RESUMEN
Acute hypobaric hypoxic brain damage is a potentially fatal high-altitude sickness. Autophagy plays a critical role in ischemic brain injury, but its role in hypobaric hypoxia (HH) remains unknown. Here we used an HH chamber to demonstrate that acute HH exposure impairs autophagic activity in both the early and late stages of the mouse brain, and is partially responsible for HH-induced oxidative stress, neuronal loss, and brain damage. The autophagic agonist rapamycin only promotes the initiation of autophagy. By proteome analysis, a screen showed that protein dynamin2 (DNM2) potentially regulates autophagic flux. Overexpression of DNM2 significantly increased the formation of autolysosomes, thus maintaining autophagic flux in combination with rapamycin. Furthermore, the enhancement of autophagic activity attenuated oxidative stress and neurological deficits after HH exposure. These results contribute to evidence supporting the conclusion that DNM2-mediated autophagic flux represents a new therapeutic target in HH-induced brain damage.
Asunto(s)
Ratones , Animales , Hipoxia , Estrés Oxidativo , Autofagia , Cognición , Sirolimus/uso terapéuticoRESUMEN
Objective:To analyze the hemodynamic changes of different types of unruptured intracranial aneurysms before and after flow diverter (FD) treatment with computational fluid dynamics (CFD), and lay research foundation for precision treatment and prognosis evaluation for unruptured intracranial aneurysms.Methods:Four patients with different types of unruptured intracranial aneurysms, admitted to Department of Neurosurgery, First Affiliated Hospital of Air Force Medical University from January 2022 to March 2022, were chosen. Digital subtraction angiography (DSA) data of the patients before and immediately after surgery were collected. Morphological and hemodynamic parameters of the aneurysms were calculated by 3D reconstruction, finite element simulation, and CFD methods: ostium ratio (OsR), neck ratio (NR), area ratio (ArR), volume ratio (VoR), wall shear stress (WSS), normalized wall shell stress (NWSS), blood inflow, relative inflow, aneurysm average velocity, parent artery average velocity, normalized velocity, residual flow volume (RFV), and inflow concentration index (ICI); differences of these indexes before and after treatment were compared.Results:The OsR of 6 aneurysms was 0.225, 0.267, 0.265, 0.389, 1.000, 1.000, respectively; NR was 1.220, 0.274, 1.090, 1.587, 2.809, and 4.019, respectively; ArR was 0.608 and 0.224, 0.623, 3.462, 1.225 and 1.784, respectively; and VoR was 0.386, 0.052, 0.212, 3.462, 0.422 and 1.882, respectively. The parameters of WSS, NWSS, blood inflow, relative inflow, aneurysm average velocity, parent artery average velocity, normalized velocity, RFV, and ICI decreased obviously after FD implantation.Conclusion:On the basis of 3D reconstruction combined with FD/coil virtual implantation, CFD-based hemodynamic analysis can obtain accurate parameters of different types of intracranial aneurysms before and after FD treatment.
RESUMEN
Objective:To investigate the influence and mechanism of stromal interaction molecule 1 (STIM1) in microglia/macrophages M1 activation after cerebral ischemia-reperfusion injury.Methods:(1) Animal experiment: 20 male C57BL/6J mice were randomly divided into sham-operated (Sham) group, middle cerebral artery occlusion and reperfusion (MCAO/R) group, MCAO/R+si-Ctrl group, and MCAO/R+si-STIM1 group ( n=5); MCAO/R models were established in mice of the latter 3 groups; empty vector control virus and STIM1 gene knockout lentivirus were transfected into mice in the MCAO/R+si-Ctrl group and MCAO/R+si-STIM1 group. The transfection efficiency of STIM1 and the expression of microglia/macrophages M1 activation marker cluster of differentiation 86 (CD86) in each group were observed. (2) Cell experiment: primary microglia were divided into Ctrl group, oxygen-glucose deprivation/re-oxygenation (OGD/R) group, OGD/R+si-Ctrl group, OGD/R+si-STIM1 group, OGD/R+solvent group, and OGD/R+4-phenylbutyric acid (4-PBA) group; OGD/R models were established in the later 5 groups; empty vector control virus and STIM1 gene knockout lentivirus were transfected into mice in the OGD/R+si-Ctrl group and OGD/R+si-STIM1 group; cells in the OGD/R+4-PBA group were pre-treated with 1 mmol/L 4-PBA for 1 h at 24 h before OGD/R modelling to inhibit endoplasmic reticulum stress (ERS), and cells in the OGD/R+solvent group were pre-treated with 0.5% dimethyl sulfoxide (DMSO) for 1 h at the same time. Reverse transcription quantitative polymerase chain reaction (RT-qPCR), ELISA, Western blotting and other methods were used to detect the levels of CD86, tumour necrosis factor-α ( TNF-α) mRNA, interleukin (IL)-1β, and ERS-related proteins (transcription factor C/EBP homologous protein [CHOP], activated transcription factor 4 [ATF4]) in these cells. Results:(1) Animal experiment: the STIM1 expression in MCAO/R+si-STIM1 group was significantly lower than that in Sham group, MACO/R group and MCAO/R+si-Ctrl group ( P<0.05); as compared with that in the MACO/R group and MCAO/R+si-Ctrl group, the number of microglia/macrophages co-expressing CD86 and Iba-1 around the ischemic foci of mice in the MCAO/R+si-STIM1 group was significantly decreased ( P<0.05). (2) Cell experiment: as compared with those in the OGD/R group and OGD/R+si-Ctrl group, the expression levels of STIM1, CD86, and TNF-α mRNA, and supernatant IL-1β content in the OGD/R+si-STIM1 group were significantly decreased ( P<0.05); as compared with those in the OGD/R group and OGD/R+si-CTRL group, the ATF4 and CHOP expression levels in OGD/R+si-STIM1 group were significantly decreased ( P<0.05); as compared with those in the OGD/R group and OGD/R+solvent group, the CD86 level, TNF-α mRNA expression level and IL-1β content in the OGD/R+4-PBA group were significantly decreased ( P<0.05). Conclusion:STIM1 affects microglia/macrophages M1 activation after ischemia-reperfusion injury by regulating ERS level.