin and metformin against gentamicin-induced nephrotoxicity: Involvement of antioxidative, anti-inflammatory and antiapoptotic pathway

Gentamicin (GM) is an antibiotic related to aminoglycoside group that is used in treating Gram-negative bacterial infections. However, treatment with gentamicin is considered to be limited as it induces an oxidative stress-mediated apoptosis in kidney which causes a nephrotoxicity. Metformin is a well-known biguanide that is used for treating diabetes mellitus, especially type 2. Supplement with plant metabolites or natural antioxidants produce a protective activity against many types of diseases in vivo. Curcumin is a main medicinal constituent of Curcuma longa, has reported for number of biological effects, such as antioxidant, anti-inflammatory, and antitumor. The study aims at evaluating the metformin and curcumin alone or in combination on nephrotoxicity induced by GM. The outcome of the study shows that both metformin and curcumin, when used unaided, were effectively decreasing GM-induced nephrotoxicity. The two drugs combination was showed synergistic effect in ameliorating a GM-induced kidney injury, as supported by expressively improved renal dysfunction. Metformin and curcumin showed strong protection against oxidative stress in GM treated animals through decreasing the activities and expression of various antioxidative enzymes. Moreover, combination of two drugs showed an anti-inflammatory response through reducing a level of pro-inflammatory cytokines including tumor necrosis factor-alpha, interleukin 1-beta, and interleukin 6 in GM intoxicated group of animals. Furthermore, GM agitated apoptosis was affectedly diminished by the combinational treatment of metformin and curcumin via down-regulating activity of cleaved Caspase-3 and pro-apoptotic factor Bax, whereas increasing anti-apoptotic factor Bcl-2 signaling pathways. The above results suggested that combinational treatment of metformin and curcumin might be have a synergizing effect and substantial potential against nephrotoxicity induced by GM. PRACTICAL APPLICATIONS: Curcumin and metformin combination exhibited substantial synergistic effect against GM-induced nephrotoxicity through reducing oxidative stress, inflammation, as well as apoptosis in kidney cells. Therefore, the method of combination of curcumin and metformin might be functional to treat or inhibit GM prompted nephrotoxicity in future.

Gelatin-Coated Polycaprolactone Nanoparticle-Mediated Naringenin Delivery Rescue Human Mesenchymal Stem Cells from Oxygen Glucose Deprivation-Induced Inflammatory Stress

Ischemic stroke involves pro-inflammatory species, which implicates inflammation in the disease mechanism. Recent studies indicate that the prevalence of therapeutic choice such as stem cell transplantation has seen an upsurge in ischemic stroke. However, after transplantation the fate of transplanted cells is largely unknown. Human mesenchymal stem cells (MSCs), due to their robust survival rate upon transplantation in brain tissue, are being widely employed to treat ischemic stroke. In the present study, we have evaluated naringenin-loaded gelatin-coated polycaprolactone nanoparticles (nar-gel-c-PCL NPs) to rescue MSCs against oxygen glucose deprived insult. Naringenin, due to its strong anti-inflammatory effects, remains a therapeutic choice in neurological disorders. Though, the low solubility and inefficient delivery remain challenges in using naringenin as a therapeutic drug. The present study showed that inflammation occurred in MSCs during their treatment with oxygen glucose deprivation (OGD) and was well overturned by treatment with nar-gel-c-PCL NPs. In brief, the results indicated that nar-gel-c-PCL NPs were able to protect the loss of cell membrane integrity and restored neuronal morphology. Then nar-gel-c-PCL NPs successfully protected the human MSCs against OGD-induced inflammation as evident by reduced level of pro-inflammatory cytokine (TNF-α, IFN-γ, and IL-1β) and other inflammatory biomarkers (COX2, iNOS, and MPO activity). Therefore, the modulation of inflammation by treatment with nar-gel-c-PCL NPs in MSCs could provide a novel strategy to improve MSC-based therapy, and thus, our nanoformulation may find a wide therapeutic application in ischemic stroke and other neuro-inflammatory diseases.

Regulation of Cell Survival, Apoptosis, and Epithelial-to-Mesenchymal Transition by Nitric Oxide-Dependent Post-Translational Modifications

SIGNIFICANCE

Nitric oxide (NO) is a physiopathological messenger generating different reactive nitrogen species (RNS) according to hypoxic, acidic and redox conditions. Recent Advances: RNS and reactive oxygen species (ROS) promote relevant post-translational modifications, such as nitrosation, nitration, and oxidation, in critical components of cell proliferation and death, epithelial-to-mesenchymal transition, and metastasis.

CRITICAL ISSUES

The pro- or antitumoral properties of NO are dependent on local concentration, redox state, cellular status, duration of exposure, and compartmentalization of NO generation. The increased expression of NO synthase has been associated with cancer progression. However, the experimental strategies leading to high intratumoral NO generation have been shown to exert antitumoral properties. The effect of NO and ROS on cell signaling is critically altered by factors modulating tumor progression such as oxygen content, metabolism, and inflammatory response. The review describes the alteration of key components involved in cell survival and death, metabolism, and metastasis induced by RNS- and ROS-related post-translational modifications.

FUTURE DIRECTIONS

The identification of the molecular targets affected by nitrosation, nitration, and oxidation, as well as their interactions with other post-translational modifications, will improve the understanding on the complex signaling and cell fate decision in cancer. The therapeutic NO-based strategies have to address the complex crosstalk among NO and ROS with regard to critical components affecting tumor cell survival, metabolism, and metastasis in the progression of cancer, as well as close interaction with ionizing radiation and chemotherapy.

Hypothermia and brain inflammation after cardiac arrest

The cessation (ischemia) and restoration (reperfusion) of cerebral blood flow after cardiac arrest (CA) induce inflammatory processes that can result in additional brain injury. Therapeutic hypothermia (TH) has been proven as a brain protective strategy after CA. In this article, the underlying pathophysiology of ischemia-reperfusion brain injury with emphasis on the role of inflammatory mechanisms is reviewed. Potential targets for immunomodulatory treatments and relevant effects of TH are also discussed. Further studies are needed to delineate the complex pathophysiology and interactions among different components of immune response after CA and identify appropriate targets for clinical investigations.

Free Radical Damage in Ischemia-Reperfusion Injury: An Obstacle in Acute Ischemic Stroke after Revascularization Therapy

Acute ischemic stroke is a common cause of morbidity and mortality worldwide. Thrombolysis with recombinant tissue plasminogen activator and endovascular thrombectomy are the main revascularization therapies for acute ischemic stroke. However, ischemia-reperfusion injury after revascularization therapy can result in worsening outcomes. Among all possible pathological mechanisms of ischemia-reperfusion injury, free radical damage (mainly oxidative/nitrosative stress injury) has been found to play a key role in the process. Free radicals lead to protein dysfunction, DNA damage, and lipid peroxidation, resulting in cell death. Additionally, free radical damage has a strong connection with inducing hemorrhagic transformation and cerebral edema, which are the major complications of revascularization therapy, and mainly influencing neurological outcomes due to the disruption of the blood-brain barrier. In order to get a better clinical prognosis, more and more studies focus on the pharmaceutical and nonpharmaceutical neuroprotective therapies against free radical damage. This review discusses the pathological mechanisms of free radicals in ischemia-reperfusion injury and adjunctive neuroprotective therapies combined with revascularization therapy against free radical damage.

Pre-treated theaflavin-3,3'-digallate has a higher inhibitory effect on the HCT116 cell line

The pro-apoptotic and inhibitory effects of the aflavin-3,3′-digallate (TFDG), which is the typical pigment in black tea, have been demonstrated in many cancer cell lines. However, TFDG is not stable in general culture conditions. So, to what extent TFDG or which degradation products of TFDG play an antitumor role is still unclear. In this study, we evaluated the effect of different treatments of TFDG on HCT116 cells. Compared with the control, both TFDG and O-TFDG (the TFDG that was pre-incubated in an incubator at 37°C for 3 hbefore adding into 96-well plates) significantly inhibited HCT116 cell growth. However, pre-treated TFDG was far better than TFDG. The IC50 values of TFDG and O-TFDG-3 were 17.26 μM and 8.98 μM, respectively (the cells were treated by O-TFDG for only 3 h, after which the media were replaced by fresh media for another 69 h incubation). Cell-cycle analysis revealed that 20 μM of O-TFDG and O-TFDG-3 caused cell-cycle arrest at G2 phase in HCT116 cells. Western blot analysis also demonstrated that the anti-inflammatory effect of O-TFDG-3 is stronger than that of TFDG by decreasing COX-2 and iNOS. On the other hand, O-TFDG induced HCT116 cells apoptosis mainly by increasing the expression of p53, p21, and cleaved caspase-3. The current study demonstrated that O-TFDG had a higher inhibitory effect on HCT116 cells than TFDG, and sowe may inferfromthis that the degradation products of TFDG play a key role against tumors.

Roles of nitric oxide and ethyl pyruvate after peripheral nerve injury

Short-lived reactive nitrogen species and reactive oxygen species have acquired significant attention in the field of biomedical science. Nitric oxide (NO), which was thought to be an unstable gas and pollutant, is now regarded as a gas transmitter like H2S and CO. NO is synthesized inside the mammalian body by l-arginine via three different isoforms of NO synthase whereas pyruvate is a glycolysis product and substrate for TCA cycle. Due to poor solubility and stability, therapeutic potential of pyruvate is limited. Ethyl pyruvate (EP) is now considered as a suitable replacement of pyruvate. In this paper, we will try to focus the effect of NO and EP in Schwann cell dedifferentiation, proliferation, nerve degeneration, and regeneration during Wallerian degeneration (WD) of peripheral nerve injury along with their neuroprotective effects, cardiovascular functioning, support in hepatic complication, etc.

Mesenchymal Stem Cell-Derived Extracellular Vesicles Ameliorates Hippocampal Synaptic Impairment after Transient Global Ischemia

Recent studies have found that administration of stem cells or extracellular vehicles (EVs) derived from stem cells exert neuroprotective effects after transient global ischemia. However, the underlying mechanisms of this effect remain unclear, especially at the level of synaptic functions. In this study, we compared the suppressive effects on cyclooxygenase-2 (COX-2) upregulation by EVs derived from bone marrow mesenchymal stem cells (BMSC-EV), adipose tissue MSC (AdMSC-EV) and serum (serum-EV). Then we examined whether BMSC-EVs could restore functional integrity of synaptic transmission and plasticity. Mice were randomly assigned to four groups: sham, sham with EV treatment, ischemia and ischemia with EV treatment. EVs were administered by intracerebroventricular injection (ICVI). We examined the consequence of transient global ischemia on pre- and post-synaptic functions of the hippocampal CA3-CA1 synapses at basal level, and long-term potentiation (LTP), an activity-dependent form of synaptic plasticity. Then we tested the therapeutic effects of EVs on these synaptic deficits. Meanwhile, Morris water maze (MWM) test was performed to examine the efficacy of EVs in rescuing ischemia-induced impairments in spatial learning and memory. EV treatment significantly restored impaired basal synaptic transmission and synaptic plasticity, and improved spatial learning and memory compared with the control group. In addition, EVs significantly inhibited ischemia-induced pathogenic expression of COX-2 in the hippocampus. EVs exert ameliorating effects on synaptic functions against transient global cerebral ischemia, which may be partly attributed to suppression of COX-2 pathogenic expression.

Identification and functional characterization of the house finch interleukin-1β

Interleukin-1β (IL-1β), an inflammatory cytokine of the IL-1 family, is primarily produced as a precursor protein by monocytes and macrophages, then matures and becomes activated through proteolytic catalysis. Although the biological characteristics of avian IL-1β are well known, little information is available about its biological role in songbird species such as house finches that are vulnerable to naturally-occurring inflammatory diseases. In this study, house finch IL-1β (HfIL-1β) was cloned, expressed, and its biological function examined. Both precursor and mature forms of HfIL-1β consisting of 269 and 162 amino acids, respectively, were amplified from total RNA of spleen and cloned into expression vectors. HfIL-1β showed high sequential and tertiary structural similarity to chicken homologue that allowed detection of the expressed mature recombinant HfIL-1β (rHfIL-1β) with anti-ChIL-1β antibody by immunoblot analysis. For further characterization, we used primary splenocytes and hepatocytes that are predominant sources of IL-1β upon stimulation, as well as suitable targets to stimulation by IL-1β. Isolated house finch splenocytes were stimulated with rHfIL-1β in the presence and absence of concanavalin A (Con A), RNA was extracted and transcript levels of Th1/Th2 cytokines and a chemokine were measured by qRT-PCR. The addition of rHfIL-1β induced significant enhancement of IL-2 transcript, a Th1 cytokine, while transcription of IL-1β and the Th2 cytokine IL-10 was slightly enhanced by rHfIL-1β treatment. rHfIL-1β also led to elevated levels of the chemokine CXCL1 and nitric oxide production regardless of co-stimulation with Con A. In addition, the production of the acute phase protein serum amyloid A and the antimicrobial peptide LEAP2 was observed in HfIL-1β-stimulated hepatocytes. Taken together, these observations revealed the basic functions of HfIL-1β including the stimulatory effect on cell proliferation, production of Th1/Th2 cytokines and acute phase proteins by immune cells, thus providing valuable insight into how HfIL-1β is involved in regulating inflammatory response.

RAGE-TLR Crosstalk Sustains Chronic Inflammation in Neurodegeneration

Chronic inflammatory reactions are consistenly present in neurodegeneration of Alzheimer type and are considered important factors that accelerate progression of the disease. Receptors of innate immunity participate in triggering and driving inflammatory reactions. For example, Toll-like receptors (TLRs) and receptor for advanced glycation end product (RAGE), major receptors of innate immunity, play a central role in perpetuation of inflammation. RAGE activation should be perceived as a primary mechanism which determines self-perpetuated chronic inflammation, and RAGE cooperation with TLRs amplifies inflammatory signaling. In this review, we highlight and discuss that RAGE-TLR crosstalk emerges as an important driving force of chronic inflammation in Alzheimer's disease.

Therapeutic Benefits of Mesenchymal Stromal Cells in a Rat Model of Hemoglobin-Induced Hypertensive Intracerebral Hemorrhage

Previous studies have shown that bone marrow mesenchymal stromal cell (MSC) transplantation significantly improves the recovery of neurological function in a rat model of intracerebral hemorrhage. Potential repair mechanisms involve anti-inflammation, anti-apoptosis and angiogenesis. However, few studies have focused on the effects of MSCs on inducible nitric oxide synthase (iNOS) expression and subsequent peroxynitrite formation after hypertensive intracerebral hemorrhage (HICH). In this study, MSCs were transplanted intracerebrally into rats 6 hours after HICH. The modified neurological severity score and the modified limb placing test were used to measure behavioral outcomes. Blood-brain barrier disruption and neuronal loss were measured by zonula occludens-1 (ZO-1) and neuronal nucleus (NeuN) expression, respectively. Concomitant edema formation was evaluated by H&E staining and brain water content. The effect of MSCs treatment on neuroinflammation was analyzed by immunohistochemical analysis or polymerase chain reaction of CD68, Iba1, iNOS expression and subsequent peroxynitrite formation, and by an enzyme-linked immunosorbent assay of pro-inflammatory factors (IL-1β and TNF-α). The MSCs-treated HICH group showed better performance on behavioral scores and lower brain water content compared to controls. Moreover, the MSC injection increased NeuN and ZO-1 expression measured by immunochemistry/immunofluorescence. Furthermore, MSCs reduced not only levels of CD68, Iba1 and pro-inflammatory factors, but it also inhibited iNOS expression and peroxynitrite formation in perihematomal regions. The results suggest that intracerebral administration of MSCs accelerates neurological function recovery in HICH rats. This may result from the ability of MSCs to suppress inflammation, at least in part, by inhibiting iNOS expression and subsequent peroxynitrite formation.

Comprehensive Insights into the Multi-Antioxidative Mechanisms of Melanin Nanoparticles and Their Application To Protect Brain from Injury in Ischemic Stroke

Nanotechnology-mediated antioxidative therapy is emerging as a novel strategy for treating a myriad of important diseases through scavenging excessive reactive oxygen and nitrogen species (RONS), a mechanism critical in disease development and progression. However, similar to antioxidative enzymes, currently studied nanoantioxidants have demonstrated scavenging activity to specific RONS, and sufficient antioxidative effects against multiple RONS generated in diseases remain elusive. Here we propose to develop bioinspired melanin nanoparticles (MeNPs) for more potent and safer antioxidative therapy. While melanin is known to function as a potential radical scavenger, its antioxidative mechanisms are far from clear, and its applications for the treatment of RONS-associated diseases have yet to be well-explored. In this study, we provide for the first time exhaustive characterization of the activities of MeNPs against multiple RONS including O2•-, H2O2, •OH, •NO, and ONOO-, the main toxic RONS generated in diseases. The potential of MeNPs for antioxidative therapy has also been evaluated in vitro and in a rat model of ischemic stroke. In addition to the broad defense against these RONS, MeNPs can also attenuate the RONS-triggered inflammatory responses through suppressing the expression of inflammatory mediators and cytokines. In vivo results further demonstrate that these unique multi-antioxidative, anti-inflammatory, and biocompatible features of MeNPs contribute to their effective protection of ischemic brains with negligible side effects.

Effects of ginseng on two main sex steroid hormone receptors: estrogen and androgen receptors

Ginseng has been used in China for at least two millennia and is now popular in over 35 countries. It is one of the world's popular herbs for complementary and alternative medicine and has been shown to have helpful effects on cognition and blood circulation, as well as anti-aging, anti-cancer, and anti-diabetic effects, among many others. The pharmacological activities of ginseng are dependent mainly on ginsenosides. Ginsenosides have a cholesterol-like four trans-ring steroid skeleton with a variety of sugar moieties. Nuclear receptors are one of the most important molecular targets of ginseng, and reports have shown that members of the nuclear receptor superfamily are regulated by a variety of ginsenosides. Here, we review the published literature on the effects of ginseng and its constituents on two main sex steroid hormone receptors: estrogen and androgen receptors. Furthermore, we discuss applications for sex steroid hormone receptor modulation and their therapeutic efficacy.

Modulation of the neurological and vascular complications by grape seed extract in a rat model of spinal cord ischemia–reperfusion injury by downregulation of both osteopontin and cyclooxygenase-2

In this study, we investigated the effects of grape seed extract (GSE) on the expression of osteopontin (OPN) and cyclooxygenase-2 (COX-2) in a rat model of spinal cord ischemia–reperfusion injury (SC-IRI). Fifty male rats were divided into 5 groups: control (CON); control + GSE (CON + GSE) (received GSE for 28 days); sham operated (Sham); IRI; and IRI + GSE. SC-IRI was induced by clamping the aorta just above the bifurcation for 45 min, and then the clamp was released for 48 h for reperfusion. IRI + GSE group received GSE for 28 days before SC-IRI. Sensory, motor, and placing/stepping reflex assessment was performed. Prostaglandin E2 (PGE2), thiobarbituric acid reactive substances (TBARs), and total antioxidant capacity (TAC) were measured in spinal cord homogenate. Immunohistochemical examination of the spinal cord for OPN and COX-2 were carried out. SC-IRI resulted in significant increase in plasma nitrite/nitrate level and spinal cord homogenate levels of TBARs and PGE2, and OPN and COX-2 expression with significant decrease in TAC. GSE improves the sensory and motor functions through decreasing OPN and COX-2 expression with reduction of oxidative stress parameters. We conclude a neuroprotective effect of GSE in SC-IRI through downregulating COX-2 and OPN expression plus its antioxidants effects.

Neuroprotective and memory enhancing effects of auraptene in a rat model of vascular dementia: Experimental study and histopathological evaluation

Vascular dementia and Alzheimer disease are most common type of dementia. These diseases have been associated with cognitive decline and affected personal behavioral activities. Moreover, the pattern of cerebral blood flow in mild cognitive disorder has appeared as a predictive indication for the development into Alzheimer's disease. Permanent, bilateral occlusion of the common carotid arteries (2VO) is a standard animal model to study vascular dementia and chronic cerebral hypoperfusion. In present study neuroprotective and memory enhancing effects of auraptene (AUR), a citrus coumarin, were studied in 2VO rats. Different doses (25, 8 & 4mg/kg) of AUR were administered orally. The spatial memory performance was tested with Morris water maze after 2VO induction. Biochemical experiments and histopathological evaluations were also applied to investigate the neuroprotective effect of AUR in brain tissue. In comparison with 2VO group, AUR could significantly decrease the scape latency time in treated rats. Also AUR increased the percentage of time spent and traveled pathway in target quadrant on final trial test day. All behavioral results were confirmed by biochemical and histopathological data. Biochemical data indicated that AUR could decrease malondialdehyde (MDA), as lipid peroxidation indicator, and increase glutathione (GSH) content in cortex and hippocampus tissues. Histopathological data showed that AUR could protect cerebrocortical and hippocampus neurons against ischemia. This study demonstrated the memory enhancing effect and neuroprotective activity of AUR after induction of brain ischemia in a rat model of vascular dementia.

Therapeutic Potential of Natural Product-Based Oral Nanomedicines for Stroke Prevention

Cerebral stroke is the leading cause of death and permanent disability in elderly persons. The impaired glucose and oxygen transport to the brain during ischemia causes bioenergetic failure, leading to oxidative stress, inflammation, blood-brain barrier dysfunction, and eventually cell death. However, the development of effective therapies against stroke has been hampered by insufficient oral absorption of pharmaceuticals and subsequent delivery to the brain. Nanotechnology has emerged as a new method of treating cerebral diseases, with the potential to fundamentally change currently available therapeutic approaches using compounds with low bioavailability. This perspective review provides an overview of the therapeutic potential of oral nanomedicines for stroke, focusing on novel natural product-loaded delivery system with potent antioxidant and anti-inflammatory effects.

Artery-on-a-chip platform for automated, multimodal assessment of cerebral blood vessel structure and function

We present a compact microfluidic platform for the automated, multimodal assessment of intact small blood vessels. Mouse olfactory artery segments were reversibly loaded onto a microfluidic device and kept under physiological (i.e., close to in vivo) environmental conditions. For immunohistochemical endpoint protein analysis, automated on chip fixation and staining of the artery eliminated the need for any subsequent tissue sectioning or processing outside the chip. In a first case study, we demonstrate the blood vessel abluminal structure based on the positions of smooth muscle cell nuclei, actin filaments and voltage gated calcium channels. In a second case study we incubated smooth muscle cells (SMCs) with a calcium-sensitive dye to simultaneously assess time-dependent, agonist-induced calcium and diameter changes of pressurized resistance arteries. We expect the presented microfluidic platform to promote routine on-chip staining and quantitative fluorescence imaging of intact blood vessels from different vascular beds, tissue engineered vascular constructs and vascularized microtissues. The at least tenfold reduction in required aliquot volumes for functional assessment and staining was achieved by on-board fluid manipulation of the syringe-pump free platform and may promote its applications for screening of newly synthesized compounds.

Rational modulation of the innate immune system for neuroprotection in ischemic stroke

The innate immune system plays a dualistic role in the evolution of ischemic brain damage and has also been implicated in ischemic tolerance produced by different conditioning stimuli. Early after ischemia, perivascular astrocytes release cytokines and activate metalloproteases (MMPs) that contribute to blood–brain barrier (BBB) disruption and vasogenic oedema; whereas at later stages, they provide extracellular glutamate uptake, BBB regeneration and neurotrophic factors release. Similarly, early activation of microglia contributes to ischemic brain injury via the production of inflammatory cytokines, including tumor necrosis factor (TNF) and interleukin (IL)-1, reactive oxygen and nitrogen species and proteases. Nevertheless, microglia also contributes to the resolution of inflammation, by releasing IL-10 and tumor growth factor (TGF)-β, and to the late reparative processes by phagocytic activity and growth factors production. Indeed, after ischemia, microglia/macrophages differentiate toward several phenotypes: the M1 pro-inflammatory phenotype is classically activated via toll-like receptors or interferon-γ, whereas M2 phenotypes are alternatively activated by regulatory mediators, such as ILs 4, 10, 13, or TGF-β. Thus, immune cells exert a dualistic role on the evolution of ischemic brain damage, since the classic phenotypes promote injury, whereas alternatively activated M2 macrophages or N2 neutrophils prompt tissue remodeling and repair. Moreover, a subdued activation of the immune system has been involved in ischemic tolerance, since different preconditioning stimuli act via modulation of inflammatory mediators, including toll-like receptors and cytokine signaling pathways. This further underscores that the immuno-modulatory approach for the treatment of ischemic stroke should be aimed at blocking the detrimental effects, while promoting the beneficial responses of the immune reaction.

Coexpression of COX-2 and iNOS in Angiogenesis of Superficial Esophageal Squamous Cell Carcinoma

Using immunohistochemical staining, the present study was conducted to examine whether cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS) affect angiogenesis in early-stage esophageal squamous cell carcinoma (ESCC). We also analyzed the correlation between these two factors. Cyclooxygenase 2, iNOS, and angiogenesis in early-stage ESCC are unclear. Using 10 samples of normal squamous epithelium, 7 samples of low-grade intraepithelial neoplasia (LGIN), and 45 samples of superficial esophageal cancer, we observed the expression of COX-2 and iNOS. We then investigated the COX-2 and iNOS immunoreactivity scores and the correlation between COX-2 or iNOS scores and microvessel density (MVD) using CD34 or CD105. The intensity of COX-2 or iNOS expression differed significantly according to histological type (P < 0.001). The scores of COX-2 and iNOS were lowest for normal squamous epithelium, followed in ascending order by LGIN, carcinoma in situ and tumor invading the lamina propria mucosae (M1-M2 cancer); and tumor invading the muscularis mucosa (M3) or deeper cancer. The differences were significant (P < 0.001). Cancers classified M1-M2 (P < 0.01 and P < 0.05, respectively); M3; or deeper cancer (P < 0.01) had significantly higher COX-2 and iNOS scores than normal squamous epithelium. There was a significant correlation between COX-2 and iNOS scores (P < 0.001, rs = 0.51). Correlations between COX-2 score and CD34-positive MVD or CD105-positive MVD were significant (rs = 0.53, P < 0.001; rs = 0.62, P < 0.001, respectively). Inducible nitric oxide synthase score was also significantly correlated with CD34 MVD and CD105 MVD (rs = 0.45, P < 0.001; rs = 0.60, P < 0.001, respectively). Chemoprevention of COX-2 or iNOS activity may blunt the development of ESCC from precancerous lesions.

A review of in vitro and in vivo studies on the efficacy of herbal medicines for primary dysmenorrhea

Purpose. Primary dysmenorrhea (PD) is a common gynecological complaint among adolescent girls and women of reproductive age. This study aims to review the findings of published articles on the in vitro and in vivo efficacy of herbal medicines for PD. Methods. In vitro and in vivo studies of herbal compounds, individual herbal extracts, or herbal formula decoctions published from their inception to April 2014 were included in this review. Results. A total of 18 studies involving herbal medicines exhibited their inhibitory effect on PD. The majority of in vitro studies investigated the inhibition of uterine contractions. In vivo studies suggest that herbal medicines exert a peripheral analgesic effect and a possible anti-inflammatory activity via the inhibition of prostaglandin (PG) synthesis. The mechanisms of herbal medicines for PD are associated with PG level reduction, suppression of cyclooxygenase-2 expression, superoxide dismutase activation and malondialdehyde reduction, nitric oxide, inducible nitric oxide synthase, and nuclear factor-kappa B reduction, stimulation of somatostatin receptor, intracellular Ca(2+) reduction, and recovery of phospholipid metabolism. Conclusions. Herbal medicines are thought to be promising sources for the development of effective therapeutic agents for PD. Further investigations on the appropriate herbal formula and their constituents are recommended.

Treatment with LPS plus INF-γ induces the expression and function of muscarinic acetylcholine receptors, modulating NIH3T3 cell proliferation: participation of NOS and COX

BACKGROUND AND PURPOSE

LPS and IFN-γ are potent stimuli of inflammation, a process in which fibroblasts are frequently involved. We analysed the effect of treatment with LPS plus IFN-γ on the expression and function of muscarinic acetylcholine receptors in NIH3T3 fibroblasts with regards to proliferation of these cells. We also investigated the participation of NOS and COX, and the role of NF-κB in this process.

EXPERIMENTAL APPROACH

NIH3T3 cells were treated with LPS (10 ng·mL(-1)) plus IFN-γ (0.5 ng·mL(-1)) for 72 h (iNIH3T3 cells). Cell proliferation was evaluated with MTT and protein expression by Western blot analysis. NOS and COX activities were measured by the Griess method and radioimmunoassay respectively.

KEY RESULTS

The cholinoceptor agonist carbachol was more effective at stimulating proliferation in iNIH3T3 than in NIH3T3 cells, probably due to the de novo induction of M3 and M5 muscarinic receptors independently of NF-κB activation. iNIH3T3 cells produced higher amounts of NO and PGE2 than NIH3T3 cells, concomitantly with an up-regulation of NOS1 and COX-2, and with the de novo induction of NOS2/3 in inflamed cells. We also found a positive feedback between NOS and COX that could potentiate inflammation.

CONCLUSIONS AND IMPLICATIONS

Inflammation induced the expression of muscarinic receptors and, therefore,stimulated carbachol-induced proliferation of fibroblasts. Inflammation also up-regulated the expression of NOS and COX-2, thus potentiating the effect of carbachol on NO and PGE2 production. A positive crosstalk between NOS and COX triggered by carbachol in inflamed cells points to muscarinic receptors as potential therapeutic targets in inflammation.

Role of preferential cyclooxygenase-2 inhibition by meloxicam in ischemia/reperfusion injury of the rat liver

BACKGROUND

Ischemia/reperfusion injury (IRI) is one of the major clinical problems in liver and transplant surgery. Livers subjected to warm ischemia in vivo often show a severe dysfunction and the release of numerous inflammatory cytokines and arachidonic acid metabolites. Cyclooxygenase (COX)-2 is the inducible isoform of an intracellular enzyme that converts arachidonic acid into prostaglandins. The aim of the study was to evaluate the effect of COX-2 inhibition and the role of Kupffer cells in IRI of the liver.

METHODS

Male Wistar rats [250- 280 g body weight (BW)] were anesthetized and subjected to 30-min warm ischemia of the liver (Pringle's maneuver) and 60-min reperfusion after median laparotomy. The I/R group received no additional treatment. In the COX-2 inhibitor (COX-2I) group, the animals received 1 mg/kg BW meloxicam prior to operation. Gadolinium chloride (GdCl3) (10 mg/kg BW) was given 24 h prior to operation in the GdCl3 and GdCl3 + COX-2I groups for the selective depletion of Kupffer cells. The GdCl3 + COX-2I group received both GdCl3 and meloxicam treatment prior to operation. Blood and liver samples were obtained at the end of the experiments for further investigations.

RESULTS

After 30 min of warm ischemia in vivo, severe hepatocellular damage was observed in the I/R group. These impairments could be significantly prevented by the selective COX-2 inhibition and the depletion of Kupffer cells. Alanine aminotransferase was significantly reduced upon meloxicam and GdCl3 treatment compared to the I/R group: I/R, 3,240 ± 1,262 U/l versus COX-2I, 973 ± 649 U/l, p < 0.001; I/R versus GdCl3, 1,611 ± 600 U/l, p < 0.05, and I/R versus GdCl3 + COX-2I, 1,511 ± 575 U/l, p < 0.01. Plasma levels of tumor necrosis factor alpha (TNF-α) were significantly reduced in the COX-2I treatment group compared to I/R (3.5 ± 1.5 vs. 16.3 ± 11.7 pg/ml, respectively; p < 0.05). Similarly, the amount of TxB2, a marker for COX-2 metabolism, was significantly reduced in the meloxicam treatment groups compared to the I/R group: I/R, 22,500 ± 5,210 pg/ml versus COX-2I, 1,822 ± 938 pg/ml, p < 0.001, and I/R versus GdCl3 + COX-2I, 1,530 ± 907 pg/ml, p < 0.001. All values are given as mean ± SD (n = 6).

CONCLUSION

These results suggest that the inhibition of COX-2 suppressed the initiation of an inflammatory cascade by attenuating the release of TNF-α, which is an initiator of the inflammatory reaction in hepatic IRI. Therefore, we conclude that preferential inhibition of COX-2 is a possible therapeutic approach against warm IRI of the liver.

Anti-inflammatory effect of D-allose in cerebral ischemia/reperfusion injury in rats

D-allose, a type of rare sugar, can produce inhibitory effects on activated leukocytes in various organs, including immunosuppressive effects and anti-inflammatory effects, as well as anti-oxyradical effects. The present experiment was performed to investigate the potential anti-inflammatory effects of D-allose in acute cerebral ischemia/reperfusion (I/R) injury. Transient middle cerebral artery occlusion model was applied in rats. D-allose was administered two times via a tail vein (300 mg/kg, 1 hour before ischemia and 10 hours after reperfusion). After 22 hours of reperfusion following 2 hours of ischemia, brain damage was evaluated by cerebral infarct volume. Myeloperoxidase (MPO) activity assay by enzyme-linked immunosorbent assay, and protein expression of MPO and cyclooxygenase-2 (COX-2) by immunohistochemistry were evaluated to investigate the potential mechanisms of D-allose. The experimental results showed that D-allose exhibited significant neuroprotective effects against acute cerebral I/R injury. The infarct volume in D-allose-treated rats (90.9 ± 13.5 mm(3)) was significantly smaller than that in vehicle rats (114.9 ± 15.3 mm(3), p < 0.01). D-allose treatment significantly suppressed the MPO activity and the number of MPO-positive cells compared with those in the vehicle group, suggesting that treatment with D-allose can reduce the infiltration of leukocytes into the ischemic tissue. Treatment of D-allose also significantly decreased the number of COX-2-positive cells and microglial activation in the ischemic tissue. The present results demonstrate that D-allose exerts potent neuroprotective effects against acute cerebral I/R injury, and constitute the first evidence of anti-inflammatory effects of D-allose which considerably contributes to the beneficial effects. Treatment with D-allose might provide a new strategy and clinically beneficial outcome for acute ischemic stroke.

Perinatal asphyxia: CNS development and deficits with delayed onset

Perinatal asphyxia constitutes a prototype of obstetric complications occurring when pulmonary oxygenation is delayed or interrupted. The primary insult relates to the duration of the period lacking oxygenation, leading to death if not re-established. Re-oxygenation leads to a secondary insult, related to a cascade of biochemical events required for restoring proper function. Perinatal asphyxia interferes with neonatal development, resulting in long-term deficits associated to mental and neurological diseases with delayed clinical onset, by mechanisms not yet clarified. In the experimental scenario, the effects observed long after perinatal asphyxia have been explained by overexpression of sentinel proteins, such as poly(ADP-ribose) polymerase-1 (PARP-1), competing for NAD⁺ during re-oxygenation, leading to the idea that sentinel protein inhibition constitutes a suitable therapeutic strategy. Asphyxia induces transcriptional activation of pro-inflammatory factors, in tandem with PARP-1 overactivation, and pharmacologically induced PARP-1 inhibition also down-regulates the expression of proinflammatory cytokines. Nicotinamide has been proposed as a suitable PARP-1 inhibitor. Its effect has been studied in an experimental model of global hypoxia in rats. In that model, the insult is induced by immersing rat fetus into a water bath for various periods of time. Following asphyxia, the pups are delivered, treated, and nursed by surrogate dams, pending further experiments. Nicotinamide rapidly distributes into the brain following systemic administration, reaching steady state concentrations sufficient to inhibit PARP-1 activity for several hours, preventing several of the long-term consequences of perinatal asphyxia, supporting the idea that nicotinamide constitutes a lead for exploring compounds with similar or better pharmacological profiles.

Potential roles of HDAC inhibitors in mitigating ischemia-induced brain damage and facilitating endogenous regeneration and recovery

Ischemic stroke is a leading cause of death and disability worldwide, with few available treatment options. The pathophysiology of cerebral ischemia involves both early phase tissue damage, characterized by neuronal death, inflammation, and blood-brain barrier breakdown, followed by late phase neurovascular recovery. It is becoming clear that any promising treatment strategy must target multiple points in the evolution of ischemic injury to provide substantial therapeutic benefit. Histone deacetylase (HDAC) inhibitors are a class of drugs that increase the acetylation of histone and non-histone proteins to activate transcription, enhance gene expression, and modify the function of target proteins. Acetylation homeostasis is often disrupted in neurological conditions, and accumulating evidence suggests that HDAC inhibitors have robust protective properties in many preclinical models of these disorders, including ischemic stroke. Specifically, HDAC inhibitors such as trichostatin A, valproic acid, sodium butyrate, sodium 4-phenylbutyrate, and suberoylanilide hydroxamic acid have been shown to provide robust protection against excitotoxicity, oxidative stress, ER stress, apoptosis, inflammation, and bloodbrain barrier breakdown. Concurrently, these agents can also promote angiogenesis, neurogenesis and stem cell migration to dramatically reduce infarct volume and improve functional recovery after experimental cerebral ischemia. In the following review, we discuss the mechanisms by which HDAC inhibitors exert these protective effects and provide evidence for their strong potential to ultimately improve stroke outcome in patients.

Novel therapeutic strategies for traumatic brain injury: acute antioxidant reinforcement

Traumatic brain injury (TBI) is the most important cause of disability in individuals under the age of 45 years and thus represents a significant social and economic burden. Evidence strongly suggests that oxidative stress is a cornerstone event leading to and propagating secondary injury mechanisms such as excitotoxicity, mitochondrial dysfunction, apoptosis, autophagy, brain edema, and inflammation. TBI has defied conventional approaches to diagnosis and therapy development because of its heterogeneity and complexity. Therefore, it is necessary to explore alternative approaches to therapy development for TBI. The aim of this review is to present a therapeutic approach for TBI, taking into account the evidence supporting the role for oxidative stress in the pathophysiological processes of secondary brain injury. The role of agents such as mitochondria-targeted antioxidants (melatonin and new mitochondria-targeted antioxidants), nicotinamide adenine dinucleotide phosphate (NADPH) inhibitors (antioxidant vitamins and apocynin), and other compounds having mainly antioxidant properties (hydrogen-rich saline, sulforaphane, U-83836E, omega-3, and polyphenols) is covered. The rationale for innovative antioxidant therapies based on current knowledge and particularly the most recent studies regarding this field is discussed. Particular considerations and translational potential of new TBI treatments are examined and a novel therapeutic proposal for TBI is presented.

Temporal determination of lung NO system and COX-2 upregulation following ischemia-reperfusion injury

BACKGROUND

Pulmonary ischemia-reperfusion (IR) is a biopathological event detectable in several clinical conditions, including lung transplantation, cardiopulmonary bypass, resuscitation, and pulmonary embolism. The understanding behind the activation of various inflammatory mediators regulating the apoptotic pathways remains largely unknown. We investigated the temporal expression of endothelial nitric oxide (eNOS), inducible (iNOS), and cyclooxygenase-2 (COX-2) proteins following lung-IR injury.

METHODS

Lung IR was induced in anesthetized rats. One hour ischemia was performed by clamping the left hilum. eNOS, iNOS, and COX-2 levels in the bronchoalveolar lavage (BAL) were measured at different time points after restoring lung perfusion in conjunction with histological changes and cellular apoptosis.

RESULTS

BAL-eNOS levels were increased as early as 3 hours post IR, attaining the highest values (5.5 U/mL) at 3 hours, compared to non-IR values (2.8 U/mL). BAL-iNOS increased at 3-hour post-IR (3 U/mL). iNOS reached the highest levels at 24 hours (4.5 U/mL) as compared to nonischemic lungs (1.8 U/mL). COX-2 peaked at 12 hours (.025 U/mL) compared to 3, 24, and 48 hours. Highest apoptotic rates were detected at 12 and 48 hours following IR.

CONCLUSIONS

The time-associated involvement of eNOS, iNOS, and COX-2 enzymes during the evolution of IR injury may point to an early reaction of the NOSs system versus the COX-2. Similar patterns of enzymatic activity were previously shown in the context of lung IR injury. This temporal activation may indicate an involvement of eNOS in an early reparative response, and possibly the late-pathological response, mediated by the coinduction of iNOS-COX-2.

Antistress effect of red ginseng in brain cells is mediated by TACE repression via PADI4

Ginseng is known to have antistress effects. Previously, red ginseng (RG) was shown to repress stress-induced peptidyl arginine deiminase type IV (PADI4) via estrogen receptor β (ERβ) in the brain, thus inhibiting brain cell apoptosis. Moreover, tumor necrosis factor (TNF)-α plays a critical role in immobilization (IMO) stress. However, the signaling pathway of RG-mediated repressesion of inflammation is not completely understood. In this study, we determined how RG modulated gene expression in stressed brain cells. Since secretion of TNF-α is modulated via TNF-α converting enzyme (TACE) and nuclear factor (NF)-κB, we examined the inflammatory pathway in stressed brain cells. Immunohistochemistry revealed that TACE was induced by IMO stress, but RG repressed TACE induction. Moreover, PADI4 siRNA repressed TACE expression compared to the mock transfected control suggesting that PADI4 was required for TACE expression. A reporter assay also revealed that H2O2 oxidative stress induced NF-κB in neuroblastoma SK-N-SH cells, however, RG pretreatment repressed NF-κB induction. These findings were supported by significant induction of nitric oxide and reactive oxygen species (ROS) by oxidative stress, which could be repressed by RG administration. Taken together, RG appeared to repress stress-induced PADI4 via TACE and NF-κB in brain cells thus preventing production of ROS and subsequently protecting brain cells from apoptosis.

Neuroprotective Effects of a Butanol Fraction of Rosa hybrida Petals in a Middle Cerebral Artery Occlusion Model

The neuroprotective effects of a butanol fraction of white rose petal extract (WRPE-BF) were investigated in a middle cerebral artery occlusion (MCAO) model. Seven week-old male rats were orally administered WRPE-BF for 2 weeks and subjected to MCAO for 2 h, followed by reperfusion. Twenty-four h later, MCAO-induced behavioral dysfunctions were markedly improved in a dose-dependent manner by pretreatment with WRPE-BF. Moreover, higher dose of WRPE-BF not only decreased infarction area but also effectively reduced astrogliosis. The expression of inducible nitric oxide synthase, cyclooxygenase-2, and glial fibrillary acidic protein in MCAO model were markedly inhibited by WRPE-BF treatment. Notably, WRPE-BF decreased nitric oxide and malondialdehyde levels in the striatum and subventricular zone of stroke-challenged brains. These data suggested that WRPE-BF may exert its neuroprotective effects via anti-oxidative and anti-inflammatory activities against ischemia-reperfusion brain injury and could be a good candidate as a therapeutic target for ischemic stroke.

Traditional Chinese medicine for the treatment of primary dysmenorrhea: how do Yuanhu painkillers effectively treat dysmenorrhea?

AIM

To examine the efficacy of YuanHu painkillers (YHP) as a treatment for primary dysmenorrhea and to reveal YHP's principle formula.

METHODS

A Wistar rat uterine contraction model was utilized in this study. Rats were given 0.698g/kg YHP, 0.07g/kg tetrahydropalmatine (THP; YHP's main component), 0.02g/kg imperatorin (IMP), or THP+IMP (0.07+0.02g/kg) as polypharmacy (PG) by gavage. H&E staining and histopathological examination of the uteri tissue samples were performed. We then detected superoxide dismutase (SOD) and malondialdehyde (MDA), nitric oxide (NO), as well as inducible nitric oxide synthase (iNOS), i-κB, nuclear factor-κB (NF-κB), and cyclooxygenase-2 (COX-2) indices.

RESULTS

PG significantly inhibited the uterine contraction of the primary dysmenorrhea rat model (p<0.05), and was significantly different than single-agent therapy (p<0.05). Histopathological examination showed inflammation in the uteri of the control group which YHP and its main constitutes alleviated. THP significantly inhibited the contraction of isolated uteri caused by Ach, PGF2α and oxytocin in a concentration-dependent fashion. THP and IMP both significantly affected the levels of NO, activation of NF-κB, up-regulated the expression of i-κB and down-regulated the expression of both iNOS and COX-2. IMP obviously decreased the level of MDA and increased the activation of SOD (p<0.05). PG obviously improved all the parameters mentioned above (p<0.05).

CONCLUSIONS

YHP exerted protective effects on primary dysmenorrhea in rats and remarkably alleviated the severity of experimental primary dysmenorrhea. The combined strategy proved to be more effective than either THP or IMP alone and may have synergistic effects in combination in primary dysmenorrhea. Mechanisms that might account for the beneficial effects include abating oxidative stress, inhibiting over-inflammatory reaction, and alleviating the contraction of isolated rat uteri by inhibiting the influx of extracellular Ca(2+). Broad potential for future clinical practice is foreseeable.

Anti-oxidative stress effect of red ginseng in the brain is mediated by peptidyl arginine deiminase type IV (PADI4) repression via estrogen receptor (ER) β up-regulation

AIM OF THE STUDY

Ginseng has been used as an anti-stress agent, and its active ingredient, ginsenoside, is similar in structure to estrogen. However, the effect of ginseng on the stressed brain is not completely understood. The aim of this study is to understand systematically how red ginseng (RG) affects gene expressions in the brain of immobilization (IMO) stressed mice to elucidate its underlying mechanism.

MATERIALS AND METHODS

For in vivo experiments, mice were stressed by immobilization for 30, 45, or 60 min, and gene expression in the mice brain was analyzed by microarray and system biology. Apoptosis was measured by terminal deoxynucleotidyl transferase-mediated digoxigenin-dUTP nick-end labeling (TUNEL) staining, and gene expression by Western blot or qPCR. For in vitro study, the SK-N-SH neuroblastoma cells were stressed by H2O2 exposure. The resultant cytotoxicity was measured by MTT assay, and gene expression by Western blot, ELISA, or qPCR.

RESULTS

Microarray analysis of genes in IMO stressed mice brains showed that RG administration prior to IMO stress downregulated >40 genes including peptidyl arginine deiminase type 4 (PADI4). Interestingly, PADI4 was up-regulated by various stresses such as H2O2, acrylamide, and tunicamycin in neuroblastoma SK-N-SH cells but inhibited by RG. IMO stress and in vitro H2O2 stress depressed the estrogen receptor (ER)-β expression but not ERα. However, RG treatment increased ERβ expression both in vivo and in vitro. Comparative analysis regarding the networks by systems biology revealed that TNF-α plays a critical role in IMO stress, and the cell death associated network was much higher than other categories. Consistently, the IMO stress induced TNF-α and Cox-2 expressions, malondialdehyde (MDA), and cell death in the brain, whereas RG administration inhibited these inductions in vivo. siRNA and transient expression studies revealed that ERβ inhibited the PADI4 expression.

CONCLUSION

PADI4 could be used as an oxidative stress marker. RG seems to inhibit oxidative stress-inducible PADI4 by up-regulating ERβ expression in the brain thus protecting brain cells from apoptosis.

Xanthotoxol exerts neuroprotective effects via suppression of the inflammatory response in a rat model of focal cerebral ischemia

We previously found that xanthotoxol, one of the major active ingredients in Cnidium monnieri (L.) Cusson, exerts protective effects in a rat model of focal cerebral ischemia/reperfusion injury by alleviating brain edema, inhibiting the neutrophil infiltration, and decreasing the expression of intercellular adhesion molecule-1 (ICAM-1) and E-selectin. The present study was designed to further determine the possible mechanisms of action of neuroprotective properties of xanthotoxol after cerebral ischemia. Transient focal cerebral ischemia/reperfusion model in male Sprague-Dawley rats was induced by 2-h middle cerebral artery occlusion followed by 24-h reperfusion. Xanthotoxol (5 and 10 mg/kg) or vehicle were administered intraperitoneally at 1 and 12 h after the onset of ischemia. At 24 h after reperfusion, we assessed the effect of xanthotoxol on the blood-brain barrier (BBB) permeability, the production of pro-inflammatory mediators such as interleukin (IL)-1β, tumor necrosis factor (TNF)-α, IL-8, nitric oxide (NO), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and the p65 subunit of the transcription factor, nuclear factor-κB (NF-κB) in the cortex after ischemic insult. The results showed that xanthotoxol treatment significantly attenuated BBB disruption, reduced the IL-1β, TNF-α, IL-8 and NO level, and attenuated the iNOS activity compared with vehicle-treated animals. Further, xanthotoxol treatment also significantly prevented the ischemia/reperfusion-induced increase in the protein expression of iNOS, COX-2, and the nuclear NF-κB p65. These results, taken together with those of our previous study, suggest that the neuroprotection may be attributed to the ability of xanthotoxol to attenuate the expression of pro-inflammatory mediators and thereby inhibit the inflammatory response after cerebral ischemia.