Tu-Xian decoction (TXD), a traditional Chinese medicine (TCM) formula, has been frequently administered to manage diabetic cognitive impairment (DCI). Despite its widespread use, the mechanisms underlying TXD's protective effects on DCI have yet to be fully elucidated. As a significant regulator in neurodegenerative conditions, death-associated protein kinase-1 (DAPK-1) serves as a focus for understanding the action of TXD. This study was designed to whether TXD mediates its beneficial outcomes by inhibiting DAPK-1. To this end, a diabetic model was established using Sprague-Dawley (SD) rats through a high-fat, high-sugar (HFHS) diet regimen, followed by streptozotocin (STZ) injection. The experimental cohort was stratified into six groups: Control, Diabetic, TC-DAPK6, high-dose TXD, medium-dose TXD, and low-dose TXD groups. Following a 12-week treatment period, various assessments-including blood glucose levels, body weight measurements, Morris water maze (MWM) testing for cognitive function, brain magnetic resonance imaging (MRI), and histological analyses using hematoxylin-eosin (H&E), and Nissl staining-were conducted. Protein expression in the hippocampus was quantified through Western blotting analysis. The results revealed that TXD significantly improved spatial learning and memory abilities, and preserved hippocampal structure in diabetic rats. Importantly, TXD administration led to a down-regulation of proteins indicative of neurological damage and suppressed DAPK-1 activity within the hippocampal region. These results underscore TXD's potential in mitigating DCIvia DAPK-1 inhibition, positioning it as a viable therapeutic candidate for addressing this condition. Further investigation into TXD's molecular mechanisms may elucidate new pathways for the treatment of DCI.
Animals ; Rats ; Brain/metabolism* ; Cognitive Dysfunction/drug therapy* ; Diabetes Mellitus, Experimental/metabolism* ; Hippocampus ; Rats, Sprague-Dawley

Chronic stress is generally accepted as the main risk factor in the development of cognitive decline; however, the underlying mechanisms remain unclear. Previous data have demonstrated that the levels of homocysteine (Hcy) are significantly elevated in the plasma of stressed animals, which suggests that Hcy is associated with stress and cognitive decline. To test this hypothesis, we analyzed the cognitive function, plasma concentrations of Hcy, and brain-derived neurotropic factor (BDNF) levels in rats undergoing chronic unpredicted mild stress (CUMS). The results showed that decreased cognitive behavioral performance and decreased BDNF transcription and protein expression were correlated with hyperhomocysteinemia (HHcy) levels in stressed rats. Diet-induced HHcy mimicked the cognitive decline and BDNF downregulation in the same manner as CUMS, while Hcy reduction (by means of vitamin B complex supplements) alleviated the cognitive deficits and BDNF reduction in CUMS rats. Furthermore, we also found that both stress and HHcy disturbed the DNA methylation process in the brain and induced DNA hypermethylation in the BDNF promoter. In contrast, control of Hcy blocked BDNF promoter methylation and upregulated BDNF levels in the brain. These results imply the possibility of a causal role of Hcy in stress-induced cognitive decline. We also used ten-eleven translocation (TET1), an enzyme that induces DNA demethylation, to verify the involvement of Hcy and DNA methylation in the regulation of BDNF expression and the development of stress-related cognitive decline. The data showed that TET1-expressing viral injection into the hippocampus inhibited BDNF promoter methylation and significantly mitigated the cognitive decline in HHcy rats. Taken together, novel evidence from the present study suggests that Hcy is likely involved in chronic stress-induced BDNF reduction and related cognitive deficits. In addition, the negative side-effects of HHcy may be associated with Hcy-induced DNA hypermethylation in the BDNF promoter. The results also suggest the possibility of Hcy as a target for therapy and the potential value of vitamin B intake in preventing stress-induced cognitive decline.
Animals ; Brain-Derived Neurotrophic Factor/metabolism* ; Cognitive Dysfunction/complications* ; DNA Methylation ; Homocysteine/metabolism* ; Hyperhomocysteinemia/metabolism* ; Rats ; Stress, Psychological/physiopathology*

Alzheimer's disease (AD) is the most common type of dementia. Almost two-thirds of patients with AD are female. The reason for the higher susceptibility to AD onset in women is unclear. However, hormone changes during the menopausal transition are known to be associated with AD. Most recently, we reported that follicle-stimulating hormone (FSH) promotes AD pathology and enhances cognitive dysfunctions via activating the CCAAT-enhancer-binding protein (C/EBPβ)/asparagine endopeptidase (AEP) pathway. This review summarizes our current understanding of the crucial role of the C/EBPβ/AEP pathway in driving AD pathogenesis by cleaving multiple critical AD players, including APP and Tau, explaining the roles and the mechanisms of FSH in increasing the susceptibility to AD in postmenopausal females. The FSH-C/EBPβ/AEP pathway may serve as a novel therapeutic target for the treatment of AD.
Female ; Humans ; Male ; Alzheimer Disease/pathology* ; CCAAT-Enhancer-Binding Protein-beta/metabolism* ; Cognitive Dysfunction/metabolism* ; Signal Transduction ; Follicle Stimulating Hormone

Animals ; Cognitive Dysfunction ; metabolism ; Cystatin C ; pharmacology ; Hippocampus ; drug effects ; Insulin Resistance ; physiology ; Neurons ; drug effects ; Rats ; Rodentia

The aim of the present study was to explore the correlation between ptk2b/PTK2B (protein tyrosine kinase 2 beta, a ptk2b-encoded protein) and the level of low density lipoprotein receptor-related protein-1 (LRP-1), as well as to uncover the relationship between the changes in beta amyloid protein (Aβ) levels in blood and brain and the expression of ptk2b in Aβ-induced cognitive dysfunction mice. A total of 64 3-month-old C57BL/6J mice were divided randomly into the experimental group and control group. All mice underwent the intracerebroventricular (i.c.v.) intubation. Mice in the experimental group received the i.c.v. infusion of oligomeric Aβ
Alzheimer Disease ; Amyloid beta-Peptides/metabolism* ; Animals ; Brain ; Cognitive Dysfunction/chemically induced* ; Disease Models, Animal ; Focal Adhesion Kinase 2 ; Hippocampus/metabolism* ; Mice ; Mice, Inbred C57BL ; Peptide Fragments

Amyloid beta (Aβ) plaques are one of the hallmarks of Alzheimer's disease (AD). However, currently available anti-amyloid therapies fail to show effectiveness in the treatment of AD in humans. It has been found that there are different types of Aβ plaque (diffuse and focal types) in the postmortem human brain. In this study, we aimed to investigate the correlations among different types of Aβ plaque and AD-related neuropathological and cognitive changes based on a postmortem human brain bank in China. The results indicated that focal plaques, but not diffuse plaques, significantly increased with age in the human hippocampus. We also found that the number of focal plaques was positively correlated with the severity of AD-related neuropathological changes (measured by the "ABC" scoring system) and cognitive decline (measured by the Everyday Cognitive Insider Questionnaire). Furthermore, most of the focal plaques were co-localized with neuritic plaques (identified by Bielschowsky silver staining) and accompanied by microglial and other inflammatory cells. Our findings suggest the potential of using focal-type but not general Aβ plaques as biomarkers for the neuropathological evaluation of AD.
Alzheimer Disease/pathology* ; Amyloid beta-Peptides/metabolism* ; Amyloid beta-Protein Precursor ; Brain/pathology* ; Cognitive Dysfunction/pathology* ; Hippocampus/metabolism* ; Humans ; Neuroinflammatory Diseases ; Plaque, Amyloid/pathology*

Tripterygium glycosides liposome(TPGL) were prepared by thin film-dispersion method, which were optimized accor-ding to their morphological structures, average particle size and encapsulation rate. The measured particle size was(137.39±2.28) nm, and the encapsulation rate was 88.33%±1.82%. The mouse model of central nervous system inflammation was established by stereotaxic injection of lipopolysaccharide(LPS). TPGL and tripterygium glycosides(TPG) were administered intranasally for 21 days. The effects of intranasal administration of TPG and TPGL on behavioral cognitive impairment of mice due to LPS-induced central ner-vous system inflammation were estimated by animal behavioral tests, hematoxylin-eosin(HE) staining of hippocampus, real-time quantitative polymerase chain reaction(RT-qPCR) and immunofluorescence. Compared with TPG, TPGL caused less damage to the nasal mucosa, olfactory bulb, liver and kidney of mice administered intranasally. The behavioral performance of treated mice was significantly improved in water maze, Y maze and nesting experiment. Neuronal cell damage was reduced, and the expression levels of inflammation and apoptosis related genes [tumor necrosis factor-α(TNF-α), interleukin-1β(IL-1β), BCL2-associated X(Bax), etc.] and glial activation markers [ionized calcium binding adaptor molecule 1(IBA1) and glial fibrillary acidic protein(GFAP)] were decreased. These results indicated that liposome technique combined with nasal delivery alleviated the toxic side effects of TPG, and also significantly ameliorated the cognitive impairment of mice induced by central nervous system inflammation.
Mice ; Animals ; Tripterygium ; Liposomes ; Glycosides/therapeutic use* ; Administration, Intranasal ; Lipopolysaccharides ; Central Nervous System ; Cognitive Dysfunction/drug therapy* ; Inflammation/metabolism* ; Tumor Necrosis Factor-alpha/metabolism* ; Cardiac Glycosides

OBJECTIVETo study the effects of electroacupuncture (EA) on the changes of behavior after ketamine anesthesia, and changes of serum antibodies against beta-amyloid (Abeta) and Abeta protein in the hippocampus of aged rats, thus exploring the effects of EA on the cognitive dysfunction.

METHODSThirty 14-month old SD rats were randomly divided into 3 groups, i. e. , the control group (Group A), the ketamine anesthesia group (Group B), and the EA+ketamine anesthesia group (Group C), 10 in each group. 50 mg/kg katemine was intraperitoneally injected to rats in Group B and Group C, once daily for 7 successive days. EA was performed to rats in Group C from the 1st day of the experiment after rats awoke completely from anesthesia, twice daily for 7 successive days. Changes of the ratio of the swim time in the original platform quadrant to the total swim time and the escape latency phase were observed by Morris water maze. The peripheral blood was withdrawn by the end of the experiment. Serum anti-Abeta antibody contents were detected using enzyme-linked immunosorbent assay (ELISA). The expressions of Abeta in the hippocampus were detected using Westen blot.

RESULTSLong-term application of ketamine could lower aged rats' cognitive function. In the navigation test, the escape latency phase of rats in Group B was significantly prolonged ( P < 0.01) . On the 7th day of the experiment, the serum level of anti-Abeta antibodies was lower in Group B than in Group A (P < 0.05), while the serum level of anti-Abeta antibodies was significantly higher in Group C than in Group B (P < 0.01). On the 7th day of the experiment, the expression of Abeta in the hippocampus was higher in Group B than in Group A (P < 0.05).

CONCLUSIONEA could increase the contents of anti-Abeta antibodies in aged rats with ketamine anesthesia, decrease the expression of Abeta in the hippocampus, alleviate the deposition of Abeta, thus improving rats' cognitive dysfunction.

Amyloid beta-Peptides ; immunology ; Anesthesia ; adverse effects ; Animals ; Antibodies ; blood ; Cognitive Dysfunction ; therapy ; Electroacupuncture ; Female ; Hippocampus ; metabolism ; Ketamine ; adverse effects ; Male ; Maze Learning ; Rats ; Rats, Sprague-Dawley

Objective To explore the effect of dexmedetomidine(Dex)on sevoflurane-induced cognitive impairment in neonatal rats through Wnt signaling pathway. Methods Sixty 7-day-old SD rats were assigned into five groups:control group(without any intervention),Dex group(intraperitoneal injection of 25 μg/kg Dex),sevoflurane group(3% sevoflurane treatment for 4 hours),sevoflurane+Dex group(inhalation of 3% sevoflurane after injection of 25 μg/kg Dex for 4 hours),and sevoflurane+Dex+Wnt inhibitor group(Wnt inhibitor XAV393 and 25 μg/kg Dex were injected and 3% sevoflurane was inhaled for 4 hours).Three weeks later,Morris water maze was used to detect the cognitive function;TdT-mediated dUTP nick end labeling(TUNEL)staining was performed to detect the apoptosis of hippocampal neurons;neuronal nuclei (NeuN) staining was conducted to detect the survival of hippocampal neurons;Western blot was carried out to detect the expression of apoptosis-related proteins.The expression of the factors involved in Wnt/GSK-3β/β-catenin signaling pathway was detected by fluorescence quantitative polymerase chain reaction,and Western blot. Results Compared with the control group,there was no significant difference in the escape latency of Dex group(t=0.304,P=0.768);the escape latency in sevoflurane group(t=5.823,P=0.002),sevoflurane+Dex group(t=3.188,P=0.010),and sevoflurane+Dex+Wnt inhibitor group(t=5.784,P=0.002)was significantly prolonged.Compared with that in the sevoflurane group,the escape latency in sevoflurane+Dex group(t=3.646,P=0.005)was significantly shortened.Compared with that in sevoflurane+Dex group,the escape latency in sevoflurane+Dex+Wnt inhibitor group(t=3.296,P=0.008)was prolonged.Compared with that in the control group,the times of crossing platform in sevoflurane group(t=5.179, P=0.004),sevoflurane+Dex group(t=2.309,P=0.043),and sevoflurane+Dex+Wnt inhibitor group(t=3.871, P=0.003)decreased.Compared with that in sevoflurane group,the times of crossing platform in sevoflurane+Dex group(t=3.296,P=0.008)significantly increased.Compared with that in sevoflurane+Dex group,the times of crossing platform in sevoflurane+Dex+Wnt inhibitor group(t=2.361, P=0.041)reduced.Compared with the control group,there was no significant difference in the number of apoptotic cells in Dex group(t=1.920,P=0.127),and the number of apoptotic cells in sevoflurane group,sevoflurane+Dex group,and sevoflurane+Dex+Wnt inhibitor group increased by 16%(t=13.436,P=0.002),5%(t=7.752, P=0.001),and 11.5%(t=12.612,P=0.002),respectively.Compared with that in the sevoflurane group,the number of apoptotic cells in sevoflurane+Dex group and sevoflurane+Dex+Wnt inhibitor group decreased by 11%(t=8.521,P=0.002)and 5.5%(t=3.123,P=0.036),respectively.Compared with that in the sevoflurane+Dex group,the number of apoptotic cells in sevoflurane+Dex+Wnt inhibitor group increased by 6.5%(t=6.250,P=0.003).Compared with that in the control group,the number of positive cells in 0.15 mm
Animals ; Animals, Newborn ; Cognitive Dysfunction/chemically induced* ; Dexmedetomidine/pharmacology* ; Glycogen Synthase Kinase 3 beta ; Rats ; Rats, Sprague-Dawley ; Sevoflurane/toxicity* ; Wnt Signaling Pathway ; beta Catenin/metabolism*

OBJECTIVE: To evaluate the effects of ferroptosis in hippocampal neurons on cognitive dysfunction in rats with sepsis-associated encephalopathy (SAE) and its potential molecular mechanisms. METHODS: (1) Screening experiment of SAE modeling conditions: 42 healthy male Sprague-Dawley (SD) rats were divided into normal saline (NS) control group (n = 6) and lipopolysaccharide (LPS) 5, 15, 30 mg/kg groups (each n = 12) according to the random number table method. The SAE modeling conditions were determined by survival and the changes in mean arterial pressure (MAP) and heart rate (HR) within 72 hours, the percentage of stiffness status, the levels of serum inflammatory factors including interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), neuron specific enolase (NSE, a marker of neuronal injury), serum iron and lactic acid (Lac) contents, and the morphological changes in CA1 of hippocampus after 72 hours. (2) Deferoxamine (Def) intervention experiment: according to the results of screening experiments, 28 healthy male SD rats were divided into NS control group (n = 8), SAE group (n = 10) and Def+SAE group (n = 10) according to the random number table method. In the Def+SAE group, 100 mg/kg Def was injected intraperitoneally 12 hours before the modeling, once every 12 hours, with a total of 7 times; the rats in the NS control group and SAE group were injected with the same amount of NS. Then the cognitive function of rats was evaluated by fear conditioning test for the percentage of stiffness status; serum IL-6, TNF-α and NSE levels were determined by enzyme-linked immunosorbent assay (ELISA); the levels of serum Lac, serum iron and hippocampal malondialdehyde (MDA) and iron contents were determined by chemical colorimetric; the protein expressions of nuclear factor E2 related factor 2 (Nrf2), glutathione peroxidase 4 (GPX4) and NAPDH oxidase 1 (NOX1) in hippocampus were determined by Western Blot; morphological changes in hippocampal CA1 were observed after hematoxylin and eosin (HE) staining. RESULTS: (1) Compared with the NS control group, intraperitoneal injection of 15 mg/kg LPS could significantly reduce the MAP and HR as time prolonged, and the reduction was most significant at 72 hours. The 72-hour survival rate was significantly reduced and cognitive function was impaired. The levels of serum IL-6, TNF-α, Lac and NSE were increased while the serum iron content was decreased significantly. The morphology of vertebral cells in hippocampal CA1 was irregular and some of the cells were obviously vacuolated. In the LPS 5 mg/kg group, there were no significant changes in vital signs, inflammation, organ function or cognitive dysfunction, while the symptoms of septic shock were apparent in the LPS 30 mg/kg group. Therefore, SAE model was reproduced by intraperitoneal injection of 15 mg/kg LPS for 72 hours. (2) Compared with the NS control group, the percentage of stiffness in the SAE group was significantly reduced. The levels of serum IL-6, NSE and hippocampal MDA, iron were significantly increased. The serum iron contents and hippocampal Nrf2 and GPX4 protein expressions were significantly reduced, while the hippocampal NOX1 protein expression was significantly increased. The morphology of vertebral cells in hippocampal CA1 was irregular and the cytoplasm was deeply stained. The results indicated that the level of oxidative stress in the hippocampus of SAE rats was increased, the neuron degenerations were obvious, and the cognitive function of rats were impaired. Compared with the SAE group, the percentage of stiffness in the Def+SAE group was significantly increased [(63.4±6.4)% vs. (47.6±6.0)%, P < 0.05]. The levels of serum IL-6, NSE, iron and hippocampal MDA, iron were significantly reduced [serum IL-6 (ng/L): 73.14±8.31 vs. 99.86±12.37, serum NSE (μg/L): 3.67±0.51 vs. 5.92±0.79, serum iron (mg/L): 68.43±8.12 vs. 134.60±15.63, hippocampal MDA (mol/g): 4.62±0.90 vs. 6.62±0.84, hippocampal iron (μg/g): 155.32±17.86 vs. 221.54±27.54, all P < 0.05]. The hippocampal protein expressions of Nrf2 and GPX4 were significantly increased [Nrf2/β-actin: 0.41±0.07 vs. 0.18±0.03, GPX4/β-actin: 0.74±0.09 vs. 0.40±0.06, all P < 0.05] while the hippocampal NOX1 protein expression was significantly reduced (NOX1/β-actin: 0.62±0.08 vs. 1.11±0.16, P < 0.05). The vertebral cells was significantly improved as compared with the SAE group. These findings showed that the oxidative stress level in hippocampus of the Def+SAE group was reduced, neuron degeneration was significantly alleviated, and the cognitive function of the rats was significantly improved. CONCLUSIONS The cognitive function of rats with SAE was significantly impaired, the hippocampal neurons were obviously damaged and ferroptosis was increased. Def pretreatment could significantly reduce iron deposition and ferroptosis in hippocampal neurons of SAE rats and improve cognitive dysfunction, which may be related to activation of Nrf2/GPX4 signaling pathway.
Animals ; Cognitive Dysfunction ; Ferroptosis ; Hippocampus ; Male ; NF-E2-Related Factor 2/metabolism* ; Neurons ; Rats ; Rats, Sprague-Dawley ; Sepsis ; Sepsis-Associated Encephalopathy ; Signal Transduction ; Tumor Necrosis Factor-alpha