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The phenotypic switch of vascular smooth cells (VSMCs) from a contractile to a synthetic state is associated with the development and progression of aortic aneurysm (AA). However, the mechanism underlying this process remains unclear. In this issue of the JCI, Song et al. identified SLC44A2 as a regulator of the phenotypic switch in VSMCs. Inhibition of SLC44A2 facilitated the switch to the synthetic state, contributing to the development of AA. Mechanistically, SLC44A2 interacted with NRP1 and ITGB3 to activate the TGF-ß/SMAD signaling pathway, resulting in VSMCs with a contractile phenotype. Furthermore, VSMC-specific SLC44A2 overexpression by genetic or pharmacological manipulation reduced AA in mouse models. These findings suggest the potential of targeting the SLC44A2 signaling pathway for AA prevention and treatment.
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Aneurisma Aórtico , Músculo Liso Vascular , Miócitos de Músculo Liso , Transdução de Sinais , Animais , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/patologia , Aneurisma Aórtico/metabolismo , Aneurisma Aórtico/patologia , Aneurisma Aórtico/genética , Camundongos , Miócitos de Músculo Liso/metabolismo , Miócitos de Músculo Liso/patologia , Humanos , Fenótipo , Fator de Crescimento Transformador beta/metabolismo , Fator de Crescimento Transformador beta/genética , Integrina beta3/metabolismo , Integrina beta3/genética , Proteínas de Membrana Transportadoras/metabolismo , Proteínas de Membrana Transportadoras/genética , Neuropilina-1/metabolismo , Neuropilina-1/genéticaRESUMO
As a pathological hallmark of type 2 diabetes mellitus (T2DM), islet amyloid is formed by the aggregation of islet amyloid polypeptide (IAPP). Endoplasmic reticulum (ER) stress interacts with IAPP aggregates and has been implicated in the pathogenesis of T2DM. To examine the role of ER stress in T2DM, we cloned the hIAPP promoter and analyzed its promoter activity in human ß-cells. We found that ER stress significantly enhanced hIAPP promoter activity and expression in human ß-cells via triggering X-box binding protein 1 (XBP1) splicing. We identified a binding site of XBP1 in the hIAPP promoter. Disruption of this binding site by substitution or deletion mutagenesis significantly diminished the effects of ER stress on hIAPP promoter activity. Blockade of XBP splicing by MKC3946 treatment inhibited ER stress-induced hIAPP up-regulation and improved human ß-cell survival and function. Our study uncovers a link between ER stress and IAPP at the transcriptional level and may provide novel insights into the role of ER stress in IAPP cytotoxicity and the pathogenesis of T2DM.
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BACKGROUND: Alpha-lipoic acid (ALA) has a neuroprotective effect on neurodegenerative diseases. In the clinic, ALA can improve cognitive impairments in patients with Alzheimer's disease (AD) and other dementias. Animal studies have confirmed the anti-amyloidosis effect of ALA, but its underlying mechanism remains unclear. In particular, the role of ALA in amyloid-ß precursor protein (APP) metabolism has not been fully elucidated. OBJECTIVE: To investigate whether ALA can reduce the amyloidogenic effect of APP in a transgenic mouse model of AD, and to study the mechanism underlying this effect. METHODS: ALA was infused into 2-month-old APP23/PS45 transgenic mice for 4 consecutive months and their cognitive function and AD-like pathology were then evaluated. An ALA drug concentration gradient was applied to 20E2 cells in vitro to evaluate its effect on the expression of APP proteolytic enzymes and metabolites. The mechanism by which ALA affects APP processing was studied using GI254023X, an inhibitor of A Disintegrin and Metalloproteinase 10 (ADAM10), as well as the mitochondrial toxic drug carbonyl cyanide m-chlorophenylhydrazone (CCCP). RESULTS: Administration of ALA ameliorated amyloid plaque neuropathology in the brain tissue of APP23/PS45 mice and reduced learning and memory impairment. ALA also increased the expression of ADAM10 in 20E2 cells and the non-amyloidogenic processing of APP to produce the 83 amino acid C-terminal fragment (C83). In addition to activating autophagy, ALA also significantly promoted mitophagy. BNIP3L-knockdown reduced the mat/pro ratio of ADAM10. By using CCCP, ALA was found to regulate BNIP3L-mediated mitophagy, thereby promoting the α-cleavage of APP. CONCLUSIONS: The enhanced α-secretase cleavage of APP by ADAM10 is the primary mechanism through which ALA ameliorates the cognitive deficits in APP23/PS45 transgenic mice. BNIP3L-mediated mitophagy contributes to the anti-amyloid properties of ALA by facilitating the maturation of ADAM10. This study provides novel experimental evidence for the treatment of AD with ALA.
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Proteína ADAM10 , Secretases da Proteína Precursora do Amiloide , Precursor de Proteína beta-Amiloide , Disfunção Cognitiva , Camundongos Transgênicos , Mitofagia , Ácido Tióctico , Animais , Ácido Tióctico/farmacologia , Mitofagia/efeitos dos fármacos , Proteína ADAM10/metabolismo , Camundongos , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Disfunção Cognitiva/tratamento farmacológico , Disfunção Cognitiva/metabolismo , Secretases da Proteína Precursora do Amiloide/metabolismo , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/metabolismo , Doença de Alzheimer/genética , Modelos Animais de Doenças , Proteínas de Membrana/metabolismo , Proteínas de Membrana/genética , Fármacos Neuroprotetores/farmacologia , Camundongos Endogâmicos C57BL , MasculinoRESUMO
The single nucleotide polymorphism (SNP)-rs6922617 in the triggering receptor expressed on myeloid cells (TREM) gene cluster is a potential risk factor for Alzheimer's disease (AD). Here, we examined whether rs6922617 is associated with AD-defining neuropathological hallmarks and memory performance. We assessed the interaction between the variant rs6922617 and levels of beta-amyloid (Aß), tau pathology, neurodegeneration, namely amyloid-tau-neurodegeneration (ATN) framework, and cognition functions in 660 Healthy controls (HCs), 794 mild cognitively impaired (MCI), and 272 subjects with AD. We employed linear regression and linear mixed models to examine the association. Here we find that the SNP-rs6922617 in the TREM gene cluster is associated with a higher global amyloid-ligands positron emission tomography (Aß-PET) burden and lower Fluorodeoxyglucose positron emission tomography (FDG-PET) load. Interestingly, rs6922617 risk allele carriers exhibit a significantly reduced tau accumulation compared to the non-carriers, indicating a discrepant association with Aß and tau pathologies. Though the participants carrying the rs6922617 risk allele do not show a correlation with poorer cognitive performance, stronger neuropathological phenotypes, and memory impairments are evident in ApoE ε4 carriers with the rs6922617 risk allele. These results support the notion that the SNP-rs6922617 in the TREM gene cluster is associated with AD-related neuropathological hallmarks, such as Aß and FDG-mediated neurodegeneration, rather than tau accumulation. While the direct association with memory impairment in the Alzheimer's continuum remains inconclusive, our findings suggest a potential role of rs6922617 in facilitating neuropathology hallmarks.
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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 in vitro and in vivo. In the in vitro experiment, SIL1 was either overexpressed or knocked down in cells stably expressing the human Swedish mutant APP695. In the in vivo experiment, AAV-SIL1-EGFP or AAV-EGFP was microinjected into APP23/PS45 mice and their wild-type littermates. Western blotting (WB), immunohistochemistry, RNA sequencing (RNA-seq), and behavioral experiments were performed to evaluate the relevant parameters. Results indicated that SIL1 expression decreased in APP23/PS45 mice. Overexpression of SIL1 significantly decreased the protein levels of APP, presenilin-1 (PS1), and C-terminal fragments (CTFs) of APP in vivo and in vitro. Conversely, knockdown of SIL1 increased the protein levels of APP, ß-site APP cleavage enzyme 1 (BACE1), PS1, and CTFs, as well as APP mRNA expression in 2EB2 cells. Furthermore, SIL1 overexpression reduced the number of senile plaques in APP23/PS45 mice. Importantly, Y-maze and Morris Water maze tests demonstrated that SIL1 overexpression improved cognitive impairment in APP23/PS45 mice. These findings indicate that SIL1 improves cognitive impairment in APP23/PS45 mice by inhibiting APP amyloidogenic processing and suggest that SIL1 is a potential therapeutic target for AD by modulating APP processing.
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Precursor de Proteína beta-Amiloide , Disfunção Cognitiva , Camundongos Transgênicos , Animais , Precursor de Proteína beta-Amiloide/metabolismo , Precursor de Proteína beta-Amiloide/genética , Camundongos , Disfunção Cognitiva/metabolismo , Disfunção Cognitiva/genética , Peptídeos beta-Amiloides/metabolismo , Presenilina-1/genética , Presenilina-1/metabolismo , Regulação da Expressão Gênica , Doença de Alzheimer/metabolismo , Doença de Alzheimer/genética , HumanosRESUMO
AIMS: Islet cell autoantigen 1 (ICA1) is involved in autoimmune diseases and may affect synaptic plasticity as a neurotransmitter. Databases related to Alzheimer's disease (AD) have shown decreased ICA1 expression in patients with AD. However, the role of ICA1 in AD remains unclear. Here, we report that ICA1 expression is decreased in the brains of patients with AD and an AD mouse model. RESULTS: The ICA1 increased the expression of amyloid precursor protein (APP), disintegrin and metalloprotease 10 (ADAM10), and disintegrin and metalloprotease 17 (ADAM17), but did not affect protein half-life or mRNA levels. Transcriptome sequencing analysis showed that ICA1 regulates the G protein-coupled receptor signaling pathway. The overexpression of ICA1 increased PKCα protein levels and phosphorylation. CONCLUSION: Our results demonstrated that ICA1 shifts APP processing to non-amyloid pathways by regulating the PICK1-PKCα signaling pathway. Thus, this study suggests that ICA1 is a novel target for the treatment of AD.
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Doença de Alzheimer , Precursor de Proteína beta-Amiloide , Proteína Quinase C-alfa , Transdução de Sinais , Precursor de Proteína beta-Amiloide/metabolismo , Precursor de Proteína beta-Amiloide/genética , Animais , Proteína Quinase C-alfa/metabolismo , Proteína Quinase C-alfa/genética , Transdução de Sinais/fisiologia , Humanos , Doença de Alzheimer/metabolismo , Doença de Alzheimer/genética , Camundongos , Proteínas de Transporte/metabolismo , Proteínas de Transporte/genética , Proteínas Nucleares/metabolismo , Proteínas Nucleares/genética , Masculino , Camundongos Transgênicos , Feminino , Camundongos Endogâmicos C57BL , Secretases da Proteína Precursora do Amiloide/metabolismo , Secretases da Proteína Precursora do Amiloide/genética , Encéfalo/metabolismo , Proteínas de Ciclo CelularRESUMO
Background: Maternal education is one of key factors affecting nurturing environment which significantly impacts children's height levels throughout their developmental stages. However, the influence of maternal education on children's height is less studied. This study aims to investigate the dynamic influence of maternal education on children's height among Chinese children aged 0-18 years. Methods: Children undergoing health examinations from January 2021 to September 2023 were included in this study. Clinical information including height, weight, maternal pregnancy history, blood specimens for bone metabolism-related indicators and maternal education level was collected. Children's height was categorized into 14 groups based on age and gender percentiles, following WHO 2006 growth standards. One-way analysis of variance (ANOVA), linear regression, chi-square test and Fisher's exact test were applied for data analysis. Results: A total of 6269 samples were collected, including 3654 males and 2615 females, with an average age of 8.38 (3.97) for males and 7.89 (3.55) for females. Significant correlations between maternal education level, birth weight, birth order, weight percentile, vitamin D, serum phosphorus, alkaline phosphatase levels, and children's height were identified. Birth weight's influence on height varied across age groups. Compared with normal birth weight children, low birth weight children exhibited catch-up growth within the first 6 years and a subsequent gradual widening of the height gap from 6 to 18 years old. Remarkably, the impact of maternal education on height became more pronounced among children above 3-6 years old, which can mitigate the effect of low birth weight on height. Conclusion: We found that weight percentile, birth weight, birth order, bone marker levels, and maternal education level have significant effect on height. Maternal education attenuates the impact of low birth weight on height. The findings indicated that maternal education plays a consistent and critical role in promoting robust and healthy growth.
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Cerebrovascular diseases (CVDs) are a major threat to global health. Elucidation of the molecular mechanisms underlying the pathology of CVDs is critical for the development of efficacious preventative and therapeutic approaches. Accumulating studies have highlighted the significance of ubiquitin-modifying enzymes (UMEs) in the regulation of CVDs. UMEs are a group of enzymes that orchestrate ubiquitination, a post-translational modification tightly involved in CVDs. Functionally, UMEs regulate multiple pathological processes in ischemic and hemorrhagic stroke, moyamoya disease, and atherosclerosis. Considering the important roles of UMEs in CVDs, they may become novel druggable targets for these diseases. Besides, techniques applying UMEs, such as proteolysis-targeting chimera and deubiquitinase-targeting chimera, may also revolutionize the therapy of CVDs in the future.
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Transtornos Cerebrovasculares , Humanos , Transtornos Cerebrovasculares/tratamento farmacológico , Transtornos Cerebrovasculares/metabolismo , Ubiquitina/metabolismo , UbiquitinaçãoRESUMO
Diphthamide is a modified histidine residue unique for eukaryotic translation elongation factor 2 (eEF2), a key ribosomal protein. Loss of this evolutionarily conserved modification causes developmental defects through unknown mechanisms. In a patient with compound heterozygous mutations in Diphthamide Biosynthesis 1 (DPH1) and impaired eEF2 diphthamide modification, we observe multiple defects in neural crest (NC)-derived tissues. Knockin mice harboring the patient's mutations and Xenopus embryos with Dph1 depleted also display NC defects, which can be attributed to reduced proliferation in the neuroepithelium. DPH1 depletion facilitates dissociation of eEF2 from ribosomes and association with p53 to promote transcription of the cell cycle inhibitor p21, resulting in inhibited proliferation. Knockout of one p21 allele rescues the NC phenotypes in the knockin mice carrying the patient's mutations. These findings uncover an unexpected role for eEF2 as a transcriptional coactivator for p53 to induce p21 expression and NC defects, which is regulated by diphthamide modification.
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Inibidor de Quinase Dependente de Ciclina p21 , Histidina , Histidina/análogos & derivados , Antígenos de Histocompatibilidade Menor , Crista Neural , Fator 2 de Elongação de Peptídeos , Proteína Supressora de Tumor p53 , Proteínas Supressoras de Tumor , Animais , Crista Neural/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Proteína Supressora de Tumor p53/genética , Humanos , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Inibidor de Quinase Dependente de Ciclina p21/genética , Camundongos , Fator 2 de Elongação de Peptídeos/metabolismo , Fator 2 de Elongação de Peptídeos/genética , Histidina/metabolismo , Ribossomos/metabolismo , Mutação , Proliferação de Células , Xenopus laevis , Feminino , Técnicas de Introdução de Genes , Xenopus , Masculino , Camundongos KnockoutRESUMO
AIM: This study assessed the efficacy and safety of co-administering retagliptin and henagliflozin versus individual agents at corresponding doses in patients with type 2 diabetes mellitus who were inadequately controlled with metformin. METHODS: This multicentre, phase 3 trial consisted of a 24-week, randomized, double-blind, active-controlled period. Patients with glycated haemoglobin (HbA1c) levels between 7.5% and 10.5% were randomized to receive once-daily retagliptin 100 mg (R100; n = 155), henagliflozin 5 mg (H5; n = 156), henagliflozin 10 mg (H10; n = 156), co-administered R100/H5 (n = 155), or R100/H10 (n = 156). The primary endpoint was the change in HbA1c from baseline to week 24. RESULTS: Based on the primary estimand, the least squares mean reductions in HbA1c at week 24 were significantly greater in the R100/H5 (-1.51%) and R100/H10 (-1.54%) groups compared with those receiving the corresponding doses of individual agents (-0.98% for R100, -0.86% for H5 and -0.95% for H10, respectively; p < .0001 for all pairwise comparisons). Achievement of HbA1c <7.0% at week 24 was observed in 27.1% of patients in the R100 group, 21.2% in the H5 group, 24.4% in the H10 group, 57.4% in the R100/H5 group and 56.4% in the R100/H10 group. Reductions in fasting plasma glucose and 2-h postprandial glucose were also more pronounced in the co-administration groups compared with the individual agents at corresponding doses. Decreases in body weight and systolic blood pressure were greater in the groups containing henagliflozin than in the R100 group. The incidence rates of adverse events were similar across all treatment groups, with no reported episodes of severe hypoglycaemia. CONCLUSIONS: For patients with type 2 diabetes mellitus inadequately controlled by metformin monotherapy, the co-administration of retagliptin and henagliflozin yielded more effective glycaemic control through 24 weeks compared with the individual agents at their corresponding doses.
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Glicemia , Diabetes Mellitus Tipo 2 , Quimioterapia Combinada , Hemoglobinas Glicadas , Hipoglicemiantes , Metformina , Humanos , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/sangue , Masculino , Pessoa de Meia-Idade , Feminino , Método Duplo-Cego , Metformina/administração & dosagem , Metformina/uso terapêutico , Hemoglobinas Glicadas/análise , Hemoglobinas Glicadas/efeitos dos fármacos , Hemoglobinas Glicadas/metabolismo , Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/uso terapêutico , Glicemia/efeitos dos fármacos , Glicemia/metabolismo , Idoso , Adulto , Resultado do TratamentoRESUMO
Mutations in the Contactin-associated protein-like 2 (CNTNAP2) gene are associated with autism spectrum disorder (ASD), and ectodomain shedding of the CNTNAP2 protein plays a role in its function. However, key enzymes involved in the C-terminal cleavage of CNTNAP2 remain largely unknown, and the effect of ASD-associated mutations on this process and its role in ASD pathogenesis remain elusive. In this report we showed that CNTNAP2 undergoes sequential cleavages by furin, ADAM10/17-dependent α-secretase and presenilin-dependent γ-secretase. We identified that the cleavage sites of ADAM10 and ADAM17 in CNTNAP2 locate at its C-terminal residue I79 and L96, and the main α-cleavage product C79 by ADAM10 is required for the subsequent γ-secretase cleavage to generate CNTNAP2 intracellular domain (CICD). ASD-associated CNTNAP2 mutations impair the α-cleavage to generate C79, and the inhibition leads to ASD-like repetitive and social behavior abnormalities in the Cntnap2-I1254T knock-in mice. Finally, exogenous expression of C79 improves autism-like phenotypes in the Cntnap2-I1254T knock-in and Cntnap2-/- knockout mice. This data demonstrates that the α-secretase is essential for CNTNAP2 processing and its function. Our study indicates that inhibition of the cleavage by pathogenic mutations underlies ASD pathogenesis, and upregulation of its C-terminal fragments could have therapeutical potentials for ASD treatment.
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Transtorno do Espectro Autista , Transtorno Autístico , Animais , Camundongos , Secretases da Proteína Precursora do Amiloide/genética , Transtorno do Espectro Autista/genética , Mutação/genética , Camundongos Knockout , Contactinas/genética , Fenótipo , Proteínas de Membrana/genética , Proteínas do Tecido Nervoso/genéticaRESUMO
There have been no previous reports of hippocampal radiomics features associated with biological functions in Alzheimer's Disease (AD). This study aims to develop and validate a hippocampal radiomics model from structural magnetic resonance imaging (MRI) data for identifying patients with AD, and to explore the mechanism underlying the developed radiomics model using peripheral blood gene expression. In this retrospective multi-study, a radiomics model was developed based on the radiomics discovery group (n = 420) and validated in other cohorts. The biological functions underlying the model were identified in the radiogenomic analysis group using paired MRI and peripheral blood transcriptome analyses (n = 266). Mediation analysis and external validation were applied to further validate the key module and hub genes. A 12 radiomics features-based prediction model was constructed and this model showed highly robust predictive power for identifying AD patients in the validation and other three cohorts. Using radiogenomics mapping, myeloid leukocyte and neutrophil activation were enriched, and six hub genes were identified from the key module, which showed the highest correlation with the radiomics model. The correlation between hub genes and cognitive ability was confirmed using the external validation set of the AddneuroMed dataset. Mediation analysis revealed that the hippocampal radiomics model mediated the association between blood gene expression and cognitive ability. The hippocampal radiomics model can accurately identify patients with AD, while the predictive radiomics model may be driven by neutrophil-related biological pathways.
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Doença de Alzheimer , Humanos , Estudos de Coortes , Estudos Retrospectivos , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/genética , Radiômica , Hipocampo/diagnóstico por imagem , Imageamento por Ressonância MagnéticaRESUMO
BACKGROUND: A considerable number of individuals infected with COVID-19 experience residual symptoms after the acute phase. However, the correlation between residual symptoms and psychological distress and underlying mechanisms are scarcely studied. We aim to explore the association between residual symptoms of COVID-19 and psychological distress, specifically depression, anxiety, and fear of COVID-19, and examine the role of risk perception and intolerance of uncertainty in the association. METHODS: A cross-sectional survey was conducted by online questionnaire-based approach in mid-January 2023. Self-reported demographic characteristics, COVID-19-related information, and residual symptoms were collected. Depression, anxiety, fear, risk perception and intolerance of uncertainty were evaluated using the Patient Health Questionnaire-9 (PHQ-9), Generalized Anxiety Disorder-7 (GAD-7), Fear of COVID-19 Scale (FCV-19S), COVID-19 Risk Perception Scale and Intolerance of Uncertainty Scale-12 (IUS-12), respectively. Linear regression analyses were conducted to explore the associations. A moderated mediation model was then constructed to examine the role of risk perception of COVID-19 and intolerance of uncertainty in the association between residual symptoms and psychological distress. RESULTS: 1735 participants effectively completed the survey. 34.9% of the patients experienced residual symptoms after acute phase of COVID-19. Psychological distress was markedly increased by COVID-19 infection, while residual symptoms had a significant impact on psychological distress (Ps < 0.001), including depression (ß = 0.23), anxiety (ß = 0.21), and fear of COVID-19 (ß = 0.14). Risk perception served as a mediator between residual symptoms and all forms of psychological distress, while intolerance of uncertainty moderated the effect of risk perception on depression and anxiety. CONCLUSION: A considerable proportion of patients experience residual symptoms after acute phase of COVID-19, which have a significant impact on psychological distress. Risk perception and intolerance of uncertainty play a moderated-mediation role in the association between residual symptoms and depression/anxiety. It highly suggests that effective treatment for residual symptoms, maintaining appropriate risk perception and improving intolerance of uncertainty are critical strategies to alleviate COVID-19 infection-associated psychological distress.
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COVID-19 , Angústia Psicológica , Humanos , Estudos Transversais , Incerteza , Depressão/psicologia , Ansiedade/psicologia , PercepçãoRESUMO
Alzheimer's disease (AD) is a leading cause of dementia in the elderly. Mitogen-activated protein kinase phosphatase 1 (MKP-1) plays a neuroprotective role in AD. However, the molecular mechanisms underlying the effects of MKP-1 on AD have not been extensively studied. MicroRNAs (miRNAs) regulate gene expression at the post-transcriptional level, thereby repressing mRNA translation. Here, we reported that the microRNA-429-3p (miR-429-3p) was significantly increased in the brain of APP23/PS45 AD model mice and N2AAPP AD model cells. We further found that miR-429-3p could downregulate MKP-1 expression by directly binding to its 3'-untranslated region (3' UTR). Inhibition of miR-429-3p by its antagomir (A-miR-429) restored the expression of MKP-1 to a control level and consequently reduced the amyloidogenic processing of APP and Aß accumulation. More importantly, intranasal administration of A-miR-429 successfully ameliorated the deficits of hippocampal CA1 long-term potentiation and spatial learning and memory in AD model mice by suppressing extracellular signal-regulated kinase (ERK1/2)-mediated GluA1 hyperphosphorylation at Ser831 site, thereby increasing the surface expression of GluA1-containing α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs). Together, these results demonstrate that inhibiting miR-429-3p to upregulate MKP-1 effectively improves cognitive and synaptic functions in AD model mice, suggesting that miR-429/MKP-1 pathway may be a novel therapeutic target for AD treatment.
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Proprotein convertase subtilisin/kexin type 6 (PCSK6) is a calcium-dependent serine proteinase that regulates the proteolytic activity of various precursor proteins and facilitates protein maturation. Dysregulation of PCSK6 expression or function has been implicated in several pathological processes including nervous system diseases. However, whether and how PCSK6 is involved in the pathogenesis of Alzheimer's disease (AD) remains unclear. In this study, we reported that the expression of PCSK6 was significantly increased in the brain tissues of postmortem AD patients and APP23/PS45 transgenic AD model mice, as well as N2AAPP cells. Genetic knockdown of PCSK6 reduced amyloidogenic processing of APP in N2AAPP cells by suppressing the activation of membrane-type 5-matrix metalloproteinase (MT5-MMP), referred to as η-secretase. We further found that PCSK6 cleaved and activated MT5-MMP by recognizing the RRRNKR sequence in its N-terminal propeptide domain in N2A cells. The mutation or knockout of this cleavage motif prevented PCSK6 from interacting with MT5-MMP and performing cleavage. Importantly, genetic knockdown of PCSK6 with adeno-associated virus (AAV) reduced Aß production and ameliorated hippocampal long-term potentiation (LTP) and long-term spatial learning and memory in APP23/PS45 transgenic mice. Taken together, these results demonstrate that genetic knockdown of PCSK6 effectively alleviate AD-related pathology and cognitive impairments by inactivating MT5-MMP, highlighting its potential as a novel therapeutic target for AD treatment.
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Doença de Alzheimer , Animais , Humanos , Camundongos , Doença de Alzheimer/metabolismo , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Modelos Animais de Doenças , Camundongos Transgênicos , Pró-Proteína Convertases/genética , Pró-Proteína Convertases/metabolismo , Proteólise , Serina Endopeptidases/metabolismo , Aprendizagem EspacialRESUMO
Hepatocellular carcinoma (HCC) is a significant contributor to global cancer-related deaths, leading to high mortality rates. However, the pathogenesis of HCC remains unclear. In this research, by the bioinformatics data analysis, we found that elevated CSTB expression correlated with advanced disease and predicted diminished overall survival (OS) in HCC patients. We subsequently verified the oncogenic role of CSTB as well as the potential underlying mechanisms in HCC through a series of in vitro experiments, such as CCK-8 assays, cloning assays, flow cytometry, Transwell assays, and western blotting. Our findings illustrated that the silencing of CSTB effectively suppressed cellular proliferation by inducing cell cycle arrest in the G2 phase and impaired HCC cell invasion and migration by stimulating epithelial-mesenchymal transition (EMT). Additionally, we analyzed the pathways enriched in HCC using RNA sequencing and found that the ERK/AKT/mTOR signaling pathway was related to increased CSTB expression in HCC. Finally, we confirmed the tumorigenic role of CSTB via in vivo experiments. Thus, our findings revealed that silencing CSTB inhibited the HCC progression via the ERK/AKT/mTOR signaling pathway, highlighting new perspectives for investigating the mechanisms of HCC.
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Inflammasomes are large protein complexes that play a major role in sensing inflammatory signals and triggering the innate immune response. Each inflammasome complex has three major components: an upstream sensor molecule that is connected to a downstream effector protein such as caspase-1 through the adapter protein ASC. Inflammasome formation typically occurs in response to infectious agents or cellular damage. The active inflammasome then triggers caspase-1 activation, followed by the secretion of pro-inflammatory cytokines and pyroptotic cell death. Aberrant inflammasome activation and activity contribute to the development of diabetes, cancer, and several cardiovascular and neurodegenerative disorders. As a result, recent research has increasingly focused on investigating the mechanisms that regulate inflammasome assembly and activation, as well as the potential of targeting inflammasomes to treat various diseases. Multiple clinical trials are currently underway to evaluate the therapeutic potential of several distinct inflammasome-targeting therapies. Therefore, understanding how different inflammasomes contribute to disease pathology may have significant implications for developing novel therapeutic strategies. In this article, we provide a summary of the biological and pathological roles of inflammasomes in health and disease. We also highlight key evidence that suggests targeting inflammasomes could be a novel strategy for developing new disease-modifying therapies that may be effective in several conditions.
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Imunidade Inata , Inflamassomos , Humanos , Inflamassomos/metabolismo , Morte Celular , Piroptose , Caspase 1/genéticaRESUMO
Amyloid ß protein (Aß) is a critical factor in the pathogenesis of Alzheimer's disease (AD). Aß induces apoptosis, and gasdermin-E (GSDME) expression can switch apoptosis to pyroptosis. In this study, we demonstrated that GSDME was highly expressed in the hippocampus of APP23/PS45 mouse models compared to that in age-matched wild-type mice. Aß treatment induced pyroptosis by active caspase-3/GSDME in SH-SY5Y cells. Furthermore, the knockdown of GSDME improved the cognitive impairments of APP23/PS45 mice by alleviating inflammatory response. Our findings reveal that GSDME, as a modulator of Aß and pyroptosis, plays a potential role in Alzheimer's disease pathogenesis and shows that GSDME is a therapeutic target for AD.