This study aims to investigate the effect of Congrong San(CRS) on endoplasmic reticulum stress-induced neuroinflammation in the rat model of Aβ_(1-42)-induced Alzheimer's disease(AD). Sixty male Sprague-Dawley rats(2 months old) were randomized into blank(CON), model(MOD), low-dose Congrong San(L-CRS), medium-dose Congrong San(M-CRS), high-dose Congrong San(H-CRS), and memantine hydrochloride(MJG) groups. The Morris water maze test was carried out to examine the learning and memory abilities of rats in each group. Hematoxylin-eosin staining and Nissl staining were employed to observe the morphology and number of CA1 neurons in the hippocampus of rats in each group. The morphology and structure of the endoplasmic reticulum in the hippocampus were observed by transmission electron microscopy. The immunofluorescence assay was employed to detect the expression of 78 kDa glucose-regulated protein(GRP78) in the hippocampus. Western blot was employed to determine the expression of apoptosis-associated speck-like protein containing a CARD(ASC), cysteinyl aspartate-specific proteinase(caspase-1), interleukin-18(IL-18), interleukin-1β(IL-1β), GRP78, and pathway proteins including protein kinase RNA-like endoplasmic reticulum kinase(PERK), phosphorylated PERK(p-PERK), C/EBP homologous protein(CHOP), and NOD-like receptor pyrin domain-containing protein 3(NLRP3) in the rat hippocampus. Compared with the MOD group, the M-CRS and H-CRS groups showed improved learning and memory abilities, reduced neuron losses in the hippocampus, alleviated endoplasmic reticulum stress, inhibited PERK-CHOP-NLRP3 pathway, and lowered levels of IL-1β, IL-6, and tumor necrosis factor-alpha(TNF-α). The results suggest that CRS can alleviate cognitive impairment and hippocampal neuron damage and reduce neuroinflammation in AD rats by alleviating endoplasmic reticulum stress to inhibit the activation of NLRP3 inflammasomes.
Animals ; Endoplasmic Reticulum Stress/drug effects* ; Male ; Alzheimer Disease/psychology* ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; Rats, Sprague-Dawley ; Rats ; Inflammasomes/genetics* ; Drugs, Chinese Herbal/administration & dosage* ; Cognitive Dysfunction/metabolism* ; Disease Models, Animal ; Hippocampus/drug effects* ; Humans ; Neuroinflammatory Diseases/drug therapy*

This study aimed to investigate the effects of caffeoylquinic acids from Erigeron breviscapus(EBCQA) on cognitive impairment and mitochondrial dysfunction in Alzheimer's disease(AD), and to explore its underlying mechanisms. The impacts of EBCQA on paralysis, β-amyloid(Aβ) oligomerization, and mRNA expression of mitophagy-related genes [PTEN-induced putative kinase 1(PINK1) homolog-encoding gene pink-1, Parkin homolog-encoding gene pdr-1, Bcl-2 interacting coiled-coil protein 1(Beclin 1) homolog-encoding gene bec-1, microtubule-associated protein 1 light chain 3(LC3) homolog-encoding gene lgg-1, autophagic adapter protein 62(p62) homolog-encoding gene sqst-1] were examined in the AD Caenorhabditis elegans CL4176 model, along with mitochondrial functions including adenosine triphosphate(ATP) content, enzyme activities of mitochondrial respiratory chain complexes Ⅰ,Ⅲ, and Ⅳ, and mitochondrial membrane potential. Additionally, the effects of EBCQA on the green fluorescent protein(GFP)/red fluorescent protein from Discosoma sp.(DsRed) ratio, the expression of phosphatidylethanolamine-modified and GFP-labeled LGG-1(PE-GFP::LGG-1)/GFP-labeled LGG-1(GFP::LGG-1), and GFP-labeled SQST-1(GFP::SQST-1) proteins were investigated in transgenic C. elegans strains. The effect of EBCQA on paralysis was further evaluated after RNA interference(RNAi)-mediated suppression of the pink-1 and pdr-1 genes in CL4176 strain. An AD rat model was established through intraperitoneal injection of D-galactose and intragastric administration of aluminum trichloride. The effects of β-nicotinamide mononucleotide(NMN) and EBCQA on learning and memory ability, neuronal morphology, mitophagy occurrence, mitophagy-related protein expression(PINK1, Parkin, Beclin 1, LC3-Ⅱ/LC3-Ⅰ, p62), and mitochondrial functions(ATP content; enzyme activities of mitochondrial respiratory chain complexes Ⅰ, Ⅲ, and Ⅳ; mitochondrial membrane potential) were investigated in this AD rat model. The results showed that EBCQA delayed paralysis onset in the CL4176 strain, reduced Aβ oligomer formation, and upregulated the mRNA expression levels of lgg-1, bec-1, pink-1, and pdr-1, while downregulating sqst-1 mRNA expression. EBCQA also enhanced ATP content, mitochondrial membrane potential, and the activities of mitochondrial respiratory chain complexes Ⅰ, Ⅲ, and Ⅳ. Furthermore, EBCQA improved the PE-GFP::LGG-1/GFP::LGG-1 ratio, reduced GFP::SQST-1 expression, and decreased the GFP/DsRed ratio. Notably, the ability of EBCQA to delay paralysis was significantly reduced following RNAi-mediated suppression of pink-1 and pdr-1 in CL4176 strain. In AD rats, the administration of NMN or EBCQA significantly improved learning and memory, restored neuronal morphology in the hippocampus, increased autophagosome numbers, and upregulated the expression of PINK1, Parkin, Beclin 1, and the LC3-Ⅱ/LC3-Ⅰ ratio, while reducing p62 expression. Additionally, the treatment with NMN or EBCQA both elevated ATP content, mitochondrial respiratory chain complex Ⅰ, Ⅲ, and Ⅳ activities, and mitochondrial membrane potential in the hippocampus. The above findings indicate that EBCQA improves cognitive impairment and mitochondrial dysfunction in AD, possibly through activation of PINK1/Parkin-mediated mitophagy.
Animals ; Alzheimer Disease/psychology* ; Mitophagy/drug effects* ; Mitochondria/genetics* ; Caenorhabditis elegans/metabolism* ; Ubiquitin-Protein Ligases/genetics* ; Cognitive Dysfunction/physiopathology* ; Rats ; Protein Kinases/genetics* ; Humans ; Male ; Disease Models, Animal ; Caenorhabditis elegans Proteins/genetics* ; Drugs, Chinese Herbal/administration & dosage*

This study aims to explore the effects and mechanisms of 4'-O-methylbavachalcone(MeBavaC), an active compound from Psoraleae Fructus, in regulating white matter neuroinflammation to improve vascular cognitive impairment. Male Sprague-Dawley(SD) rats were randomly divided into four groups: sham group, model group, high-dose MeBavaC group(14 mg·kg~(-1)), and low-dose MeBavaC group(7 mg·kg~(-1)). The rat model of chronic cerebral hypoperfusion(CCH) was established using bilateral common carotid artery occlusion. The Morris water maze test was performed to evaluate the learning and memory abilities of the rats. Luxol fast blue staining, Nissl staining, immunofluorescence, immunohistochemistry, and transmission electron microscopy were utilized to observe the morphology and ultrastructure of the white matter myelin sheaths, axon integrity, the morphology and number of hippocampal neurons, and the loss and activation of glial cells in the white matter. Transcriptome analysis was performed to explore the potential mechanisms of white matter injury induced by CCH. Western blot and quantitative real-time polymerase chain reaction(qRT-PCR) assays were conducted to measure the expression levels of NOD-like receptor protein 3(NLRP3), absent in melanoma 2(AIM2), gasdermin D(GSDMD), cysteinyl aspartate-specific proteinase-1(caspase-1), interleukin-18(IL-18), interleukin-1β(IL-1β), erythropoietin(EPO), nuclear factor erythroid 2-related factor 2(Nrf2), and heme oxygenase-1(HO-1) in the white matter of rats. The results showed that compared with the model group, MeBavaC significantly improved the learning and memory abilities of rats with CCH, improved the damage of white matter myelin sheath, maintained axonal integrity, reduced the loss of hippocampal neurons and oligodendrocytes in the white matter, inhibited the activation of microglia and the proliferation of astrocytes in the white matter, and suppressed the NLRP3/AIM2/caspase-1/GSDMD pathway. The expression levels of inflammatory cytokines IL-1β and IL-18 were significantly reduced, while EPO expression and the expression of Nrf2/HO-1 antioxidant pathway were notably elevated. In conclusion, MeBavaC can alleviate cognitive impairment in rats with CCH and suppress neuroinflammation in cerebral white matter. The mechanism of action may involve activation of EPO activity, promotion of endogenous antioxidant pathways, and inhibition of neuroinflammation in the white matter. This study suggests that MeBavaC exhibits antioxidant and anti-neuroinflammatory effects, showing potential application in improving cognitive dysfunction.
Animals ; Male ; Rats, Sprague-Dawley ; NF-E2-Related Factor 2/immunology* ; Rats ; Chalcones/administration & dosage* ; Cognitive Dysfunction/metabolism* ; Signal Transduction/drug effects* ; Neuroinflammatory Diseases/drug therapy* ; Heme Oxygenase-1/metabolism* ; Humans ; Heme Oxygenase (Decyclizing)/genetics*

Alzheimer's disease (AD) poses one of the most urgent medical challenges in the 21st century as it affects millions of people. Unfortunately, the etiopathogenesis of AD is not yet fully understood and the current pharmacotherapy options are somewhat limited. Here, we report a novel inhibitor, Compound 44, for targeting cholinesterases, amyloid-β (Aβ) aggregation, and glycogen synthase kinase 3β (GSK-3β) simultaneously with the aim of achieving symptomatic relief and disease modification in AD therapy. We found that Compound 44 had good inhibitory effects on all intended targets with IC₅₀s of submicromolar or better, significant neuroprotective effects in cell models, and beneficial improvement of cognitive deficits in the triple transgenic AD (3 × Tg AD) mouse model. Moreover, we showed that Compound 44 acts as an autophagy regulator by inducing nuclear translocation of transcription factor EB through GSK-3β inhibition, enhancing the biogenesis of lysosomes and elevating autophagic flux, thus ameliorating the amyloid burden and tauopathy, as well as mitigating the disease phenotype. Our results suggest that triple-target inhibition via Compound 44 could be a promising strategy that may lead to the development of effective therapeutic approaches for AD.
Animals ; Alzheimer Disease/genetics* ; Mice, Transgenic ; Glycogen Synthase Kinase 3 beta/metabolism* ; Disease Models, Animal ; Mice ; Amyloid beta-Peptides/metabolism* ; Cholinesterase Inhibitors/therapeutic use* ; Humans ; Autophagy/drug effects* ; Cognitive Dysfunction/pathology* ; Neuroprotective Agents/pharmacology*

Previous studies have found associations between color discrimination deficits and cognitive impairments besides aging. However, investigations into the microstructural pathology of brain white matter (WM) associated with these deficits remain limited. This study aimed to examine the microstructural characteristics of WM in the non-demented population with abnormal color discrimination, utilizing Neurite Orientation Dispersion and Density Imaging (NODDI), and to explore their correlations with cognitive functions and cognition-related plasma biomarkers. The tract-based spatial statistic analysis revealed significant differences in specific brain regions between the abnormal color discrimination group and the healthy controls, characterized by increased isotropic volume fraction and decreased neurite density index and orientation dispersion index. Further analysis of region-of-interest parameters revealed that the isotropic volume fraction in the bilateral anterior thalamic radiation, superior longitudinal fasciculus, cingulum, and forceps minor was significantly correlated with poorer performance on neuropsychological assessments and to varying degrees various cognition-related plasma biomarkers. These findings provide neuroimaging evidence that WM microstructural abnormalities in non-demented individuals with abnormal color discrimination are associated with cognitive dysfunction, potentially serving as early markers for cognitive decline.
Humans ; White Matter/pathology* ; Male ; Female ; Cognitive Dysfunction/physiopathology* ; Middle Aged ; Aged ; Color Perception/physiology* ; Brain/pathology* ; Neuropsychological Tests ; Diffusion Tensor Imaging

Alzheimer's disease (AD) is the most prevalent neurodegenerative disorder worldwide, causing dementia and affecting millions of individuals. One prominent characteristic in the brains of AD patients is glucose hypometabolism. In the context of galactose metabolism, intracellular glucose levels are heightened. Galactose mutarotase (GALM) plays a crucial role in maintaining normal galactose metabolism by catalyzing the conversion of β-D-galactose into α-D-galactose (α-D-G). The latter is then converted into glucose-6-phosphate, improving glucose metabolism levels. However, the involvement of GALM in AD progression is still unclear. In the present study, we found that the expression of GALM was significantly increased in AD patients and model mice. Genetic knockdown of GALM using adeno-associated virus did not change the expression of amyloid precursor protein (APP) and APP-cleaving enzymes including a disintegrin and metalloprotease 10 (ADAM10), β-site APP-cleaving enzyme 1 (BACE1), and presenilin-1 (PS1). Interestingly, genetic overexpression of GALM reduced APP and Aβ deposition by increasing the maturation of ADAM10, although it did not alter the expression of BACE1 and PS1. Further electrophysiological and behavioral experiments showed that GALM overexpression significantly ameliorated the deficits in hippocampal CA1 long-term potentiation (LTP) and spatial learning and memory in AD model mice. Importantly, direct α-D-G (20 mg/kg, i.p.) also inhibited Aβ deposition by increasing the maturation of ADAM10, thereby improving hippocampal CA1 LTP and spatial learning and memory in AD model mice. Taken together, our results indicate that GALM shifts APP processing towards α-cleavage, preventing Aβ generation by increasing the level of mature ADAM10. These findings indicate that GALM may be a potential therapeutic target for AD, and α-D-G has the potential to be used as a dietary supplement for the prevention and treatment of AD.
Animals ; ADAM10 Protein/metabolism* ; Alzheimer Disease/pathology* ; Amyloid Precursor Protein Secretases/metabolism* ; Disease Models, Animal ; Humans ; Mice ; Amyloid beta-Peptides/metabolism* ; Male ; Mice, Transgenic ; Membrane Proteins/metabolism* ; Cognitive Dysfunction/pathology* ; Mice, Inbred C57BL ; Amyloid beta-Protein Precursor/metabolism* ; Female ; Hippocampus/metabolism* ; Long-Term Potentiation/physiology*

Hemorrhagic shock is a common clinical emergency that can aggravate cell injury after resuscitation. Astrocytes are crucial for the survival of neurons because they regulate the surrounding ionic microenvironment of neurons. Although hemorrhagic shock and resuscitation (HSR) injury can impair cognition, it remains unclear how this insult directly affects astrocytes. In this study, we established an HSR model by bleeding and re-transfusion in mice. The social interaction test and new object recognition test were applied to evaluate post-operative cognitive changes, and the results suggest that mice experience cognitive impairment following exposure to HSR. In the HSR group, the power spectral density of β and γ oscillations decreased, and the coupling of the θ oscillation phase and γ oscillation amplitude was abnormal, which indicated abnormal neuronal oscillation and cognitive impairment after HSR exposure. In brief, cognitive impairment in mice is strongly correlated with Ca²⁺ signal strength in lateral septum astrocytes following HSR.
Animals ; Astrocytes/metabolism* ; Shock, Hemorrhagic/metabolism* ; Resuscitation/adverse effects* ; Male ; Mice ; Calcium Signaling/physiology* ; Mice, Inbred C57BL ; Septal Nuclei/metabolism* ; Cognitive Dysfunction/etiology* ; Disease Models, Animal ; Cognition Disorders/etiology*

Patients suffering from nerve injury often experience exacerbated pain responses and complain of memory deficits. The dorsal hippocampus (dHPC), a well-defined region responsible for learning and memory, displays maladaptive plasticity upon injury, which is assumed to underlie pain hypersensitivity and cognitive deficits. However, much attention has thus far been paid to intracellular mechanisms of plasticity rather than extracellular alterations that might trigger and facilitate intracellular changes. Emerging evidence has shown that nerve injury alters the microarchitecture of the extracellular matrix (ECM) and decreases ECM rigidity in the dHPC. Despite this, it remains elusive which element of the ECM in the dHPC is affected and how it contributes to neuropathic pain and comorbid cognitive deficits. Laminin, a key element of the ECM, consists of α-, β-, and γ-chains and has been implicated in several pathophysiological processes. Here, we showed that peripheral nerve injury downregulates laminin β1 (LAMB1) in the dHPC. Silencing of hippocampal LAMB1 exacerbates pain sensitivity and induces cognitive dysfunction. Further mechanistic analysis revealed that loss of hippocampal LAMB1 causes dysregulated Src/NR2A signaling cascades via interaction with integrin β1, leading to decreased Ca²⁺ levels in pyramidal neurons, which in turn orchestrates structural and functional plasticity and eventually results in exaggerated pain responses and cognitive deficits. In this study, we shed new light on the functional capability of hippocampal ECM LAMB1 in the modulation of neuropathic pain and comorbid cognitive deficits, and reveal a mechanism that conveys extracellular alterations to intracellular plasticity. Moreover, we identified hippocampal LAMB1/integrin β1 signaling as a potential therapeutic target for the treatment of neuropathic pain and related memory loss.
Animals ; Laminin/genetics* ; Hippocampus/metabolism* ; Neuralgia/metabolism* ; Cognitive Dysfunction/etiology* ; Male ; Peripheral Nerve Injuries/metabolism* ; Extracellular Matrix/metabolism* ; Integrin beta1/metabolism* ; Pyramidal Cells/metabolism* ; Signal Transduction

Chronic cerebral hypoperfusion leads to white matter injury (WMI), which plays a significant role in contributing to vascular cognitive impairment. While 13-docosenamide is a type of fatty acid amide, it remains unclear whether it has therapeutic effects on chronic cerebral hypoperfusion. In this study, we conducted bilateral common carotid artery stenosis (BCAS) surgery to simulate chronic cerebral hypoperfusion-induced WMI and cognitive impairment. Our findings showed that 13-docosenamide alleviates WMI and cognitive impairment in BCAS mice. Mechanistically, 13-docosenamide specifically binds to cannabinoid receptor 1 (CNR1) in oligodendrocyte precursor cells (OPCs). This interaction results in an upregulation of ubiquitin-specific peptidase 33 (USP33)-mediated CNR1 deubiquitination, subsequently increasing CNR1 protein expression, activating the phosphorylation of the AKT/mTOR pathway, and promoting the differentiation of OPCs. In conclusion, our study suggests that 13-docosenamide can ameliorate chronic cerebral hypoperfusion-induced WMI and cognitive impairment by enhancing OPC differentiation and could serve as a potential therapeutic drug.
Animals ; Oligodendrocyte Precursor Cells/metabolism* ; Mice ; Cell Differentiation/drug effects* ; Male ; Receptor, Cannabinoid, CB1/metabolism* ; Mice, Inbred C57BL ; Ubiquitin Thiolesterase/metabolism* ; Ubiquitination/drug effects* ; Carotid Stenosis/complications* ; Cognitive Dysfunction/drug therapy*

Neuropathic pain is frequently comorbidity with cognitive deficits. Neuralized1 (Neurl1)-mediated ubiquitination of CPEB3 in the hippocampus is critical in learning and memory. However, the role of Neurl1 in the cognitive impairment in neuropathic pain remains elusive. Herein, we found that lumbar 5 spinal nerve ligation (SNL) in male rat-induced neuropathic pain was followed by learning and memory deficits and LTP impairment in the hippocampus. The Neurl1 expression in the hippocampal CA1 was decreased after SNL. And this decrease paralleled the reduction of ubiquitinated-CPEB3 level and reduced production of GluA1 and GluA2. Overexpression of Neurl1 in the CA1 rescued cognitive deficits and LTP impairment, and reversed the reduction of ubiquitinated-CPEB3 level and the decrease of GluA1 and GluA2 production following SNL. Specific knockdown of Neurl1 or CPEB3 in bilateral hippocampal CA1 in naïve rats resulted in cognitive deficits and impairment of synaptic plasticity. The rescued cognitive function and synaptic plasticity by the treatment of overexpression of Neurl1 before SNL were counteracted by the knockdown of CPEB3 in the CA1. Collectively, the above results suggest that the downregulation of Neurl1 through reducing CPEB3 ubiquitination and, in turn, repressing GluA1 and GluA2 production and mediating synaptic plasticity impairment in hippocampal CA1 leads to the genesis of cognitive deficits in neuropathic pain.
Animals ; Male ; Neuralgia/metabolism* ; Rats ; Down-Regulation/physiology* ; Ubiquitination/physiology* ; Neuronal Plasticity/physiology* ; Rats, Sprague-Dawley ; CA1 Region, Hippocampal/metabolism* ; Cognitive Dysfunction/metabolism* ; RNA-Binding Proteins/metabolism* ; Receptors, AMPA/metabolism*