ABSTRACT
Objective:To evaluate the cerebral infarct volume and the nerve fiber connectivity between cortical and neurogenesis-related regions in the mouse model of reperfusion after middle cerebral artery occlusion (MCAO) by 11.7 Tesla(11.7 T) magnetic resonance imaging (MRI).Methods:MCAO models were established in SPF grade adult male C57BL/6 mice using the suture-occluded method.MRI scans were performed at 3 days before and 1 day after modeling.Infarct volumes were calculated, and nerve fiber tracking was performed on specific brain regions to analyze the nerve fiber number and the parameters of fractional anisotropy(FA), mean diffusivity(MD), axial diffusivity (AD)and radial diffusivity(RD). SPSS 26.0 was used for statistical analysis, and paired t test was used to compare the data before and after modeling. Results:(1) After MCAO-induced ischemia, the infarct volume was up to (35.11±17.57)mm 3, and the FA value of the infarct area was significantly reduced compared with that of before modeling( t=4.73, P<0.01). (2) At the anterior-posterior(AP): + 1.2 mm section, the results of fiber tracking showed that compared with before modeling, the number of fiber bundles originating from the dorsal horn of the lateral sub-ventricle zone(SVZ)to the cortex reduced ((92 584.20±14 751.00) vs (59 815.60±6 752.46), t=4.87, P<0.01), and the number of fiber bundles projected to the infarcted area reduced ((107 671.40±10 497.57) vs (61 658.60±10 178.21), t=6.43, P<0.01). FA, AD, MD, and RD values were all decreased in different degrees( t=3.38-6.43, all P<0.05). (3) At the AP: -3.8 mm section, the number of fiber bundles originating from the dorsal horn of the SVZ to the cortex decreased (after modeling(96 944.00±18 331.09), before modeling(58 767.80±16 445.25), t=2.99, P<0.05), and the values of FA, AD, MD and RD decreased after ischemia ( t=7.30, 5.05, 6.74, 4.13, all P<0.05). Conclusion:The ultra-high field strength of 11.7 T MRI can accurately detect the following results that the number of nerve fiber bundles from the SVZ to the cortex or infarct area are both significantly reduced, and diffusion tensor parameters are consistently changed in mice after 1 day of ischemia-reperfusion.
ABSTRACT
【Objective】 To investigate the protective effect and mechanism of platelet-rich plasma (PRP) on lipopolysaccharide (LPS) -induced inflammatory response in BV2 cells. 【Methods】 BV2 microglia were divided into normal control group, 10%PRP control group, LPS group (LPS induction), 3%PRP+ LPS group (LPS induction, 3%PRP pretreatment), 5%PRP+ LPS group (LPS induction, 5%PRP pretreatment), 10%PRP+ LPS group (LPS induction, 10%PRP pretreatment), and the proliferation of BV2 cells was measured by CCK-8. The mitochondrial membrane potential of BV2 cells was measured by confocal microscopy, ROS was measured by fluorescence method, and NO was measured by Griess method. The protein expressions of IL-6, TNF-α, BACH1, GPX4, NRF2 and HO-1 were detected by Western blot. In addition, BV2 microglia were treated with HO-1 inhibitor and divided into normal control group, LPS group, ZnPP+ LPS group, 10%PRP+ LPS group, ZnPP+ LPS+ 10%PRP group, and the protein expressions of HO-1, IL-6 and TNF-α were detected by Western blot. 【Results】 Compared with normal control group, PRP promoted the proliferation of BV2 cells (P<0.01). The mitochondrial membrane potential decreased, ROS production increased, the levels of NO, IL-6, TNF-α and BACH1 increased (P<0.01). However, the expression levels of GPX4, NRF2 and HO-1 decreased (P<0.01) in LPS group. Compared with LPS group, the proliferation activity and mitochondrial membrane potential of BV2 cells in 3%PRP+ LPS, 5%PRP+ LPS and 10%PRP+ LPS groups significantly increased. The levels of ROS, NO, IL-6, TNF-α and BACH1 significantly decreased (P<0.01). The expressions of GPX4, NRF2 and HO-1 in different concentrations of PRP (3%, 5% and 10%) increased (P<0.01). Moreover, the expression of IL-6 and TNF-α in ZnPP+ LPS group was significantly higher than that in LPS group after HO-1 inhibitor treatment. Compared with 10%PRP+ LPS+ ZnPP group, HO-1 inhibitor could reverse the effect of PRP on the expression of IL-6 and TNF-α in LPS-induced BV2 cells (P<0.01). 【Conclusion】 PRP inhibits the inflammatory response of BV2 microglia induced by LPS by activating the NRF2/HO-1 signaling pathway.
ABSTRACT
Objective To explore the effects of morroniside on the expression of CD34 in ipsilateral cortex of rats after focal cerebral isch-emia-reperfusion. Methods 45 male Sprague-Dawley rats were divided into sham group (n=9), ischemia group (n=9), and morroniside groups (low, medium and high dosage groups, n=9). The middle cerebral artery were occluded for 30 minutes, and reperfused. Morroniside was administered intragastrically once a day at dose of 30 mg/kg, 90 mg/kg, 270 mg/kg after operation. The expression of CD34 in the isch-emic ipsilateral cortex were detected with immunohistochemistry (n=6) and Western blotting (n=3) 7 days after operation. Results The ex-pression of CD34 increased in the ischemia group compared with the sham group, and further increased in the morroniside groups of high dos-age compared with the ischemia group (F>14.865, P<0.001). Conclusion Morroniside could increase the expression of CD34 in the ischemic ipsilateral cortex after ischemia-reperfusion in rats, which may promote the angiogenesis and neurogenesis after ischemia.
ABSTRACT
@#Objective To investigate the effects of morroniside on the expression of vascular endothelial growth factor (VEGF) and fi-broblast growth factor-2 (FGF-2) in rat cortex after focal cerebral ischemia-reperfusion. Methods 30 male Sprague-Dawley rats were ran-domly divided into sham group, model group, morroniside-low group (30 mg/kg), morroniside-middle group (90 mg/kg) and morroni-side-high group (270 mg/kg). Middle cerebral arteries of rats were occluded for 30 minutes with Longa's method and re-perfused. The ex-pression of VEGF and FGF-2 in the ischemic ipsilateral cortex was detected with Western blotting 7 days after reperfusion. Results The ex-pression of both VEGF and FGF-2 increased in the ischemic ipsilateral cortexin in all the ischemic groups compared with the sham group (P<0.05). The expression of VEGF further increased in a dose-dependent manner in all the morroniside groups compared with that of model group (P<0.05), and the expression of FGF-2 increased in the morroniside-high group (P<0.001). Conclusion Morroniside could increase the expression of VEGF and FGF-2 after ischemia-reperfusion, which might promote angiogenesis.