Cancer-associated fibroblasts (CAFs) are a major cellular component in the tumor microenvironment and have been shown to exhibit protumorigenic effects in hepatocellular carcinoma (HCC). This study ai Show more
Cancer-associated fibroblasts (CAFs) are a major cellular component in the tumor microenvironment and have been shown to exhibit protumorigenic effects in hepatocellular carcinoma (HCC). This study aimed to delve into the mechanisms underlying the tumor-promoting effects of CAFs in HCC. Small RNA sequencing was conducted to screen differential expressed microRNAs in exosomes derived from CAFs and normal fibroblasts (NFs). The miR-92a-3p expression was then measured using reverse transcriptase quantitative real-time PCR in CAFs, NFs, CAFs-derived exosomes (CAFs-Exo), and NF-derived exosomes (NFs-Exo). Compared to NFs or NF-Exo, CAFs and CAFs-Exo significantly promoted HCC cell proliferation, migration, and stemness. Additionally, compared to NFs or NF-Exo, miR-92a-3p level was notably higher in CAFs and CAFs-Exo, respectively. Exosomal miR-92a-3p was found to enhance HCC cell proliferation, migration, and stemness. Meanwhile, AXIN1 was targeted by miR-92a-3p. Exosomal miR-92a-3p could activate β-catenin/CD44 signaling in HCC cells by inhibiting AXIN1 messenger RNA. Furthermore, in vivo studies verified that exosomal miR-92a-3p notably promoted tumor growth and stemness through targeting AXIN1/β-catenin axis. Collectively, CAFs secreted exosomal miR-92a-3p was capable of promoting growth and stemness in HCC through activation of Wnt/β-catenin signaling pathway by suppressing AXIN1. Therefore, targeting CAFs-derived miR-92a-3p may be a potential strategy for treating HCC. Show less
The current understanding to the mechanism of rumen development is limited. We hypothesized that the Hippo signaling pathway controlled the proliferation of rumen epithelium (RE) during postnatal deve Show more
The current understanding to the mechanism of rumen development is limited. We hypothesized that the Hippo signaling pathway controlled the proliferation of rumen epithelium (RE) during postnatal development. In the present study, we firstly tested the changes of the Hippo signaling pathway in the RE during an early growing period from d5 to d25, and then we expanded the time range to the whole preweaning period (d10-38) and one week post weaning (d45). An in vitro experiment was also carried out to verify the function of Hippo signaling pathway during RE cell proliferation. In the RE of lambs from d5 to d25, the expression of baculoviral IAP repeat containing (BIRC3/5) was increased, while the expressions of large tumor suppressor kinase 2 (LATS2), TEA domain transcription factor 3 (TEAD3), axin 1 (AXIN1), and MYC proto-oncogene (MYC) were decreased with rumen growth. From d10 to d38, the RE expressions of BIRC3/5 were increased, while the expressions of LATS2 and MYC were decreased, which were similar with the changes in RE from d5 to d25. From d38 to d45, different changes were observed, with the expressions of LATS1/2, MOB kinase activator 1B (MOB1B), and TEAD1 increased, while the expressions of MST1 and BIRC5 decreased. Correlation analysis showed that during the preweaning period, the RE expressions of BIRC3/5 were positively correlated with rumen development variables, while LAST2 was negatively correlated with rumen development variables. The in vitro experiment validated the changes of LATS2 and BIRC3/5 in the proliferating RE cells, which supported their roles in RE proliferation during preweaning period. Our results suggest that the LATS2-YAP1-BIRC3/5 axis participates in the RE cell proliferation and promotes rumen growth during the preweaning period. Show less
Casein kinase 1ε (CK1ε) and axis inhibitor 1 (AXIN1) are crucial components of the β-catenin destruction complex in canonical Wnt signaling. CK1ε has been shown to interact with AXIN1, but its physiol Show more
Casein kinase 1ε (CK1ε) and axis inhibitor 1 (AXIN1) are crucial components of the β-catenin destruction complex in canonical Wnt signaling. CK1ε has been shown to interact with AXIN1, but its physiological function and role in tumorigenesis remain unknown. In this study, we found that CK1δ/ε inhibitors significantly enhanced AXIN1 protein level in colorectal cancer (CRC) cells through targeting CK1ε. Mechanistically, CK1ε promoted AXIN1 degradation by the ubiquitin-proteasome pathway by promoting the interaction of E3 ubiquitin-protein ligase SIAH1 with AXIN1. Genetic or pharmacological inhibition of CK1ε and knockdown of SIAH1 downregulated the expression of Wnt/β-catenin-dependent genes, suppressed the viability of CRC cells, and restrained tumorigenesis and progression of CRC in vitro and in vivo. In summary, our results demonstrate that CK1ε exerted its oncogenic role in CRC occurrence and progression by regulating the stability of AXIN1. These findings reveal a novel mechanism by which CK1ε regulates the Wnt/β-catenin signaling pathway and highlight the therapeutic potential of targeting the CK1ε/SIAH1 axis in CRC. Show less
AXIN1 is a major component of the β-catenin destruction complex and is frequently mutated in various cancer types, particularly liver cancers. Truncating AXIN1 mutations are recognized to encode a def Show more
AXIN1 is a major component of the β-catenin destruction complex and is frequently mutated in various cancer types, particularly liver cancers. Truncating AXIN1 mutations are recognized to encode a defective protein that leads to β-catenin stabilization, but the functional consequences of missense mutations are not well characterized. Here, we first identified the GSK3β, β-catenin, and RGS/APC interaction domains of AXIN1 that are the most critical for proper β-catenin regulation. Analysis of 80 tumor-associated variants in these domains identified 18 that significantly affected β-catenin signaling. Coimmunoprecipitation experiments revealed that most of them lost binding to the binding partner corresponding to the mutated domain. A comprehensive protein structure analysis predicted the consequences of these mutations, which largely overlapped with the observed effects on β-catenin signaling in functional experiments. The structure analysis also predicted that loss-of-function mutations within the RGS/APC interaction domain either directly affected the interface for APC binding or were located within the hydrophobic core and destabilized the entire structure. In addition, truncated AXIN1 length inversely correlated with the β-catenin regulatory function, with longer proteins retaining more functionality. These analyses suggest that all AXIN1-truncating mutations at least partially affect β-catenin regulation, whereas this is only the case for a subset of missense mutations. Consistently, most colorectal and liver cancers carrying missense variants acquire mutations in other β-catenin regulatory genes such as APC and CTNNB1. These results will aid the functional annotation of AXIN1 mutations identified in large-scale sequencing efforts or in individual patients. Characterization of 80 tumor-associated missense variants of AXIN1 reveals a subset of 18 mutations that disrupt its β-catenin regulatory function, whereas the majority are passenger mutations. Show less
Osimertinib, a promising and approved third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI), is a standard strategy for EGFR-mutant non-small cell lung cancer (NSCLC Show more
Osimertinib, a promising and approved third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI), is a standard strategy for EGFR-mutant non-small cell lung cancer (NSCLC) patients. However, developed resistance is unavoidable, which reduces its long-term effectiveness. In this study, RNA sequencing was performed to analyze differentially expressed genes (DEGs). The PrognoScan database and Gene Expression Profiling Interactive Analysis (GEPIA) were used to identify the key genes for clinical prognosis and gene correlation respectively. Protein expression was determined by western blot analysis. Cell viability assay and Ki67 staining were used to evaluate the effect of osimertinib on tumor cells. Finally, we screened out two hub genes, myelocytomatosis oncogene (Myc) and axis inhibition protein 1 (Axin1), upregulated in three osimertinib-resistant cell lines through RNA sequencing and bioinformatics analysis. Next, cell experiment confirmed that expression of C-MYC and AXIN1 were elevated in different EGFR mutant NSCLC cell lines with acquired resistance to osimertinib, compared with their corresponding parental cell lines. Furthermore, we demonstrated that AXIN1 upregulated the expression of C-MYC and mediated the acquired resistance of EGFR mutant NSCLC cells to osimertinib in vitro. In conclusion, AXIN1 affected the sensitivity of EGFR mutant NSCLC to osimertinib via regulating C-MYC expression in vitro. Targeting AXIN1/MYC signaling may be a potential new strategy for overcoming acquired resistance to osimertinib. Show less
R-spondins (RSPOs) are secreted signaling molecules that potentiate the Wnt/β-catenin pathway by cooperating with Wnt ligands. RSPO1 is crucial in tissue development and tissue homeostasis. However, t Show more
R-spondins (RSPOs) are secreted signaling molecules that potentiate the Wnt/β-catenin pathway by cooperating with Wnt ligands. RSPO1 is crucial in tissue development and tissue homeostasis. However, the molecular mechanism by which RSPOs activate Wnt/β-catenin signaling remains elusive. In this study, we found that RSPOs could mediate the degradation of Axin through the ubiquitin-proteasome pathway. The results of Co-IP showed that the recombinant RSPO1 protein promoted the interaction between Axin1 and CK1ε. Either knockout of the CK1ε gene or treatment with the CK1δ/CK1ε inhibitor SR3029 caused an increase in Axin1 protein levels and attenuated RSPO1-induced degradation of the Axin1 protein. Moreover, we observed an increase in the number of associations of LRP6 with CK1ε and Axin1 following RSPO1 stimulation. Overexpression of LRP6 further potentiated Axin1 degradation mediated by RSPO1 or CK1ε. In addition, recombinant RSPO1 and Wnt3A proteins synergistically downregulated the protein expression of Axin1 and enhanced the transcriptional activity of the SuperTOPFlash reporter. Taken together, these results uncover the novel mechanism by which RSPOs activate Wnt/β-catenin signaling through LRP6/CK1ε-mediated degradation of Axin. Show less
We enrolled 163 participants with CSVD (114 cerebral amyloid angiopathy and 49 hypertensive hemorrhage), and 96 cognitively unimpaired elders and 40 participants with Alzheimer's disease as controls. Show more
We enrolled 163 participants with CSVD (114 cerebral amyloid angiopathy and 49 hypertensive hemorrhage), and 96 cognitively unimpaired elders and 40 participants with Alzheimer's disease as controls. We measured BACE1 activity using a synthetic fluorescence substrate enzyme-linked immunosorbent assay. We used regression models to investigate associations between BACE1 and imaging and blood markers as well as clinical outcomes in CSVD. Plasma BACE1 activity was significantly higher in CSVD (median 862.0 relative fluorescence units [RFU], interquartile range 700.6-1032.9) compared with elder controls (522.5 RFU, 438.3-662.1, Plasma BACE1 activity is moderately increased and associated with neurodegeneration and cognitive impairment risk in CSVD. It indicates that BACE1 is a promising biomarker especially for CSVD-related neurodegeneration. Show less
Type 2 diabetes mellitus (T2DM) is a metabolic disorder that is characterized by insulin resistance and hyperglycemia. It is also known to be a risk factor for Alzheimer's disease (AD). Insulin plays Show more
Type 2 diabetes mellitus (T2DM) is a metabolic disorder that is characterized by insulin resistance and hyperglycemia. It is also known to be a risk factor for Alzheimer's disease (AD). Insulin plays a crucial role in regulating the body's metabolism and is responsible for activating the Phosphoinotide-3-Kinase (PI3K)/Protein Kinase B (Akt) signaling pathway. This pathway is activated when insulin binds to the insulin receptor on nerve cells, and it helps regulate the metabolism of glucose and lipids. Dysfunction in the insulin signaling pathway can lead to a decrease in brain insulin levels and insulin sensitivity, thereby inducing disruptions in insulin signal transduction and leading to disorders in brain energy metabolism. Moreover, these dysfunctions also contribute to the accumulation of β-amyloid (Aβ) deposition and the hyperphosphorylation of Tau protein, both of which are characteristic features of AD. Therefore, this article focuses on insulin resistance to reveal the complex mechanism between brain insulin resistance and AD occurrence in T2DM. On this basis, this article further summarizes the biological effects and mechanisms of antidiabetic drugs on the two diseases, aiming to provide new ideas for the discovery of drugs for the treatment of T2DM combined with AD. Show less
Clinical studies have shown that epileptic seizures worsen Alzheimer's disease (AD) pathology and related cognitive deficits; however, the underlying mechanism is unclear. To assess the effects of sei Show more
Clinical studies have shown that epileptic seizures worsen Alzheimer's disease (AD) pathology and related cognitive deficits; however, the underlying mechanism is unclear. To assess the effects of seizures on the progression of AD, chronic temporal lobe epilepsy was induced in five familial AD mutation (5×FAD) mice by kindling with the chemoconvulsant pentylenetetrazole (PTZ) at 3-3.5 months of age. The amyloidogenic pathway, tauopathy, synaptic damage, neuronal death, neurological inflammatory response and associated kinase signaling pathway dysregulation were examined at 9 months of age. We found that APP, p-APP, BACE1, Aβ and kinase-associated p-tau levels were elevated after PTZ kindling in 5×FAD mice. In addition, PTZ kindling exacerbated hippocampal synaptic damage and neuronal cell death, as determined by scanning electron microscopy and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) staining, respectively. Finally, the levels of the neuroinflammation markers GFAP and Iba1, as well as the inflammatory cytokine IL-1β, were increased after PTZ insult. PTZ kindling profoundly exacerbated extracellular regulated kinase (ERK)-death-associated protein kinase (DAPK) signaling pathway overactivation, and acute ERK inhibitor treatment downregulated Aβ production and p-APP and p-tau levels in epileptic 5×FAD mice. In addition, long-term use of the antiseizure drug carbamazepine (CBZ) alleviated seizure-induced accelerated amyloid and tau pathology and ERK-DAPK overactivation in 5×FAD mice. Collectively, these results demonstrate that seizure-induced increases in AD-like neuropathology in 5×FAD mice are partially regulated by the ERK-DAPK pathway, suggesting that the ERK-DAPK axis could be a new therapeutic target for the treatment of AD patients with comorbid seizures. Show less
The profile of autoantibodies is dysregulated in patients with Alzheimer's disease (AD). Autoantibodies to beta-site amyloid precursor protein (APP)-cleaving enzyme 1 (BACE1) are present in human bloo Show more
The profile of autoantibodies is dysregulated in patients with Alzheimer's disease (AD). Autoantibodies to beta-site amyloid precursor protein (APP)-cleaving enzyme 1 (BACE1) are present in human blood. This study aims to investigate the clinical relevance and pathophysiological roles of autoantibodies to BACE1 in AD. Clinical investigations were conducted in two independent cohorts, the Chongqing cohort, and the Australian Imaging, Biomarkers, and Lifestyle (AIBL) cohort. The Chongqing cohort included 55 AD patients, 28 patients with non-AD dementia, and 70 cognitively normal subjects (CN). The AIBL cohort included 162 Aβ-PET Show less
Hepatocellular carcinoma (HCC) is among the most prevalent digestive system malignancies and is associated with a poor prognosis. Necroptosis, a form of regulated death mediated by death receptors, ex Show more
Hepatocellular carcinoma (HCC) is among the most prevalent digestive system malignancies and is associated with a poor prognosis. Necroptosis, a form of regulated death mediated by death receptors, exhibits characteristics of both necrosis and apoptosis. Long non-coding RNAs (lncRNAs) have been identified as crucial regulators in tumor necroptosis. This study aims to identify the necroptosis-related lncRNAs (np-lncRNA) in HCC and investigate their relationships with prognosis. The RNA-sequencing data, along with clinicopathological and survival information of HCC patients were sourced from The Cancer Genome Atlas (TCGA) database. The np-lncRNAs were analyzed to assess their potential in predicting HCC prognosis. Prognostic signatures related to necroptosis were constructed using stepwise multivariate Cox regression analysis. The prognosis of patients was compared using Kaplan-Meier (KM) analysis. The accuracy of the prognostic signature was evaluated using Receiver operating characteristic (ROC) analysis and decision curve analysis (DCA). Quantitative real-time polymerase chain reaction(qPCR) was employed to validate the lncRNAs expression levels of lncRNAs among samples from an independent cohort. The np-lncRNAs ZFPM2-AS1, AC099850.3, BACE1-AS, KDM4A-AS1 and MKLN1-AS were identified as potential prognostic biomarkers. The prognostic signature constructed from these np-lncRNAs achieved an Area Under the Curve (AUC) of 0.773. Based on the risk score derived from the signature, patients were divided into two groups, with the high-risk group exhibiting poorer overall survival. Gene Set Enrichment Analysis (GSEA) revealed significantly different between the low risk and high risk groups in tumor-related pathways (such as mTOR, MAPK and p53 signaling pathways) and immune-related functions (like T cell receptor signaling pathway and natural killer cell mediated cytotoxicity). The increased expression of np-lncRNAs was confirmed in another independent HCC cohort. This signature offers a dependable method for forecasting the prognosis of HCC patients. Our findings indicate a subset of np-lncRNA biomarkers that could be utilized for prognosis prediction and personalized treatment strategies of HCC patients. Show less
The production of neurotoxic amyloid-β peptides (Aβ) is central to the initiation and progression of Alzheimer's disease (AD) and involves sequential cleavage of the amyloid precursor protein (APP) by Show more
The production of neurotoxic amyloid-β peptides (Aβ) is central to the initiation and progression of Alzheimer's disease (AD) and involves sequential cleavage of the amyloid precursor protein (APP) by β- and γ-secretases. APP and the secretases are transmembrane proteins and their co-localisation in the same membrane-bound sub-compartment is necessary for APP cleavage. The intracellular trafficking of APP and the β-secretase, BACE1, is critical in regulating APP processing and Aβ production and has been studied in several cellular systems. Here, we summarise the intracellular distribution and transport of APP and its secretases, and the intracellular location for APP cleavage in non-polarised cells and neuronal models. In addition, we review recent advances on the potential impact of familial AD mutations on APP trafficking and processing. This is critical information in understanding the molecular mechanisms of AD progression and in supporting the development of novel strategies for clinical treatment. Show less
CSF biomarkers have immense diagnostic and prognostic potential for Alzheimer disease (AD). However, AD is still diagnosed relatively late in the disease process, sometimes even years after the initia Show more
CSF biomarkers have immense diagnostic and prognostic potential for Alzheimer disease (AD). However, AD is still diagnosed relatively late in the disease process, sometimes even years after the initial manifestation of cognitive symptoms. Thus, further identification of biomarkers is required to detect related pathology in the preclinical stage and predict cognitive decline. Our study aimed to assess the association of neurogranin and β-site amyloid precursor protein-cleaving enzyme 1 (BACE1) with cognitive decline in individuals with subjective cognitive decline (SCD). We enrolled participants with available neurogranin and BACE1 measurements in CSF from the DELCODE (DZNE-Longitudinal Cognitive Impairment and Dementia, Germany) cohort. The longitudinal change of Preclinical Alzheimer's Cognitive Composite score was assessed as the primary outcome in participants with SCD and controls. The secondary outcome was defined as conversion of SCD to mild cognitive impairment (MCI) during follow-up. Levels of neurogranin, BACE1, and neurogranin/BACE1 ratio across groups were compared by analysis of covariance after adjustment for demographics. The linear mixed-effects model and Cox regression analysis were applied to evaluate their association with cognitive decline and progression of SCD to MCI, respectively. A total of 530 participants (mean age: 70.76 ± 6.01 years, 48.7% female) were analyzed in the study. The rate of cognitive decline was faster in individuals with SCD with higher neurogranin and neurogranin/BACE1 ratio (β = -0.138, SE = 0.065, Our findings suggest that CSF neurogranin and BACE1 begin to change in the preclinical stage of AD and they are associated with clinical progression in individuals with SCD. Show less
Social isolation (SI) is a common phenomenon in the modern world, especially during the coronavirus disease 2019 pandemic, and causes lasting cognitive impairments and mental disorders. However, it is Show more
Social isolation (SI) is a common phenomenon in the modern world, especially during the coronavirus disease 2019 pandemic, and causes lasting cognitive impairments and mental disorders. However, it is still unclear how SI alters molecules in the brain and induces behavioural dysfunctions. Here, we report that SI impairs cognitive function and induces depressive-like behaviours in C57BL/6 J mice, in addition to impairing synaptic plasticity and increasing the levels of APP cleavage-related enzymes, thereby promoting Aβ production. Moreover, we show that in APP/PS1 transgenic mice, SI accelerates pathological changes and behavioural deficits. Interestingly, downregulation of the expression of the BACE1 attenuates SI-induced Aβ toxicity and synaptic dysfunction. Furthermore, early intervention with BACE1 shRNA blocks SI-induced cognitive impairments. Together, our data strongly suggest that SI-induced upregulation of BACE1 expression mediates Aβ toxicity and induces behavioural deficits. Down-regulation of BACE1 may be a promising strategy for preventing SI-induced cognitive impairments. Show less
Alzheimer's disease (AD) is the most common form of dementia among the elderly, accounting for 60 %-70 % of cases. At present, the pathogenesis of this condition remains unclear, but the hydrolysis of Show more
Alzheimer's disease (AD) is the most common form of dementia among the elderly, accounting for 60 %-70 % of cases. At present, the pathogenesis of this condition remains unclear, but the hydrolysis of acetylcholine (ACh) is thought to play a role. Acetylcholinesterase (AChE) can break down ACh transmission from the presynaptic membrane and stop neurotransmitters' excitatory effect on the postsynaptic membrane, which plays a key role in nerve conduction. Acetylcholinesterase inhibitors (AChEIs) can delay the hydrolysis of acetylcholine (ACh), which represents a key strategy for treating AD. Due to its complex etiology, AD has proven challenging to treat. Various inhibitors and antagonists targeting key enzymes and proteins implicated in the disease's pathogenesis have been explored as potential therapeutic agents. These include Glycogen Synthase Kinase 3β (GSK-3β) inhibitors, β-site APP Cleaving Enzyme (BACE-1) inhibitors, Monoamine Oxidase (MAO) inhibitors, Phosphodiesterase inhibitors (PDEs), N-methyl--aspartic Acid (NMDA) antagonists, Histamine 3 receptor antagonists (H3R), Serotonin receptor subtype 4 (5-HT4R) antagonists, Sigma1 receptor antagonists (S1R) and soluble Epoxide Hydrolase (sEH) inhibitors. The drug development strategy of multi-target-directed ligands (MTDLs) offers unique advantages in the treatment of complex diseases. On the one hand, it can synergistically enhance the therapeutic efficacy of single-target drugs. On the other hand, it can also reduce the side effects. In this review, we discuss the design strategy of dual inhibitors based on acetylcholinesterase and the structure-activity relationship of these drugs. Show less
An in-situ nanozyme signal tag combined with a DNA-mediated universal antibody-oriented strategy was proposed to establish a high-performance immunosensing platform for Alzheimer's disease (AD)-relate Show more
An in-situ nanozyme signal tag combined with a DNA-mediated universal antibody-oriented strategy was proposed to establish a high-performance immunosensing platform for Alzheimer's disease (AD)-related biomarker detection. Briefly, a Zr-based metal-organic framework (MOF) with peroxidase (POD)-like activity was synthesized to encapsulating the electroactive molecule methylene blue (MB), and subsequently modified with a layer of gold nanoparticles on its surface. This led to the creation of double POD-like activity nanozymes surrounding the MB molecule to form a nanozyme signal tag. A large number of hydroxyl radicals were generated by the nanozyme signal tag with the help of H Show less
Alzheimer's disease (AD) is a neurodegenerative disorder associated with age. A wealth of evidence indicates that the amyloid β (Aβ) aggregates result from dyshomeostasis between Aβ production and cle Show more
Alzheimer's disease (AD) is a neurodegenerative disorder associated with age. A wealth of evidence indicates that the amyloid β (Aβ) aggregates result from dyshomeostasis between Aβ production and clearance, which plays a pivotal role in the pathogenesis of AD. Consequently, therapies targeting Aβ reduction represent a promising strategy for AD intervention. Tetramethylpyrazine nitrone (TBN) is a novel tetramethylpyrazine derivative with potential for the treatment of AD. Previously, we demonstrated that TBN markedly enhanced cognitive functions and decreased the levels of Aβ, APP, BACE 1, and hyperphosphorylated tau in 3×Tg-AD mice. However, the mechanism by which TBN inhibits Aβ deposition is still unclear. In this study, we employed APP/PS1 mice treated with TBN (60 mg/kg, ig, bid) for six months, and N2a/APP695swe cells treated with TBN (300 μM) to explore the mechanism of TBN in Aβ reduction. Our results indicate that TBN significantly alleviated cognitive impairment and reduced Aβ deposition in APP/PS1 mice. Further investigation of the underlying mechanisms revealed that TBN decreased the expression of APP and BACE1, activated the AMPK/mTOR/ULK1 autophagy pathway, inhibited the PI3K/AKT/mTOR/ULK1 autophagy pathway, and decreased the phosphorylation levels of JNK and ERK in APP/PS1 mice. Moreover, TBN was found to significantly reduce the mRNA levels of APP and BACE1, as well as those of SP1, CTCF, TGF-β, and NF-κB, transcription factors involved in regulating gene expression. Additionally, TBN was observed to decrease the level of Show less
The fruits of Alpinia oxyphylla (Alpiniae Oxyphyllae Fructus, AOF) are one of the "Four Famous South Medicines" in China. In this study, beta-site amyloid protein precursor cleaving enzyme 1 (BACE1) w Show more
The fruits of Alpinia oxyphylla (Alpiniae Oxyphyllae Fructus, AOF) are one of the "Four Famous South Medicines" in China. In this study, beta-site amyloid protein precursor cleaving enzyme 1 (BACE1) was applied to explore the active components in AOF responsible for type 2 diabetes mellitus (T2DM)-related cognitive disorder. As a result, 24 compounds including three unreported ones (1, 3, 4) were isolated from AOF. Compound 1 is an unusual carbon‑carbon linked diarylheptanoid dimer, and compound 4 is the first case of 3,4-seco-eudesmane sesquiterpenoid with a 5/6-bicyclic skeleton. Four diarylheptanoids (3, 5-7), one flavonoid (9) and two sesquiterpenoids (14 and 20) showed BACE1 inhibitory activity, of which the most active 6 was revealed to be a non-competitive and anti-competitive mixed inhibitor. Docking simulation suggested that OH-4' of 6 played important roles in maintaining activity by forming hydrogen bonds with Ser36 and Ile126 residues. Compounds 3, 5, 9 and 20 displayed neuroprotective effects against amyloid β (Aβ)-induced damage in BV2 cells. Mechanism study revealed that compounds 5 and 20 downregulated the expression of BACE1 and upregulated the expression of Lamp2 to exert effects. Thus, the characteristic diarylheptanoids and sesquiterpenoids in AOF had the efficacy to alleviate T2DM-related cognitive disorder by inhibiting BACE1 activity and reversing Aβ-induced neuronal damage. Show less
Alzheimer's disease (AD) is the most common fatal neurodegenerative disease among the elderly worldwide, characterized by memory and cognitive impairment. The identification of biomarkers for AD is cr Show more
Alzheimer's disease (AD) is the most common fatal neurodegenerative disease among the elderly worldwide, characterized by memory and cognitive impairment. The identification of biomarkers for AD is crucial and urgent to facilitate the diagnosis and intervention. The aim of this study was to evaluate the diagnostic value of acyl-Coenzyme A thioesterase 7 (ACOT7) as a serum biomarker for the prediction of AD. In our study, we observed a significant increase in ACOT7 expression in patients ( Show less
Dual specificity protein phosphatase 6 (DUSP6) was recently identified as a key hub gene in a causal To investigate the role of DUSP6 in AD, we stereotactically injected AAV5-DUSP6 or AAV5-GFP (contro Show more
Dual specificity protein phosphatase 6 (DUSP6) was recently identified as a key hub gene in a causal To investigate the role of DUSP6 in AD, we stereotactically injected AAV5-DUSP6 or AAV5-GFP (control) into the dorsal hippocampus (dHc) of both female and male 5xFAD or wild type mice, to induce overexpression of DUSP6 or GFP. Barnes maze testing indicated that DUSP6 overexpression in the dHc of 5xFAD mice improved memory deficits and was associated with reduced amyloid plaque load, Aß In summary, DUSP6 overexpression in dHc reduced amyloid deposition and memory deficits in male but not female 5xFAD mice, whereas reduced neuroinflammation and microglial activation were observed in both males and females, suggesting that DUSP6-induced reduction of microglial activation did not contribute to sex-dependent improvement in memory deficits. The sex-dependent regulation of synaptic pathways by DUSP6 overexpression, however, correlated with the improvement of spatial memory deficits in male but not female 5xFAD. Show less
SIL1, an endoplasmic reticulum (ER)-resident protein, is reported to play a protective role in Alzheimer's disease (AD). However, the effect of SIL1 on amyloid precursor protein (APP) processing remai Show more
SIL1, an endoplasmic reticulum (ER)-resident protein, is reported to play a protective role in Alzheimer's disease (AD). However, the effect of SIL1 on amyloid precursor protein (APP) processing remains unclear. In this study, the role of SIL1 in APP processing was explored both Show less
Amyloid plaques, a major pathological hallmark of Alzheimer's disease (AD), are caused by an imbalance between the amyloidogenic and non-amyloidogenic pathways of amyloid precursor protein (APP). BACE Show more
Amyloid plaques, a major pathological hallmark of Alzheimer's disease (AD), are caused by an imbalance between the amyloidogenic and non-amyloidogenic pathways of amyloid precursor protein (APP). BACE1 cleavage of APP is the rate-limiting step for amyloid-β production and plaque formation in AD. Although the alteration of BACE1 expression in AD has been investigated, the underlying mechanisms remain unknown. In this study, we determined MEIS2 was notably elevated in AD models and AD patients. Alterations in the expression of MEIS2 can modulate the levels of BACE1. MEIS2 downregulation improved the learning and memory retention of AD mice and decreased the number of amyloid plaques. MEIS2 binds to the BACE1 promoter, positively regulates BACE1 expression, and accelerates APP amyloid degradation in vitro. Therefore, our findings suggest that MEIS2 might be a critical transcription factor in AD, since it regulates BACE1 expression and accelerates BACE1-mediated APP amyloidogenic cleavage. MEIS2 is a promising early intervention target for AD treatment. Show less
Olfactory dysfunction is increasingly recognized as an early indicator of Alzheimer's disease (AD). Aberrations in GABAergic function and the excitatory/inhibitory (E/I) balance within the olfactory b Show more
Olfactory dysfunction is increasingly recognized as an early indicator of Alzheimer's disease (AD). Aberrations in GABAergic function and the excitatory/inhibitory (E/I) balance within the olfactory bulb (OB) have been implicated in olfactory impairment during the initial stages of AD. While the neuregulin 1 (NRG1)/ErbB4 signaling pathway is known to regulate GABAergic transmission in the brain and is associated with various neuropsychiatric disorders, its specific role in early AD-related olfactory impairment remains incompletely understood. This study demonstrated that olfactory dysfunction preceded cognitive decline in young adult APP/PS1 mice and was characterized by reduced levels of NRG1 and ErbB4 in the OB. Further investigation revealed that deletion of ErbB4 in parvalbumin interneurons reduced GABAergic transmission and increased hyperexcitability in mitral and tufted cells (M/Ts) in the OB, thereby accelerating olfactory dysfunction in young adult APP/PS1 mice. Additionally, ErbB4 deficiency was associated with increased accumulation of Aβ and BACE1-mediated cleavage of APP, along with enhanced CDK5 signaling in the OB. NRG1 infusion into the OB was found to enhance GABAergic transmission in M/Ts and alleviate olfactory dysfunction in young adult APP/PS1 mice. These findings underscore the critical role of NRG1/ErbB4 signaling in regulating GABAergic transmission and E/I balance within the OB, contributing to olfactory impairment in young adult APP/PS1 mice, and provide novel insights for early intervention strategies in AD. This work has shown that ErbB4 deficiency increased the burden of Aβ, impaired GABAergic transmission, and disrupted the E/I balance of mitral and tufted cells (M/Ts) in the OB, ultimately resulting in olfactory dysfunction in young adult APP/PS1 mice. NRG1 could enhance GABAergic transmission, rescue E/I imbalance in M/Ts, and alleviate olfactory dysfunction in young adult APP/PS1 mice. OB: olfactory bulb, E/I: excitation/inhibition, Pr: probability of release, PV: parvalbumin interneurons, Aβ: β-amyloid, GABA: gamma-aminobutyric acid. Show less
Microsomal glutathione transferase 3 (MGST3) regulates eicosanoid and glutathione metabolism. These processes are associated with oxidative stress and apoptosis, suggesting that MGST3 might play a rol Show more
Microsomal glutathione transferase 3 (MGST3) regulates eicosanoid and glutathione metabolism. These processes are associated with oxidative stress and apoptosis, suggesting that MGST3 might play a role in the pathophysiology of Alzheimer's disease. Here, we report that knockdown (KD) of MGST3 in cell lines reduced the protein level of beta-site amyloid precursor protein cleaving enzyme 1 (BACE1) and the resulting amyloidogenesis. Interestingly, MGST3 KD did not alter intracellular reactive oxygen species level but selectively reduced the expression of apoptosis indicators which could be associated with the receptor of cysteinyl leukotrienes, the downstream metabolites of MGST3 in arachidonic acid pathway. We then showed that the effect of MGST3 on BACE1 was independent of cysteinyl leukotrienes but involved a translational mechanism. Further RNA-seq analysis identified that regulator of G-protein signaling 4 (RGS4) was a target gene of MGST3. Silencing of RGS4 inhibited BACE1 translation and prevented MGST3 KD-mediated reduction of BACE1. The potential mechanism was related to AKT activity, as the protein level of phosphorylated AKT was significantly reduced by silencing of MGST3 and RGS4, and the AKT inhibitor abolished the effect of MGST3/RGS4 on phosphorylated AKT and BACE1. Together, MGST3 regulated amyloidogenesis by controlling BACE1 protein expression, which was mediated by RGS4 and downstream AKT signaling pathway. Show less
BACE1, a crucial enzyme in the amyloid-β deposition theory of Alzheimer's disease (AD), is targeted by Codonopsis pilosula, a traditional tonic believed to impede AD onset. However, the specific activ Show more
BACE1, a crucial enzyme in the amyloid-β deposition theory of Alzheimer's disease (AD), is targeted by Codonopsis pilosula, a traditional tonic believed to impede AD onset. However, the specific active compounds responsible for its effects remain elusive. Our prior network pharmacology research identified C. pilosula polysaccharides (CPPS) and Lobetyolin may serve as potential inhibitors of AD by suppressing amyloidogenesis. Here, we recombinantly expressed BACE1 under varied conditions and assessed its activity using Fluorescence Resonance Energy Transfer technology. Through spectroscopy, molecular docking, and dynamics, we elucidated the interactions of CPPS, Lobetyolin, and BACE1. Optimal BACE1 expression occurred at 22 °C with 0.4 mM IPTG for 6 h, yielding a 72 kDa protein. Enzyme kinetics displayed a maximum rate of 4096 μmol/min and a Michaelis constant of 16 mg/mL for BACE1. Spectroscopic analysis revealed differing binding affinities of the compounds at various temperatures, peaking at 293 K. Lobetyolin exhibited superior binding to BACE1 compared to CPPS, driven by hydrophobic and electrostatic forces. Molecular docking and dynamics highlighted hydrophobic amino acids' role in BACE1 interactions with Lobetyolin and CPPS, with binding energy < -1.2 kcal/mol signifying strong affinities. Notably, Lobetyolin and CPPS showed higher BACE1 affinity than APP, with the Lobetyolin-BACE1 complex being the most stable. Show less
Long-term exposure to lead (Pb) can result in chronic damage to the body through accumulation in the central nervous system (CNS) leading to neurodegenerative diseases, such as Alzheimer's disease (AD Show more
Long-term exposure to lead (Pb) can result in chronic damage to the body through accumulation in the central nervous system (CNS) leading to neurodegenerative diseases, such as Alzheimer's disease (AD). This study delves into the intricate role of miR-671/CDR1as regulation in the etiology of AD-like lesions triggered by chronic Pb exposure in adult mice. To emulate the chronic effects of Pb, we established a rodent model spanning 10 months of controlled Pb administration, dividing 52 C57BL/6J mice into groups receiving varying concentrations of Pb (1, 2, or 4 g/L) alongside an unexposed control. Blood Pb levels were monitored using serum samples to ensure accurate dosing and to correlate with observed toxicological outcomes. Utilizing the Morris water maze, a robust behavioral assay for assessing cognitive functions, we documented a dose-dependent decline in learning and memory capabilities among the Pb-exposed mice. Histopathological examination of the hippocampal tissue revealed tell-tale signs of AD-like neurodegeneration, characterized by the accumulation of amyloid plaques and neurofibrillary tangles. At the molecular level, a significant upregulation of AD-associated genes, namely amyloid precursor protein (APP), β-secretase 1 (BACE1), and tau, was observed in the hippocampal tissue of Pb-exposed mice. This was accompanied by a corresponding surge in the protein levels of APP, BACE1, amyloid-β (Aβ), and phosphorylated tau (p-tau), further implicating Pb in the dysregulation of these key AD markers. The expression of CDR1as, a long non-coding RNA implicated in AD pathogenesis, was found to be suppressed in Pb-exposed mice. This observation suggests a potential mechanistic link between Pb-induced neurotoxicity and the dysregulation of the CDR1as/miR-671 axis, which warrants further investigation. Moreover, our study identified a dose-dependent alteration in the intracellular and extracellular levels of the transcription factor nuclear factor-kappa B (NF-κB). This finding implicates Pb in the modulation of NF-κB signaling, a pathway that plays a pivotal role in neuroinflammation and neurodegeneration. In conclusion, our findings underscored the deleterious effects of Pb exposure on the CNS, leading to the development of AD-like pathology. The observed modulation of NF-κB signaling and miR-671/CDR1as regulation provides a plausible mechanistic framework for understanding the neurotoxic effects of Pb and its potential contribution to AD pathogenesis. Show less
Β-site amyloid precursor protein (APP) cleaving enzyme (BACE1) is a crucial protease in the production of amyloid-β (Aβ) in Alzheimer's disease (AD) patients. However, the side effects observed in cli Show more
Β-site amyloid precursor protein (APP) cleaving enzyme (BACE1) is a crucial protease in the production of amyloid-β (Aβ) in Alzheimer's disease (AD) patients. However, the side effects observed in clinical trials of BACE1 inhibitors, including reduction in brain volume and cognitive worsening, suggest that the exact role of BACE1 in AD pathology is not fully understood. To further investigate this, we examined cerebrospinal fluid (CSF) levels of BACE1 and its cleaved product sAPPβ that reflects BACE1 activity in the China Aging and Neurodegenerative Disorder Initiative cohort. We found significant correlations between CSF BACE1 or sAPPβ levels and CSF Aβ40, Aβ42, and Aβ42/Aβ40 ratio, but not with amyloid deposition detected by 18F-Florbetapir PET. Additionally, CSF BACE1 and sAPPβ levels were positively associated with cortical thickness in multiple brain regions, and higher levels of sAPPβ were linked to increased cortical glucose metabolism in frontal and supramarginal areas. Interestingly, individuals with higher baseline levels of CSF BACE1 exhibited slower rates of brain volume reduction and cognitive worsening over time. This suggests that increased levels and activity of BACE1 may not be the determining factor for amyloid deposition, but instead, may be associated with increased neuronal activity and potentially providing protection against neurodegeneration in AD. Show less