Impairments of dendritic trees and spines have been found in many neurodegenerative diseases, including Alzheimer's disease (AD), in which the deficits of melatonin signal pathway were reported. Melatonin receptor 2 (MT2) is widely expressed in the hippocampus and mediates the biological functions of melatonin. It is known that melatonin application is protective to dendritic abnormalities in AD. However, whether MT2 is involved in the neuroprotection and the underlying mechanisms are not clear. Here, we first found that MT2 is dramatically reduced in the dendritic compartment upon the insult of oligomer Aβ. MT2 activation prevented the Aβ-induced disruption of dendritic complexity and spine. Importantly, activation of MT2 decreased cAMP, which in turn inactivated transcriptional factor CCAAT/enhancer-binding protein α(C/EBPα) to suppress miR-125b expression and elevate the expression of its target, GluN2A. In addition, miR-125b mimics fully blocked the protective effects of MT2 activation on dendritic trees and spines. Finally, injection of a lentivirus containing a miR-125b sponge into the hippocampus of APP/PS1 mice effectively rescued the dendritic abnormalities and learning/memory impairments. Our data demonstrated that the cAMP-C/EBPα/miR-125b/GluN2A signaling pathway is important to the neuroprotective effects of MT2 activation in Aβ-induced dendritic injuries and learning/memory disorders, providing a novel therapeutic target for the treatment of AD synaptopathy.
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http://dx.doi.org/10.1111/acel.12902 | DOI Listing |
Psychogeriatrics
January 2025
Department of Anesthesiology, The Fourth Hospital of Shijiazhuang, Shijiazhuang, China.
Background: Postoperative delirium (POD) poses significant clinical challenges regarding its diagnosis and treatment. Identifying biomarkers that can predict and diagnose POD is crucial for improving patient outcomes.
Methods: To explore potential biomarkers for POD, we conducted bulk RNA sequencing (bulk-seq) on peripheral blood samples from POD patients and healthy controls.
J Neurol
January 2025
Neuroimaging Research Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy.
Background: In multiple sclerosis (MS), susceptibility-weighted imaging (SWI) may reveal white matter lesions (WML) with a paramagnetic rim ("paramagnetic rim lesions" [PRLs]) or diffuse hypointensity ("core-sign lesions"), reflecting different stages of WML evolution.
Objective: Using the soma and neurite density imaging (SANDI) model on diffusion-weighted magnetic resonance imaging (MRI), we characterized microstructural abnormalities of MS PRLs and core-sign lesions and their clinical relevance.
Methods: Forty MS patients and 20 healthy controls (HC) underwent a 3 T brain MRI.
Acta Neurobiol Exp (Wars)
January 2025
Laboratory of Animal Models, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland.
The phosphatase and tensin homolog deleted on chromosome 10 (PTEN) gene is a critical tumor suppressor that plays an essential role in the development and functionality of the central nervous system. Located on chromosome 10 in humans and chromosome 19 in mice, PTEN encodes a protein that regulates cellular processes such as division, proliferation, growth, and survival by antagonizing the PI3K‑Akt‑mTOR signaling pathway. In neurons, PTEN dephosphorylates phosphatidylinositol‑3,4,5‑trisphosphate (PIP3) to PIP2, thereby modulating key signaling cascades involved in neurogenesis, neuronal migration, and synaptic plasticity.
View Article and Find Full Text PDFInt J Mol Sci
December 2024
Shenzhen Key Laboratory of Neuroimmunomodulation for Neurological Diseases, Shenzhen-Hong Kong Institute of Brain Science, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China.
Induced pluripotent stem cell (iPSC)-derived neurons (iNs) have been widely used as models of neurodevelopment and neurodegenerative diseases. Coating cell culture vessels with extracellular matrixes (ECMs) gives structural support and facilitates cell communication and differentiation, ultimately enhances neuronal functions. However, the relevance of different ECMs to the natural environment and their impact on neuronal differentiation have not been fully characterized.
View Article and Find Full Text PDFInt J Med Sci
January 2025
Guangdong Provincial Key Laboratory of Medical Immunology and Molecular Diagnostics, School of Medical Technology, Guangdong Medical University. Dongguan, Guangdong 523808, China.
Allergic diseases are a group of chronic inflammatory disorders driven by abnormal immune responses. Dendritic cells (DCs) play a pivotal role in the initiation and progression of allergic diseases by modulating T cell responses. Extensive progress has been made in characterizing crucial roles of metabolic reprogramming in the regulation of immune cell functions.
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