Lactobacillus plantarum AR113 attenuates liver injury in D-galactose-induced aging mice via the inhibition of oxidative stress and endoplasmic reticulum stress

Probiotics could effectively eliminate excess reactive oxygen species(ROS)generated during aging or lipid metabolism disorders,but their mechanism is unclear.The major purpose of this study was to investigate the mechanism of Lactiplantibacillus plantarun AR113 alleviating oxidative stress injury in the D-galactose induced aging mice.The result showed that pretreatment with L.plantarun AR113 significantly relieving H_(2)O_(2)induced cytotoxicity in HepG2 cells by maintain cell membrane integrity and increasing antioxidant enzyme activities.In D-galactose induced aging mice,L.plantarun AR113 could significantly attenuate liver damage and inflammatory infiltration by promoting endogenous glutathione(GSH)synthesis and activating the Nrf2/Keap1 signaling pathway in mice,and increasing the expression of regulated phaseⅡdetoxification enzymes and antioxidant enzymes.Further analysis shown that gavage of L.plantarun AR113 could significantly reduce the expression of G protein-coupled receptor 78(GPR78)and C/EBP homologous protein(CHOP)proteins,and promote the restoration of endoplasmic reticulum(ER)homeostasis,thereby activating cell anti-apoptotic pathways.These results were also confirmed in H_(2)O_(2)-treated HepG2 experiments.It indicated that L.plantarun AR113 could inhibit D-galactose-induced liver injury through dual inhibition of ER stress and oxidative stress.L.plantarun AR113 have good application potential in anti-aging and alleviating metabolic disorders.

Protective Role of Salidroside against Aging in A Mouse Model Induced by D-galactose

Objective To investigate the protective effects of putative AGEs （advanced glycation endproducts） inhibitor salidroside against aging in an accelerated mouse aging model induced by D-galactose. Methods A group of 5-month-old C57BL/6J mice were treated daily with D-galactose, D-galactose combined with salidroside, salidroside alone, and control buffer for 8 weeks. At the end of the treatment, serum AGEs levels, neurological activities, expression of glial fibrillary acidic protein （GFAP） and neurotrophin-3 （NT-3） in the cerebral cortex, as well as lymphocyte proliferation and IL-2 production were determined. Results D-galactose induced mouse aging model was developed as described before. As expected, salidroside blocked D-galactose induced increase of serum AGEs levels. It also reversed D-galactose induced aging effects in neural and immune system, as evidenced by improving motor activity, increasing memory latency time, and enhancing lymphocyte mitogenesis and interleukin-2 （IL-2） production. Furthermore, elevated expression of GFAP and NT-3 in the aged model mice was also reduced upon salidroside treatment. Conclusion Salidroside inhibits AGEs formation in vivo, which at least partially contributes to its anti-aging effect in D-galactose induced aging model.

PROTECTIVE EFFECT OF TETRAMETHYLPYRAZINE ON LEARNING AND MEMORY FUNCTION IN D-GALACTOSE-LESIONED MICE

To explore the protective effect of tetramethylpyrazine (TMP) on the learning and memory function in D-galactose (D-gal)-lesioned mice. Methods C57BL/6 mice were injected (s.c.) 2% D-gal for 40 days (100 mg·kg-1·d-1). Normal saline, TMP, and Huper-zine A were respectively given by intragastric administration in different groups from the third week. Learning and memory ability was tested with Morris water maze for 5 days at the sixth week. After completion of behavioral test, the mice were sacrificed by decapitation. The brain was rapidly removed, and the cortex and hippocampus were separated. The superoxide dismutase (SOD) activity and malondialdehyde (MDA) content in the cortex were determined. At the same time, the activity of choline acetyltransferase (ChAT) and acetylcholinesterase (AChE), the binding sites (Bmax) and the affinity (KD) of M-cholinergic receptor in the cortex, and Bmax and KD of N-methyl-D-aspartate (NMDA) receptor in the hippocampus were determined. Results In this model group, (1) The deficit of learning and memory ability, (2) elevated MDA content and lowered SOD activity, (3) decreased AChE activity and M-cholinergic receptor binding sites in the cortex, and (4) lowered NMDA receptor binding sites were observed in the hippocampus, as compared with the normal control. TMP could markedly (1) attenuate cognitive dysfunction, (2) lower MDA content and elevate SOD activity, (3) increase the activity of ChAT and AChE, and M-cholinergic receptor binding sites in the cortex in the mice treated with D-gal. NMDA receptor binding sites were also increased in the hippocampus in the treated mice. Conclusion TMP can significantly strengthen antioxidative function, improve central cholinergic system function, protect NMDA receptor activity, and thus enhance the learning and memory ability in D-gal-lesioned mice.

Inhibiting Effects of Achyranthes Bidentata Polysaccharide and Lycium Barbarum Polysaccharide on Nonenzyme Glycation in D-galactose Induced Mouse Aging Model

Objective To investigate the inhibiting effects and mechanism of achyranthes bidentata polysaccharide (ABP) and lycium barbarum polysaccharide (LBP) on nonenzyme glycation in D-galactose induced mouse aging model. Methods Serum AGE levels were determined by AGE-ELISA, MTT method was used to determine lymphocyte proliferation, IL-2 activity was determined by a bioassay method. Spontaneous motor activity was used to detect mouse's neuromuscular movement, latency of step-through method was used to examine learning and memory abilities of mouse, colormetric assay was used to determine hydroxyproline concentration in mouse skin, pyrogallol autoxidation method was used to determine superoxide dismutase (SOD) activity of erythrocytes. Results Decreased levels of serum AGE, hydroxyproline concentration in mouse skin and spontaneous motor activity in D-galactose mouse aging model were detected after treated with ABP or LBP, while lymphocyte proliferation and IL-2 activity, learning and memory abilities, SOD activity of erythrocytes, were enhanced. Conclusions ABP and LBP could inhibit nonenzyme glycation in D-galactose induced mouse aging model in vivo and ABP has a better inhibiting effect than LBP.

Antioxidant effect of Lactobacillus fermentum HFY02-fermented soy milk on D-galactose-induced aging mouse model

This study aimed to investigate the antioxidant effect of soybean milk fermented by a new type of Lactobacillus fermentum(LF-HFY02)by using D-galactose induced aging mice model.Firstly,the optimal fermentation conditions was screened out by detecting the effects of different fermentation temperature and time on the active components and antioxidant activity of soybean milk in viro.And then unfermented soybean milk and the soybean milk fermented by different Lactobacillus was given by gavage to D-galactose-induced aging mouse.The activities of GSH,GSH-Px,SOD,CAT and T-AOC in serum,brain and liver of soybean milk fermented by LF-HFY02 were significantly increased,while the content of MDA and the level of AGEs in hippocampal were significantly decreased compared with D-galactose induced group.Further more,the mRNA expression of GSH and SOD in mouse liver were obviously up-regulated by soybean milk fermented by LF-HFY02.The skin tissue structure of mice in the LF-HFY02 fermented soybean milk group was more complete,the collagen fibers were increased and arranged orderly and liver inflammation has improved compared with the model group.And Western blot analysis showed that LF-HFY02 effectively upregulated EGFR,SOD and GSH protein expression in mouse liver.These findings suggest that LF-HFY02 can effectively prevent D-galactose-induced oxidation and aging in mice,and the effect was even better than that of the Lactobacillus delbruechii subsp.bulgaricus and vitamin C.Thus,LF-HFY02 may be potentially employed as a probiotic strain.In conclusion,soybean milk fermented by LF-HFY02 can increase the content of antioxidant factors and the activity of antioxidant enzymes by regulating gene and protein expression,and finally inhibit the process of tissue cell peroxidation,and improve the oxidative damage of mouse skin and liver.The results could provide a basis for the research and development and industrial production of probiotic-related fermented soybean milk products.

Structural and Functional Changes of Immune System in Aging Mouse Induced by D-Galactose

Objective To investigate the role of D-galactose, especially in the structural and functional changes of the immune system in aging. Methods Serum levels of advanced glycation end-products （AGE） were determined by ELISA method. Ultra-structures of thymus and spleen were detected by transmission electron microscopy. MTT method was used to determine the lymphocyte proliferation. IL-2 activity was determined by bioassay. Northern blot was used to detect the IL-2 mRNA levels. Results Serum AGE levels of D-galactose- （P〈0.01） and AGE-treated （P〈0.05） mice （n=8） were increased significantly. The ultra-structures of thymus and spleen in D-galactose- and AGE-treated mice showed regressive changes similar to those in the aged control group. The lymphocyte mitogenesis and IL-2 activity of spleen were also decreased significantly （P〈0.01, n=8）. The change of IL-2 activity shown by Northern blot resulted from the change of mRNA expression. The AGE plus aminoguanidine group, however, showed no significant change in these parameters in comparison with the young control group （P〈0.01 or P〈0.05, n=8）. Conclusion D-galactose and AGE lead to a mimic regression change of aging in the immune system in vivo.

Ginkgo biloba leaf extract improves the cognitive abilities of rats with D-galactose induced dementia

Standardized Ginkgo biloba leaf extract has been used in clinical trials for its beneficial effects on brain func- tions, particularly in dementia. Substantial experimental evidences indicated that Ginkgo biloba leaf extract （EGB） protected neuronal cells from a variety of insults. We investigated the effect of EGB on cognitive ability and protein kinase B （PKB） activity in hippocampal neuronal cells of dementia model rats. Rats received an intra- peritoneal injection of D-galactose to induce dementia. Forty-eight Spraque-Dawley rats were randomly divided into six groups, including the control group, D-galactose group （Gal）, low-dose EGB group （EGB-L）, mid-dose EGB group （EGB-M）, high-dose EGB group （EGB-H） and treatment group. The EGB-L, EGB-M and EGB-H groups were administered with EGB and D-galactose simultaneously. Y-maze, cresyl violet staining, TUNEL assays and immunohistochemistry staining were performed to detect learning and memory abilities, morpho- logical changes in the hippocampus, neuronal apoptosis and the expressing level of phospho-PKB, respectively. Rats in the Gal group showed decreased abilities of learning and memory, and hippocampal pyramidal cell layer was damaged, while EGB administration improved learning and memory abilities. The Gal group exhibited many stained, condensed nuclei and micronuclei, either isolated or within the cytoplasm of cells （39.5 ± 1.4）. Apoptotic cells decreased in the groups of EGB-L （35.9±0.9）, EGB-M （16.8± 1.0） and EGB-H （10.1±0.8）, and there were statistical significances compared with the Gal group. Immunoreactivity of phospho-PKB was localized diffusely throughout the cytosol of cells in all groups, while the immunoreactivity of the Gal group was weak. EGB signifi- cantly attenuated learning and memory impairment in a dose-dependent manner, while it could decrease the nmber of TUNEL-positive cells, and increase the activity of PKB. Our results demonstrated that EGB attenuated memory impairment and cell apoptosis in galactose-induced dementia model rats by activating PKB.

Effect of Schisandra chinensis polysaccharide on intracerebral acetylcholinesterase and monoamine neurotransmitters in a D-galactose-induced aging brain mouse model

BACKGROUND： The most prominent characteristic of brain aging is decreased learning and memory ability. The functions of learning and memory are closely related to intracerebral acetylcholinesterase （ACHE） and monoamine neurotransmitter activity. Previous studies have shown that Schisandra chinensis polysaccharide has an anti-aging effect. OBJECTIVE： To explore the effects of Schisandra chinensis polysaccharide on AChE activity and monoamine neurotransmitter content, as well as learning and memory ability in a D-galactose-induced aging mouse brain model compared with the positive control drug Kangnaoling. DESIGN, TIME AND SETTING： Completely randomized, controlled experiment based on neurobiochemistry was performed at the Pharmacological Laboratory, Henan University of Traditional Chinese Medicine from September to December 2003. MATERIALS： Schisandra chinensis was purchased from Henan Provincial Medicinal Company. Schisandra chinensis polysaccharide was obtained by water extraction and alcohol precipitation. Kangnaoling pellets were provided by Liaoning Tianlong Pharmaceutical （batch No. 20030804; state drug permit No. H21023095）. A total of 50 six-week-old Kunming mice were randomly divided into five groups： blank control, model, Kangnaoling, high and low dosage Schisandra chinensis polysaccharide groups, with 10 mice per group. METHODS： Mice in the blank control group were subcutaneously injected with 0.5 mL/20 g normal saline into the nape of the neck each day, while the remaining mice were subcutaneously injected with 5% D-galactose saline solution （0.5 mL/20 g） in the nape for 40 days to induce a brain aging model. On day 11, mice in the high and low dosage Schisandra chinensis polysaccharide groups were intragastrically infused with 20 mg/mL and 10 mg/mL Schisandra chinensis polysaccharide solution （0.2 mL/10 g）, respectively. Mice from the Kangnaoling group were intragastrically infused with 35 mg/mL Kangnaoling suspension （0.2 mL/10 g）, and the mice in the model group were intragastrically infused with the same volume of normal saline （0.2 mL/10 g） once per day for 30 consecutive days. MAIN OUTCOME MEASURES： Two hours after the final administration, pathohistological changes in the cerebral cortex and hippocampus were observed using hematoxylin ＆ eosin staining. AChE activity was detected using chromatometry. Monoamine neurotransmitter content was measured using fluorimetry. Learning and memory was measured using the step down test and darkness avoidance test. RESULTS： Both Schisandra chinensis polysaccharide and Kangnaoling improved pathological injury to the cerebral cortex and hippocampus in a mouse model of brain aging. Compared with the blank control group, AChE activity and content of norepinephrine （NA）, dopamine （DA）, and 5-hydroxytryptamine （5-HT） were significantly decreased in the model group （P 〈 0.01 ）. In contrast, AChE activity and NA, DA, and 5-HT levels significantly increased in the Kangnaoling and high dosage Schisandra chinensis polysaccharide groups （P 〈 0.01）, while NA levels significantly increased in the low dosage Schisandra chinensis polysaccharide group （P 〈 0.01）. Drug treatment improved learning and memory abilities （P 〈 0.01 or P 〈 0.05）. CONCLUSION： Schisandra chinensis polysaccharide significantly increased levels of central neurotransmitters and improved learning and memory in a mouse model of brain aging. The effects of Schisandra chinensis polysaccharide were equal to that of Kangnaoling pellets.

Fingolimod(FTY720) improves postoperative cognitive dysfunction in mice subjected to D-galactose-induced aging

Neurocognitive dysfunction is a common postoperative complication,especially in older adult patients.Fingolimod(FTY720)is a sphingosine-1-phosphate receptor modulator that has been found to be neuroprotective in several animal models of central nervous system disease.However,few reports have examined whether FTY720 could mitigate postoperative cognitive dysfunction.In this study,we investigated whether FTY720 could prevent postoperative neurocognitive impairment in mice subjected to D-galactose-induced aging.We induced an accelerated model of aging by administering an intraperitoneal injection of D-galactose.Subsequently,we performed a partial hepatolobectomy under sevoflurane anesthesia.FTY720(1 mg/kg)was administered intraperitoneally 3 hours before and 24 hours after anesthesia and surgery.Our results indicated that anesthesia and surgery significantly impaired spatial memory in the Y-maze test 6 hours after surgery.We also found that problem solving ability and long-term memory in the puzzle box test on postoperative days 2–4 were significantly improved by FTY720 treatment.Immunohistochemical staining and western blot assay demonstrated that FTY720 significantly inhibited microglial activation in the hippocampal CA1 region of mice 6 hours and 3 days after anesthesia,and down-regulated the expression of synaptic-related proteins postsynaptic density protein 95 and GluR2 in the hippocampus.These results indicate that FTY720 improved postoperative neurocognitive dysfunction in mice subjected to D-galactose-induced aging.This study was approved by the Experimental Animal Ethics Committee of the Third Xiangya Hospital of Central South University of China(approval No.LLSC(LA)2016-025)on September 27,2016.

Moderate exercise prevents neurodegeneration in D-galactose-induced aging mice

D-galactose has been widely used in aging research because of its efficacy in inducing senescence and accelerating aging in animal models. The present study investigated the benefits of exercise for preventing neurodegeneration, such as synaptic plasticity, spatial learning and memory abilities, in mouse models of aging. D-galactose-induced aging mice were administered daily subcutaneous injections of D-galactose at the base of the neck for 10 consecutive weeks. Then, the mice were subjected to exercise training by running on a treadmill for 6 days a week. Shortened escape latency in a Morris water maze test indicated that exercise improved learning and memory in aging mice. The ameliorative changes were likely induced by an upregulation of Bcl-2 and brain-derived neurotrophic factor, the repression of apoptosis factors such as Fas and Bax, and an increase in the activity of glucose transporters-1 and 4. The data suggest moderate exercise may retard or inhibit neurodegeneration in D-galactose-induced aging mice.

NADPH Oxidase-dependent Oxidative Stress and Mitochondrial Damage in Hippocampus of D-galactose-induced Aging Rats

Mitochondrial DNA(mtDNA) common deletion(CD) plays a significant role in aging and age-related diseases.In this study,we used D-galactose(D-gal) to generate an animal model of aging and the involvement and causative mechanisms of mitochondrial damage in such a model were investigated.Twenty 5-week-old male Sprague-Dawley rats were randomly divided into two groups:D-gal group(n=10) and control group(n=10).The quantity of the mtDNA CD in the hippocampus was determined using a TaqMan real-time PCR assay.Transmission electron microscopy was used to observe the mitochondrial ultrastructure in the hippocampus.Western blot was used to detect the protein levels of NADPH oxidase(NOX) and uncoupling protein 2(UCP2).We found that the level of mtDNA CD was significantly higher in the hippocampus of D-gal-induced aging rats than in control rats.In comparison with the control group,the mitochondrial ultrastructure in the hippocampus of D-gal-treated rats was damaged,and the protein levels of NOX and UCP2 were significantly increased in the hippocampus of D-gal-induced aging rats.This study demonstrated that the levels of mtDNA CD and NOX protein expression were significantly increased in the hippocampus of D-gal-induced aging rats.These findings indicate that NOX-dependent reactive oxygen species generation may contribute to D-gal-induced mitochondrial damage.

The Antioxidant Effects of L-carnitine on D-galactose Induced Aging Mice

[Objective] To study the antioxidant effects of LC on D-galactose induced aging mice. [Method] 50 mice were randomly divided into blank control group, D-galactose model group, LC treatment groups at three levels of 0.25, 0.5 and 1.0 g/（kg d）, a total of 5 groups. Using the subacute D-galactose induced aging models, the mice were killed after 6 weeks of experiment and the activity of Superoxide dismutase （SOD）, Glutathione peroxidase （GSH-Px） and Malondialdehyde （MDA） content in plasma, brain and liver tissue were determined. [ Result.] The activity of SOD and GSH-Px in plasma, brain and liver tissue were significantly increased after treated with LC, while the content of MDA were decreased with a dose-dependent manner. [ Conclusion] LC had anti-aging effects in mice, and the mechanism may be correlated with the antioxidation.

Protective effects of (-)-epigallocatechin-3-gallate on D-galactose-induced neuronal apoptosis in mice

BACKGROUND： The neuroprotective effects of （-）-epigallocatechin-3-gallate （EGCG）, the main polyphenolic constituent of green tea, have been widely reported. However, the action mechanisms, in particular in D-galactose-induced aging mice, remain poorly understood. OBJECTIVE： The present study investigated the protective effects of EGCG on D-galactose-induced hippocampus neuronal apoptosis in aging mice, as well as the relationship with expression of p751CD, JNK2, and p53 proteins. DESIGN, TIME AND SETTING： A randomized, controlled, molecular biological, animal experiment was performed at the Laboratory of Pharmacology, Pharmaceutical College of China Medical University, China, from September 2006 to July 2008. MATERIALS： D-galactose and EGCG （Sigma, USA）, as well as terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling （TUNEL） In Situ Cell Apoptosis Detection Kit （Promega, USA）, were used in this study. METHODS： A total of 64 mice were equally and randomly divided into D-galactose model, low-dose EGCG, high-dose EGCG, and control groups. Mice in the D-galactose model, low-dose EGCG, and high-dose EGCG groups were subcutaneously injected with 3% D-galactose （150 mg/kg）, daily for 6 weeks, to establish a mouse model of aging. Mice in the control group were treated with saline （5 mL/kg）. At 3 weeks following injection, mice in the low-dose EGCG and high-dose EGCG groups were orally administered EGCG at a dose of 2 mg/kg and 6 mg/kg, respectively, once a day, for 4 consecutive days. Mice in the control and D-galactose model groups received distilled water （5 mL/kg）. MAIN OUTCOME MEASURES： Memory function was evaluated using a step-through passive avoidance test. Neuronal apoptosis in the mouse hippocampus was detected using TUNEL staining. Expression levels of the intracellular domain of the p75 neurotrophin receptor （p75NTR）-p751CD, JNK2, and p53 proteins in the hippocampus were determined using Western blot analysis. RESULTS： The aging mouse model was induced by subcutaneous injection of D-galactose, which resulted in obvious memory impairment, increased apoptotic index, and increased protein expression levels of p751CD, JNK2, and p53 in the hippocampus, compared with control mice （P 〈 0.01）. Oral EGCG administration （2 or 6 mg/kg） for 4 weeks significantly improved levels of memory deficit in the aging mice and reduced apoptotic indices and protein expression levels of p751CD, JNK2, and p53 in the mouse hippocampus （P 〈 0.01）. CONCLUSION： Results from this study demonstrated increased protein expression levels of p751CD, JNK2, and p53, as well as increased hippocampal neuronal apoptosis in a D-galactose-induced mouse model of aging. EGCG provided protective effects against D-galactose-induced neuronal apoptosis in the hippocampus by reducing protein expression levels of p751CD, JNK2, and p53 proteins in the hippocampus of aging mice.

Study on Learning and Memory Ability of Mice Induced by Different Doses of D-galactose

Aim:To explore the influence of different doses of D-galactose on learning memory capacity in mice.Methods:The 2-month-old KM mice were randomly divided into D-galactose-treated groups (75,100,150,300 mg·kg^-1) and normal control group,with 12 mice in each group.The corresponding dose of D-galactose was administered subcutaneously to the back of the neck,and normal control group was injected subcutaneously with saline for 8 weeks.Learning memory capacity of mice was detected through Morris water maze,step-down passive avoidance test and new object recognition test.Meanwhile,the enzymatic indicators in the brain were determined to detect the damage degree in mice with different doses of D-galactose.Results:Compared with the normal control group,the spatial and non-spatial cognitive functions and brain enzyme levels of D-galactose in each dose group was damaged to varying degrees,especially the dose of 100 mg·kg-1 group.In the water maze experiment,D-galactose groups significantly prolonged the time of crossing the platform for the first time and decreased the number of crossing platforms,especially at the dose of 100 mg·kg-1 (P < 0.05);in the new object recognition experiment,discrimination index was significantly decreased in each D-galactose group (P < 0.01),and the dose of 100 mg·kg-1 was most obvious;in addition,D-galactose could significantly increase the level of acetylcholinesterase (AChE)(P < 0.01),decrease the levels of superoxide dismutase (SOD),glutathione peroxidase (GSH-Px),and total antioxidant capacity (T-AOC)(P < 0.05 or P < 0.01) in the mice brain.Conclusion:Subcutaneous injection of low-medium-high dose of D-galactose for 8 weeks in the back of the neck can cause changes in brain parameters in mice,but the effects of different doses of D-galactose on some indicators are significantly different.D-galactose model is effective and stable at the dose of 100 mg·kg-1.

知母-黄柏对D-gal认知功能障碍模型小鼠海马神经元细胞异常自噬的影响

目的:通过观察海马内自噬相关蛋白的表达水平探讨知母-黄柏药对(AP)改善D-半乳糖(D-gal)模型小鼠认知功能障碍的作用机制。方法:75只小鼠随机分为空白组、模型组、吡拉西坦组、AP组,自噬诱导剂依维莫司(RAD001)组,除空白组腹腔注射生理盐水外,其余各组均注射0.125 g·kg^(-1)·d^(-1)的D-gal以复制认知功能障碍模型。通过水迷宫实验测试小鼠认知功能障碍情况,HE染色及尼氏染色法观察各组小鼠海马组织神经元状态以及尼氏小体数量,免疫组化法检测海马中LC3及P62阳性细胞数量的表达,Western Blot实验检测海马中与自噬相关蛋白ULK1、LC3、Beclin-1、P62等蛋白相对表达水平,实时荧光定量PCR法检测海马中ULK1、Beclin-1、P62等基因表达。结果:与空白组相比,模型组小鼠的学习记忆能力显著降低,海马CA1区神经元和尼氏体出现严重丢失,且排列紊乱;海马内ULK1、LC3、Beclin-1蛋白及基因表达升高(P<0.01,P<0.05),P62蛋白及基因表达下降(P<0.01)。与模型组相比,吡拉西坦组、AP组小鼠学习记忆能力显著提高,神经元、尼氏体丢失现象减少;海马内ULK1、LC3、Beclin-1蛋白及基因表达下降(P<0.01),P62蛋白及基因表达升高(P<0.01)。RAD001组显示AP给药后可部分逆转细胞过度自噬现象。结论:AP可以改善D-gal模型小鼠的认知功能障碍,其机制可能是通过抑制海马区细胞过度自噬来实现的。

Con A、α-Galcer与LPS/D-Gal N诱导免疫性肝损伤小鼠NKT细胞功能改变的比较研究

目的:通过比较三种免疫性肝损伤模型小鼠NKT细胞功能改变情况,寻找一种在病理生理机制上更接近临床特点的免疫性肝损伤动物模型。方法:40只小鼠随机分为空白对照组、Con A模型组、α-Galcer模型组、LPS/D-Gal N模型组,每组10只。Con A模型组尾静脉注射ConA溶液(18 mg/kg),α-Galcer模型组腹腔注射α-Galcer溶液(40μg/kg),LPS/D-Gal N模型组腹腔注射LPS溶液(10μg/kg)和D-Gal N溶液(700 mg/kg)。造模完成后8 h,检测小鼠血清转氨酶ALT、AST水平,计算肝指数,采用HE染色法观察肝组织病理改变情况,流式细胞仪分析肝组织NKT细胞含量,Western blot法检测肝组织中TNF-α、IFN-γ、IL-6蛋白表达情况。结果:与空白对照组比较,各模型组小鼠血清ALT、AST水平均显著升高(P<0.01),肝指数增加(P<0.01或P<0.05),肝组织病理损伤明显,NKT细胞含量显著增加(P<0.01或P<0.05),TNF-α、IFN-γ、IL-6表达均明显上调(P<0.01);各模型组之间比较,α-Galcer模型组血清ALT、AST含量显著低于Con A组(P<0.05),病理损伤也相对较轻,LPS/D-Gal N模型组NKT细胞含量明显低于其余两组(P<0.05)。结论:Con A、α-Galcer和LPS/D-Gal N诱导的免疫性肝损伤模型小鼠NKT细胞明显激活,介导炎症紊乱;其中,以Con A诱导的动物模型肝脏病理损伤及免疫紊乱最为明显,更符合疾病临床特点,可作为免疫性肝损伤的首选模型。

降心丹对D-gal模型小鼠免疫功能的影响

目的——探讨中药降心丹对D-gal所致衰老模型鼠免疫功能的影响。方法——KM小鼠随机分为6组:正常对照组、衰老模型组、脑复康西药对照组、降心丹低剂量组、降心丹中剂量组、降心丹高剂量组;应用MTT法测定小鼠T淋巴细胞的增殖能力;ELISA检测法测定IL-2水平的变化。结果——降心丹能明显提高衰老小鼠T淋巴细胞增殖能力和IL-2水平。结论——中药降心丹能改善衰老模型鼠免疫功能。

D-半乳糖(D-gal)通过激活p38MAPK通路引起小鼠睾丸TM4支持细胞屏障功能损伤

目的研究D-半乳糖(D-gal)对小鼠TM4睾丸支持细胞屏障功能的损伤作用及机制。方法TM4细胞分为正常对照组和(25、50、100、150、200、250)mmol/L D-gal刺激组,噻唑蓝(MTT)法检测TM4细胞增殖活性,Western blot法检测TM4细胞紧密连接相关蛋白闭锁小带蛋白1(ZO-1)和闭合蛋白(occludin),黏附连接相关蛋白神经钙黏蛋白(N-cadherin)、上皮钙黏蛋白(E-cadherin)和β联蛋白(β-catenin),缝隙连接相关蛋白连接子蛋白43(CX43),骨架蛋白波形蛋白(vimentin)和丝裂原激活蛋白激酶(MAPK)信号通路相关蛋白胞外信号调节激酶1/2(ERK1/2)、Janus激酶(JNK)和p38MAPK的蛋白表达及磷酸化水平。结果与正常对照组比较,D-gal浓度大于50 mmol/L时,细胞活力显著下降;ZO-1、occludin、N-cadherin、E-cadherin和β-catenin的蛋白表达水平均显著降低,p38MAPK蛋白磷酸化水平显著增加,而CX43、vimentin及ERK1/2、JNK蛋白及磷酸化水平无明显变化。结论D-gal可引起TM4睾丸支持细胞紧密连接损伤和黏附连接损伤,可能与激活p38MAPK通路有关。

岩藻黄素抗D-gal诱导SH-SY5Y细胞衰老作用及机制研究

衰老相关的神经退行性疾病发病率不断增高,严重影响老年人生活质量,为探讨岩藻黄素(Fucoxanthin,FUCO)对神经细胞的抗衰老作用及其机制,采用D-gal诱导人神经母细胞瘤细胞(SH-SY5Y细胞)衰老,然后在细胞培养基中添加FUCO对细胞进行干预,检测其细胞活力、SA-β-半乳糖苷酶活性及细胞内丙二醛(MDA)含量,细胞内自噬体形成及自噬(Autophagy)相关蛋白的表达。研究结果显示,5,10μmol/L FUCO可明显抑制D-gal诱导的细胞衰老,显著提高SH-SY5Y细胞活力(P<0.05),降低SH-SY5Y细胞内SA-β-半乳糖苷酶的活性(P<0.05)和MDA含量(P<0.05),但20μmol/L FUCO的抑制作用不明显(P>0.05)。光学显微镜观察结果显示,5,10,20μmol/L FUCO组细胞内自噬体数量明显比模型组增多;Western blot检测结果显示,与模型组比较,10,20μmol/L FUCO组自噬相关蛋白ATG5表达增多、LC3Ⅱ/LC3Ⅰ增大、p-mTOR/mTOR减小(P<0.05)。表明FUCO具有抗D-gal诱导的SH-SY5Y细胞衰老的作用,其作用机制可能与适度调节自噬途径有关。

LPS/D-gal诱导小鼠急性肝炎模型及mTOR信号的变化

目的探索LPS/D-gal诱导的急性肝炎中mTOR信号的变化。方法LPS/D-gal通过腹腔注射ICR雌性小鼠诱导急性肝炎模型。观察记录24h内的存活率或在注射后6h收集血清和肝脏组织样本,进行相关的分析。结果LPS/D-gal注射24h内引起小鼠急性死亡。注射后6h,引起血清中转氨酶水平明显升高。肝脏组织炎性因子Tnfa和Il6表达水平上调。HE染色显示明显的炎症细胞浸润,研究结果表明LPS/D-gal可诱导ICR小鼠成为急性肝炎动物模型。此外,肝脏组织免疫印迹分析发现,mTOR和NF-κB信号通路被激活,凋亡相关蛋白Caspase-3的活性增加,凋亡特征性的DNA片段化也显著增强。然而mTOR信号的抑制剂雷帕霉素并不能控制LPS/D-gal引起的肝脏凋亡和提高存活率。结论mTOR信号在LPS/D-gal诱导的急性肝炎的致病机制中可能发挥多重作用。