Irisin — the future of ischemic stroke therapy?

Irisin is a recently discovered hormone, synthesized mainly by the muscles. Expression of irisin and its precursor named FNDC5 was also found in the heart, kidneys, liver, pancreas, adipose tissue, and brain including cortical neurons, hippocampus, cerebellum, hypothalamus, and spinal cord. The purpose of this study is to review the latest research on the properties of the irisin and its cytoprotective effect against neuronal damage and to draw attention to its possible clinical use in the treatment of stroke. Notch pathway activity increases after ischemic damage, stimulating the repair of the affected brain area. Irisin activates the Notch pathway which inhibits the activity of microglia, secretion of inflammatory factors, and finally leads to reduction of the brain edema. Studies revealed that irisin increases levels of brain-derived neurotrophic factor (BDNF), leading to enhancement of survival and migration of the neurons, and protecting nerve cells from damage during the ischemic stroke. It was also found that irisin maintains mitochondrial integrity, reduces oxidative stress, and exerts a protective effect on the blood-brain barrier. Irisin entails a neuroprotective effect, reducing the extent of the infarcted area and the degree of brain damage. Stimulation of the irisin expression by physical activity or its exogenous administration remains the subject of research that raises hope for development of the new therapeutic options for diseases, especially ischemic stroke

The Dynamics of the Defense Strategy of Pea Induced by Exogenous Nitric Oxide in Response to Aphid Infestation

The aim of this study was to investigate the effect of exogenous nitric oxide (NO), i.e., S-nitrosoglutathione (GSNO) and sodium nitroprusside (SNP), on the metabolic status of Pisum sativum L. cv. Cysterski leaves infested by Acyrthosiphon pisum Harris, population demographic parameters and A. pisum feeding activity. A reduction in the level of semiquinone radicals in pea seedling leaves pretreated with exogenous NO occurred 24 h after A. pisum infestation, which was earlier than in non-pretreated leaves. A decrease in the level of O2•− was observed in leaves pretreated with GSNO and infested by aphids at 48 and 72 h post-infestation (hpi). Directly after the pretreatment with GSNO, an increase in the level of metal ions was recorded. NO considerably induced the relative mRNA levels for phenylalanine ammonia-lyase in 24-h leaves pretreated with NO donors, both non-infested and infested. NO stimulated the accumulation of pisatin in leaves until 24 h. The Electrical Penetration Graph revealed a reduction in the feeding activity of the pea aphid on leaves pretreated with NO. The present study showed that foliar application of NO donors induced sequentially defense reactions of pea against A. pisum and had a deterrent effect on aphid feeding and limited the population growth rate