Neuroscience
Abstract
Liraglutide, a glucagon-like peptide-1 (GLP-1) analog, is approved for obesity treatment, but the specific neuronal sites that contribute to its therapeutic effects remain elusive. Here, we show that GLP-1 receptor–positive (GLP-1R–positive) neurons in the lateral septum (LSGLP-1R) play a critical role in mediating the anorectic and weight-loss effects of liraglutide. LSGLP-1R neurons were robustly activated by liraglutide, and chemogenetic activation of these neurons dramatically suppressed feeding. Targeted knockdown of GLP-1 receptors within the LS, but not in the hypothalamus, substantially attenuated liraglutide’s ability to inhibit feeding and lower body weight. The activity of LSGLP-1R neurons rapidly decreased during naturalistic feeding episodes, while synaptic inactivation of LSGLP-1R neurons diminished the anorexic effects triggered by liraglutide. Together, these findings offer critical insights into the functional role of LSGLP-1R neurons in the physiological regulation of energy homeostasis and delineate their instrumental role in mediating the pharmacological efficacy of liraglutide.
Authors
Zijun Chen, Xiaofei Deng, Cuijie Shi, Haiyang Jing, Yu Tian, Jiafeng Zhong, Gaowei Chen, Yunlong Xu, Yixiao Luo, Yingjie Zhu
The NR4A2/VGF pathway fuels inflammation-induced neurodegeneration via promoting neuronal glycolysis
Abstract
A disturbed balance between excitation and inhibition (E/I balance) is increasingly recognized as a key driver of neurodegeneration in multiple sclerosis (MS), a chronic inflammatory disease of the central nervous system. To understand how chronic hyperexcitability contributes to neuronal loss in MS, we transcriptionally profiled neurons from mice lacking inhibitory metabotropic glutamate signaling with shifted E/I balance and increased vulnerability to inflammation-induced neurodegeneration. This revealed a prominent induction of the nuclear receptor NR4A2 in neurons. Mechanistically, NR4A2 increased susceptibility to excitotoxicity by stimulating continuous VGF secretion leading to glycolysis-dependent neuronal cell death. Extending these findings to people with MS (pwMS), we observed increased VGF levels in serum and brain biopsies. Notably, neuron-specific deletion of Vgf in a mouse model of MS ameliorated neurodegeneration. These findings underscore the detrimental effect of a persistent metabolic shift driven by excitatory activity as a fundamental mechanism in inflammation-induced neurodegeneration.
Authors
Marcel S. Woo, Lukas C. Bal, Ingo Winschel, Elias Manca, Mark Walkenhorst, Bachar Sevgili, Jana K. Sonner, Giovanni Di Liberto, Christina Mayer, Lars Binkle-Ladisch, Nicola Rothammer, Lisa Unger, Lukas Raich, Alexandros Hadjilaou, Barbara Noli, Antonio L. Manai, Vanessa Vieira, Nina Meurs, Ingrid Wagner, Ole Pless, Cristina Cocco, Samuel B. Stephens, Markus Glatzel, Doron Merkler, Manuel A. Friese
Abstract
Most cases of human prion disease arise due to spontaneous misfolding of WT or mutant prion protein, yet recapitulating this event in animal models has proven challenging. It remains unclear whether spontaneous prion generation can occur within the mouse lifespan in the absence of protein overexpression and how disease-causing mutations affect prion strain properties. To address these issues, we generated knockin mice that express the misfolding-prone bank vole prion protein (BVPrP). While mice expressing WT BVPrP (I109 variant) remained free from neurological disease, a subset of mice expressing BVPrP with mutations (D178N or E200K) causing genetic prion disease developed progressive neurological illness. Brains from spontaneously ill knockin mice contained prion disease–specific neuropathological changes as well as atypical protease-resistant BVPrP. Moreover, brain extracts from spontaneously ill D178N- or E200K-mutant BVPrP–knockin mice exhibited prion seeding activity and transmitted disease to mice expressing WT BVPrP. Surprisingly, the properties of the D178N- and E200K-mutant prions appeared identical before and after transmission, suggesting that both mutations guide the formation of a similar atypical prion strain. These findings imply that knockin mice expressing mutant BVPrP spontaneously develop a bona fide prion disease and that mutations causing prion diseases may share a uniform initial mechanism of action.
Authors
Surabhi Mehra, Matthew E.C. Bourkas, Lech Kaczmarczyk, Erica Stuart, Hamza Arshad, Jennifer K. Griffin, Kathy L. Frost, Daniel J. Walsh, Surachai Supattapone, Stephanie A. Booth, Walker S. Jackson, Joel C. Watts
Abstract
Patients affected by glioma frequently suffer of epileptic discharges, however the causes of brain tumor-related epilepsy (BTRE) are still not completely understood. We investigated the mechanisms underlying BTRE by analyzing the effects of exosomes released by U87 glioma cells and by patient-derived glioma cells. Rat hippocampal neurons incubated for 24 h with these exosomes exhibited increased spontaneous firing, while their resting membrane potential shifted positively by 10-15 mV. Voltage clamp recordings demonstrated that the activation of the Na+ current shifted towards more hyperpolarized voltages by 10-15 mV. To understand the factors inducing hyperexcitability we focused on exosomal cytokines. Western Blot and ELISA assays show that TNF-α is present inside glioma-derived exosomes. Remarkably, incubation with TNF-α fully mimicked the phenotype induced by exosomes, with neurons firing continuously, while their resting membrane potential shifted positively. RT-PCR revealed that both exosomes and TNF-α induced over-expression of the voltage-gated Na channel Nav1.6, a low-threshold Na+ channel responsible for hyperexcitability. When neurons were preincubated with Infliximab, a specific TNF-α inhibitor, the hyperexcitability induced by exosomes and TNF-α were drastically reduced. We propose that Infliximab, an FDA approved drug to treat rheumatoid arthritis, could ameliorate the conditions of glioma patients suffering of BTRE.
Authors
Cesar Adolfo Sanchez Trivino, Renza Spelat, Federica Spada, Camilla D'Angelo, Ivana Manini, Irene Giulia Rolle, Tamara Ius, Pietro Parisse, Anna Menini, Daniela Cesselli, Miran Skrap, Fabrizia Cesca, Vincent Torre
Abstract
Patients with autism spectrum disorder (ASD) frequently experience sleep disturbance. Genetic mutations in Neuroligin-3 (NLG3) genes are highly correlative with ASD and sleep disturbance. However, the cellular and neural circuit bases of this correlation remain elusive. Here, we find the conditional knockout of NLG3 (NLG3-CKO) in the medial septum (MS) impairs social memory and reduces sleep. NLG3 knockout in MS causes hyperactivity of MS-GABA neurons during social avoidance and wakefulness. Activation of MSGABA neurons induces social memory deficits and sleep loss in C57BL/6 mice. In contrast, inactivation of these neurons ameliorates social memory deficits and sleep loss in NLG3-CKO mice. Sleep deprivation leads to social memory deficits, while social isolation causes sleep loss, both resulting in a reduction of NLG3 expression and an increase in activity of GABAergic neurons in MS from C57BL/6 mice. Furthermore, MS-GABA-innervated CA2 neurons specifically regulate social memory without impacting sleep, whereas MSGABA-innervating neurons in the preoptic area selectively control sleep without affecting social behavior. Together, these findings demonstrate that the hyperactive MS-GABA neurons impair social memory and disrupt sleep resulting from NLG3 knockout in MS, and achieve the modality specificity through their divergent downstream targets.
Authors
Haiyan Sun, Yu Shen, Pengtao Ni, Xin Liu, Yan Li, Zhentong Qiu, Jiawen Su, Yihan Wang, Miao Wu, Xiangxi Kong, Jun-Li Cao, Wei Xie, Shuming An
Abstract
Neovascular age-related macular degeneration (nAMD) remains a major cause of visual impairment and puts considerable burden on patients and health care systems. L-DOPA-treated Parkinson Disease (PD) patients have been shown to be partially protected from nAMD, but the mechanism remains unknown. Using murine models, combining 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD and laser-induced nAMD, standard PD treatment of L-DOPA/DOPA-decarboxylase inhibitor, or specific dopamine receptor inhibitors, we here demonstrate that L-DOPA treatment-induced increase of dopamine mediated dopamine receptor D2 (DRD2) signaling inhibits choroidal neovascularization independently of MPTP-associated nigrostriatal pathway lesion. Analyzing a retrospective cohort of more than two hundred thousand nAMD patients receiving anti-VEGF treatment from the French nationwide insurance database, we show that DRD2-agonist treated (PD) patients have a significantly delayed age of onset for nAMD (81.4 (±7.0) vs 79.4 (±8.1) years old, respectively, p<0.0001) and reduced need for anti-VEGF therapies (-0.6 injections per 100 mg/day daily dose of DRD2 agonists the second year of treatment), similar to the L-DOPA treatment. While providing a mechanistic explanation for an intriguing epidemiological observation, our findings suggest that systemic DRD2 agonists might constitute an adjuvant therapy to delay and reduce the need for anti-VEGF therapy in nAMD patients.
Authors
Thibaud Mathis, Florian Baudin, Anne-Sophie Mariet, Sébastien Augustin, Marion Bricout, Lauriane Przegralek, Christophe Roubeix, Éric Benzenine, Guillaume Blot, Caroline Nous, Laurent Kodjikian, Martine Mauget-Faÿsse, José-Alain Sahel, Robin Plevin, Christina Zeitz, Cécile Delarasse, Xavier Guillonneau, Catherine Creuzot-Garcher, Catherine Quantin, Stéphane Hunot, Florian Sennlaub
Abstract
Copy number variation (CNV) at 7q11.23 causes Williams-Beuren syndrome (WBS) and 7q microduplication syndrome (7Dup), neurodevelopmental disorders (NDDs) featuring intellectual disability accompanied by symmetrically opposite neurocognitive features. Although significant progress has been made in understanding the molecular mechanisms underlying 7q11.23-related pathophysiology, the propagation of CNV dosage across gene expression layers and their interplay remains elusive. Here we uncovered 7q11.23 dosage–dependent symmetrically opposite dynamics in neuronal differentiation and intrinsic excitability. By integrating transcriptomics, translatomics, and proteomics of patient-derived and isogenic induced neurons, we found that genes related to neuronal transmission follow 7q11.23 dosage and are transcriptionally controlled, while translational factors and ribosomal genes are posttranscriptionally buffered. Consistently, we found phosphorylated RPS6 (p-RPS6) downregulated in WBS and upregulated in 7Dup. Surprisingly, p-4EBP was changed in the opposite direction, reflecting dosage-specific changes in total 4EBP levels. This highlights different dosage-sensitive dyregulations of the mTOR pathway as well as distinct roles of p-RPS6 and p-4EBP during neurogenesis. Our work demonstrates the importance of multiscale disease modeling across molecular and functional layers, uncovers the pathophysiological relevance of ribosomal biogenesis in a paradigmatic pair of NDDs, and uncouples the roles of p-RPS6 and p-4EBP as mechanistically actionable relays in NDDs.
Authors
Marija Mihailovich, Pierre-Luc Germain, Reinald Shyti, Davide Pozzi, Roberta Noberini, Yansheng Liu, Davide Aprile, Erika Tenderini, Flavia Troglio, Sebastiano Trattaro, Sonia Fabris, Ummi Ciptasari, Marco Tullio Rigoli, Nicolò Caporale, Giuseppe D’Agostino, Filippo Mirabella, Alessandro Vitriolo, Daniele Capocefalo, Adrianos Skaros, Agnese Virginia Franchini, Sara Ricciardi, Ida Biunno, Antonino Neri, Nael Nadif Kasri, Tiziana Bonaldi, Rudolf Aebersold, Michela Matteoli, Giuseppe Testa
Abstract
Authors
Vicente Quiroz, Laura Planas-Serra, Abigail Sveden, Amy Tam, Hyo M. Kim, Umar Zubair, Dario Resch, Afshin Saffari, Matt C. Danzi, Stephan Züchner, Maya Chopra, Luca Schierbaum, Aurora Pujol, Erik A. Eklund, Darius Ebrahimi-Fakhari
Abstract
Reelin (RELN) is a secreted glycoprotein essential for cerebral cortex development. In humans, recessive RELN variants cause cortical and cerebellar malformations, while heterozygous variants were associated to epilepsy, autism and mild cortical abnormalities. However, their functional effects remain unknown. We identified inherited and de novo RELN missense variants in heterozygous patients with neuronal migration disorders (NMDs) as diverse as pachygyria and polymicrogyria. We investigated in culture and in the developing mouse cerebral cortex how different variants impacted RELN function. Polymicrogyria-associated variants behaved as gain-of-function showing an enhanced ability to induce neuronal aggregation, while those linked to pachygyria as loss-of-function leading to defective neuronal aggregation/migration. The pachygyria-associated de novo heterozygous RELN variants acted as dominant-negative by preventing wild-type RELN secretion in culture, animal models and patients, thereby causing dominant NMDs. We demonstrated how mutant RELN proteins in vitro and in vivo predict cortical malformation phenotypes, providing valuable insights into the pathogenesis of such disorders.
Authors
Martina Riva, Sofia Ferreira, Kotaro Hayashi, Yoann Saillour, Vera P. Medvedeva, Takao Honda, Kanehiro Hayashi, Claire Altersitz, Shahad Albadri, Marion Rosello, Julie Dang, Malo Serafini, Frédéric Causeret, Olivia J. Henry, Charles-Joris Roux, Céline Bellesme, Elena Freri, Dragana Josifova, Elena Parrini, Renzo Guerrini, Filippo Del Bene, Kazunori Nakajima, Nadia Bahi-Buisson, Alessandra Pierani
Abstract
Authors
Amandeep Jutla, Lauren C. Shuffrey, Stephen J. Guter, Kally C. O'Reilly, George M. Anderson, James S. Sutcliffe, Edwin H. Cook, Jeremy Veenstra-VanderWeele
Copyright © 2025 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)