Astrocyte-derived exosomes suppress autophagy and ameliorate neuronal damage in experimental ischemic stroke.

The aim of this study was to investigate the role of astrocyte-derived exosomes (AS-Exo) on neuronal damage in ischemic stroke. We isolated astrocytes from 3- to 4-day-old C57BL/6 mice and astrocytes were identified by GFAP immunostaining. Exosomes were obtained from astrocyte supernatant by overspeed centrifugation. For investigating the effect of AS-Exo on the apoptosis of neurons after oxygen and glucose deprivation (OGD), the exosome labeling and uptake by neurons were observed by confocal laser microscopy, then HT-22 cell vitality and apoptosis were determined by Cell Counting Kit-8 (CCK-8) assay and Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining, respectively. Tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1ß (IL-1ß) in OGD-induced HT-22 was analyzed by Enzyme-linked immunosorbent assay (ELISA). Apoptosis-related protein in HT-22 was analyzed by Western blot. For investigating the effect of AS-Exo on the OGD neurons autophagy, expression of Beclin-1, LC3-I, LC3-II and P62 in OGD-induced HT-22 was analyzed by Western blot. For animal experiments, C57BL/6 mice (6-8 weeks old) models of middle cerebral artery occlusion were used to create permanent focal ischemia. AS-Exo were injected intravenously through the tail vein into ischemic mice at a concentration of 80 µg per 2 ml after 60 min of the ligation operation The results showed that AS-Exo enhanced neurons viability; inhibited OGD-induced apoptosis, inhibited OGD-induced expressions of caspase-3 and Bax and levels of TNF-α, IL-6 and IL-1ß in HT-22 cells. Further findings showed AS-Exo inhibited OGD-induced neurons apoptosis via regulating autophagy. AS-Exo ameliorated neuronal damage through regulating autophagy in vivo. Our data indicate that AS-Exo suppress autophagy and ameliorate neuronal damage in experimental ischemic stroke.

One-stop stroke management platform reduces workflow times in patients receiving mechanical thrombectomy.

Background and purpose: Clinical outcome in patients who received thrombectomy treatment is time-dependent. The purpose of this study was to evaluate the efficacy of the one-stop stroke management (OSSM) platform in reducing in-hospital workflow times in patients receiving thrombectomy compared with the traditional model. Methods: The data of patients who received thrombectomy treatment through the OSSM platform and traditional protocol transshipment pathway were retrospectively analyzed and compared. The treatment-related time interval and the clinical outcome of the two groups were also assessed and compared. The primary efficacy endpoint was the time from door to groin puncture (DPT). Results: There were 196 patients in the OSSM group and 210 patients in the control group, in which they were treated by the traditional approach. The mean DPT was significantly shorter in the OSSM group than in the control group (76 vs. 122 min; P < 0.001). The percentages of good clinical outcomes at the 90-day time point of the two groups were comparable (P = 0.110). A total of 121 patients in the OSSM group and 124 patients in the control group arrived at the hospital within 360 min from symptom onset. The mean DPT and time from symptom onset to recanalization (ORT) were significantly shorter in the OSSM group than in the control group. Finally, a higher rate of good functional outcomes was achieved in the OSSM group than in the control group (53.71 vs. 40.32%; P = 0.036). Conclusion: Compared to the traditional transfer model, the OSSM transfer model significantly reduced the in-hospital delay in patients with acute stroke receiving thrombectomy treatment. This novel model significantly improved the clinical outcomes of patients presenting within the first 6 h after symptom onset.

Astrocyte-derived exosomes transfer miR-190b to inhibit oxygen and glucose deprivation-induced autophagy and neuronal apoptosis.

Our previous work has verified that astrocytes (AS)-derived exosomes (AS-Exo) inhibited autophagy and ameliorated neuronal damage in experimental ischemic stroke. However, the mechanism of AS-Exo regulation of autophagy remains unclear. The aim of this study was to investigate the regulatory mechanism of AS-Exo on neuronal autophagy. The mouse hippocampal neuronal cell line HT-22 was cultured in oxygen and glucose deprivation (OGD) condition to mimic ischemic injury. The primary astrocytes were used to isolate exosomes. Exosome labeling and uptake by HT-22 cells were observed by confocal laser microscopy. miR-190b expression was determined by qRT-PCR. HT-22 cell vitality and apoptosis were determined by CCK-8 assay and TUNEL staining, respectively. Levels of TNF-α, IL-6 and IL-1ß were analyzed by ELISA. Protein levels of apoptosis-related cleaved caspase-3, Bax, Bcl-2 and autophagy-related Beclin-1, LC3-I/II, Atg7, P62 were determined by western blot. A dual-luciferase reporter assay was performed to confirm the direct interaction between miR-190b and Atg7. miR-190b expression in AS-Exo was found to be significantly higher than that in AS. AS-Exo-mediated transfer of miR-190b attenuated OGD-induced neuronal apoptosis via suppressing autophagy. Moreover, Atg7 was identified as a target of miR-190b. AS-Exo-mediated transfer of miR-190b regulated autophagy by targeting Atg7. Collectively, our data indicated that AS-Exo transferred miR-190b to inhibit OGD-induced autophagy and neuronal apoptosis.