Effects of distinct n-6 to n-3 polyunsaturated fatty acid ratios on insulin resistant and AD-like phenotypes in high-fat diets-fed APP/PS1 mice.

Type 2 diabetes mellitus (T2DM) and Alzheimer's disease (AD) are prevalent diseases with similar pathophysiological characteristics and genetic predispositions. Polyunsaturated fatty acids (PUFAs) are essential in maintaining normal brain function. However, little is known about the effect of dietary n-6/n-3 PUFA ratio on AD-like pathology, particularly in high-fat diet (HFD)-fed AD model mice. In the present study, the APP/PS1 mice were fed with 60 % HFD for 3.5 months to induce insulin resistance. After that, 45 % HFD with various n-6/n-3 PUFA ratios (n-6/n-3 = 1:1, 5:1 or 16:1) was applied for an additional 3.5 months of treatment. The behavior of mice was observed using the water maze after dietary intervention. The animals were euthanized after behavioral testing, and serum and tissue samples were collected for biochemical, histological, and pathological tests and evaluation. HFD caused insulin resistance, increased serum IL-6 and TNF-α levels, cortical soluble Aß1-40, Aß1-42 content, and cortical n-6/n-3 PUFA ratio in APP/PS1 mice. Increased APP and BACE1 protein expression and p-IR/IR ratio but decreased pro-inflammatory cytokines mRNA expression was detected in the cortex of 60 % HFD-fed APP/PS1 mice. N-3 PUFAs-rich diet (n-6/n-3 = 1:1) alleviated insulin resistance and hyperlipidemia caused by 60 % HFD. Cortical soluble Aß1-40 and Aß1-42 contents, as well as the expression of cortical APP, GLUT1, GLUT3, insulin metabolism-related molecules, and NF-κB pathway downstream pro-inflammatory cytokines, were found to be n-6/n-3 PUFAs ratio-dependent, indicating that dietary n-6/n-3 PUFA ratio plays a critical role in modifying the responses of serum inflammatory cytokines, AD pathology, cortical n-6/n-3 PUFAs ratio, insulin signaling, and neuroinflammation to HFD treatment.

Comprehensive utilization of palm kernel cake for producing mannose and manno-oligosaccharide mixture and yeast culture.

Palm kernel cake (PKC) is an agricultural waste derived from palm kernel oil manufacturing, and its production is increasing year by year. It is very urgent to process this agricultural waste in an environmentally friendly way. Here, PKC was used to produce mannose and manno-oligosaccharides mixture (MMOM) and yeast culture (YC) through enzymolysis and solid-state fermentation (SSF). In enzymolysis, five factors were optimized separately and a response surface methodology analysis was performed. Then, enzymolysis of PKC was carried out at the optimal condition, and the extraction efficiency of mannose and manno-oligosaccharides reached 68.90% with mannose concentration achieving 60.27 g/L. After enzymolysis, the enzymatic hydrolysate was dried by spray drying, and the contents of MMOM reached 42.9%. In SSF, the enzymolysis residues were utilized with inoculating Saccharomyces cerevisiae for yielding YC. After optimization, the cells number of S. cerevisiae reached 2.08 × 109 cells/g and the crude protein content was increased to 27.31%. Therefore, a novel approach to produce feed additives, including MMOM and YC, with high value by comprehensive utilization of PKC was proposed, which has good application prospects in the breeding industry. KEY POINTS: • New idea for the comprehensive utilization of PKC is proposed. • PKC was used to produce mannose and mannan-oligosaccharides mixture (MMOM) by enzymolysis and spray drying. • The enzymolysis residues were reused via SSF for producing yeast culture (YC).

High-fat diet induced discrepant peripheral and central nervous systems insulin resistance in APPswe/PS1dE9 and wild-type C57BL/6J mice.

This study was designed to examine whether AD pathological phenotype in APPswe/PS1dE9 (APP/PS1) mice exposed to continuous high-fat diet predispose these murine models to metabolic dysfunction and neuropathological impairments. One-month old male APP/PS1 and C57BL/6J mice were provided with 60% high-fat diet for 6.5 months. After dietary intervention, metabolic phenotyping, cognitive behaviors, AD-related brain pathological changes and insulin signaling were compared. high fat diet induced hyperglycemia, hypercholesterolemia, and aggravated inflammatory stress in both APP/PS1 and C57BL/6J mice. Compared with C57BL/6J control mice, APP/PS1 mice showed lower glucose transporter protein expression in liver, muscle, and brain. High-fat diet caused a decrease of glucose transporter protein expression in muscle and liver but increased cortical glucose transporter protein expression in APP/PS1 mice. High-fat diet-fed APP/PS1 mice demonstrated decreased cognitive function, as well as elevated cortical soluble amyloid-ß levels and APP protein expression. Decrease in cortical IR, p-IR protein expression and p-GSK3ß/GSK3ß ratio were observed in high-fat diet-fed APP/PS1 mice. High-fat diet caused discrepant peripheral and central nervous system metabolic phenotype in APP/PS1 and C57BL/6J mice. AD pathological phenotype might accelerate metabolic changes and cognitive impairment in APP/PS1 mice treated with HFD.

DHA and vitamin E antagonized the Aß25-35-mediated neuron oxidative damage through activation of Nrf2 signaling pathways and regulation of CD36, SRB1 and FABP5 expression in PC12 cells.

The present study was designed to explore the neuroprotective effects of docosahexaenoic acid (DHA) and/or vitamin E (VE) in vitro. The PC12 cells were pretreated with DHA and/or VE for 4 h, followed by 50 µmol L-1 Aß25-35 treatments for another 48 h. The cells were then collected and used for the measurements of oxidative stress parameters. Real time-PCR and western blot were applied to measure fatty acid transporters, Nrf2 and its downstream antioxidant targets' gene and protein expression. Our results indicated that the Aß25-35 treatment inhibited cellular growth, increased intracellular ROS generation and decreased the mitochondrial membrane potential. The Aß25-35 treatment decreased the total antioxidant capacity (T-AOC), whereas it increased the MDA levels in neuron cells. Pretreatment of cells with VE or DHA could antagonize the Aß25-35-mediated cell growth inhibition and mitochondrial membrane potential decline. Activation of the Nrf2 signaling pathway and regulation of CD36, SRB1 and FABP5 expression were observed in DHA- and DHA + VE-pretreated cells. Our results indicated a synergistic effect of DHA and VE in antagonizing the oxidative damage caused by Aß25-35 in the PC12 cells. The results of the present study will shed light on the application of nutritional intervention for DHA and VE in preventing neuronal damage-related diseases.

Diminished circulating retinol and elevated α-TOH/retinol ratio predict an increased risk of cognitive decline in aging Chinese adults, especially in subjects with ApoE2 or ApoE4 genotype.

OBJECTIVE: The current study evaluated the relationship between circulating fat soluble vitamin status and cognition in aging Chinese population. METHODS: A cross-sectional study was carried out in 1754 community residents aged 55-80 years aiming to evaluate the relationship between circulating α-tocopherol and retinol status and cognition. The effect of ApoE genetic polymorphism on the relationship between vitamins and cognition was also explored. RESULTS: Our results indicated that serum retinol status positively correlated with cognitive performance; while, serum α-tocopherol (α-TOH)/retinol ratio negatively correlated with cognitive performance. Mild cognitive impairment (MCI) subject demonstrated higher serum α-TOH status (P < 0.05), α-TOH/retinol ratio (P < 0.01) and lower retinol status (P < 0.01) than normal subjects. Subjects with ApoE4 genotype have lower serum retinol level (P < 0.05) and higher α-TOH/retinol ratio (P < 0.01) than subjects with ApoE3 genotype. MCI-ApoE4 carriers demonstrated the worst cognitive performance (P < 0.05) and exhibited higher serum TC, α-TOH and α-TOH/retinol ratio levels (P < 0.05), and lower LDL-C, retinol and lipid-adjusted retinol status (P < 0.05). MCI-ApoE2 subjects showed higher serum TC, HDL-C content and α-TOH/retinol ratio (P < 0.05); and lower serum retinol and lipid-adjusted retinol status (P < 0.05). CONCLUSION: Lower circulating retinol and higher α-TOH/retinol ratio potentially predicts an increased risk for the development of cognitive decline in aging Chinese adults. ApoE2 or E4 carriers with higher circulating α-TOH/retinol ratio infer poor cognitive performance and an increased risk of developing MCI.

[Correlation of dietary quality and blood glucose and lipid of the elderly in the community in Beijing from 2013 to 2015].

OBJECTIVE: To evaluate the diet quality of the Chinese elderly using adjusted Chinese Diet Balance Index( DBI-07) and to explore the association between dietary patterns and blood glucose and lipid with the aiming to provide scientific basis and theoretical support for nutrition education intervention. METHODS: A total of 1158 participants aged 50-90 involved in this cross-sectional study. The subjects were randomly recruited from Nanyuan Community and Wulituo Community by posting small advertisements in 2013-2015. Questionnaires were used to collect the information of demographic characters. Food intake information was collected by food frequency questionnaire( FFQ) method, and the dietary quality was evaluated by DBI-07 scoring and evaluating system. Peripheral vein blood samples were collected for the measurement of general biochemical parameters. RESULTS: The overall dietary pattern of the aging adults was imbalance. The major problem of the elderly was insufficient intakes in vegetables, fruits, milk, soybean and animal derived food. There was significant difference in blood glucose and high density lipoprotein-cholesterol levels between the subjects with different dietary patterns( P < 0. 05). CONCLUSION: Imbalanced dietary pattern was detected of the elderly in Beijing. Balanced dietary pattern which is rich in vegetables & fruits, milk, soybean and moderate animal derived foods should be recommended to the elderly.

Association of ApoE Genetic Polymorphism and Type 2 Diabetes with Cognition in Non-Demented Aging Chinese Adults: A Community Based Cross-Sectional Study.

Apolipoprotein E (ApoE) gene polymorphism has been implicated in predisposition to diabetes and dementia in old population, but the results from the different studies were inconclusive. A cross-sectional study was carried out to explore the relationship among ApoE gene polymorphism, diabetes and cognition in non-demented aging Chinese adults. A total number of 1000 community dwellers aged 55 years and above were randomly recruited. Demographic information of the participants was collected using well designed self-administered questionnaires. The Montreal Cognitive Assessment (MoCA) test was employed to evaluate the cognitive status of the participants. Semi-quantitative food frequency questionnaire was used to obtain the dietary intake information. Fasting venous blood samples were taken for ApoE genotyping and serum lipid measurements. 238 participants were type 2 diabetes mellitus (T2DM) patients and 145 participants were ApoE4 carriers. ApoE 4-T2DM subjects had higher serum triglyceride (TG) concentration than E2 and E3 carriers (P < 0.05). T2DM subjects carrying ApoE4 had lower cognition than subjects with E2 or E3 carriers (P < 0.05). Comparing to non-type 2 diabetic mild cognitive impaired (nT2DM-MCI) subjects, the type 2 diabetic mild cognitive impaired (T2DM-MCI) subjects have higher serum glucose (Glu) level and lower high-density lipoprotein (HDL-C) level (P < 0.05). The T2DM-MCI subjects carrying ApoE4 have lower cognition than E2 and E3 carriers (P <0.05); and the interaction of ApoE genotype with T2DM was detected (P < 0.05). Our results indicated the association among ApoE gene polymorphism, T2DM and cognitive performance in non-demented aging population. The carrying of ApoE4 predisposed the T2DM subjects and the T2DM-MCI subjects to have poor cognitive performance. Additional experimental studies are required to explore the mechanism that ApoE genotype modifies the risk for cognitive impairment in aging subjects with T2DM.

Dietary Vitamin E Status Dictates Oxidative Stress Outcomes by Modulating Effects of Fish Oil Supplementation in Alzheimer Disease Model APPswe/PS1dE9 Mice.

Quite a number of studies have examined the effects of fish oil supplementation on cognitive performance in different transgenic animal models of Alzheimer's disease (AD). However, inconsistent and controversial outcomes have been derived from these experiments. In order to investigate whether the beneficial effect of fish oil supplementation on cognition was dietary VE status associated, fish oil dietary intervention was carried out in transgenic APPswe/PS1dE9 (APP/PS1) mice. Control mice (C57BL/6J mice) were fed a normal control diet. APP/PS1 mice were assigned to a normal control diet group and low VE diet + fish oil supplement, normal VE diet + fish oil supplement, and high VE diet + fish oil supplement groups, respectively. After 7 months of dietary intervention, we found that fish oil supplementation improved behavioral performance, alleviated brain beta-amyloid (Aß) plaque burden, and attenuated the oxidative stress in APP/PS1 mice by increasing cortical GSH content and total antioxidant capacity, as well as by decreasing MDA level. Fish oil treatment increased cortical n-3 PUFA concentration and decreased n-6/n-3 PUFA ratio in APP/PS1 mice. Fatty acid transporters, Nrf2 and downstream targets involved in cortical and hippocampal antioxidant system were also modulated by fish oil-supplemented diet. Our data demonstrate that fish oil supplementation exerts an enhanced modulatory effect on the antioxidant system and fatty acid concentrations in APP/PS1 mice fed on lowly or averagely concentrated level of VE-containing diet than in mice fed with VE-rich diet. The current data do support previous findings that already dictate the beneficial effect of n-3 PUFAs on cognitive function. Moreover, the cognition promoting effects of n-3 PUFAs may be dietary VE status related.

The Role of ApoE Polymorphism in the Relationship between Serum Steroid Hormone Levels and Cognition in Older Chinese Adults: A Cross-Sectional Study.

BACKGROUND: Epidemiology studies have indicated an association of apolipoprotein E (ApoE) genetic polymorphism and circulating steroid hormone levels with the risk of Alzheimer's disease. The established physiologic relationship between apolipoproteins and steroid hormone indicate an important role of ApoE polymorphism in impacting the relationship between serum steroid hormones and cognition in the elderly. STUDY DESIGN: A total of 500 Chinese adults aged between 50 and 75 participated in this community-based cross-sectional study. Blood samples were collected in the morning for ApoE genotyping and serum parameter assessment. Cognitive performance of participants was evaluated by Montreal Cognitive Assessment test. RESULTS: Age, gender, educational level, smoking, and physical activity levels are factors associated with cognitive performance in this older Chinese adults. Compared to the control subjects, MCI subjects demonstrated higher serum total cholesterol, HDL-C, and estradiol status (P < 0.05). ApoE genotype difference of serum lipid profile was observed with a relatively higher mean serum triglyceride levels in ApoE2 and ApoE4 carriers (P < 0.05), and lower mean serum HDL-C level in ApoE4 carriers (P < 0.05). Memory and delayed recall ability was serum estradiol level related; and subjects with higher circulating estradiol concentration exhibited lower memory and delayed recall ability (P < 0.05). The association of serum estradiol and cortisol concentration with cognitive performance was ApoE genotypes dependent. Poor cognitive performance was observed in ApoE2 and ApoE4 carriers with higher serum estradiol level (P < 0.05). Moreover, ApoE2 and ApoE4 carriers with higher serum cortisol status demonstrated decreased language ability (P < 0.05). Multiple logistic regression analysis indicates that subjects with higher serum estradiol status may have an increased risk for MCI [OR = 2.004, 95% confidence interval (CI): 1.135, 3.540; P = 0.017]. ApoE2 carriers with higher serum steroid levels may be potentially predisposed to an increased risk of MCI (OR = 3.353; 95% CI: 1.135, 9.907; P = 0.029). CONCLUSION: Cognitive outcomes in older Chinese adults are associated with serum steroid hormone status. Higher serum steroid levels in ApoE2 carriers might pose an increased risk of MCI in the elderly.

ApoE rs429358 and rs7412 Polymorphism and Gender Differences of Serum Lipid Profile and Cognition in Aging Chinese Population.

ApoE gene polymorphism has been reportedly associated with serum lipids and cognition. However, very few studies have explored the combined effects of ApoE gene polymorphism and gender on serum lipid profile with subsequent impacts on cognition in Chinese population. A total of 1,000 Chinese community dwellers aged 55 years and above were recruited in this cross-sectional study. Demographic information of the participants was collected using well designed self-administered questionnaires. The Montreal Cognitive Assessment (MoCA) test was employed to evaluate the cognitive status of the participants. Semi-quantitative food frequency questionnaire (FFQ) was used to obtain the dietary intake information. Fasting venous blood samples were taken for ApoE genotyping and serum lipid measurements. Significant gender differences in cognition, serum lipid profile and dietary fat-rich foods consumption were observed (p < 0.05). Cognition of the subjects was found to be associated with ApoE genotypes (p < 0.05). ApoE rs429358 and rs7412 variants demonstrated a significant effect on cognitive performance in the male subjects; especially within the attention and language cognitive domains as well as the total MoCA score (p < 0.05), respectively. Serum lipid profile and cognition of Chinese adults are significantly linked with gender and ApoE genetic polymorphism. The ApoE variant rs429358 is found to be notably associated with cognition in aging male Chinese population.