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• Irisin alleviates morphological damage and improves neurological function after global cerebral I/R injury in mice. • Irisin inhibits post-ischemic inflammation and neuronal apoptosis after cerebral I/R injury in vivo and in vitro. • Irisin activates canonical Notch signaling pathway to exert its neuroprotective effects. Irisin, a 112-amino acid peptide induced with exercise in mice and human is thought to have correlation with the short-term outcomes of patients in ischemic stroke. In the present study, the neuroprotective effects of irisin were evaluated in vivo and in vitro and its underlying mechanism was also explored. The global cerebral ischemia/reperfusion (I/R) model was established by bilateral common carotid artery occlusion for 20 min and reperfusion for 24 h in mice and oxygen-glucose deprivation/reperfusion in HT22 cells. Neurological function was scored and then the mice were sacrificed. The brains were harvested for HE staining and detection of brain water content (BWC). The percentage of neuronal apoptosis was evaluated by TUNEL and flow cytometry analysis. The mRNA expression of TNF-α and IL-1β was detected by RT-PCR analysis. The Notch intracellular domain (NICD) was detected by double immunofluorescence staining and western blot, and the protein expression of Notch1 and Hes 1 was detected by western blot. It was observed that irisin could alleviate morphological damage and improve neurological function after global cerebral I/R injury in mice. The apoptosis of hippocampal neurons reduced in the presence of irisin in vivo and in vitro. Additionally irisin could downregulate the expression of IL-1β and TNF-α and upregulate the expression of NICD, Notch1 and Hes 1 in vitro and in vivo. After the application of γ-secretase inhibitor DAPT, all the morphological, neurological and biochemical changes were reversed. Taken together, these results suggest that irisin could regulate the Notch signaling pathway that leads to the alleviation of transient global cerebral I/R injury. [ABSTRACT FROM AUTHOR]

• Irisin improves pulmonary epithelial barrier permeability in LPS-induced rats. • Irisin up-regulates the expression of tight junctions in vivo and in vitro. • Irisin inhibites LPS-induced inflammation and apoptosis in vivo and in vitro. • Irisin activites AMPK/SIRT1 pathway. Alveolar epithelial barrier dysfunction in response to inflammatory reaction contributes to pulmonary edema in acute lung injury(ALI).Irisin,a newly-found myokine,exerts the anti-inflammatory effects. This study aims to investigate the protective effects of irisin on lipopolysaccharide (LPS)-induced ALI in vivo and in vitro , and to explore its underlying mechanism. Male SD rats and A549 cells were divided into 4 groups: control group, LPS group, Irisin pretreated group, and Irisin/Compound C(a special inhibitor of AMPK)-treated group. The ALI model was established by intravenous injection of LPS in rats, and LPS challenge in A549 cells. Pulmonary specimens were harvested for microscopic examination of the pathological changes, and the expression of AMPK,SIRT1,NF-κB, p66Shc and caspase-3 in lung tissues. The pulmonary permeability were examined by wet/dry lung weight ratio(W/D) and lung permeability index(LPI). The apoptotic index, and the expression of tumor necrosis factor-α(TNF-α), interleukin-1β(IL-1β), monocyte chemoattractant activating protein-1 (MCP-1), tight junctions (occludin,ZO-1) were determined both in lung tissue and A549 cells. Irisin alleviated lung histological changes and decreased pulmonary microvascular permeability in LPS-induced rats. Irisin up-regulated the expression of occludin, ZO-1,AMPK,SIRT1, down-regulated the expression of TNF-α,IL-1β,MCP-1,NF-κB, p66Shc caspase-3, and decreased the apoptotic index in LPS-induced rats and A549 cells. All these protective effects of irisin could be reversed by Compound C. Irisin improved LPS-induced alveolar epithelial barrier dysfunction via suppressing inflammation and apoptosis, and this protective effect might be mediated by activating AMPK/SIRT1 pathways. [ABSTRACT FROM AUTHOR]

Background Ketamine is an anesthetic commonly used in both humans and animals. Emerging evidence has demonstrated that ketamine may induce neurotoxicity in neural stem cell-derived neurons. In this work, we investigated whether long noncoding RNA (lncRNA) Brain derived neurotrophic factor antisense (BDNF-AS) was involved in ketamine-induced neurotoxicity in differentiation of mouse embryonic neural stem cells. Methods Mouse embryonic neural stem cells were differentiated in vitro , and treated with ketamine. The corresponding change in gene expression levels of BDNF and BDNF-AS were assessed by qRT-PCR. BDNF-AS was subsequently downregulated by siRNA. And its effect on protecting neuronal apoptosis, promoting neurite regrowth, and activating TrkB signaling pathways were assessed by TUNEL assay, neurite outgrowth assay, and western blot assay, respectively. Results In ketamine-injured mouse embryonic neural stem cell-derived neurons, BDNF was downregulated, whereas BDNF-AS was upregulated in dose-dependent manner. SiRNA-mediated BDNF-AS downregulation ameliorated neuronal apoptosis, induced neurite outgrowth, and phosphorylated TrkB signaling pathway after ketamine-induce neurotoxicity in mouse embryonic neural stem cell-derived neurons. Conclusions Inhibition of BDNF-AS is a novel method to protect ketamine-induced neurotoxicity in mouse embryonic neural stem cell-derived neurons, very likely through the activation of TrkB signaling pathway. [ABSTRACT FROM AUTHOR]