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How to fuse low-level and high-level features effectively is crucial to improving the accuracy of medical image segmentation. Most CNN-based segmentation models on this topic usually adopt attention mechanisms to achieve the fusion of different level features, but they have not effectively utilized the guided information of high-level features, which is often highly beneficial to improve the performance of the segmentation model, to guide the extraction of low-level features. To address this problem, we design multiple guided modules and develop a boundary-guided filter network (BGF-Net) to obtain more accurate medical image segmentation. To the best of our knowledge, this is the first time that boundary guided information is introduced into the medical image segmentation task. Specifically, we first propose a simple yet effective channel boundary guided module to make the segmentation model pay more attention to the relevant channel weights. We further design a novel spatial boundary guided module to complement the channel boundary guided module and aware of the most important spatial positions. Finally, we propose a boundary guided filter to preserve the structural information from the previous feature map and guide the model to learn more important feature information. Moreover, we conduct extensive experiments on skin lesion, polyp, and gland segmentation datasets including ISIC 2016, CVC-EndoSceneStil and GlaS to test the proposed BGF-Net. The experimental results demonstrate that BGF-Net performs better than other state-of-the-art methods.
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Procesamiento de Imagen Asistido por Computador , AprendizajeRESUMEN
Segmenting the optic disc (OD) and optic cup (OC) is crucial to accurately detect changes in glaucoma progression in the elderly. Recently, various convolutional neural networks have emerged to deal with OD and OC segmentation. Due to the domain shift problem, achieving high-accuracy segmentation of OD and OC from different domain datasets remains highly challenging. Unsupervised domain adaptation has taken extensive focus as a way to address this problem. In this work, we propose a novel unsupervised domain adaptation method, called entropy and distance-guided super self-ensembling (EDSS), to enhance the segmentation performance of OD and OC. EDSS is comprised of two self-ensembling models, and the Gaussian noise is added to the weights of the whole network. Firstly, we design a super self-ensembling (SSE) framework, which can combine two self-ensembling to learn more discriminative information about images. Secondly, we propose a novel exponential moving average with Gaussian noise (G-EMA) to enhance the robustness of the self-ensembling framework. Thirdly, we propose an effective multi-information fusion strategy (MFS) to guide and improve the domain adaptation process. We evaluate the proposed EDSS on two public fundus image datasets RIGA+ and REFUGE. Large amounts of experimental results demonstrate that the proposed EDSS outperforms state-of-the-art segmentation methods with unsupervised domain adaptation, e.g., the Dicemean score on three test sub-datasets of RIGA+ are 0.8442, 0.8772 and 0.9006, respectively, and the Dicemean score on the REFUGE dataset is 0.9154.
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Retinal vessel segmentation is very important for diagnosing and treating certain eye diseases. Recently, many deep learning-based retinal vessel segmentation methods have been proposed; however, there are still many shortcomings (e.g., they cannot obtain satisfactory results when dealing with cross-domain data or segmenting small blood vessels). To alleviate these problems and avoid overly complex models, we propose a novel network based on a multi-scale feature and style transfer (MSFST-NET) for retinal vessel segmentation. Specifically, we first construct a lightweight segmentation module named MSF-Net, which introduces the selective kernel (SK) module to increase the multi-scale feature extraction ability of the model to achieve improved small blood vessel segmentation. Then, to alleviate the problem of model performance degradation when segmenting cross-domain datasets, we propose a style transfer module and a pseudo-label learning strategy. The style transfer module is used to reduce the style difference between the source domain image and the target domain image to improve the segmentation performance for the target domain image. The pseudo-label learning strategy is designed to be combined with the style transfer module to further boost the generalization ability of the model. Moreover, we trained and tested our proposed MSFST-NET in experiments on the DRIVE and CHASE_DB1 datasets. The experimental results demonstrate that MSFST-NET can effectively improve the generalization ability of the model on cross-domain datasets and achieve improved retinal vessel segmentation results than other state-of-the-art methods.
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Procesamiento de Imagen Asistido por Computador , Vasos Retinianos , Vasos Retinianos/diagnóstico por imagen , AlgoritmosRESUMEN
BACKGROUND: The goal of this study was to create a nomogram using routine parameters to predict leptomeningeal metastases (LMs) in advanced lung adenocarcinoma (LAC) patients to prevent needless exams or lumbar punctures and to assist in accurately diagnosing LMs. METHODS: Two hundred and seventy-three patients with LMs and brain metastases were retrospectively reviewed and divided into derivation (n = 191) and validation (n = 82) cohorts using a 3:7 random allocation. All LAC patients with LMs had positive cerebrospinal fluid cytology results and brain metastases confirmed by magnetic resonance imaging. Binary logistic regression with backward stepwise selection was used to identify significant characteristics. A predictive nomogram based on the logistic model was assessed through receiver operating characteristic curves. The validation cohort and Hosmer-Lemeshow test were used for internal validation of the nomogram. RESULTS: Five clinicopathological parameters, namely, gene mutations, surgery at the primary lung cancer site, clinical symptoms of the head, N stage, and therapeutic strategy, were used as predictors of LMs. The area under the curve was 0.946 (95% CI 0.912-0.979) for the training cohort and 0.861 (95% CI 0.761-0.961) for the internal validation cohort. There was no significant difference in performance between the two cohorts (p = 0.116). In the internal validation, calibration plots revealed that the nomogram predictions were well suited to the actual outcomes. CONCLUSIONS: We created a user-friendly nomogram to predict LMs in advanced lung cancer patients, which could help guide treatment decisions and reduce unnecessary lumbar punctures.
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Adenocarcinoma del Pulmón , Neoplasias Pulmonares , Metástasis Linfática , Nomogramas , Humanos , Masculino , Femenino , Persona de Mediana Edad , Adenocarcinoma del Pulmón/patología , Neoplasias Pulmonares/patología , Estudios Retrospectivos , Anciano , Neoplasias Meníngeas/secundario , Neoplasias Meníngeas/líquido cefalorraquídeo , Adulto , Neoplasias Encefálicas/secundario , Neoplasias Encefálicas/diagnóstico por imagen , Neoplasias Encefálicas/líquido cefalorraquídeo , Curva ROC , Imagen por Resonancia MagnéticaRESUMEN
Objectives: To analyze and describe the spatiotemporal trends of Low back pain (LBP) burdens from 1990 to 2019 and anticipate the following decade's incidence. Methods: Using data from the Global Burden of Disease (GBD) 2019 Study, we described net drifts, local drifts, age effects, and period cohort effects in incidence and forecasted incidence rates and cases by sex from 2020 to 2029 using the Nordpred R package. Results: LBP remained the leading cause of the musculoskeletal disease burden globally and across all socio-demographic index (SDI) regions. China is the top country. For recent periods, high-SDI countries faced unfavorable or worsening risks. The relative risk of incidence showed improving trends over time and in successively younger birth cohorts amongst low-middle-, middle- and high-middle-SDI countries. Additionally, the age-standardized incidence rates (ASIR) of LBP in both sexes globally showed a decreasing trend, but the incident cases would increase from 223 to 253 million overall in the next decade. Conclusion: As the population ages, incident cases will rise but ASIR will fall. To minimise LBP, public awareness and disease prevention and control are needed.
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Dolor de la Región Lumbar , Femenino , Humanos , Masculino , China/epidemiología , Carga Global de Enfermedades , Incidencia , Dolor de la Región Lumbar/epidemiologíaRESUMEN
RATIONALE AND OBJECTIVES: This study aimed to develop a diagnostic model based on clinical and CT features for identifying clear cell renal cell carcinoma (ccRCC) in small renal masses (SRMs). MATERIAL AND METHODS: This retrospective multi-centre study enroled patients with pathologically confirmed SRMs. Data from three centres were used as training set (n = 229), with data from one centre serving as an independent test set (n = 81). Univariate and multivariate logistic regression analyses were utilised to screen independent risk factors for ccRCC and build the classification and regression tree (CART) diagnostic model. The area under the curve (AUC) was used to evaluate the performance of the model. To demonstrate the clinical utility of the model, three radiologists were asked to diagnose the SRMs in the test set based on professional experience and re-evaluated with the aid of the CART model. RESULTS: There were 310 SRMs in 309 patients and 71% (220/310) were ccRCC. In the testing cohort, the AUC of the CART model was 0.90 (95% CI: 0.81, 0.97). For the radiologists' assessment, the AUC of the three radiologists based on the clinical experience were 0.78 (95% CI:0.66,0.89), 0.65 (95% CI:0.53,0.76), and 0.68 (95% CI:0.57,0.79). With the CART model support, the AUC of the three radiologists were 0.93 (95% CI:0.86,0.97), 0.87 (95% CI:0.78,0.95) and 0.87 (95% CI:0.78,0.95). Interobserver agreement was improved with the CART model aids (0.323 vs 0.654, P < 0.001). CONCLUSION: The CART model can identify ccRCC with better diagnostic efficacy than that of experienced radiologists and improve diagnostic performance, potentially reducing the number of unnecessary biopsies.
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B-type natriuretic peptide (BNP) is a biomarker for heart failure, a serious and prevalent disease that requires rapid and accurate diagnosis. In this study, we developed a novel electrochemical biosensor for BNP detection based on CRISPR/Cas13a and chain substitution reaction. The biosensor consists of a DNA aptamer that specifically binds to BNP, a T7 RNA polymerase that amplifies the signal, a CRISPR/Cas13a system that cleaves the target RNA, and a two-dimensional DNA nanoprobe that generates an electrochemical signal. The biosensor exhibits high sensitivity, specificity, and stability, with a detection limit of 0.74 aM. The biosensor can also detect BNP in human serum samples with negligible interference, demonstrating its potential for clinical and point-of-care applications. This study presents a novel strategy for integrating CRISPR/Cas13a and chain substitution reaction into biosensor design, offering a versatile and effective platform for biomolecule detection.
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Técnicas Biosensibles , Sistemas CRISPR-Cas , Técnicas Electroquímicas , Péptido Natriurético Encefálico , Técnicas Biosensibles/métodos , Péptido Natriurético Encefálico/sangre , Péptido Natriurético Encefálico/química , Humanos , Sistemas CRISPR-Cas/genética , Límite de Detección , Aptámeros de Nucleótidos/químicaRESUMEN
BACKGROUND: MicroRNAs (miRNAs) are important non-coding RNA entities that affect gene expression and function by binding to target mRNAs, leading to degradation of the mRNAs or inhibiting their translation. MiRNAs are widely involved in a variety of biological processes, such as cell differentiation, development, metabolism, and apoptosis. In addition, miRNAs are associated with many diseases, including cancer. However, conventional detection techniques often suffer from shortcomings such as low sensitivity, so we need to develop a rapid and efficient detection strategy for accurate detection of miRNAs. RESULTS: We have developed an innovative homogeneous electrochemiluminescence (ECL) biosensor. This biosensor employs CRISPR/Cas12a gene editing technology for accurate and efficient detection of microRNA (miRNA). Compared to conventional technologies, this biosensor employs a unique homogeneous detection format that eliminates laborious probe fixation steps and greatly simplifies the detection process. By using two amplification techniques - isothermal amplification and T7 RNA polymerase amplification - the biosensor improves the sensitivity and specificity of the assay, providing excellent detection performance in the assay. This makes it possible to evaluate miRNA directly from a variety of biological samples such as cell lysates and diluted human serum. Experimental results convincingly demonstrate the extraordinary performance of this biosensor, including its extremely low detection limit of 1.27 aM, high sensitivity, reproducibility and stability. SIGNIFICANCE: The application of our constructed sensor in distinguishing between cancerous and non-cancerous cell lines highlights its potential for early cancer detection and monitoring. This innovative approach represents a major advancement in the field of miRNA detection, providing a user-friendly, cost-effective, and sensitive solution with broad implications for clinical diagnosis and patient care, especially in point-of-care settings.
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Técnicas Biosensibles , Sistemas CRISPR-Cas , Técnicas Electroquímicas , Mediciones Luminiscentes , MicroARNs , Humanos , Técnicas Biosensibles/métodos , MicroARNs/análisis , MicroARNs/sangre , MicroARNs/genética , Sistemas CRISPR-Cas/genética , Técnicas Electroquímicas/métodos , Límite de Detección , Proteínas Asociadas a CRISPR/genética , Proteínas Bacterianas , EndodesoxirribonucleasasRESUMEN
Lakes and reservoirs worldwide are experiencing a growing problem with harmful cyanobacterial blooms (HCBs), which have significant implications for ecosystem health and water quality. Algaecide is an effective way to control HCBs effectively. In this study, we applied an active substructure splicing strategy for rapid discovery of algicides. Through this strategy, we first optimized the structure of the lead compound S5, designed and synthesized three series of thioacetamide derivatives (series A, B, C), and then evaluated their algicidal activities. Finally, compound A3 with excellent performance was found, which accelerated the process of discovering and developing new algicides. The biological activity assay data showed that A3 had a significant inhibitory effect on M. aeruginosa. FACHB905 (EC50 = 0.46 µM) and Synechocystis sp. PCC6803 (EC50 = 0.95 µM), which was better than the commercial algicide prometryn (M. aeruginosa. FACHB905, EC50 = 6.52 µM; Synechocystis sp. PCC6803, EC50 = 4.64 µM) as well as better than lead compound S5 (M. aeruginosa. FACHB905, EC50 = 8.80 µM; Synechocystis sp. PCC6803, EC50 = 7.70 µM). The relationship between the surface electrostatic potential, chemical reactivity, and global electrophilicity of the compounds and their activities was discussed by density functional theory (DFT). Physiological and biochemical studies have shown that A3 might affect the photosynthesis pathway and antioxidant system in cyanobacteria, resulting in the morphological changes of cyanobacterial cells. Our work demonstrated that A3 might be a promising candidate for the development of novel algicides and provided a new active skeleton for the development of subsequent chemical algicides.
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Herbicidas , Synechocystis , Tioacetamida , Ecosistema , Herbicidas/químicaRESUMEN
Estrogens promote binge alcohol drinking and contribute to sex differences in alcohol use disorder. However, the mechanisms are largely unknown. This study aims to test if estrogens act on 5-hydroxytryptamine neurons in the dorsal raphe nucleus (5-HTDRN) to promote binge drinking. We found that female mice drank more alcohol than male mice in chronic drinking in the dark (DID) tests. This sex difference was associated with distinct alterations in mRNA expression of estrogen receptor α (ERα) and 5-HT-related genes in the DRN, suggesting a potential role of estrogen/ERs/5-HT signaling. In supporting this view, 5-HTDRN neurons from naïve male mice had lower baseline firing activity but higher sensitivity to alcohol-induced excitation compared to 5-HTDRN neurons from naïve female mice. Notably, this higher sensitivity was blunted by 17ß-estradiol treatment in males, indicating an estrogen-dependent mechanism. We further showed that both ERα and ERß are expressed in 5-HTDRN neurons, whereas ERα agonist depolarizes and ERß agonist hyperpolarizes 5-HTDRN neurons. Notably, both treatments blocked the stimulatory effects of alcohol on 5-HTDRN neurons in males, even though they have antagonistic effects on the activity dynamics. These results suggest that ERs' inhibitory effects on ethanol-induced burst firing of 5-HTDRN neurons may contribute to higher levels of binge drinking in females. Consistently, chemogenetic activation of ERα- or ERß-expressing neurons in the DRN reduced binge alcohol drinking. These results support a model in which estrogens act on ERα/ß to prevent alcohol-induced activation of 5-HTDRN neurons, which in return leads to higher binge alcohol drinking.
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Consumo Excesivo de Bebidas Alcohólicas , Receptor alfa de Estrógeno , Ratones , Femenino , Masculino , Animales , Receptor alfa de Estrógeno/agonistas , Receptor alfa de Estrógeno/genética , Receptor alfa de Estrógeno/metabolismo , Núcleo Dorsal del Rafe/metabolismo , Receptor beta de Estrógeno/agonistas , Receptor beta de Estrógeno/metabolismo , Serotonina/metabolismo , Estrógenos/farmacología , Etanol/farmacologíaRESUMEN
Free-feeding animals navigate complex nutritional landscapes in which food availability, cost, and nutritional value can vary markedly. Animals have thus developed neural mechanisms that enable the detection of nutrient restriction, and these mechanisms engage adaptive physiological and behavioral responses that limit or reverse this nutrient restriction. This review focuses specifically on dietary protein as an essential and independently defended nutrient. Adequate protein intake is required for life, and ample evidence exists to support an active defense of protein that involves behavioral changes in food intake, food preference, and food motivation, likely mediated by neural changes that increase the reward value of protein foods. Available evidence also suggests that the circulating hormone fibroblast growth factor 21 (FGF21) acts in the brain to coordinate these adaptive changes in food intake, making it a unique endocrine signal that drives changes in macronutrient preference in the context of protein restriction. This article is part of the Special Issue on "Food intake and feeding states".
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Ingestión de Alimentos , Factores de Crecimiento de Fibroblastos , Preferencias Alimentarias , Factores de Crecimiento de Fibroblastos/metabolismo , Animales , Preferencias Alimentarias/fisiología , Ingestión de Alimentos/fisiología , Humanos , Nutrientes , Proteínas en la Dieta/administración & dosificación , Adaptación Fisiológica/fisiología , Dieta con Restricción de Proteínas , Encéfalo/metabolismo , Encéfalo/fisiologíaRESUMEN
Thermogenic beige adipocytes are recognized as potential therapeutic targets for combating metabolic diseases. However, the metabolic advantages that they offer are compromised with aging. Here we show that treating mice with estrogen (E2), a hormone that decreases with age, can counteract the age-related decline in beige adipogenesis when exposed to cold temperature while concurrently enhancing energy expenditure and improving glucose tolerance in mice. Mechanistically, we found that nicotinamide phosphoribosyl transferase (NAMPT) plays a pivotal role in facilitating the formation of E2-induced beige adipocytes, which subsequently suppresses the onset of age-related endoplasmic reticulum (ER) stress. Furthermore, we found that targeting NAMPT signaling, either genetically or pharmacologically, can restore the formation of beige adipocytes by increasing the number of perivascular adipocyte progenitor cells. Conversely, the absence of NAMPT signaling prevents this process. Together, our findings shed light on the mechanisms regulating the age-dependent impairment of beige adipocyte formation and underscore the E2-NAMPT-controlled ER stress pathway as a key regulator of this process.
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Adipocitos Beige , Adipogénesis , Envejecimiento , Estrés del Retículo Endoplásmico , Estrógenos , Nicotinamida Fosforribosiltransferasa , Nicotinamida Fosforribosiltransferasa/metabolismo , Animales , Adipogénesis/efectos de los fármacos , Estrés del Retículo Endoplásmico/efectos de los fármacos , Ratones , Envejecimiento/efectos de los fármacos , Envejecimiento/fisiología , Estrógenos/metabolismo , Estrógenos/farmacología , Adipocitos Beige/efectos de los fármacos , Adipocitos Beige/metabolismo , Citocinas/metabolismo , Transducción de Señal/efectos de los fármacos , Femenino , Ratones Endogámicos C57BL , Metabolismo Energético/efectos de los fármacosRESUMEN
Dietary protein restriction induces adaptive changes in food preference, increasing protein consumption over carbohydrates or fat. We investigated whether motivation and reward signaling underpin these preferences. In an operant task, protein-restricted male mice increased their responding for liquid protein rewards, but not carbohydrate, fat, or sweet rewards. The protein restriction-induced increase in operant responding for protein was absent in Fgf21-KO mice and mice with neuron-specific deletion of the FGF21 co-receptor beta-Klotho (KlbCam2ka) mice. Fiber photometry recording of VTA dopamine neurons revealed that oral delivery of maltodextrin triggered a larger activation of dopamine neurons as compared to casein in control-fed mice, while casein produced a larger response in protein-restricted mice. This restriction-induced shift in nutrient-specific VTA dopamine signaling was lost in Fgf21-KO mice. These data demonstrate that FGF21 acts in the brain to induce a protein-specific appetite by specifically enhancing the reward value of protein-containing foods and the motivation to consume them.
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BACKGROUND: In Traditional Chinese Medicine (TCM) theory, cold dampness obstruction is one of the common syndromes of osteoarthritis. Therefore, in clinical practice, the main treatment methods are to dispel wind, remove dampness, and dissipate cold, used to treat knee osteoarthritis (KOA). This report describes a mulitercenter clinical study to assess Zhuifeng Tougu Capsule's efficacy and safety in the treatment of patients who are cold dampness obstruction syndrome in KOA, and to provide evidence-based medical for the rational use of Zhuifeng Tougu Capsules in clinical practice. METHODS: This randomized, parallel group controlled, double-blind, double dummy trial will include a total of 215 KOA patients who meet the study criteria. 215 patients underwent 1:1 randomisation, with 107 cases assigned the experimental group (Zhuifeng Tougu Capsules + Glucosamine Sulfate Capsules Simulator) and 108 assigned the control group (Glucosamine Sulfate Capsules + Zhuifeng Tougu Capsules Simulator). After enrolment, patients received 12 weeks of treatment. The main efficacy measure is the Western Ontario and McMaster University Osteoarthritis Index (WOMAC) pain score. Visual analogue scale (VAS) pain score, Self-condition assessment VAS score, WOMAC KOA score, TCM syndrome score and TCM syndrome efficacy, ESR level, CRP level, suprapatellar bursa effusion depth, use of rescue drugs, and safety indicators are secondary efficacy indicators. RESULTS: Compared with before treatment, WOMAC pain score, VAS pain score, Self-condition assessment VAS score, WOMAC KOA score, and TCM syndrome score decreased significantly in both groups (P < 0.01). Also, the experimental group showed significant differences in the above indicators compared to control (P < 0.01). However, after treatment, no significant differences were showed in the ESR level, CRP level, and suprapatellar bursa effusion depth between the two groups (P > 0.05). No any serious adverse effects showed in the experimental group and control group. CONCLUSIONS: Zhuifeng Tougu Capsules can effectively improve knee joint function and significantly alleviate the pain of KOA. TRIAL REGISTRATION: Clinical trial registration was completed with the China Clinical Trial Registration Center for this research protocol (No. ChiCTR2000028750) on January 2, 2020.
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The cerebellum, a phylogenetically ancient brain region, has long been considered strictly a motor control structure. Recent studies have implicated the cerebellum in cognition, sensation, emotion and autonomic function, making it an important target for further investigation. Here, we show that cerebellar Purkinje neurons in mice are activated by the hormone asprosin, leading to enhanced thirst, and that optogenetic or chemogenetic activation of Purkinje neurons induces rapid manifestation of water drinking. Purkinje neuron-specific asprosin receptor (Ptprd) deletion results in reduced water intake without affecting food intake and abolishes asprosin's dipsogenic effect. Purkinje neuron-mediated motor learning and coordination were unaffected by these manipulations, indicating independent control of two divergent functions by Purkinje neurons. Our results show that the cerebellum is a thirst-modulating brain area and that asprosin-Ptprd signaling may be a potential therapeutic target for the management of thirst disorders.
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Declined memory is a hallmark of Alzheimer's disease (AD). Experiments in rodents and human postmortem studies suggest that serotonin (5-hydroxytryptamine, 5-HT) plays a role in memory, but the underlying mechanisms are unknown. Here, we investigate the role of 5-HT 2C receptor (5-HT2CR) in regulating memory. Transgenic mice expressing a humanized HTR2C mutation exhibit impaired plasticity of hippocampal ventral CA1 (vCA1) neurons and reduced memory. Further, 5-HT neurons project to and synapse onto vCA1 neurons. Disruption of 5-HT synthesis in vCA1-projecting neurons or deletion of 5-HT2CRs in the vCA1 impairs neural plasticity and memory. We show that a selective 5-HT2CR agonist, lorcaserin, improves synaptic plasticity and memory in an AD mouse model. Cumulatively, we demonstrate that hippocampal 5-HT2CR signaling regulates memory, which may inform the use of 5-HT2CR agonists in the treatment of dementia.
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Enfermedad de Alzheimer , Memoria , Ratones Transgénicos , Plasticidad Neuronal , Receptor de Serotonina 5-HT2C , Animales , Humanos , Receptor de Serotonina 5-HT2C/metabolismo , Receptor de Serotonina 5-HT2C/genética , Memoria/efectos de los fármacos , Memoria/fisiología , Ratones , Plasticidad Neuronal/efectos de los fármacos , Enfermedad de Alzheimer/metabolismo , Hipocampo/metabolismo , Hipocampo/efectos de los fármacos , Serotonina/metabolismo , Modelos Animales de Enfermedad , Región CA1 Hipocampal/metabolismo , Región CA1 Hipocampal/efectos de los fármacos , Neuronas/metabolismo , Neuronas/efectos de los fármacos , Agonistas del Receptor de Serotonina 5-HT2/farmacologíaRESUMEN
Oxysterols are metabolites of cholesterol that regulate cholesterol homeostasis. Among these, the most abundant oxysterol is 27-hydroxycholesterol (27HC), which can cross the blood-brain barrier. Because 27HC functions as an endogenous selective estrogen receptor modulator, we hypothesize that 27HC binds to the estrogen receptor α (ERα) in the brain to regulate energy balance. Supporting this view, we found that delivering 27HC to the brain reduced food intake and activated proopiomelanocortin (POMC) neurons in the arcuate nucleus of the hypothalamus (POMCARH) in an ERα-dependent manner. In addition, we observed that inhibiting brain ERα, deleting ERα in POMC neurons, or chemogenetic inhibition of POMCARH neurons blocked the anorexigenic effects of 27HC. Mechanistically, we further revealed that 27HC stimulates POMCARH neurons by inhibiting the small conductance of the calcium-activated potassium (SK) channel. Together, our findings suggest that 27HC, through its interaction with ERα and modulation of the SK channel, inhibits food intake as a negative feedback mechanism against a surge in circulating cholesterol.