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Background Our previous research confirmed that electroacupuncture (EA) stimulus elicits neuroprotective effects against cerebral ischemic injury through α7 nicotinic acetylcholine receptor (α7nAChR)-mediated inhibition of high-mobility group box 1 release mechanism. This study investigated whether the signal transducer of α7nAChR and inhibition of NLRP3 inflammasome are involved in the neuroprotective effects of EA stimulus. Methods In adult male Sprague-Dawley rats, the focal cerebral ischemic injury was induced by middle cerebral artery occlusion (MCAO) models for 1.5 h. The expression of NLRP3 inflammasome in the penumbral tissue following reperfusion was assessed by western blotting and immunoflourescent staining. The infarct size, neurological deficit score, TUNEL staining and the expression of proinflammatory factors or anti-inflammatory cytokines were evaluated at 72 h after reperfusion in the presence or absence of either α7nAChR antagonist (α-BGT) or agonist (PHA-543,613). Results The contents of inflammasome proteins were gradually increased after cerebral ischemia/reperfusion (I/R). EA stimulus attenuated NLRP3 inflammasome mediated inflammatory reaction and regulated the balance between proinflammatory factors and anti-inflammatory cytokines. The agonist of α7nAChR induced similar neuroprotective effects as EA stimulus. In contrast, α7nAChR antagonist reversed not only the neuroprotective effects, but also the inhibitory effects of NLRP3 inflammasome and the regulatory effects on the balance between proinflammatory factors and anti-inflammatory cytokines. Conclusions These results provided compelling evidence that α7nAChR played a pivotal role in regulating the activation and expression of NLRP3 inflammasome in neurons after cerebral I/R. These findings highlighted a novel anti-inflammatory mechanism of EA stimulus by α7nAChR modulating the inhibition of NLRP3 inflammasome, suggesting that α7nAChR-dependent cholinergic anti-inflammatory system and NLRP3 inflammasome in neurons might act as potential therapeutic targets in EA induced neuroprotection against cerebral ischemic injury.

Diabetes-associated cognitive impairment (DACI) can increase the risk of major cardiovascular events and death. Neuronal functionality is highly dependent on mitochondria and emerging evidence has shown that mitochondrial transplantation is a potential and effective strategy that can reduce brain injury and associated disorders. Platelets are abundant in blood and can be considered a readily available source of small-size mitochondria. These cells can be easily acquired from the peripheral blood with minimal invasion via simple venipuncture. The present study aimed to investigate whether transplantation of platelet-derived mitochondria (Mito-Plt) could improve DACI. Cognitive behaviors were assessed using the Morris water maze test in db/db mice. The results demonstrated that Mito-Plt was internalized into hippocampal neurons 24 h following intracerebroventricular injection. Importantly, one month following Mito-Plt transplantation, DACI was alleviated in db/db mice and the effect was accompanied with increased mitochondrial number, restored mitochondrial function, attenuated oxidative stress and neuronal apoptosis, as well as decreased accumulation of Aβ and Tau in the hippocampus. Taken together, the data demonstrated that transplantation of Mito-Plt attenuated cognitive impairment and mitochondrial dysfunction in db/db mice. This method may be a potential therapeutic application for the treatment of DACI.

Background: Mitochondrial transplantation is a promising strategy for the treatment of several diseases. However, the effects of mitochondrial transplantation on the outcome of polymicrobial sepsis remain unclear. Methods: The distribution of transplanted mitochondria in cecal ligation and puncture (CLP)-operated mice was detected at 2 and 12 h after intravenous injection in the tail (n ¼ 3). Then, the effects of mitochondrial transplantation on bacterial clearance (n ¼ 7), systemic inflammation (n ¼ 10), organ injury (n ¼ 8), and mortality (n ¼ 19) during CLP-induced sepsis were explored. Microarray analysis (n ¼ 3) was used to testify the molecular changes associated with decreased systemic inflammation and multiorgan dysfunction in sepsis. Results: The extraneous mitochondria were distributed in the lung, liver, kidney, and brain of CLP-operated mice at 2 and 12 h after intravenous injection in the tail. Mitochondrial transplantation increased the survival rate of septic mice, which was associated with decreased bacterial burden, systemic inflammation, and organ injury. Spleen samples were utilized for microarray analysis. Pathway analysis revealed that in polymicrobial sepsis, gene expression was significantly changed in processes related to inflammatory response, complement and coagulation cascades, and rejection reaction. Conclusions: These data displayed that mitochondrial replenishment reduces systemic inflammation and organ injury, enhances bacterial clearance, and improves the survival rate in sepsis. Thus, extraneous mitochondrial replenishment may be an effective adjunctive treatment to reduce sepsis-related mortality.

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