Septic encephalopathy (SE) is a critical factor determining sepsis mortality. Vascular inflammation is known to be involved in SE, but the molecular events that lead to the development of encephalopathy remain unclear. Using time-lapse in vivo two-photon laser scanning microscopy, we provide the first direct evidence that cecal ligation and puncture in septic mice induces microglial trafficking to sites adjacent to leukocyte adhesion on inflamed cerebral microvessels. Our data further demonstrate that septic injury increased the chemokine CXCL1 level in brain endothelial cells by activating endothelial P2RX7 and eventually enhanced the binding of Mac-1 (CD11b/CD18)-expressing leukocytes to endothelial ICAM-1. In turn, leukocyte adhesion upregulated endothelial CX3CL1, thereby triggering microglia trafficking to the injured site. The sepsis-induced increase in endothelial CX3CL1 was abolished in CD18 hypomorphic mutant mice. Inhibition of the P2RX7 pathway not only decreased endothelial ICAM-1 expression and leukocyte adhesion but also prevented microglia overactivation, reduced brain injury, and consequently doubled the early survival of septic mice. These results demonstrate the role of the P2RX7 pathway in linking neurovascular inflammation to brain damage in vivo and provide a rationale for targeting endothelial P2RX7 for neurovascular protection during SE.

Highlights d Endothelium-derived Sema3G is necessary for synaptic plasticity in the hippocampus d Loss of Sema3G in the vascular endothelium results in behavioral and memory deficits d Sema3G regulates synaptic structure and function via the neuropilin-2/PlexinA4 receptor d Sema3G functionally links the endothelium to signaling cascades activated in neurons

A rapid induction in autophagy in human brain vascular pericytes, in the zinc oxide nanoparticles (ZnO-NP)-induced cell stress model, was paralleled with an increase in the expression of the TRPM2-S truncated isoform, which was abolished by treatment with a nitric oxide synthase inhibitor and a peroxynitrite scavenger. Furthermore, Y1485 in the C-terminus of the TRPM2 protein was identified as the tyrosine nitration substrate by mass spectrometry. Overexpression of the Y1485S TRPM2 mutant reduced LC3-II accumulation and pericyte injury induced by ZnO-NP. Consistently, LC3-II accumulation was reduced and pericytes were better preserved in intact brain microvessels of the TRPM2 knockout mice after ZnO-NP-induced vascular injury. Innovation and Conclusions: Our present study has revealed a novel mechanism of autophagy disturbance secondary to nitrosative stress-induced tyrosine nitration of TRPM2 during pericyte injury. Antioxid. Redox Signal. 27, 1297-1316.

Lung cancer is one of the most common malignancies in the world and its metastasis is the major cause of death in cancer patients. Acacetin (5,7-dihydroxy-4'-methoxyflavone), a flavonoid compound, has anti-peroxidative and anti-inflammatory effects. The effect of acacetin on invasion and migration in human NSCLC A549 cells was investigated. First, the result demonstrated acacetin could exhibit an inhibitory effect on the abilities of the adhesion, morphology/actin cytoskeleton arrangement, invasion, and migration by cell-matrix adhesion assay, immunofluorescence assay, Boyden chamber assay, and wound-healing assay. Molecular data showed that the effect of acacetin in A549 cells might be mediated via sustained inactivation of the phosphorylation of mixed-lineage protein kinase 3 (MLK3), mitogen-activated protein kinase kinases 3/6 (MKK3/6), and p38α MAPK signal involved in the downregulation of the expressions of matrix metalloproteinase-2 (MMP-2), matrix metalloproteinase-9 (MMP-9), and urokinase-type plasminogen activator (u-PA). Next, acacetin significantly decreased in the phosphorylation and degradation of inhibitor of kappaBα (IκBα), and the nuclear levels of nuclear factor kappa B (NF-κB), c-Fos, and c-Jun. Also, the treatment with acacetin to A549 cells also leads to a concentration-dependent inhibition on the binding abilities of NF-κB and activator protein-1 (AP-1). Furthermore, the treatment of specific inhibitor for p38 MAPK (SB203580) to A549 cells could cause reduced activities of MMP-2/9 and u-PA. In addition, acacetin significantly decreased the levels of phospho-p38α MAPK, MMP-2/9, and u-PA in p38α-cDNA-transfected cells concomitantly with a marked reduction on cell invasion and migration. Our results revealed the anti-migration and anti-invasion effects of acacetin, which may act as a promising therapeutic agent for the treatment of lung cancer.

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