Tunable electronic and magnetic properties of defective g-ZnO monolayer doping with non-metallic elements.

CONTEXT: The electronic and magnetic properties of non-metallic (NM) elements doping defective graphene-like ZnO (g-ZnO) monolayer including O vacancy (VO) and Zn vacancy (VZn) are studied. The results show that VO-g-ZnO is a semiconductor and VZn-g-ZnO is a magnetic semiconductor. B, C, N, Si, P, 2S, and 2Si doping VO-g-ZnO systems present half-metal and magnetic semiconductors, and the magnetism mainly originates from the spin polarization of doping atoms. For single or double NM elements doping VZn-g-ZnO, 2P doping system presents a semiconductor, while other systems present ferromagnetic metal, half-metal, and magnetic semiconductor. The magnetism of single NM elements doping VZn-g-ZnO mainly comes from the spin polarization of O atoms near the defect point. For double NM elements doping VZn-g-ZnO, spin splitting occurs mainly in p orbitals of O atoms, dopant atoms, and d orbitals of Zn atoms. NM elements doping defect g-ZnO can effectively regulate the electronic and magnetic properties of the system. METHODS: The software package VASP 5.4.1 (Vienna ab initio Simulation Package) is used for calculations in this paper. The local density approximation (LDA) is adopted as an exchange and correlation function to perform the structural optimization and analysis of electronic structure and magnetic properties.

Targeting microbiota-immune-synaptic plasticity to explore the effect of tea polyphenols on improving memory in the aged type 2 diabetic rat model.

OBJECTIVES: The study aimed to explore whether TP could improve memory in the aged type 2 diabetic rat model by regulating microbiota-immune-synaptic plasticity axis. METHODS: The experiment was divided into two parts. Firstly, to investigate the effects of TP on the physiopathology of the aged T2DM model rats, rats were randomly divided into the Normal control group, the aged group, the Aged T2DM model group, the TP 75, 150, 300 mg/kg groups, the 150 mg/kg Piracetam group and the 3 mg/kg Rosiglitazone group. Then, to further verify whether TP improved memory in aged T2DM rat model by regulating intestinal flora, the fecal microbiota transplantation (FMT) from the rats in the 300 mg/kg TP group into the rats in the aged T2DM model group was carried out. Effects on gut microbiota, colonic integrity (epithelial tight junction proteins), and endotoxemia (serum LPS) were examined, along with synaptic structure, synaptic plasticity-related structural proteins and inflammation signaling of the hippocampus in our study. RESULTS: Our results demonstrated that TP alleviated memory impairments in the aged T2DM rat model. The specific outcomes were as follows: TP 300 mg/kg corrected the gut dysbacteriosis, alleviated intestinal permeability reduction and peripheral/central inflammation, inhibited the TLR4/NF-κB signaling pathway. Meanwhile, TP improved the synaptic plasticity in the hippocampus of the aged T2DM model rats, whose expressions of SYN, PSD 95, NMDAR1 and GluR1 in hippocampus were significantly up-regulated. Surprisingly, rats of the FMT group displayed the same changes. DISCUSSION: TP improves the memory in aged T2DM rat model. The mechanism may be related to the alteration of gut flora, which can inhibit hippocampal TLR4/NF-κB signaling to attenuate neuroinflammation, then improve synaptic plasticity. The study proposes that TP interventions aimed at manipulating the gut microbiota may hold great potential as an effective approach for preventing and treating this disease.

Mediation Effects of IL-1ß and IL-18 on the Association Between Vitamin D Levels and Mild Cognitive Impairment Among Chinese Older Adults: A Case-Control Study in Taiyuan, China.

Objective: Mild cognitive impairment (MCI) is a common, chronic, and complex disease in the elderly, which is often influenced by a variety of factors that include nutrition and inflammation. This study was undertaken to evaluate the mediation effects of inflammation on the association between vitamin D levels and MCI. Methods: We explored the associations of inflammation and cognitive impairment related to 25(OH)D3 deficiency among 360 older people from the communities in China. Demographic characteristics, lifestyle, and health status were investigated by questionnaire, cognitive function was detected by MoCA, and plasma 25(OH)D3, interleukin-1ß (IL-1ß), and interleukin-18 (IL-18) were measured by ELISA. Spearman's correlation analysis and logistic regression analysis were used to analyze the relationship among 25(OH)D3, IL-1ß, and IL-18 in the MCI group and the control group and further to analyze the relationship between 25(OH)D3 and inflammatory factors in the MCI group. Finally, mediation analysis was performed to evaluate whether inflammation mediated the effect of 25(OH)D3 deficiency on cognitive impairment. Results: There were lower plasma 25(OH)D3 concentration and higher IL-1ß and IL-18 levels in the MCI group compared with the controls. The levels of 25(OH)D3 were positively correlated with the MoCA scores and scores of different domains; the levels of IL-1ß and IL-18 were negatively correlated with them (p < 0.05). In multivariate logistic analysis, there were significant associations among 25(OH)D3, IL-1ß, IL-18, and MCI after adjusted. Further analysis revealed the significant association between the subjects with VD deficiency and the highest quartile of IL-18 in MCI (OR = 4.066), not with IL-1ß after adjusting the confounding variables in MCI group. Ultimately, mediation analysis suggested that IL-1ß and IL-18 could explain 25.4 and 17.5% of effect of the risk of cognitive impairment related to 25(OH)D3 deficiency. Conclusion: Our findings suggested that 25(OH)D3 deficiency could increase the risk of cognitive impairment by a mechanism partly involving inflammation. Therefore, vitamin D supplementation may improve or delay the decline in cognitive function caused by inflammation in the elderly.

Combination of tea polyphenols and proanthocyanidins prevents menopause-related memory decline in rats via increased hippocampal synaptic plasticity by inhibiting p38 MAPK and TNF-α pathway.

OBJECTIVE: Many studies have examined the beneficial effects of tea polyphenols (TP) and proanthocyanidins (PC) on the memory impairment in different animal models. However, the combined effects of them on synaptic, memory dysfunction and molecular mechanisms have been poorly studied, especially in the menopause-related memory decline in rats. METHODS: In this rat study, TP and PC were used to investigate their protective effects on memory decline caused by inflammation. We characterized the learning and memory abilities, synaptic plasticity, AMPAR, phosphorylation of the p38 protein, TNF-ɑ, structural synaptic plasticity-related indicators in the hippocampus. RESULTS: The results showed that deficits of learning and memory in OVX + D-gal rats, which was accompanied by dendrites and synaptic morphology damage, and increased expression of Aß1-42 and inflammation. The beneficial effects of TP and PC treatment were found to prevent memory loss and significantly improve synaptic structure and functional plasticity. TP+PC combination shows more obvious advantages than intervention alone. TP and PC treatment improved behavioral performance, the hippocampal LTP damage and the shape and number of dendrites, dendritic spines and synapses, reduced the burden of Aß and decreased the inflammation in hippocampus. In addition, TP and PC treatment decreased the expressions of Iba-1, TNF-α, TNFR1, and TRAF2. CONCLUSIONS: These results provided a novel evidence TP combined with PC inhibits p38 MAPK pathway, suppresses the inflammation in hippocampus, and increase the externalization of AMPAR, which may be one of the mechanisms to improve synaptic plasticity and memory in the menopause-related memory decline rats.

Tea polyphenols ameliorates memory decline in aging model rats by inhibiting brain TLR4/NF-κB inflammatory signaling pathway caused by intestinal flora dysbiosis.

AIMS: Tea is a rich source of pharmacologically active molecules that has been suggested to provide a variety of health benefits. However, its mechanism of action in aging-related intestinal flora dysbiosis mediated neuroinflammation is still unclear. This study aimed to explore whether tea polyphenols (TP) can improve memory by regulating intestinal flora mediated neuroinflammation in aging model rats. METHODS: Ovariectomy (OVX) combined with D-galactose injection was used to establish aging rats related to menopause. The rats were divided into Sham control group, Aging model group, TP 75 mg/kg, 150 mg/kg, 300 mg/kg groups and VE group. After 12 weeks of intervention, the shuttle box test and Y maze test were used to check the memory of rats. The composition of intestinal flora was assessed by 16S rRNA sequencing technology. HE staining and ELISA were used to detect intestinal epithelial morphology and permeability, respectively. TLR4/NF-κB inflammation pathway related indicators were investigated by western blot, and the microglia activation in rat hippocampal tissue was checked by immunofluorescence. RESULTS: In the shuttle box test and the Y maze test, compared with the Sham control group, the memory of Aging model rats was significantly declined. It was observed that the intestinal flora of Aging model rats was dysbiosis, the permeability of the intestinal epithelium was increased. Further experimental results showed that the expression of TLR4/NF-κB inflammatory pathway related proteins in the hippocampus were increased, and the excessive activation of microglia was observed. The beneficial effects of TP intervention have been found to prevent memory decline and significantly improve brain inflammation induced by intestinal flora dysbiosis, and TP 300 mg/kg showed a more obvious advantage than TP 75 mg/kg. TP 300 mg/kg can significantly improve the behavior of rats, improve the composition and diversity of the intestinal flora, and the shape and function of the intestinal epithelium. By reversing the increased expression levels of TLR4, IRAK, p-IκBα and nuclear NF-κB p65 proteins in the hippocampus of Aging model rats, the activation of microglia in the CA1, CA3 and Dentate gyrus (DG) sub-regions of the hippocampus can be inhibited. CONCLUSION: TP inhibits the brain TLR4/NF-κB inflammatory signal pathway caused by the dysbiosis of intestinal flora, which may be one of the mechanisms to improve the memory decline in aging model rats.

[Protective effect of 1, 25(OH)_2D_3 on Aß_(1-42)-induced pyrolysis in PC12 cells].

OBJECTIVE: To investigate the protective effect of 1, 25(OH)_2D_3 on Aß_(1-42)-induced pyrolysis in PC12 cells. METHODS: The Alzheimer& apos; s disease model in PC12 cells was established with 20 µmol/L Aß_(1-42). The experiment was divided into control group, model group(20 µmol/L Aß_(1-42)) and 1, 25(OH)_2D_3 groups(1, 10, 100 nmol/L 1, 25(OH)_2D_3+20 µmol/L Aß_(1-42)). Cell activity was detected by CCK-8, cell membrane permeability was detected by AO/EB staining, lactic dehydrogenase(LDH)and interleukin-1ß(IL-1ß)were detected by colorimetry and ELISA, NOD-like receptor family protein 1(NLRP1), cysteinyl aspartate specific proteinase-1(caspase-1)and gasdermin D(GSDMD)protein expression were detected by Western Blot. RESULTS: Compared with the control group, the cell activitywas significantly decreased(P& lt; 0. 01), cell membrane permeability, the level of LDH and IL-1ß, and the expression of NLRP1, caspase-1 and GSDMD were significantly increased(P& lt; 0. 01). Compared with the model group, the cell activity was significantly increased(P& lt; 0. 01), cell membrane damage was decreased in PC12 cells exposed to 1, 25(OH)_2D_3. The level of LDH and IL-1ß were significantly decreased(P& lt; 0. 01) in PC12 cells exposed to 10 and 100 nmol/L 1, 25(OH)_2D_3. The expression of NLRP1 and GSDMD in 1 nmol/L 1, 25(OH)_2D_3 group was decreased(P& lt; 0. 05), and the decrease was more significant in 10 and 100 nmol/L 1, 25(OH)_2D_3 groups(P& lt; 0. 01). The expression of caspase-1 was significantly decreased in 10 and 100 nmol/L 1, 25(OH)_2D_3 groups(P& lt; 0. 05, P& lt; 0. 01). CONCLUSION: 1, 25(OH)_2D_3 exerts a significant protective effect against Aß_(1-42)-induced PC12 cells injury through inhibition of neuronal pyrolysis.

[Effects of resveratrol combined with soy isoflavones on apoptosis induced by oxidative stress in hippocampus of aging model rats].

OBJECTIVE: To investigate the effect of resveratrol(Res) combined with soy isoflavones(SIF) on apoptosisinduced by oxidative stress in hippocampus in aging model rats. METHODS: Sixty female SD rats were randomly divided into the Sham control group, aging model group, Res treatment group, SIF treatment group, Res combined with SIF treatment group and estrogen replacement therapy group(ERT group). Rats with aging were induced by bilateral ovariectomy combined with intraperitoneal injection of D-galactose. TUNEL and transmission electron microscopy were used to observe apoptosis and ultrastructural changes of mitochondrion in hippocampus, respectively. The activities of superoxide dismutase(SOD), catalase(CAT), glutathione peroxidase(GSH-Px) and content of Malonaldehyde(MDA) were detected in the hippocampal homogenate. The protein expressions of cytochrome C oxidase(COX) Ⅰ, Bcl-2 associated X protein(Bax)、B-cell leukemia/lymphoma 2(Bcl-2) and cytochrome C were detected by Western blot. RESULTS: Compared with the Sham control group, the number of TUNEL-positive cells and the apoptotic index(AI) in the model group increased. Marked increase of mitochondrial swelling and vacuolation, decrease of mitochondrial integrity were also observed in the model group. Additionally, the levels of SOD, CAT and GSH-Px were decreased and the level of MDA was increased in the model group in the hippocampus, Bax and cytochrome C protein expression increased, and the COX Ⅰ protein expression and the ratio of Bcl-2/Bax decreased(P<0. 05). In compared with the model group, the number of TUNEL-positive cells and AI significantly decreased, mitochondrial integrity improved in all of the treatment groups, the COX Ⅰ protein expression significantly up-regulated, Bax and cytochrome C protein expression down-regulated, and the protein expression ratio of Bcl-2/Bax increased(P<0. 05 or P<0. 01). Compared with the Res alone and SIF alone treatment group, Res combined SIF treatment decreased the AI and Bax, cytochrome C protein expression, moreover, increased the mitochondrial integrity rate, COX Ⅰ and Bcl-2/Bax protein expression ratio(P<0. 05). There was no statistically significant difference in Bcl-2 protein expression among all the groups(P>0. 05). CONCLUSION: Res and SIF alone and in combination decreased apoptosisinduced by oxidative stress in hippocampus of aging model rats, and beneficial effect in the Res combined SIF treatment group is more significant than that in the alone administration. Improving the antioxidant capacity, increasing the protein expressions of COX Ⅰ andthe ratio of Bcl-2 and Bax, and inhibiting the release of cytochrome C may be the mechanisms by which Res and SIF improve apoptosis in aging rats.