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Fingolimod has generally shown neuroprotective effects in stroke models. Here, we tested the hypothesis that fingolimod modulates T‐cell cytokine production towards a regulatory phenotype. Second, we investigated how fingolimod altered the Treg suppressive function and the sensitivity of effector T cells to regulation. Mice that had underwent the permanent electrocoagulation of the left middle cerebral artery received saline or fingolimod (0.5 mg/kg) daily for 10‐days post‐ischaemia. Fingolimod improved neurobehavioural recovery compared to saline control and increased Treg frequency in the periphery and brain. Tregs from fingolimod‐treated animals had a higher expression of CCR8. Fingolimod increased the frequencies of CD4+IL‐10+, CD4+ IFN‐γ+ and CD4+IL‐10+IFN‐γ+ cells in spleen and blood, and CD4+ IL‐17+ cells in the spleen, with only minor effects on CD8+ T‐cell cytokine production. Treg from post–ischaemic mice had reduced suppressive function compared to Treg from non‐ischaemic mice. Fingolimod treatment rescued this function against saline‐treated but not fingolimod‐treated CD4+ effector T cells. In conclusion, fingolimod seems to improve the suppressive function of Treg post‐stroke while also increasing the resistance of CD4+ effector cells to this suppression. Fingolimod's capacity to increase both effector and regulatory functions may explain the lack of consistent improvement in functional recovery in experimental brain ischaemia. [ABSTRACT FROM AUTHOR]

Migraine is a leading cause of disability in more than one billion people worldwide, yet it remains universally underappreciated, even by individuals with the condition. Among other shortcomings, current treatments (often repurposed agents) have limited efficacy and potential adverse effects, leading to low treatment adherence. After the introduction of agents that target the calcitonin gene-related peptide pathway, another new drug class, the ditans — a group of selective serotonin 5-HT1F receptor agonists — has just reached the international market. Here, we review preclinical studies from the late 1990s and more recent clinical research that contributed to the development of the ditans and led to their approval for acute migraine treatment by the US Food and Drug Administration and the European Medicines Agency. Ditans are a recently developed drug class for the treatment of acute migraine. In this Review, the authors provide an overview of ditan development, from the initial rationale to the clinical studies that led to the recent FDA approval of the first ditan. Key points: Various animal studies have shown that selective agonists for the serotonin 5-HT1F receptor can reduce signals from an activated trigeminovascular system, thereby highlighting the receptor as an attractive target for symptomatic treatment of migraine. Long-term clinical studies involving two ditans — a group of 5-HT1F agonists — have provided class I evidence that lasmiditan, the first ditan, is both effective and safe in the symptomatic treatment of migraine. The 5-HT1F receptor is expressed by cells within the brain parenchyma, as well as by the trigeminal neurons, but not in vascular smooth muscle, suggesting that ditans act through neuropeptide release leading to acute headache relief, rather than via potential vasoactive properties, such as vasodilatation. Dizziness is the most common adverse event of lasmiditan; thus people should not drive for 8 h after taking lasmiditan. Development of novel ditans that do not cross the blood–brain barrier is expected to result in better tolerability and improved clinical use. [ABSTRACT FROM AUTHOR]

Neovascular ocular diseases (such as age-related macular degeneration, diabetic retinopathy and retinal vein occlusion) are characterised by common pathological processes that contribute to disease progression. These include angiogenesis, oedema, inflammation, cell death and fibrosis. Currently available therapies target the effects of vascular endothelial growth factor (VEGF), the main mediator of pathological angiogenesis. Unfortunately, VEGF blockers are expensive biological therapeutics that necessitate frequent intravitreal administration and are associated with multiple adverse effects. Thus, alternative treatment options associated with fewer side effects are required for disease management. This review introduces sphingosine 1-phosphate (S1P) as a potential pharmacological target for the treatment of neovascular ocular pathologies. S1P is a sphingolipid mediator that controls cellular growth, differentiation, survival and death. S1P actions are mediated by five G protein-coupled receptors (S1P1-5 receptors) which are abundantly expressed in all retinal and subretinal structures. The action of S1P on S1P1 receptors can reduce angiogenesis, increase endothelium integrity, reduce photoreceptor apoptosis and protect the retina against neurodegeneration. Conversely, S1P2 receptor signalling can increase neovascularisation, disrupt endothelial junctions, stimulate VEGF release, and induce retinal cell apoptosis and degeneration of neural retina. The aim of this review is to thoroughly discuss the role of S1P and its different receptor subtypes in angiogenesis, inflammation, apoptosis and fibrosis in order to determine which of these S1P-mediated processes may be targeted therapeutically. [ABSTRACT FROM AUTHOR]

Familial hemiplegic migraine type 1 (FHM1) is an autosomal dominant subtype of migraine with aura that is associated with hemiparesis. As with other types of migraine, it affects women more frequently than men. FHM1 is caused by mutations in the CACNA1A gene, which encodes the [[alpha].sub.1A] subunit of [Ca.sub.v]2.1 channels; the R192Q mutation in CACNA1A causes a mild form of FHM1, whereas the S218L mutation causes a severe, often lethal phenotype. Spreading depression (SD), a slowly propagating neuronal and glial cell depolarization that leads to depression of neuronal activity, is the most likely cause of migraine aura. Here, we have shown that transgenic mice expressing R192Q or S218L FHM1 mutations have increased SD frequency and propagation speed; enhanced corticostriatal propagation; and, similar to the human FHM1 phenotype, more severe and prolonged post-SD neurological deficits. The susceptibility to SD and neurological deficits is affected by allele dosage and is higher in S218L than R192Q mutants. Further, female S218L and R192Q mutant mice were more susceptible to SD and neurological deficits than males. This sex difference was abrogated by ovariectomy and senescence and was partially restored by estrogen replacement, implicating ovarian hormones in the observed sex differences in humans with FHM1. These findings demonstrate that genetic and hormonal factors modulate susceptibility to SD and neurological deficits in FHM1 mutant mice, providing a potential mechanism for the phenotypic diversity of human migraine and aura., Introduction Spreading depression (SD) is characterized by an intense depolarization of neuronal and glial membranes that propagates in brain tissue at a rate of approximately 3 mm/min (1), (2). Evoked [...]

Preclinical data indicate that fingolimod improves outcome post-ischaemia. This study used a rigorous study design in normal male C57BL/6JOlaHsd mice and in mice with common stroke comorbidities to further evaluate the translational potential of fingolimod. Stroke was induced via middle cerebral artery electrocoagulation in 8-9-week old mice (young mice), 18 month old mice (aged mice), and in high-fat diet-fed 22-week old ApoE-/- mice (hyperlipidaemic mice). Recovery was evaluated using motor behavioural tests 3 and 7 days after stroke. Tissue damage was evaluated at 7 days. A lower dose of fingolimod, 0.5 mg/kg, but not 1 mg/kg, increased lesion size but decreased ipsilateral brain atrophy in younger mice, without an effect on behavioural outcomes. Fingolimodtreated aged mice showed a significant improvement over saline-treated mice in the foot fault test at 7 days. Fingolimod-treated hyperlipidaemic mice showed a decreased infarct size but no difference in behavioural performance. Increasing fingolimod treatment time to 10 days showed no benefit in young mice. Pooled data showed that fingolimod improved performance in the foot fault test. Flow cytometry studies showed that fingolimod had marked effects on T cell frequencies in various tissues. The results show that the effects of fingolimod in stroke are less robust than the existing literature might indicate and may depend on the inflammatory status of the animals. [ABSTRACT FROM AUTHOR]

The mechanism of acetyl-choline induced arterial dilatation is investigated in the pial arteries of mice in vitro. Inhibiting the neuronal nitric oxide synthase (NOS) in mutant mice without the endothelial isozyme of NOS inhibited the arteriolar dilatation mediated by acetyl choline administration. This indicates that neuronal NOS compensate for endothelial NOS in this strain of mutant mice.

Fine timing of signal transduction was demonstrated by cDNA expressed in altered patterns of phospholiphase C activation and adenyl cyclase stimulation. The type I pituitary adenylyl cyclase-activating polypeptide receptor was encoded by a complementary DNA, which was isolated on the basis of the induction of a reporter gene by cyclic AMP, by employing a novel expression cloning technique. The C-terminal section of the third intracellular loop revealed four splice variants isolated with insertions.

Stroke is a major cause of morbidity and mortality worldwide. Despite the intensive search for new therapies, hundreds of agents targeting various pathophysiological mechanisms have failed clinical trials, and the thrombolytic agent tissue plasminogen activator is currently the only FDA‐approved medication for the treatment of acute ischemic stroke. The immune system is involved in all stages of stroke, from the pathogenesis of risk factors to neurotoxicity, to tissue remodeling and repair. There is a bidirectional interaction between the brain and the immune system, with stroke‐induced immunosuppression and subsequent infection a principal source of patient mortality. Newer work also points to a role for the gut microbiota in the immune response to stroke, while clinical sequelae such as dementia might now also be explained in immune terms. However, the exact roles of innate and adaptive components have not been fully elucidated, with studies reporting both detrimental and beneficial functions. Time is a key determinant in defining whether immunity and inflammation are neuroprotective or neurotoxic. The local inflammatory milieu also has a clear influence on many proposed treatments. This review examines the individual components of the immune response to stroke, highlighting the most promising future stroke immunotherapies. Acute ischemic stroke is a major cause of morbidity and mortality worldwide, and yet the thrombolytic agent tissue plasminogen activator is currently the only FDA‐approved medication. The immune system is involved in all stages of stroke, from the pathogenesis of risk factors to neurotoxicity, to tissue remodeling and repair. This review examines the individual components of the immune response to stroke, highlighting the most promising future stroke immunotherapies. [ABSTRACT FROM AUTHOR]

Glutamate excitotoxicity, metabolic rate and inflammatory response have been associated to the deleterious effects of temperature during the acute phase of stroke. So far, the association of temperature with these mechanisms has been studied individually. However, the simultaneous study of the influence of temperature on these mechanisms is necessary to clarify their contributions to temperature-mediated ischemic damage. We used non-invasive Magnetic Resonance Spectroscopy to simultaneously measure temperature, glutamate excitotoxicity and metabolic rate in the brain in animal models of ischemia. The immune response to ischemia was measured through molecular serum markers in peripheral blood. We submitted groups of animals to different experimental conditions (hypothermia at 33°C, normothermia at 37°C and hyperthermia at 39°C), and combined these conditions with pharmacological modulation of glutamate levels in the brain through systemic injections of glutamate and oxaloacetate. We show that pharmacological modulation of glutamate levels can neutralize the deleterious effects of hyperthermia and the beneficial effects of hypothermia, however the analysis of the inflammatory response and metabolic rate, demonstrated that their effects on ischemic damage are less critical than glutamate excitotoxity. We conclude that glutamate excitotoxicity is the key molecular mechanism which is influenced by body temperature during the acute phase of brain stroke. [ABSTRACT FROM AUTHOR]