Inhibition of colorectal cancer in Alzheimer's disease is mediated by gut microbiota via induction of inflammatory tolerance.

Epidemiological studies have revealed an inverse relationship between the incidence of Alzheimer's disease (AD) and various cancers, including colorectal cancer (CRC). We aimed to determine whether the incidence of CRC is reduced in AD-like mice and whether gut microbiota confers resistance to tumorigenesis through inducing inflammatory tolerance using 16S ribosomal RNA gene sequencing and fecal microbiota transplantation (FMT). AD-like mice experienced a significantly decreased incidence of CRC tumorigenesis induced by azoxymethane-dextran sodium sulfate as evidenced by suppressed intestinal inflammation compared with control mice. However, FMT from age-matched control mice reversed the inhibitory effects on the tumorigenesis of CRC and inflammatory response in AD-like mice. The key bacterial genera in gut microbiota, including Prevotella, were increased in both the AD-like mice and in patients with amnestic mild cognitive impairment (aMCI) but were decreased in patients with CRC. Pretreatment with low-dose Prevotella-derived lipopolysaccharides (LPS) induced inflammatory tolerance both in vivo and in vitro and inhibited CRC tumorigenesis in mice. Imbalanced gut microbiota increased intestinal barrier permeability, which facilitated LPS absorption from the gut into the blood, causing cognitive decline in AD-like mice and patients with aMCI. These data reveal that intestinal Prevotella-derived LPS exerts a resistant effect to CRC tumorigenesis via inducing inflammatory tolerance in the presence of AD. These findings provide biological evidence demonstrating the inverse relationship between the incidence of AD and CRC.

The Therapeutic Effect of Buyang Huanwu Decoction on Mild Cognitive Impairment (MCI) in Patients with Diabetes.

OBJECTIVE: This study aims to comprehensively verify the efficacy of Buyang Huanwu Decoction in improving cognitive function in patients with diabetes. METHODS: Patients clinically diagnosed with mild cognitive impairment (MCI) assigned to either the placebo group or the Buyang Huanwu Decoction group. After strict screening and exclusions, a total of 156 participants completed the clinical trial, with 76 in the placebo group and 80 in the Buyang Huanwu Decoction group. RESULTS: After treatment, Buyang Huanwu Decoction group showed higher Mini-Mental State Examination and Montreal Cognitive Assessment scores compared to placebo (p < 0.05). Memory and Executive Screening, Boston Naming Test, and Animal Fluency Test scores were also higher in the treatment group (p < 0.05). No significant differences were found in DST and CDT scores (p > 0.05). Trail Making Test scores were lower in the treatment group (p < 0.05). No significant difference was observed between the two groups in terms of complications (p > 0.05). CONCLUSION: Patients receiving Buyang Huanwu Decoction treatment demonstrated improvement in cognitive function, showing positive effects and providing preliminary evidence for the role of Buyang Huanwu Decoction in improving cognitive function in patients with diabetes. This suggests its potential for clinical application and further promotion.

Oxidative stress suppresses PHB2-mediated mitophagy in ß-cells via the Nrf2/PHB2 pathway.

AIMS/INTRODUCTION: Mitochondrial damage caused by oxidative stress is a main driver of pancreatic ß-cell dysfunction in the pathogenesis of type 2 diabetes mellitus. Prohibitin2 (PHB2) is a vital inner mitochondrial membrane protein that participates in mitophagy to remove the damaged mitochondria. This study aimed to investigate the role and mechanisms of PHB2-mediated mitophagy in oxidative stress-induced pancreatic ß-cell dysfunction. MATERIALS AND METHODS: PHB2 and mitophagy-related protein expression were analyzed by real-time polymerase chain reaction and western blotting in RINm5F cells treated with H2O2 and islets of diabetic rats. Mitophagy was observed by mitochondrial and lysosome colocalization. RINm5F cells were transfected by phb2 siRNA or overexpression plasmid to explore the role of PHB2 in mitophagy of RINm5F cells. The mechanism of Nrf2 regulating PHB2 was explored by Nrf2 inhibitor and agonist. RESULTS: The expression of PHB2, mitophagy related protein PINK1, and Parkin were decreased in RINm5F cells incubated with H2O2 and in islets of diabetic rats. Overexpression of PHB2 protected ß-cells from oxidative stress by promoting mitophagy and inhibiting cell apoptosis, whereas transfection with PHB2 siRNA suppressed mitophagy. Furthermore, PHB2-mediated mitophagy induced by oxidative stress was through the Nrf2/PHB2 pathway in ß-cells. Antioxidant NAC alleviated oxidative stress injury by promoting PHB2-mediated mitophagy. CONCLUSION: Our study suggested that PHB2-mediated mitophagy can protect ß-cells from apoptosis via the Nrf2/PHB2 pathway under oxidative stress. Antioxidants may protect ß-cell from oxidative stress by prompting PHB2-mediated mitophagy. PHB2-mediated mitophagy as a potential mechanism takes part in the oxidative stress induced ß-cell injury.

Oxidative stress mediates hippocampal neuronal apoptosis through ROS/JNK/P53 pathway in rats with PTSD triggered by high-voltage electrical burn.

BACKGROUND: The pathogenesis of post-traumatic stress disorder (PTSD) triggered by high-voltage electrical burn (HVEB) remains unclear and the oxidative stress plays a role in this process. The purpose of this study is to investigate the underlying mechanism of oxidative stress mediates hippocampal neuronal apoptosis in rats with PTSD triggered by HVEB. MATERIALS AND METHODS: The PTSD rat model was developed by stimulating with high voltage electricity and screened using behavioral performance including Morris water maze (MWM), elevated plus-maze (EPM) and open-field test (OFT). The reactive oxygen species (ROS) generation was measured by DHE fluorescence staining or flow cytometry. Western blotting assay was used to detect the proteins of p-JNK, JNK, P53, PUMA, Bcl-2 and Bax in hippocampal tissue or HT22 cells treated with electrical stimulation. RESULTS: The serum MDA and 8-OHdG levels were increased (P < 0.001), while the activities of SOD and CAT were decreased (P < 0.001) significantly in patients with HVEB. Behavioral test results showed that high-voltage electric stimulation induced the PTSD-like symptoms and the ROS-JNK-P53 pathway was involved in the neuronal apoptosis in rats with PTSD induced by HVEB. In vitro experiments further confirmed the electrical stimulation induced neuronal apoptosis through ROS/JNK/P53 signaling pathway and the antioxidant NAC could rescued the ROS generation, activation of JNK/P53 proteins and improved the cell apoptosis rate in HT22 cells. Finally, the JNK inhibitor SP600125 could significantly inhibited the percentage of HT22 cell apoptosis induced by electrical stimulation (P < 0.001). CONCLUSIONS: These results indicated that oxidative stress mediates hippocampal neuronal apoptosis through ROS/JNK/P53 pathway in rats with PTSD triggered by HVEB.

Relationship between key continuous glucose monitoring-derived metrics and specific cognitive domains in patients with type 2 diabetes mellitus.

BACKGROUND: Continuous glucose monitoring (CGM)-derived time in range (TIR) is closely associated with micro- and macrovascular complications in type 2 diabetes mellitus (T2DM). This study was performed to investigate the relationship between key CGM-derived metrics and specific cognitive domains in patients with T2DM. METHODS: Outpatients with T2DM who were otherwise healthy were recruited for this study. A battery of neuropsychological tests was performed to evaluate cognitive function, including memory, executive functioning, visuospatial ability, attention, and language. Participants wore a blinded flash continuous glucose monitoring (FGM) system for 72 h. The key FGM-derived metrics were calculated, including TIR, time below range (TBR), time above range (TAR), glucose coefficient of variation (CV), and mean amplitude of glycemic excursions (MAGE). Furthermore, the glycemia risk index (GRI) was also calculated by the GRI formula. Binary logistic regression was used to assess risk factors for TBR, and we further analysed the associations between neuropsychological test results and key FGM-derived metrics with multiple linear regressions. RESULTS: A total of 96 outpatients with T2DM were recruited for this study, with 45.8% experiencing hypoglycemia (TBR< 3.9 mmol/L). Spearman analysis results revealed that a higher TBR< 3.9 mmol/L was correlated with worse performance on the Trail Making Test A (TMTA), Clock Drawing Test (CDT), and cued recall scores (P < 0.05). Logistic regression analysis results indicated that the TMTA (OR = 1.010, P = 0.036) and CDT (OR = 0.429, P = 0.016) scores were significant factors influencing the occurrence of TBR< 3.9 mmol/L. Multiple linear regressions further demonstrated that TBR< 3.9 mmol/L (ß = -0.214, P = 0.033), TAR> 13.9 mmol/L (ß = -0.216, P = 0.030) and TAR10.1-13.9 mmol/L (ß = 0.206, P = 0.042) were significantly correlated with cued recall scores after adjusting for confounding factors. However, TIR, GRI, CV and MAGE showed no significant correlation with the results of neuropsychological tests (P > 0.05). CONCLUSIONS: A higher TBR< 3.9 mmol/L and TAR> 13.9 mmol/L were associated with worse cognitive functions (memory, visuospatial ability, and executive functioning). Conversely, a higher TAR of 10.1-13.9 mmol/L was associated with better memory performance in memory tasks.

Association of stressful life events with cognitive impairment in patients with type 2 diabetes mellitus.

AIMS/INTRODUCTION: This study was carried out to investigate the relationship of stressful life events (SLEs) with the risk of cognitive impairment in patients with type 2 diabetes mellitus. MATERIALS AND METHODS: A total of 316 patients with type 2 diabetes mellitus aged >45 years were recruited in this study, and data on demographics, medical history, lifestyle characteristics and SLEs were collected. The cognitive status of patients was evaluated with a battery of cognitive function scales. Logistic regression analyses were carried out to evaluate the risk and protective factors for mild cognitive impairment (MCI). RESULTS: Participants, including 217 type 2 diabetes mellitus patients with MCI and 99 patients without MCI, were enrolled in the current study. Among the SLEs, the death of an offspring or parent (odds ratio [OR] 1.994, 95% confidence interval [CI] 1.017-3.908) was a risk factor for MCI after adjustment for age and education level. In the subgroup of participants aged <60 years, the death of an offspring or parent (OR 2.731, 95% CI 1.119-6.665) and financial difficulty (OR 22.205, 95% CI 4.365-112.966) were risk factors for the development of MCI, whereas high working pressure (OR 0.154, 95% CI 0.048-0.495) and career changes (OR 0.324, 95% CI 0.124-0.847) were protective factors for MCI. CONCLUSIONS: These data suggested that SLEs were associated with cognitive function in patients with type 2 diabetes mellitus. Adverse life events, such as the death of an offspring or parent, were risk factors for cognitive impairment, whereas high work pressure in middle-aged people was a protective factor against cognitive impairment.

Alzheimer's risk factor FERMT2 promotes the progression of colorectal carcinoma via Wnt/ß-catenin signaling pathway and contributes to the negative correlation between Alzheimer and cancer.

Increasing evidence from epidemiological studies indicate that Alzheimer's disease (AD) has a negative relationship with the incidence of cancers. Whether the Alzheimer's genetic risk factor, named as fermitin family homolog-2 (FERMT2), plays a pivotal part in the progressive process of colorectal carcinoma (CRC) yet remains unclear. This study revealed that FERMT2 was upregulated in CRC tissues which predicted an unfavorable outcome of CRC using the PrognoScan web tool. FERMT2 was co-expressed with a variety of genes have been linked with CRC occurrence and implicated in the infiltration of immune cell in CRC tissues. Overexpressing FERMT2 promoted CRC progression with upregulation of Wnt/ß-catenin signaling. Knockdown of FERMT2 suppressed the cell multiplication, colony formation rate, migration and invasion, along with the epithelial to mesenchymal transition (EMT) with downregulation Wnt/ß-catenin proteins in cells of CRC, while overexpressing ß-catenin reversed the inhibitory effects of silencing FERMT2 on the migration or invasion of CRC cells. Furthermore, Aß1-42 treated HT22 cells induced downregulation of FERMT2 and inhibited the migration, invasion and EMT in co-cultured CT26 cells through Wnt/ß-catenin signaling. Our results revealed that the downregulated FERMT2 gene during AD is prominently activated in CRC, which promotes its progression via Wnt/ß-catenin pathway.

[Contributions of impaired adult hippocampal neurogenesis to occurrence and development of diabetic encephalopathy].

Diabetic encephalopathy (DE) is one of the most common complications of diabetes mellitus (DM). Persistent hyperglycemia in DM patients may induce numerous pathophysiological changes, such as chronic inflammation, increased permeability of blood-brain barrier, impaired neurogenesis, and brain atrophy, which eventually impair cognitive function. The dentate gyrus (DG) of hippocampus is a crucial region for learning and memory, as well as adult neurogenesis in mammals. Recent studies have shown that adult hippocampal neurogenesis (AHN) exists throughout life and is decreased with age, whereas AHN is significantly impaired in DE. Therefore, numerous efforts are currently focused on exploring the mechanisms underlying cognitive impairment induced by AHN dysfunction in DE. Here, we summarize studies on the contributions of AHN disorders to the occurrence and development of DE and related mechanisms, in order to shed light on the prevention and treatment of DE.

Advanced glycation end products induce Aß1-42 deposition and cognitive decline through H19/miR-15b/BACE1 axis in diabetic encephalopathy.

OBJECTIVE: Diabetic encephalopathy (DE), a chronic complication of diabetes, is characterized by decline of cognitive function. The molecular mechanism of DE remains unclear. The purpose of this study is to evaluate the roles of advanced glycation end products (AGEs) in the pathogenesis of DE and investigate its underlying mechanisms in this process. METHODS: DE rats were developed by incorporating a high-fat diet and streptozotocin injection followed by the Morris Water Maze test. HT-22 cells were used to mimic the in vitro neuronal injuries of DE. Expression levels of long non-coding RNA H19, miR-15b and ß-site amyloid precursor protein cleaving enzyme 1 (BACE1) mRNA in the hippocampus of DE rats or HT-22 cells were detected by quantitative real-time polymerase chain reaction (qRT-PCR). The levels of BACE1 proteins were analyzed by western blotting or immunohistochemical staining. The contents of Aß1-42 in supernatant of the cell culture were analyzed by enzyme-linked immu-nosorbent assay (ELISA). The relationship between H19 or BACE1 and miR-15b was verified with dual-luciferase reporter assay. RESULTS: We found that the accumulation of Aß1-42 and the phosphorylation of Tau (Ser404) were increased in the hippocampus CA3 regionof DE rats. MiR-15b was downregulated while H19 and BACE1 were upregulated in the hippocampus CA3 regionof DE rats and AGEs-treated HT-22 cells. The expression of BACE1 protein was negatively regulated by miR-15b at the post-transcriptional level in HT-22 cells. In vivo, administration of miR-15b mimics by the intranasal delivery markedly decreased the BACE1 protein in hippocampal CA3 region and improved the cognitive decline in DE rats. Besides, the luciferase activity assay confirmed the binding site of miR-15b to both the 3'-untranslated region (3'-UTR) of BACE1 mRNA and H19. Then, miR-15b inhibitor reversed H19 knockdown-mediated decrease of Aß1-42 level in AGEs-treated HT-22 cells. CONCLUSION: These results suggested that AGEs induced Aß1-42 deposition andcognitive decline through H19/miR-15b/ BACE1 axis in DE.

Crosstalk Between Gut Microflora and Vitamin D Receptor SNPs Are Associated with the Risk of Amnestic Mild Cognitive Impairment in a Chinese Elderly Population.

BACKGROUND: The interactions between environmental factors and genetic variants have been implicated in the pathogenesis of Alzheimer's disease (AD). The altered gut microbiota (GM) and vitamin D deficiency are closely associated with the higher risk of AD. OBJECTIVE: This study was performed to evaluate whether the crosstalk between GM and single nucleotide polymorphisms (SNPs) of vitamin D receptor (VDR) or vitamin D binding protein (VDBP) have a link with the risk of amnestic mild cognitive impairment (aMCI) in the Chinese elderly population. METHODS: A total of 171 aMCI patients and 261 cognitive normal controls (NC) were enrolled in this study. Six tag SNPs of VDR and VDBP were genotyped by PCR-RFLP. The serum levels of vitamin D, Aß1-42, and p-tau (181P) were determined by using of ELISA kits. The alterations in the GM were analyzed by full-length 16S ribosomal RNA (rRNA) gene sequencing. RESULTS: The frequencies of AG genotype and A allele of VDR rs1544410 in aMCI group were significantly higher than that in NC group (genotype: p = 0.002, allele: p = 0.003). Patients with aMCI showed an abnormal GM composition compared with NC group. Interestingly, significant differences in GM composition were found between aMCI and NC group among individuals with AG genotype, as well as between individuals with AG and GG genotype of VDR rs1544410 among patients with aMCI. CONCLUSION: These results implicated that the crosstalk between gut microflora and vitamin D receptor variants are associated with the risk of aMCI in Chinese elderly population.

Correlation Between ApoE Gene Polymorphism and LEAD in Patients with T2DM That are of Han Nationality in Northern China.

To investigate the correlation between ApoE gene polymorphism and the risk of lower extremity arterial disease (LEAD) in T2DM patients of Han nationality in northern China. One hundred and fifty patients with T2DM and 150 patients with T2DM combined with LEAD were enrolled in the study and assigned to the control group and the case group, respectively. The results revealed that the number of epsilon 2 (ε2) genotype carriers in the case group was significantly lower than that in the control group (case vs control: 8.0% vs 15.4%), and the distribution of the ε2 allele frequency was similar to that of the genotype (case vs control: 4.0% vs 8.4%). A binary logistic regression analysis revealed that age, waist-to-hip ratio (WHR), and gender were risk factors for T2DM with LEAD and that the ApoE ε2 carriers was a protective factor (odds ratio [OR] 0.380; 95% confidence interval [CI] 0.162-0.892; P = .026). In male subjects, ε2 carriers were more common in the control group (case vs control:7.8% vs 24.1%), while epsilon 4 (ε4) carriers were more common in the case group (case vs control: 23.3% vs 8.6%); the distribution of frequency of ε2 and ε4 alleles was more common in the control group and the case group, respectively (case vs control: 3.9% vs 12.1%, 12.8% vs 5.2%). In male, age and WHR were risk factors for the disease, and being an ε2 carrier was a protective factor. Being an ApoE gene ε2 carrier is a protective factor for LEAD in male patients with T2DM that are of Han nationality in northern China.

Advanced Glycosylation End Products Induced Synaptic Deficits and Cognitive Decline Through ROS-JNK-p53/miR-34c/SYT1 Axis in Diabetic Encephalopathy.

BACKGROUND: miR-34c has been found to be implicated in the pathological process of Alzheimer's disease, diabetes, and its complications. OBJECTIVE: To investigate the underlying mechanisms of miR-34c in the pathogenesis of diabetic encephalopathy (DE). METHODS: Diabetes mellitus rats were developed by incorporating a high-fat diet and streptozotocin injection. Morris water maze test and novel object recognition test were used to assess the cognitive function of rats. Expression of miR-34c were detected by fluorescence in situ hybridization and qRT-PCR. Immunofluorescence and western blot were used to evaluate synaptotagmin 1 (SYT1) and AdipoR2 or other proteins. Golgi staining was performed to investigate dendritic spine density. RESULTS: The increased miR-34c induced by advanced glycation end-products (AGEs) was mediated by ROS-JNK-p53 pathway, but not ROS-Rb-E2F1 pathway, in hippocampus of DE rats or in HT-22 cells. miR-34c negatively regulated the expression of SYT1, but not AdipoR2, in hippocampal neurons. miR-34c inhibitor rescued the AGE-induced decrease in the density of dendritic spines in primary hippocampal neurons. Administration of AM34c by the intranasal delivery increased the hippocampus levels of SYT1 and ameliorated the cognitive function in DE rats. The serum levels of miR-34c were increased in patients with DE comparing with normal controls. CONCLUSION: These results demonstrated that AGE-induced oxidative stress mediated increase of miR-34c through ROS-JNK-p53 pathway, resulting in synaptic deficits and cognitive decline by targeting SYT1 in DE, and the miR-34c/SYT1 axis could be considered as a novel therapeutic target for DE patients.

Administration of miR-195 Inhibitor Enhances Memory Function Through Improving Synaptic Degradation and Mitochondrial Dysfunction of the Hippocampal Neurons in SAMP8 Mice.

BACKGROUND: Mitochondrial dysfunction is an early feature of Alzheimer's disease (AD) and miR-195 is involved in mitochondrial disorder through targeting MFN-2 protein in hippocampal neurons of AD. OBJECTIVE: To clarify if administration of miR-195 inhibitor could enhance the memory deficits through improving hippocampal neuron mitochondrial dysfunction in SAMP8 mice. METHODS: The expression of miR-195 was detected by RT-qPCR in primary hippocampal neurons and HT-22 cells treated with Aß1-42. Morris water maze (MWM) was used to assess the learning and memory function in SAMP8 mice administrated with antagomir-195. Transmission electron microscopy was employed to determine the morphological changes of synapses and mitochondria of hippocampus in SAMP8 mice. Mitochondrial respiration was measured using a high-resolution oxygraph. RESULTS: The expression of miR-195 were upregulated in the primary hippocampal neurons and HT-22 cells induced by Aß1-42. Inhibition of miR-195 ameliorated the mitochondrial dysfunction in HT-22 cells induced by Aß1-42, including mitochondrial morphologic damages, mitochondrial membrane potential, respiration function, and ATP production. Administration of antagomir-195 by the third ventricle injection markedly ameliorated the cognitive function, postsynaptic density thickness, length of synaptic active area, mitochondrial aspect ratio, and area in hippocampus of SAMP8 mice. Finally, antagomir-195 was able to promote an increase in the activity of respiratory chain complex CI and II in SAMP8 mice. CONCLUSION: This study demonstrated that miR-195 inhibitor ameliorated the cognitive impairment of AD mice by improving mitochondrial structure damages and dysfunction in the hippocampal neurons, which provide an experimental basis for further exploring the treatment strategy of AD.

Prevalence and risks of mild cognitive impairment of Chinese community-dwelling women aged above 60 years: A cross-sectional study.

Evidence has shown that risks of cognitive impairment differ between genders. This cross-sectional study sought to determine the prevalence of mild cognitive impairment (MCI) in Chinese community-dwelling women aged above 60 years and identify risks of MCI by multivariate logistic regression analysis. Totally, 1760 Chinese community-dwelling women entered the study. Cognitive function was assessed with Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA). MCI was diagnosed by Petersen's criteria. Sociodemographic information, past medical conditions, and age at menopause were screened. The primary study outcome was prevalence of MCI. MCI was diagnosed in 378 (21.5%) women. Older age was a significant risk of MCI (OR 1.621, 95%CI 1.386-1.894; P < 0.001). Low education was associated a 4-fold increase in the risk of MCI (OR 4.036, 95%CI 3.168-5.142). Furthermore, current depression was associated with 2.6-fold increase in the risk of MCI (OR 2.618, 95%CI 1.499-4.587, P = 0.001). Moreover, frequent physical exercise and more leisure and social time activities were associated with significantly reduced risks of MCI, while poor financial status was associated with a significantly increased risk of MCI. Slightly more than 20% of Chinese women aged above 60 years had MCI, and independent risks included older age, low education status, and current depression, highlighting the importance of screening for and removing or minimizing risks of MCI in this specific population.

Decreased lncRNA SNHG16 Accelerates Oxidative Stress Induced Pathological Angiogenesis in Human Retinal Microvascular Endothelial Cells by Regulating miR-195/mfn2 Axis.

BACKGROUND: This study was performed to identify the alterations of Long non-coding RNAs (lncRNAs) induced by oxidative stress and investigate the functional roles of SNHG16 in the pathological angiogenesis by human retinal microvascular endothelial cells (HMRECs). METHODS: The expression profiles of lncRNAs and mRNAs induced by oxidative stress were identified by RNA-Seq, and the dysregulation of 16 lncRNAs including SNHG16 was verified in H2O2-treated human umbilical vein endothelial cells (HUVECs). Luciferase reporter assay and RIP analysis were used to investigate the binding relationship of SNHG16 to miR-195. RESULTS: We confirmed that over-expression of SNGH16 attenuated H2O2-induced angiogenesis by HMRECs. In addition, SNHG16 was significantly decreased, whereas miR-195, a predictive target of SNHG16, was upregulated in H2O2;, HG, and AGE-treated HMRECs. The binding relationship of SNHG16 to miR-195 was subsequently verified by luciferase reporter assay and RIP analysis. SNHG16 cotransfection abolished miR-195-mediated repression on mitofusin 2 (mfn2) protein level and counteracted the inductive effect of miR-195 on angiogenesis by HMRECs. CONCLUSION: These results indicated that decreased SNHG16 accelerates oxidative stress-induced pathological angiogenesis in HMRECs by regulating the miR-195/mfn2 axis, providing a potential target for diabetic retinopathy (DR) therapy.

Association of Androgens and Gonadotropins with Amnestic Mild Cognitive Impairment and Probable Alzheimer's Disease in Chinese Elderly Men.

BACKGROUND: Age-related hormone changes play important roles in cognitive decline in older men, and apolipoprotein E ɛ4 (APOEɛ4) is a risk factor for Alzheimer's disease (AD). OBJECTIVE: This study aimed to investigate the interactive role of androgen decline and APOEɛ4 genotype in the pathogenesis of amnestic mild cognitive impairment (aMCI) and AD. METHODS: In total, 576 elderly men over 65 years old from communities in Shijiazhuang were enrolled in this study, including 243 with normal cognition (NC), 271 with aMCI, and 62 with probable AD. Cognitive function was evaluated with a battery of neuropsychological tests. The serum levels of androgen and gonadotropin were detected by ELISA and chemiluminescence immunoassay. RESULTS: The levels of free testosterone (FT) and dihydrotestosterone (DHT) were lower in the aMCI group (p < 0.05), and even lower in the AD group (p < 0.001), but the levels of follicle stimulating hormone (FSH) and luteinizing hormone (LH)were higher in AD group (p < 0.01), comparing with that in NC or aMCI group. The interaction of lower FT or DHT levels with APOEɛ4 had a risk role in global cognitive impairment (p < 0.05). The area under the curve (AUC) of the ROC curve for predicting aMCI by serum FT levels was 0.745. CONCLUSION: These results indicated that the interaction of androgen decline and APOEɛ4 genotype play a role in aMCI and AD. Serum FT levels have a predictive value for aMCI and might be a potential biomarker for prodromal AD.

[Research progress on the epigenetic mechanisms of inverse relationship between Alzheimer's disease and cancer onset].

Alzheimer's disease (AD) is currently the most prevalent neurodegenerative disease in the aging population. It is characterized by massive deposition of extracellular ß-amyloid peptide and formation of intracellular neurofibrillary tangles. Cancer is also an age-related disease. Some epidemiological studies have shown an inverse relationship between AD and the onset of various types of cancers, that is, the risk of cancer in patients with AD is reduced, and vice versa. Epigenetic mechanisms play important roles in the development of AD and cancer. In this article, we will review the recent research advances on the epigenetic mechanisms of AD and cancer onset, and provide new ideas for rethinking the relevance of AD and cancer with a "holistic concept".

Increased miR-34c mediates synaptic deficits by targeting synaptotagmin 1 through ROS-JNK-p53 pathway in Alzheimer's Disease.

Alzheimer's disease (AD) and cancer have inverse relationship in many aspects. Some tumor suppressors, including miR-34c, are decreased in cancer but increased in AD. The upstream regulatory pathways and the downstream mechanisms of miR-34c in AD remain to be investigated. The expression of miR-34c was detected by RT-qPCR in oxidative stressed neurons, hippocampus of SAMP8 mice, or serum of patients with amnestic mild cognitive impairment (aMCI). Dual luciferase assay was performed to confirm the binding sites of miR-34c in its target mRNA. The Morris water maze (MWM) was used to evaluate learning and memory in SAMP8 mice administrated with miR-34c antagomir (AM34c). Golgi staining was used to evaluate the synaptic function and structure. The dramatically increased miR-34c was mediated by ROS-JNK-p53 pathway and negatively regulated synaptotagmin 1 (SYT1) expression by targeting the 3'-untranslated region (3'-UTR) of syt1 in AD. The expression of SYT1 protein was reduced by over expression of miR-34c in the HT-22 cells and vice versa. Administration of AM34c by the third ventricle injection or intranasal delivery markedly increased the brain levels of SYT1 and ameliorated the cognitive function in SAMP8 mice. The serum miR-34c was significantly increased in patients with aMCI and might be a predictive biomarker for diagnosis of aMCI. These results indicated that increased miR-34c mediated synaptic and memory deficits by targeting SYT1 through ROS-JNK-p53 pathway and the miR-34c/SYT1 pathway could be considered as a promising novel therapeutic target for patients with AD.

Evaluation of the diagnostic value of peripheral BDNF levels for Alzheimer's disease and mild cognitive impairment: results of a meta-analysis.

Deregulation of brain-derived neurotrophic factor (BDNF) is a possible contributor to the pathology and symptoms of Alzheimer's disease (AD). Most studies support an association between the dysfunction of BDNF and the pathogenesis of AD. This study aimed to evaluate the diagnostic value of peripheral BDNF levels in patients with AD and mild cognitive impairment (MCI) using meta-analytic techniques. A systematic search of the MEDLINE, EMBASE, ISI Web of Science, and the Cochrane Central database was performed and 34 eligible articles were identified for inclusion in the meta-analysis. Random-effects meta-analysis showed that AD patients had significantly decreased levels of peripheral BDNF compared with healthy control (HC) subjects (Hedges' g = - 0.725, 95% CI = -1.06 to - 0.39, p < 0.01). MCI patients showed a same trend with decreased BDNF levels compared with HC subjects (Hedges' g = - 0.296, 95% CI = - 0.57 to - 0.02, p < 0.01). Significant differences were found between AD and MCI subjects in peripheral BDNF levels (Hedges' g = - 0.462, 95% CI = - 0.95 to 0.03, p < 0.01). However, the ROC curve analysis revealed that the peripheral BDNF levels may not be an optimal biomarker potentially for AD and MCI diagnosis with a lower AUC (AD: 0.707; MCI: 0.573), less sensitivity (AD: 66.67%; MCI: 50.00%) and poor specificity (AD: 93.33%; MCI: 83.33%). These results suggested that AD or MCI is accompanied by reduction of peripheral BDNF, but the levels of circulating BDNF may not be suitable as a diagnostic marker for AD and MCI.

Decreased miR-132 plays a crucial role in diabetic encephalopathy by regulating the GSK-3ß/Tau pathway.

Diabetic encephalopathy (DE) is a global concern and Gordian knot worldwide. miRNA-132 (miR-132) is a class of negative gene regulators that promote diabetic pathologic mechanisms and its complications. However, the molecular mechanisms of miR-132 in DE are elusive, thus an alternative therapeutic strategy is urgently in demand. The present study explored the protective effect and the underlying mechanism of miR-132 on DE via the GSK-ß/Tau signaling pathway. Experimentally, a type 2 DM rat model was developed by incorporating a high-fat diet and streptozotocin injection. Further, the DE model was screened via the Morris Water Maze test. Primary hippocampal neurons and HT-22 cells were used for in vitro analysis. We found that hyperglycemia exacerbates cognitive impairment in T2DM rats. When we isolated the primary hippocampus neurons, the expression of miR-132 RNA was low in both the DE hippocampus and primary neurons. GSK-3ß and Tau 404 were highly expressed in injured HT-22 cells and diabetic hippocampal tissues. miR-132 downregulated the expression of GSK-3ß. Besides, a binding and colocalized relationship between GSK3ß and Tau was also reported. These findings suggest that miR-132 exerts protective effects from DE injury by repressing GSK-3ß expression and alleviating Tau hyperphosphorylation in HT-22 cells and hippocampus tissues.