Systemic administration of blood-derived exosomes induced by remote ischemic post-conditioning, by delivering a specific cluster of miRNAs, ameliorates ischemic damage and neurological function.

MicroRNAs, contained in exosomes or freely circulating in the plasma, might play a pivotal role in the infarct-sparing effect exerted by emote limb ischemic postconditioning (RLIP). The aims of the present study were: (1) To evaluate the effect of pure exosomes isolated from plasma of animals subjected to RLIP systemically administered to ischemic rats; (2) To finely dissect exosomes content in terms of miRNAs; (3) To select those regulatory miRNAs specifically expressed in protective exosomes and to identify molecular pathways involved in their neurobeneficial effects. Circulating exosomes were isolated from blood of animals exposed to RLIP and administered to animals exposed to tMCAO by intracerebroventricular, intraperitoneal or intranasal routes.

Newly Synthesized Indolylacetic Derivatives Reduce Tumor Necrosis Factor-Mediated Neuroinflammation and Prolong Survival in Amyotrophic Lateral Sclerosis Mice.

The debilitating neurodegenerative disease known as amyotrophic lateral sclerosis (ALS) is characterized by the progressive loss of motor neurons (MNs) in the brain, spinal cord, and motor cortex. The ALS neuroinflammatory component is being characterized and includes the overexpression of mediators, such as inducible nitric oxide synthase (iNOS) and tumor necrosis factor-α (TNF-α). Currently, there are no effective treatments for ALS.

Stroke Causes DNA Methylation at Heart Promoter in the Brain Via DNMT1/MeCP2/REST Epigenetic Complex.

Background: REST (Repressor-Element 1 [RE1]-silencing transcription factor) inhibits Na/Caexchanger-1 () transcription in neurons through the binding of RE1 site on brain promoter after stroke. We identified a new putative RE1 site in heart promoter sequence (-RE1) that participates in neuronal transcription. Because REST recruits DNA-methyltransferase-1 (DNMT1) and MeCP2 (methyl-CpG binding protein 2) on different neuronal genes, we investigated the role of this complex in transcriptional regulation after stroke.

Anti-miRNA103/107 encapsulated in transferrin-conjugated lipid nanoparticles crosses blood-brain barrier and reduces brain ischemic damage.

MicroRNA (miRNA), by post-transcriptionally regulating the expression of genes involved in stroke response, represents important effectors in stroke pathophysiology. Recently, the 103/107 miRNA family emerged as a possible therapeutic target in stroke, as it controls the expression of sodium calcium exchanger 1, a plasma membrane transporter that plays a fundamental role in stroke pathophysiology. Although the neuroprotective properties of this and other miRNAs are promising, several pharmacokinetic drawbacks remain to be faced for the development of a translatable therapy based on small RNAs in CNS diseases.

Metabolic rewiring and autophagy inhibition correct lysosomal storage disease in mucopolysaccharidosis IIIB.

Mucopolysaccharidoses (MPSs) are lysosomal disorders with neurological involvement for which no cure exists. Here, we show that recombinant NK1 fragment of hepatocyte growth factor rescues substrate accumulation and lysosomal defects in MPS I, IIIA and IIIB patient fibroblasts. We investigated PI3K/Akt pathway, which is of crucial importance for neuronal function and survival, and demonstrate that PI3K inhibition abolishes NK1 therapeutic effects.

Chronic exposure to l-BMAA cyanotoxin induces cytoplasmic TDP-43 accumulation and glial activation, reproducing an amyotrophic lateral sclerosis-like phenotype in mice.

Background: Amyotrophic lateral sclerosis (ALS) is a progressive and often fatal neurodegenerative disease characterized by the loss of Motor Neurons (MNs) in spinal cord, motor cortex and brainstem. Despite significant efforts in the field, the exact pathogenetic mechanisms underlying both familial and sporadic forms of ALS have not been fully elucidated, and the therapeutic possibilities are still very limited. Here we investigate the molecular mechanisms of neurodegeneration induced by chronic exposure to the environmental cyanotoxin L-BMAA, which causes a form of ALS/Parkinson's disease (PD) in several populations consuming food and/or water containing high amounts of this compound.

Stroke by inducing HDAC9-dependent deacetylation of HIF-1 and Sp1, promotes TfR1 transcription and GPX4 reduction, thus determining ferroptotic neuronal death.

The inhibition of histone deacetylase 9 (HDAC9) represents a promising druggable target for stroke intervention. Indeed, HDAC9 is overexpressed in neurons after brain ischemia where exerts a neurodetrimental role. However, mechanisms of HDAC9-dependent neuronal cell death are not yet well established.

GATA3 (GATA-Binding Protein 3)/KMT2A (Lysine-Methyltransferase-2A) Complex by Increasing H3K4-3me (Trimethylated Lysine-4 of Histone-3) Upregulates NCX3 (Na-Ca Exchanger 3) Transcription and Contributes to Ischemic Preconditioning Neuroprotection.

Background And Purpose: NCX3 (Na+-Ca2+ exchanger 3) plays a relevant role in stroke; indeed its pharmacological blockade or its genetic ablation exacerbates brain ischemic damage, whereas its upregulation takes part in the neuroprotection elicited by ischemic preconditioning. To identify an effective strategy to induce an overexpression of NCX3, we examined transcription factors and epigenetic mechanisms potentially involved in NCX3 gene regulation.

Methods: Brain ischemia and ischemic preconditioning were induced in vitro by exposure of cortical neurons to oxygen and glucose deprivation plus reoxygenation (OGD/Reoxy) and in vivo by transient middle cerebral artery occlusion.

Prolonged NCX activation prevents SOD1 accumulation, reduces neuroinflammation, ameliorates motor behavior and prolongs survival in a ALS mouse model.

Imbalance in cellular ionic homeostasis is a hallmark of several neurodegenerative diseases including Amyotrophic Lateral Sclerosis (ALS). Sodium-calcium exchanger (NCX) is a membrane antiporter that, operating in a bidirectional way, couples the exchange of Ca and Na  ions in neurons and glial cells, thus controlling the intracellular homeostasis of these ions. Among the three NCX genes, NCX1 and NCX2 are widely expressed within the CNS, while NCX3 is present only in skeletal muscles and at lower levels of expression in selected brain regions.

Remote postconditioning ameliorates stroke damage by preventing let-7a and miR-143 up-regulation.

Remote limb ischemic postconditioning (RLIP) is a well-established neuroprotective strategy able to protect the brain from a previous harmful ischemic insult through a sub-lethal occlusion of the femoral artery. Neural and humoral mechanisms have been proposed as mediators required to transmit the peripheral signal from limb to brain. Moreover, different studies suggest that protection observed at brain level is associated to a general genetic reprogramming involving also microRNAs (miRNAs) intervention.

Sumoylation of sodium/calcium exchanger in brain ischemia and ischemic preconditioning.

The small ubiquitin-like modifier (SUMO) conjugation (or SUMOylation) is a post-translational protein modification mechanism activated by different stress conditions that has been recently investigated in experimental models of cerebral ischemia. The expression of SUMOylation enzymes and substrates is not restricted to the nucleus, since they are present also in the cytoplasm and on plasma membrane and are involved in several physiological and pathological conditions. In the last decades, convincing evidence have supported the idea that the increased levels of SUMOylated proteins may induce tolerance to ischemic stress.

miR-206 Reduces the Severity of Motor Neuron Degeneration in the Facial Nuclei of the Brainstem in a Mouse Model of SMA.

Spinal muscular atrophy (SMA) is a severe neuromuscular disease affecting infants caused by alterations of the survival motor neuron gene, which results in progressive degeneration of motor neurons (MNs). Although an effective treatment for SMA patients has been recently developed, the molecular pathway involved in selective MN degeneration has not been yet elucidated. In particular, miR-206 has been demonstrated to play a relevant role in the regeneration of neuromuscular junction in several MN diseases, and particularly it is upregulated in the quadriceps, tibialis anterior, spinal cord, and serum of SMA mice.

Genetic Up-Regulation or Pharmacological Activation of the Na/Ca Exchanger 1 (NCX1) Enhances Hippocampal-Dependent Contextual and Spatial Learning and Memory.

The Na/Ca exchanger 1 (NCX1) participates in the maintenance of neuronal Na and Ca homeostasis, and it is highly expressed at synapse level of some brain areas involved in learning and memory processes, including the hippocampus, cortex, and amygdala. Furthermore, NCX1 increases Akt1 phosphorylation and enhances glutamate-mediated Ca influx during depolarization in hippocampal and cortical neurons, two processes involved in learning and memory mechanisms. We investigated whether the modulation of NCX1 expression/activity might influence learning and memory processes.

Anti-miR-223-5p Ameliorates Ischemic Damage and Improves Neurological Function by Preventing NCKX2 Downregulation after Ischemia in Rats.

It has been demonstrated that the K-dependent Na/Ca exchanger, NCKX2, is a new promising stroke neuroprotective target. However, because no pharmacological activator of NCKX2 is still available, microRNA (miRNA) may represent an alternative method to modulate NCKX2 expression. In particular, by bioinformatics analysis, miR-223-5p emerged as a possible modulator of NCKX2 expression.

HDAC4 and HDAC5 form a complex with DREAM that epigenetically down-regulates NCX3 gene and its pharmacological inhibition reduces neuronal stroke damage.

The histone deacetylases (HDACs)-dependent mechanisms regulating gene transcription of the Na/Ca exchanger isoform 3 () after stroke are still unknown. Overexpression or knocking-down of HDAC4/HDAC5 down-regulates or increases, respectively, NCX3 mRNA and protein. Likewise, MC1568 (class IIa HDACs inhibitor), but not MS-275 (class I HDACs inhibitor) increased NCX3 promoter activity, gene and protein expression.

Models and methods for conditioning the ischemic brain.

Background: In the last decades the need to find new neuroprotective targets has addressed the researchers to investigate the endogenous molecular mechanisms that brain activates when exposed to a conditioning stimulus. Indeed, conditioning is an adaptive biological process activated by those interventions able to confer resistance to a deleterious brain event through the exposure to a sub-threshold insult. Specifically, preconditioning and postconditioning are realized when the conditioning stimulus is applied before or after, respectively, the harmul ischemia.

Ionic Homeostasis Maintenance in ALS: Focus on New Therapeutic Targets.

Amyotrophic lateral sclerosis (ALS) is one of the most threatening neurodegenerative disease since it causes muscular paralysis for the loss of Motor Neurons in the spinal cord, brainstem and motor cortex. Up until now, no effective pharmacological treatment is available. Two forms of ALS have been described so far: 90% of the cases presents the sporadic form (sALS) whereas the remaining 10% of the cases displays the familiar form (fALS).

Triticum vulgare extract exerts an anti-inflammatory action in two in vitro models of inflammation in microglial cells.

Triticum vulgare has been extensively used in traditional medicine thanks to its properties of accelerating tissue repair. The specific extract of Triticum vulgare manufactured by Farmaceutici Damor (TVE-DAMOR) is already present in some pharmaceutical formulations used in the treatment of decubitus ulcers, skin lesions and burns. It has been recently suggested that this Triticum vulgare extract may possess potential anti-inflammatory properties.

Acute and long-term NCX activation reduces brain injury and restores behavioral functions in mice subjected to neonatal brain ischemia.

Hypoxic-ischemic encephalopathy (HI) accounts for the majority of developmental, motor and cognitive deficits in children, leading to life-long neurological impairments. Since the plasmamembrane sodium/calcium exchanger (NCX) plays a fundamental role in maintaining ionic homeostasis during adult brain ischemia, in the present work we aimed to demonstrate (1)the involvement of NCX in the pathophysiology of neonatal HI and (2)a possible NCX-based pharmacological intervention. HI was induced in neonatal mice at postnatal day 7(P7) by unilateral cut of the right common carotid artery, followed by 60 min exposure to 8%O.

Preconditioning, induced by sub-toxic dose of the neurotoxin L-BMAA, delays ALS progression in mice and prevents Na/Ca exchanger 3 downregulation.

Preconditioning (PC) is a phenomenon wherein a mild insult induces resistance to a later, severe injury. Although PC has been extensively studied in several neurological disorders, no studies have been performed in amyotrophic lateral sclerosis (ALS). Here we hypothesize that a sub-toxic acute exposure to the cycad neurotoxin beta-methylamino-L-alanine (L-BMAA) is able to delay ALS progression in SOD1 G93A mice and that NCX3, a membrane transporter able to handle the deregulation of ionic homeostasis occurring during ALS, takes part to this neuroprotective effect.

MC1568 Inhibits Thimerosal-Induced Apoptotic Cell Death by Preventing HDAC4 Up-Regulation in Neuronal Cells and in Rat Prefrontal Cortex.

Ethylmercury thiosalicylate (thimerosal) is an organic mercury-based compound commonly used as an antimicrobial preservative that has been found to be neurotoxic. In contrast, histone deacetylases (HDACs) inhibition has been found to be neuroprotective against several environmental contaminants, such as polychlorinated biphenyls, di-2-ethylhexyl phthalate, and methylmercury. The aim of this study was to investigate the effect of HDAC inhibition on thimerosal-induced neurotoxicity in neuroblastoma cells and cortical neurons.

Sumoylation of LYS590 of NCX3 f-Loop by SUMO1 Participates in Brain Neuroprotection Induced by Ischemic Preconditioning.

Background And Purpose: The small ubiquitin-like modifier (SUMO), a ubiquitin-like protein involved in posttranslational protein modifications, is activated by several conditions, such as heat stress, hypoxia, and hibernation and confers neuroprotection. Sumoylation enzymes and substrates are expressed also at the plasma membrane level. Among the numerous plasma membrane proteins controlling ionic homeostasis during cerebral ischemia, 1 of the 3 brain sodium/calcium exchangers (NCX3), exerts a protective role during ischemic preconditioning.

Methylmercury upregulates RE-1 silencing transcription factor (REST) in SH-SY5Y cells and mouse cerebellum.

Methylmercury (MeHg) is a highly neurotoxic compound that, in adequate doses, can cause damage to the brain, including developmental defects and in severe cases cell death. The RE-1-silencing transcription factor (REST) has been found to be involved in the neurotoxic effects of environmental pollutants such as polychlorinated biphenyls (PCBs). In this study, we investigated the effects of MeHg treatment on REST expression and its role in MeHg-induced neurotoxicity in neuroblastoma SH-SY5Y cells.

Ionic homeostasis in brain conditioning.

Most of the current focus on developing neuroprotective therapies is aimed at preventing neuronal death. However, these approaches have not been successful despite many years of clinical trials mainly because the numerous side effects observed in humans and absent in animals used at preclinical level. Recently, the research in this field aims to overcome this problem by developing strategies which induce, mimic, or boost endogenous protective responses and thus do not interfere with physiological neurotransmission.