Excessive microglial activation often contributes to inflammation-mediated neurotoxicity in the ischemic penumbra during the acute stage of ischemic stroke. Toll-like receptor 4 (TLR4) has been reported to induce microglial activation via the NF-κB pathway. Isoflurane preconditioning (IP) can provide neuroprotection and inhibit microglial activation. In this study, we investigated the roles of the TLR4 signalling pathway in IP to exert neuroprotection following ischemic stroke in vivo and in vitro. The results showed that 2% IP alleviated neurological deficits, reduced the infarct volume, attenuated apoptosis and weakened microglial activation in the ischemic penumbra. Furthermore, IP down-regulated the expression of HSP 60, TLR4 and MyD88 and up-regulated inhibitor of IκB-α expression compared with I/R group in vivo. In vitro, 2% IP and a specific inhibitor of TLR4, CLI-095, down-regulated the expression of TLR4, MyD88, IL-1β, TNF-α and Bax and up-regulated IκB-α and Bcl-2 expression compared with OGD group. Moreover, IP and CLI-095 attenuated microglial activation-induced neuronal apoptosis and overexpression of the TLR4 gene reversed the neuroprotective effects of IP. In conclusion, IP provided neuroprotection by regulating TLR4 expression directly, alleviating microglial activation and neuroinflammation. Thus, inhibiting the activation of microglial activation via TLR4 may be a new avenue for stroke treatment.

Background: Stroke remains a leading cause of adult disability and the demand for stroke rehabilitation services is growing, and Astragaloside IV (As IV), a primary bioactive compound of Radix Astragali : Astragalus mongholicus Bunge (Fabaceae), may be a promising stroke therapy. Methods: To access the effect of As IV on adult mice after ischemic stroke, a photochemical ischemia model was established on C57BL/6 mice, which were intravenously administered As IV for three consecutive days later. And then the cognitive benefits and hippocampal neurogenesis were evaluated by Morris Water Maze (MWM) test, Golgi staining, and immunohistochemical staining in vivo and in vitro. Furthermore, to find out the underlying mechanism, interleukin-17 (IL-17) knockout (KO) mice were used, through RNA sequence (RNA-seq) analysis and immunohistochemistry. Then the mechanism of neurogenesis promoted by As IV was observed by western blot both in vivo and in vitro. Specifically, As IV, recombinant mouse IL-17A and IL-17F, and Wingless/integrated (Wnt)-expressing virus was administered respectively in neural stem cells (NSCs), and then their diameters and protein expression of Nestin, IL-17, and Wnt pathway relevant protein, were measured in vitro. Results: Administering As IV resulted in significant amelioration of stroke-induced cognitive deficits. And more hippocampal neurons with normal morphology, significant increments in the length of the apical dendrites, and the density of their spines were observed in As IV-treated mice. Furthermore, the immunohistochemistry staining of DCX/BrdU and Sox2/Nestin showed As IV could promote hippocampal neurogenesis and NSC proliferation after ischemic stroke, as well as in vitro. For the mechanism underlying, IL-17 expression was downregulated significantly by As IV treatment and knocking out IL-17 was associated with nervous regeneration and synapse repair according to the analysis of RNA-seq. Consistent to As IV treatment, knocking out IL-17 showed some promotion on hippocampal neurogenesis and proliferation of NSCs, with activating Wnt pathway after stoke. Finally, in vitro, NSCs’ diameters and protein expression of Nestin, IL-17, and Wnt pathway were regulated by either administering As IV or inhibiting IL-17. Conclusion: As IV stimulates hippocampal neurogenesis after stroke, thus potentially facilitates brain to remodel and repair by downregulating IL-17 expression via Wnt pathway.

We aimed to investigate the exact effect of IL-17 on regulating neural stem cells (NSCs) stemness and adult neurogenesis in ischemic cortex after stroke, how Astragaloside IV(As-IV) regulated IL-17 expression and the underlying mechanism. Photochemical brain ischemia model was established and IL-17 protein expression was observed at different time after stroke in WT mice. At 3 days after stroke, when IL-17 expression peaked, IL-17 knock out (KO) mice were used to observe cell proliferation and neurogenesis in ischemic cortex. Then, As-IV was administered intravenously to assess cell apoptosis, proliferation, neurogenesis, and cognitive deficits by immunochemistry staining, western blots, and animal behavior tests in WT mice. Furthermore, IL-17 KO mice and As-IV were used simultaneously to evaluate the mechanism of cell apoptosis and proliferation after stroke in vivo. Besides, in vitro, As-IV and recombinant mouse IL-17A was administered, respectively, into NSCs culture, and then their diameters, viable cell proliferation and pathway relevant protein was assessed. The results showed knocking out IL-17 contributed to regulating PI3K/Akt pathway, promoting NSCs proliferation, and neurogenesis after ischemic stroke. Moreover, As-IV treatment helped inhibit neural apoptosis, promote the neurogenesis and eventually relieve mice anxiety after stroke. Unsurprisingly, IL-17 protein expression could be downregulated by As-IV in vivo and in vitro and they exerted antagonistic effect on neurogenesis by regulating Akt/GSK-3β pathway, with significant regulation for apoptosis. In conclusion, IL-17 exerts negative effect on promoting NSCs proliferation, neurogenesis and cognitive deficits after ischemic stroke, which could be reversed by As-IV.

This trial was to examine the effect of transcutaneous electrical acupoint stimulation (TEAS) on postoperative cognitive function in older patients who underwent thoracoscopic pulmonary resection. This was a prospective, randomized, double-blind, placebo-controlled study. 128 patients scheduled for surgery were randomly assigned to the TEAS group and sham-TEAS group. A standardized intervention of TEAS or sham-TEAS on the acupoints of Baihui (DU20) and bilateral Neiguan (PC6), Hegu (LI4), and Zusanli (ST36) from 30 min before anesthesia induction until the end of the surgery, combined with a general anesthetic protocol performed in the two groups respectively. The primary outcome was the incidence of postoperative cognitive dysfunction (POCD) assessed via the Montreal Cognitive Assessment (MoCA) scale at each time point. The secondary outcomes included the results of the Mini-Mental State Examination (MMSE) score, the Numerical Rating Scale (NRS) on pain and sleep, the European Organization for Research and Treatment of Cancer Quality of Life (EORTC-QLQ-C30), and a chronic pain questionnaire at relative time points. Participants who completed the 12-month trial of the two groups were well-matched in baseline demographic and clinical parameters. At postoperative day 1, day 7, and day 30 time points, the incidence of POCD in the sham-TEAS group was always significantly higher than in the TEAS group (65.4% vs 20%, 43.6% vs 7.3%, 40% vs 3.6%, all P < 0.001). Also, the TEAS group showed better scores of MMSE, sleep, and pain compared with the sham-TEAS group (all P < 0.001). At 6 and 12 months points, the global health scores of the TEAS group were still significantly higher than the sham-TEAS group, and the prevalence of chronic pain was significantly lower than the sham-TEAS group (all P < 0.05). TEAS could effectively improve the postoperative cognitive function and long-term life quality of geriatric patients with lung cancer.