Objective To investigate the effects of high-calorie diet and age on brain function of ApoE-/-mice.Methods A total of 20 adult ApoE mice(8 months old)and elderly ApoE-/-mice(18 months old)were randomly divided into normal diet adult group,normal diet elderly group,high-calorie diet adult group,and high-calorie diet elderly group,with 5 animals in each group.The mice were fed with corresponding standard diet and high-fat diet for 8 weeks.Their body mass was monitored,and blood glucose was detected with glucose tolerance test.The relative contents of NAA and Cho in the hippocampus and hypothalamus were detected by Magnetic resonance spectroscopy.Y-Maze and open field tests were performed to detect cognitive function,and West-ern blotting was applied to detect the expression of synaptic associated protein 25(SNAP-25),synaptophysin,postsynaptic dense protein-95(PSD-95),iNOS and IL-1β.Results Compared with the normal diet adult group,the NAA content in the hippocampus,Cho and NAA contents in the hypothalamus,spontaneous alternation rate,and expression levels of SNAP-25,synaptophysin and PSD-95 in brain tissue(P＜0.05,P＜0.01)were decreased,and the expression of iNOS and IL-1β(P＜0.01)was increased in the high-calorie diet adult group.The normal diet elderly group had reduced contents of NAA in the hippocampus and Cho in the hypothalamus,and expression levels of SNAP-25,synaptophysin and PSD-95(P＜0.05,P＜0.01),and elevated expression of iNOS and IL-1β(P＜0.01)when compared with the normal diet adult group.Compared with the normal diet elderly group,high-calorie diet resulted in decreased Cho and NAA in both hippocampus and hy-pothalamus,central distance/total distance and down-regulation of SNAP-25,synaptophysin and PSD-95(P＜0.05,P＜0.01),and enhanced expression of iNOS and IL-1β(P＜0.01)in the elderly mice.Compared with the high-calorie diet adult group,the high-calorie diet elderly group had reduced NAA in hippocampus,central distance/total distance and average speed,and decreased expression of synaptophysin(P＜0.05,P＜0.01),and increased expression of iNOS and IL-1β(1.61±0.10 vs 1.35±0.13,2.04±0.08 vs 1.54±0.11,P＜0.05,P＜0.01).Conclusion High-calorie diet results in metabolic disorders and neuroinflammation,inhibits the expression of syn-aptic proteins,and thus leads to cognitive dysfunction in ApoE mice.Long-term high-calorie diet and ageing promote the decline of brain function in ApoE mice.

Objective:To investigate the role and mechanism of astrocyte (AS) derived exosomes in protecting brain microvascular endothelial cells (bEnd. 3) from cerebral ischemia reperfusion injury by establishing an oxygen-glucose deprivation/re-oxygenation (OGD/R) model in vitro. Methods:(1) Dual-luciferase reporter gene assay was used to confirm the regulating effect of miR-193b-3p on transient receptor potential cation channel, subfamily M, member 2 (TRPM2). OGD/R model was established by OGD 8 h followed by reoxygenation 24 h in bEnd. 3 cells after being transfected miR-193b-3p mimics/negative sequence (OGD/R+miR-193b-3p mimics group or OGD/R+miR-193b-3p negative sequence group); real-time quantitative PCR (RT-qPCR) was used to detect the miR-193b-3p expression, Western blotting (WB) was used to detect the expressions of TRPM2, cleaved caspase-3, Bax, Bcl-2, ZO-1 and Claudin-5, and flow cytometry was used to detect the apoptosis. (2) AS was extracted from the cerebral cortex of C57BL/6 suckling mice and identified; modeling time was determined by CCK-8 and AS-derived exosomes were extracted by ultracentrifugation from cell supernatant and identified by electron microscopy, particle size analysis, and WB for marker proteins. RT-qPCR was used to detect the miR-193b-3p expression in AS and AS-derived exosomes. Low-expressed miR-193b-3p exosomes were extracted from AS after being transfected miR-193b-3p inhibitory sequence and co-incubated with OGD/R bEnd. 3 cells (group of OGD/R+AS-derived inhibitory sequence exosomes); exosomes were extracted from AS transfecting with miR-193b-3p negative sequence, and co-incubated with OGD/R bEnd.3 cells (group of OGD/R+AS-derived negative sequence exosomes); and normal exosomes were co-incubated with OGD/R bEnd. 3 cells (group of OGD/R+AS-derived exosomes). The miR-193b-3p expression in these 3 groups was detected by RT-qPCR, expressions of TRPM2, cleaved-caspase-3, Bax, Bcl-2, ZO-1, and Claudin-5 were detected by WB, cell apoptosis was detected by flow cytometry, and cell migration ability was detected by scratch test.Results:(1) Dual-luciferase reporter gene assay showed that miR-193b-3p could bind to TRPM2 mRNA. The miR-193b-3p can improve the TRPM2-mediated apoptosis and tight junction reduction in bEnd.3 cells during OGD/R: compared with OGD/R group, OGD/R+miR-193b-3p mimics group had significantly decreased TRPM2, cleaved-caspase-3, and Bax protein expressions, and statistically increased Bcl-2, ZO-1 and Claudin-5 protein expressions ( P<0.05). Flow cytometry further verified the above results: compared with OGD/R group, OGD/R+miR-193b-3p mimics group had significantly decreased cell apoptosis rate (21.34% vs. 13.93%, P<0.05). (2) The extracted exosomes exhibited lipid bilayer cup-like structure with particle size of 126.5 nm (exosome marker proteins: negative Cal and positive CD81 and SG101), indicating successful exosome extraction. After modeling, miR-193b-3p expression in AS and AS-derived exosomes was significantly decreased compared with that in the Control goup ( P<0.05). Compared with the OGD/R group, the group of OGD/R+AS-derived exosomes and group of OGD/R+AS-derived negative sequence exosomes had significantly increased miR-193b-3p expression, statistically decreased TRPM2, cleaved-caspase-3 and Bax protein expressions, and significantly increased ZO-1, Claudin-5 and Bcl-2 expressions ( P<0.05); while compared with those in the OGD/R group, no significant changes in the above protein expressions in group of OGD/R+AS-derived inhibitory sequence exosomes were noted ( P>0.05). Compared with the OGD/R group (18.22%), group of OGD/R+AS-derived exosomes and group of OGD/R+AS-derived negative sequence exosomes had significantly decreased apoptosis rate (14.09% and 13.79%, P<0.05), while group of OGD/R+AS-derived inhibitory sequence exosomes had no significant change (18.41%, P>0.05). Compared with the OGD/R group (13.55%), group of OGD/R+AS-derived exosomes and group of OGD/R+AS-derived negative sequence exosomes had significantly increased migration ability (43.01% and 40.59%, P<0.05), while group of OGD/R+AS-derived inhibitory sequence exosomes had no significant change (16.26%, P>0.05). Conclusion:AS-derived exosomes can suppress TRPM2 protein expression in brain microvascular endothelial cells distantly by miR-193b-3p to improve the brain microvascular endothelial cell injury caused by OGD/R, and then improve OGD/R injury.

ObjectiveTo study the effect of Wulingsan on cerebral edema after intracerebral hemorrhage （ICH） in mice and explore the treatment mechanism. MethodsThe mouse model of ICH was established by injection of collagenase into the caudate nucleus. Mice were randomly assigned into the following groups： sham， ICH， intervention before modeling with low-dose and high-dose （3.69， 11.07 g·kg^-1， respectively） Wulingsan， and intervention after modeling with high-dose Wulingsan. The modified neurological severity score （mNSS） was recorded， and the small animal MRI T2 sequential scanning was performed to measure the volume of cerebral hemorrhage after the modeling of ICH in each group. The Y-maze test， open field test， and Morris water maze test were conducted to evaluate the neurological behaviors of mice in each group. Hematoxylin-eosin staining was employed to observe the pathological changes in the brain tissue. Immunohistochemistry was employed to observe the expression of aquaporin 4 （AQP4）， neuronal nuclei （NeuN）， and glial fibrillary acidic protein （GFAP） in the brain tissue. Western blot was employed to determine the protein levels of AQP4， Claudin-5， and zonula occludens-1 （ZO-1） in the hematoma area. ResultsCompared with the sham group， the ICH group showed increases in the mNSS， the cerebral hemorrhage volume， and the escape latency in the Morris water maze test （P<0.01）， decreases in the times of touching the platform and times of entering the quadrant where the platform was located in the Morris water maze test， and reductions in the spontaneous alternation rate in the Y-maze test and the ratio of distance of center travel to total travel distance in the open field test （P<0.01）. Moreover， pathological changes such as cell disarrangement， cell space enlargement， and cell swelling were observed in the ICH group. Immunohistochemistry results showed that the ICH group had higher proportions of AQP4- and GFAP-positive cells and lower proportion of NeuN-positive cells than the sham group （P<0.01）. Compared with the sham group， the ICH group showed an up-regulated protein level of AQP4 and down-regulated protein levels of Claudin-5 and ZO-1 （P<0.01）. Compared with the ICH group， the intervention with Wulingsan decreased the mNSS， the volume of cerebral hemorrhage， and the escape latency in the Morris water maze test （P<0.05， P<0.01）， while increasing the times of touching the platform and times of entering the quadrant where the platform was located in the Morris water maze test， the spontaneous alternation rate in the Y-maze test， and the ratio of distance of center travel to total travel distance in the open field test （P<0.05， P<0.01）. Furthermore， the intervention with Wulingsan alleviated the pathological changes in the brain tissue after ICH， decreased the proportion of AQP4- and GFAP-positive cells （P<0.01）， increased the proportion of NeuN-positive cells （P<0.01）， down-regulated the protein level of AQP4 （P<0.01）， and up-regulated the protein levels of Claudin-5 and ZO-1 （P<0.01）. ConclusionThe intervention with Wulingsan could reduce the neural function score and the cerebral hemorrhage volume， up-regulate the expression of Claudin-5 and ZO-1， and down-regulate the expression of AQP4 to ameliorate the neurological function defect and cerebral edema after ICH， thereby protecting the brain.