Brain Ischemic Tolerance Triggered by Preconditioning Involves Modulation of Tumor Necrosis Factor-α-Stimulated Gene 6 (TSG-6) in Mice Subjected to Transient Middle Cerebral Artery Occlusion.

Ischemic preconditioning (PC) induced by a sub-lethal cerebral insult triggers brain tolerance against a subsequent severe injury through diverse mechanisms, including the modulation of the immune system. Tumor necrosis factor (TNF)-α-stimulated gene 6 (TSG-6), a hyaluronate (HA)-binding protein, has recently been involved in the regulation of the neuroimmune response following ischemic stroke. Thus, we aimed at assessing whether the neuroprotective effects of ischemic PC involve the modulation of TSG-6 in a murine model of transient middle cerebral artery occlusion (MCAo).

Characterization of the Involvement of Tumour Necrosis Factor (TNF)-α-Stimulated Gene 6 (TSG-6) in Ischemic Brain Injury Caused by Middle Cerebral Artery Occlusion in Mouse.

The identification of novel targets to modulate the immune response triggered by cerebral ischemia is crucial to promote the development of effective stroke therapeutics. Since tumour necrosis factor (TNF)-α-stimulated gene 6 (TSG-6), a hyaluronate (HA)-binding protein, is involved in the regulation of immune and stromal cell functions in acute neurodegeneration, we aimed to characterize its involvement in ischemic stroke. Transient middle cerebral artery occlusion (1 h MCAo, followed by 6 to 48 of reperfusion) in mice resulted in a significant elevation in cerebral TSG-6 protein levels, mainly localized in neurons and myeloid cells of the lesioned hemisphere.

Harmonization of sensorimotor deficit assessment in a registered multicentre pre-clinical randomized controlled trial using two models of ischemic stroke.

Multicentre preclinical randomized controlled trials (pRCTs) are a valuable tool to improve experimental stroke research, but are challenging and therefore underused. A common challenge regards the standardization of procedures across centres. We here present the harmonization phase for the quantification of sensorimotor deficits by composite neuroscore, which was the primary outcome of two multicentre pRCTs assessing remote ischemic conditioning in rodent models of ischemic stroke.

Tumor Necrosis Factor (TNF)-α-Stimulated Gene 6 (TSG-6): A Promising Immunomodulatory Target in Acute Neurodegenerative Diseases.

Tumor necrosis factor (TNF)-α-stimulated gene 6 (TSG-6), the first soluble chemokine-binding protein to be identified in mammals, inhibits chemotaxis and transendothelial migration of neutrophils and attenuates the inflammatory response of dendritic cells, macrophages, monocytes, and T cells. This immunoregulatory protein is a pivotal mediator of the therapeutic efficacy of mesenchymal stem/stromal cells (MSC) in diverse pathological conditions, including neuroinflammation. However, TSG-6 is also constitutively expressed in some tissues, such as the brain and spinal cord, and is generally upregulated in response to inflammation in monocytes/macrophages, dendritic cells, astrocytes, vascular smooth muscle cells and fibroblasts.

Encapsulation of Alpha-Lipoic Acid in Functional Hybrid Liposomes: Promising Tool for the Reduction of Cisplatin-Induced Ototoxicity.

In this study, in order to address the drawback of cisplatin (CDDP)-induced ototoxicity, we propose a straightforward strategy based on the delivery of a sulfur-based antioxidant, such as lipoic acid (LA), to HEI-OC1 cells. To this aim, hybrid liposomes (LA@PCGC) with a spherical shape and a mean diameter of 25 nm were obtained by direct sonication of LA, phosphatidylcholine and a gelatin-curcumin conjugate in a physiological buffer. LA@PCGC were found to be stable over time, were quickly (i.

Ischemic Preconditioning Modulates the Peripheral Innate Immune System to Promote Anti-Inflammatory and Protective Responses in Mice Subjected to Focal Cerebral Ischemia.

The development of tolerance triggered by a sublethal ischemic episode (preconditioning, PC) involves a complex crosstalk between neurons, astrocytes and microglia, although the role of the peripheral immune system in this context is largely unexplored. Here, we report that severe cerebral ischemia caused by transient middle cerebral artery occlusion (MCAo) in adult male mice elevates blood counts of inflammatory neutrophils and monocytes, and plasma levels of miRNA-329-5p. These inflammatory responses are prevented by ischemic PC induced by 15 min MCAo, 72h before the severe insult (1h MCAo).

Plasma Membrane and Organellar Targets of STIM1 for Intracellular Calcium Handling in Health and Neurodegenerative Diseases.

Located at the level of the endoplasmic reticulum (ER) membrane, stromal interacting molecule 1 (STIM1) undergoes a complex conformational rearrangement after depletion of ER luminal Ca. Then, STIM1 translocates into discrete ER-plasma membrane (PM) junctions where it directly interacts with and activates plasma membrane Orai1 channels to refill ER with Ca. Furthermore, Ca entry due to Orai1/STIM1 interaction may induce canonical transient receptor potential channel 1 (TRPC1) translocation to the plasma membrane, where it is activated by STIM1.

CD163 as a Potential Biomarker of Monocyte Activation in Ischemic Stroke Patients.

In ischemic stroke patients, a higher monocyte count is associated with disease severity and worse prognosis. The complex correlation between subset phenotypes and functions underscores the importance of clarifying the role of monocyte subpopulations. We examined the subtype-specific distribution of the CD163+ and CD80+ circulating monocytes and evaluated their association with the inflammatory status in 26 ischemic stroke patients and 16 healthy controls.

Combining Dextran Conjugates with Stimuli-Responsive and Folate-Targeting Activity: A New Class of Multifunctional Nanoparticles for Cancer Therapy.

Nanoparticles with active-targeting and stimuli-responsive behavior are a promising class of engineered materials able to recognize the site of cancer disease, targeting the drug release and limiting side effects in the healthy organs. In this work, new dual pH/redox-responsive nanoparticles with affinity for folate receptors were prepared by the combination of two amphiphilic dextran (DEX) derivatives. DEXFA conjugate was obtained by covalent coupling of the polysaccharide with folic acid (FA), whereas DEXssPEGCOOH derived from a reductive amination step of DEX was followed by condensation with polyethylene glycol 600.

Systemic administration of sunflower oil exerts neuroprotection in a mouse model of transient focal cerebral ischaemia.

Objectives: Natural products are valuable sources of nutraceuticals for the prevention or treatment of ischemic stroke, a major cause of death and severe disability worldwide. Among the mechanisms implicated in cerebral ischemia-reperfusion damage, oxidative stress exerts a pivotal role in disease progression. Given the high antioxidant potential of most components of sunflower oil, we have explored its effects on ischemic brain injury produced in the mouse by transient occlusion of the middle cerebral artery (MCAo).

Multicentre translational Trial of Remote Ischaemic Conditioning in Acute Ischaemic Stroke (TRICS): protocol of multicentre, parallel group, randomised, preclinical trial in female and male rat and mouse from the Italian Stroke Organization (ISO) Basic Science network.

Introduction: Multicentre preclinical randomised controlled trials (pRCT) are emerging as a necessary step to confirm efficacy and improve translation into the clinic. The aim of this project is to perform two multicentre pRCTs (one in rats and one in mice) to investigate the efficacy of remote ischaemic conditioning (RIC) in an experimental model of severe ischaemic stroke.

Methods And Analysis: Seven research laboratories within the Italian Stroke Organization (ISO) Basic Science network will participate in the study.

Characterization of CB2 Receptor Expression in Peripheral Blood Monocytes of Acute Ischemic Stroke Patients.

Both preclinical and clinical evidence supports the involvement of the endocannabinoid system in the pathobiology of cerebral ischemia. Selective cannabinoid-2 (CB2) receptor agonists exert significant neuroprotection in animal models of focal brain ischemia through a robust anti-inflammatory effect, involving both resident and peripheral immune cells. Nevertheless, no definitive studies demonstrating the relevance of CB2 receptors in human stroke exist.

Modulation of Cerebral Store-operated Calcium Entry-regulatory Factor (SARAF) and Peripheral Orai1 Following Focal Cerebral Ischemia and Preconditioning in Mice.

Store-operated Ca entry (SOCE) contributes to Ca refilling of endoplasmic reticulum (ER), but also provides Ca influx involved in physiological and pathological signalling functions. Upon depletion of Ca store, the sensor protein stromal interaction molecule (STIM) activates Orai1, forming an ion-conducting pore highly selective for Ca. SOCE-associated regulatory factor (SARAF) associates with STIM1 to facilitate a slow form of Ca-dependent inactivation of SOCE or interacts with Orai1 to stimulate SOCE in STIM1-independent manner.

Azithromycin Affords Neuroprotection in Rat Undergone Transient Focal Cerebral Ischemia.

Repurposing existing drugs represents a promising approach for successful development of acute stroke therapies. In this context, the macrolide antibiotic azithromycin has been shown to exert neuroprotection in mice due to its immunomodulatory properties. Here, we have demonstrated that acute administration of a single dose of azithromycin upon reperfusion produces a dose-dependent (ED = 1.

Self-assembling Dextran prodrug for redox- and pH-responsive co-delivery of therapeutics in cancer cells.

Self-assembling prodrug containing pH- and redox-responsive functional groups was prepared by covalent conjugation of Doxorubicin (Dox) and lipoic acid (LA) to a polyaldehyde Dextran (PAD). The resultant amphiphilic DoxPADLA forms, in a single step, hemocompatible vesicular systems able to respond to intracellular signals without using external crosslinking agents. Camptothecin (CPT) was encapsulated exploiting the hydrophobic interactions with the vesicle membrane, and release experiments, carried out in media mimicking the physiological and endolysosomial compartments, in the absence or presence of Glutathione, proved the ability of the system to modulate drug release in relation to the variation of pH and redox potential.

Facile synthesis of pH-responsive polymersomes based on lipidized PEG for intracellular co-delivery of curcumin and methotrexate.

pH-responsive polymersomes were obtained by self-assembling of a carboxyl-terminated PEG amphiphile achieved via esterification of PEG diacid with PEG40stearate. The obtained vesicular systems had spherical shape and a mean diameter of 70 nm. The pH sensitivity was assessed by measuring the variations of particles mean diameter after incubation in media mimicking the physiological (pH 7.

Paradigm Shift to Neuroimmunomodulation for Translational Neuroprotection in Stroke.

The treatment of acute ischemic stroke is still an unresolved clinical problem since the only approved therapeutic intervention relies on early blood flow restoration through pharmacological thrombolysis, mechanical thrombus removal, or a combination of both strategies. Due to their numerous complications and to the narrow time-window for the intervention, only a minority of stroke patients can actually benefit from revascularization procedures, highlighting the urgent need of identifying novel strategies to prevent the progression of an irreversible damage in the ischemic penumbra. During the past three decades, the attempts to target the pathways implicated in the ischemic cascade (e.

On the Role of Store-Operated Calcium Entry in Acute and Chronic Neurodegenerative Diseases.

In both excitable and non-excitable cells, calcium (Ca) signals are maintained by a highly integrated process involving store-operated Ca entry (SOCE), namely the opening of plasma membrane (PM) Ca channels following the release of Ca from intracellular stores. Upon depletion of Ca store, the stromal interaction molecule (STIM) senses Ca level reduction and migrates from endoplasmic reticulum (ER)-like sites to the PM where it activates the channel proteins Orai and/or the transient receptor potential channels (TRPC) prompting Ca refilling. Accumulating evidence suggests that SOCE dysregulation may trigger perturbation of intracellular Ca signaling in neurons, glia or hematopoietic cells, thus participating to the pathogenesis of diverse neurodegenerative diseases.

Post-ischemic treatment with azithromycin protects ganglion cells against retinal ischemia/reperfusion injury in the rat.

Purpose: Retinal ischemic phenomena occur in several ocular diseases that share the degeneration and death of retinal ganglion cells (RGCs) as the final event. We tested the neuroprotective effect of azithromycin, a widely used semisynthetic macrolide antibiotic endowed with anti-inflammatory and immunomodulatory properties, in a model of retinal ischemic injury induced by transient elevation of intraocular pressure in the rat.

Methods: Retinal ischemia was induced in adult rats with transient elevation of intraocular pressure.

Anticholinergic burden and 1-year mortality among older patients discharged from acute care hospital.

Aim: The association between anticholinergic burden and mortality is controversial. We aimed to investigate whether the anticholinergic cognitive burden (ACB) score predicts 1-year mortality in older patients discharged from acute care hospitals.

Methods: Our series consisted of 807 hospitalized patients aged ≥65 years.

Excitatory and inhibitory amino acid neurotransmitters in stroke: from neurotoxicity to ischemic tolerance.

The search for neuroprotection in acute ischemic stroke has been dramatically disappointing, with virtually all clinical trials failed for excessive toxicity or lack of efficacy of the tested drug; whereby, current treatments are exclusively based on reperfusion. Given the crucial role of amino acid neurotransmission in ischemic pathobiology, numerous failed strategies were aimed at blocking ionotropic glutamate receptor-mediated excitotoxicity or potentiating GABA-mediated inhibition. Recent work has revived the interest of pharmacologists toward glutamate and GABA receptors, due to a better understanding of subtype-specific toxicity and their involvement in ischemic tolerance.

Endothelial nitric oxide synthase inhibition triggers inflammatory responses in the brain of male rats exposed to ischemia-reperfusion injury.

Nitric oxide (NO) derived from endothelial NO synthase (eNOS) plays a role in preserving and maintaining the brain's microcirculation, inhibiting platelet aggregation, leukocyte adhesion, and migration. Inhibition of eNOS activity results in exacerbation of neuronal injury after ischemia by triggering diverse cellular mechanisms, including inflammatory responses. To examine the relative contribution of eNOS in stroke-induced neuroinflammation, we analyzed the effects of systemic treatment with l-N-(1-iminoethyl)ornithine (L-NIO), a relatively selective eNOS inhibitor, on the expression of MiR-155-5p, a key mediator of innate immunity regulation and endothelial dysfunction, in the cortex of male rats subjected to transient middle cerebral artery occlusion (tMCAo) followed by 24 hr of reperfusion.

Modulation of cerebral RAGE expression following nitric oxide synthase inhibition in rats subjected to focal cerebral ischemia.

The receptor for advanced glycation endproducts (RAGE) is a key mediator of neuroinflammation following cerebral ischemia. Nitric oxide (NO) plays a dualistic role in cerebral ischemia, depending on whether it originates from neuronal, inducible or endothelial synthase. Although a dynamic interplay between RAGE and NO pathways exists, its relevance in ischemic stroke has not been investigated.

Poly(ADP-ribose) polymerase is not involved in the neuroprotection exerted by azithromycin against ischemic stroke in mice.

Repurposing azithromycin has recently emerged as a promising strategy for the acute treatment of ischemic stroke. The mechanism of neuroprotection depends on the ability of this macrolide to promote polarization of microglia/macrophages towards beneficial M2 phenotypes. The immunomodulatory and anti-inflammatory effects of azithromycin, well documented in chronic inflammatory airway diseases, have been ascribed to the inhibition of the transcription factors nuclear factor (NF)-κB and activator protein (AP)-1.

Neuroprotective Properties of a Macrolide Antibiotic in a Mouse Model of Middle Cerebral Artery Occlusion: Characterization of the Immunomodulatory Effects and Validation of the Efficacy of Intravenous Administration.

Repurposing the macrolide antibiotic azithromycin has recently been suggested as a promising neuroprotective strategy for the acute treatment of ischemic stroke. Here, we aim at further characterizing the immunomodulatory properties of intraperitoneal (i.p.